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Revision 494 - (show annotations) (download)
Tue Mar 2 11:53:12 2010 UTC (4 years, 1 month ago) by ph10
File size: 182068 byte(s)
If stdint.h is not available, include inttypes.h if available.

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 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
16 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
17
18
19 Version 8.01 19-Jan-2010
20 ------------------------
21
22 1. If a pattern contained a conditional subpattern with only one branch (in
23 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
24 computed the wrong minimum data length (which is of course zero for such
25 subpatterns). This could cause incorrect "no match" results.
26
27 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
28 the pattern is reset in the first branch, pcre_compile() failed with
29 "internal error: code overflow at offset...". This happened only when
30 the reset was to the original external option setting. (An optimization
31 abstracts leading options settings into an external setting, which was the
32 cause of this.)
33
34 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
35 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
36 assertion pattern did not match (meaning that the assertion was true), it
37 was incorrectly treated as false if the SKIP had been reached during the
38 matching. This also applied to assertions used as conditions.
39
40 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
41 assertion subpattern, including such a pattern used as a condition,
42 unpredictable results occurred, instead of the error return
43 PCRE_ERROR_DFA_UITEM.
44
45 5. The C++ GlobalReplace function was not working like Perl for the special
46 situation when an empty string is matched. It now does the fancy magic
47 stuff that is necessary.
48
49 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
50 removed. (These were left over from very, very early versions of PCRE.)
51
52 7. Some cosmetic changes to the code to make life easier when compiling it
53 as part of something else:
54
55 (a) Change DEBUG to PCRE_DEBUG.
56
57 (b) In pcre_compile(), rename the member of the "branch_chain" structure
58 called "current" as "current_branch", to prevent a collision with the
59 Linux macro when compiled as a kernel module.
60
61 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
62 prevent a collision with the Linux macro when compiled as a kernel
63 module.
64
65 8. In pcre_compile() there are some checks for integer overflows that used to
66 cast potentially large values to (double). This has been changed to that
67 when building, a check for int64_t is made, and if it is found, it is used
68 instead, thus avoiding the use of floating point arithmetic. (There is no
69 other use of FP in PCRE.) If int64_t is not found, the fallback is to
70 double.
71
72 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
73 2005 (difference between two addresses compared to an unsigned value).
74
75 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
76 custom one, because of the following reported problem in Windows:
77
78 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
79 under Win32.
80 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
81 therefore missing the function definition.
82 - The compiler thus generates a "C" signature for the test function.
83 - The linker fails to find the "C" function.
84 - PCRE fails to configure if asked to do so against libbz2.
85
86 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
87 messages were output:
88
89 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
90 rerunning libtoolize, to keep the correct libtool macros in-tree.
91 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
92
93 I have done both of these things.
94
95 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
96 most of the time, it *can* run out if it is given a pattern that contains a
97 runaway infinite recursion. I updated the discussion in the pcrestack man
98 page.
99
100 13. Now that we have gone to the x.xx style of version numbers, the minor
101 version may start with zero. Using 08 or 09 is a bad idea because users
102 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
103 interpreted as invalid octal numbers. I've updated the previous comment in
104 configure.ac, and also added a check that gives an error if 08 or 09 are
105 used.
106
107 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
108 causing partial matching to fail when the end of the subject matched \W
109 in a UTF-8 pattern where \W was quantified with a minimum of 3.
110
111 15. There were some discrepancies between the declarations in pcre_internal.h
112 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
113 their definitions. The declarations used "const uschar *" and the
114 definitions used USPTR. Even though USPTR is normally defined as "const
115 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
116 reported that: "This difference in casting confuses some C++ compilers, for
117 example, SunCC recognizes above declarations as different functions and
118 generates broken code for hbpcre." I have changed the declarations to use
119 USPTR.
120
121 16. GNU libtool is named differently on some systems. The autogen.sh script now
122 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
123 (FreeBSD).
124
125 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
126 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
127 comment: "Figure out how to create a longlong from a string: strtoll and
128 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
129 instance, but it only takes 2 args instead of 3!"
130
131 18. A subtle bug concerned with back references has been fixed by a change of
132 specification, with a corresponding code fix. A pattern such as
133 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
134 refers, was giving matches when it shouldn't. For example, xa=xaaa would
135 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
136 same bug. Such groups have to be quantified to be useful, or contained
137 inside another quantified group. (If there's no repetition, the reference
138 can never match.) The problem arises because, having left the group and
139 moved on to the rest of the pattern, a later failure that backtracks into
140 the group uses the captured value from the final iteration of the group
141 rather than the correct earlier one. I have fixed this in PCRE by forcing
142 any group that contains a reference to itself to be an atomic group; that
143 is, there cannot be any backtracking into it once it has completed. This is
144 similar to recursive and subroutine calls.
145
146
147 Version 8.00 19-Oct-09
148 ----------------------
149
150 1. The table for translating pcre_compile() error codes into POSIX error codes
151 was out-of-date, and there was no check on the pcre_compile() error code
152 being within the table. This could lead to an OK return being given in
153 error.
154
155 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
156 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
157 in a Windows environment.
158
159 3. The pcregrep --count option prints the count for each file even when it is
160 zero, as does GNU grep. However, pcregrep was also printing all files when
161 --files-with-matches was added. Now, when both options are given, it prints
162 counts only for those files that have at least one match. (GNU grep just
163 prints the file name in this circumstance, but including the count seems
164 more useful - otherwise, why use --count?) Also ensured that the
165 combination -clh just lists non-zero counts, with no names.
166
167 4. The long form of the pcregrep -F option was incorrectly implemented as
168 --fixed_strings instead of --fixed-strings. This is an incompatible change,
169 but it seems right to fix it, and I didn't think it was worth preserving
170 the old behaviour.
171
172 5. The command line items --regex=pattern and --regexp=pattern were not
173 recognized by pcregrep, which required --regex pattern or --regexp pattern
174 (with a space rather than an '='). The man page documented the '=' forms,
175 which are compatible with GNU grep; these now work.
176
177 6. No libpcreposix.pc file was created for pkg-config; there was just
178 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
179
180 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
181 when UCP support is not needed, by modifying the Python script that
182 generates it from Unicode data files. This should not matter if the module
183 is correctly used as a library, but I received one complaint about 50K of
184 unwanted data. My guess is that the person linked everything into his
185 program rather than using a library. Anyway, it does no harm.
186
187 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
188 was a minimum greater than 1 for a wide character in a possessive
189 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
190 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
191 character. Chaos in the form of incorrect output or a compiling loop could
192 result.
193
194 9. The restrictions on what a pattern can contain when partial matching is
195 requested for pcre_exec() have been removed. All patterns can now be
196 partially matched by this function. In addition, if there are at least two
197 slots in the offset vector, the offset of the earliest inspected character
198 for the match and the offset of the end of the subject are set in them when
199 PCRE_ERROR_PARTIAL is returned.
200
201 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
202 synonymous with PCRE_PARTIAL, for backwards compatibility, and
203 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
204 and may be more useful for multi-segment matching.
205
206 11. Partial matching with pcre_exec() is now more intuitive. A partial match
207 used to be given if ever the end of the subject was reached; now it is
208 given only if matching could not proceed because another character was
209 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
210 string "Z", which now yields "no match" instead of "partial match". In the
211 case of pcre_dfa_exec(), "no match" is given if every matching path for the
212 final character ended with (*FAIL).
213
214 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
215 if the pattern had a "must contain" character that was already found in the
216 earlier partial match, unless partial matching was again requested. For
217 example, with the pattern /dog.(body)?/, the "must contain" character is
218 "g". If the first part-match was for the string "dog", restarting with
219 "sbody" failed. This bug has been fixed.
220
221 13. The string returned by pcre_dfa_exec() after a partial match has been
222 changed so that it starts at the first inspected character rather than the
223 first character of the match. This makes a difference only if the pattern
224 starts with a lookbehind assertion or \b or \B (\K is not supported by
225 pcre_dfa_exec()). It's an incompatible change, but it makes the two
226 matching functions compatible, and I think it's the right thing to do.
227
228 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
229 so that the demonstration program is easily available in environments where
230 PCRE has not been installed from source.
231
232 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
233 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
234 library.
235
236 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
237 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
238 is not the first non-POSIX option to be added. Clearly some people find
239 these options useful.
240
241 17. If a caller to the POSIX matching function regexec() passes a non-zero
242 value for nmatch with a NULL value for pmatch, the value of
243 nmatch is forced to zero.
244
245 18. RunGrepTest did not have a test for the availability of the -u option of
246 the diff command, as RunTest does. It now checks in the same way as
247 RunTest, and also checks for the -b option.
248
249 19. If an odd number of negated classes containing just a single character
250 interposed, within parentheses, between a forward reference to a named
251 subpattern and the definition of the subpattern, compilation crashed with
252 an internal error, complaining that it could not find the referenced
253 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
254 [The bug was that it was starting one character too far in when skipping
255 over the character class, thus treating the ] as data rather than
256 terminating the class. This meant it could skip too much.]
257
258 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
259 /g option in pcretest when the pattern contains \K, which makes it possible
260 to have an empty string match not at the start, even when the pattern is
261 anchored. Updated pcretest and pcredemo to use this option.
262
263 21. If the maximum number of capturing subpatterns in a recursion was greater
264 than the maximum at the outer level, the higher number was returned, but
265 with unset values at the outer level. The correct (outer level) value is
266 now given.
267
268 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
269 PCRE did not set those parentheses (unlike Perl). I have now found a way to
270 make it do so. The string so far is captured, making this feature
271 compatible with Perl.
272
273 23. The tests have been re-organized, adding tests 11 and 12, to make it
274 possible to check the Perl 5.10 features against Perl 5.10.
275
276 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
277 pattern matches a fixed length string. PCRE did not allow this; now it
278 does. Neither allows recursion.
279
280 25. I finally figured out how to implement a request to provide the minimum
281 length of subject string that was needed in order to match a given pattern.
282 (It was back references and recursion that I had previously got hung up
283 on.) This code has now been added to pcre_study(); it finds a lower bound
284 to the length of subject needed. It is not necessarily the greatest lower
285 bound, but using it to avoid searching strings that are too short does give
286 some useful speed-ups. The value is available to calling programs via
287 pcre_fullinfo().
288
289 26. While implementing 25, I discovered to my embarrassment that pcretest had
290 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
291 study optimizations had never been tested with that matching function.
292 Oops. What is worse, even when it was passed study data, there was a bug in
293 pcre_dfa_exec() that meant it never actually used it. Double oops. There
294 were also very few tests of studied patterns with pcre_dfa_exec().
295
296 27. If (?| is used to create subpatterns with duplicate numbers, they are now
297 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
298 on the other side of the coin, they are no longer allowed to have different
299 names, because these cannot be distinguished in PCRE, and this has caused
300 confusion. (This is a difference from Perl.)
301
302 28. When duplicate subpattern names are present (necessarily with different
303 numbers, as required by 27 above), and a test is made by name in a
304 conditional pattern, either for a subpattern having been matched, or for
305 recursion in such a pattern, all the associated numbered subpatterns are
306 tested, and the overall condition is true if the condition is true for any
307 one of them. This is the way Perl works, and is also more like the way
308 testing by number works.
309
310
311 Version 7.9 11-Apr-09
312 ---------------------
313
314 1. When building with support for bzlib/zlib (pcregrep) and/or readline
315 (pcretest), all targets were linked against these libraries. This included
316 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
317 libraries. This caused unwanted dependencies to be created. This problem
318 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
319 pcretest is linked with readline.
320
321 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
322 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
323 moved outside it again, because FALSE and TRUE are already defined in AIX,
324 but BOOL is not.
325
326 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
327 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
328
329 4. The pcregrep documentation said spaces were inserted as well as colons (or
330 hyphens) following file names and line numbers when outputting matching
331 lines. This is not true; no spaces are inserted. I have also clarified the
332 wording for the --colour (or --color) option.
333
334 5. In pcregrep, when --colour was used with -o, the list of matching strings
335 was not coloured; this is different to GNU grep, so I have changed it to be
336 the same.
337
338 6. When --colo(u)r was used in pcregrep, only the first matching substring in
339 each matching line was coloured. Now it goes on to look for further matches
340 of any of the test patterns, which is the same behaviour as GNU grep.
341
342 7. A pattern that could match an empty string could cause pcregrep to loop; it
343 doesn't make sense to accept an empty string match in pcregrep, so I have
344 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
345 seems to be how GNU grep behaves.
346
347 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
348 start or after a newline", because the conditional assertion was not being
349 correctly handled. The rule now is that both the assertion and what follows
350 in the first alternative must satisfy the test.
351
352 9. If auto-callout was enabled in a pattern with a conditional group whose
353 condition was an assertion, PCRE could crash during matching, both with
354 pcre_exec() and pcre_dfa_exec().
355
356 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
357 used for matching.
358
359 11. Unicode property support in character classes was not working for
360 characters (bytes) greater than 127 when not in UTF-8 mode.
361
362 12. Added the -M command line option to pcretest.
363
364 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
365
366 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
367
368 16. Added comments and documentation about mis-use of no_arg in the C++
369 wrapper.
370
371 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
372 from Martin Jerabek that uses macro names for all relevant character and
373 string constants.
374
375 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
376 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
377 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
378 these, but not everybody uses configure.
379
380 19. A conditional group that had only one branch was not being correctly
381 recognized as an item that could match an empty string. This meant that an
382 enclosing group might also not be so recognized, causing infinite looping
383 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
384 with the subject "ab", where knowledge that the repeated group can match
385 nothing is needed in order to break the loop.
386
387 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
388 exec(), but without supplying a callout function, matching went wrong.
389
390 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
391 leak if the size of the offset vector was greater than 30. When the vector
392 is smaller, the saved offsets during recursion go onto a local stack
393 vector, but for larger vectors malloc() is used. It was failing to free
394 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
395 error, in fact).
396
397 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
398 heapframe that is used only when UTF-8 support is enabled. This caused no
399 problem, but was untidy.
400
401 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
402 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
403 included within another project.
404
405 24. Steven Van Ingelgem's patches to add more options to the CMake support,
406 slightly modified by me:
407
408 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
409 not building pcregrep.
410
411 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
412 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
413
414 25. Forward references, both numeric and by name, in patterns that made use of
415 duplicate group numbers, could behave incorrectly or give incorrect errors,
416 because when scanning forward to find the reference group, PCRE was not
417 taking into account the duplicate group numbers. A pattern such as
418 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
419
420 26. Changed a few more instances of "const unsigned char *" to USPTR, making
421 the feature of a custom pointer more persuasive (as requested by a user).
422
423 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
424 pcretest.c, inside #ifndefs, because it seems they are sometimes already
425 pre-defined.
426
427 28. Added support for (*UTF8) at the start of a pattern.
428
429 29. Arrange for flags added by the "release type" setting in CMake to be shown
430 in the configuration summary.
431
432
433 Version 7.8 05-Sep-08
434 ---------------------
435
436 1. Replaced UCP searching code with optimized version as implemented for Ad
437 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
438 stage table and inline lookup instead of a function, giving speed ups of 2
439 to 5 times on some simple patterns that I tested. Permission was given to
440 distribute the MultiStage2.py script that generates the tables (it's not in
441 the tarball, but is in the Subversion repository).
442
443 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
444 scripts.
445
446 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
447 a group with a zero qualifier. The result of the study could be incorrect,
448 or the function might crash, depending on the pattern.
449
450 4. Caseless matching was not working for non-ASCII characters in back
451 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
452 It now works when Unicode Property Support is available.
453
454 5. In pcretest, an escape such as \x{de} in the data was always generating
455 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
456 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
457 truncation.
458
459 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
460
461 7. Added two (int) casts to pcregrep when printing the difference of two
462 pointers, in case they are 64-bit values.
463
464 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
465 test 2 if it fails.
466
467 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
468 and a #define of that name to empty if it is not externally set. This is to
469 allow users of MSVC to set it if necessary.
470
471 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
472 the convenience functions in the pcre_get.c source file.
473
474 11. An option change at the start of a pattern that had top-level alternatives
475 could cause overwriting and/or a crash. This command provoked a crash in
476 some environments:
477
478 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
479
480 This potential security problem was recorded as CVE-2008-2371.
481
482 12. For a pattern where the match had to start at the beginning or immediately
483 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
484 pcre_dfa_exec() could read past the end of the passed subject if there was
485 no match. To help with detecting such bugs (e.g. with valgrind), I modified
486 pcretest so that it places the subject at the end of its malloc-ed buffer.
487
488 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
489 exec() might read past the end of the data buffer in UTF-8 mode.
490
491 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
492 the data contained the byte 0x85 as part of a UTF-8 character within its
493 first line. This applied both to normal and DFA matching.
494
495 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
496 /^[^d]*?$/8 failed to match "abc".
497
498 16. Added a missing copyright notice to pcrecpp_internal.h.
499
500 17. Make it more clear in the documentation that values returned from
501 pcre_exec() in ovector are byte offsets, not character counts.
502
503 18. Tidied a few places to stop certain compilers from issuing warnings.
504
505 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
506 supplied by Stefan Weber. I made a further small update for 7.8 because
507 there is a change of source arrangements: the pcre_searchfuncs.c module is
508 replaced by pcre_ucd.c.
509
510
511 Version 7.7 07-May-08
512 ---------------------
513
514 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
515 a string to a long long, pretend we don't even have a long long." This is
516 done by checking for the strtoq, strtoll, and _strtoi64 functions.
517
518 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
519 pre-7.6 versions, which defined a global no_arg variable instead of putting
520 it in the RE class. (See also #8 below.)
521
522 3. Remove a line of dead code, identified by coverity and reported by Nuno
523 Lopes.
524
525 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
526
527 (1) The include/exclude patterns were being applied to the whole pathnames
528 of files, instead of just to the final components.
529
530 (2) If there was more than one level of directory, the subdirectories were
531 skipped unless they satisfied the include/exclude conditions. This is
532 inconsistent with GNU grep (and could even be seen as contrary to the
533 pcregrep specification - which I improved to make it absolutely clear).
534 The action now is always to scan all levels of directory, and just
535 apply the include/exclude patterns to regular files.
536
537 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
538 --exclude_dir in the tests to avoid scanning .svn directories.
539
540 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
541 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
542 doesn't support NULs in patterns.
543
544 7. Added some missing "const"s to declarations of static tables in
545 pcre_compile.c and pcre_dfa_exec.c.
546
547 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
548 caused by fix #2 above. (Subsequently also a second patch to fix the
549 first patch. And a third patch - this was a messy problem.)
550
551 9. Applied Craig's patch to remove the use of push_back().
552
553 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
554 matching function regexec().
555
556 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
557 which, however, unlike Perl's \g{...}, are subroutine calls, not back
558 references. PCRE supports relative numbers with this syntax (I don't think
559 Oniguruma does).
560
561 12. Previously, a group with a zero repeat such as (...){0} was completely
562 omitted from the compiled regex. However, this means that if the group
563 was called as a subroutine from elsewhere in the pattern, things went wrong
564 (an internal error was given). Such groups are now left in the compiled
565 pattern, with a new opcode that causes them to be skipped at execution
566 time.
567
568 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
569 to the way PCRE behaves:
570
571 (a) A lone ] character is dis-allowed (Perl treats it as data).
572
573 (b) A back reference to an unmatched subpattern matches an empty string
574 (Perl fails the current match path).
575
576 (c) A data ] in a character class must be notated as \] because if the
577 first data character in a class is ], it defines an empty class. (In
578 Perl it is not possible to have an empty class.) The empty class []
579 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
580 The negative empty class [^] matches any one character, independently
581 of the DOTALL setting.
582
583 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
584 non-existent subpattern following a character class starting with ']' and
585 containing () gave an internal compiling error instead of "reference to
586 non-existent subpattern". Fortunately, when the pattern did exist, the
587 compiled code was correct. (When scanning forwards to check for the
588 existencd of the subpattern, it was treating the data ']' as terminating
589 the class, so got the count wrong. When actually compiling, the reference
590 was subsequently set up correctly.)
591
592 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
593 it was being rejected as not supported by pcre_dfa_exec(), even though
594 other assertions are supported. I have made pcre_dfa_exec() support
595 (*FAIL).
596
597 16. The implementation of 13c above involved the invention of a new opcode,
598 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
599 cannot be changed at match time, I realized I could make a small
600 improvement to matching performance by compiling OP_ALLANY instead of
601 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
602 on the OP_ANY path.
603
604 17. Compiling pcretest on Windows with readline support failed without the
605 following two fixes: (1) Make the unistd.h include conditional on
606 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
607
608 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
609 ncurses library to be included for pcretest when ReadLine support is
610 requested, but also to allow for it to be overridden. This patch came from
611 Daniel Bergström.
612
613 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
614 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
615 any errors with the current Unicode tables. Thanks to Peter Kankowski for
616 spotting this.
617
618
619 Version 7.6 28-Jan-08
620 ---------------------
621
622 1. A character class containing a very large number of characters with
623 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
624 overflow.
625
626 2. Patch to cut out the "long long" test in pcrecpp_unittest when
627 HAVE_LONG_LONG is not defined.
628
629 3. Applied Christian Ehrlicher's patch to update the CMake build files to
630 bring them up to date and include new features. This patch includes:
631
632 - Fixed PH's badly added libz and libbz2 support.
633 - Fixed a problem with static linking.
634 - Added pcredemo. [But later removed - see 7 below.]
635 - Fixed dftables problem and added an option.
636 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
637 HAVE_LONG_LONG.
638 - Added readline support for pcretest.
639 - Added an listing of the option settings after cmake has run.
640
641 4. A user submitted a patch to Makefile that makes it easy to create
642 "pcre.dll" under mingw when using Configure/Make. I added stuff to
643 Makefile.am that cause it to include this special target, without
644 affecting anything else. Note that the same mingw target plus all
645 the other distribution libraries and programs are now supported
646 when configuring with CMake (see 6 below) instead of with
647 Configure/Make.
648
649 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
650 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
651 exported in the Windows port". It has not yet been confirmed that the patch
652 solves the problem, but it does no harm.
653
654 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
655 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
656 with CMake, and also correct the comment about stack recursion.
657
658 7. Remove the automatic building of pcredemo from the ./configure system and
659 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
660 of a program that users should build themselves after PCRE is installed, so
661 building it automatically is not really right. What is more, it gave
662 trouble in some build environments.
663
664 8. Further tidies to CMakeLists.txt from Sheri and Christian.
665
666
667 Version 7.5 10-Jan-08
668 ---------------------
669
670 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
671 values in parens when parsing an RE using the C++ wrapper."
672
673 2. Negative specials like \S did not work in character classes in UTF-8 mode.
674 Characters greater than 255 were excluded from the class instead of being
675 included.
676
677 3. The same bug as (2) above applied to negated POSIX classes such as
678 [:^space:].
679
680 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
681 defined or documented. It seems to have been a typo for PCRE_STATIC, so
682 I have changed it.
683
684 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
685 first named subpattern) and a construct such as (?&a) would reference the
686 first named subpattern whose name started with "a" (in other words, the
687 length check was missing). Both these problems are fixed. "Subpattern name
688 expected" is now given for (?&) (a zero-length name), and this patch also
689 makes it give the same error for \k'' (previously it complained that that
690 was a reference to a non-existent subpattern).
691
692 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
693 this is right because (?- can be followed by option settings as well as by
694 digits. I have, however, made the messages clearer.
695
696 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
697 than the number used in the conditional) now cause a compile-time error.
698 This is actually not compatible with Perl, which accepts such patterns, but
699 treats the conditional as always being FALSE (as PCRE used to), but it
700 seems to me that giving a diagnostic is better.
701
702 8. Change "alphameric" to the more common word "alphanumeric" in comments
703 and messages.
704
705 9. Fix two occurrences of "backslash" in comments that should have been
706 "backspace".
707
708 10. Remove two redundant lines of code that can never be obeyed (their function
709 was moved elsewhere).
710
711 11. The program that makes PCRE's Unicode character property table had a bug
712 which caused it to generate incorrect table entries for sequences of
713 characters that have the same character type, but are in different scripts.
714 It amalgamated them into a single range, with the script of the first of
715 them. In other words, some characters were in the wrong script. There were
716 thirteen such cases, affecting characters in the following ranges:
717
718 U+002b0 - U+002c1
719 U+0060c - U+0060d
720 U+0061e - U+00612
721 U+0064b - U+0065e
722 U+0074d - U+0076d
723 U+01800 - U+01805
724 U+01d00 - U+01d77
725 U+01d9b - U+01dbf
726 U+0200b - U+0200f
727 U+030fc - U+030fe
728 U+03260 - U+0327f
729 U+0fb46 - U+0fbb1
730 U+10450 - U+1049d
731
732 12. The -o option (show only the matching part of a line) for pcregrep was not
733 compatible with GNU grep in that, if there was more than one match in a
734 line, it showed only the first of them. It now behaves in the same way as
735 GNU grep.
736
737 13. If the -o and -v options were combined for pcregrep, it printed a blank
738 line for every non-matching line. GNU grep prints nothing, and pcregrep now
739 does the same. The return code can be used to tell if there were any
740 non-matching lines.
741
742 14. Added --file-offsets and --line-offsets to pcregrep.
743
744 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
745 infinitely looping recursion. The bug was that positive lookaheads were not
746 being skipped when checking for a possible empty match (negative lookaheads
747 and both kinds of lookbehind were skipped).
748
749 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
750 inclusion of <windows.h> to before rather than after the definition of
751 INVALID_FILE_ATTRIBUTES (patch from David Byron).
752
753 17. Specifying a possessive quantifier with a specific limit for a Unicode
754 character property caused pcre_compile() to compile bad code, which led at
755 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
756 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
757 caused the error; without that there was no problem.
758
759 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
760
761 19. Added --enable-pcretest-libreadline.
762
763 20. In pcrecpp.cc, the variable 'count' was incremented twice in
764 RE::GlobalReplace(). As a result, the number of replacements returned was
765 double what it should be. I removed one of the increments, but Craig sent a
766 later patch that removed the other one (the right fix) and added unit tests
767 that check the return values (which was not done before).
768
769 21. Several CMake things:
770
771 (1) Arranged that, when cmake is used on Unix, the libraries end up with
772 the names libpcre and libpcreposix, not just pcre and pcreposix.
773
774 (2) The above change means that pcretest and pcregrep are now correctly
775 linked with the newly-built libraries, not previously installed ones.
776
777 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
778
779 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
780 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
781 UTF-8 newline character). The key issue is that the pattern starts .*;
782 this means that the match must be either at the beginning, or after a
783 newline. The bug was in the code for advancing after a failed match and
784 checking that the new position followed a newline. It was not taking
785 account of UTF-8 characters correctly.
786
787 23. PCRE was behaving differently from Perl in the way it recognized POSIX
788 character classes. PCRE was not treating the sequence [:...:] as a
789 character class unless the ... were all letters. Perl, however, seems to
790 allow any characters between [: and :], though of course it rejects as
791 unknown any "names" that contain non-letters, because all the known class
792 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
793 for example, whereas PCRE did not - it did not recognize a POSIX character
794 class. This seemed a bit dangerous, so the code has been changed to be
795 closer to Perl. The behaviour is not identical to Perl, because PCRE will
796 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
797 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
798 Perl does, and where it didn't before.
799
800 24. Rewrite so as to remove the single use of %n from pcregrep because in some
801 Windows environments %n is disabled by default.
802
803
804 Version 7.4 21-Sep-07
805 ---------------------
806
807 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
808 means that a class such as [\s] counted as "explicit reference to CR or
809 LF". That isn't really right - the whole point of the change was to try to
810 help when there was an actual mention of one of the two characters. So now
811 the change happens only if \r or \n (or a literal CR or LF) character is
812 encountered.
813
814 2. The 32-bit options word was also used for 6 internal flags, but the numbers
815 of both had grown to the point where there were only 3 bits left.
816 Fortunately, there was spare space in the data structure, and so I have
817 moved the internal flags into a new 16-bit field to free up more option
818 bits.
819
820 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
821 but did not set the internal JCHANGED flag - either of these is enough to
822 control the way the "get" function works - but the PCRE_INFO_JCHANGED
823 facility is supposed to tell if (?J) was ever used, so now (?J) at the
824 start sets both bits.
825
826 4. Added options (at build time, compile time, exec time) to change \R from
827 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
828
829 5. doc/pcresyntax.html was missing from the distribution.
830
831 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
832 compatibility, even though it is no longer used.
833
834 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
835 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
836 windows.h file is present (where different names are used). [This was
837 reversed later after testing - see 16 below.]
838
839 8. Changed all #include <config.h> to #include "config.h". There were also
840 some further <pcre.h> cases that I changed to "pcre.h".
841
842 9. When pcregrep was used with the --colour option, it missed the line ending
843 sequence off the lines that it output.
844
845 10. It was pointed out to me that arrays of string pointers cause lots of
846 relocations when a shared library is dynamically loaded. A technique of
847 using a single long string with a table of offsets can drastically reduce
848 these. I have refactored PCRE in four places to do this. The result is
849 dramatic:
850
851 Originally: 290
852 After changing UCP table: 187
853 After changing error message table: 43
854 After changing table of "verbs" 36
855 After changing table of Posix names 22
856
857 Thanks to the folks working on Gregex for glib for this insight.
858
859 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
860 unicode-properties was also set.
861
862 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
863
864 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
865 checked only for CRLF.
866
867 14. Added casts to pcretest.c to avoid compiler warnings.
868
869 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
870
871 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
872 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
873 entirely. This removes changes made in 7 above.
874
875 17. The CMake files have been updated, and there is now more information about
876 building with CMake in the NON-UNIX-USE document.
877
878
879 Version 7.3 28-Aug-07
880 ---------------------
881
882 1. In the rejigging of the build system that eventually resulted in 7.1, the
883 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
884 brackets there is not right, since it causes compilers to look for an
885 installed pcre.h, not the version that is in the source that is being
886 compiled (which of course may be different). I have changed it back to:
887
888 #include "pcre.h"
889
890 I have a vague recollection that the change was concerned with compiling in
891 different directories, but in the new build system, that is taken care of
892 by the VPATH setting the Makefile.
893
894 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
895 when the subject happened to end in the byte 0x85 (e.g. if the last
896 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
897 characters but of course it shouldn't be taken as a newline when it is part
898 of another character. The bug was that, for an unlimited repeat of . in
899 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
900 characters when looking for a newline.
901
902 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
903
904 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
905 in debug output.
906
907 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
908 long printing in the pcrecpp unittest when running under MinGW.
909
910 6. ESC_K was left out of the EBCDIC table.
911
912 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
913 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
914 limit also applies to "virtual nesting" when a pattern is recursive, and in
915 this case 1000 isn't so big. I have been able to remove this limit at the
916 expense of backing off one optimization in certain circumstances. Normally,
917 when pcre_exec() would call its internal match() function recursively and
918 immediately return the result unconditionally, it uses a "tail recursion"
919 feature to save stack. However, when a subpattern that can match an empty
920 string has an unlimited repetition quantifier, it no longer makes this
921 optimization. That gives it a stack frame in which to save the data for
922 checking that an empty string has been matched. Previously this was taken
923 from the 1000-entry workspace that had been reserved. So now there is no
924 explicit limit, but more stack is used.
925
926 8. Applied Daniel's patches to solve problems with the import/export magic
927 syntax that is required for Windows, and which was going wrong for the
928 pcreposix and pcrecpp parts of the library. These were overlooked when this
929 problem was solved for the main library.
930
931 9. There were some crude static tests to avoid integer overflow when computing
932 the size of patterns that contain repeated groups with explicit upper
933 limits. As the maximum quantifier is 65535, the maximum group length was
934 set at 30,000 so that the product of these two numbers did not overflow a
935 32-bit integer. However, it turns out that people want to use groups that
936 are longer than 30,000 bytes (though not repeat them that many times).
937 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
938 made it possible to implement the integer overflow checks in a much more
939 dynamic way, which I have now done. The artificial limitation on group
940 length has been removed - we now have only the limit on the total length of
941 the compiled pattern, which depends on the LINK_SIZE setting.
942
943 10. Fixed a bug in the documentation for get/copy named substring when
944 duplicate names are permitted. If none of the named substrings are set, the
945 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
946 empty string.
947
948 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
949 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
950 because the ] is interpreted as the first data character and the
951 terminating ] is not found. PCRE has been made compatible with Perl in this
952 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
953 cause memory overwriting.
954
955 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
956 string has been matched (to stop an infinite loop). It was not recognizing
957 a conditional subpattern that could match an empty string if that
958 subpattern was within another subpattern. For example, it looped when
959 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
960 condition was not nested. This bug has been fixed.
961
962 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
963 past the start of the subject in the presence of bytes with the top bit
964 set, for example "\x8aBCD".
965
966 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
967 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
968
969 14. Optimized (?!) to (*FAIL).
970
971 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
972 This restricts code points to be within the range 0 to 0x10FFFF, excluding
973 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
974 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
975 does: it's just the validity check that is more restrictive.
976
977 16. Inserted checks for integer overflows during escape sequence (backslash)
978 processing, and also fixed erroneous offset values for syntax errors during
979 backslash processing.
980
981 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
982 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
983
984 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
985 caused an overrun.
986
987 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
988 something other than just ASCII characters) inside a group that had an
989 unlimited repeat caused a loop at compile time (while checking to see
990 whether the group could match an empty string).
991
992 20. Debugging a pattern containing \p or \P could cause a crash. For example,
993 [\P{Any}] did so. (Error in the code for printing property names.)
994
995 21. An orphan \E inside a character class could cause a crash.
996
997 22. A repeated capturing bracket such as (A)? could cause a wild memory
998 reference during compilation.
999
1000 23. There are several functions in pcre_compile() that scan along a compiled
1001 expression for various reasons (e.g. to see if it's fixed length for look
1002 behind). There were bugs in these functions when a repeated \p or \P was
1003 present in the pattern. These operators have additional parameters compared
1004 with \d, etc, and these were not being taken into account when moving along
1005 the compiled data. Specifically:
1006
1007 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1008 length.
1009
1010 (b) An item such as \pL+ within a repeated group could cause crashes or
1011 loops.
1012
1013 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1014 "reference to non-existent subpattern" error.
1015
1016 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1017
1018 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1019 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1020
1021 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1022
1023 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1024 character were causing crashes (broken optimization).
1025
1026 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1027 \p or \P) caused a compile-time loop.
1028
1029 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1030 break. For example, the unstudied pattern [\r\n]A does not match the string
1031 "\r\nA" because change 7.0/46 below moves the current point on by two
1032 characters after failing to match at the start. However, the pattern \nA
1033 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1034 the same is true. There doesn't seem any very clean way out of this, but
1035 what I have chosen to do makes the common cases work: PCRE now takes note
1036 of whether there can be an explicit match for \r or \n anywhere in the
1037 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1038 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1039 pattern has explicit CR or LF references.
1040
1041 29. Added (*CR) etc for changing newline setting at start of pattern.
1042
1043
1044 Version 7.2 19-Jun-07
1045 ---------------------
1046
1047 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1048 which is apparently normally available under Windows.
1049
1050 2. Re-jig the pcregrep tests with different newline settings in an attempt
1051 to make them independent of the local environment's newline setting.
1052
1053 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1054
1055 4. Some of the "internals" tests were previously cut out when the link size
1056 was not 2, because the output contained actual offsets. The recent new
1057 "Z" feature of pcretest means that these can be cut out, making the tests
1058 usable with all link sizes.
1059
1060 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1061 stack recursion. This gives a massive performance boost under BSD, but just
1062 a small improvement under Linux. However, it saves one field in the frame
1063 in all cases.
1064
1065 6. Added more features from the forthcoming Perl 5.10:
1066
1067 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1068 recursion call. It refers to the nth most recently opened parentheses.
1069
1070 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1071 to be opened parentheses.
1072
1073 (c) Conditions that refer to capturing parentheses can be specified
1074 relatively, for example, (?(-2)... or (?(+3)...
1075
1076 (d) \K resets the start of the current match so that everything before
1077 is not part of it.
1078
1079 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1080
1081 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1082 reference syntax.
1083
1084 (g) (?| introduces a group in which the numbering of parentheses in each
1085 alternative starts with the same number.
1086
1087 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1088
1089 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1090 PCRE_INFO_JCHANGED.
1091
1092 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1093 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1094 for detecting groups that can match an empty string.
1095
1096 9. A pattern with a very large number of alternatives (more than several
1097 hundred) was running out of internal workspace during the pre-compile
1098 phase, where pcre_compile() figures out how much memory will be needed. A
1099 bit of new cunning has reduced the workspace needed for groups with
1100 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1101 workspace instead of running out of the 4096 that are available.
1102
1103 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1104
1105 11. Applied patch from Google to remove an optimization that didn't quite work.
1106 The report of the bug said:
1107
1108 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1109 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1110 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1111
1112 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1113 it matched the wrong number of bytes.
1114
1115
1116 Version 7.1 24-Apr-07
1117 ---------------------
1118
1119 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1120 that is more "standard", making use of automake and other Autotools. There
1121 is some re-arrangement of the files and adjustment of comments consequent
1122 on this.
1123
1124 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1125 for recursive directory scanning broke on some systems because the files
1126 are not scanned in any specific order and on different systems the order
1127 was different. A call to "sort" has been inserted into RunGrepTest for the
1128 approprate test as a short-term fix. In the longer term there may be an
1129 alternative.
1130
1131 3. I had an email from Eric Raymond about problems translating some of PCRE's
1132 man pages to HTML (despite the fact that I distribute HTML pages, some
1133 people do their own conversions for various reasons). The problems
1134 concerned the use of low-level troff macros .br and .in. I have therefore
1135 removed all such uses from the man pages (some were redundant, some could
1136 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1137 HTML has been updated to handle .nf/.fi and to complain if it encounters
1138 .br or .in.
1139
1140 4. Updated comments in configure.ac that get placed in config.h.in and also
1141 arranged for config.h to be included in the distribution, with the name
1142 config.h.generic, for the benefit of those who have to compile without
1143 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1144
1145 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1146 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1147 makevp.bat for the current PCRE, using the additional files
1148 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1149
1150 6. A Windows user reported a minor discrepancy with test 2, which turned out
1151 to be caused by a trailing space on an input line that had got lost in his
1152 copy. The trailing space was an accident, so I've just removed it.
1153
1154 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1155 that is needed.
1156
1157 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1158 as "const" (a) because they are and (b) because it helps the PHP
1159 maintainers who have recently made a script to detect big data structures
1160 in the php code that should be moved to the .rodata section. I remembered
1161 to update Builducptable as well, so it won't revert if ucptable.h is ever
1162 re-created.
1163
1164 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1165 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1166 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1167 support is not required. This saves 1.5-2K of code, which is important in
1168 some applications.
1169
1170 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1171 so as not to refer to the tables, even though these functions will never be
1172 called when UTF-8 support is disabled. Otherwise there are problems with a
1173 shared library.
1174
1175 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1176
1177 (a) It was defining its arguments as char * instead of void *.
1178
1179 (b) It was assuming that all moves were upwards in memory; this was true
1180 a long time ago when I wrote it, but is no longer the case.
1181
1182 The emulated memove() is provided for those environments that have neither
1183 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1184 is clearly not the case, as these two bugs were recently reported.
1185
1186 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1187 and Detrail to create the HTML documentation, the .txt form of the man
1188 pages, and it removes trailing spaces from listed files. It also creates
1189 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1190 case, it wraps all the #defines with #ifndefs. This script should be run
1191 before "make dist".
1192
1193 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1194 with Unicode property support.
1195
1196 (a) For a maximizing quantifier, if the two different cases of the
1197 character were of different lengths in their UTF-8 codings (there are
1198 some cases like this - I found 11), and the matching function had to
1199 back up over a mixture of the two cases, it incorrectly assumed they
1200 were both the same length.
1201
1202 (b) When PCRE was configured to use the heap rather than the stack for
1203 recursion during matching, it was not correctly preserving the data for
1204 the other case of a UTF-8 character when checking ahead for a match
1205 while processing a minimizing repeat. If the check also involved
1206 matching a wide character, but failed, corruption could cause an
1207 erroneous result when trying to check for a repeat of the original
1208 character.
1209
1210 13. Some tidying changes to the testing mechanism:
1211
1212 (a) The RunTest script now detects the internal link size and whether there
1213 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1214 values substituted by "configure". (The RunGrepTest script already did
1215 this for UTF-8.) The configure.ac script no longer substitutes the
1216 relevant variables.
1217
1218 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1219 with length and offset values. This means that the output is different
1220 for different internal link sizes. Test 2 is skipped for link sizes
1221 other than 2 because of this, bypassing the problem. Unfortunately,
1222 there was also a test in test 3 (the locale tests) that used /B and
1223 failed for link sizes other than 2. Rather than cut the whole test out,
1224 I have added a new /Z option to pcretest that replaces the length and
1225 offset values with spaces. This is now used to make test 3 independent
1226 of link size. (Test 2 will be tidied up later.)
1227
1228 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1229 segmentation fault instead of returning the appropriate error message.
1230
1231 15. In multiline mode when the newline sequence was set to "any", the pattern
1232 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1233 This doesn't seem right; it now treats the CRLF combination as the line
1234 ending, and so does not match in that case. It's only a pattern such as ^$
1235 that would hit this one: something like ^ABC$ would have failed after \r
1236 and then tried again after \r\n.
1237
1238 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1239 in an attempt to make files that differ only in their line terminators
1240 compare equal. This works on Linux.
1241
1242 17. Under certain error circumstances pcregrep might try to free random memory
1243 as it exited. This is now fixed, thanks to valgrind.
1244
1245 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1246 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1247 was because its rules for how to advance for /g after matching an empty
1248 string at the end of a line did not allow for this case. They now check for
1249 it specially.
1250
1251 20. pcretest is supposed to handle patterns and data of any length, by
1252 extending its buffers when necessary. It was getting this wrong when the
1253 buffer for a data line had to be extended.
1254
1255 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1256 CRLF as a newline sequence.
1257
1258 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1259 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1260 I have nevertheless tidied it up.
1261
1262 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1263
1264 24. Added a man page for pcre-config.
1265
1266
1267 Version 7.0 19-Dec-06
1268 ---------------------
1269
1270 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1271 moving to gcc 4.1.1.
1272
1273 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1274 sys/time.h, which is documented as needed for this function. It doesn't
1275 seem to matter on Linux, but it showed up on some releases of OS X.
1276
1277 3. It seems that there are systems where bytes whose values are greater than
1278 127 match isprint() in the "C" locale. The "C" locale should be the
1279 default when a C program starts up. In most systems, only ASCII printing
1280 characters match isprint(). This difference caused the output from pcretest
1281 to vary, making some of the tests fail. I have changed pcretest so that:
1282
1283 (a) When it is outputting text in the compiled version of a pattern, bytes
1284 other than 32-126 are always shown as hex escapes.
1285
1286 (b) When it is outputting text that is a matched part of a subject string,
1287 it does the same, unless a different locale has been set for the match
1288 (using the /L modifier). In this case, it uses isprint() to decide.
1289
1290 4. Fixed a major bug that caused incorrect computation of the amount of memory
1291 required for a compiled pattern when options that changed within the
1292 pattern affected the logic of the preliminary scan that determines the
1293 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1294 that the computed length was too small. The symptoms of this bug were
1295 either the PCRE error "internal error: code overflow" from pcre_compile(),
1296 or a glibc crash with a message such as "pcretest: free(): invalid next
1297 size (fast)". Examples of patterns that provoked this bug (shown in
1298 pcretest format) are:
1299
1300 /(?-x: )/x
1301 /(?x)(?-x: \s*#\s*)/
1302 /((?i)[\x{c0}])/8
1303 /(?i:[\x{c0}])/8
1304
1305 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1306 is now done differently.
1307
1308 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1309 wrapper classes; (b) implement a new function in the C++ scanner that is
1310 more efficient than the old way of doing things because it avoids levels of
1311 recursion in the regex matching; (c) add a paragraph to the documentation
1312 for the FullMatch() function.
1313
1314 6. The escape sequence \n was being treated as whatever was defined as
1315 "newline". Not only was this contrary to the documentation, which states
1316 that \n is character 10 (hex 0A), but it also went horribly wrong when
1317 "newline" was defined as CRLF. This has been fixed.
1318
1319 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1320 was being set to -1 for the "end of line" case (supposedly a value that no
1321 character can have). Though this value is never used (the check for end of
1322 line is "zero bytes in current character"), it caused compiler complaints.
1323 I've changed it to 0xffffffff.
1324
1325 8. In pcre_version.c, the version string was being built by a sequence of
1326 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1327 string (as it is for production releases) called a macro with an empty
1328 argument. The C standard says the result of this is undefined. The gcc
1329 compiler treats it as an empty string (which was what was wanted) but it is
1330 reported that Visual C gives an error. The source has been hacked around to
1331 avoid this problem.
1332
1333 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1334 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1335 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1336 of them did).
1337
1338 10. Originally, pcretest opened its input and output without "b"; then I was
1339 told that "b" was needed in some environments, so it was added for release
1340 5.0 to both the input and output. (It makes no difference on Unix-like
1341 systems.) Later I was told that it is wrong for the input on Windows. I've
1342 now abstracted the modes into two macros, to make it easier to fiddle with
1343 them, and removed "b" from the input mode under Windows.
1344
1345 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1346
1347 12. Added -help and --help to pcretest as an official way of being reminded
1348 of the options.
1349
1350 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1351 and pcrecpp.cc because they annoy compilers at high warning levels.
1352
1353 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1354
1355 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1356 scripts are not C programs :-) and which was not noticed because it works
1357 on Linux.
1358
1359 16. pcretest is supposed to handle any length of pattern and data line (as one
1360 line or as a continued sequence of lines) by extending its input buffer if
1361 necessary. This feature was broken for very long pattern lines, leading to
1362 a string of junk being passed to pcre_compile() if the pattern was longer
1363 than about 50K.
1364
1365 17. I have done a major re-factoring of the way pcre_compile() computes the
1366 amount of memory needed for a compiled pattern. Previously, there was code
1367 that made a preliminary scan of the pattern in order to do this. That was
1368 OK when PCRE was new, but as the facilities have expanded, it has become
1369 harder and harder to keep it in step with the real compile phase, and there
1370 have been a number of bugs (see for example, 4 above). I have now found a
1371 cunning way of running the real compile function in a "fake" mode that
1372 enables it to compute how much memory it would need, while actually only
1373 ever using a few hundred bytes of working memory and without too many
1374 tests of the mode. This should make future maintenance and development
1375 easier. A side effect of this work is that the limit of 200 on the nesting
1376 depth of parentheses has been removed (though this was never a serious
1377 limitation, I suspect). However, there is a downside: pcre_compile() now
1378 runs more slowly than before (30% or more, depending on the pattern). I
1379 hope this isn't a big issue. There is no effect on runtime performance.
1380
1381 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1382 newline (only possible for the last line of a file) and it was a
1383 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1384
1385 19. Added additional timing features to pcretest. (1) The -tm option now times
1386 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1387 separate command line item, by a number that specifies the number of
1388 repeats to use when timing. The default is 50000; this gives better
1389 precision, but takes uncomfortably long for very large patterns.
1390
1391 20. Extended pcre_study() to be more clever in cases where a branch of a
1392 subpattern has no definite first character. For example, (a*|b*)[cd] would
1393 previously give no result from pcre_study(). Now it recognizes that the
1394 first character must be a, b, c, or d.
1395
1396 21. There was an incorrect error "recursive call could loop indefinitely" if
1397 a subpattern (or the entire pattern) that was being tested for matching an
1398 empty string contained only one non-empty item after a nested subpattern.
1399 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1400 incorrectly, because the \d was being skipped in the check.
1401
1402 22. The pcretest program now has a new pattern option /B and a command line
1403 option -b, which is equivalent to adding /B to every pattern. This causes
1404 it to show the compiled bytecode, without the additional information that
1405 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1406 is the same as /B/I).
1407
1408 23. A new optimization is now able automatically to treat some sequences such
1409 as a*b as a*+b. More specifically, if something simple (such as a character
1410 or a simple class like \d) has an unlimited quantifier, and is followed by
1411 something that cannot possibly match the quantified thing, the quantifier
1412 is automatically "possessified".
1413
1414 24. A recursive reference to a subpattern whose number was greater than 39
1415 went wrong under certain circumstances in UTF-8 mode. This bug could also
1416 have affected the operation of pcre_study().
1417
1418 25. Realized that a little bit of performance could be had by replacing
1419 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1420
1421 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1422
1423 27. Possessive quantifiers such as a++ were previously implemented by turning
1424 them into atomic groups such as ($>a+). Now they have their own opcodes,
1425 which improves performance. This includes the automatically created ones
1426 from 23 above.
1427
1428 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1429 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1430 the first matched character to be a colon. This applied both to named and
1431 numbered groups.
1432
1433 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1434
1435 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1436 building PCRE on Windows easier, so I have included it in the distribution.
1437
1438 31. There is now a check in pcretest against a ridiculously large number being
1439 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1440 loop, the loop is abandoned.
1441
1442 32. Forward references to subpatterns in conditions such as (?(2)...) where
1443 subpattern 2 is defined later cause pcre_compile() to search forwards in
1444 the pattern for the relevant set of parentheses. This search went wrong
1445 when there were unescaped parentheses in a character class, parentheses
1446 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1447
1448 33. "Subroutine" calls and backreferences were previously restricted to
1449 referencing subpatterns earlier in the regex. This restriction has now
1450 been removed.
1451
1452 34. Added a number of extra features that are going to be in Perl 5.10. On the
1453 whole, these are just syntactic alternatives for features that PCRE had
1454 previously implemented using the Python syntax or my own invention. The
1455 other formats are all retained for compatibility.
1456
1457 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1458 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1459 also .NET compatible.
1460
1461 (b) A recursion or subroutine call to a named group can now be defined as
1462 (?&name) as well as (?P>name).
1463
1464 (c) A backreference to a named group can now be defined as \k<name> or
1465 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1466 5.10, are also .NET compatible.
1467
1468 (d) A conditional reference to a named group can now use the syntax
1469 (?(<name>) or (?('name') as well as (?(name).
1470
1471 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1472 groups (named and numbered) that are never evaluated inline, but can be
1473 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1474 is always false. There may be only one alternative in such a group.
1475
1476 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1477 as the simple (?(R). The condition is true only if the most recent
1478 recursion is that of the given number or name. It does not search out
1479 through the entire recursion stack.
1480
1481 (g) The escape \gN or \g{N} has been added, where N is a positive or
1482 negative number, specifying an absolute or relative reference.
1483
1484 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1485 some "unreachable code" warnings.
1486
1487 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1488 things, this adds five new scripts.
1489
1490 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1491 There were also incompatibilities regarding the handling of \Q..\E inside
1492 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1493 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1494
1495 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1496 matches an empty string, and forcibly breaks the loop. There were bugs in
1497 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1498 against aaaa the result was just "a" rather than "aaaa", for example. Two
1499 separate and independent bugs (that affected different cases) have been
1500 fixed.
1501
1502 39. Refactored the code to abolish the use of different opcodes for small
1503 capturing bracket numbers. This is a tidy that I avoided doing when I
1504 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1505 The new approach is not only tidier, it makes it possible to reduce the
1506 memory needed to fix the previous bug (38).
1507
1508 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1509 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1510 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1511 mode.
1512
1513 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1514 report.
1515
1516 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1517 copy construction and assignment in the C++ wrapper.
1518
1519 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1520 couple of bugs that could have given wrong results in the "--newline=crlf"
1521 case.
1522
1523 44. Added a number of casts and did some reorganization of signed/unsigned int
1524 variables following suggestions from Dair Grant. Also renamed the variable
1525 "this" as "item" because it is a C++ keyword.
1526
1527 45. Arranged for dftables to add
1528
1529 #include "pcre_internal.h"
1530
1531 to pcre_chartables.c because without it, gcc 4.x may remove the array
1532 definition from the final binary if PCRE is built into a static library and
1533 dead code stripping is activated.
1534
1535 46. For an unanchored pattern, if a match attempt fails at the start of a
1536 newline sequence, and the newline setting is CRLF or ANY, and the next two
1537 characters are CRLF, advance by two characters instead of one.
1538
1539
1540 Version 6.7 04-Jul-06
1541 ---------------------
1542
1543 1. In order to handle tests when input lines are enormously long, pcretest has
1544 been re-factored so that it automatically extends its buffers when
1545 necessary. The code is crude, but this _is_ just a test program. The
1546 default size has been increased from 32K to 50K.
1547
1548 2. The code in pcre_study() was using the value of the re argument before
1549 testing it for NULL. (Of course, in any sensible call of the function, it
1550 won't be NULL.)
1551
1552 3. The memmove() emulation function in pcre_internal.h, which is used on
1553 systems that lack both memmove() and bcopy() - that is, hardly ever -
1554 was missing a "static" storage class specifier.
1555
1556 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1557 containing an extended class (one that cannot be represented by a bitmap
1558 because it contains high-valued characters or Unicode property items, e.g.
1559 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1560 pattern, but PCRE should not loop if you do not (it no longer does).
1561 [Detail: two cases were found: (a) a repeated subpattern containing an
1562 extended class; (b) a recursive reference to a subpattern that followed a
1563 previous extended class. It wasn't skipping over the extended class
1564 correctly when UTF-8 mode was not set.]
1565
1566 5. A negated single-character class was not being recognized as fixed-length
1567 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1568 compile error "lookbehind assertion is not fixed length".
1569
1570 6. The RunPerlTest auxiliary script was showing an unexpected difference
1571 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1572 write a Perl script that can interpret lines of an input file either as
1573 byte characters or as UTF-8, which is what "perltest" was being required to
1574 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1575 can't do is switch easily at run time between having the "use utf8;" pragma
1576 or not. In the end, I fudged it by using the RunPerlTest script to insert
1577 "use utf8;" explicitly for the UTF-8 tests.
1578
1579 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1580 the end of the subject string, contrary to the documentation and to what
1581 Perl does. This was true of both matching functions. Now it matches only at
1582 the start of the subject and immediately after *internal* newlines.
1583
1584 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1585 a pointer to an int instead of a pointer to an unsigned long int. This
1586 caused problems on 64-bit systems.
1587
1588 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1589 instance of the 'standard' template library not being so standard".
1590
1591 10. There was no check on the number of named subpatterns nor the maximum
1592 length of a subpattern name. The product of these values is used to compute
1593 the size of the memory block for a compiled pattern. By supplying a very
1594 long subpattern name and a large number of named subpatterns, the size
1595 computation could be caused to overflow. This is now prevented by limiting
1596 the length of names to 32 characters, and the number of named subpatterns
1597 to 10,000.
1598
1599 11. Subpatterns that are repeated with specific counts have to be replicated in
1600 the compiled pattern. The size of memory for this was computed from the
1601 length of the subpattern and the repeat count. The latter is limited to
1602 65535, but there was no limit on the former, meaning that integer overflow
1603 could in principle occur. The compiled length of a repeated subpattern is
1604 now limited to 30,000 bytes in order to prevent this.
1605
1606 12. Added the optional facility to have named substrings with the same name.
1607
1608 13. Added the ability to use a named substring as a condition, using the
1609 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1610 are numbers (not recommended). Forward references are permitted.
1611
1612 14. Added forward references in named backreferences (if you see what I mean).
1613
1614 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1615 pattern could run off the end of the subject. For example, the pattern
1616 "(?s)(.{1,5})"8 did this with the subject "ab".
1617
1618 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1619 PCRE_CASELESS was set when matching characters that were quantified with ?
1620 or *.
1621
1622 17. A character class other than a single negated character that had a minimum
1623 but no maximum quantifier - for example [ab]{6,} - was not handled
1624 correctly by pce_dfa_exec(). It would match only one character.
1625
1626 18. A valid (though odd) pattern that looked like a POSIX character
1627 class but used an invalid character after [ (for example [[,abc,]]) caused
1628 pcre_compile() to give the error "Failed: internal error: code overflow" or
1629 in some cases to crash with a glibc free() error. This could even happen if
1630 the pattern terminated after [[ but there just happened to be a sequence of
1631 letters, a binary zero, and a closing ] in the memory that followed.
1632
1633 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1634 over the years. Originally (before any Unicode support), just the bottom 8
1635 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1636 output from "man perlunicode" includes this:
1637
1638 The regular expression compiler produces polymorphic opcodes. That
1639 is, the pattern adapts to the data and automatically switches to
1640 the Unicode character scheme when presented with Unicode data--or
1641 instead uses a traditional byte scheme when presented with byte
1642 data.
1643
1644 Sadly, a wide octal escape does not cause a switch, and in a string with
1645 no other multibyte characters, these octal escapes are treated as before.
1646 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1647 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1648 Unicode string.
1649
1650 I have not perpetrated such confusion in PCRE. Up till now, it took just
1651 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1652 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1653 translate to the appropriate multibyte character.
1654
1655 29. Applied some refactoring to reduce the number of warnings from Microsoft
1656 and Borland compilers. This has included removing the fudge introduced
1657 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1658 a warning about an unused variable.
1659
1660 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1661 characters since release 4.0, because Perl (from release 5.004) does not.
1662 [Or at least, is documented not to: some releases seem to be in conflict
1663 with the documentation.] However, when a pattern was studied with
1664 pcre_study() and all its branches started with \s, PCRE still included VT
1665 as a possible starting character. Of course, this did no harm; it just
1666 caused an unnecessary match attempt.
1667
1668 22. Removed a now-redundant internal flag bit that recorded the fact that case
1669 dependency changed within the pattern. This was once needed for "required
1670 byte" processing, but is no longer used. This recovers a now-scarce options
1671 bit. Also moved the least significant internal flag bit to the most-
1672 significant bit of the word, which was not previously used (hangover from
1673 the days when it was an int rather than a uint) to free up another bit for
1674 the future.
1675
1676 23. Added support for CRLF line endings as well as CR and LF. As well as the
1677 default being selectable at build time, it can now be changed at runtime
1678 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1679 specify that it is scanning data with non-default line endings.
1680
1681 24. Changed the definition of CXXLINK to make it agree with the definition of
1682 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1683
1684 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1685 recursions. This makes a big different to stack usage for some patterns.
1686
1687 26. If a subpattern containing a named recursion or subroutine reference such
1688 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1689 the space required for the compiled pattern went wrong and gave too small a
1690 value. Depending on the environment, this could lead to "Failed: internal
1691 error: code overflow at offset 49" or "glibc detected double free or
1692 corruption" errors.
1693
1694 27. Applied patches from Google (a) to support the new newline modes and (b) to
1695 advance over multibyte UTF-8 characters in GlobalReplace.
1696
1697 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1698 difference for some implementation of PCRE in some Windows version.
1699
1700 29. Added some extra testing facilities to pcretest:
1701
1702 \q<number> in a data line sets the "match limit" value
1703 \Q<number> in a data line sets the "match recursion limt" value
1704 -S <number> sets the stack size, where <number> is in megabytes
1705
1706 The -S option isn't available for Windows.
1707
1708
1709 Version 6.6 06-Feb-06
1710 ---------------------
1711
1712 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1713 in pcreposix.h. I have copied the definition from pcre.h.
1714
1715 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1716 because pcre.h is no longer a built file.
1717
1718 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1719 not normally included in the compiled code.
1720
1721
1722 Version 6.5 01-Feb-06
1723 ---------------------
1724
1725 1. When using the partial match feature with pcre_dfa_exec(), it was not
1726 anchoring the second and subsequent partial matches at the new starting
1727 point. This could lead to incorrect results. For example, with the pattern
1728 /1234/, partially matching against "123" and then "a4" gave a match.
1729
1730 2. Changes to pcregrep:
1731
1732 (a) All non-match returns from pcre_exec() were being treated as failures
1733 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1734 error message is output. Some extra information is given for the
1735 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1736 probably the only errors that are likely to be caused by users (by
1737 specifying a regex that has nested indefinite repeats, for instance).
1738 If there are more than 20 of these errors, pcregrep is abandoned.
1739
1740 (b) A binary zero was treated as data while matching, but terminated the
1741 output line if it was written out. This has been fixed: binary zeroes
1742 are now no different to any other data bytes.
1743
1744 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1745 used to set a locale for matching. The --locale=xxxx long option has
1746 been added (no short equivalent) to specify a locale explicitly on the
1747 pcregrep command, overriding the environment variables.
1748
1749 (d) When -B was used with -n, some line numbers in the output were one less
1750 than they should have been.
1751
1752 (e) Added the -o (--only-matching) option.
1753
1754 (f) If -A or -C was used with -c (count only), some lines of context were
1755 accidentally printed for the final match.
1756
1757 (g) Added the -H (--with-filename) option.
1758
1759 (h) The combination of options -rh failed to suppress file names for files
1760 that were found from directory arguments.
1761
1762 (i) Added the -D (--devices) and -d (--directories) options.
1763
1764 (j) Added the -F (--fixed-strings) option.
1765
1766 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1767
1768 (l) Added the --colo(u)r option.
1769
1770 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1771 is not present by default.
1772
1773 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1774 items such as (?R) or (?1), when the recursion could match a number of
1775 alternatives. If it matched one of the alternatives, but subsequently,
1776 outside the recursion, there was a failure, the code tried to back up into
1777 the recursion. However, because of the way PCRE is implemented, this is not
1778 possible, and the result was an incorrect result from the match.
1779
1780 In order to prevent this happening, the specification of recursion has
1781 been changed so that all such subpatterns are automatically treated as
1782 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1783
1784 4. I had overlooked the fact that, in some locales, there are characters for
1785 which isalpha() is true but neither isupper() nor islower() are true. In
1786 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1787 and ordfeminine) are like this. This affected the treatment of \w and \W
1788 when they appeared in character classes, but not when they appeared outside
1789 a character class. The bit map for "word" characters is now created
1790 separately from the results of isalnum() instead of just taking it from the
1791 upper, lower, and digit maps. (Plus the underscore character, of course.)
1792
1793 5. The above bug also affected the handling of POSIX character classes such as
1794 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1795 permanent tables. Instead, the bit maps for such a class were previously
1796 created as the appropriate unions of the upper, lower, and digit bitmaps.
1797 Now they are created by subtraction from the [[:word:]] class, which has
1798 its own bitmap.
1799
1800 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1801 It is created by subtracting the vertical space characters (\x09, \x0a,
1802 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1803 subtraction was done in the overall bitmap for a character class, meaning
1804 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1805 be recognized. This bug has been fixed.
1806
1807 7. Patches from the folks at Google:
1808
1809 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1810 real life, but is still worth protecting against".
1811
1812 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1813 regular expressions".
1814
1815 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1816 have it.
1817
1818 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1819 "configure" and the latter not, in order to fix a problem somebody had
1820 with compiling the Arg class on HP-UX.
1821
1822 (e) Improve the error-handling of the C++ wrapper a little bit.
1823
1824 (f) New tests for checking recursion limiting.
1825
1826 8. The pcre_memmove() function, which is used only if the environment does not
1827 have a standard memmove() function (and is therefore rarely compiled),
1828 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1829 returning a result (though PCRE never actually uses the result).
1830
1831 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1832 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1833 returned instead of calling malloc() with an overflowing number that would
1834 most likely cause subsequent chaos.
1835
1836 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1837
1838 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1839 with this option is matched, the nmatch and pmatch options of regexec() are
1840 ignored.
1841
1842 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1843 provided in case anyone wants to the the POSIX interface with UTF-8
1844 strings.
1845
1846 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1847 C++ linking (needed for some HP-UX environments).
1848
1849 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1850 (unused parameter) and in the pcre_printint() function (omitted "default"
1851 switch label when the default is to do nothing).
1852
1853 15. Added some code to make it possible, when PCRE is compiled as a C++
1854 library, to replace subject pointers for pcre_exec() with a smart pointer
1855 class, thus making it possible to process discontinuous strings.
1856
1857 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1858 much the same function. They were added by different people who were trying
1859 to make PCRE easy to compile on non-Unix systems. It has been suggested
1860 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1861 for compiling on Windows systems. I have therefore replaced it with
1862 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1863 defaults to "extern" for C or "extern C" for C++, which works fine on
1864 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1865 SCOPE with something explicit in config.h. In addition:
1866
1867 (a) pcreposix.h still had just "extern" instead of either of these macros;
1868 I have replaced it with PCRE_DATA_SCOPE.
1869
1870 (b) Functions such as _pcre_xclass(), which are internal to the library,
1871 but external in the C sense, all had PCRE_EXPORT in their definitions.
1872 This is apparently wrong for the Windows case, so I have removed it.
1873 (It makes no difference on Unix-like systems.)
1874
1875 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1876 of recursive calls to match(). This is different to MATCH_LIMIT because
1877 that limits the total number of calls to match(), not all of which increase
1878 the depth of recursion. Limiting the recursion depth limits the amount of
1879 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1880 when PCRE is compiled, and changed at run time. A patch from Google adds
1881 this functionality to the C++ interface.
1882
1883 18. Changes to the handling of Unicode character properties:
1884
1885 (a) Updated the table to Unicode 4.1.0.
1886
1887 (b) Recognize characters that are not in the table as "Cn" (undefined).
1888
1889 (c) I revised the way the table is implemented to a much improved format
1890 which includes recognition of ranges. It now supports the ranges that
1891 are defined in UnicodeData.txt, and it also amalgamates other
1892 characters into ranges. This has reduced the number of entries in the
1893 table from around 16,000 to around 3,000, thus reducing its size
1894 considerably. I realized I did not need to use a tree structure after
1895 all - a binary chop search is just as efficient. Having reduced the
1896 number of entries, I extended their size from 6 bytes to 8 bytes to
1897 allow for more data.
1898
1899 (d) Added support for Unicode script names via properties such as \p{Han}.
1900
1901 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1902 matching that character.
1903
1904 20. When matching a repeated Unicode property with a minimum greater than zero,
1905 (for example \pL{2,}), PCRE could look past the end of the subject if it
1906 reached it while seeking the minimum number of characters. This could
1907 happen only if some of the characters were more than one byte long, because
1908 there is a check for at least the minimum number of bytes.
1909
1910 21. Refactored the implementation of \p and \P so as to be more general, to
1911 allow for more different types of property in future. This has changed the
1912 compiled form incompatibly. Anybody with saved compiled patterns that use
1913 \p or \P will have to recompile them.
1914
1915 22. Added "Any" and "L&" to the supported property types.
1916
1917 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1918 but give a compile time error if the value is greater than 0xff.
1919
1920 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1921 accidentally not being installed or uninstalled.
1922
1923 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1924 made were to insert the current release number. This seemed silly, because
1925 it made things harder for people building PCRE on systems that don't run
1926 "configure". I have turned pcre.h into a distributed file, no longer built
1927 by "configure", with the version identification directly included. There is
1928 no longer a pcre.h.in file.
1929
1930 However, this change necessitated a change to the pcre-config script as
1931 well. It is built from pcre-config.in, and one of the substitutions was the
1932 release number. I have updated configure.ac so that ./configure now finds
1933 the release number by grepping pcre.h.
1934
1935 26. Added the ability to run the tests under valgrind.
1936
1937
1938 Version 6.4 05-Sep-05
1939 ---------------------
1940
1941 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1942 "--" to be printed when multiple files were scanned, even when none of the
1943 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1944 consider it to be a bug, and have restored the previous behaviour.
1945
1946 2. A couple of code tidies to get rid of compiler warnings.
1947
1948 3. The pcretest program used to cheat by referring to symbols in the library
1949 whose names begin with _pcre_. These are internal symbols that are not
1950 really supposed to be visible externally, and in some environments it is
1951 possible to suppress them. The cheating is now confined to including
1952 certain files from the library's source, which is a bit cleaner.
1953
1954 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1955 file's purpose clearer.
1956
1957 5. Reorganized pcre_ucp_findchar().
1958
1959
1960 Version 6.3 15-Aug-05
1961 ---------------------
1962
1963 1. The file libpcre.pc.in did not have general read permission in the tarball.
1964
1965 2. There were some problems when building without C++ support:
1966
1967 (a) If C++ support was not built, "make install" and "make test" still
1968 tried to test it.
1969
1970 (b) There were problems when the value of CXX was explicitly set. Some
1971 changes have been made to try to fix these, and ...
1972
1973 (c) --disable-cpp can now be used to explicitly disable C++ support.
1974
1975 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1976 backslash in a target when C++ was disabled. This confuses some
1977 versions of "make", apparently. Using an intermediate variable solves
1978 this. (Same for CPP_LOBJ.)
1979
1980 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1981 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1982 necessary on certain architectures.
1983
1984 4. Added a setting of -export-symbols-regex to the link command to remove
1985 those symbols that are exported in the C sense, but actually are local
1986 within the library, and not documented. Their names all begin with
1987 "_pcre_". This is not a perfect job, because (a) we have to except some
1988 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1989 available (and never for static libraries). I have made a note to try to
1990 find a way round (a) in the future.
1991
1992
1993 Version 6.2 01-Aug-05
1994 ---------------------
1995
1996 1. There was no test for integer overflow of quantifier values. A construction
1997 such as {1111111111111111} would give undefined results. What is worse, if
1998 a minimum quantifier for a parenthesized subpattern overflowed and became
1999 negative, the calculation of the memory size went wrong. This could have
2000 led to memory overwriting.
2001
2002 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2003
2004 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2005 operating environments where this matters.
2006
2007 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2008 PCRE options from within the C++ wrapper.
2009
2010 5. Named capturing subpatterns were not being correctly counted when a pattern
2011 was compiled. This caused two problems: (a) If there were more than 100
2012 such subpatterns, the calculation of the memory needed for the whole
2013 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2014 back references of the form \12, where the number was greater than 9, were
2015 not recognized as back references, even though there were sufficient
2016 previous subpatterns.
2017
2018 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2019 versions of gcc, e.g. 2.95.4.
2020
2021
2022 Version 6.1 21-Jun-05
2023 ---------------------
2024
2025 1. There was one reference to the variable "posix" in pcretest.c that was not
2026 surrounded by "#if !defined NOPOSIX".
2027
2028 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2029 the cross-check on the old pcre_info() function, for the benefit of the
2030 cut-down version of PCRE that is currently imported into Exim.
2031
2032 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2033 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2034 patterns that start (?i) but I don't think that matters. The use of (?i) is
2035 just an example; this all applies to the other options as well.
2036
2037 4. Since libtool seems to echo the compile commands it is issuing, the output
2038 from "make" can be reduced a bit by putting "@" in front of each libtool
2039 compile command.
2040
2041 5. Patch from the folks at Google for configure.in to be a bit more thorough
2042 in checking for a suitable C++ installation before trying to compile the
2043 C++ stuff. This should fix a reported problem when a compiler was present,
2044 but no suitable headers.
2045
2046 6. The man pages all had just "PCRE" as their title. I have changed them to
2047 be the relevant file name. I have also arranged that these names are
2048 retained in the file doc/pcre.txt, which is a concatenation in text format
2049 of all the man pages except the little individual ones for each function.
2050
2051 7. The NON-UNIX-USE file had not been updated for the different set of source
2052 files that come with release 6. I also added a few comments about the C++
2053 wrapper.
2054
2055
2056 Version 6.0 07-Jun-05
2057 ---------------------
2058
2059 1. Some minor internal re-organization to help with my DFA experiments.
2060
2061 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2062 didn't matter for the library itself when fully configured, but did matter
2063 when compiling without UCP support, or within Exim, where the ucp files are
2064 not imported.
2065
2066 3. Refactoring of the library code to split up the various functions into
2067 different source modules. The addition of the new DFA matching code (see
2068 below) to a single monolithic source would have made it really too
2069 unwieldy, quite apart from causing all the code to be include in a
2070 statically linked application, when only some functions are used. This is
2071 relevant even without the DFA addition now that patterns can be compiled in
2072 one application and matched in another.
2073
2074 The downside of splitting up is that there have to be some external
2075 functions and data tables that are used internally in different modules of
2076 the library but which are not part of the API. These have all had their
2077 names changed to start with "_pcre_" so that they are unlikely to clash
2078 with other external names.
2079
2080 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2081 a different (DFA) algorithm. Although it is slower than the original
2082 function, it does have some advantages for certain types of matching
2083 problem.
2084
2085 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2086 including restarting after a partial match.
2087
2088 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2089 defined when compiling for Windows was sent to me. I have put it into the
2090 code, though I have no means of testing or verifying it.
2091
2092 7. Added the pcre_refcount() auxiliary function.
2093
2094 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2095 match before or at the first newline in the subject string. In pcretest,
2096 the /f option on a pattern can be used to set this.
2097
2098 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2099 would behave wrongly. This has been present in PCRE since release 4.0.
2100
2101 10. A number of changes to the pcregrep command:
2102
2103 (a) Refactored how -x works; insert ^(...)$ instead of setting
2104 PCRE_ANCHORED and checking the length, in preparation for adding
2105 something similar for -w.
2106
2107 (b) Added the -w (match as a word) option.
2108
2109 (c) Refactored the way lines are read and buffered so as to have more
2110 than one at a time available.
2111
2112 (d) Implemented a pcregrep test script.
2113
2114 (e) Added the -M (multiline match) option. This allows patterns to match
2115 over several lines of the subject. The buffering ensures that at least
2116 8K, or the rest of the document (whichever is the shorter) is available
2117 for matching (and similarly the previous 8K for lookbehind assertions).
2118
2119 (f) Changed the --help output so that it now says
2120
2121 -w, --word-regex(p)
2122
2123 instead of two lines, one with "regex" and the other with "regexp"
2124 because that confused at least one person since the short forms are the
2125 same. (This required a bit of code, as the output is generated
2126 automatically from a table. It wasn't just a text change.)
2127
2128 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2129 option but starts with a hyphen. Could be a pattern or a path name
2130 starting with a hyphen, for instance.
2131
2132 (h) "-" can be given as a file name to represent stdin.
2133
2134 (i) When file names are being printed, "(standard input)" is used for
2135 the standard input, for compatibility with GNU grep. Previously
2136 "<stdin>" was used.
2137
2138 (j) The option --label=xxx can be used to supply a name to be used for
2139 stdin when file names are being printed. There is no short form.
2140
2141 (k) Re-factored the options decoding logic because we are going to add
2142 two more options that take data. Such options can now be given in four
2143 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2144
2145 (l) Added the -A, -B, and -C options for requesting that lines of context
2146 around matches be printed.
2147
2148 (m) Added the -L option to print the names of files that do not contain
2149 any matching lines, that is, the complement of -l.
2150
2151 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2152 continue to scan other files.
2153
2154 (o) The -s option was incorrectly implemented. For compatibility with other
2155 greps, it now suppresses the error message for a non-existent or non-
2156 accessible file (but not the return code). There is a new option called
2157 -q that suppresses the output of matching lines, which was what -s was
2158 previously doing.
2159
2160 (p) Added --include and --exclude options to specify files for inclusion
2161 and exclusion when recursing.
2162
2163 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2164 Hopefully, it now does.
2165
2166 12. Missing cast in pcre_study().
2167
2168 13. Added an "uninstall" target to the makefile.
2169
2170 14. Replaced "extern" in the function prototypes in Makefile.in with
2171 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2172 world, but is set differently for Windows.
2173
2174 15. Added a second compiling function called pcre_compile2(). The only
2175 difference is that it has an extra argument, which is a pointer to an
2176 integer error code. When there is a compile-time failure, this is set
2177 non-zero, in addition to the error test pointer being set to point to an
2178 error message. The new argument may be NULL if no error number is required
2179 (but then you may as well call pcre_compile(), which is now just a
2180 wrapper). This facility is provided because some applications need a
2181 numeric error indication, but it has also enabled me to tidy up the way
2182 compile-time errors are handled in the POSIX wrapper.
2183
2184 16. Added VPATH=.libs to the makefile; this should help when building with one
2185 prefix path and installing with another. (Or so I'm told by someone who
2186 knows more about this stuff than I do.)
2187
2188 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2189 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2190 match everything, including newlines. This is not POSIX-compatible, but
2191 somebody wanted the feature. From pcretest it can be activated by using
2192 both the P and the s flags.
2193
2194 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2195
2196 19. libpcre.pc was being incorrectly installed as executable.
2197
2198 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2199 it now also looks for '\r' so that it will work unmodified on Windows.
2200
2201 21. Added Google's contributed C++ wrapper to the distribution.
2202
2203 22. Added some untidy missing memory free() calls in pcretest, to keep
2204 Electric Fence happy when testing.
2205
2206
2207
2208 Version 5.0 13-Sep-04
2209 ---------------------
2210
2211 1. Internal change: literal characters are no longer packed up into items
2212 containing multiple characters in a single byte-string. Each character
2213 is now matched using a separate opcode. However, there may be more than one
2214 byte in the character in UTF-8 mode.
2215
2216 2. The pcre_callout_block structure has two new fields: pattern_position and
2217 next_item_length. These contain the offset in the pattern to the next match
2218 item, and its length, respectively.
2219
2220 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2221 insertion of callouts before each pattern item. Added the /C option to
2222 pcretest to make use of this.
2223
2224 4. On the advice of a Windows user, the lines
2225
2226 #if defined(_WIN32) || defined(WIN32)
2227 _setmode( _fileno( stdout ), 0x8000 );
2228 #endif /* defined(_WIN32) || defined(WIN32) */
2229
2230 have been added to the source of pcretest. This apparently does useful
2231 magic in relation to line terminators.
2232
2233 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2234 for the benefit of those environments where the "b" makes a difference.
2235
2236 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2237 to know about it. I have put a hack into configure.in that adds in code
2238 to set GCC=yes if CC=icc. This seems to end up at a point in the
2239 generated configure script that is early enough to affect the setting of
2240 compiler options, which is what is needed, but I have no means of testing
2241 whether it really works. (The user who reported this had patched the
2242 generated configure script, which of course I cannot do.)
2243
2244 LATER: After change 22 below (new libtool files), the configure script
2245 seems to know about icc (and also ecc). Therefore, I have commented out
2246 this hack in configure.in.
2247
2248 7. Added support for pkg-config (2 patches were sent in).
2249
2250 8. Negated POSIX character classes that used a combination of internal tables
2251 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2252 [[:^ascii]]. Typically, they would match almost any characters. The other
2253 POSIX classes were not broken in this way.
2254
2255 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2256 to find the match, as PCRE was deluded into thinking that the match had to
2257 start at the start point or following a newline. The same bug applied to
2258 patterns with negative forward assertions or any backward assertions
2259 preceding ".*" at the start, unless the pattern required a fixed first
2260 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2261
2262 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2263 starting at the last subject character, bytes beyond the end of the subject
2264 string were read.
2265
2266 11. Renamed the variable "class" as "classbits" to make life easier for C++
2267 users. (Previously there was a macro definition, but it apparently wasn't
2268 enough.)
2269
2270 12. Added the new field "tables" to the extra data so that tables can be passed
2271 in at exec time, or the internal tables can be re-selected. This allows
2272 a compiled regex to be saved and re-used at a later time by a different
2273 program that might have everything at different addresses.
2274
2275 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2276 -R library as well as a -L library.
2277
2278 14. The debugging options of pcretest (-d on the command line or D on a
2279 pattern) showed incorrect output for anything following an extended class
2280 that contained multibyte characters and which was followed by a quantifier.
2281
2282 15. Added optional support for general category Unicode character properties
2283 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2284 support. It adds about 90K to the size of the library. The meanings of the
2285 inbuilt class escapes such as \d and \s have NOT been changed.
2286
2287 16. Updated pcredemo.c to include calls to free() to release the memory for the
2288 compiled pattern.
2289
2290 17. The generated file chartables.c was being created in the source directory
2291 instead of in the building directory. This caused the build to fail if the
2292 source directory was different from the building directory, and was
2293 read-only.
2294
2295 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2296 file. No doubt somebody will tell me if they don't make sense... Also added
2297 Dan Mooney's comments about building on OpenVMS.
2298
2299 19. Added support for partial matching via the PCRE_PARTIAL option for
2300 pcre_exec() and the \P data escape in pcretest.
2301
2302 20. Extended pcretest with 3 new pattern features:
2303
2304 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2305 write the compiled pattern to the file whose name is "rest-of-line".
2306 This is a straight binary dump of the data, with the saved pointer to
2307 the character tables forced to be NULL. The study data, if any, is
2308 written too. After writing, pcretest reads a new pattern.
2309
2310 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2311 compiled pattern from the given file. There must not be any
2312 occurrences of "<" in the file name (pretty unlikely); if there are,
2313 pcretest will instead treat the initial "<" as a pattern delimiter.
2314 After reading in the pattern, pcretest goes on to read data lines as
2315 usual.
2316
2317 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2318 and 16-bit fields in a compiled pattern, to simulate a pattern that
2319 was compiled on a host of opposite endianness.
2320
2321 21. The pcre-exec() function can now cope with patterns that were compiled on
2322 hosts of opposite endianness, with this restriction:
2323
2324 As for any compiled expression that is saved and used later, the tables
2325 pointer field cannot be preserved; the extra_data field in the arguments
2326 to pcre_exec() should be used to pass in a tables address if a value
2327 other than the default internal tables were used at compile time.
2328
2329 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2330 now diagnosed as an error. Previously, most of the time, a negative number
2331 would have been treated as zero, but if in addition "ovector" was passed as
2332 NULL, a crash could occur.
2333
2334 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2335 new versions from the libtool 1.5 distribution (the last one is a copy of
2336 a file called libtool.m4). This seems to have fixed the need to patch
2337 "configure" to support Darwin 1.3 (which I used to do). However, I still
2338 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2339 workstation).
2340
2341 24. Changed the PCRE licence to be the more standard "BSD" licence.
2342
2343
2344 Version 4.5 01-Dec-03
2345 ---------------------
2346
2347 1. There has been some re-arrangement of the code for the match() function so
2348 that it can be compiled in a version that does not call itself recursively.
2349 Instead, it keeps those local variables that need separate instances for
2350 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2351 needs to "recurse". Keeping track of where control must go is done by means
2352 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2353 hide most of the details from the main code, and operates only if
2354 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2355 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2356 operating.
2357
2358 To make it easier for callers to provide specially tailored get/free
2359 functions for this usage, two new functions, pcre_stack_malloc, and
2360 pcre_stack_free, are used. They are always called in strict stacking order,
2361 and the size of block requested is always the same.
2362
2363 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2364 PCRE has been compiled to use the stack or the heap for recursion. The
2365 -C option of pcretest uses this to show which version is compiled.
2366
2367 A new data escape \S, is added to pcretest; it causes the amounts of store
2368 obtained and freed by both kinds of malloc/free at match time to be added
2369 to the output.
2370
2371 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2372 what's available on my current Linux desktop machine.
2373
2374 3. When matching a UTF-8 string, the test for a valid string at the start has
2375 been extended. If start_offset is not zero, PCRE now checks that it points
2376 to a byte that is the start of a UTF-8 character. If not, it returns
2377 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2378 this is necessary because there may be backward assertions in the pattern.
2379 When matching the same subject several times, it may save resources to use
2380 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2381
2382 4. The code for checking the validity of UTF-8 strings has been tightened so
2383 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2384 containing "overlong sequences".
2385
2386 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2387 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2388 should have been "&", but it just so happened that all the cases this let
2389 through by mistake were picked up later in the function.
2390
2391 6. I had used a variable called "isblank" - this is a C99 function, causing
2392 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2393
2394 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2395 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2396 so the version is shown; (c) stop "make test" echoing "./RunTest".
2397
2398 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2399
2400 9. The prototype for memmove() for systems that don't have it was using
2401 size_t, but the inclusion of the header that defines size_t was later. I've
2402 moved the #includes for the C headers earlier to avoid this.
2403
2404 10. Added some adjustments to the code to make it easier to compiler on certain
2405 special systems:
2406
2407 (a) Some "const" qualifiers were missing.
2408 (b) Added the macro EXPORT before all exported functions; by default this
2409 is defined to be empty.
2410 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2411 that it reads its output file name as an argument instead of writing
2412 to the standard output and assuming this can be redirected.
2413
2414 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2415 class containing characters with values greater than 255, PCRE compilation
2416 went into a loop.
2417
2418 12. A recursive reference to a subpattern that was within another subpattern
2419 that had a minimum quantifier of zero caused PCRE to crash. For example,
2420 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2421 recursion. If the recursively-called subpattern itself had a zero repeat,
2422 that was OK.
2423
2424 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2425 buffer into which it was copied (for escape processing) was still set at
2426 1024, so long lines caused crashes.
2427
2428 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2429 "internal error: code overflow...". This applied to any character class
2430 that was followed by a possessive quantifier.
2431
2432 15. Modified the Makefile to add libpcre.la as a prerequisite for
2433 libpcreposix.la because I was told this is needed for a parallel build to
2434 work.
2435
2436 16. If a pattern that contained .* following optional items at the start was
2437 studied, the wrong optimizing data was generated, leading to matching
2438 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2439 matching string must start with a or b or c. The correct conclusion for
2440 this pattern is that a match can start with any character.
2441
2442
2443 Version 4.4 13-Aug-03
2444 ---------------------
2445
2446 1. In UTF-8 mode, a character class containing characters with values between
2447 127 and 255 was not handled correctly if the compiled pattern was studied.
2448 In fixing this, I have also improved the studying algorithm for such
2449 classes (slightly).
2450
2451 2. Three internal functions had redundant arguments passed to them. Removal
2452 might give a very teeny performance improvement.
2453
2454 3. Documentation bug: the value of the capture_top field in a callout is *one
2455 more than* the number of the hightest numbered captured substring.
2456
2457 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2458 in incorrectly linking with a previously installed version. They now link
2459 explicitly with libpcre.la.
2460
2461 5. configure.in no longer needs to recognize Cygwin specially.
2462
2463 6. A problem in pcre.in for Windows platforms is fixed.
2464
2465 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2466 pcretest, it used to include the size of the study block as part of its
2467 output. Unfortunately, the structure contains a field that has a different
2468 size on different hardware architectures. This meant that the tests that
2469 showed this size failed. As the block is currently always of a fixed size,
2470 this information isn't actually particularly useful in pcretest output, so
2471 I have just removed it.
2472
2473 8. Three pre-processor statements accidentally did not start in column 1.
2474 Sadly, there are *still* compilers around that complain, even though
2475 standard C has not required this for well over a decade. Sigh.
2476
2477 9. In pcretest, the code for checking callouts passed small integers in the
2478 callout_data field, which is a void * field. However, some picky compilers
2479 complained about the casts involved for this on 64-bit systems. Now
2480 pcretest passes the address of the small integer instead, which should get
2481 rid of the warnings.
2482
2483 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2484 both compile and run time, and gives an error if an invalid UTF-8 sequence
2485 is found. There is a option for disabling this check in cases where the
2486 string is known to be correct and/or the maximum performance is wanted.
2487
2488 11. In response to a bug report, I changed one line in Makefile.in from
2489
2490 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2491 to
2492 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2493
2494 to look similar to other lines, but I have no way of telling whether this
2495 is the right thing to do, as I do not use Windows. No doubt I'll get told
2496 if it's wrong...
2497
2498
2499 Version 4.3 21-May-03
2500 ---------------------
2501
2502 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2503 Makefile.
2504
2505 2. Some refactoring to improve the quality of the code:
2506
2507 (i) The utf8_table... variables are now declared "const".
2508
2509 (ii) The code for \cx, which used the "case flipping" table to upper case
2510 lower case letters, now just substracts 32. This is ASCII-specific,
2511 but the whole concept of \cx is ASCII-specific, so it seems
2512 reasonable.
2513
2514 (iii) PCRE was using its character types table to recognize decimal and
2515 hexadecimal digits in the pattern. This is silly, because it handles
2516 only 0-9, a-f, and A-F, but the character types table is locale-
2517 specific, which means strange things might happen. A private
2518 table is now used for this - though it costs 256 bytes, a table is
2519 much faster than multiple explicit tests. Of course, the standard
2520 character types table is still used for matching digits in subject
2521 strings against \d.
2522
2523 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2524 ending in _t are). So I've renamed it as ESC_tee.
2525
2526 3. The first argument for regexec() in the POSIX wrapper should have been
2527 defined as "const".
2528
2529 4. Changed pcretest to use malloc() for its buffers so that they can be
2530 Electric Fenced for debugging.
2531
2532 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2533 to read one or more bytes before the start of the subject string. Often this
2534 had no effect on PCRE's behaviour, but in some circumstances it could
2535 provoke a segmentation fault.
2536
2537 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2538 to try to read one or more bytes before the start of the subject string.
2539
2540 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2541 UTF-8 support could misbehave in various ways if the subject string
2542 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2543 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2544 back over UTF-8 characters.)
2545
2546
2547 Version 4.2 14-Apr-03
2548 ---------------------
2549
2550 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2551
2552 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2553 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2554 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2555 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2556 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2557 and BUILD_EXEEXT
2558 Note: automatic setting of the BUILD variables is not yet working
2559 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2560 compile-time but not at link-time
2561 [LINK]: use for linking executables only
2562 make different versions for Windows and non-Windows
2563 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2564 libraries
2565 [LINK_FOR_BUILD]: new variable
2566 [OBJEXT]: use throughout
2567 [EXEEXT]: use throughout
2568 <winshared>: new target
2569 <wininstall>: new target
2570 <dftables.o>: use native compiler
2571 <dftables>: use native linker
2572 <install>: handle Windows platform correctly
2573 <clean>: ditto
2574 <check>: ditto
2575 copy DLL to top builddir before testing
2576
2577 As part of these changes, -no-undefined was removed again. This was reported
2578 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2579 in any case.
2580
2581 3. Some tidies to get rid of compiler warnings:
2582
2583 . In the match_data structure, match_limit was an unsigned long int, whereas
2584 match_call_count was an int. I've made them both unsigned long ints.
2585
2586 . In pcretest the fact that a const uschar * doesn't automatically cast to
2587 a void * provoked a warning.
2588
2589 . Turning on some more compiler warnings threw up some "shadow" variables
2590 and a few more missing casts.
2591
2592 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2593 option, a class that contained a single character with a value between 128
2594 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2595
2596 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2597 option, a class that contained several characters, but with at least one
2598 whose value was between 128 and 255 caused PCRE to crash.
2599
2600
2601 Version 4.1 12-Mar-03
2602 ---------------------
2603
2604 1. Compiling with gcc -pedantic found a couple of places where casts were
2605 needed, and a string in dftables.c that was longer than standard compilers are
2606 required to support.
2607
2608 2. Compiling with Sun's compiler found a few more places where the code could
2609 be tidied up in order to avoid warnings.
2610
2611 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2612 first of these names is deprecated in the latest Autoconf in favour of the name
2613 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2614 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2615 analogy I have changed it to CFLAGS_FOR_BUILD.
2616
2617 4. Added -no-undefined to the linking command in the Makefile, because this is
2618 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2619 linking step for the pcreposix library.
2620
2621 5. PCRE was failing to diagnose the case of two named groups with the same
2622 name.
2623
2624 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2625 literal character that is needed in the subject for a match, and scans along to
2626 ensure that it is present before embarking on the full matching process. This
2627 saves time in cases of nested unlimited repeats that are never going to match.
2628 Problem: the scan can take a lot of time if the subject is very long (e.g.
2629 megabytes), thus penalizing straightforward matches. It is now done only if the
2630 amount of subject to be scanned is less than 1000 bytes.
2631
2632 7. A lesser problem with the same optimization is that it was recording the
2633 first character of an anchored pattern as "needed", thus provoking a search
2634 right along the subject, even when the first match of the pattern was going to
2635 fail. The "needed" character is now not set for anchored patterns, unless it
2636 follows something in the pattern that is of non-fixed length. Thus, it still
2637 fulfils its original purpose of finding quick non-matches in cases of nested
2638 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2639
2640
2641 Version 4.0 17-Feb-03
2642 ---------------------
2643
2644 1. If a comment in an extended regex that started immediately after a meta-item
2645 extended to the end of string, PCRE compiled incorrect data. This could lead to
2646 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2647
2648 2. Moved to autoconf 2.53 and libtool 1.4.2.
2649
2650 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2651 the special perltest8 script is no longer needed - all the tests can be run
2652 from a single perltest script.
2653
2654 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2655 by \s. It has now been removed in PCRE. This means it isn't recognized as
2656 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2657 class [:space:] *does* include VT, thereby creating a mess.
2658
2659 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2660 space and tab.
2661
2662 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2663 its new features into the main test script, reducing the number of scripts.
2664
2665 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2666 were backward compatible, and made the (?i) apply to the whole pattern, as if
2667 /i were given. Now it behaves more logically, and applies the option setting
2668 only to what follows. PCRE has been changed to follow suit. However, if it
2669 finds options settings right at the start of the pattern, it extracts them into
2670 the global options, as before. Thus, they show up in the info data.
2671
2672 8. Added support for the \Q...\E escape sequence. Characters in between are
2673 treated as literals. This is slightly different from Perl in that $ and @ are
2674 also handled as literals inside the quotes. In Perl, they will cause variable
2675 interpolation. Note the following examples:
2676
2677 Pattern PCRE matches Perl matches
2678
2679 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2680 \Qabc\$xyz\E abc\$xyz abc\$xyz
2681 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2682
2683 For compatibility with Perl, \Q...\E sequences are recognized inside character
2684 classes as well as outside them.
2685
2686 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2687 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2688 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2689 signed/unsigned warnings.
2690
2691 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2692 option for pcretest, so I've replaced it by a simple function that does just
2693 that job.
2694
2695 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2696 "pcregrep -".
2697
2698 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2699 Java package. This provides some syntactic sugar for simple cases of what my
2700 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2701 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2702 item, you can use this simplified notation. Note that only makes sense with
2703 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2704 greediness, whatever the setting of the PCRE_UNGREEDY option.
2705
2706 13. A change of greediness default within a pattern was not taking effect at
2707 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2708 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2709 was abstracted outside.
2710
2711 14. PCRE now supports the \G assertion. It is true when the current matching
2712 position is at the start point of the match. This differs from \A when the
2713 starting offset is non-zero. Used with the /g option of pcretest (or similar
2714 code), it works in the same way as it does for Perl's /g option. If all
2715 alternatives of a regex begin with \G, the expression is anchored to the start
2716 match position, and the "anchored" flag is set in the compiled expression.
2717
2718 15. Some bugs concerning the handling of certain option changes within patterns
2719 have been fixed. These applied to options other than (?ims). For example,
2720 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2721 been the other way round. Some of this was related to change 7 above.
2722
2723 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2724 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2725 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2726 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2727
2728 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2729 mode. Unlike ".", it always matches newline, whatever the setting of
2730 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2731 assertions. Perl allows it, but it doesn't (in general) work because it can't
2732 calculate the length of the lookbehind. At least, that's the case for Perl
2733 5.8.0 - I've been told they are going to document that it doesn't work in
2734 future.
2735
2736 18. Added an error diagnosis for escapes that PCRE does not support: these are
2737 \L, \l, \N, \P, \p, \U, \u, and \X.
2738
2739 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2740 reading past the end of the pattern in cases such as /[abcd/.
2741
2742 20. PCRE was getting more memory than necessary for patterns with classes that
2743 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2744
2745 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2746 compiling PCRE for use with Virtual Pascal.
2747
2748 22. Small fix to the Makefile to make it work properly if the build is done
2749 outside the source tree.
2750
2751 23. Added a new extension: a condition to go with recursion. If a conditional
2752 subpattern starts with (?(R) the "true" branch is used if recursion has
2753 happened, whereas the "false" branch is used only at the top level.
2754
2755 24. When there was a very long string of literal characters (over 255 bytes
2756 without UTF support, over 250 bytes with UTF support), the computation of how
2757 much memory was required could be incorrect, leading to segfaults or other
2758 strange effects.
2759
2760 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2761 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2762 there was a subsequent back reference to those brackets. This meant that, for
2763 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2764 possible to check for precisely this case. All we can do is abandon the
2765 optimization if .* occurs inside capturing brackets when there are any back
2766 references whatsoever. (See below for a better fix that came later.)
2767
2768 26. The handling of the optimization for finding the first character of a
2769 non-anchored pattern, and for finding a character that is required later in the
2770 match were failing in some cases. This didn't break the matching; it just
2771 failed to optimize when it could. The way this is done has been re-implemented.
2772
2773 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2774
2775 28. Added a new feature that provides some of the functionality that Perl
2776 provides with (?{...}). The facility is termed a "callout". The way it is done
2777 in PCRE is for the caller to provide an optional function, by setting
2778 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2779 global variable. By default it is unset, which disables all calling out. To get
2780 the function called, the regex must include (?C) at appropriate points. This
2781 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2782 This provides a means of identifying different callout points. When PCRE
2783 reaches such a point in the regex, if pcre_callout has been set, the external
2784 function is called. It is provided with data in a structure called
2785 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2786 matching continues; if it returns a non-zero value, the match at the current
2787 point fails. However, backtracking will occur if possible. [This was changed
2788 later and other features added - see item 49 below.]
2789
2790 29. pcretest is upgraded to test the callout functionality. It provides a
2791 callout function that displays information. By default, it shows the start of
2792 the match and the current position in the text. There are some new data escapes
2793 to vary what happens:
2794
2795 \C+ in addition, show current contents of captured substrings
2796 \C- do not supply a callout function
2797 \C!n return 1 when callout number n is reached
2798 \C!n!m return 1 when callout number n is reached for the mth time
2799
2800 30. If pcregrep was called with the -l option and just a single file name, it
2801 output "<stdin>" if a match was found, instead of the file name.
2802
2803 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2804 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2805 pcre_exec(). This saves a malloc/free per call. The default value of
2806 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2807 when configuring.
2808
2809 32. The default maximum size of a compiled pattern is 64K. There have been a
2810 few cases of people hitting this limit. The code now uses macros to handle the
2811 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2812 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2813 configuring. Tests 2 and 5 work only with 2-byte links because they output
2814 debugging information about compiled patterns.
2815
2816 33. Internal code re-arrangements:
2817
2818 (a) Moved the debugging function for printing out a compiled regex into
2819 its own source file (printint.c) and used #include to pull it into
2820 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2821 separate copies.
2822
2823 (b) Defined the list of op-code names for debugging as a macro in
2824 internal.h so that it is next to the definition of the opcodes.
2825
2826 (c) Defined a table of op-code lengths for simpler skipping along compiled
2827 code. This is again a macro in internal.h so that it is next to the
2828 definition of the opcodes.
2829
2830 34. Added support for recursive calls to individual subpatterns, along the
2831 lines of Robin Houston's patch (but implemented somewhat differently).
2832
2833 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2834 allow it to read and process whole directories in Win32. This code was
2835 contributed by Lionel Fourquaux; it has not been tested by me.
2836
2837 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2838 used to name a group. Names consist of alphanumerics and underscores, and must
2839 be unique. Back references use the syntax (?P=name) and recursive calls use
2840 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2841 numbers. The function pcre_fullinfo() can be used after compilation to extract
2842 a name/number map. There are three relevant calls:
2843
2844 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2845 PCRE_INFO_NAMECOUNT yields the number of entries
2846 PCRE_INFO_NAMETABLE yields a pointer to the map.
2847
2848 The map is a vector of fixed-size entries. The size of each entry depends on
2849 the length of the longest name used. The first two bytes of each entry are the
2850 group number, most significant byte first. There follows the corresponding
2851 name, zero terminated. The names are in alphabetical order.
2852
2853 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2854 case instead of 255. Making it the same both with and without UTF-8 support
2855 means that the same test output works with both.
2856
2857 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2858 calling malloc() with a zero argument.
2859
2860 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2861 optimization. I've improved things by keeping a bitmap of backreferences with
2862 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2863 fact referenced, the optimization can be applied. It is unlikely that a
2864 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2865 the match to follow \n) will appear inside brackets with a number greater than
2866 31, but if it does, any back reference > 31 suppresses the optimization.
2867
2868 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2869 of disabling numbered capturing parentheses. Any opening parenthesis that is
2870 not followed by ? behaves as if it were followed by ?: but named parentheses
2871 can still be used for capturing (and they will acquire numbers in the usual
2872 way).
2873
2874 41. Redesigned the return codes from the match() function into yes/no/error so
2875 that errors can be passed back from deep inside the nested calls. A malloc
2876 failure while inside a recursive subpattern call now causes the
2877 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2878
2879 42. It is now possible to set a limit on the number of times the match()
2880 function is called in a call to pcre_exec(). This facility makes it possible to
2881 limit the amount of recursion and backtracking, though not in a directly
2882 obvious way, because the match() function is used in a number of different
2883 circumstances. The count starts from zero for each position in the subject
2884 string (for non-anchored patterns). The default limit is, for compatibility, a
2885 large number, namely 10 000 000. You can change this in two ways:
2886
2887 (a) When configuring PCRE before making, you can use --with-match-limit=n
2888 to set a default value for the compiled library.
2889
2890 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2891 a different value is set. See 45 below.
2892
2893 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2894
2895 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2896 of things that can be changed at compile time. The first argument specifies
2897 what is wanted and the second points to where the information is to be placed.
2898 The current list of available information is:
2899
2900 PCRE_CONFIG_UTF8
2901
2902 The output is an integer that is set to one if UTF-8 support is available;
2903 otherwise it is set to zero.
2904
2905 PCRE_CONFIG_NEWLINE
2906
2907 The output is an integer that it set to the value of the code that is used for
2908 newline. It is either LF (10) or CR (13).
2909
2910 PCRE_CONFIG_LINK_SIZE
2911
2912 The output is an integer that contains the number of bytes used for internal
2913 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2914
2915 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2916
2917 The output is an integer that contains the threshold above which the POSIX
2918 interface uses malloc() for output vectors. See item 31 above.
2919
2920 PCRE_CONFIG_MATCH_LIMIT
2921
2922 The output is an unsigned integer that contains the default limit of the number
2923 of match() calls in a pcre_exec() execution. See 42 above.
2924
2925 44. pcretest has been upgraded by the addition of the -C option. This causes it
2926 to extract all the available output from the new pcre_config() function, and to
2927 output it. The program then exits immediately.
2928
2929 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2930 order to support additional features. One way would have been to define
2931 pcre_exec2() (for example) with extra arguments, but this would not have been
2932 extensible, and would also have required all calls to the original function to
2933 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2934 is used for passing in "extra" data from pcre_study().
2935
2936 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2937 contains the following fields:
2938
2939 flags a bitmap indicating which of the following fields are set
2940 study_data opaque data from pcre_study()
2941 match_limit a way of specifying a limit on match() calls for a specific
2942 call to pcre_exec()
2943 callout_data data for callouts (see 49 below)
2944
2945 The flag bits are also defined in pcre.h, and are
2946
2947 PCRE_EXTRA_STUDY_DATA
2948 PCRE_EXTRA_MATCH_LIMIT
2949 PCRE_EXTRA_CALLOUT_DATA
2950
2951 The pcre_study() function now returns one of these new pcre_extra blocks, with
2952 the actual study data pointed to by the study_data field, and the
2953 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2954 before. That is, this change is entirely upwards-compatible and requires no
2955 change to existing code.
2956
2957 If you want to pass in additional data to pcre_exec(), you can either place it
2958 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2959 block.
2960
2961 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2962 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2963 times with different match limits, until it finds the minimum value needed for
2964 pcre_exec() to complete. The value is then output. This can be instructive; for
2965 most simple matches the number is quite small, but for pathological cases it
2966 gets very large very quickly.
2967
2968 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2969 returns the size of the data block pointed to by the study_data field in a
2970 pcre_extra block, that is, the value that was passed as the argument to
2971 pcre_malloc() when PCRE was getting memory in which to place the information
2972 created by pcre_study(). The fourth argument should point to a size_t variable.
2973 pcretest has been extended so that this information is shown after a successful
2974 pcre_study() call when information about the compiled regex is being displayed.
2975
2976 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2977 because what follows is always an absolute path. (Later: it turns out that this
2978 is more than cosmetic for MinGW, because it doesn't like empty path
2979 components.)
2980
2981 49. Some changes have been made to the callout feature (see 28 above):
2982
2983 (i) A callout function now has three choices for what it returns:
2984
2985 0 => success, carry on matching
2986 > 0 => failure at this point, but backtrack if possible
2987 < 0 => serious error, return this value from pcre_exec()
2988
2989 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2990 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2991 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2992 use by callout functions. It will never be used by PCRE itself.
2993
2994 (ii) The pcre_extra structure (see 45 above) has a void * field called
2995 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2996 pcre_callout_block structure has a field of the same name. The contents of
2997 the field passed in the pcre_extra structure are passed to the callout
2998 function in the corresponding field in the callout block. This makes it
2999 easier to use the same callout-containing regex from multiple threads. For
3000 testing, the pcretest program has a new data escape
3001
3002 \C*n pass the number n (may be negative) as callout_data
3003
3004 If the callout function in pcretest receives a non-zero value as
3005 callout_data, it returns that value.
3006
3007 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3008 there were some redundant $(CFLAGS) in commands that are now specified as
3009 $(LINK), which already includes $(CFLAGS).
3010
3011 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3012 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3013 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3014 one-byte characters throughout. Note that case-insensitive matching applies
3015 only to characters whose values are less than 256. PCRE doesn't support the
3016 notion of cases for higher-valued characters.
3017
3018 (i) A character class whose characters are all within 0-255 is handled as
3019 a bit map, and the map is inverted for negative classes. Previously, a
3020 character > 255 always failed to match such a class; however it should
3021 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3022
3023 (ii) A negated character class with a single character < 255 is coded as
3024 "not this character" (OP_NOT). This wasn't working properly when the test
3025 character was multibyte, either singly or repeated.
3026
3027 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3028 mode, for example: \x{100}{2,3}.
3029
3030 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3031 singly or repeated) now correctly test multibyte characters. However,
3032 PCRE doesn't recognize any characters with values greater than 255 as
3033 digits, spaces, or word characters. Such characters always match \D, \S,
3034 and \W, and never match \d, \s, or \w.
3035
3036 (v) Classes may now contain characters and character ranges with values
3037 greater than 255. For example: [ab\x{100}-\x{400}].
3038
3039 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3040 PCRE in UTF-8 mode.
3041
3042 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3043 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3044 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3045 value.)
3046
3047 53. The single man page has become too large. I have therefore split it up into
3048 a number of separate man pages. These also give rise to individual HTML pages;
3049 these are now put in a separate directory, and there is an index.html page that
3050 lists them all. Some hyperlinking between the pages has been installed.
3051
3052 54. Added convenience functions for handling named capturing parentheses.
3053
3054 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3055 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3056 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3057 are faulted.
3058
3059 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3060 calling configure. These values are used when compiling the dftables.c program
3061 which is run to generate the source of the default character tables. They
3062 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3063 you will need to set these values.
3064
3065 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3066
3067
3068 Version 3.9 02-Jan-02
3069 ---------------------
3070
3071 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3072
3073 2. If --disable-static was given, the building process failed when trying to
3074 build pcretest and pcregrep. (For some reason it was using libtool to compile
3075 them, which is not right, as they aren't part of the library.)
3076
3077
3078 Version 3.8 18-Dec-01
3079 ---------------------
3080
3081 1. The experimental UTF-8 code was completely screwed up. It was packing the
3082 bytes in the wrong order. How dumb can you get?
3083
3084
3085 Version 3.7 29-Oct-01
3086 ---------------------
3087
3088 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3089 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3090 this didn't happen under Solaris 8, where I normally test things.
3091
3092 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3093 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3094 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3095 this fix an hour or so after the initial 3.7 release.)
3096
3097
3098 Version 3.6 23-Oct-01
3099 ---------------------
3100
3101 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3102 offsets passed as NULL with zero offset count.
3103
3104 2. The config.guess and config.sub files had not been updated when I moved to
3105 the latest autoconf.
3106
3107
3108 Version 3.5 15-Aug-01
3109 ---------------------
3110
3111 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3112 had been forgotten.
3113
3114 2. By using declared but undefined structures, we can avoid using "void"
3115 definitions in pcre.h while keeping the internal definitions of the structures
3116 private.
3117
3118 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3119 user point of view, this means that both static and shared libraries are built
3120 by default, but this can be individually controlled. More of the work of
3121 handling this static/shared cases is now inside libtool instead of PCRE's make
3122 file.
3123
3124 4. The pcretest utility is now installed along with pcregrep because it is
3125 useful for users (to test regexs) and by doing this, it automatically gets
3126 relinked by libtool. The documentation has been turned into a man page, so
3127 there are now .1, .txt, and .html versions in /doc.
3128
3129 5. Upgrades to pcregrep:
3130 (i) Added long-form option names like gnu grep.
3131 (ii) Added --help to list all options with an explanatory phrase.
3132 (iii) Added -r, --recursive to recurse into sub-directories.
3133 (iv) Added -f, --file to read patterns from a file.
3134
3135 6. pcre_exec() was referring to its "code" argument before testing that
3136 argument for NULL (and giving an error if it was NULL).
3137
3138 7. Upgraded Makefile.in to allow for compiling in a different directory from
3139 the source directory.
3140
3141 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3142 options bits, the pointer it was passed was to an int instead of to an unsigned
3143 long int. This mattered only on 64-bit systems.
3144
3145 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3146 generated) instead of pcre.in, which it its source. Also made the same change
3147 in several of the .c files.
3148
3149 10. A new release of gcc defines printf() as a macro, which broke pcretest
3150 because it had an ifdef in the middle of a string argument for printf(). Fixed
3151 by using separate calls to printf().
3152
3153 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3154 script, to force use of CR or LF instead of \n in the source. On non-Unix
3155 systems, the value can be set in config.h.
3156
3157 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3158 absolute limit. Changed the text of the error message to make this clear, and
3159 likewise updated the man page.
3160
3161 13. The limit of 99 on the number of capturing subpatterns has been removed.
3162 The new limit is 65535, which I hope will not be a "real" limit.
3163
3164
3165 Version 3.4 22-Aug-00
3166 ---------------------
3167
3168 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3169
3170 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3171
3172
3173 Version 3.3 01-Aug-00
3174 ---------------------
3175
3176 1. If an octal character was given, but the value was greater than \377, it
3177 was not getting masked to the least significant bits, as documented. This could
3178 lead to crashes in some systems.
3179
3180 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3181 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3182
3183 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3184 These just pass their arguments on to (pcre_free)(), but they are provided
3185 because some uses of PCRE bind it to non-C systems that can call its functions,
3186 but cannot call free() or pcre_free() directly.
3187
3188 4. Add "make test" as a synonym for "make check". Corrected some comments in
3189 the Makefile.
3190
3191 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3192 Makefile.
3193
3194 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3195 command called pgrep for grepping around the active processes.
3196
3197 7. Added the beginnings of support for UTF-8 character strings.
3198
3199 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3200 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3201 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3202 out for the ar command.)
3203
3204
3205 Version 3.2 12-May-00
3206 ---------------------
3207
3208 This is purely a bug fixing release.
3209
3210 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3211 of ZA. This was just one example of several cases that could provoke this bug,
3212 which was introduced by change 9 of version 2.00. The code for breaking
3213 infinite loops after an iteration that matches an empty string was't working
3214 correctly.
3215
3216 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3217 when matched against abbab (for example). After matching an empty string, it
3218 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3219 caused it to match further down the string than it should.
3220
3221 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3222 was there because it doesn't seem to be needed, and it causes trouble on some
3223 systems, as it is not a Standard C header. It has been removed.
3224
3225 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3226 were reported on the Macintosh. The changes were from
3227
3228 while ((c = *(++ptr)) != 0 && c != '\n');
3229 to
3230 while ((c = *(++ptr)) != 0 && c != '\n') ;
3231
3232 Totally extraordinary, but if that's what it takes...
3233
3234 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3235 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3236 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3237 assumes the way PCRE uses memmove() (always moving upwards).
3238
3239 6. PCRE is being used in one environment where strchr() is not available. There
3240 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3241 faster code anyway.
3242
3243
3244 Version 3.1 09-Feb-00
3245 ---------------------
3246
3247 The only change in this release is the fixing of some bugs in Makefile.in for
3248 the "install" target:
3249
3250 (1) It was failing to install pcreposix.h.
3251
3252 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3253
3254
3255 Version 3.0 01-Feb-00
3256 ---------------------
3257
3258 1. Add support for the /+ modifier to perltest (to output $` like it does in
3259 pcretest).
3260
3261 2. Add support for the /g modifier to perltest.
3262
3263 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3264 matches null strings.
3265
3266 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3267 pattern. Perl treats empty patterns specially - it reuses the most recent
3268 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3269 effect.
3270
3271 5. The POSIX interface was broken in that it was just handing over the POSIX
3272 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3273 required a bigger vector, with some working space on the end. This means that
3274 the POSIX wrapper now has to get and free some memory, and copy the results.
3275
3276 6. Added some simple autoconf support, placing the test data and the
3277 documentation in separate directories, re-organizing some of the
3278 information files, and making it build pcre-config (a GNU standard). Also added
3279 libtool support for building PCRE as a shared library, which is now the
3280 default.
3281
3282 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3283 09 are not valid octal constants. Single digits will be used for minor values
3284 less than 10.
3285
3286 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3287 existing programs that set these in the POSIX interface can use PCRE without
3288 modification.
3289
3290 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3291 return all that pcre_info() returns, plus additional data. The pcre_info()
3292 function is retained for compatibility, but is considered to be obsolete.
3293
3294 10. Added experimental recursion feature (?R) to handle one common case that
3295 Perl 5.6 will be able to do with (?p{...}).
3296
3297 11. Added support for POSIX character classes like [:alpha:], which Perl is
3298 adopting.
3299
3300
3301 Version 2.08 31-Aug-99
3302 ----------------------
3303
3304 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3305 trying to match at the startoffset position, but instead was moving forward to
3306 the next newline as if a previous match had failed.
3307
3308 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3309 and could get into a loop if a null string was matched other than at the start
3310 of the subject.
3311
3312 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3313 be distinguished at compile time, and for completeness also added PCRE_DATE.
3314
3315 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3316 in GnuWin32 environments.
3317
3318
3319 Version 2.07 29-Jul-99
3320 ----------------------
3321
3322 1. The documentation is now supplied in plain text form and HTML as well as in
3323 the form of man page sources.
3324
3325 2. C++ compilers don't like assigning (void *) values to other pointer types.
3326 In particular this affects malloc(). Although there is no problem in Standard
3327 C, I've put in casts to keep C++ compilers happy.
3328
3329 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3330 should be (const char *).
3331
3332 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3333 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3334 However, I haven't made this a standard facility. The documentation doesn't
3335 mention it, and the Makefile doesn't support it.
3336
3337 5. The Makefile now contains an "install" target, with editable destinations at
3338 the top of the file. The pcretest program is not installed.
3339
3340 6. pgrep -V now gives the PCRE version number and date.
3341
3342 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3343 causing the entire string to be ignored, instead of just the last character.
3344
3345 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3346 non-matching string, it can take a very, very long time, even for strings of
3347 quite modest length, because of the nested recursion. PCRE now does better in
3348 some of these cases. It does this by remembering the last required literal
3349 character in the pattern, and pre-searching the subject to ensure it is present
3350 before running the real match. In other words, it applies a heuristic to detect
3351 some types of certain failure quickly, and in the above example, if presented
3352 with a string that has no trailing " it gives "no match" very quickly.
3353
3354 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3355 other alternatives are tried instead.
3356
3357
3358 Version 2.06 09-Jun-99
3359 ----------------------
3360
3361 1. Change pcretest's output for amount of store used to show just the code
3362 space, because the remainder (the data block) varies in size between 32-bit and
3363 64-bit systems.
3364
3365 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3366 start matching at. This allows lookbehinds to work when searching for multiple
3367 occurrences in a string.
3368
3369 3. Added additional options to pcretest for testing multiple occurrences:
3370
3371 /+ outputs the rest of the string that follows a match
3372 /g loops for multiple occurrences, using the new startoffset argument
3373 /G loops for multiple occurrences by passing an incremented pointer
3374
3375 4. PCRE wasn't doing the "first character" optimization for patterns starting
3376 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3377 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3378 the letter 'x'. On long subject strings, this gives a significant speed-up.
3379
3380
3381 Version 2.05 21-Apr-99
3382 ----------------------
3383
3384 1. Changed the type of magic_number from int to long int so that it works
3385 properly on 16-bit systems.
3386
3387 2. Fixed a bug which caused patterns starting with .* not to work correctly
3388 when the subject string contained newline characters. PCRE was assuming
3389 anchoring for such patterns in all cases, which is not correct because .* will
3390 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3391 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3392 must be retried after every newline in the subject.
3393
3394
3395 Version 2.04 18-Feb-99
3396 ----------------------
3397
3398 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3399 computation of the store needed to hold the pattern was incorrect (too large).
3400 If such patterns were nested a few deep, this could multiply and become a real
3401 problem.
3402
3403 2. Added /M option to pcretest to show the memory requirement of a specific
3404 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3405
3406 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3407 compiled in such a way that the backtracking after subsequent failure was
3408 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3409 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3410
3411
3412 Version 2.03 02-Feb-99
3413 ----------------------
3414
3415 1. Fixed typo and small mistake in man page.
3416
3417 2. Added 4th condition (GPL supersedes if conflict) and created separate
3418 LICENCE file containing the conditions.
3419
3420 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3421 Perl, that is the internal \ allows the delimiter to be included in the
3422 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3423 the final delimiter, add \ to the end of the pattern (to test the error).
3424
3425 4. Added the convenience functions for extracting substrings after a successful
3426 match. Updated pcretest to make it able to test these functions.
3427
3428
3429 Version 2.02 14-Jan-99
3430 ----------------------
3431
3432 1. Initialized the working variables associated with each extraction so that
3433 their saving and restoring doesn't refer to uninitialized store.
3434
3435 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3436 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3437 fix the problem.
3438
3439 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3440 calls, and wasn't printing the correct value for compiling calls. Increased the
3441 default value of LOOPREPEAT, and the number of significant figures in the
3442 times.
3443
3444 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3445
3446 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3447 a building problem on Windows NT with a FAT file system.
3448
3449
3450 Version 2.01 21-Oct-98
3451 ----------------------
3452
3453 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3454 to character tables built by pcre_maketables() in the current locale. If NULL
3455 is passed, the default tables are used.
3456
3457
3458 Version 2.00 24-Sep-98
3459 ----------------------
3460
3461 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3462 it any more.
3463
3464 2. Allow quantification of (?>) groups, and make it work correctly.
3465
3466 3. The first character computation wasn't working for (?>) groups.
3467
3468 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3469 end of the subject) and add 5.005's \z, which really does match only at the
3470 very end of the subject.
3471
3472 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3473
3474 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3475 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3476 localized options. All options to pcre_study() were also removed.
3477
3478 7. Add other new features from 5.005:
3479
3480 $(?<= positive lookbehind
3481 $(?<! negative lookbehind
3482 (?imsx-imsx) added the unsetting capability
3483 such a setting is global if at outer level; local otherwise
3484 (?imsx-imsx:) non-capturing groups with option setting
3485 (?(cond)re|re) conditional pattern matching
3486
3487 A backreference to itself in a repeated group matches the previous
3488 captured string.
3489
3490 8. General tidying up of studying (both automatic and via "study")
3491 consequential on the addition of new assertions.
3492
3493 9. As in 5.005, unlimited repeated groups that could match an empty substring
3494 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3495 runtime if any iteration does actually match an empty substring.
3496
3497 10. Include the RunTest script in the distribution.
3498
3499 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3500 discrepancies, some of which were old and were also with respect to 5.004. They
3501 have now been fixed.
3502
3503
3504 Version 1.09 28-Apr-98
3505 ----------------------
3506
3507 1. A negated single character class followed by a quantifier with a minimum
3508 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3509 program crashes, or just wrong answers. This did not apply to negated classes
3510 containing more than one character, or to minima other than one.
3511
3512
3513 Version 1.08 27-Mar-98
3514 ----------------------
3515
3516 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3517
3518 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3519 latter must appear before anything that relies on it in the pattern.
3520
3521
3522 Version 1.07 16-Feb-98
3523 ----------------------
3524
3525 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3526 repeat of a potentially empty string).
3527
3528
3529 Version 1.06 23-Jan-98
3530 ----------------------
3531
3532 1. Added Markus Oberhumer's little patches for C++.
3533
3534 2. Literal strings longer than 255 characters were broken.
3535
3536
3537 Version 1.05 23-Dec-97
3538 ----------------------
3539
3540 1. Negated character classes containing more than one character were failing if
3541 PCRE_CASELESS was set at run time.
3542
3543
3544 Version 1.04 19-Dec-97
3545 ----------------------
3546
3547 1. Corrected the man page, where some "const" qualifiers had been omitted.
3548
3549 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3550 input syntax.
3551
3552 3. Fixed memory leak which occurred when a regex with back references was
3553 matched with an offsets vector that wasn't big enough. The temporary memory
3554 that is used in this case wasn't being freed if the match failed.
3555
3556 4. Tidied pcretest to ensure it frees memory that it gets.
3557
3558 5. Temporary memory was being obtained in the case where the passed offsets
3559 vector was exactly big enough.
3560
3561 6. Corrected definition of offsetof() from change 5 below.
3562
3563 7. I had screwed up change 6 below and broken the rules for the use of
3564 setjmp(). Now fixed.
3565
3566
3567 Version 1.03 18-Dec-97
3568 ----------------------
3569
3570 1. A erroneous regex with a missing opening parenthesis was correctly
3571 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3572 on some systems.
3573
3574 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3575 it was reported that one broken compiler failed on the former because "code" is
3576 also an independent variable.
3577
3578 3. The erroneous regex a[]b caused an array overrun reference.
3579
3580 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3581 fail on data ending with that character. (It was going on too far, and checking
3582 the next character, typically a binary zero.) This was specific to the
3583 optimized code for single-character negative classes.
3584
3585 5. Added a contributed patch from the TIN world which does the following:
3586
3587 + Add an undef for memmove, in case the the system defines a macro for it.
3588
3589 + Add a definition of offsetof(), in case there isn't one. (I don't know
3590 the reason behind this - offsetof() is part of the ANSI standard - but
3591 it does no harm).
3592
3593 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3594 most of the places where whitespace preceded '#'. I have given up and
3595 allowed the remaining 2 cases to be at the margin.
3596
3597 + Rename some variables in pcre to eliminate shadowing. This seems very
3598 pedantic, but does no harm, of course.
3599
3600 6. Moved the call to setjmp() into its own function, to get rid of warnings
3601 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3602
3603 7. Constructs such as \d{8,} were compiling into the equivalent of
3604 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3605 outcome, but in this particular case used more store than had been allocated,
3606 which caused the bug to be discovered because it threw up an internal error.
3607
3608 8. The debugging code in both pcre and pcretest for outputting the compiled
3609 form of a regex was going wrong in the case of back references followed by
3610 curly-bracketed repeats.
3611
3612
3613 Version 1.02 12-Dec-97
3614 ----------------------
3615
3616 1. Typos in pcre.3 and comments in the source fixed.
3617
3618 2. Applied a contributed patch to get rid of places where it used to remove
3619 'const' from variables, and fixed some signed/unsigned and uninitialized
3620 variable warnings.
3621
3622 3. Added the "runtest" target to Makefile.
3623
3624 4. Set default compiler flag to -O2 rather than just -O.
3625
3626
3627 Version 1.01 19-Nov-97
3628 ----------------------
3629
3630 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3631 like /([ab]*)*/, that is, for classes with more than one character in them.
3632
3633 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3634 as /((?>a*))*/ (a PCRE_EXTRA facility).
3635
3636
3637 Version 1.00 18-Nov-97
3638 ----------------------
3639
3640 1. Added compile-time macros to support systems such as SunOS4 which don't have
3641 memmove() or strerror() but have other things that can be used instead.
3642
3643 2. Arranged that "make clean" removes the executables.
3644
3645
3646 Version 0.99 27-Oct-97
3647 ----------------------
3648
3649 1. Fixed bug in code for optimizing classes with only one character. It was
3650 initializing a 32-byte map regardless, which could cause it to run off the end
3651 of the memory it had got.
3652
3653 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3654
3655
3656 Version 0.98 22-Oct-97
3657 ----------------------
3658
3659 1. Fixed bug in code for handling temporary memory usage when there are more
3660 back references than supplied space in the ovector. This could cause segfaults.
3661
3662
3663 Version 0.97 21-Oct-97
3664 ----------------------
3665
3666 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3667
3668 2. Optimized negated single characters not to use a bit map.
3669
3670 3. Brought error texts together as macro definitions; clarified some of them;
3671 fixed one that was wrong - it said "range out of order" when it meant "invalid
3672 escape sequence".
3673
3674 4. Changed some char * arguments to const char *.
3675
3676 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3677
3678 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3679 pcretest.
3680
3681
3682 Version 0.96 16-Oct-97
3683 ----------------------
3684
3685 1. Added a simple "pgrep" utility to the distribution.
3686
3687 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3688 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3689 where "ddd" means "one or more decimal digits".
3690
3691 3. Fixed serious bug. If a pattern had a back reference, but the call to
3692 pcre_exec() didn't supply a large enough ovector to record the related
3693 identifying subpattern, the match always failed. PCRE now remembers the number
3694 of the largest back reference, and gets some temporary memory in which to save
3695 the offsets during matching if necessary, in order to ensure that
3696 backreferences always work.
3697
3698 4. Increased the compatibility with Perl in a number of ways:
3699
3700 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3701 to request this handling. The option can be set at compile or exec time.
3702
3703 (b) $ matches before a terminating newline by default; an option
3704 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3705 mode). The option can be set at compile or exec time.
3706
3707 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3708 the same as Perl's. If the decimal number it represents is less than 10
3709 or there aren't that many previous left capturing parentheses, an octal
3710 escape is read. Inside a character class, it's always an octal escape,
3711 even if it is a single digit.
3712
3713 (d) An escaped but undefined alphabetic character is taken as a literal,
3714 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3715 escapes.
3716
3717 (e) {0} is now permitted. (The previous item is removed from the compiled
3718 pattern).
3719
3720 5. Changed all the names of code files so that the basic parts are no longer
3721 than 10 characters, and abolished the teeny "globals.c" file.
3722
3723 6. Changed the handling of character classes; they are now done with a 32-byte
3724 bit map always.
3725
3726 7. Added the -d and /D options to pcretest to make it possible to look at the
3727 internals of compilation without having to recompile pcre.
3728
3729
3730 Version 0.95 23-Sep-97
3731 ----------------------
3732
3733 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3734 \x20 at the start of a run of normal characters. These were being treated as
3735 real characters, instead of the source characters being re-checked.
3736
3737
3738 Version 0.94 18-Sep-97
3739 ----------------------
3740
3741 1. The functions are now thread-safe, with the caveat that the global variables
3742 containing pointers to malloc() and free() or alternative functions are the
3743 same for all threads.
3744
3745 2. Get pcre_study() to generate a bitmap of initial characters for non-
3746 anchored patterns when this is possible, and use it if passed to pcre_exec().
3747
3748
3749 Version 0.93 15-Sep-97
3750 ----------------------
3751
3752 1. /(b)|(:+)/ was computing an incorrect first character.
3753
3754 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3755 but not actually doing anything yet.
3756
3757 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3758 as Perl does (e.g. [-az] or [az-]).
3759
3760 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3761 all possible positions.
3762
3763 5. Split up into different modules to avoid including unneeded functions in a
3764 compiled binary. However, compile and exec are still in one module. The "study"
3765 function is split off.
3766
3767 6. The character tables are now in a separate module whose source is generated
3768 by an auxiliary program - but can then be edited by hand if required. There are
3769 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3770 toupper() in the code.
3771
3772 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3773 make them global. Abolish the function for setting them, as the caller can now
3774 set them directly.
3775
3776
3777 Version 0.92 11-Sep-97
3778 ----------------------
3779
3780 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3781 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3782
3783 2. Caseless matching was not working in character classes if the characters in
3784 the pattern were in upper case.
3785
3786 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3787
3788 4. Make PCRE_ANCHORED public and accept as a compile option.
3789
3790 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3791 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3792 pass them.
3793
3794 6. Give an error if bad option bits passed at compile or run time.
3795
3796 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3797 pcretest to cause it to pass that flag.
3798
3799 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3800 options, and the first character, if set.
3801
3802 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3803
3804
3805 Version 0.91 10-Sep-97
3806 ----------------------
3807
3808 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3809 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3810
3811 2. PCRE was looping on encountering an indefinitely repeated back reference to
3812 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3813 Perl does - treats the match as successful.
3814
3815 ****

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