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Revision 497 - (show annotations)
Wed Mar 3 12:01:00 2010 UTC (5 years, 3 months ago) by ph10
File size: 182594 byte(s)
Error occurred while calculating annotation data.
Use local function indirection for pcre_malloc etc. for Visual Studio and 
Symbian.
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 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
19 quantifier applied to a forward-referencing subroutine call, could compile
20 incorrect code or give the error "internal error: previously-checked
21 referenced subpattern not found".
22
23 6. Both MS Visual Studio and Symbian OS have problems with initializing
24 variables to point to external functions. For these systems, therefore,
25 pcre_malloc etc. are now initialized to local functions that call the
26 relevant global functions.
27
28
29 Version 8.01 19-Jan-2010
30 ------------------------
31
32 1. If a pattern contained a conditional subpattern with only one branch (in
33 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
34 computed the wrong minimum data length (which is of course zero for such
35 subpatterns). This could cause incorrect "no match" results.
36
37 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
38 the pattern is reset in the first branch, pcre_compile() failed with
39 "internal error: code overflow at offset...". This happened only when
40 the reset was to the original external option setting. (An optimization
41 abstracts leading options settings into an external setting, which was the
42 cause of this.)
43
44 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
45 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
46 assertion pattern did not match (meaning that the assertion was true), it
47 was incorrectly treated as false if the SKIP had been reached during the
48 matching. This also applied to assertions used as conditions.
49
50 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
51 assertion subpattern, including such a pattern used as a condition,
52 unpredictable results occurred, instead of the error return
53 PCRE_ERROR_DFA_UITEM.
54
55 5. The C++ GlobalReplace function was not working like Perl for the special
56 situation when an empty string is matched. It now does the fancy magic
57 stuff that is necessary.
58
59 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
60 removed. (These were left over from very, very early versions of PCRE.)
61
62 7. Some cosmetic changes to the code to make life easier when compiling it
63 as part of something else:
64
65 (a) Change DEBUG to PCRE_DEBUG.
66
67 (b) In pcre_compile(), rename the member of the "branch_chain" structure
68 called "current" as "current_branch", to prevent a collision with the
69 Linux macro when compiled as a kernel module.
70
71 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
72 prevent a collision with the Linux macro when compiled as a kernel
73 module.
74
75 8. In pcre_compile() there are some checks for integer overflows that used to
76 cast potentially large values to (double). This has been changed to that
77 when building, a check for int64_t is made, and if it is found, it is used
78 instead, thus avoiding the use of floating point arithmetic. (There is no
79 other use of FP in PCRE.) If int64_t is not found, the fallback is to
80 double.
81
82 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
83 2005 (difference between two addresses compared to an unsigned value).
84
85 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
86 custom one, because of the following reported problem in Windows:
87
88 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
89 under Win32.
90 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
91 therefore missing the function definition.
92 - The compiler thus generates a "C" signature for the test function.
93 - The linker fails to find the "C" function.
94 - PCRE fails to configure if asked to do so against libbz2.
95
96 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
97 messages were output:
98
99 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
100 rerunning libtoolize, to keep the correct libtool macros in-tree.
101 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
102
103 I have done both of these things.
104
105 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
106 most of the time, it *can* run out if it is given a pattern that contains a
107 runaway infinite recursion. I updated the discussion in the pcrestack man
108 page.
109
110 13. Now that we have gone to the x.xx style of version numbers, the minor
111 version may start with zero. Using 08 or 09 is a bad idea because users
112 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
113 interpreted as invalid octal numbers. I've updated the previous comment in
114 configure.ac, and also added a check that gives an error if 08 or 09 are
115 used.
116
117 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
118 causing partial matching to fail when the end of the subject matched \W
119 in a UTF-8 pattern where \W was quantified with a minimum of 3.
120
121 15. There were some discrepancies between the declarations in pcre_internal.h
122 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
123 their definitions. The declarations used "const uschar *" and the
124 definitions used USPTR. Even though USPTR is normally defined as "const
125 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
126 reported that: "This difference in casting confuses some C++ compilers, for
127 example, SunCC recognizes above declarations as different functions and
128 generates broken code for hbpcre." I have changed the declarations to use
129 USPTR.
130
131 16. GNU libtool is named differently on some systems. The autogen.sh script now
132 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
133 (FreeBSD).
134
135 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
136 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
137 comment: "Figure out how to create a longlong from a string: strtoll and
138 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
139 instance, but it only takes 2 args instead of 3!"
140
141 18. A subtle bug concerned with back references has been fixed by a change of
142 specification, with a corresponding code fix. A pattern such as
143 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
144 refers, was giving matches when it shouldn't. For example, xa=xaaa would
145 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
146 same bug. Such groups have to be quantified to be useful, or contained
147 inside another quantified group. (If there's no repetition, the reference
148 can never match.) The problem arises because, having left the group and
149 moved on to the rest of the pattern, a later failure that backtracks into
150 the group uses the captured value from the final iteration of the group
151 rather than the correct earlier one. I have fixed this in PCRE by forcing
152 any group that contains a reference to itself to be an atomic group; that
153 is, there cannot be any backtracking into it once it has completed. This is
154 similar to recursive and subroutine calls.
155
156
157 Version 8.00 19-Oct-09
158 ----------------------
159
160 1. The table for translating pcre_compile() error codes into POSIX error codes
161 was out-of-date, and there was no check on the pcre_compile() error code
162 being within the table. This could lead to an OK return being given in
163 error.
164
165 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
166 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
167 in a Windows environment.
168
169 3. The pcregrep --count option prints the count for each file even when it is
170 zero, as does GNU grep. However, pcregrep was also printing all files when
171 --files-with-matches was added. Now, when both options are given, it prints
172 counts only for those files that have at least one match. (GNU grep just
173 prints the file name in this circumstance, but including the count seems
174 more useful - otherwise, why use --count?) Also ensured that the
175 combination -clh just lists non-zero counts, with no names.
176
177 4. The long form of the pcregrep -F option was incorrectly implemented as
178 --fixed_strings instead of --fixed-strings. This is an incompatible change,
179 but it seems right to fix it, and I didn't think it was worth preserving
180 the old behaviour.
181
182 5. The command line items --regex=pattern and --regexp=pattern were not
183 recognized by pcregrep, which required --regex pattern or --regexp pattern
184 (with a space rather than an '='). The man page documented the '=' forms,
185 which are compatible with GNU grep; these now work.
186
187 6. No libpcreposix.pc file was created for pkg-config; there was just
188 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
189
190 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
191 when UCP support is not needed, by modifying the Python script that
192 generates it from Unicode data files. This should not matter if the module
193 is correctly used as a library, but I received one complaint about 50K of
194 unwanted data. My guess is that the person linked everything into his
195 program rather than using a library. Anyway, it does no harm.
196
197 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
198 was a minimum greater than 1 for a wide character in a possessive
199 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
200 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
201 character. Chaos in the form of incorrect output or a compiling loop could
202 result.
203
204 9. The restrictions on what a pattern can contain when partial matching is
205 requested for pcre_exec() have been removed. All patterns can now be
206 partially matched by this function. In addition, if there are at least two
207 slots in the offset vector, the offset of the earliest inspected character
208 for the match and the offset of the end of the subject are set in them when
209 PCRE_ERROR_PARTIAL is returned.
210
211 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
212 synonymous with PCRE_PARTIAL, for backwards compatibility, and
213 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
214 and may be more useful for multi-segment matching.
215
216 11. Partial matching with pcre_exec() is now more intuitive. A partial match
217 used to be given if ever the end of the subject was reached; now it is
218 given only if matching could not proceed because another character was
219 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
220 string "Z", which now yields "no match" instead of "partial match". In the
221 case of pcre_dfa_exec(), "no match" is given if every matching path for the
222 final character ended with (*FAIL).
223
224 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
225 if the pattern had a "must contain" character that was already found in the
226 earlier partial match, unless partial matching was again requested. For
227 example, with the pattern /dog.(body)?/, the "must contain" character is
228 "g". If the first part-match was for the string "dog", restarting with
229 "sbody" failed. This bug has been fixed.
230
231 13. The string returned by pcre_dfa_exec() after a partial match has been
232 changed so that it starts at the first inspected character rather than the
233 first character of the match. This makes a difference only if the pattern
234 starts with a lookbehind assertion or \b or \B (\K is not supported by
235 pcre_dfa_exec()). It's an incompatible change, but it makes the two
236 matching functions compatible, and I think it's the right thing to do.
237
238 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
239 so that the demonstration program is easily available in environments where
240 PCRE has not been installed from source.
241
242 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
243 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
244 library.
245
246 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
247 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
248 is not the first non-POSIX option to be added. Clearly some people find
249 these options useful.
250
251 17. If a caller to the POSIX matching function regexec() passes a non-zero
252 value for nmatch with a NULL value for pmatch, the value of
253 nmatch is forced to zero.
254
255 18. RunGrepTest did not have a test for the availability of the -u option of
256 the diff command, as RunTest does. It now checks in the same way as
257 RunTest, and also checks for the -b option.
258
259 19. If an odd number of negated classes containing just a single character
260 interposed, within parentheses, between a forward reference to a named
261 subpattern and the definition of the subpattern, compilation crashed with
262 an internal error, complaining that it could not find the referenced
263 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
264 [The bug was that it was starting one character too far in when skipping
265 over the character class, thus treating the ] as data rather than
266 terminating the class. This meant it could skip too much.]
267
268 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
269 /g option in pcretest when the pattern contains \K, which makes it possible
270 to have an empty string match not at the start, even when the pattern is
271 anchored. Updated pcretest and pcredemo to use this option.
272
273 21. If the maximum number of capturing subpatterns in a recursion was greater
274 than the maximum at the outer level, the higher number was returned, but
275 with unset values at the outer level. The correct (outer level) value is
276 now given.
277
278 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
279 PCRE did not set those parentheses (unlike Perl). I have now found a way to
280 make it do so. The string so far is captured, making this feature
281 compatible with Perl.
282
283 23. The tests have been re-organized, adding tests 11 and 12, to make it
284 possible to check the Perl 5.10 features against Perl 5.10.
285
286 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
287 pattern matches a fixed length string. PCRE did not allow this; now it
288 does. Neither allows recursion.
289
290 25. I finally figured out how to implement a request to provide the minimum
291 length of subject string that was needed in order to match a given pattern.
292 (It was back references and recursion that I had previously got hung up
293 on.) This code has now been added to pcre_study(); it finds a lower bound
294 to the length of subject needed. It is not necessarily the greatest lower
295 bound, but using it to avoid searching strings that are too short does give
296 some useful speed-ups. The value is available to calling programs via
297 pcre_fullinfo().
298
299 26. While implementing 25, I discovered to my embarrassment that pcretest had
300 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
301 study optimizations had never been tested with that matching function.
302 Oops. What is worse, even when it was passed study data, there was a bug in
303 pcre_dfa_exec() that meant it never actually used it. Double oops. There
304 were also very few tests of studied patterns with pcre_dfa_exec().
305
306 27. If (?| is used to create subpatterns with duplicate numbers, they are now
307 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
308 on the other side of the coin, they are no longer allowed to have different
309 names, because these cannot be distinguished in PCRE, and this has caused
310 confusion. (This is a difference from Perl.)
311
312 28. When duplicate subpattern names are present (necessarily with different
313 numbers, as required by 27 above), and a test is made by name in a
314 conditional pattern, either for a subpattern having been matched, or for
315 recursion in such a pattern, all the associated numbered subpatterns are
316 tested, and the overall condition is true if the condition is true for any
317 one of them. This is the way Perl works, and is also more like the way
318 testing by number works.
319
320
321 Version 7.9 11-Apr-09
322 ---------------------
323
324 1. When building with support for bzlib/zlib (pcregrep) and/or readline
325 (pcretest), all targets were linked against these libraries. This included
326 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
327 libraries. This caused unwanted dependencies to be created. This problem
328 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
329 pcretest is linked with readline.
330
331 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
332 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
333 moved outside it again, because FALSE and TRUE are already defined in AIX,
334 but BOOL is not.
335
336 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
337 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
338
339 4. The pcregrep documentation said spaces were inserted as well as colons (or
340 hyphens) following file names and line numbers when outputting matching
341 lines. This is not true; no spaces are inserted. I have also clarified the
342 wording for the --colour (or --color) option.
343
344 5. In pcregrep, when --colour was used with -o, the list of matching strings
345 was not coloured; this is different to GNU grep, so I have changed it to be
346 the same.
347
348 6. When --colo(u)r was used in pcregrep, only the first matching substring in
349 each matching line was coloured. Now it goes on to look for further matches
350 of any of the test patterns, which is the same behaviour as GNU grep.
351
352 7. A pattern that could match an empty string could cause pcregrep to loop; it
353 doesn't make sense to accept an empty string match in pcregrep, so I have
354 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
355 seems to be how GNU grep behaves.
356
357 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
358 start or after a newline", because the conditional assertion was not being
359 correctly handled. The rule now is that both the assertion and what follows
360 in the first alternative must satisfy the test.
361
362 9. If auto-callout was enabled in a pattern with a conditional group whose
363 condition was an assertion, PCRE could crash during matching, both with
364 pcre_exec() and pcre_dfa_exec().
365
366 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
367 used for matching.
368
369 11. Unicode property support in character classes was not working for
370 characters (bytes) greater than 127 when not in UTF-8 mode.
371
372 12. Added the -M command line option to pcretest.
373
374 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
375
376 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
377
378 16. Added comments and documentation about mis-use of no_arg in the C++
379 wrapper.
380
381 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
382 from Martin Jerabek that uses macro names for all relevant character and
383 string constants.
384
385 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
386 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
387 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
388 these, but not everybody uses configure.
389
390 19. A conditional group that had only one branch was not being correctly
391 recognized as an item that could match an empty string. This meant that an
392 enclosing group might also not be so recognized, causing infinite looping
393 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
394 with the subject "ab", where knowledge that the repeated group can match
395 nothing is needed in order to break the loop.
396
397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
398 exec(), but without supplying a callout function, matching went wrong.
399
400 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
401 leak if the size of the offset vector was greater than 30. When the vector
402 is smaller, the saved offsets during recursion go onto a local stack
403 vector, but for larger vectors malloc() is used. It was failing to free
404 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
405 error, in fact).
406
407 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
408 heapframe that is used only when UTF-8 support is enabled. This caused no
409 problem, but was untidy.
410
411 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
412 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
413 included within another project.
414
415 24. Steven Van Ingelgem's patches to add more options to the CMake support,
416 slightly modified by me:
417
418 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
419 not building pcregrep.
420
421 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
422 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
423
424 25. Forward references, both numeric and by name, in patterns that made use of
425 duplicate group numbers, could behave incorrectly or give incorrect errors,
426 because when scanning forward to find the reference group, PCRE was not
427 taking into account the duplicate group numbers. A pattern such as
428 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
429
430 26. Changed a few more instances of "const unsigned char *" to USPTR, making
431 the feature of a custom pointer more persuasive (as requested by a user).
432
433 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
434 pcretest.c, inside #ifndefs, because it seems they are sometimes already
435 pre-defined.
436
437 28. Added support for (*UTF8) at the start of a pattern.
438
439 29. Arrange for flags added by the "release type" setting in CMake to be shown
440 in the configuration summary.
441
442
443 Version 7.8 05-Sep-08
444 ---------------------
445
446 1. Replaced UCP searching code with optimized version as implemented for Ad
447 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
448 stage table and inline lookup instead of a function, giving speed ups of 2
449 to 5 times on some simple patterns that I tested. Permission was given to
450 distribute the MultiStage2.py script that generates the tables (it's not in
451 the tarball, but is in the Subversion repository).
452
453 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
454 scripts.
455
456 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
457 a group with a zero qualifier. The result of the study could be incorrect,
458 or the function might crash, depending on the pattern.
459
460 4. Caseless matching was not working for non-ASCII characters in back
461 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
462 It now works when Unicode Property Support is available.
463
464 5. In pcretest, an escape such as \x{de} in the data was always generating
465 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
466 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
467 truncation.
468
469 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
470
471 7. Added two (int) casts to pcregrep when printing the difference of two
472 pointers, in case they are 64-bit values.
473
474 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
475 test 2 if it fails.
476
477 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
478 and a #define of that name to empty if it is not externally set. This is to
479 allow users of MSVC to set it if necessary.
480
481 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
482 the convenience functions in the pcre_get.c source file.
483
484 11. An option change at the start of a pattern that had top-level alternatives
485 could cause overwriting and/or a crash. This command provoked a crash in
486 some environments:
487
488 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
489
490 This potential security problem was recorded as CVE-2008-2371.
491
492 12. For a pattern where the match had to start at the beginning or immediately
493 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
494 pcre_dfa_exec() could read past the end of the passed subject if there was
495 no match. To help with detecting such bugs (e.g. with valgrind), I modified
496 pcretest so that it places the subject at the end of its malloc-ed buffer.
497
498 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
499 exec() might read past the end of the data buffer in UTF-8 mode.
500
501 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
502 the data contained the byte 0x85 as part of a UTF-8 character within its
503 first line. This applied both to normal and DFA matching.
504
505 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
506 /^[^d]*?$/8 failed to match "abc".
507
508 16. Added a missing copyright notice to pcrecpp_internal.h.
509
510 17. Make it more clear in the documentation that values returned from
511 pcre_exec() in ovector are byte offsets, not character counts.
512
513 18. Tidied a few places to stop certain compilers from issuing warnings.
514
515 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
516 supplied by Stefan Weber. I made a further small update for 7.8 because
517 there is a change of source arrangements: the pcre_searchfuncs.c module is
518 replaced by pcre_ucd.c.
519
520
521 Version 7.7 07-May-08
522 ---------------------
523
524 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
525 a string to a long long, pretend we don't even have a long long." This is
526 done by checking for the strtoq, strtoll, and _strtoi64 functions.
527
528 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
529 pre-7.6 versions, which defined a global no_arg variable instead of putting
530 it in the RE class. (See also #8 below.)
531
532 3. Remove a line of dead code, identified by coverity and reported by Nuno
533 Lopes.
534
535 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
536
537 (1) The include/exclude patterns were being applied to the whole pathnames
538 of files, instead of just to the final components.
539
540 (2) If there was more than one level of directory, the subdirectories were
541 skipped unless they satisfied the include/exclude conditions. This is
542 inconsistent with GNU grep (and could even be seen as contrary to the
543 pcregrep specification - which I improved to make it absolutely clear).
544 The action now is always to scan all levels of directory, and just
545 apply the include/exclude patterns to regular files.
546
547 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
548 --exclude_dir in the tests to avoid scanning .svn directories.
549
550 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
551 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
552 doesn't support NULs in patterns.
553
554 7. Added some missing "const"s to declarations of static tables in
555 pcre_compile.c and pcre_dfa_exec.c.
556
557 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
558 caused by fix #2 above. (Subsequently also a second patch to fix the
559 first patch. And a third patch - this was a messy problem.)
560
561 9. Applied Craig's patch to remove the use of push_back().
562
563 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
564 matching function regexec().
565
566 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
567 which, however, unlike Perl's \g{...}, are subroutine calls, not back
568 references. PCRE supports relative numbers with this syntax (I don't think
569 Oniguruma does).
570
571 12. Previously, a group with a zero repeat such as (...){0} was completely
572 omitted from the compiled regex. However, this means that if the group
573 was called as a subroutine from elsewhere in the pattern, things went wrong
574 (an internal error was given). Such groups are now left in the compiled
575 pattern, with a new opcode that causes them to be skipped at execution
576 time.
577
578 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
579 to the way PCRE behaves:
580
581 (a) A lone ] character is dis-allowed (Perl treats it as data).
582
583 (b) A back reference to an unmatched subpattern matches an empty string
584 (Perl fails the current match path).
585
586 (c) A data ] in a character class must be notated as \] because if the
587 first data character in a class is ], it defines an empty class. (In
588 Perl it is not possible to have an empty class.) The empty class []
589 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
590 The negative empty class [^] matches any one character, independently
591 of the DOTALL setting.
592
593 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
594 non-existent subpattern following a character class starting with ']' and
595 containing () gave an internal compiling error instead of "reference to
596 non-existent subpattern". Fortunately, when the pattern did exist, the
597 compiled code was correct. (When scanning forwards to check for the
598 existencd of the subpattern, it was treating the data ']' as terminating
599 the class, so got the count wrong. When actually compiling, the reference
600 was subsequently set up correctly.)
601
602 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
603 it was being rejected as not supported by pcre_dfa_exec(), even though
604 other assertions are supported. I have made pcre_dfa_exec() support
605 (*FAIL).
606
607 16. The implementation of 13c above involved the invention of a new opcode,
608 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
609 cannot be changed at match time, I realized I could make a small
610 improvement to matching performance by compiling OP_ALLANY instead of
611 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
612 on the OP_ANY path.
613
614 17. Compiling pcretest on Windows with readline support failed without the
615 following two fixes: (1) Make the unistd.h include conditional on
616 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
617
618 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
619 ncurses library to be included for pcretest when ReadLine support is
620 requested, but also to allow for it to be overridden. This patch came from
621 Daniel Bergström.
622
623 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
624 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
625 any errors with the current Unicode tables. Thanks to Peter Kankowski for
626 spotting this.
627
628
629 Version 7.6 28-Jan-08
630 ---------------------
631
632 1. A character class containing a very large number of characters with
633 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
634 overflow.
635
636 2. Patch to cut out the "long long" test in pcrecpp_unittest when
637 HAVE_LONG_LONG is not defined.
638
639 3. Applied Christian Ehrlicher's patch to update the CMake build files to
640 bring them up to date and include new features. This patch includes:
641
642 - Fixed PH's badly added libz and libbz2 support.
643 - Fixed a problem with static linking.
644 - Added pcredemo. [But later removed - see 7 below.]
645 - Fixed dftables problem and added an option.
646 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
647 HAVE_LONG_LONG.
648 - Added readline support for pcretest.
649 - Added an listing of the option settings after cmake has run.
650
651 4. A user submitted a patch to Makefile that makes it easy to create
652 "pcre.dll" under mingw when using Configure/Make. I added stuff to
653 Makefile.am that cause it to include this special target, without
654 affecting anything else. Note that the same mingw target plus all
655 the other distribution libraries and programs are now supported
656 when configuring with CMake (see 6 below) instead of with
657 Configure/Make.
658
659 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
660 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
661 exported in the Windows port". It has not yet been confirmed that the patch
662 solves the problem, but it does no harm.
663
664 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
665 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
666 with CMake, and also correct the comment about stack recursion.
667
668 7. Remove the automatic building of pcredemo from the ./configure system and
669 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
670 of a program that users should build themselves after PCRE is installed, so
671 building it automatically is not really right. What is more, it gave
672 trouble in some build environments.
673
674 8. Further tidies to CMakeLists.txt from Sheri and Christian.
675
676
677 Version 7.5 10-Jan-08
678 ---------------------
679
680 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
681 values in parens when parsing an RE using the C++ wrapper."
682
683 2. Negative specials like \S did not work in character classes in UTF-8 mode.
684 Characters greater than 255 were excluded from the class instead of being
685 included.
686
687 3. The same bug as (2) above applied to negated POSIX classes such as
688 [:^space:].
689
690 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
691 defined or documented. It seems to have been a typo for PCRE_STATIC, so
692 I have changed it.
693
694 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
695 first named subpattern) and a construct such as (?&a) would reference the
696 first named subpattern whose name started with "a" (in other words, the
697 length check was missing). Both these problems are fixed. "Subpattern name
698 expected" is now given for (?&) (a zero-length name), and this patch also
699 makes it give the same error for \k'' (previously it complained that that
700 was a reference to a non-existent subpattern).
701
702 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
703 this is right because (?- can be followed by option settings as well as by
704 digits. I have, however, made the messages clearer.
705
706 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
707 than the number used in the conditional) now cause a compile-time error.
708 This is actually not compatible with Perl, which accepts such patterns, but
709 treats the conditional as always being FALSE (as PCRE used to), but it
710 seems to me that giving a diagnostic is better.
711
712 8. Change "alphameric" to the more common word "alphanumeric" in comments
713 and messages.
714
715 9. Fix two occurrences of "backslash" in comments that should have been
716 "backspace".
717
718 10. Remove two redundant lines of code that can never be obeyed (their function
719 was moved elsewhere).
720
721 11. The program that makes PCRE's Unicode character property table had a bug
722 which caused it to generate incorrect table entries for sequences of
723 characters that have the same character type, but are in different scripts.
724 It amalgamated them into a single range, with the script of the first of
725 them. In other words, some characters were in the wrong script. There were
726 thirteen such cases, affecting characters in the following ranges:
727
728 U+002b0 - U+002c1
729 U+0060c - U+0060d
730 U+0061e - U+00612
731 U+0064b - U+0065e
732 U+0074d - U+0076d
733 U+01800 - U+01805
734 U+01d00 - U+01d77
735 U+01d9b - U+01dbf
736 U+0200b - U+0200f
737 U+030fc - U+030fe
738 U+03260 - U+0327f
739 U+0fb46 - U+0fbb1
740 U+10450 - U+1049d
741
742 12. The -o option (show only the matching part of a line) for pcregrep was not
743 compatible with GNU grep in that, if there was more than one match in a
744 line, it showed only the first of them. It now behaves in the same way as
745 GNU grep.
746
747 13. If the -o and -v options were combined for pcregrep, it printed a blank
748 line for every non-matching line. GNU grep prints nothing, and pcregrep now
749 does the same. The return code can be used to tell if there were any
750 non-matching lines.
751
752 14. Added --file-offsets and --line-offsets to pcregrep.
753
754 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
755 infinitely looping recursion. The bug was that positive lookaheads were not
756 being skipped when checking for a possible empty match (negative lookaheads
757 and both kinds of lookbehind were skipped).
758
759 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
760 inclusion of <windows.h> to before rather than after the definition of
761 INVALID_FILE_ATTRIBUTES (patch from David Byron).
762
763 17. Specifying a possessive quantifier with a specific limit for a Unicode
764 character property caused pcre_compile() to compile bad code, which led at
765 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
766 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
767 caused the error; without that there was no problem.
768
769 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
770
771 19. Added --enable-pcretest-libreadline.
772
773 20. In pcrecpp.cc, the variable 'count' was incremented twice in
774 RE::GlobalReplace(). As a result, the number of replacements returned was
775 double what it should be. I removed one of the increments, but Craig sent a
776 later patch that removed the other one (the right fix) and added unit tests
777 that check the return values (which was not done before).
778
779 21. Several CMake things:
780
781 (1) Arranged that, when cmake is used on Unix, the libraries end up with
782 the names libpcre and libpcreposix, not just pcre and pcreposix.
783
784 (2) The above change means that pcretest and pcregrep are now correctly
785 linked with the newly-built libraries, not previously installed ones.
786
787 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
788
789 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
790 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
791 UTF-8 newline character). The key issue is that the pattern starts .*;
792 this means that the match must be either at the beginning, or after a
793 newline. The bug was in the code for advancing after a failed match and
794 checking that the new position followed a newline. It was not taking
795 account of UTF-8 characters correctly.
796
797 23. PCRE was behaving differently from Perl in the way it recognized POSIX
798 character classes. PCRE was not treating the sequence [:...:] as a
799 character class unless the ... were all letters. Perl, however, seems to
800 allow any characters between [: and :], though of course it rejects as
801 unknown any "names" that contain non-letters, because all the known class
802 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
803 for example, whereas PCRE did not - it did not recognize a POSIX character
804 class. This seemed a bit dangerous, so the code has been changed to be
805 closer to Perl. The behaviour is not identical to Perl, because PCRE will
806 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
807 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
808 Perl does, and where it didn't before.
809
810 24. Rewrite so as to remove the single use of %n from pcregrep because in some
811 Windows environments %n is disabled by default.
812
813
814 Version 7.4 21-Sep-07
815 ---------------------
816
817 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
818 means that a class such as [\s] counted as "explicit reference to CR or
819 LF". That isn't really right - the whole point of the change was to try to
820 help when there was an actual mention of one of the two characters. So now
821 the change happens only if \r or \n (or a literal CR or LF) character is
822 encountered.
823
824 2. The 32-bit options word was also used for 6 internal flags, but the numbers
825 of both had grown to the point where there were only 3 bits left.
826 Fortunately, there was spare space in the data structure, and so I have
827 moved the internal flags into a new 16-bit field to free up more option
828 bits.
829
830 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
831 but did not set the internal JCHANGED flag - either of these is enough to
832 control the way the "get" function works - but the PCRE_INFO_JCHANGED
833 facility is supposed to tell if (?J) was ever used, so now (?J) at the
834 start sets both bits.
835
836 4. Added options (at build time, compile time, exec time) to change \R from
837 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
838
839 5. doc/pcresyntax.html was missing from the distribution.
840
841 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
842 compatibility, even though it is no longer used.
843
844 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
845 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
846 windows.h file is present (where different names are used). [This was
847 reversed later after testing - see 16 below.]
848
849 8. Changed all #include <config.h> to #include "config.h". There were also
850 some further <pcre.h> cases that I changed to "pcre.h".
851
852 9. When pcregrep was used with the --colour option, it missed the line ending
853 sequence off the lines that it output.
854
855 10. It was pointed out to me that arrays of string pointers cause lots of
856 relocations when a shared library is dynamically loaded. A technique of
857 using a single long string with a table of offsets can drastically reduce
858 these. I have refactored PCRE in four places to do this. The result is
859 dramatic:
860
861 Originally: 290
862 After changing UCP table: 187
863 After changing error message table: 43
864 After changing table of "verbs" 36
865 After changing table of Posix names 22
866
867 Thanks to the folks working on Gregex for glib for this insight.
868
869 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
870 unicode-properties was also set.
871
872 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
873
874 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
875 checked only for CRLF.
876
877 14. Added casts to pcretest.c to avoid compiler warnings.
878
879 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
880
881 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
882 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
883 entirely. This removes changes made in 7 above.
884
885 17. The CMake files have been updated, and there is now more information about
886 building with CMake in the NON-UNIX-USE document.
887
888
889 Version 7.3 28-Aug-07
890 ---------------------
891
892 1. In the rejigging of the build system that eventually resulted in 7.1, the
893 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
894 brackets there is not right, since it causes compilers to look for an
895 installed pcre.h, not the version that is in the source that is being
896 compiled (which of course may be different). I have changed it back to:
897
898 #include "pcre.h"
899
900 I have a vague recollection that the change was concerned with compiling in
901 different directories, but in the new build system, that is taken care of
902 by the VPATH setting the Makefile.
903
904 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
905 when the subject happened to end in the byte 0x85 (e.g. if the last
906 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
907 characters but of course it shouldn't be taken as a newline when it is part
908 of another character. The bug was that, for an unlimited repeat of . in
909 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
910 characters when looking for a newline.
911
912 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
913
914 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
915 in debug output.
916
917 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
918 long printing in the pcrecpp unittest when running under MinGW.
919
920 6. ESC_K was left out of the EBCDIC table.
921
922 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
923 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
924 limit also applies to "virtual nesting" when a pattern is recursive, and in
925 this case 1000 isn't so big. I have been able to remove this limit at the
926 expense of backing off one optimization in certain circumstances. Normally,
927 when pcre_exec() would call its internal match() function recursively and
928 immediately return the result unconditionally, it uses a "tail recursion"
929 feature to save stack. However, when a subpattern that can match an empty
930 string has an unlimited repetition quantifier, it no longer makes this
931 optimization. That gives it a stack frame in which to save the data for
932 checking that an empty string has been matched. Previously this was taken
933 from the 1000-entry workspace that had been reserved. So now there is no
934 explicit limit, but more stack is used.
935
936 8. Applied Daniel's patches to solve problems with the import/export magic
937 syntax that is required for Windows, and which was going wrong for the
938 pcreposix and pcrecpp parts of the library. These were overlooked when this
939 problem was solved for the main library.
940
941 9. There were some crude static tests to avoid integer overflow when computing
942 the size of patterns that contain repeated groups with explicit upper
943 limits. As the maximum quantifier is 65535, the maximum group length was
944 set at 30,000 so that the product of these two numbers did not overflow a
945 32-bit integer. However, it turns out that people want to use groups that
946 are longer than 30,000 bytes (though not repeat them that many times).
947 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
948 made it possible to implement the integer overflow checks in a much more
949 dynamic way, which I have now done. The artificial limitation on group
950 length has been removed - we now have only the limit on the total length of
951 the compiled pattern, which depends on the LINK_SIZE setting.
952
953 10. Fixed a bug in the documentation for get/copy named substring when
954 duplicate names are permitted. If none of the named substrings are set, the
955 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
956 empty string.
957
958 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
959 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
960 because the ] is interpreted as the first data character and the
961 terminating ] is not found. PCRE has been made compatible with Perl in this
962 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
963 cause memory overwriting.
964
965 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
966 string has been matched (to stop an infinite loop). It was not recognizing
967 a conditional subpattern that could match an empty string if that
968 subpattern was within another subpattern. For example, it looped when
969 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
970 condition was not nested. This bug has been fixed.
971
972 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
973 past the start of the subject in the presence of bytes with the top bit
974 set, for example "\x8aBCD".
975
976 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
977 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
978
979 14. Optimized (?!) to (*FAIL).
980
981 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
982 This restricts code points to be within the range 0 to 0x10FFFF, excluding
983 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
984 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
985 does: it's just the validity check that is more restrictive.
986
987 16. Inserted checks for integer overflows during escape sequence (backslash)
988 processing, and also fixed erroneous offset values for syntax errors during
989 backslash processing.
990
991 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
992 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
993
994 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
995 caused an overrun.
996
997 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
998 something other than just ASCII characters) inside a group that had an
999 unlimited repeat caused a loop at compile time (while checking to see
1000 whether the group could match an empty string).
1001
1002 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1003 [\P{Any}] did so. (Error in the code for printing property names.)
1004
1005 21. An orphan \E inside a character class could cause a crash.
1006
1007 22. A repeated capturing bracket such as (A)? could cause a wild memory
1008 reference during compilation.
1009
1010 23. There are several functions in pcre_compile() that scan along a compiled
1011 expression for various reasons (e.g. to see if it's fixed length for look
1012 behind). There were bugs in these functions when a repeated \p or \P was
1013 present in the pattern. These operators have additional parameters compared
1014 with \d, etc, and these were not being taken into account when moving along
1015 the compiled data. Specifically:
1016
1017 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1018 length.
1019
1020 (b) An item such as \pL+ within a repeated group could cause crashes or
1021 loops.
1022
1023 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1024 "reference to non-existent subpattern" error.
1025
1026 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1027
1028 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1029 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1030
1031 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1032
1033 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1034 character were causing crashes (broken optimization).
1035
1036 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1037 \p or \P) caused a compile-time loop.
1038
1039 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1040 break. For example, the unstudied pattern [\r\n]A does not match the string
1041 "\r\nA" because change 7.0/46 below moves the current point on by two
1042 characters after failing to match at the start. However, the pattern \nA
1043 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1044 the same is true. There doesn't seem any very clean way out of this, but
1045 what I have chosen to do makes the common cases work: PCRE now takes note
1046 of whether there can be an explicit match for \r or \n anywhere in the
1047 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1048 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1049 pattern has explicit CR or LF references.
1050
1051 29. Added (*CR) etc for changing newline setting at start of pattern.
1052
1053
1054 Version 7.2 19-Jun-07
1055 ---------------------
1056
1057 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1058 which is apparently normally available under Windows.
1059
1060 2. Re-jig the pcregrep tests with different newline settings in an attempt
1061 to make them independent of the local environment's newline setting.
1062
1063 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1064
1065 4. Some of the "internals" tests were previously cut out when the link size
1066 was not 2, because the output contained actual offsets. The recent new
1067 "Z" feature of pcretest means that these can be cut out, making the tests
1068 usable with all link sizes.
1069
1070 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1071 stack recursion. This gives a massive performance boost under BSD, but just
1072 a small improvement under Linux. However, it saves one field in the frame
1073 in all cases.
1074
1075 6. Added more features from the forthcoming Perl 5.10:
1076
1077 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1078 recursion call. It refers to the nth most recently opened parentheses.
1079
1080 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1081 to be opened parentheses.
1082
1083 (c) Conditions that refer to capturing parentheses can be specified
1084 relatively, for example, (?(-2)... or (?(+3)...
1085
1086 (d) \K resets the start of the current match so that everything before
1087 is not part of it.
1088
1089 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1090
1091 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1092 reference syntax.
1093
1094 (g) (?| introduces a group in which the numbering of parentheses in each
1095 alternative starts with the same number.
1096
1097 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1098
1099 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1100 PCRE_INFO_JCHANGED.
1101
1102 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1103 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1104 for detecting groups that can match an empty string.
1105
1106 9. A pattern with a very large number of alternatives (more than several
1107 hundred) was running out of internal workspace during the pre-compile
1108 phase, where pcre_compile() figures out how much memory will be needed. A
1109 bit of new cunning has reduced the workspace needed for groups with
1110 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1111 workspace instead of running out of the 4096 that are available.
1112
1113 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1114
1115 11. Applied patch from Google to remove an optimization that didn't quite work.
1116 The report of the bug said:
1117
1118 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1119 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1120 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1121
1122 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1123 it matched the wrong number of bytes.
1124
1125
1126 Version 7.1 24-Apr-07
1127 ---------------------
1128
1129 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1130 that is more "standard", making use of automake and other Autotools. There
1131 is some re-arrangement of the files and adjustment of comments consequent
1132 on this.
1133
1134 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1135 for recursive directory scanning broke on some systems because the files
1136 are not scanned in any specific order and on different systems the order
1137 was different. A call to "sort" has been inserted into RunGrepTest for the
1138 approprate test as a short-term fix. In the longer term there may be an
1139 alternative.
1140
1141 3. I had an email from Eric Raymond about problems translating some of PCRE's
1142 man pages to HTML (despite the fact that I distribute HTML pages, some
1143 people do their own conversions for various reasons). The problems
1144 concerned the use of low-level troff macros .br and .in. I have therefore
1145 removed all such uses from the man pages (some were redundant, some could
1146 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1147 HTML has been updated to handle .nf/.fi and to complain if it encounters
1148 .br or .in.
1149
1150 4. Updated comments in configure.ac that get placed in config.h.in and also
1151 arranged for config.h to be included in the distribution, with the name
1152 config.h.generic, for the benefit of those who have to compile without
1153 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1154
1155 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1156 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1157 makevp.bat for the current PCRE, using the additional files
1158 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1159
1160 6. A Windows user reported a minor discrepancy with test 2, which turned out
1161 to be caused by a trailing space on an input line that had got lost in his
1162 copy. The trailing space was an accident, so I've just removed it.
1163
1164 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1165 that is needed.
1166
1167 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1168 as "const" (a) because they are and (b) because it helps the PHP
1169 maintainers who have recently made a script to detect big data structures
1170 in the php code that should be moved to the .rodata section. I remembered
1171 to update Builducptable as well, so it won't revert if ucptable.h is ever
1172 re-created.
1173
1174 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1175 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1176 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1177 support is not required. This saves 1.5-2K of code, which is important in
1178 some applications.
1179
1180 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1181 so as not to refer to the tables, even though these functions will never be
1182 called when UTF-8 support is disabled. Otherwise there are problems with a
1183 shared library.
1184
1185 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1186
1187 (a) It was defining its arguments as char * instead of void *.
1188
1189 (b) It was assuming that all moves were upwards in memory; this was true
1190 a long time ago when I wrote it, but is no longer the case.
1191
1192 The emulated memove() is provided for those environments that have neither
1193 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1194 is clearly not the case, as these two bugs were recently reported.
1195
1196 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1197 and Detrail to create the HTML documentation, the .txt form of the man
1198 pages, and it removes trailing spaces from listed files. It also creates
1199 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1200 case, it wraps all the #defines with #ifndefs. This script should be run
1201 before "make dist".
1202
1203 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1204 with Unicode property support.
1205
1206 (a) For a maximizing quantifier, if the two different cases of the
1207 character were of different lengths in their UTF-8 codings (there are
1208 some cases like this - I found 11), and the matching function had to
1209 back up over a mixture of the two cases, it incorrectly assumed they
1210 were both the same length.
1211
1212 (b) When PCRE was configured to use the heap rather than the stack for
1213 recursion during matching, it was not correctly preserving the data for
1214 the other case of a UTF-8 character when checking ahead for a match
1215 while processing a minimizing repeat. If the check also involved
1216 matching a wide character, but failed, corruption could cause an
1217 erroneous result when trying to check for a repeat of the original
1218 character.
1219
1220 13. Some tidying changes to the testing mechanism:
1221
1222 (a) The RunTest script now detects the internal link size and whether there
1223 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1224 values substituted by "configure". (The RunGrepTest script already did
1225 this for UTF-8.) The configure.ac script no longer substitutes the
1226 relevant variables.
1227
1228 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1229 with length and offset values. This means that the output is different
1230 for different internal link sizes. Test 2 is skipped for link sizes
1231 other than 2 because of this, bypassing the problem. Unfortunately,
1232 there was also a test in test 3 (the locale tests) that used /B and
1233 failed for link sizes other than 2. Rather than cut the whole test out,
1234 I have added a new /Z option to pcretest that replaces the length and
1235 offset values with spaces. This is now used to make test 3 independent
1236 of link size. (Test 2 will be tidied up later.)
1237
1238 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1239 segmentation fault instead of returning the appropriate error message.
1240
1241 15. In multiline mode when the newline sequence was set to "any", the pattern
1242 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1243 This doesn't seem right; it now treats the CRLF combination as the line
1244 ending, and so does not match in that case. It's only a pattern such as ^$
1245 that would hit this one: something like ^ABC$ would have failed after \r
1246 and then tried again after \r\n.
1247
1248 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1249 in an attempt to make files that differ only in their line terminators
1250 compare equal. This works on Linux.
1251
1252 17. Under certain error circumstances pcregrep might try to free random memory
1253 as it exited. This is now fixed, thanks to valgrind.
1254
1255 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1256 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1257 was because its rules for how to advance for /g after matching an empty
1258 string at the end of a line did not allow for this case. They now check for
1259 it specially.
1260
1261 20. pcretest is supposed to handle patterns and data of any length, by
1262 extending its buffers when necessary. It was getting this wrong when the
1263 buffer for a data line had to be extended.
1264
1265 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1266 CRLF as a newline sequence.
1267
1268 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1269 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1270 I have nevertheless tidied it up.
1271
1272 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1273
1274 24. Added a man page for pcre-config.
1275
1276
1277 Version 7.0 19-Dec-06
1278 ---------------------
1279
1280 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1281 moving to gcc 4.1.1.
1282
1283 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1284 sys/time.h, which is documented as needed for this function. It doesn't
1285 seem to matter on Linux, but it showed up on some releases of OS X.
1286
1287 3. It seems that there are systems where bytes whose values are greater than
1288 127 match isprint() in the "C" locale. The "C" locale should be the
1289 default when a C program starts up. In most systems, only ASCII printing
1290 characters match isprint(). This difference caused the output from pcretest
1291 to vary, making some of the tests fail. I have changed pcretest so that:
1292
1293 (a) When it is outputting text in the compiled version of a pattern, bytes
1294 other than 32-126 are always shown as hex escapes.
1295
1296 (b) When it is outputting text that is a matched part of a subject string,
1297 it does the same, unless a different locale has been set for the match
1298 (using the /L modifier). In this case, it uses isprint() to decide.
1299
1300 4. Fixed a major bug that caused incorrect computation of the amount of memory
1301 required for a compiled pattern when options that changed within the
1302 pattern affected the logic of the preliminary scan that determines the
1303 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1304 that the computed length was too small. The symptoms of this bug were
1305 either the PCRE error "internal error: code overflow" from pcre_compile(),
1306 or a glibc crash with a message such as "pcretest: free(): invalid next
1307 size (fast)". Examples of patterns that provoked this bug (shown in
1308 pcretest format) are:
1309
1310 /(?-x: )/x
1311 /(?x)(?-x: \s*#\s*)/
1312 /((?i)[\x{c0}])/8
1313 /(?i:[\x{c0}])/8
1314
1315 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1316 is now done differently.
1317
1318 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1319 wrapper classes; (b) implement a new function in the C++ scanner that is
1320 more efficient than the old way of doing things because it avoids levels of
1321 recursion in the regex matching; (c) add a paragraph to the documentation
1322 for the FullMatch() function.
1323
1324 6. The escape sequence \n was being treated as whatever was defined as
1325 "newline". Not only was this contrary to the documentation, which states
1326 that \n is character 10 (hex 0A), but it also went horribly wrong when
1327 "newline" was defined as CRLF. This has been fixed.
1328
1329 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1330 was being set to -1 for the "end of line" case (supposedly a value that no
1331 character can have). Though this value is never used (the check for end of
1332 line is "zero bytes in current character"), it caused compiler complaints.
1333 I've changed it to 0xffffffff.
1334
1335 8. In pcre_version.c, the version string was being built by a sequence of
1336 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1337 string (as it is for production releases) called a macro with an empty
1338 argument. The C standard says the result of this is undefined. The gcc
1339 compiler treats it as an empty string (which was what was wanted) but it is
1340 reported that Visual C gives an error. The source has been hacked around to
1341 avoid this problem.
1342
1343 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1344 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1345 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1346 of them did).
1347
1348 10. Originally, pcretest opened its input and output without "b"; then I was
1349 told that "b" was needed in some environments, so it was added for release
1350 5.0 to both the input and output. (It makes no difference on Unix-like
1351 systems.) Later I was told that it is wrong for the input on Windows. I've
1352 now abstracted the modes into two macros, to make it easier to fiddle with
1353 them, and removed "b" from the input mode under Windows.
1354
1355 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1356
1357 12. Added -help and --help to pcretest as an official way of being reminded
1358 of the options.
1359
1360 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1361 and pcrecpp.cc because they annoy compilers at high warning levels.
1362
1363 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1364
1365 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1366 scripts are not C programs :-) and which was not noticed because it works
1367 on Linux.
1368
1369 16. pcretest is supposed to handle any length of pattern and data line (as one
1370 line or as a continued sequence of lines) by extending its input buffer if
1371 necessary. This feature was broken for very long pattern lines, leading to
1372 a string of junk being passed to pcre_compile() if the pattern was longer
1373 than about 50K.
1374
1375 17. I have done a major re-factoring of the way pcre_compile() computes the
1376 amount of memory needed for a compiled pattern. Previously, there was code
1377 that made a preliminary scan of the pattern in order to do this. That was
1378 OK when PCRE was new, but as the facilities have expanded, it has become
1379 harder and harder to keep it in step with the real compile phase, and there
1380 have been a number of bugs (see for example, 4 above). I have now found a
1381 cunning way of running the real compile function in a "fake" mode that
1382 enables it to compute how much memory it would need, while actually only
1383 ever using a few hundred bytes of working memory and without too many
1384 tests of the mode. This should make future maintenance and development
1385 easier. A side effect of this work is that the limit of 200 on the nesting
1386 depth of parentheses has been removed (though this was never a serious
1387 limitation, I suspect). However, there is a downside: pcre_compile() now
1388 runs more slowly than before (30% or more, depending on the pattern). I
1389 hope this isn't a big issue. There is no effect on runtime performance.
1390
1391 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1392 newline (only possible for the last line of a file) and it was a
1393 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1394
1395 19. Added additional timing features to pcretest. (1) The -tm option now times
1396 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1397 separate command line item, by a number that specifies the number of
1398 repeats to use when timing. The default is 50000; this gives better
1399 precision, but takes uncomfortably long for very large patterns.
1400
1401 20. Extended pcre_study() to be more clever in cases where a branch of a
1402 subpattern has no definite first character. For example, (a*|b*)[cd] would
1403 previously give no result from pcre_study(). Now it recognizes that the
1404 first character must be a, b, c, or d.
1405
1406 21. There was an incorrect error "recursive call could loop indefinitely" if
1407 a subpattern (or the entire pattern) that was being tested for matching an
1408 empty string contained only one non-empty item after a nested subpattern.
1409 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1410 incorrectly, because the \d was being skipped in the check.
1411
1412 22. The pcretest program now has a new pattern option /B and a command line
1413 option -b, which is equivalent to adding /B to every pattern. This causes
1414 it to show the compiled bytecode, without the additional information that
1415 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1416 is the same as /B/I).
1417
1418 23. A new optimization is now able automatically to treat some sequences such
1419 as a*b as a*+b. More specifically, if something simple (such as a character
1420 or a simple class like \d) has an unlimited quantifier, and is followed by
1421 something that cannot possibly match the quantified thing, the quantifier
1422 is automatically "possessified".
1423
1424 24. A recursive reference to a subpattern whose number was greater than 39
1425 went wrong under certain circumstances in UTF-8 mode. This bug could also
1426 have affected the operation of pcre_study().
1427
1428 25. Realized that a little bit of performance could be had by replacing
1429 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1430
1431 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1432
1433 27. Possessive quantifiers such as a++ were previously implemented by turning
1434 them into atomic groups such as ($>a+). Now they have their own opcodes,
1435 which improves performance. This includes the automatically created ones
1436 from 23 above.
1437
1438 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1439 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1440 the first matched character to be a colon. This applied both to named and
1441 numbered groups.
1442
1443 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1444
1445 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1446 building PCRE on Windows easier, so I have included it in the distribution.
1447
1448 31. There is now a check in pcretest against a ridiculously large number being
1449 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1450 loop, the loop is abandoned.
1451
1452 32. Forward references to subpatterns in conditions such as (?(2)...) where
1453 subpattern 2 is defined later cause pcre_compile() to search forwards in
1454 the pattern for the relevant set of parentheses. This search went wrong
1455 when there were unescaped parentheses in a character class, parentheses
1456 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1457
1458 33. "Subroutine" calls and backreferences were previously restricted to
1459 referencing subpatterns earlier in the regex. This restriction has now
1460 been removed.
1461
1462 34. Added a number of extra features that are going to be in Perl 5.10. On the
1463 whole, these are just syntactic alternatives for features that PCRE had
1464 previously implemented using the Python syntax or my own invention. The
1465 other formats are all retained for compatibility.
1466
1467 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1468 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1469 also .NET compatible.
1470
1471 (b) A recursion or subroutine call to a named group can now be defined as
1472 (?&name) as well as (?P>name).
1473
1474 (c) A backreference to a named group can now be defined as \k<name> or
1475 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1476 5.10, are also .NET compatible.
1477
1478 (d) A conditional reference to a named group can now use the syntax
1479 (?(<name>) or (?('name') as well as (?(name).
1480
1481 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1482 groups (named and numbered) that are never evaluated inline, but can be
1483 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1484 is always false. There may be only one alternative in such a group.
1485
1486 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1487 as the simple (?(R). The condition is true only if the most recent
1488 recursion is that of the given number or name. It does not search out
1489 through the entire recursion stack.
1490
1491 (g) The escape \gN or \g{N} has been added, where N is a positive or
1492 negative number, specifying an absolute or relative reference.
1493
1494 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1495 some "unreachable code" warnings.
1496
1497 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1498 things, this adds five new scripts.
1499
1500 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1501 There were also incompatibilities regarding the handling of \Q..\E inside
1502 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1503 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1504
1505 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1506 matches an empty string, and forcibly breaks the loop. There were bugs in
1507 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1508 against aaaa the result was just "a" rather than "aaaa", for example. Two
1509 separate and independent bugs (that affected different cases) have been
1510 fixed.
1511
1512 39. Refactored the code to abolish the use of different opcodes for small
1513 capturing bracket numbers. This is a tidy that I avoided doing when I
1514 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1515 The new approach is not only tidier, it makes it possible to reduce the
1516 memory needed to fix the previous bug (38).
1517
1518 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1519 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1520 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1521 mode.
1522
1523 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1524 report.
1525
1526 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1527 copy construction and assignment in the C++ wrapper.
1528
1529 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1530 couple of bugs that could have given wrong results in the "--newline=crlf"
1531 case.
1532
1533 44. Added a number of casts and did some reorganization of signed/unsigned int
1534 variables following suggestions from Dair Grant. Also renamed the variable
1535 "this" as "item" because it is a C++ keyword.
1536
1537 45. Arranged for dftables to add
1538
1539 #include "pcre_internal.h"
1540
1541 to pcre_chartables.c because without it, gcc 4.x may remove the array
1542 definition from the final binary if PCRE is built into a static library and
1543 dead code stripping is activated.
1544
1545 46. For an unanchored pattern, if a match attempt fails at the start of a
1546 newline sequence, and the newline setting is CRLF or ANY, and the next two
1547 characters are CRLF, advance by two characters instead of one.
1548
1549
1550 Version 6.7 04-Jul-06
1551 ---------------------
1552
1553 1. In order to handle tests when input lines are enormously long, pcretest has
1554 been re-factored so that it automatically extends its buffers when
1555 necessary. The code is crude, but this _is_ just a test program. The
1556 default size has been increased from 32K to 50K.
1557
1558 2. The code in pcre_study() was using the value of the re argument before
1559 testing it for NULL. (Of course, in any sensible call of the function, it
1560 won't be NULL.)
1561
1562 3. The memmove() emulation function in pcre_internal.h, which is used on
1563 systems that lack both memmove() and bcopy() - that is, hardly ever -
1564 was missing a "static" storage class specifier.
1565
1566 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1567 containing an extended class (one that cannot be represented by a bitmap
1568 because it contains high-valued characters or Unicode property items, e.g.
1569 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1570 pattern, but PCRE should not loop if you do not (it no longer does).
1571 [Detail: two cases were found: (a) a repeated subpattern containing an
1572 extended class; (b) a recursive reference to a subpattern that followed a
1573 previous extended class. It wasn't skipping over the extended class
1574 correctly when UTF-8 mode was not set.]
1575
1576 5. A negated single-character class was not being recognized as fixed-length
1577 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1578 compile error "lookbehind assertion is not fixed length".
1579
1580 6. The RunPerlTest auxiliary script was showing an unexpected difference
1581 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1582 write a Perl script that can interpret lines of an input file either as
1583 byte characters or as UTF-8, which is what "perltest" was being required to
1584 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1585 can't do is switch easily at run time between having the "use utf8;" pragma
1586 or not. In the end, I fudged it by using the RunPerlTest script to insert
1587 "use utf8;" explicitly for the UTF-8 tests.
1588
1589 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1590 the end of the subject string, contrary to the documentation and to what
1591 Perl does. This was true of both matching functions. Now it matches only at
1592 the start of the subject and immediately after *internal* newlines.
1593
1594 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1595 a pointer to an int instead of a pointer to an unsigned long int. This
1596 caused problems on 64-bit systems.
1597
1598 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1599 instance of the 'standard' template library not being so standard".
1600
1601 10. There was no check on the number of named subpatterns nor the maximum
1602 length of a subpattern name. The product of these values is used to compute
1603 the size of the memory block for a compiled pattern. By supplying a very
1604 long subpattern name and a large number of named subpatterns, the size
1605 computation could be caused to overflow. This is now prevented by limiting
1606 the length of names to 32 characters, and the number of named subpatterns
1607 to 10,000.
1608
1609 11. Subpatterns that are repeated with specific counts have to be replicated in
1610 the compiled pattern. The size of memory for this was computed from the
1611 length of the subpattern and the repeat count. The latter is limited to
1612 65535, but there was no limit on the former, meaning that integer overflow
1613 could in principle occur. The compiled length of a repeated subpattern is
1614 now limited to 30,000 bytes in order to prevent this.
1615
1616 12. Added the optional facility to have named substrings with the same name.
1617
1618 13. Added the ability to use a named substring as a condition, using the
1619 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1620 are numbers (not recommended). Forward references are permitted.
1621
1622 14. Added forward references in named backreferences (if you see what I mean).
1623
1624 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1625 pattern could run off the end of the subject. For example, the pattern
1626 "(?s)(.{1,5})"8 did this with the subject "ab".
1627
1628 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1629 PCRE_CASELESS was set when matching characters that were quantified with ?
1630 or *.
1631
1632 17. A character class other than a single negated character that had a minimum
1633 but no maximum quantifier - for example [ab]{6,} - was not handled
1634 correctly by pce_dfa_exec(). It would match only one character.
1635
1636 18. A valid (though odd) pattern that looked like a POSIX character
1637 class but used an invalid character after [ (for example [[,abc,]]) caused
1638 pcre_compile() to give the error "Failed: internal error: code overflow" or
1639 in some cases to crash with a glibc free() error. This could even happen if
1640 the pattern terminated after [[ but there just happened to be a sequence of
1641 letters, a binary zero, and a closing ] in the memory that followed.
1642
1643 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1644 over the years. Originally (before any Unicode support), just the bottom 8
1645 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1646 output from "man perlunicode" includes this:
1647
1648 The regular expression compiler produces polymorphic opcodes. That
1649 is, the pattern adapts to the data and automatically switches to
1650 the Unicode character scheme when presented with Unicode data--or
1651 instead uses a traditional byte scheme when presented with byte
1652 data.
1653
1654 Sadly, a wide octal escape does not cause a switch, and in a string with
1655 no other multibyte characters, these octal escapes are treated as before.
1656 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1657 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1658 Unicode string.
1659
1660 I have not perpetrated such confusion in PCRE. Up till now, it took just
1661 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1662 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1663 translate to the appropriate multibyte character.
1664
1665 29. Applied some refactoring to reduce the number of warnings from Microsoft
1666 and Borland compilers. This has included removing the fudge introduced
1667 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1668 a warning about an unused variable.
1669
1670 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1671 characters since release 4.0, because Perl (from release 5.004) does not.
1672 [Or at least, is documented not to: some releases seem to be in conflict
1673 with the documentation.] However, when a pattern was studied with
1674 pcre_study() and all its branches started with \s, PCRE still included VT
1675 as a possible starting character. Of course, this did no harm; it just
1676 caused an unnecessary match attempt.
1677
1678 22. Removed a now-redundant internal flag bit that recorded the fact that case
1679 dependency changed within the pattern. This was once needed for "required
1680 byte" processing, but is no longer used. This recovers a now-scarce options
1681 bit. Also moved the least significant internal flag bit to the most-
1682 significant bit of the word, which was not previously used (hangover from
1683 the days when it was an int rather than a uint) to free up another bit for
1684 the future.
1685
1686 23. Added support for CRLF line endings as well as CR and LF. As well as the
1687 default being selectable at build time, it can now be changed at runtime
1688 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1689 specify that it is scanning data with non-default line endings.
1690
1691 24. Changed the definition of CXXLINK to make it agree with the definition of
1692 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1693
1694 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1695 recursions. This makes a big different to stack usage for some patterns.
1696
1697 26. If a subpattern containing a named recursion or subroutine reference such
1698 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1699 the space required for the compiled pattern went wrong and gave too small a
1700 value. Depending on the environment, this could lead to "Failed: internal
1701 error: code overflow at offset 49" or "glibc detected double free or
1702 corruption" errors.
1703
1704 27. Applied patches from Google (a) to support the new newline modes and (b) to
1705 advance over multibyte UTF-8 characters in GlobalReplace.
1706
1707 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1708 difference for some implementation of PCRE in some Windows version.
1709
1710 29. Added some extra testing facilities to pcretest:
1711
1712 \q<number> in a data line sets the "match limit" value
1713 \Q<number> in a data line sets the "match recursion limt" value
1714 -S <number> sets the stack size, where <number> is in megabytes
1715
1716 The -S option isn't available for Windows.
1717
1718
1719 Version 6.6 06-Feb-06
1720 ---------------------
1721
1722 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1723 in pcreposix.h. I have copied the definition from pcre.h.
1724
1725 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1726 because pcre.h is no longer a built file.
1727
1728 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1729 not normally included in the compiled code.
1730
1731
1732 Version 6.5 01-Feb-06
1733 ---------------------
1734
1735 1. When using the partial match feature with pcre_dfa_exec(), it was not
1736 anchoring the second and subsequent partial matches at the new starting
1737 point. This could lead to incorrect results. For example, with the pattern
1738 /1234/, partially matching against "123" and then "a4" gave a match.
1739
1740 2. Changes to pcregrep:
1741
1742 (a) All non-match returns from pcre_exec() were being treated as failures
1743 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1744 error message is output. Some extra information is given for the
1745 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1746 probably the only errors that are likely to be caused by users (by
1747 specifying a regex that has nested indefinite repeats, for instance).
1748 If there are more than 20 of these errors, pcregrep is abandoned.
1749
1750 (b) A binary zero was treated as data while matching, but terminated the
1751 output line if it was written out. This has been fixed: binary zeroes
1752 are now no different to any other data bytes.
1753
1754 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1755 used to set a locale for matching. The --locale=xxxx long option has
1756 been added (no short equivalent) to specify a locale explicitly on the
1757 pcregrep command, overriding the environment variables.
1758
1759 (d) When -B was used with -n, some line numbers in the output were one less
1760 than they should have been.
1761
1762 (e) Added the -o (--only-matching) option.
1763
1764 (f) If -A or -C was used with -c (count only), some lines of context were
1765 accidentally printed for the final match.
1766
1767 (g) Added the -H (--with-filename) option.
1768
1769 (h) The combination of options -rh failed to suppress file names for files
1770 that were found from directory arguments.
1771
1772 (i) Added the -D (--devices) and -d (--directories) options.
1773
1774 (j) Added the -F (--fixed-strings) option.
1775
1776 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1777
1778 (l) Added the --colo(u)r option.
1779
1780 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1781 is not present by default.
1782
1783 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1784 items such as (?R) or (?1), when the recursion could match a number of
1785 alternatives. If it matched one of the alternatives, but subsequently,
1786 outside the recursion, there was a failure, the code tried to back up into
1787 the recursion. However, because of the way PCRE is implemented, this is not
1788 possible, and the result was an incorrect result from the match.
1789
1790 In order to prevent this happening, the specification of recursion has
1791 been changed so that all such subpatterns are automatically treated as
1792 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1793
1794 4. I had overlooked the fact that, in some locales, there are characters for
1795 which isalpha() is true but neither isupper() nor islower() are true. In
1796 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1797 and ordfeminine) are like this. This affected the treatment of \w and \W
1798 when they appeared in character classes, but not when they appeared outside
1799 a character class. The bit map for "word" characters is now created
1800 separately from the results of isalnum() instead of just taking it from the
1801 upper, lower, and digit maps. (Plus the underscore character, of course.)
1802
1803 5. The above bug also affected the handling of POSIX character classes such as
1804 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1805 permanent tables. Instead, the bit maps for such a class were previously
1806 created as the appropriate unions of the upper, lower, and digit bitmaps.
1807 Now they are created by subtraction from the [[:word:]] class, which has
1808 its own bitmap.
1809
1810 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1811 It is created by subtracting the vertical space characters (\x09, \x0a,
1812 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1813 subtraction was done in the overall bitmap for a character class, meaning
1814 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1815 be recognized. This bug has been fixed.
1816
1817 7. Patches from the folks at Google:
1818
1819 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1820 real life, but is still worth protecting against".
1821
1822 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1823 regular expressions".
1824
1825 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1826 have it.
1827
1828 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1829 "configure" and the latter not, in order to fix a problem somebody had
1830 with compiling the Arg class on HP-UX.
1831
1832 (e) Improve the error-handling of the C++ wrapper a little bit.
1833
1834 (f) New tests for checking recursion limiting.
1835
1836 8. The pcre_memmove() function, which is used only if the environment does not
1837 have a standard memmove() function (and is therefore rarely compiled),
1838 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1839 returning a result (though PCRE never actually uses the result).
1840
1841 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1842 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1843 returned instead of calling malloc() with an overflowing number that would
1844 most likely cause subsequent chaos.
1845
1846 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1847
1848 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1849 with this option is matched, the nmatch and pmatch options of regexec() are
1850 ignored.
1851
1852 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1853 provided in case anyone wants to the the POSIX interface with UTF-8
1854 strings.
1855
1856 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1857 C++ linking (needed for some HP-UX environments).
1858
1859 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1860 (unused parameter) and in the pcre_printint() function (omitted "default"
1861 switch label when the default is to do nothing).
1862
1863 15. Added some code to make it possible, when PCRE is compiled as a C++
1864 library, to replace subject pointers for pcre_exec() with a smart pointer
1865 class, thus making it possible to process discontinuous strings.
1866
1867 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1868 much the same function. They were added by different people who were trying
1869 to make PCRE easy to compile on non-Unix systems. It has been suggested
1870 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1871 for compiling on Windows systems. I have therefore replaced it with
1872 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1873 defaults to "extern" for C or "extern C" for C++, which works fine on
1874 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1875 SCOPE with something explicit in config.h. In addition:
1876
1877 (a) pcreposix.h still had just "extern" instead of either of these macros;
1878 I have replaced it with PCRE_DATA_SCOPE.
1879
1880 (b) Functions such as _pcre_xclass(), which are internal to the library,
1881 but external in the C sense, all had PCRE_EXPORT in their definitions.
1882 This is apparently wrong for the Windows case, so I have removed it.
1883 (It makes no difference on Unix-like systems.)
1884
1885 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1886 of recursive calls to match(). This is different to MATCH_LIMIT because
1887 that limits the total number of calls to match(), not all of which increase
1888 the depth of recursion. Limiting the recursion depth limits the amount of
1889 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1890 when PCRE is compiled, and changed at run time. A patch from Google adds
1891 this functionality to the C++ interface.
1892
1893 18. Changes to the handling of Unicode character properties:
1894
1895 (a) Updated the table to Unicode 4.1.0.
1896
1897 (b) Recognize characters that are not in the table as "Cn" (undefined).
1898
1899 (c) I revised the way the table is implemented to a much improved format
1900 which includes recognition of ranges. It now supports the ranges that
1901 are defined in UnicodeData.txt, and it also amalgamates other
1902 characters into ranges. This has reduced the number of entries in the
1903 table from around 16,000 to around 3,000, thus reducing its size
1904 considerably. I realized I did not need to use a tree structure after
1905 all - a binary chop search is just as efficient. Having reduced the
1906 number of entries, I extended their size from 6 bytes to 8 bytes to
1907 allow for more data.
1908
1909 (d) Added support for Unicode script names via properties such as \p{Han}.
1910
1911 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1912 matching that character.
1913
1914 20. When matching a repeated Unicode property with a minimum greater than zero,
1915 (for example \pL{2,}), PCRE could look past the end of the subject if it
1916 reached it while seeking the minimum number of characters. This could
1917 happen only if some of the characters were more than one byte long, because
1918 there is a check for at least the minimum number of bytes.
1919
1920 21. Refactored the implementation of \p and \P so as to be more general, to
1921 allow for more different types of property in future. This has changed the
1922 compiled form incompatibly. Anybody with saved compiled patterns that use
1923 \p or \P will have to recompile them.
1924
1925 22. Added "Any" and "L&" to the supported property types.
1926
1927 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1928 but give a compile time error if the value is greater than 0xff.
1929
1930 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1931 accidentally not being installed or uninstalled.
1932
1933 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1934 made were to insert the current release number. This seemed silly, because
1935 it made things harder for people building PCRE on systems that don't run
1936 "configure". I have turned pcre.h into a distributed file, no longer built
1937 by "configure", with the version identification directly included. There is
1938 no longer a pcre.h.in file.
1939
1940 However, this change necessitated a change to the pcre-config script as
1941 well. It is built from pcre-config.in, and one of the substitutions was the
1942 release number. I have updated configure.ac so that ./configure now finds
1943 the release number by grepping pcre.h.
1944
1945 26. Added the ability to run the tests under valgrind.
1946
1947
1948 Version 6.4 05-Sep-05
1949 ---------------------
1950
1951 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1952 "--" to be printed when multiple files were scanned, even when none of the
1953 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1954 consider it to be a bug, and have restored the previous behaviour.
1955
1956 2. A couple of code tidies to get rid of compiler warnings.
1957
1958 3. The pcretest program used to cheat by referring to symbols in the library
1959 whose names begin with _pcre_. These are internal symbols that are not
1960 really supposed to be visible externally, and in some environments it is
1961 possible to suppress them. The cheating is now confined to including
1962 certain files from the library's source, which is a bit cleaner.
1963
1964 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1965 file's purpose clearer.
1966
1967 5. Reorganized pcre_ucp_findchar().
1968
1969
1970 Version 6.3 15-Aug-05
1971 ---------------------
1972
1973 1. The file libpcre.pc.in did not have general read permission in the tarball.
1974
1975 2. There were some problems when building without C++ support:
1976
1977 (a) If C++ support was not built, "make install" and "make test" still
1978 tried to test it.
1979
1980 (b) There were problems when the value of CXX was explicitly set. Some
1981 changes have been made to try to fix these, and ...
1982
1983 (c) --disable-cpp can now be used to explicitly disable C++ support.
1984
1985 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1986 backslash in a target when C++ was disabled. This confuses some
1987 versions of "make", apparently. Using an intermediate variable solves
1988 this. (Same for CPP_LOBJ.)
1989
1990 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1991 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1992 necessary on certain architectures.
1993
1994 4. Added a setting of -export-symbols-regex to the link command to remove
1995 those symbols that are exported in the C sense, but actually are local
1996 within the library, and not documented. Their names all begin with
1997 "_pcre_". This is not a perfect job, because (a) we have to except some
1998 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1999 available (and never for static libraries). I have made a note to try to
2000 find a way round (a) in the future.
2001
2002
2003 Version 6.2 01-Aug-05
2004 ---------------------
2005
2006 1. There was no test for integer overflow of quantifier values. A construction
2007 such as {1111111111111111} would give undefined results. What is worse, if
2008 a minimum quantifier for a parenthesized subpattern overflowed and became
2009 negative, the calculation of the memory size went wrong. This could have
2010 led to memory overwriting.
2011
2012 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2013
2014 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2015 operating environments where this matters.
2016
2017 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2018 PCRE options from within the C++ wrapper.
2019
2020 5. Named capturing subpatterns were not being correctly counted when a pattern
2021 was compiled. This caused two problems: (a) If there were more than 100
2022 such subpatterns, the calculation of the memory needed for the whole
2023 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2024 back references of the form \12, where the number was greater than 9, were
2025 not recognized as back references, even though there were sufficient
2026 previous subpatterns.
2027
2028 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2029 versions of gcc, e.g. 2.95.4.
2030
2031
2032 Version 6.1 21-Jun-05
2033 ---------------------
2034
2035 1. There was one reference to the variable "posix" in pcretest.c that was not
2036 surrounded by "#if !defined NOPOSIX".
2037
2038 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2039 the cross-check on the old pcre_info() function, for the benefit of the
2040 cut-down version of PCRE that is currently imported into Exim.
2041
2042 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2043 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2044 patterns that start (?i) but I don't think that matters. The use of (?i) is
2045 just an example; this all applies to the other options as well.
2046
2047 4. Since libtool seems to echo the compile commands it is issuing, the output
2048 from "make" can be reduced a bit by putting "@" in front of each libtool
2049 compile command.
2050
2051 5. Patch from the folks at Google for configure.in to be a bit more thorough
2052 in checking for a suitable C++ installation before trying to compile the
2053 C++ stuff. This should fix a reported problem when a compiler was present,
2054 but no suitable headers.
2055
2056 6. The man pages all had just "PCRE" as their title. I have changed them to
2057 be the relevant file name. I have also arranged that these names are
2058 retained in the file doc/pcre.txt, which is a concatenation in text format
2059 of all the man pages except the little individual ones for each function.
2060
2061 7. The NON-UNIX-USE file had not been updated for the different set of source
2062 files that come with release 6. I also added a few comments about the C++
2063 wrapper.
2064
2065
2066 Version 6.0 07-Jun-05
2067 ---------------------
2068
2069 1. Some minor internal re-organization to help with my DFA experiments.
2070
2071 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2072 didn't matter for the library itself when fully configured, but did matter
2073 when compiling without UCP support, or within Exim, where the ucp files are
2074 not imported.
2075
2076 3. Refactoring of the library code to split up the various functions into
2077 different source modules. The addition of the new DFA matching code (see
2078 below) to a single monolithic source would have made it really too
2079 unwieldy, quite apart from causing all the code to be include in a
2080 statically linked application, when only some functions are used. This is
2081 relevant even without the DFA addition now that patterns can be compiled in
2082 one application and matched in another.
2083
2084 The downside of splitting up is that there have to be some external
2085 functions and data tables that are used internally in different modules of
2086 the library but which are not part of the API. These have all had their
2087 names changed to start with "_pcre_" so that they are unlikely to clash
2088 with other external names.
2089
2090 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2091 a different (DFA) algorithm. Although it is slower than the original
2092 function, it does have some advantages for certain types of matching
2093 problem.
2094
2095 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2096 including restarting after a partial match.
2097
2098 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2099 defined when compiling for Windows was sent to me. I have put it into the
2100 code, though I have no means of testing or verifying it.
2101
2102 7. Added the pcre_refcount() auxiliary function.
2103
2104 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2105 match before or at the first newline in the subject string. In pcretest,
2106 the /f option on a pattern can be used to set this.
2107
2108 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2109 would behave wrongly. This has been present in PCRE since release 4.0.
2110
2111 10. A number of changes to the pcregrep command:
2112
2113 (a) Refactored how -x works; insert ^(...)$ instead of setting
2114 PCRE_ANCHORED and checking the length, in preparation for adding
2115 something similar for -w.
2116
2117 (b) Added the -w (match as a word) option.
2118
2119 (c) Refactored the way lines are read and buffered so as to have more
2120 than one at a time available.
2121
2122 (d) Implemented a pcregrep test script.
2123
2124 (e) Added the -M (multiline match) option. This allows patterns to match
2125 over several lines of the subject. The buffering ensures that at least
2126 8K, or the rest of the document (whichever is the shorter) is available
2127 for matching (and similarly the previous 8K for lookbehind assertions).
2128
2129 (f) Changed the --help output so that it now says
2130
2131 -w, --word-regex(p)
2132
2133 instead of two lines, one with "regex" and the other with "regexp"
2134 because that confused at least one person since the short forms are the
2135 same. (This required a bit of code, as the output is generated
2136 automatically from a table. It wasn't just a text change.)
2137
2138 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2139 option but starts with a hyphen. Could be a pattern or a path name
2140 starting with a hyphen, for instance.
2141
2142 (h) "-" can be given as a file name to represent stdin.
2143
2144 (i) When file names are being printed, "(standard input)" is used for
2145 the standard input, for compatibility with GNU grep. Previously
2146 "<stdin>" was used.
2147
2148 (j) The option --label=xxx can be used to supply a name to be used for
2149 stdin when file names are being printed. There is no short form.
2150
2151 (k) Re-factored the options decoding logic because we are going to add
2152 two more options that take data. Such options can now be given in four
2153 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2154
2155 (l) Added the -A, -B, and -C options for requesting that lines of context
2156 around matches be printed.
2157
2158 (m) Added the -L option to print the names of files that do not contain
2159 any matching lines, that is, the complement of -l.
2160
2161 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2162 continue to scan other files.
2163
2164 (o) The -s option was incorrectly implemented. For compatibility with other
2165 greps, it now suppresses the error message for a non-existent or non-
2166 accessible file (but not the return code). There is a new option called
2167 -q that suppresses the output of matching lines, which was what -s was
2168 previously doing.
2169
2170 (p) Added --include and --exclude options to specify files for inclusion
2171 and exclusion when recursing.
2172
2173 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2174 Hopefully, it now does.
2175
2176 12. Missing cast in pcre_study().
2177
2178 13. Added an "uninstall" target to the makefile.
2179
2180 14. Replaced "extern" in the function prototypes in Makefile.in with
2181 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2182 world, but is set differently for Windows.
2183
2184 15. Added a second compiling function called pcre_compile2(). The only
2185 difference is that it has an extra argument, which is a pointer to an
2186 integer error code. When there is a compile-time failure, this is set
2187 non-zero, in addition to the error test pointer being set to point to an
2188 error message. The new argument may be NULL if no error number is required
2189 (but then you may as well call pcre_compile(), which is now just a
2190 wrapper). This facility is provided because some applications need a
2191 numeric error indication, but it has also enabled me to tidy up the way
2192 compile-time errors are handled in the POSIX wrapper.
2193
2194 16. Added VPATH=.libs to the makefile; this should help when building with one
2195 prefix path and installing with another. (Or so I'm told by someone who
2196 knows more about this stuff than I do.)
2197
2198 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2199 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2200 match everything, including newlines. This is not POSIX-compatible, but
2201 somebody wanted the feature. From pcretest it can be activated by using
2202 both the P and the s flags.
2203
2204 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2205
2206 19. libpcre.pc was being incorrectly installed as executable.
2207
2208 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2209 it now also looks for '\r' so that it will work unmodified on Windows.
2210
2211 21. Added Google's contributed C++ wrapper to the distribution.
2212
2213 22. Added some untidy missing memory free() calls in pcretest, to keep
2214 Electric Fence happy when testing.
2215
2216
2217
2218 Version 5.0 13-Sep-04
2219 ---------------------
2220
2221 1. Internal change: literal characters are no longer packed up into items
2222 containing multiple characters in a single byte-string. Each character
2223 is now matched using a separate opcode. However, there may be more than one
2224 byte in the character in UTF-8 mode.
2225
2226 2. The pcre_callout_block structure has two new fields: pattern_position and
2227 next_item_length. These contain the offset in the pattern to the next match
2228 item, and its length, respectively.
2229
2230 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2231 insertion of callouts before each pattern item. Added the /C option to
2232 pcretest to make use of this.
2233
2234 4. On the advice of a Windows user, the lines
2235
2236 #if defined(_WIN32) || defined(WIN32)
2237 _setmode( _fileno( stdout ), 0x8000 );
2238 #endif /* defined(_WIN32) || defined(WIN32) */
2239
2240 have been added to the source of pcretest. This apparently does useful
2241 magic in relation to line terminators.
2242
2243 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2244 for the benefit of those environments where the "b" makes a difference.
2245
2246 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2247 to know about it. I have put a hack into configure.in that adds in code
2248 to set GCC=yes if CC=icc. This seems to end up at a point in the
2249 generated configure script that is early enough to affect the setting of
2250 compiler options, which is what is needed, but I have no means of testing
2251 whether it really works. (The user who reported this had patched the
2252 generated configure script, which of course I cannot do.)
2253
2254 LATER: After change 22 below (new libtool files), the configure script
2255 seems to know about icc (and also ecc). Therefore, I have commented out
2256 this hack in configure.in.
2257
2258 7. Added support for pkg-config (2 patches were sent in).
2259
2260 8. Negated POSIX character classes that used a combination of internal tables
2261 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2262 [[:^ascii]]. Typically, they would match almost any characters. The other
2263 POSIX classes were not broken in this way.
2264
2265 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2266 to find the match, as PCRE was deluded into thinking that the match had to
2267 start at the start point or following a newline. The same bug applied to
2268 patterns with negative forward assertions or any backward assertions
2269 preceding ".*" at the start, unless the pattern required a fixed first
2270 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2271
2272 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2273 starting at the last subject character, bytes beyond the end of the subject
2274 string were read.
2275
2276 11. Renamed the variable "class" as "classbits" to make life easier for C++
2277 users. (Previously there was a macro definition, but it apparently wasn't
2278 enough.)
2279
2280 12. Added the new field "tables" to the extra data so that tables can be passed
2281 in at exec time, or the internal tables can be re-selected. This allows
2282 a compiled regex to be saved and re-used at a later time by a different
2283 program that might have everything at different addresses.
2284
2285 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2286 -R library as well as a -L library.
2287
2288 14. The debugging options of pcretest (-d on the command line or D on a
2289 pattern) showed incorrect output for anything following an extended class
2290 that contained multibyte characters and which was followed by a quantifier.
2291
2292 15. Added optional support for general category Unicode character properties
2293 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2294 support. It adds about 90K to the size of the library. The meanings of the
2295 inbuilt class escapes such as \d and \s have NOT been changed.
2296
2297 16. Updated pcredemo.c to include calls to free() to release the memory for the
2298 compiled pattern.
2299
2300 17. The generated file chartables.c was being created in the source directory
2301 instead of in the building directory. This caused the build to fail if the
2302 source directory was different from the building directory, and was
2303 read-only.
2304
2305 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2306 file. No doubt somebody will tell me if they don't make sense... Also added
2307 Dan Mooney's comments about building on OpenVMS.
2308
2309 19. Added support for partial matching via the PCRE_PARTIAL option for
2310 pcre_exec() and the \P data escape in pcretest.
2311
2312 20. Extended pcretest with 3 new pattern features:
2313
2314 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2315 write the compiled pattern to the file whose name is "rest-of-line".
2316 This is a straight binary dump of the data, with the saved pointer to
2317 the character tables forced to be NULL. The study data, if any, is
2318 written too. After writing, pcretest reads a new pattern.
2319
2320 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2321 compiled pattern from the given file. There must not be any
2322 occurrences of "<" in the file name (pretty unlikely); if there are,
2323 pcretest will instead treat the initial "<" as a pattern delimiter.
2324 After reading in the pattern, pcretest goes on to read data lines as
2325 usual.
2326
2327 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2328 and 16-bit fields in a compiled pattern, to simulate a pattern that
2329 was compiled on a host of opposite endianness.
2330
2331 21. The pcre-exec() function can now cope with patterns that were compiled on
2332 hosts of opposite endianness, with this restriction:
2333
2334 As for any compiled expression that is saved and used later, the tables
2335 pointer field cannot be preserved; the extra_data field in the arguments
2336 to pcre_exec() should be used to pass in a tables address if a value
2337 other than the default internal tables were used at compile time.
2338
2339 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2340 now diagnosed as an error. Previously, most of the time, a negative number
2341 would have been treated as zero, but if in addition "ovector" was passed as
2342 NULL, a crash could occur.
2343
2344 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2345 new versions from the libtool 1.5 distribution (the last one is a copy of
2346 a file called libtool.m4). This seems to have fixed the need to patch
2347 "configure" to support Darwin 1.3 (which I used to do). However, I still
2348 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2349 workstation).
2350
2351 24. Changed the PCRE licence to be the more standard "BSD" licence.
2352
2353
2354 Version 4.5 01-Dec-03
2355 ---------------------
2356
2357 1. There has been some re-arrangement of the code for the match() function so
2358 that it can be compiled in a version that does not call itself recursively.
2359 Instead, it keeps those local variables that need separate instances for
2360 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2361 needs to "recurse". Keeping track of where control must go is done by means
2362 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2363 hide most of the details from the main code, and operates only if
2364 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2365 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2366 operating.
2367
2368 To make it easier for callers to provide specially tailored get/free
2369 functions for this usage, two new functions, pcre_stack_malloc, and
2370 pcre_stack_free, are used. They are always called in strict stacking order,
2371 and the size of block requested is always the same.
2372
2373 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2374 PCRE has been compiled to use the stack or the heap for recursion. The
2375 -C option of pcretest uses this to show which version is compiled.
2376
2377 A new data escape \S, is added to pcretest; it causes the amounts of store
2378 obtained and freed by both kinds of malloc/free at match time to be added
2379 to the output.
2380
2381 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2382 what's available on my current Linux desktop machine.
2383
2384 3. When matching a UTF-8 string, the test for a valid string at the start has
2385 been extended. If start_offset is not zero, PCRE now checks that it points
2386 to a byte that is the start of a UTF-8 character. If not, it returns
2387 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2388 this is necessary because there may be backward assertions in the pattern.
2389 When matching the same subject several times, it may save resources to use
2390 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2391
2392 4. The code for checking the validity of UTF-8 strings has been tightened so
2393 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2394 containing "overlong sequences".
2395
2396 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2397 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2398 should have been "&", but it just so happened that all the cases this let
2399 through by mistake were picked up later in the function.
2400
2401 6. I had used a variable called "isblank" - this is a C99 function, causing
2402 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2403
2404 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2405 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2406 so the version is shown; (c) stop "make test" echoing "./RunTest".
2407
2408 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2409
2410 9. The prototype for memmove() for systems that don't have it was using
2411 size_t, but the inclusion of the header that defines size_t was later. I've
2412 moved the #includes for the C headers earlier to avoid this.
2413
2414 10. Added some adjustments to the code to make it easier to compiler on certain
2415 special systems:
2416
2417 (a) Some "const" qualifiers were missing.
2418 (b) Added the macro EXPORT before all exported functions; by default this
2419 is defined to be empty.
2420 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2421 that it reads its output file name as an argument instead of writing
2422 to the standard output and assuming this can be redirected.
2423
2424 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2425 class containing characters with values greater than 255, PCRE compilation
2426 went into a loop.
2427
2428 12. A recursive reference to a subpattern that was within another subpattern
2429 that had a minimum quantifier of zero caused PCRE to crash. For example,
2430 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2431 recursion. If the recursively-called subpattern itself had a zero repeat,
2432 that was OK.
2433
2434 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2435 buffer into which it was copied (for escape processing) was still set at
2436 1024, so long lines caused crashes.
2437
2438 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2439 "internal error: code overflow...". This applied to any character class
2440 that was followed by a possessive quantifier.
2441
2442 15. Modified the Makefile to add libpcre.la as a prerequisite for
2443 libpcreposix.la because I was told this is needed for a parallel build to
2444 work.
2445
2446 16. If a pattern that contained .* following optional items at the start was
2447 studied, the wrong optimizing data was generated, leading to matching
2448 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2449 matching string must start with a or b or c. The correct conclusion for
2450 this pattern is that a match can start with any character.
2451
2452
2453 Version 4.4 13-Aug-03
2454 ---------------------
2455
2456 1. In UTF-8 mode, a character class containing characters with values between
2457 127 and 255 was not handled correctly if the compiled pattern was studied.
2458 In fixing this, I have also improved the studying algorithm for such
2459 classes (slightly).
2460
2461 2. Three internal functions had redundant arguments passed to them. Removal
2462 might give a very teeny performance improvement.
2463
2464 3. Documentation bug: the value of the capture_top field in a callout is *one
2465 more than* the number of the hightest numbered captured substring.
2466
2467 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2468 in incorrectly linking with a previously installed version. They now link
2469 explicitly with libpcre.la.
2470
2471 5. configure.in no longer needs to recognize Cygwin specially.
2472
2473 6. A problem in pcre.in for Windows platforms is fixed.
2474
2475 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2476 pcretest, it used to include the size of the study block as part of its
2477 output. Unfortunately, the structure contains a field that has a different
2478 size on different hardware architectures. This meant that the tests that
2479 showed this size failed. As the block is currently always of a fixed size,
2480 this information isn't actually particularly useful in pcretest output, so
2481 I have just removed it.
2482
2483 8. Three pre-processor statements accidentally did not start in column 1.
2484 Sadly, there are *still* compilers around that complain, even though
2485 standard C has not required this for well over a decade. Sigh.
2486
2487 9. In pcretest, the code for checking callouts passed small integers in the
2488 callout_data field, which is a void * field. However, some picky compilers
2489 complained about the casts involved for this on 64-bit systems. Now
2490 pcretest passes the address of the small integer instead, which should get
2491 rid of the warnings.
2492
2493 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2494 both compile and run time, and gives an error if an invalid UTF-8 sequence
2495 is found. There is a option for disabling this check in cases where the
2496 string is known to be correct and/or the maximum performance is wanted.
2497
2498 11. In response to a bug report, I changed one line in Makefile.in from
2499
2500 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2501 to
2502 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2503
2504 to look similar to other lines, but I have no way of telling whether this
2505 is the right thing to do, as I do not use Windows. No doubt I'll get told
2506 if it's wrong...
2507
2508
2509 Version 4.3 21-May-03
2510 ---------------------
2511
2512 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2513 Makefile.
2514
2515 2. Some refactoring to improve the quality of the code:
2516
2517 (i) The utf8_table... variables are now declared "const".
2518
2519 (ii) The code for \cx, which used the "case flipping" table to upper case
2520 lower case letters, now just substracts 32. This is ASCII-specific,
2521 but the whole concept of \cx is ASCII-specific, so it seems
2522 reasonable.
2523
2524 (iii) PCRE was using its character types table to recognize decimal and
2525 hexadecimal digits in the pattern. This is silly, because it handles
2526 only 0-9, a-f, and A-F, but the character types table is locale-
2527 specific, which means strange things might happen. A private
2528 table is now used for this - though it costs 256 bytes, a table is
2529 much faster than multiple explicit tests. Of course, the standard
2530 character types table is still used for matching digits in subject
2531 strings against \d.
2532
2533 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2534 ending in _t are). So I've renamed it as ESC_tee.
2535
2536 3. The first argument for regexec() in the POSIX wrapper should have been
2537 defined as "const".
2538
2539 4. Changed pcretest to use malloc() for its buffers so that they can be
2540 Electric Fenced for debugging.
2541
2542 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2543 to read one or more bytes before the start of the subject string. Often this
2544 had no effect on PCRE's behaviour, but in some circumstances it could
2545 provoke a segmentation fault.
2546
2547 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2548 to try to read one or more bytes before the start of the subject string.
2549
2550 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2551 UTF-8 support could misbehave in various ways if the subject string
2552 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2553 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2554 back over UTF-8 characters.)
2555
2556
2557 Version 4.2 14-Apr-03
2558 ---------------------
2559
2560 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2561
2562 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2563 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2564 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2565 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2566 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2567 and BUILD_EXEEXT
2568 Note: automatic setting of the BUILD variables is not yet working
2569 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2570 compile-time but not at link-time
2571 [LINK]: use for linking executables only
2572 make different versions for Windows and non-Windows
2573 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2574 libraries
2575 [LINK_FOR_BUILD]: new variable
2576 [OBJEXT]: use throughout
2577 [EXEEXT]: use throughout
2578 <winshared>: new target
2579 <wininstall>: new target
2580 <dftables.o>: use native compiler
2581 <dftables>: use native linker
2582 <install>: handle Windows platform correctly
2583 <clean>: ditto
2584 <check>: ditto
2585 copy DLL to top builddir before testing
2586
2587 As part of these changes, -no-undefined was removed again. This was reported
2588 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2589 in any case.
2590
2591 3. Some tidies to get rid of compiler warnings:
2592
2593 . In the match_data structure, match_limit was an unsigned long int, whereas
2594 match_call_count was an int. I've made them both unsigned long ints.
2595
2596 . In pcretest the fact that a const uschar * doesn't automatically cast to
2597 a void * provoked a warning.
2598
2599 . Turning on some more compiler warnings threw up some "shadow" variables
2600 and a few more missing casts.
2601
2602 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2603 option, a class that contained a single character with a value between 128
2604 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2605
2606 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2607 option, a class that contained several characters, but with at least one
2608 whose value was between 128 and 255 caused PCRE to crash.
2609
2610
2611 Version 4.1 12-Mar-03
2612 ---------------------
2613
2614 1. Compiling with gcc -pedantic found a couple of places where casts were
2615 needed, and a string in dftables.c that was longer than standard compilers are
2616 required to support.
2617
2618 2. Compiling with Sun's compiler found a few more places where the code could
2619 be tidied up in order to avoid warnings.
2620
2621 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2622 first of these names is deprecated in the latest Autoconf in favour of the name
2623 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2624 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2625 analogy I have changed it to CFLAGS_FOR_BUILD.
2626
2627 4. Added -no-undefined to the linking command in the Makefile, because this is
2628 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2629 linking step for the pcreposix library.
2630
2631 5. PCRE was failing to diagnose the case of two named groups with the same
2632 name.
2633
2634 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2635 literal character that is needed in the subject for a match, and scans along to
2636 ensure that it is present before embarking on the full matching process. This
2637 saves time in cases of nested unlimited repeats that are never going to match.
2638 Problem: the scan can take a lot of time if the subject is very long (e.g.
2639 megabytes), thus penalizing straightforward matches. It is now done only if the
2640 amount of subject to be scanned is less than 1000 bytes.
2641
2642 7. A lesser problem with the same optimization is that it was recording the
2643 first character of an anchored pattern as "needed", thus provoking a search
2644 right along the subject, even when the first match of the pattern was going to
2645 fail. The "needed" character is now not set for anchored patterns, unless it
2646 follows something in the pattern that is of non-fixed length. Thus, it still
2647 fulfils its original purpose of finding quick non-matches in cases of nested
2648 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2649
2650
2651 Version 4.0 17-Feb-03
2652 ---------------------
2653
2654 1. If a comment in an extended regex that started immediately after a meta-item
2655 extended to the end of string, PCRE compiled incorrect data. This could lead to
2656 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2657
2658 2. Moved to autoconf 2.53 and libtool 1.4.2.
2659
2660 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2661 the special perltest8 script is no longer needed - all the tests can be run
2662 from a single perltest script.
2663
2664 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2665 by \s. It has now been removed in PCRE. This means it isn't recognized as
2666 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2667 class [:space:] *does* include VT, thereby creating a mess.
2668
2669 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2670 space and tab.
2671
2672 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2673 its new features into the main test script, reducing the number of scripts.
2674
2675 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2676 were backward compatible, and made the (?i) apply to the whole pattern, as if
2677 /i were given. Now it behaves more logically, and applies the option setting
2678 only to what follows. PCRE has been changed to follow suit. However, if it
2679 finds options settings right at the start of the pattern, it extracts them into
2680 the global options, as before. Thus, they show up in the info data.
2681
2682 8. Added support for the \Q...\E escape sequence. Characters in between are
2683 treated as literals. This is slightly different from Perl in that $ and @ are
2684 also handled as literals inside the quotes. In Perl, they will cause variable
2685 interpolation. Note the following examples:
2686
2687 Pattern PCRE matches Perl matches
2688
2689 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2690 \Qabc\$xyz\E abc\$xyz abc\$xyz
2691 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2692
2693 For compatibility with Perl, \Q...\E sequences are recognized inside character
2694 classes as well as outside them.
2695
2696 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2697 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2698 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2699 signed/unsigned warnings.
2700
2701 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2702 option for pcretest, so I've replaced it by a simple function that does just
2703 that job.
2704
2705 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2706 "pcregrep -".
2707
2708 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2709 Java package. This provides some syntactic sugar for simple cases of what my
2710 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2711 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2712 item, you can use this simplified notation. Note that only makes sense with
2713 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2714 greediness, whatever the setting of the PCRE_UNGREEDY option.
2715
2716 13. A change of greediness default within a pattern was not taking effect at
2717 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2718 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2719 was abstracted outside.
2720
2721 14. PCRE now supports the \G assertion. It is true when the current matching
2722 position is at the start point of the match. This differs from \A when the
2723 starting offset is non-zero. Used with the /g option of pcretest (or similar
2724 code), it works in the same way as it does for Perl's /g option. If all
2725 alternatives of a regex begin with \G, the expression is anchored to the start
2726 match position, and the "anchored" flag is set in the compiled expression.
2727
2728 15. Some bugs concerning the handling of certain option changes within patterns
2729 have been fixed. These applied to options other than (?ims). For example,
2730 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2731 been the other way round. Some of this was related to change 7 above.
2732
2733 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2734 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2735 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2736 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2737
2738 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2739 mode. Unlike ".", it always matches newline, whatever the setting of
2740 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2741 assertions. Perl allows it, but it doesn't (in general) work because it can't
2742 calculate the length of the lookbehind. At least, that's the case for Perl
2743 5.8.0 - I've been told they are going to document that it doesn't work in
2744 future.
2745
2746 18. Added an error diagnosis for escapes that PCRE does not support: these are
2747 \L, \l, \N, \P, \p, \U, \u, and \X.
2748
2749 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2750 reading past the end of the pattern in cases such as /[abcd/.
2751
2752 20. PCRE was getting more memory than necessary for patterns with classes that
2753 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2754
2755 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2756 compiling PCRE for use with Virtual Pascal.
2757
2758 22. Small fix to the Makefile to make it work properly if the build is done
2759 outside the source tree.
2760
2761 23. Added a new extension: a condition to go with recursion. If a conditional
2762 subpattern starts with (?(R) the "true" branch is used if recursion has
2763 happened, whereas the "false" branch is used only at the top level.
2764
2765 24. When there was a very long string of literal characters (over 255 bytes
2766 without UTF support, over 250 bytes with UTF support), the computation of how
2767 much memory was required could be incorrect, leading to segfaults or other
2768 strange effects.
2769
2770 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2771 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2772 there was a subsequent back reference to those brackets. This meant that, for
2773 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2774 possible to check for precisely this case. All we can do is abandon the
2775 optimization if .* occurs inside capturing brackets when there are any back
2776 references whatsoever. (See below for a better fix that came later.)
2777
2778 26. The handling of the optimization for finding the first character of a
2779 non-anchored pattern, and for finding a character that is required later in the
2780 match were failing in some cases. This didn't break the matching; it just
2781 failed to optimize when it could. The way this is done has been re-implemented.
2782
2783 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2784
2785 28. Added a new feature that provides some of the functionality that Perl
2786 provides with (?{...}). The facility is termed a "callout". The way it is done
2787 in PCRE is for the caller to provide an optional function, by setting
2788 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2789 global variable. By default it is unset, which disables all calling out. To get
2790 the function called, the regex must include (?C) at appropriate points. This
2791 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2792 This provides a means of identifying different callout points. When PCRE
2793 reaches such a point in the regex, if pcre_callout has been set, the external
2794 function is called. It is provided with data in a structure called
2795 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2796 matching continues; if it returns a non-zero value, the match at the current
2797 point fails. However, backtracking will occur if possible. [This was changed
2798 later and other features added - see item 49 below.]
2799
2800 29. pcretest is upgraded to test the callout functionality. It provides a
2801 callout function that displays information. By default, it shows the start of
2802 the match and the current position in the text. There are some new data escapes
2803 to vary what happens:
2804
2805 \C+ in addition, show current contents of captured substrings
2806 \C- do not supply a callout function
2807 \C!n return 1 when callout number n is reached
2808 \C!n!m return 1 when callout number n is reached for the mth time
2809
2810 30. If pcregrep was called with the -l option and just a single file name, it
2811 output "<stdin>" if a match was found, instead of the file name.
2812
2813 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2814 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2815 pcre_exec(). This saves a malloc/free per call. The default value of
2816 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2817 when configuring.
2818
2819 32. The default maximum size of a compiled pattern is 64K. There have been a
2820 few cases of people hitting this limit. The code now uses macros to handle the
2821 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2822 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2823 configuring. Tests 2 and 5 work only with 2-byte links because they output
2824 debugging information about compiled patterns.
2825
2826 33. Internal code re-arrangements:
2827
2828 (a) Moved the debugging function for printing out a compiled regex into
2829 its own source file (printint.c) and used #include to pull it into
2830 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2831 separate copies.
2832
2833 (b) Defined the list of op-code names for debugging as a macro in
2834 internal.h so that it is next to the definition of the opcodes.
2835
2836 (c) Defined a table of op-code lengths for simpler skipping along compiled
2837 code. This is again a macro in internal.h so that it is next to the
2838 definition of the opcodes.
2839
2840 34. Added support for recursive calls to individual subpatterns, along the
2841 lines of Robin Houston's patch (but implemented somewhat differently).
2842
2843 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2844 allow it to read and process whole directories in Win32. This code was
2845 contributed by Lionel Fourquaux; it has not been tested by me.
2846
2847 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2848 used to name a group. Names consist of alphanumerics and underscores, and must
2849 be unique. Back references use the syntax (?P=name) and recursive calls use
2850 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2851 numbers. The function pcre_fullinfo() can be used after compilation to extract
2852 a name/number map. There are three relevant calls:
2853
2854 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2855 PCRE_INFO_NAMECOUNT yields the number of entries
2856 PCRE_INFO_NAMETABLE yields a pointer to the map.
2857
2858 The map is a vector of fixed-size entries. The size of each entry depends on
2859 the length of the longest name used. The first two bytes of each entry are the
2860 group number, most significant byte first. There follows the corresponding
2861 name, zero terminated. The names are in alphabetical order.
2862
2863 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2864 case instead of 255. Making it the same both with and without UTF-8 support
2865 means that the same test output works with both.
2866
2867 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2868 calling malloc() with a zero argument.
2869
2870 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2871 optimization. I've improved things by keeping a bitmap of backreferences with
2872 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2873 fact referenced, the optimization can be applied. It is unlikely that a
2874 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2875 the match to follow \n) will appear inside brackets with a number greater than
2876 31, but if it does, any back reference > 31 suppresses the optimization.
2877
2878 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2879 of disabling numbered capturing parentheses. Any opening parenthesis that is
2880 not followed by ? behaves as if it were followed by ?: but named parentheses
2881 can still be used for capturing (and they will acquire numbers in the usual
2882 way).
2883
2884 41. Redesigned the return codes from the match() function into yes/no/error so
2885 that errors can be passed back from deep inside the nested calls. A malloc
2886 failure while inside a recursive subpattern call now causes the
2887 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2888
2889 42. It is now possible to set a limit on the number of times the match()
2890 function is called in a call to pcre_exec(). This facility makes it possible to
2891 limit the amount of recursion and backtracking, though not in a directly
2892 obvious way, because the match() function is used in a number of different
2893 circumstances. The count starts from zero for each position in the subject
2894 string (for non-anchored patterns). The default limit is, for compatibility, a
2895 large number, namely 10 000 000. You can change this in two ways:
2896
2897 (a) When configuring PCRE before making, you can use --with-match-limit=n
2898 to set a default value for the compiled library.
2899
2900 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2901 a different value is set. See 45 below.
2902
2903 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2904
2905 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2906 of things that can be changed at compile time. The first argument specifies
2907 what is wanted and the second points to where the information is to be placed.
2908 The current list of available information is:
2909
2910 PCRE_CONFIG_UTF8
2911
2912 The output is an integer that is set to one if UTF-8 support is available;
2913 otherwise it is set to zero.
2914
2915 PCRE_CONFIG_NEWLINE
2916
2917 The output is an integer that it set to the value of the code that is used for
2918 newline. It is either LF (10) or CR (13).
2919
2920 PCRE_CONFIG_LINK_SIZE
2921
2922 The output is an integer that contains the number of bytes used for internal
2923 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2924
2925 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2926
2927 The output is an integer that contains the threshold above which the POSIX
2928 interface uses malloc() for output vectors. See item 31 above.
2929
2930 PCRE_CONFIG_MATCH_LIMIT
2931
2932 The output is an unsigned integer that contains the default limit of the number
2933 of match() calls in a pcre_exec() execution. See 42 above.
2934
2935 44. pcretest has been upgraded by the addition of the -C option. This causes it
2936 to extract all the available output from the new pcre_config() function, and to
2937 output it. The program then exits immediately.
2938
2939 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2940 order to support additional features. One way would have been to define
2941 pcre_exec2() (for example) with extra arguments, but this would not have been
2942 extensible, and would also have required all calls to the original function to
2943 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2944 is used for passing in "extra" data from pcre_study().
2945
2946 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2947 contains the following fields:
2948
2949 flags a bitmap indicating which of the following fields are set
2950 study_data opaque data from pcre_study()
2951 match_limit a way of specifying a limit on match() calls for a specific
2952 call to pcre_exec()
2953 callout_data data for callouts (see 49 below)
2954
2955 The flag bits are also defined in pcre.h, and are
2956
2957 PCRE_EXTRA_STUDY_DATA
2958 PCRE_EXTRA_MATCH_LIMIT
2959 PCRE_EXTRA_CALLOUT_DATA
2960
2961 The pcre_study() function now returns one of these new pcre_extra blocks, with
2962 the actual study data pointed to by the study_data field, and the
2963 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2964 before. That is, this change is entirely upwards-compatible and requires no
2965 change to existing code.
2966
2967 If you want to pass in additional data to pcre_exec(), you can either place it
2968 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2969 block.
2970
2971 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2972 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2973 times with different match limits, until it finds the minimum value needed for
2974 pcre_exec() to complete. The value is then output. This can be instructive; for
2975 most simple matches the number is quite small, but for pathological cases it
2976 gets very large very quickly.
2977
2978 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2979 returns the size of the data block pointed to by the study_data field in a
2980 pcre_extra block, that is, the value that was passed as the argument to
2981 pcre_malloc() when PCRE was getting memory in which to place the information
2982 created by pcre_study(). The fourth argument should point to a size_t variable.
2983 pcretest has been extended so that this information is shown after a successful
2984 pcre_study() call when information about the compiled regex is being displayed.
2985
2986 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2987 because what follows is always an absolute path. (Later: it turns out that this
2988 is more than cosmetic for MinGW, because it doesn't like empty path
2989 components.)
2990
2991 49. Some changes have been made to the callout feature (see 28 above):
2992
2993 (i) A callout function now has three choices for what it returns:
2994
2995 0 => success, carry on matching
2996 > 0 => failure at this point, but backtrack if possible
2997 < 0 => serious error, return this value from pcre_exec()
2998
2999 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3000 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3001 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3002 use by callout functions. It will never be used by PCRE itself.
3003
3004 (ii) The pcre_extra structure (see 45 above) has a void * field called
3005 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3006 pcre_callout_block structure has a field of the same name. The contents of
3007 the field passed in the pcre_extra structure are passed to the callout
3008 function in the corresponding field in the callout block. This makes it
3009 easier to use the same callout-containing regex from multiple threads. For
3010 testing, the pcretest program has a new data escape
3011
3012 \C*n pass the number n (may be negative) as callout_data
3013
3014 If the callout function in pcretest receives a non-zero value as
3015 callout_data, it returns that value.
3016
3017 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3018 there were some redundant $(CFLAGS) in commands that are now specified as
3019 $(LINK), which already includes $(CFLAGS).
3020
3021 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3022 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3023 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3024 one-byte characters throughout. Note that case-insensitive matching applies
3025 only to characters whose values are less than 256. PCRE doesn't support the
3026 notion of cases for higher-valued characters.
3027
3028 (i) A character class whose characters are all within 0-255 is handled as
3029 a bit map, and the map is inverted for negative classes. Previously, a
3030 character > 255 always failed to match such a class; however it should
3031 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3032
3033 (ii) A negated character class with a single character < 255 is coded as
3034 "not this character" (OP_NOT). This wasn't working properly when the test
3035 character was multibyte, either singly or repeated.
3036
3037 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3038 mode, for example: \x{100}{2,3}.
3039
3040 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3041 singly or repeated) now correctly test multibyte characters. However,
3042 PCRE doesn't recognize any characters with values greater than 255 as
3043 digits, spaces, or word characters. Such characters always match \D, \S,
3044 and \W, and never match \d, \s, or \w.
3045
3046 (v) Classes may now contain characters and character ranges with values
3047 greater than 255. For example: [ab\x{100}-\x{400}].
3048
3049 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3050 PCRE in UTF-8 mode.
3051
3052 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3053 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3054 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3055 value.)
3056
3057 53. The single man page has become too large. I have therefore split it up into
3058 a number of separate man pages. These also give rise to individual HTML pages;
3059 these are now put in a separate directory, and there is an index.html page that
3060 lists them all. Some hyperlinking between the pages has been installed.
3061
3062 54. Added convenience functions for handling named capturing parentheses.
3063
3064 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3065 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3066 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3067 are faulted.
3068
3069 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3070 calling configure. These values are used when compiling the dftables.c program
3071 which is run to generate the source of the default character tables. They
3072 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3073 you will need to set these values.
3074
3075 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3076
3077
3078 Version 3.9 02-Jan-02
3079 ---------------------
3080
3081 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3082
3083 2. If --disable-static was given, the building process failed when trying to
3084 build pcretest and pcregrep. (For some reason it was using libtool to compile
3085 them, which is not right, as they aren't part of the library.)
3086
3087
3088 Version 3.8 18-Dec-01
3089 ---------------------
3090
3091 1. The experimental UTF-8 code was completely screwed up. It was packing the
3092 bytes in the wrong order. How dumb can you get?
3093
3094
3095 Version 3.7 29-Oct-01
3096 ---------------------
3097
3098 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3099 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3100 this didn't happen under Solaris 8, where I normally test things.
3101
3102 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3103 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3104 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3105 this fix an hour or so after the initial 3.7 release.)
3106
3107
3108 Version 3.6 23-Oct-01
3109 ---------------------
3110
3111 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3112 offsets passed as NULL with zero offset count.
3113
3114 2. The config.guess and config.sub files had not been updated when I moved to
3115 the latest autoconf.
3116
3117
3118 Version 3.5 15-Aug-01
3119 ---------------------
3120
3121 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3122 had been forgotten.
3123
3124 2. By using declared but undefined structures, we can avoid using "void"
3125 definitions in pcre.h while keeping the internal definitions of the structures
3126 private.
3127
3128 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3129 user point of view, this means that both static and shared libraries are built
3130 by default, but this can be individually controlled. More of the work of
3131 handling this static/shared cases is now inside libtool instead of PCRE's make
3132 file.
3133
3134 4. The pcretest utility is now installed along with pcregrep because it is
3135 useful for users (to test regexs) and by doing this, it automatically gets
3136 relinked by libtool. The documentation has been turned into a man page, so
3137 there are now .1, .txt, and .html versions in /doc.
3138
3139 5. Upgrades to pcregrep:
3140 (i) Added long-form option names like gnu grep.
3141 (ii) Added --help to list all options with an explanatory phrase.
3142 (iii) Added -r, --recursive to recurse into sub-directories.
3143 (iv) Added -f, --file to read patterns from a file.
3144
3145 6. pcre_exec() was referring to its "code" argument before testing that
3146 argument for NULL (and giving an error if it was NULL).
3147
3148 7. Upgraded Makefile.in to allow for compiling in a different directory from
3149 the source directory.
3150
3151 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3152 options bits, the pointer it was passed was to an int instead of to an unsigned
3153 long int. This mattered only on 64-bit systems.
3154
3155 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3156 generated) instead of pcre.in, which it its source. Also made the same change
3157 in several of the .c files.
3158
3159 10. A new release of gcc defines printf() as a macro, which broke pcretest
3160 because it had an ifdef in the middle of a string argument for printf(). Fixed
3161 by using separate calls to printf().
3162
3163 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3164 script, to force use of CR or LF instead of \n in the source. On non-Unix
3165 systems, the value can be set in config.h.
3166
3167 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3168 absolute limit. Changed the text of the error message to make this clear, and
3169 likewise updated the man page.
3170
3171 13. The limit of 99 on the number of capturing subpatterns has been removed.
3172 The new limit is 65535, which I hope will not be a "real" limit.
3173
3174
3175 Version 3.4 22-Aug-00
3176 ---------------------
3177
3178 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3179
3180 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3181
3182
3183 Version 3.3 01-Aug-00
3184 ---------------------
3185
3186 1. If an octal character was given, but the value was greater than \377, it
3187 was not getting masked to the least significant bits, as documented. This could
3188 lead to crashes in some systems.
3189
3190 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3191 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3192
3193 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3194 These just pass their arguments on to (pcre_free)(), but they are provided
3195 because some uses of PCRE bind it to non-C systems that can call its functions,
3196 but cannot call free() or pcre_free() directly.
3197
3198 4. Add "make test" as a synonym for "make check". Corrected some comments in
3199 the Makefile.
3200
3201 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3202 Makefile.
3203
3204 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3205 command called pgrep for grepping around the active processes.
3206
3207 7. Added the beginnings of support for UTF-8 character strings.
3208
3209 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3210 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3211 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3212 out for the ar command.)
3213
3214
3215 Version 3.2 12-May-00
3216 ---------------------
3217
3218 This is purely a bug fixing release.
3219
3220 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3221 of ZA. This was just one example of several cases that could provoke this bug,
3222 which was introduced by change 9 of version 2.00. The code for breaking
3223 infinite loops after an iteration that matches an empty string was't working
3224 correctly.
3225
3226 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3227 when matched against abbab (for example). After matching an empty string, it
3228 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3229 caused it to match further down the string than it should.
3230
3231 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3232 was there because it doesn't seem to be needed, and it causes trouble on some
3233 systems, as it is not a Standard C header. It has been removed.
3234
3235 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3236 were reported on the Macintosh. The changes were from
3237
3238 while ((c = *(++ptr)) != 0 && c != '\n');
3239 to
3240 while ((c = *(++ptr)) != 0 && c != '\n') ;
3241
3242 Totally extraordinary, but if that's what it takes...
3243
3244 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3245 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3246 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3247 assumes the way PCRE uses memmove() (always moving upwards).
3248
3249 6. PCRE is being used in one environment where strchr() is not available. There
3250 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3251 faster code anyway.
3252
3253
3254 Version 3.1 09-Feb-00
3255 ---------------------
3256
3257 The only change in this release is the fixing of some bugs in Makefile.in for
3258 the "install" target:
3259
3260 (1) It was failing to install pcreposix.h.
3261
3262 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3263
3264
3265 Version 3.0 01-Feb-00
3266 ---------------------
3267
3268 1. Add support for the /+ modifier to perltest (to output $` like it does in
3269 pcretest).
3270
3271 2. Add support for the /g modifier to perltest.
3272
3273 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3274 matches null strings.
3275
3276 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3277 pattern. Perl treats empty patterns specially - it reuses the most recent
3278 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3279 effect.
3280
3281 5. The POSIX interface was broken in that it was just handing over the POSIX
3282 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3283 required a bigger vector, with some working space on the end. This means that
3284 the POSIX wrapper now has to get and free some memory, and copy the results.
3285
3286 6. Added some simple autoconf support, placing the test data and the
3287 documentation in separate directories, re-organizing some of the
3288 information files, and making it build pcre-config (a GNU standard). Also added
3289 libtool support for building PCRE as a shared library, which is now the
3290 default.
3291
3292 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3293 09 are not valid octal constants. Single digits will be used for minor values
3294 less than 10.
3295
3296 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3297 existing programs that set these in the POSIX interface can use PCRE without
3298 modification.
3299
3300 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3301 return all that pcre_info() returns, plus additional data. The pcre_info()
3302 function is retained for compatibility, but is considered to be obsolete.
3303
3304 10. Added experimental recursion feature (?R) to handle one common case that
3305 Perl 5.6 will be able to do with (?p{...}).
3306
3307 11. Added support for POSIX character classes like [:alpha:], which Perl is
3308 adopting.
3309
3310
3311 Version 2.08 31-Aug-99
3312 ----------------------
3313
3314 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3315 trying to match at the startoffset position, but instead was moving forward to
3316 the next newline as if a previous match had failed.
3317
3318 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3319 and could get into a loop if a null string was matched other than at the start
3320 of the subject.
3321
3322 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3323 be distinguished at compile time, and for completeness also added PCRE_DATE.
3324
3325 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3326 in GnuWin32 environments.
3327
3328
3329 Version 2.07 29-Jul-99
3330 ----------------------
3331
3332 1. The documentation is now supplied in plain text form and HTML as well as in
3333 the form of man page sources.
3334
3335 2. C++ compilers don't like assigning (void *) values to other pointer types.
3336 In particular this affects malloc(). Although there is no problem in Standard
3337 C, I've put in casts to keep C++ compilers happy.
3338
3339 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3340 should be (const char *).
3341
3342 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3343 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3344 However, I haven't made this a standard facility. The documentation doesn't
3345 mention it, and the Makefile doesn't support it.
3346
3347 5. The Makefile now contains an "install" target, with editable destinations at
3348 the top of the file. The pcretest program is not installed.
3349
3350 6. pgrep -V now gives the PCRE version number and date.
3351
3352 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3353 causing the entire string to be ignored, instead of just the last character.
3354
3355 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3356 non-matching string, it can take a very, very long time, even for strings of
3357 quite modest length, because of the nested recursion. PCRE now does better in
3358 some of these cases. It does this by remembering the last required literal
3359 character in the pattern, and pre-searching the subject to ensure it is present
3360 before running the real match. In other words, it applies a heuristic to detect
3361 some types of certain failure quickly, and in the above example, if presented
3362 with a string that has no trailing " it gives "no match" very quickly.
3363
3364 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3365 other alternatives are tried instead.
3366
3367
3368 Version 2.06 09-Jun-99
3369 ----------------------
3370
3371 1. Change pcretest's output for amount of store used to show just the code
3372 space, because the remainder (the data block) varies in size between 32-bit and
3373 64-bit systems.
3374
3375 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3376 start matching at. This allows lookbehinds to work when searching for multiple
3377 occurrences in a string.
3378
3379 3. Added additional options to pcretest for testing multiple occurrences:
3380
3381 /+ outputs the rest of the string that follows a match
3382 /g loops for multiple occurrences, using the new startoffset argument
3383 /G loops for multiple occurrences by passing an incremented pointer
3384
3385 4. PCRE wasn't doing the "first character" optimization for patterns starting
3386 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3387 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3388 the letter 'x'. On long subject strings, this gives a significant speed-up.
3389
3390
3391 Version 2.05 21-Apr-99
3392 ----------------------
3393
3394 1. Changed the type of magic_number from int to long int so that it works
3395 properly on 16-bit systems.
3396
3397 2. Fixed a bug which caused patterns starting with .* not to work correctly
3398 when the subject string contained newline characters. PCRE was assuming
3399 anchoring for such patterns in all cases, which is not correct because .* will
3400 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3401 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3402 must be retried after every newline in the subject.
3403
3404
3405 Version 2.04 18-Feb-99
3406 ----------------------
3407
3408 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3409 computation of the store needed to hold the pattern was incorrect (too large).
3410 If such patterns were nested a few deep, this could multiply and become a real
3411 problem.
3412
3413 2. Added /M option to pcretest to show the memory requirement of a specific
3414 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3415
3416 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3417 compiled in such a way that the backtracking after subsequent failure was
3418 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3419 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3420
3421
3422 Version 2.03 02-Feb-99
3423 ----------------------
3424
3425 1. Fixed typo and small mistake in man page.
3426
3427 2. Added 4th condition (GPL supersedes if conflict) and created separate
3428 LICENCE file containing the conditions.
3429
3430 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3431 Perl, that is the internal \ allows the delimiter to be included in the
3432 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3433 the final delimiter, add \ to the end of the pattern (to test the error).
3434
3435 4. Added the convenience functions for extracting substrings after a successful
3436 match. Updated pcretest to make it able to test these functions.
3437
3438
3439 Version 2.02 14-Jan-99
3440 ----------------------
3441
3442 1. Initialized the working variables associated with each extraction so that
3443 their saving and restoring doesn't refer to uninitialized store.
3444
3445 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3446 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3447 fix the problem.
3448
3449 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3450 calls, and wasn't printing the correct value for compiling calls. Increased the
3451 default value of LOOPREPEAT, and the number of significant figures in the
3452 times.
3453
3454 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3455
3456 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3457 a building problem on Windows NT with a FAT file system.
3458
3459
3460 Version 2.01 21-Oct-98
3461 ----------------------
3462
3463 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3464 to character tables built by pcre_maketables() in the current locale. If NULL
3465 is passed, the default tables are used.
3466
3467
3468 Version 2.00 24-Sep-98
3469 ----------------------
3470
3471 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3472 it any more.
3473
3474 2. Allow quantification of (?>) groups, and make it work correctly.
3475
3476 3. The first character computation wasn't working for (?>) groups.
3477
3478 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3479 end of the subject) and add 5.005's \z, which really does match only at the
3480 very end of the subject.
3481
3482 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3483
3484 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3485 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3486 localized options. All options to pcre_study() were also removed.
3487
3488 7. Add other new features from 5.005:
3489
3490 $(?<= positive lookbehind
3491 $(?<! negative lookbehind
3492 (?imsx-imsx) added the unsetting capability
3493 such a setting is global if at outer level; local otherwise
3494 (?imsx-imsx:) non-capturing groups with option setting
3495 (?(cond)re|re) conditional pattern matching
3496
3497 A backreference to itself in a repeated group matches the previous
3498 captured string.
3499
3500 8. General tidying up of studying (both automatic and via "study")
3501 consequential on the addition of new assertions.
3502
3503 9. As in 5.005, unlimited repeated groups that could match an empty substring
3504 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3505 runtime if any iteration does actually match an empty substring.
3506
3507 10. Include the RunTest script in the distribution.
3508
3509 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3510 discrepancies, some of which were old and were also with respect to 5.004. They
3511 have now been fixed.
3512
3513
3514 Version 1.09 28-Apr-98
3515 ----------------------
3516
3517 1. A negated single character class followed by a quantifier with a minimum
3518 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3519 program crashes, or just wrong answers. This did not apply to negated classes
3520 containing more than one character, or to minima other than one.
3521
3522
3523 Version 1.08 27-Mar-98
3524 ----------------------
3525
3526 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3527
3528 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3529 latter must appear before anything that relies on it in the pattern.
3530
3531
3532 Version 1.07 16-Feb-98
3533 ----------------------
3534
3535 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3536 repeat of a potentially empty string).
3537
3538
3539 Version 1.06 23-Jan-98
3540 ----------------------
3541
3542 1. Added Markus Oberhumer's little patches for C++.
3543
3544 2. Literal strings longer than 255 characters were broken.
3545
3546
3547 Version 1.05 23-Dec-97
3548 ----------------------
3549
3550 1. Negated character classes containing more than one character were failing if
3551 PCRE_CASELESS was set at run time.
3552
3553
3554 Version 1.04 19-Dec-97
3555 ----------------------
3556
3557 1. Corrected the man page, where some "const" qualifiers had been omitted.
3558
3559 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3560 input syntax.
3561
3562 3. Fixed memory leak which occurred when a regex with back references was
3563 matched with an offsets vector that wasn't big enough. The temporary memory
3564 that is used in this case wasn't being freed if the match failed.
3565
3566 4. Tidied pcretest to ensure it frees memory that it gets.
3567
3568 5. Temporary memory was being obtained in the case where the passed offsets
3569 vector was exactly big enough.
3570
3571 6. Corrected definition of offsetof() from change 5 below.
3572
3573 7. I had screwed up change 6 below and broken the rules for the use of
3574 setjmp(). Now fixed.
3575
3576
3577 Version 1.03 18-Dec-97
3578 ----------------------
3579
3580 1. A erroneous regex with a missing opening parenthesis was correctly
3581 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3582 on some systems.
3583
3584 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3585 it was reported that one broken compiler failed on the former because "code" is
3586 also an independent variable.
3587
3588 3. The erroneous regex a[]b caused an array overrun reference.
3589
3590 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3591 fail on data ending with that character. (It was going on too far, and checking
3592 the next character, typically a binary zero.) This was specific to the
3593 optimized code for single-character negative classes.
3594
3595 5. Added a contributed patch from the TIN world which does the following:
3596
3597 + Add an undef for memmove, in case the the system defines a macro for it.
3598
3599 + Add a definition of offsetof(), in case there isn't one. (I don't know
3600 the reason behind this - offsetof() is part of the ANSI standard - but
3601 it does no harm).
3602
3603 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3604 most of the places where whitespace preceded '#'. I have given up and
3605 allowed the remaining 2 cases to be at the margin.
3606
3607 + Rename some variables in pcre to eliminate shadowing. This seems very
3608 pedantic, but does no harm, of course.
3609
3610 6. Moved the call to setjmp() into its own function, to get rid of warnings
3611 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3612
3613 7. Constructs such as \d{8,} were compiling into the equivalent of
3614 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3615 outcome, but in this particular case used more store than had been allocated,
3616 which caused the bug to be discovered because it threw up an internal error.
3617
3618 8. The debugging code in both pcre and pcretest for outputting the compiled
3619 form of a regex was going wrong in the case of back references followed by
3620 curly-bracketed repeats.
3621
3622
3623 Version 1.02 12-Dec-97
3624 ----------------------
3625
3626 1. Typos in pcre.3 and comments in the source fixed.
3627
3628 2. Applied a contributed patch to get rid of places where it used to remove
3629 'const' from variables, and fixed some signed/unsigned and uninitialized
3630 variable warnings.
3631
3632 3. Added the "runtest" target to Makefile.
3633
3634 4. Set default compiler flag to -O2 rather than just -O.
3635
3636
3637 Version 1.01 19-Nov-97
3638 ----------------------
3639
3640 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3641 like /([ab]*)*/, that is, for classes with more than one character in them.
3642
3643 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3644 as /((?>a*))*/ (a PCRE_EXTRA facility).
3645
3646
3647 Version 1.00 18-Nov-97
3648 ----------------------
3649
3650 1. Added compile-time macros to support systems such as SunOS4 which don't have
3651 memmove() or strerror() but have other things that can be used instead.
3652
3653 2. Arranged that "make clean" removes the executables.
3654
3655
3656 Version 0.99 27-Oct-97
3657 ----------------------
3658
3659 1. Fixed bug in code for optimizing classes with only one character. It was
3660 initializing a 32-byte map regardless, which could cause it to run off the end
3661 of the memory it had got.
3662
3663 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3664
3665
3666 Version 0.98 22-Oct-97
3667 ----------------------
3668
3669 1. Fixed bug in code for handling temporary memory usage when there are more
3670 back references than supplied space in the ovector. This could cause segfaults.
3671
3672
3673 Version 0.97 21-Oct-97
3674 ----------------------
3675
3676 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3677
3678 2. Optimized negated single characters not to use a bit map.
3679
3680 3. Brought error texts together as macro definitions; clarified some of them;
3681 fixed one that was wrong - it said "range out of order" when it meant "invalid
3682 escape sequence".
3683
3684 4. Changed some char * arguments to const char *.
3685
3686 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3687
3688 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3689 pcretest.
3690
3691
3692 Version 0.96 16-Oct-97
3693 ----------------------
3694
3695 1. Added a simple "pgrep" utility to the distribution.
3696
3697 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3698 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3699 where "ddd" means "one or more decimal digits".
3700
3701 3. Fixed serious bug. If a pattern had a back reference, but the call to
3702 pcre_exec() didn't supply a large enough ovector to record the related
3703 identifying subpattern, the match always failed. PCRE now remembers the number
3704 of the largest back reference, and gets some temporary memory in which to save
3705 the offsets during matching if necessary, in order to ensure that
3706 backreferences always work.
3707
3708 4. Increased the compatibility with Perl in a number of ways:
3709
3710 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3711 to request this handling. The option can be set at compile or exec time.
3712
3713 (b) $ matches before a terminating newline by default; an option
3714 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3715 mode). The option can be set at compile or exec time.
3716
3717 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3718 the same as Perl's. If the decimal number it represents is less than 10
3719 or there aren't that many previous left capturing parentheses, an octal
3720 escape is read. Inside a character class, it's always an octal escape,
3721 even if it is a single digit.
3722
3723 (d) An escaped but undefined alphabetic character is taken as a literal,
3724 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3725 escapes.
3726
3727 (e) {0} is now permitted. (The previous item is removed from the compiled
3728 pattern).
3729
3730 5. Changed all the names of code files so that the basic parts are no longer
3731 than 10 characters, and abolished the teeny "globals.c" file.
3732
3733 6. Changed the handling of character classes; they are now done with a 32-byte
3734 bit map always.
3735
3736 7. Added the -d and /D options to pcretest to make it possible to look at the
3737 internals of compilation without having to recompile pcre.
3738
3739
3740 Version 0.95 23-Sep-97
3741 ----------------------
3742
3743 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3744 \x20 at the start of a run of normal characters. These were being treated as
3745 real characters, instead of the source characters being re-checked.
3746
3747
3748 Version 0.94 18-Sep-97
3749 ----------------------
3750
3751 1. The functions are now thread-safe, with the caveat that the global variables
3752 containing pointers to malloc() and free() or alternative functions are the
3753 same for all threads.
3754
3755 2. Get pcre_study() to generate a bitmap of initial characters for non-
3756 anchored patterns when this is possible, and use it if passed to pcre_exec().
3757
3758
3759 Version 0.93 15-Sep-97
3760 ----------------------
3761
3762 1. /(b)|(:+)/ was computing an incorrect first character.
3763
3764 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3765 but not actually doing anything yet.
3766
3767 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3768 as Perl does (e.g. [-az] or [az-]).
3769
3770 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3771 all possible positions.
3772
3773 5. Split up into different modules to avoid including unneeded functions in a
3774 compiled binary. However, compile and exec are still in one module. The "study"
3775 function is split off.
3776
3777 6. The character tables are now in a separate module whose source is generated
3778 by an auxiliary program - but can then be edited by hand if required. There are
3779 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3780 toupper() in the code.
3781
3782 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3783 make them global. Abolish the function for setting them, as the caller can now
3784 set them directly.
3785
3786
3787 Version 0.92 11-Sep-97
3788 ----------------------
3789
3790 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3791 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3792
3793 2. Caseless matching was not working in character classes if the characters in
3794 the pattern were in upper case.
3795
3796 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3797
3798 4. Make PCRE_ANCHORED public and accept as a compile option.
3799
3800 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3801 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3802 pass them.
3803
3804 6. Give an error if bad option bits passed at compile or run time.
3805
3806 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3807 pcretest to cause it to pass that flag.
3808
3809 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3810 options, and the first character, if set.
3811
3812 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3813
3814
3815 Version 0.91 10-Sep-97
3816 ----------------------
3817
3818 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3819 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3820
3821 2. PCRE was looping on encountering an indefinitely repeated back reference to
3822 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3823 Perl does - treats the match as successful.
3824
3825 ****

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