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Revision 492 - (hide annotations) (download)
Tue Mar 2 11:26:55 2010 UTC (5 years, 1 month ago) by ph10
File size: 181751 byte(s)
Added --libs-cpp to pcre-config, but only when C++ support is configured.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 491 Version 8.02 01-Mar-2010
5     ------------------------
7     1. The Unicode data tables have been updated to Unicode 5.2.0.
9 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
10     configured.
11 ph10 491
12 ph10 492
13 ph10 489 Version 8.01 19-Jan-2010
14     ------------------------
15 ph10 471
16     1. If a pattern contained a conditional subpattern with only one branch (in
17 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
18 ph10 473 computed the wrong minimum data length (which is of course zero for such
19 ph10 489 subpatterns). This could cause incorrect "no match" results.
20 ph10 473
21     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
22 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
23     "internal error: code overflow at offset...". This happened only when
24 ph10 473 the reset was to the original external option setting. (An optimization
25     abstracts leading options settings into an external setting, which was the
26 ph10 472 cause of this.)
27 ph10 471
28 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
29     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
30     assertion pattern did not match (meaning that the assertion was true), it
31     was incorrectly treated as false if the SKIP had been reached during the
32     matching. This also applied to assertions used as conditions.
33 ph10 471
34 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
35     assertion subpattern, including such a pattern used as a condition,
36     unpredictable results occurred, instead of the error return
38 ph10 478
39 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
40     situation when an empty string is matched. It now does the fancy magic
41 ph10 478 stuff that is necessary.
43     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
44 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
45 ph10 478
46 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
47     as part of something else:
48 ph10 478
49     (a) Change DEBUG to PCRE_DEBUG.
51     (b) In pcre_compile(), rename the member of the "branch_chain" structure
52     called "current" as "current_branch", to prevent a collision with the
53 ph10 475 Linux macro when compiled as a kernel module.
54 ph10 478
55     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
56     prevent a collision with the Linux macro when compiled as a kernel
57 ph10 475 module.
58 ph10 478
59 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
60     cast potentially large values to (double). This has been changed to that
61 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
62     instead, thus avoiding the use of floating point arithmetic. (There is no
63     other use of FP in PCRE.) If int64_t is not found, the fallback is to
64     double.
66     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
67 ph10 476 2005 (difference between two addresses compared to an unsigned value).
68 ph10 473
69 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
70     custom one, because of the following reported problem in Windows:
71 ph10 473
72 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
73 ph10 489 under Win32.
74 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
75 ph10 489 therefore missing the function definition.
76 ph10 478 - The compiler thus generates a "C" signature for the test function.
77     - The linker fails to find the "C" function.
78     - PCRE fails to configure if asked to do so against libbz2.
79 ph10 486
80 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
81     messages were output:
82 ph10 478
83 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
84     rerunning libtoolize, to keep the correct libtool macros in-tree.
85     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
86 ph10 486
87 ph10 479 I have done both of these things.
88 ph10 486
89 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
90 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
91     runaway infinite recursion. I updated the discussion in the pcrestack man
92     page.
94     13. Now that we have gone to the x.xx style of version numbers, the minor
95     version may start with zero. Using 08 or 09 is a bad idea because users
96     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
97     interpreted as invalid octal numbers. I've updated the previous comment in
98     configure.ac, and also added a check that gives an error if 08 or 09 are
99 ph10 481 used.
100 ph10 486
101 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
102 ph10 483 causing partial matching to fail when the end of the subject matched \W
103     in a UTF-8 pattern where \W was quantified with a minimum of 3.
104 ph10 486
105 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
106 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
107 ph10 483 their definitions. The declarations used "const uschar *" and the
108     definitions used USPTR. Even though USPTR is normally defined as "const
109     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
110     reported that: "This difference in casting confuses some C++ compilers, for
111     example, SunCC recognizes above declarations as different functions and
112 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
113 ph10 483 USPTR.
114 ph10 486
115     16. GNU libtool is named differently on some systems. The autogen.sh script now
116 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
117     (FreeBSD).
118 ph10 478
119 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
120     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
121     comment: "Figure out how to create a longlong from a string: strtoll and
122     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
123     instance, but it only takes 2 args instead of 3!"
124 ph10 479
125 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
126     specification, with a corresponding code fix. A pattern such as
127     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
128     refers, was giving matches when it shouldn't. For example, xa=xaaa would
129     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
130     same bug. Such groups have to be quantified to be useful, or contained
131     inside another quantified group. (If there's no repetition, the reference
132     can never match.) The problem arises because, having left the group and
133     moved on to the rest of the pattern, a later failure that backtracks into
134     the group uses the captured value from the final iteration of the group
135     rather than the correct earlier one. I have fixed this in PCRE by forcing
136     any group that contains a reference to itself to be an atomic group; that
137     is, there cannot be any backtracking into it once it has completed. This is
138     similar to recursive and subroutine calls.
139 ph10 486
140 ph10 488
141 ph10 469 Version 8.00 19-Oct-09
142 ph10 418 ----------------------
144     1. The table for translating pcre_compile() error codes into POSIX error codes
145 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
146     being within the table. This could lead to an OK return being given in
147 ph10 418 error.
148 ph10 461
149     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
150     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
151     in a Windows environment.
153 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
154     zero, as does GNU grep. However, pcregrep was also printing all files when
155     --files-with-matches was added. Now, when both options are given, it prints
156     counts only for those files that have at least one match. (GNU grep just
157 ph10 461 prints the file name in this circumstance, but including the count seems
158     more useful - otherwise, why use --count?) Also ensured that the
159 ph10 420 combination -clh just lists non-zero counts, with no names.
160 ph10 461
161     4. The long form of the pcregrep -F option was incorrectly implemented as
162     --fixed_strings instead of --fixed-strings. This is an incompatible change,
163     but it seems right to fix it, and I didn't think it was worth preserving
164     the old behaviour.
166     5. The command line items --regex=pattern and --regexp=pattern were not
167 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
168 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
169 ph10 422 which are compatible with GNU grep; these now work.
170 ph10 461
171     6. No libpcreposix.pc file was created for pkg-config; there was just
172 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
173 ph10 461
174 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
175 ph10 461 when UCP support is not needed, by modifying the Python script that
176 ph10 425 generates it from Unicode data files. This should not matter if the module
177     is correctly used as a library, but I received one complaint about 50K of
178     unwanted data. My guess is that the person linked everything into his
179     program rather than using a library. Anyway, it does no harm.
180 ph10 461
181 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
182 ph10 461 was a minimum greater than 1 for a wide character in a possessive
183 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
184     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
185     character. Chaos in the form of incorrect output or a compiling loop could
186     result.
187 ph10 461
188 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
189 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
190 ph10 426 partially matched by this function. In addition, if there are at least two
191 ph10 435 slots in the offset vector, the offset of the earliest inspected character
192     for the match and the offset of the end of the subject are set in them when
193 ph10 461 PCRE_ERROR_PARTIAL is returned.
195 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
196     synonymous with PCRE_PARTIAL, for backwards compatibility, and
197     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
198 ph10 462 and may be more useful for multi-segment matching.
199 ph10 461
200     11. Partial matching with pcre_exec() is now more intuitive. A partial match
201     used to be given if ever the end of the subject was reached; now it is
202     given only if matching could not proceed because another character was
203     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
204     string "Z", which now yields "no match" instead of "partial match". In the
205     case of pcre_dfa_exec(), "no match" is given if every matching path for the
206     final character ended with (*FAIL).
208 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
209 ph10 461 if the pattern had a "must contain" character that was already found in the
210 ph10 428 earlier partial match, unless partial matching was again requested. For
211     example, with the pattern /dog.(body)?/, the "must contain" character is
212     "g". If the first part-match was for the string "dog", restarting with
213 ph10 435 "sbody" failed. This bug has been fixed.
214 ph10 461
215     13. The string returned by pcre_dfa_exec() after a partial match has been
216     changed so that it starts at the first inspected character rather than the
217     first character of the match. This makes a difference only if the pattern
218     starts with a lookbehind assertion or \b or \B (\K is not supported by
219     pcre_dfa_exec()). It's an incompatible change, but it makes the two
220 ph10 435 matching functions compatible, and I think it's the right thing to do.
221 ph10 461
222 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
223 ph10 461 so that the demonstration program is easily available in environments where
224     PCRE has not been installed from source.
226 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
227 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
228     library.
229 ph10 461
230 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
231 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
232 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
233 ph10 433 these options useful.
234 ph10 461
235     17. If a caller to the POSIX matching function regexec() passes a non-zero
236 ph10 438 value for nmatch with a NULL value for pmatch, the value of
237 ph10 461 nmatch is forced to zero.
239 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
240 ph10 461 the diff command, as RunTest does. It now checks in the same way as
241 ph10 437 RunTest, and also checks for the -b option.
242 ph10 461
243 ph10 438 19. If an odd number of negated classes containing just a single character
244     interposed, within parentheses, between a forward reference to a named
245 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
246     an internal error, complaining that it could not find the referenced
247 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
248 ph10 461 [The bug was that it was starting one character too far in when skipping
249     over the character class, thus treating the ] as data rather than
250     terminating the class. This meant it could skip too much.]
252 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
253 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
254 ph10 442 to have an empty string match not at the start, even when the pattern is
255 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
257 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
258 ph10 461 than the maximum at the outer level, the higher number was returned, but
259     with unset values at the outer level. The correct (outer level) value is
260 ph10 446 now given.
261 ph10 461
262 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
263     PCRE did not set those parentheses (unlike Perl). I have now found a way to
264     make it do so. The string so far is captured, making this feature
265     compatible with Perl.
266 ph10 461
267     23. The tests have been re-organized, adding tests 11 and 12, to make it
268 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
269 ph10 461
270 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
271 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
272     does. Neither allows recursion.
274     25. I finally figured out how to implement a request to provide the minimum
275     length of subject string that was needed in order to match a given pattern.
276     (It was back references and recursion that I had previously got hung up
277     on.) This code has now been added to pcre_study(); it finds a lower bound
278 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
279     bound, but using it to avoid searching strings that are too short does give
280     some useful speed-ups. The value is available to calling programs via
281     pcre_fullinfo().
282 ph10 461
283 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
284     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
285     study optimizations had never been tested with that matching function.
286     Oops. What is worse, even when it was passed study data, there was a bug in
287     pcre_dfa_exec() that meant it never actually used it. Double oops. There
288     were also very few tests of studied patterns with pcre_dfa_exec().
289 ph10 461
290 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
291     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
292     on the other side of the coin, they are no longer allowed to have different
293     names, because these cannot be distinguished in PCRE, and this has caused
294     confusion. (This is a difference from Perl.)
295 ph10 461
296     28. When duplicate subpattern names are present (necessarily with different
297     numbers, as required by 27 above), and a test is made by name in a
298     conditional pattern, either for a subpattern having been matched, or for
299     recursion in such a pattern, all the associated numbered subpatterns are
300 ph10 459 tested, and the overall condition is true if the condition is true for any
301     one of them. This is the way Perl works, and is also more like the way
302     testing by number works.
303 ph10 418
304 ph10 461
305 ph10 412 Version 7.9 11-Apr-09
306 ph10 376 ---------------------
308 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
309 ph10 376 (pcretest), all targets were linked against these libraries. This included
310     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
311     libraries. This caused unwanted dependencies to be created. This problem
312 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
313 ph10 376 pcretest is linked with readline.
314 ph10 392
315 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
316     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
317     moved outside it again, because FALSE and TRUE are already defined in AIX,
318     but BOOL is not.
319 ph10 392
320     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
321 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
322 ph10 392
323 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
324     hyphens) following file names and line numbers when outputting matching
325 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
326 ph10 376 wording for the --colour (or --color) option.
327 ph10 392
328 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
329     was not coloured; this is different to GNU grep, so I have changed it to be
330     the same.
331 ph10 392
332 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
333 ph10 392 each matching line was coloured. Now it goes on to look for further matches
334     of any of the test patterns, which is the same behaviour as GNU grep.
336     7. A pattern that could match an empty string could cause pcregrep to loop; it
337     doesn't make sense to accept an empty string match in pcregrep, so I have
338 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
339     seems to be how GNU grep behaves.
340 ph10 392
341 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
342 ph10 392 start or after a newline", because the conditional assertion was not being
343     correctly handled. The rule now is that both the assertion and what follows
344     in the first alternative must satisfy the test.
346 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
347 ph10 399 condition was an assertion, PCRE could crash during matching, both with
348     pcre_exec() and pcre_dfa_exec().
349 ph10 392
350     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
351     used for matching.
353     11. Unicode property support in character classes was not working for
354 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
355 ph10 388
356 ph10 392 12. Added the -M command line option to pcretest.
358 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
359 ph10 389
360     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
361 ph10 390
362 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
363 ph10 390 wrapper.
364 ph10 392
365 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
366 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
367 ph10 391 string constants.
368 ph10 405
369 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
370     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
371 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
372     these, but not everybody uses configure.
374     19. A conditional group that had only one branch was not being correctly
375     recognized as an item that could match an empty string. This meant that an
376     enclosing group might also not be so recognized, causing infinite looping
377     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
378     with the subject "ab", where knowledge that the repeated group can match
379 ph10 396 nothing is needed in order to break the loop.
380 ph10 405
381 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
382 ph10 405 exec(), but without supplying a callout function, matching went wrong.
384     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
385     leak if the size of the offset vector was greater than 30. When the vector
386     is smaller, the saved offsets during recursion go onto a local stack
387     vector, but for larger vectors malloc() is used. It was failing to free
388     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
389 ph10 400 error, in fact).
390 ph10 405
391 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
392 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
393     problem, but was untidy.
394 ph10 376
395 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
396     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
397     included within another project.
398 ph10 411
399 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
400     slightly modified by me:
401 ph10 411
402     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
403     not building pcregrep.
405 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
406 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
408 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
409     duplicate group numbers, could behave incorrectly or give incorrect errors,
410     because when scanning forward to find the reference group, PCRE was not
411     taking into account the duplicate group numbers. A pattern such as
412     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
413 ph10 411
414     26. Changed a few more instances of "const unsigned char *" to USPTR, making
415     the feature of a custom pointer more persuasive (as requested by a user).
416 ph10 416
417 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
418 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
419     pre-defined.
420 ph10 392
421 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
423 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
424     in the configuration summary.
425 ph10 405
426 ph10 411
427 ph10 374 Version 7.8 05-Sep-08
428 ph10 349 ---------------------
430     1. Replaced UCP searching code with optimized version as implemented for Ad
431     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
432 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
433     to 5 times on some simple patterns that I tested. Permission was given to
434     distribute the MultiStage2.py script that generates the tables (it's not in
435     the tarball, but is in the Subversion repository).
436 ph10 349
437 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
438     scripts.
439 ph10 358
440 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
441     a group with a zero qualifier. The result of the study could be incorrect,
442 ph10 358 or the function might crash, depending on the pattern.
444     4. Caseless matching was not working for non-ASCII characters in back
445 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
446 ph10 358 It now works when Unicode Property Support is available.
448 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
449     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
450     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
451 ph10 358 truncation.
452 ph10 349
453 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
455 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
456     pointers, in case they are 64-bit values.
457 ph10 371
458     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
459     test 2 if it fails.
461 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
462 ph10 371 and a #define of that name to empty if it is not externally set. This is to
463     allow users of MSVC to set it if necessary.
465     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
466 ph10 359 the convenience functions in the pcre_get.c source file.
467 ph10 371
468 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
469     could cause overwriting and/or a crash. This command provoked a crash in
470 ph10 371 some environments:
472     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
474 ph10 360 This potential security problem was recorded as CVE-2008-2371.
475 ph10 371
476 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
477     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
478 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
479 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
480     pcretest so that it places the subject at the end of its malloc-ed buffer.
481 ph10 371
482 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
483 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
485 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
486 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
487     first line. This applied both to normal and DFA matching.
489 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
490 ph10 371 /^[^d]*?$/8 failed to match "abc".
491 ph10 351
492 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
494     17. Make it more clear in the documentation that values returned from
495 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
496 ph10 357
497 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
498 ph10 368
499 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
500     supplied by Stefan Weber. I made a further small update for 7.8 because
501 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
502     replaced by pcre_ucd.c.
503 ph10 371
504 ph10 373
505 ph10 347 Version 7.7 07-May-08
506 ph10 321 ---------------------
508     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
509 ph10 345 a string to a long long, pretend we don't even have a long long." This is
510 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
511 ph10 345
512 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
513     pre-7.6 versions, which defined a global no_arg variable instead of putting
514 ph10 332 it in the RE class. (See also #8 below.)
515 ph10 345
516     3. Remove a line of dead code, identified by coverity and reported by Nuno
517     Lopes.
519 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
520 ph10 321
521 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
522 ph10 345 of files, instead of just to the final components.
524 ph10 324 (2) If there was more than one level of directory, the subdirectories were
525     skipped unless they satisfied the include/exclude conditions. This is
526     inconsistent with GNU grep (and could even be seen as contrary to the
527     pcregrep specification - which I improved to make it absolutely clear).
528     The action now is always to scan all levels of directory, and just
529     apply the include/exclude patterns to regular files.
530 ph10 345
531 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
532 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
534 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
535 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
536 ph10 326 doesn't support NULs in patterns.
537 ph10 345
538     7. Added some missing "const"s to declarations of static tables in
539     pcre_compile.c and pcre_dfa_exec.c.
541 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
542 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
543 ph10 345 first patch. And a third patch - this was a messy problem.)
544 ph10 321
545 ph10 345 9. Applied Craig's patch to remove the use of push_back().
547 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
548     matching function regexec().
549 ph10 345
550     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
551     which, however, unlike Perl's \g{...}, are subroutine calls, not back
552 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
553     Oniguruma does).
554 ph10 345
555     12. Previously, a group with a zero repeat such as (...){0} was completely
556 ph10 335 omitted from the compiled regex. However, this means that if the group
557     was called as a subroutine from elsewhere in the pattern, things went wrong
558 ph10 345 (an internal error was given). Such groups are now left in the compiled
559     pattern, with a new opcode that causes them to be skipped at execution
560 ph10 335 time.
561 ph10 345
562 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
563     to the way PCRE behaves:
564 ph10 345
565 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
566 ph10 345
567     (b) A back reference to an unmatched subpattern matches an empty string
568 ph10 336 (Perl fails the current match path).
569 ph10 345
570 ph10 341 (c) A data ] in a character class must be notated as \] because if the
571 ph10 345 first data character in a class is ], it defines an empty class. (In
572 ph10 341 Perl it is not possible to have an empty class.) The empty class []
573     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
574     The negative empty class [^] matches any one character, independently
575     of the DOTALL setting.
576 ph10 345
577     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
578 ph10 340 non-existent subpattern following a character class starting with ']' and
579     containing () gave an internal compiling error instead of "reference to
580     non-existent subpattern". Fortunately, when the pattern did exist, the
581 ph10 345 compiled code was correct. (When scanning forwards to check for the
582 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
583 ph10 345 the class, so got the count wrong. When actually compiling, the reference
584 ph10 340 was subsequently set up correctly.)
585 ph10 345
586 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
587 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
588     other assertions are supported. I have made pcre_dfa_exec() support
589     (*FAIL).
591 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
592 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
593     cannot be changed at match time, I realized I could make a small
594     improvement to matching performance by compiling OP_ALLANY instead of
595     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
596     on the OP_ANY path.
598     17. Compiling pcretest on Windows with readline support failed without the
599 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
600 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
602 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
603 ph10 345 ncurses library to be included for pcretest when ReadLine support is
604     requested, but also to allow for it to be overridden. This patch came from
605     Daniel Bergström.
606 ph10 347
607 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
608 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
609     any errors with the current Unicode tables. Thanks to Peter Kankowski for
610     spotting this.
611 ph10 324
612 ph10 332
613 ph10 319 Version 7.6 28-Jan-08
614 ph10 300 ---------------------
616 ph10 302 1. A character class containing a very large number of characters with
617     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
618     overflow.
619 ph10 309
620     2. Patch to cut out the "long long" test in pcrecpp_unittest when
621     HAVE_LONG_LONG is not defined.
623 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
624 ph10 304 bring them up to date and include new features. This patch includes:
625 ph10 309
626 ph10 304 - Fixed PH's badly added libz and libbz2 support.
627     - Fixed a problem with static linking.
628 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
629 ph10 304 - Fixed dftables problem and added an option.
630     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
632     - Added readline support for pcretest.
633 ph10 309 - Added an listing of the option settings after cmake has run.
635 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
636     "pcre.dll" under mingw when using Configure/Make. I added stuff to
637     Makefile.am that cause it to include this special target, without
638     affecting anything else. Note that the same mingw target plus all
639     the other distribution libraries and programs are now supported
640     when configuring with CMake (see 6 below) instead of with
641     Configure/Make.
642 ph10 309
643 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
644     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
645 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
646     solves the problem, but it does no harm.
647 ph10 313
648 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
649 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
650 ph10 314 with CMake, and also correct the comment about stack recursion.
651 ph10 313
652 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
653 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
654     of a program that users should build themselves after PCRE is installed, so
655     building it automatically is not really right. What is more, it gave
656 ph10 312 trouble in some build environments.
657 ph10 300
658 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
659 ph10 308
660 ph10 319
661 ph10 298 Version 7.5 10-Jan-08
662 ph10 263 ---------------------
664     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
665     values in parens when parsing an RE using the C++ wrapper."
666 ph10 286
667 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
668     Characters greater than 255 were excluded from the class instead of being
669     included.
670 ph10 286
671     3. The same bug as (2) above applied to negated POSIX classes such as
672 ph10 265 [:^space:].
673 ph10 286
674 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
675     defined or documented. It seems to have been a typo for PCRE_STATIC, so
676 ph10 286 I have changed it.
678 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
679 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
680     first named subpattern whose name started with "a" (in other words, the
681 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
682     expected" is now given for (?&) (a zero-length name), and this patch also
683     makes it give the same error for \k'' (previously it complained that that
684     was a reference to a non-existent subpattern).
685 ph10 286
686 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
687 ph10 286 this is right because (?- can be followed by option settings as well as by
688 ph10 269 digits. I have, however, made the messages clearer.
689 ph10 286
690 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
691     than the number used in the conditional) now cause a compile-time error.
692     This is actually not compatible with Perl, which accepts such patterns, but
693     treats the conditional as always being FALSE (as PCRE used to), but it
694     seems to me that giving a diagnostic is better.
695 ph10 286
696 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
697 ph10 275 and messages.
698 ph10 286
699     9. Fix two occurrences of "backslash" in comments that should have been
700     "backspace".
702     10. Remove two redundant lines of code that can never be obeyed (their function
703     was moved elsewhere).
705     11. The program that makes PCRE's Unicode character property table had a bug
706     which caused it to generate incorrect table entries for sequences of
707 ph10 277 characters that have the same character type, but are in different scripts.
708 ph10 286 It amalgamated them into a single range, with the script of the first of
709 ph10 277 them. In other words, some characters were in the wrong script. There were
710     thirteen such cases, affecting characters in the following ranges:
711 ph10 286
712 ph10 277 U+002b0 - U+002c1
713     U+0060c - U+0060d
714 ph10 286 U+0061e - U+00612
715 ph10 277 U+0064b - U+0065e
716     U+0074d - U+0076d
717     U+01800 - U+01805
718     U+01d00 - U+01d77
719     U+01d9b - U+01dbf
720     U+0200b - U+0200f
721     U+030fc - U+030fe
722     U+03260 - U+0327f
723     U+0fb46 - U+0fbb1
724     U+10450 - U+1049d
725 ph10 286
726 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
727     compatible with GNU grep in that, if there was more than one match in a
728     line, it showed only the first of them. It now behaves in the same way as
729     GNU grep.
730 ph10 286
731     13. If the -o and -v options were combined for pcregrep, it printed a blank
732     line for every non-matching line. GNU grep prints nothing, and pcregrep now
733     does the same. The return code can be used to tell if there were any
734     non-matching lines.
736 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
738     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
739 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
740 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
741     and both kinds of lookbehind were skipped).
743 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
744 ph10 284 inclusion of <windows.h> to before rather than after the definition of
745     INVALID_FILE_ATTRIBUTES (patch from David Byron).
746 ph10 263
747 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
748 ph10 286 character property caused pcre_compile() to compile bad code, which led at
749     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
750     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
751     caused the error; without that there was no problem.
752 ph10 263
753 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
754 ph10 286
755 ph10 289 19. Added --enable-pcretest-libreadline.
756 ph10 286
757 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
758 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
759 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
760     later patch that removed the other one (the right fix) and added unit tests
761     that check the return values (which was not done before).
762 ph10 292
763 ph10 291 21. Several CMake things:
764 ph10 287
765 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
766 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
767 ph10 288
768 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
769     linked with the newly-built libraries, not previously installed ones.
770 ph10 291
772 ph10 298
773     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
774     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
775     UTF-8 newline character). The key issue is that the pattern starts .*;
776     this means that the match must be either at the beginning, or after a
777     newline. The bug was in the code for advancing after a failed match and
778     checking that the new position followed a newline. It was not taking
779 ph10 294 account of UTF-8 characters correctly.
780 ph10 298
781     23. PCRE was behaving differently from Perl in the way it recognized POSIX
782     character classes. PCRE was not treating the sequence [:...:] as a
783     character class unless the ... were all letters. Perl, however, seems to
784     allow any characters between [: and :], though of course it rejects as
785     unknown any "names" that contain non-letters, because all the known class
786     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
787     for example, whereas PCRE did not - it did not recognize a POSIX character
788     class. This seemed a bit dangerous, so the code has been changed to be
789     closer to Perl. The behaviour is not identical to Perl, because PCRE will
790     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
791     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
792     Perl does, and where it didn't before.
794 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
795     Windows environments %n is disabled by default.
796 ph10 292
798 ph10 260 Version 7.4 21-Sep-07
799 ph10 230 ---------------------
801     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
802 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
803     LF". That isn't really right - the whole point of the change was to try to
804     help when there was an actual mention of one of the two characters. So now
805     the change happens only if \r or \n (or a literal CR or LF) character is
806 ph10 230 encountered.
807 ph10 231
808     2. The 32-bit options word was also used for 6 internal flags, but the numbers
809     of both had grown to the point where there were only 3 bits left.
810     Fortunately, there was spare space in the data structure, and so I have
811     moved the internal flags into a new 16-bit field to free up more option
812 ph10 230 bits.
813 ph10 231
814     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
815     but did not set the internal JCHANGED flag - either of these is enough to
816     control the way the "get" function works - but the PCRE_INFO_JCHANGED
817     facility is supposed to tell if (?J) was ever used, so now (?J) at the
818 ph10 230 start sets both bits.
820 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
821     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
822 ph10 230
823 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
825     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
826 ph10 233 compatibility, even though it is no longer used.
827 ph10 243
828     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
829 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
830 ph10 259 windows.h file is present (where different names are used). [This was
831 ph10 257 reversed later after testing - see 16 below.]
832 ph10 243
833     8. Changed all #include <config.h> to #include "config.h". There were also
834 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
835 ph10 243
836 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
837 ph10 243 sequence off the lines that it output.
839     10. It was pointed out to me that arrays of string pointers cause lots of
840     relocations when a shared library is dynamically loaded. A technique of
841     using a single long string with a table of offsets can drastically reduce
842     these. I have refactored PCRE in four places to do this. The result is
843 ph10 240 dramatic:
844 ph10 243
845 ph10 240 Originally: 290
846     After changing UCP table: 187
847 ph10 243 After changing error message table: 43
848 ph10 240 After changing table of "verbs" 36
849     After changing table of Posix names 22
850 ph10 243
851 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
852 ph10 247
853 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
854 ph10 247 unicode-properties was also set.
856 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
857 ph10 231
858 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
859     checked only for CRLF.
860 ph10 233
861 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
863 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
864 ph10 253
865 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
866 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
867     entirely. This removes changes made in 7 above.
868 ph10 256
869 ph10 261 17. The CMake files have been updated, and there is now more information about
870     building with CMake in the NON-UNIX-USE document.
871 ph10 257
872 ph10 261
873 ph10 228 Version 7.3 28-Aug-07
874 ph10 157 ---------------------
876 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
877     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
878     brackets there is not right, since it causes compilers to look for an
879     installed pcre.h, not the version that is in the source that is being
880     compiled (which of course may be different). I have changed it back to:
881 ph10 197
882 ph10 189 #include "pcre.h"
883 ph10 197
884     I have a vague recollection that the change was concerned with compiling in
885     different directories, but in the new build system, that is taken care of
886     by the VPATH setting the Makefile.
888 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
889     when the subject happened to end in the byte 0x85 (e.g. if the last
890     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
891     characters but of course it shouldn't be taken as a newline when it is part
892     of another character. The bug was that, for an unlimited repeat of . in
893     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
894     characters when looking for a newline.
895 ph10 197
896     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
898     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
899     in debug output.
901 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
902     long printing in the pcrecpp unittest when running under MinGW.
903 ph10 189
904 ph10 197 6. ESC_K was left out of the EBCDIC table.
905 ph10 189
906 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
907     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
908     limit also applies to "virtual nesting" when a pattern is recursive, and in
909     this case 1000 isn't so big. I have been able to remove this limit at the
910     expense of backing off one optimization in certain circumstances. Normally,
911     when pcre_exec() would call its internal match() function recursively and
912     immediately return the result unconditionally, it uses a "tail recursion"
913     feature to save stack. However, when a subpattern that can match an empty
914     string has an unlimited repetition quantifier, it no longer makes this
915     optimization. That gives it a stack frame in which to save the data for
916     checking that an empty string has been matched. Previously this was taken
917     from the 1000-entry workspace that had been reserved. So now there is no
918     explicit limit, but more stack is used.
919 ph10 189
920 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
921     syntax that is required for Windows, and which was going wrong for the
922     pcreposix and pcrecpp parts of the library. These were overlooked when this
923     problem was solved for the main library.
924 ph10 197
925 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
926     the size of patterns that contain repeated groups with explicit upper
927     limits. As the maximum quantifier is 65535, the maximum group length was
928     set at 30,000 so that the product of these two numbers did not overflow a
929     32-bit integer. However, it turns out that people want to use groups that
930     are longer than 30,000 bytes (though not repeat them that many times).
931     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
932     made it possible to implement the integer overflow checks in a much more
933     dynamic way, which I have now done. The artificial limitation on group
934     length has been removed - we now have only the limit on the total length of
935     the compiled pattern, which depends on the LINK_SIZE setting.
936 ph10 208
937     10. Fixed a bug in the documentation for get/copy named substring when
938     duplicate names are permitted. If none of the named substrings are set, the
939     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
940     empty string.
942     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
943     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
944     because the ] is interpreted as the first data character and the
945     terminating ] is not found. PCRE has been made compatible with Perl in this
946     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
947     cause memory overwriting.
949 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
950     string has been matched (to stop an infinite loop). It was not recognizing
951 ph10 208 a conditional subpattern that could match an empty string if that
952 ph10 206 subpattern was within another subpattern. For example, it looped when
953 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
954 ph10 206 condition was not nested. This bug has been fixed.
955 ph10 208
956 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
957     past the start of the subject in the presence of bytes with the top bit
958     set, for example "\x8aBCD".
959 ph10 211
960 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
961     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
962 ph10 200
963 ph10 211 14. Optimized (?!) to (*FAIL).
964 ph10 202
965 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
966     This restricts code points to be within the range 0 to 0x10FFFF, excluding
967     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
968     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
969     does: it's just the validity check that is more restrictive.
970 ph10 220
971     16. Inserted checks for integer overflows during escape sequence (backslash)
972     processing, and also fixed erroneous offset values for syntax errors during
973     backslash processing.
975 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
976 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
978 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
979     caused an overrun.
980 ph10 220
981     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
982     something other than just ASCII characters) inside a group that had an
983     unlimited repeat caused a loop at compile time (while checking to see
984     whether the group could match an empty string).
986 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
987     [\P{Any}] did so. (Error in the code for printing property names.)
988 ph10 210
989 ph10 220 21. An orphan \E inside a character class could cause a crash.
991     22. A repeated capturing bracket such as (A)? could cause a wild memory
992 ph10 218 reference during compilation.
993 ph10 220
994     23. There are several functions in pcre_compile() that scan along a compiled
995     expression for various reasons (e.g. to see if it's fixed length for look
996 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
997 ph10 220 present in the pattern. These operators have additional parameters compared
998     with \d, etc, and these were not being taken into account when moving along
999 ph10 218 the compiled data. Specifically:
1000 ph10 220
1001     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1002     length.
1004     (b) An item such as \pL+ within a repeated group could cause crashes or
1005 ph10 218 loops.
1006 ph10 220
1007 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1008 ph10 220 "reference to non-existent subpattern" error.
1010 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1012 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1013 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1014 ph10 211
1015 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1016 ph10 218
1017 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1018 ph10 223 character were causing crashes (broken optimization).
1019 ph10 227
1020 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1021 ph10 227 \p or \P) caused a compile-time loop.
1023 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1024     break. For example, the unstudied pattern [\r\n]A does not match the string
1025     "\r\nA" because change 7.0/46 below moves the current point on by two
1026     characters after failing to match at the start. However, the pattern \nA
1027 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1028     the same is true. There doesn't seem any very clean way out of this, but
1029     what I have chosen to do makes the common cases work: PCRE now takes note
1030     of whether there can be an explicit match for \r or \n anywhere in the
1031     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1032     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1033     pattern has explicit CR or LF references.
1034 ph10 222
1035 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1036 ph10 223
1037 ph10 227
1038 ph10 189 Version 7.2 19-Jun-07
1039     ---------------------
1041 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1042     which is apparently normally available under Windows.
1043 ph10 159
1044     2. Re-jig the pcregrep tests with different newline settings in an attempt
1045     to make them independent of the local environment's newline setting.
1046 ph10 157
1047 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1048 ph10 165
1049 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1050     was not 2, because the output contained actual offsets. The recent new
1051 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1052     usable with all link sizes.
1054 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1055     stack recursion. This gives a massive performance boost under BSD, but just
1056 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1057 ph10 164 in all cases.
1058 ph10 172
1059 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1060 ph10 172
1061 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1062     recursion call. It refers to the nth most recently opened parentheses.
1063 ph10 172
1064 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1065 ph10 172 to be opened parentheses.
1067     (c) Conditions that refer to capturing parentheses can be specified
1068 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1069 ph10 172
1070 ph10 168 (d) \K resets the start of the current match so that everything before
1071 ph10 172 is not part of it.
1073 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1074 ph10 172
1075 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1076 ph10 172 reference syntax.
1077 ph10 182
1078 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1079 ph10 182 alternative starts with the same number.
1080 ph10 172
1081 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1083 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1086     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1087     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1088 ph10 170 for detecting groups that can match an empty string.
1089 ph10 159
1090 ph10 172 9. A pattern with a very large number of alternatives (more than several
1091     hundred) was running out of internal workspace during the pre-compile
1092     phase, where pcre_compile() figures out how much memory will be needed. A
1093     bit of new cunning has reduced the workspace needed for groups with
1094     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1095     workspace instead of running out of the 4096 that are available.
1096 ph10 182
1097 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1098 ph10 172
1099 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1100     The report of the bug said:
1101 ph10 182
1102 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1103     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1104 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1105 ph10 185
1106 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1107 ph10 185 it matched the wrong number of bytes.
1108 ph10 172
1109 ph10 179
1110 ph10 155 Version 7.1 24-Apr-07
1111 ph10 98 ---------------------
1113 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1114 ph10 122 that is more "standard", making use of automake and other Autotools. There
1115 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1116     on this.
1117 ph10 111
1118     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1119     for recursive directory scanning broke on some systems because the files
1120     are not scanned in any specific order and on different systems the order
1121     was different. A call to "sort" has been inserted into RunGrepTest for the
1122     approprate test as a short-term fix. In the longer term there may be an
1123 ph10 100 alternative.
1124 ph10 111
1125 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1126 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1127     people do their own conversions for various reasons). The problems
1128     concerned the use of low-level troff macros .br and .in. I have therefore
1129     removed all such uses from the man pages (some were redundant, some could
1130 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1131     HTML has been updated to handle .nf/.fi and to complain if it encounters
1132     .br or .in.
1133 ph10 111
1134 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1135 ph10 123 arranged for config.h to be included in the distribution, with the name
1136 ph10 111 config.h.generic, for the benefit of those who have to compile without
1137     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1139     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1140     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1141 ph10 127 makevp.bat for the current PCRE, using the additional files
1142 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1143 ph10 111
1144     6. A Windows user reported a minor discrepancy with test 2, which turned out
1145     to be caused by a trailing space on an input line that had got lost in his
1146 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1147 ph10 111
1148 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1149 ph10 111 that is needed.
1151 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1152     as "const" (a) because they are and (b) because it helps the PHP
1153     maintainers who have recently made a script to detect big data structures
1154 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1155     to update Builducptable as well, so it won't revert if ucptable.h is ever
1156 ph10 105 re-created.
1157 ph10 111
1158     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1159 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1160 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1161     support is not required. This saves 1.5-2K of code, which is important in
1162 ph10 107 some applications.
1163 ph10 111
1164 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1165 ph10 111 so as not to refer to the tables, even though these functions will never be
1166     called when UTF-8 support is disabled. Otherwise there are problems with a
1167     shared library.
1169 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1171     (a) It was defining its arguments as char * instead of void *.
1173 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1174     a long time ago when I wrote it, but is no longer the case.
1176 ph10 118 The emulated memove() is provided for those environments that have neither
1177 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1178 ph10 118 is clearly not the case, as these two bugs were recently reported.
1179 ph10 123
1180 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1181 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1182     pages, and it removes trailing spaces from listed files. It also creates
1183     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1184     case, it wraps all the #defines with #ifndefs. This script should be run
1185 ph10 111 before "make dist".
1186 ph10 123
1187 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1188     with Unicode property support.
1189 ph10 123
1190     (a) For a maximizing quantifier, if the two different cases of the
1191     character were of different lengths in their UTF-8 codings (there are
1192     some cases like this - I found 11), and the matching function had to
1193 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1194     were both the same length.
1195 ph10 123
1196     (b) When PCRE was configured to use the heap rather than the stack for
1197     recursion during matching, it was not correctly preserving the data for
1198     the other case of a UTF-8 character when checking ahead for a match
1199     while processing a minimizing repeat. If the check also involved
1200 ph10 115 matching a wide character, but failed, corruption could cause an
1201     erroneous result when trying to check for a repeat of the original
1202     character.
1203 ph10 123
1204 ph10 116 13. Some tidying changes to the testing mechanism:
1205 ph10 98
1206 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1207     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1208 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1209     this for UTF-8.) The configure.ac script no longer substitutes the
1210     relevant variables.
1212 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1213     with length and offset values. This means that the output is different
1214     for different internal link sizes. Test 2 is skipped for link sizes
1215     other than 2 because of this, bypassing the problem. Unfortunately,
1216     there was also a test in test 3 (the locale tests) that used /B and
1217 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1218     I have added a new /Z option to pcretest that replaces the length and
1219     offset values with spaces. This is now used to make test 3 independent
1220 ph10 122 of link size. (Test 2 will be tidied up later.)
1221 ph10 123
1222     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1223 ph10 122 segmentation fault instead of returning the appropriate error message.
1224 ph10 134
1225 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1226 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1227     This doesn't seem right; it now treats the CRLF combination as the line
1228     ending, and so does not match in that case. It's only a pattern such as ^$
1229     that would hit this one: something like ^ABC$ would have failed after \r
1230     and then tried again after \r\n.
1232 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1233 ph10 134 in an attempt to make files that differ only in their line terminators
1234     compare equal. This works on Linux.
1235 ph10 142
1236 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1237     as it exited. This is now fixed, thanks to valgrind.
1238 ph10 142
1239 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1240 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1241     was because its rules for how to advance for /g after matching an empty
1242 ph10 143 string at the end of a line did not allow for this case. They now check for
1243     it specially.
1244 ph10 150
1245     20. pcretest is supposed to handle patterns and data of any length, by
1246     extending its buffers when necessary. It was getting this wrong when the
1247 ph10 147 buffer for a data line had to be extended.
1248 ph10 150
1249 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1250 ph10 150 CRLF as a newline sequence.
1251 ph10 152
1252 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1253 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1254     I have nevertheless tidied it up.
1255 ph10 111
1256 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1257 ph10 123
1258 ph10 153 24. Added a man page for pcre-config.
1259 ph10 152
1260 ph10 153
1261 nigel 93 Version 7.0 19-Dec-06
1262     ---------------------
1264     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1265     moving to gcc 4.1.1.
1267     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1268     sys/time.h, which is documented as needed for this function. It doesn't
1269     seem to matter on Linux, but it showed up on some releases of OS X.
1271     3. It seems that there are systems where bytes whose values are greater than
1272     127 match isprint() in the "C" locale. The "C" locale should be the
1273     default when a C program starts up. In most systems, only ASCII printing
1274     characters match isprint(). This difference caused the output from pcretest
1275     to vary, making some of the tests fail. I have changed pcretest so that:
1277     (a) When it is outputting text in the compiled version of a pattern, bytes
1278     other than 32-126 are always shown as hex escapes.
1280     (b) When it is outputting text that is a matched part of a subject string,
1281     it does the same, unless a different locale has been set for the match
1282     (using the /L modifier). In this case, it uses isprint() to decide.
1284     4. Fixed a major bug that caused incorrect computation of the amount of memory
1285     required for a compiled pattern when options that changed within the
1286     pattern affected the logic of the preliminary scan that determines the
1287     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1288     that the computed length was too small. The symptoms of this bug were
1289     either the PCRE error "internal error: code overflow" from pcre_compile(),
1290     or a glibc crash with a message such as "pcretest: free(): invalid next
1291     size (fast)". Examples of patterns that provoked this bug (shown in
1292     pcretest format) are:
1294     /(?-x: )/x
1295     /(?x)(?-x: \s*#\s*)/
1296     /((?i)[\x{c0}])/8
1297     /(?i:[\x{c0}])/8
1299     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1300     is now done differently.
1302     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1303     wrapper classes; (b) implement a new function in the C++ scanner that is
1304     more efficient than the old way of doing things because it avoids levels of
1305     recursion in the regex matching; (c) add a paragraph to the documentation
1306     for the FullMatch() function.
1308     6. The escape sequence \n was being treated as whatever was defined as
1309     "newline". Not only was this contrary to the documentation, which states
1310     that \n is character 10 (hex 0A), but it also went horribly wrong when
1311     "newline" was defined as CRLF. This has been fixed.
1313     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1314     was being set to -1 for the "end of line" case (supposedly a value that no
1315     character can have). Though this value is never used (the check for end of
1316     line is "zero bytes in current character"), it caused compiler complaints.
1317     I've changed it to 0xffffffff.
1319     8. In pcre_version.c, the version string was being built by a sequence of
1320     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1321     string (as it is for production releases) called a macro with an empty
1322     argument. The C standard says the result of this is undefined. The gcc
1323     compiler treats it as an empty string (which was what was wanted) but it is
1324     reported that Visual C gives an error. The source has been hacked around to
1325     avoid this problem.
1327     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1328     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1329     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1330     of them did).
1332     10. Originally, pcretest opened its input and output without "b"; then I was
1333     told that "b" was needed in some environments, so it was added for release
1334     5.0 to both the input and output. (It makes no difference on Unix-like
1335     systems.) Later I was told that it is wrong for the input on Windows. I've
1336     now abstracted the modes into two macros, to make it easier to fiddle with
1337     them, and removed "b" from the input mode under Windows.
1339     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1341     12. Added -help and --help to pcretest as an official way of being reminded
1342     of the options.
1344     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1345     and pcrecpp.cc because they annoy compilers at high warning levels.
1347     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1349     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1350     scripts are not C programs :-) and which was not noticed because it works
1351     on Linux.
1353     16. pcretest is supposed to handle any length of pattern and data line (as one
1354     line or as a continued sequence of lines) by extending its input buffer if
1355     necessary. This feature was broken for very long pattern lines, leading to
1356     a string of junk being passed to pcre_compile() if the pattern was longer
1357     than about 50K.
1359     17. I have done a major re-factoring of the way pcre_compile() computes the
1360     amount of memory needed for a compiled pattern. Previously, there was code
1361     that made a preliminary scan of the pattern in order to do this. That was
1362     OK when PCRE was new, but as the facilities have expanded, it has become
1363     harder and harder to keep it in step with the real compile phase, and there
1364     have been a number of bugs (see for example, 4 above). I have now found a
1365     cunning way of running the real compile function in a "fake" mode that
1366     enables it to compute how much memory it would need, while actually only
1367     ever using a few hundred bytes of working memory and without too many
1368     tests of the mode. This should make future maintenance and development
1369     easier. A side effect of this work is that the limit of 200 on the nesting
1370     depth of parentheses has been removed (though this was never a serious
1371     limitation, I suspect). However, there is a downside: pcre_compile() now
1372     runs more slowly than before (30% or more, depending on the pattern). I
1373     hope this isn't a big issue. There is no effect on runtime performance.
1375     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1376     newline (only possible for the last line of a file) and it was a
1377     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1379     19. Added additional timing features to pcretest. (1) The -tm option now times
1380     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1381     separate command line item, by a number that specifies the number of
1382     repeats to use when timing. The default is 50000; this gives better
1383     precision, but takes uncomfortably long for very large patterns.
1385     20. Extended pcre_study() to be more clever in cases where a branch of a
1386     subpattern has no definite first character. For example, (a*|b*)[cd] would
1387     previously give no result from pcre_study(). Now it recognizes that the
1388     first character must be a, b, c, or d.
1390     21. There was an incorrect error "recursive call could loop indefinitely" if
1391     a subpattern (or the entire pattern) that was being tested for matching an
1392     empty string contained only one non-empty item after a nested subpattern.
1393     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1394     incorrectly, because the \d was being skipped in the check.
1396     22. The pcretest program now has a new pattern option /B and a command line
1397     option -b, which is equivalent to adding /B to every pattern. This causes
1398     it to show the compiled bytecode, without the additional information that
1399     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1400     is the same as /B/I).
1402     23. A new optimization is now able automatically to treat some sequences such
1403     as a*b as a*+b. More specifically, if something simple (such as a character
1404     or a simple class like \d) has an unlimited quantifier, and is followed by
1405     something that cannot possibly match the quantified thing, the quantifier
1406     is automatically "possessified".
1408     24. A recursive reference to a subpattern whose number was greater than 39
1409     went wrong under certain circumstances in UTF-8 mode. This bug could also
1410     have affected the operation of pcre_study().
1412     25. Realized that a little bit of performance could be had by replacing
1413     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1415     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1417     27. Possessive quantifiers such as a++ were previously implemented by turning
1418     them into atomic groups such as ($>a+). Now they have their own opcodes,
1419     which improves performance. This includes the automatically created ones
1420     from 23 above.
1422     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1423     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1424     the first matched character to be a colon. This applied both to named and
1425     numbered groups.
1427     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1429     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1430     building PCRE on Windows easier, so I have included it in the distribution.
1432     31. There is now a check in pcretest against a ridiculously large number being
1433     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1434     loop, the loop is abandoned.
1436     32. Forward references to subpatterns in conditions such as (?(2)...) where
1437     subpattern 2 is defined later cause pcre_compile() to search forwards in
1438     the pattern for the relevant set of parentheses. This search went wrong
1439     when there were unescaped parentheses in a character class, parentheses
1440     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1442     33. "Subroutine" calls and backreferences were previously restricted to
1443     referencing subpatterns earlier in the regex. This restriction has now
1444     been removed.
1446     34. Added a number of extra features that are going to be in Perl 5.10. On the
1447     whole, these are just syntactic alternatives for features that PCRE had
1448     previously implemented using the Python syntax or my own invention. The
1449     other formats are all retained for compatibility.
1451     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1452     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1453     also .NET compatible.
1455     (b) A recursion or subroutine call to a named group can now be defined as
1456     (?&name) as well as (?P>name).
1458     (c) A backreference to a named group can now be defined as \k<name> or
1459     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1460     5.10, are also .NET compatible.
1462     (d) A conditional reference to a named group can now use the syntax
1463     (?(<name>) or (?('name') as well as (?(name).
1465     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1466     groups (named and numbered) that are never evaluated inline, but can be
1467     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1468     is always false. There may be only one alternative in such a group.
1470     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1471     as the simple (?(R). The condition is true only if the most recent
1472     recursion is that of the given number or name. It does not search out
1473     through the entire recursion stack.
1475     (g) The escape \gN or \g{N} has been added, where N is a positive or
1476     negative number, specifying an absolute or relative reference.
1478     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1479     some "unreachable code" warnings.
1481     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1482     things, this adds five new scripts.
1484     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1485     There were also incompatibilities regarding the handling of \Q..\E inside
1486     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1487     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1489     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1490     matches an empty string, and forcibly breaks the loop. There were bugs in
1491     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1492     against aaaa the result was just "a" rather than "aaaa", for example. Two
1493     separate and independent bugs (that affected different cases) have been
1494     fixed.
1496     39. Refactored the code to abolish the use of different opcodes for small
1497     capturing bracket numbers. This is a tidy that I avoided doing when I
1498     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1499     The new approach is not only tidier, it makes it possible to reduce the
1500     memory needed to fix the previous bug (38).
1502     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1503     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1504     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1505     mode.
1507     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1508     report.
1510     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1511     copy construction and assignment in the C++ wrapper.
1513     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1514     couple of bugs that could have given wrong results in the "--newline=crlf"
1515     case.
1517     44. Added a number of casts and did some reorganization of signed/unsigned int
1518     variables following suggestions from Dair Grant. Also renamed the variable
1519     "this" as "item" because it is a C++ keyword.
1521     45. Arranged for dftables to add
1523     #include "pcre_internal.h"
1525     to pcre_chartables.c because without it, gcc 4.x may remove the array
1526     definition from the final binary if PCRE is built into a static library and
1527     dead code stripping is activated.
1529     46. For an unanchored pattern, if a match attempt fails at the start of a
1530     newline sequence, and the newline setting is CRLF or ANY, and the next two
1531     characters are CRLF, advance by two characters instead of one.
1534 nigel 91 Version 6.7 04-Jul-06
1535     ---------------------
1537     1. In order to handle tests when input lines are enormously long, pcretest has
1538     been re-factored so that it automatically extends its buffers when
1539     necessary. The code is crude, but this _is_ just a test program. The
1540     default size has been increased from 32K to 50K.
1542     2. The code in pcre_study() was using the value of the re argument before
1543     testing it for NULL. (Of course, in any sensible call of the function, it
1544     won't be NULL.)
1546     3. The memmove() emulation function in pcre_internal.h, which is used on
1547     systems that lack both memmove() and bcopy() - that is, hardly ever -
1548     was missing a "static" storage class specifier.
1550     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1551     containing an extended class (one that cannot be represented by a bitmap
1552     because it contains high-valued characters or Unicode property items, e.g.
1553     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1554     pattern, but PCRE should not loop if you do not (it no longer does).
1555     [Detail: two cases were found: (a) a repeated subpattern containing an
1556     extended class; (b) a recursive reference to a subpattern that followed a
1557     previous extended class. It wasn't skipping over the extended class
1558     correctly when UTF-8 mode was not set.]
1560     5. A negated single-character class was not being recognized as fixed-length
1561     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1562     compile error "lookbehind assertion is not fixed length".
1564     6. The RunPerlTest auxiliary script was showing an unexpected difference
1565     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1566     write a Perl script that can interpret lines of an input file either as
1567     byte characters or as UTF-8, which is what "perltest" was being required to
1568     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1569     can't do is switch easily at run time between having the "use utf8;" pragma
1570     or not. In the end, I fudged it by using the RunPerlTest script to insert
1571     "use utf8;" explicitly for the UTF-8 tests.
1573     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1574     the end of the subject string, contrary to the documentation and to what
1575     Perl does. This was true of both matching functions. Now it matches only at
1576     the start of the subject and immediately after *internal* newlines.
1578     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1579     a pointer to an int instead of a pointer to an unsigned long int. This
1580     caused problems on 64-bit systems.
1582     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1583     instance of the 'standard' template library not being so standard".
1585     10. There was no check on the number of named subpatterns nor the maximum
1586     length of a subpattern name. The product of these values is used to compute
1587     the size of the memory block for a compiled pattern. By supplying a very
1588     long subpattern name and a large number of named subpatterns, the size
1589     computation could be caused to overflow. This is now prevented by limiting
1590     the length of names to 32 characters, and the number of named subpatterns
1591     to 10,000.
1593     11. Subpatterns that are repeated with specific counts have to be replicated in
1594     the compiled pattern. The size of memory for this was computed from the
1595     length of the subpattern and the repeat count. The latter is limited to
1596     65535, but there was no limit on the former, meaning that integer overflow
1597     could in principle occur. The compiled length of a repeated subpattern is
1598     now limited to 30,000 bytes in order to prevent this.
1600     12. Added the optional facility to have named substrings with the same name.
1602     13. Added the ability to use a named substring as a condition, using the
1603     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1604     are numbers (not recommended). Forward references are permitted.
1606     14. Added forward references in named backreferences (if you see what I mean).
1608     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1609     pattern could run off the end of the subject. For example, the pattern
1610     "(?s)(.{1,5})"8 did this with the subject "ab".
1612     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1613     PCRE_CASELESS was set when matching characters that were quantified with ?
1614     or *.
1616     17. A character class other than a single negated character that had a minimum
1617     but no maximum quantifier - for example [ab]{6,} - was not handled
1618     correctly by pce_dfa_exec(). It would match only one character.
1620     18. A valid (though odd) pattern that looked like a POSIX character
1621     class but used an invalid character after [ (for example [[,abc,]]) caused
1622     pcre_compile() to give the error "Failed: internal error: code overflow" or
1623     in some cases to crash with a glibc free() error. This could even happen if
1624     the pattern terminated after [[ but there just happened to be a sequence of
1625     letters, a binary zero, and a closing ] in the memory that followed.
1627     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1628     over the years. Originally (before any Unicode support), just the bottom 8
1629     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1630     output from "man perlunicode" includes this:
1632     The regular expression compiler produces polymorphic opcodes. That
1633     is, the pattern adapts to the data and automatically switches to
1634     the Unicode character scheme when presented with Unicode data--or
1635     instead uses a traditional byte scheme when presented with byte
1636     data.
1638     Sadly, a wide octal escape does not cause a switch, and in a string with
1639     no other multibyte characters, these octal escapes are treated as before.
1640     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1641     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1642     Unicode string.
1644     I have not perpetrated such confusion in PCRE. Up till now, it took just
1645     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1646     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1647     translate to the appropriate multibyte character.
1649     29. Applied some refactoring to reduce the number of warnings from Microsoft
1650     and Borland compilers. This has included removing the fudge introduced
1651     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1652     a warning about an unused variable.
1654     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1655     characters since release 4.0, because Perl (from release 5.004) does not.
1656     [Or at least, is documented not to: some releases seem to be in conflict
1657     with the documentation.] However, when a pattern was studied with
1658     pcre_study() and all its branches started with \s, PCRE still included VT
1659     as a possible starting character. Of course, this did no harm; it just
1660     caused an unnecessary match attempt.
1662     22. Removed a now-redundant internal flag bit that recorded the fact that case
1663     dependency changed within the pattern. This was once needed for "required
1664     byte" processing, but is no longer used. This recovers a now-scarce options
1665     bit. Also moved the least significant internal flag bit to the most-
1666     significant bit of the word, which was not previously used (hangover from
1667     the days when it was an int rather than a uint) to free up another bit for
1668     the future.
1670     23. Added support for CRLF line endings as well as CR and LF. As well as the
1671     default being selectable at build time, it can now be changed at runtime
1672     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1673     specify that it is scanning data with non-default line endings.
1675     24. Changed the definition of CXXLINK to make it agree with the definition of
1676     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1678     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1679     recursions. This makes a big different to stack usage for some patterns.
1681     26. If a subpattern containing a named recursion or subroutine reference such
1682     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1683     the space required for the compiled pattern went wrong and gave too small a
1684     value. Depending on the environment, this could lead to "Failed: internal
1685     error: code overflow at offset 49" or "glibc detected double free or
1686     corruption" errors.
1688     27. Applied patches from Google (a) to support the new newline modes and (b) to
1689     advance over multibyte UTF-8 characters in GlobalReplace.
1691     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1692     difference for some implementation of PCRE in some Windows version.
1694     29. Added some extra testing facilities to pcretest:
1696     \q<number> in a data line sets the "match limit" value
1697     \Q<number> in a data line sets the "match recursion limt" value
1698     -S <number> sets the stack size, where <number> is in megabytes
1700     The -S option isn't available for Windows.
1703 nigel 89 Version 6.6 06-Feb-06
1704     ---------------------
1706     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1707     in pcreposix.h. I have copied the definition from pcre.h.
1709     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1710     because pcre.h is no longer a built file.
1712     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1713     not normally included in the compiled code.
1716 nigel 87 Version 6.5 01-Feb-06
1717     ---------------------
1719     1. When using the partial match feature with pcre_dfa_exec(), it was not
1720     anchoring the second and subsequent partial matches at the new starting
1721     point. This could lead to incorrect results. For example, with the pattern
1722     /1234/, partially matching against "123" and then "a4" gave a match.
1724     2. Changes to pcregrep:
1726     (a) All non-match returns from pcre_exec() were being treated as failures
1727     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1728     error message is output. Some extra information is given for the
1730     probably the only errors that are likely to be caused by users (by
1731     specifying a regex that has nested indefinite repeats, for instance).
1732     If there are more than 20 of these errors, pcregrep is abandoned.
1734     (b) A binary zero was treated as data while matching, but terminated the
1735     output line if it was written out. This has been fixed: binary zeroes
1736     are now no different to any other data bytes.
1738     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1739     used to set a locale for matching. The --locale=xxxx long option has
1740     been added (no short equivalent) to specify a locale explicitly on the
1741     pcregrep command, overriding the environment variables.
1743     (d) When -B was used with -n, some line numbers in the output were one less
1744     than they should have been.
1746     (e) Added the -o (--only-matching) option.
1748     (f) If -A or -C was used with -c (count only), some lines of context were
1749     accidentally printed for the final match.
1751     (g) Added the -H (--with-filename) option.
1753     (h) The combination of options -rh failed to suppress file names for files
1754     that were found from directory arguments.
1756     (i) Added the -D (--devices) and -d (--directories) options.
1758     (j) Added the -F (--fixed-strings) option.
1760     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1762     (l) Added the --colo(u)r option.
1764     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1765     is not present by default.
1767     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1768     items such as (?R) or (?1), when the recursion could match a number of
1769     alternatives. If it matched one of the alternatives, but subsequently,
1770     outside the recursion, there was a failure, the code tried to back up into
1771     the recursion. However, because of the way PCRE is implemented, this is not
1772     possible, and the result was an incorrect result from the match.
1774     In order to prevent this happening, the specification of recursion has
1775     been changed so that all such subpatterns are automatically treated as
1776     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1778     4. I had overlooked the fact that, in some locales, there are characters for
1779     which isalpha() is true but neither isupper() nor islower() are true. In
1780     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1781     and ordfeminine) are like this. This affected the treatment of \w and \W
1782     when they appeared in character classes, but not when they appeared outside
1783     a character class. The bit map for "word" characters is now created
1784     separately from the results of isalnum() instead of just taking it from the
1785     upper, lower, and digit maps. (Plus the underscore character, of course.)
1787     5. The above bug also affected the handling of POSIX character classes such as
1788     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1789     permanent tables. Instead, the bit maps for such a class were previously
1790     created as the appropriate unions of the upper, lower, and digit bitmaps.
1791     Now they are created by subtraction from the [[:word:]] class, which has
1792     its own bitmap.
1794     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1795     It is created by subtracting the vertical space characters (\x09, \x0a,
1796     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1797     subtraction was done in the overall bitmap for a character class, meaning
1798     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1799     be recognized. This bug has been fixed.
1801     7. Patches from the folks at Google:
1803     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1804     real life, but is still worth protecting against".
1806     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1807     regular expressions".
1809     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1810     have it.
1812     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1813     "configure" and the latter not, in order to fix a problem somebody had
1814     with compiling the Arg class on HP-UX.
1816     (e) Improve the error-handling of the C++ wrapper a little bit.
1818     (f) New tests for checking recursion limiting.
1820     8. The pcre_memmove() function, which is used only if the environment does not
1821     have a standard memmove() function (and is therefore rarely compiled),
1822     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1823     returning a result (though PCRE never actually uses the result).
1825     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1826     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1827     returned instead of calling malloc() with an overflowing number that would
1828     most likely cause subsequent chaos.
1830     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1832     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1833     with this option is matched, the nmatch and pmatch options of regexec() are
1834     ignored.
1836     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1837     provided in case anyone wants to the the POSIX interface with UTF-8
1838     strings.
1840     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1841     C++ linking (needed for some HP-UX environments).
1843     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1844     (unused parameter) and in the pcre_printint() function (omitted "default"
1845     switch label when the default is to do nothing).
1847     15. Added some code to make it possible, when PCRE is compiled as a C++
1848     library, to replace subject pointers for pcre_exec() with a smart pointer
1849     class, thus making it possible to process discontinuous strings.
1851     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1852     much the same function. They were added by different people who were trying
1853     to make PCRE easy to compile on non-Unix systems. It has been suggested
1854     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1855     for compiling on Windows systems. I have therefore replaced it with
1856     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1857     defaults to "extern" for C or "extern C" for C++, which works fine on
1858     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1859     SCOPE with something explicit in config.h. In addition:
1861     (a) pcreposix.h still had just "extern" instead of either of these macros;
1862     I have replaced it with PCRE_DATA_SCOPE.
1864     (b) Functions such as _pcre_xclass(), which are internal to the library,
1865     but external in the C sense, all had PCRE_EXPORT in their definitions.
1866     This is apparently wrong for the Windows case, so I have removed it.
1867     (It makes no difference on Unix-like systems.)
1869     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1870     of recursive calls to match(). This is different to MATCH_LIMIT because
1871     that limits the total number of calls to match(), not all of which increase
1872     the depth of recursion. Limiting the recursion depth limits the amount of
1873     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1874     when PCRE is compiled, and changed at run time. A patch from Google adds
1875     this functionality to the C++ interface.
1877     18. Changes to the handling of Unicode character properties:
1879     (a) Updated the table to Unicode 4.1.0.
1881     (b) Recognize characters that are not in the table as "Cn" (undefined).
1883     (c) I revised the way the table is implemented to a much improved format
1884     which includes recognition of ranges. It now supports the ranges that
1885     are defined in UnicodeData.txt, and it also amalgamates other
1886     characters into ranges. This has reduced the number of entries in the
1887     table from around 16,000 to around 3,000, thus reducing its size
1888     considerably. I realized I did not need to use a tree structure after
1889     all - a binary chop search is just as efficient. Having reduced the
1890     number of entries, I extended their size from 6 bytes to 8 bytes to
1891     allow for more data.
1893     (d) Added support for Unicode script names via properties such as \p{Han}.
1895     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1896     matching that character.
1898     20. When matching a repeated Unicode property with a minimum greater than zero,
1899     (for example \pL{2,}), PCRE could look past the end of the subject if it
1900     reached it while seeking the minimum number of characters. This could
1901     happen only if some of the characters were more than one byte long, because
1902     there is a check for at least the minimum number of bytes.
1904     21. Refactored the implementation of \p and \P so as to be more general, to
1905     allow for more different types of property in future. This has changed the
1906     compiled form incompatibly. Anybody with saved compiled patterns that use
1907     \p or \P will have to recompile them.
1909     22. Added "Any" and "L&" to the supported property types.
1911     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1912     but give a compile time error if the value is greater than 0xff.
1914     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1915     accidentally not being installed or uninstalled.
1917     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1918     made were to insert the current release number. This seemed silly, because
1919     it made things harder for people building PCRE on systems that don't run
1920     "configure". I have turned pcre.h into a distributed file, no longer built
1921     by "configure", with the version identification directly included. There is
1922     no longer a pcre.h.in file.
1924     However, this change necessitated a change to the pcre-config script as
1925     well. It is built from pcre-config.in, and one of the substitutions was the
1926     release number. I have updated configure.ac so that ./configure now finds
1927     the release number by grepping pcre.h.
1929     26. Added the ability to run the tests under valgrind.
1932 nigel 85 Version 6.4 05-Sep-05
1933     ---------------------
1935     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1936     "--" to be printed when multiple files were scanned, even when none of the
1937     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1938     consider it to be a bug, and have restored the previous behaviour.
1940     2. A couple of code tidies to get rid of compiler warnings.
1942     3. The pcretest program used to cheat by referring to symbols in the library
1943     whose names begin with _pcre_. These are internal symbols that are not
1944     really supposed to be visible externally, and in some environments it is
1945     possible to suppress them. The cheating is now confined to including
1946     certain files from the library's source, which is a bit cleaner.
1948     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1949     file's purpose clearer.
1951     5. Reorganized pcre_ucp_findchar().
1954 nigel 83 Version 6.3 15-Aug-05
1955     ---------------------
1957     1. The file libpcre.pc.in did not have general read permission in the tarball.
1959     2. There were some problems when building without C++ support:
1961     (a) If C++ support was not built, "make install" and "make test" still
1962     tried to test it.
1964     (b) There were problems when the value of CXX was explicitly set. Some
1965     changes have been made to try to fix these, and ...
1967     (c) --disable-cpp can now be used to explicitly disable C++ support.
1969     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1970     backslash in a target when C++ was disabled. This confuses some
1971     versions of "make", apparently. Using an intermediate variable solves
1972     this. (Same for CPP_LOBJ.)
1974     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1975     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1976     necessary on certain architectures.
1978     4. Added a setting of -export-symbols-regex to the link command to remove
1979     those symbols that are exported in the C sense, but actually are local
1980     within the library, and not documented. Their names all begin with
1981     "_pcre_". This is not a perfect job, because (a) we have to except some
1982     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1983     available (and never for static libraries). I have made a note to try to
1984     find a way round (a) in the future.
1987 nigel 81 Version 6.2 01-Aug-05
1988     ---------------------
1990     1. There was no test for integer overflow of quantifier values. A construction
1991     such as {1111111111111111} would give undefined results. What is worse, if
1992     a minimum quantifier for a parenthesized subpattern overflowed and became
1993     negative, the calculation of the memory size went wrong. This could have
1994     led to memory overwriting.
1996     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1998     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1999     operating environments where this matters.
2001     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2002     PCRE options from within the C++ wrapper.
2004     5. Named capturing subpatterns were not being correctly counted when a pattern
2005     was compiled. This caused two problems: (a) If there were more than 100
2006     such subpatterns, the calculation of the memory needed for the whole
2007     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2008     back references of the form \12, where the number was greater than 9, were
2009     not recognized as back references, even though there were sufficient
2010     previous subpatterns.
2012     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2013     versions of gcc, e.g. 2.95.4.
2016 nigel 79 Version 6.1 21-Jun-05
2017     ---------------------
2019     1. There was one reference to the variable "posix" in pcretest.c that was not
2020     surrounded by "#if !defined NOPOSIX".
2022     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2023     the cross-check on the old pcre_info() function, for the benefit of the
2024     cut-down version of PCRE that is currently imported into Exim.
2026     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2027     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2028     patterns that start (?i) but I don't think that matters. The use of (?i) is
2029     just an example; this all applies to the other options as well.
2031     4. Since libtool seems to echo the compile commands it is issuing, the output
2032     from "make" can be reduced a bit by putting "@" in front of each libtool
2033     compile command.
2035     5. Patch from the folks at Google for configure.in to be a bit more thorough
2036     in checking for a suitable C++ installation before trying to compile the
2037     C++ stuff. This should fix a reported problem when a compiler was present,
2038     but no suitable headers.
2040     6. The man pages all had just "PCRE" as their title. I have changed them to
2041     be the relevant file name. I have also arranged that these names are
2042     retained in the file doc/pcre.txt, which is a concatenation in text format
2043     of all the man pages except the little individual ones for each function.
2045     7. The NON-UNIX-USE file had not been updated for the different set of source
2046     files that come with release 6. I also added a few comments about the C++
2047     wrapper.
2050 nigel 77 Version 6.0 07-Jun-05
2051     ---------------------
2053     1. Some minor internal re-organization to help with my DFA experiments.
2055     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2056     didn't matter for the library itself when fully configured, but did matter
2057     when compiling without UCP support, or within Exim, where the ucp files are
2058     not imported.
2060     3. Refactoring of the library code to split up the various functions into
2061     different source modules. The addition of the new DFA matching code (see
2062     below) to a single monolithic source would have made it really too
2063     unwieldy, quite apart from causing all the code to be include in a
2064     statically linked application, when only some functions are used. This is
2065     relevant even without the DFA addition now that patterns can be compiled in
2066     one application and matched in another.
2068     The downside of splitting up is that there have to be some external
2069     functions and data tables that are used internally in different modules of
2070     the library but which are not part of the API. These have all had their
2071     names changed to start with "_pcre_" so that they are unlikely to clash
2072     with other external names.
2074     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2075     a different (DFA) algorithm. Although it is slower than the original
2076     function, it does have some advantages for certain types of matching
2077     problem.
2079     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2080     including restarting after a partial match.
2082     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2083     defined when compiling for Windows was sent to me. I have put it into the
2084     code, though I have no means of testing or verifying it.
2086     7. Added the pcre_refcount() auxiliary function.
2088     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2089     match before or at the first newline in the subject string. In pcretest,
2090     the /f option on a pattern can be used to set this.
2092     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2093     would behave wrongly. This has been present in PCRE since release 4.0.
2095     10. A number of changes to the pcregrep command:
2097     (a) Refactored how -x works; insert ^(...)$ instead of setting
2098     PCRE_ANCHORED and checking the length, in preparation for adding
2099     something similar for -w.
2101     (b) Added the -w (match as a word) option.
2103     (c) Refactored the way lines are read and buffered so as to have more
2104     than one at a time available.
2106     (d) Implemented a pcregrep test script.
2108     (e) Added the -M (multiline match) option. This allows patterns to match
2109     over several lines of the subject. The buffering ensures that at least
2110     8K, or the rest of the document (whichever is the shorter) is available
2111     for matching (and similarly the previous 8K for lookbehind assertions).
2113     (f) Changed the --help output so that it now says
2115     -w, --word-regex(p)
2117     instead of two lines, one with "regex" and the other with "regexp"
2118     because that confused at least one person since the short forms are the
2119     same. (This required a bit of code, as the output is generated
2120     automatically from a table. It wasn't just a text change.)
2122     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2123     option but starts with a hyphen. Could be a pattern or a path name
2124     starting with a hyphen, for instance.
2126     (h) "-" can be given as a file name to represent stdin.
2128     (i) When file names are being printed, "(standard input)" is used for
2129     the standard input, for compatibility with GNU grep. Previously
2130     "<stdin>" was used.
2132     (j) The option --label=xxx can be used to supply a name to be used for
2133     stdin when file names are being printed. There is no short form.
2135     (k) Re-factored the options decoding logic because we are going to add
2136     two more options that take data. Such options can now be given in four
2137     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2139     (l) Added the -A, -B, and -C options for requesting that lines of context
2140     around matches be printed.
2142     (m) Added the -L option to print the names of files that do not contain
2143     any matching lines, that is, the complement of -l.
2145     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2146     continue to scan other files.
2148     (o) The -s option was incorrectly implemented. For compatibility with other
2149     greps, it now suppresses the error message for a non-existent or non-
2150     accessible file (but not the return code). There is a new option called
2151     -q that suppresses the output of matching lines, which was what -s was
2152     previously doing.
2154     (p) Added --include and --exclude options to specify files for inclusion
2155     and exclusion when recursing.
2157     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2158     Hopefully, it now does.
2160     12. Missing cast in pcre_study().
2162     13. Added an "uninstall" target to the makefile.
2164     14. Replaced "extern" in the function prototypes in Makefile.in with
2165     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2166     world, but is set differently for Windows.
2168     15. Added a second compiling function called pcre_compile2(). The only
2169     difference is that it has an extra argument, which is a pointer to an
2170     integer error code. When there is a compile-time failure, this is set
2171     non-zero, in addition to the error test pointer being set to point to an
2172     error message. The new argument may be NULL if no error number is required
2173     (but then you may as well call pcre_compile(), which is now just a
2174     wrapper). This facility is provided because some applications need a
2175     numeric error indication, but it has also enabled me to tidy up the way
2176     compile-time errors are handled in the POSIX wrapper.
2178     16. Added VPATH=.libs to the makefile; this should help when building with one
2179     prefix path and installing with another. (Or so I'm told by someone who
2180     knows more about this stuff than I do.)
2182     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2183     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2184     match everything, including newlines. This is not POSIX-compatible, but
2185     somebody wanted the feature. From pcretest it can be activated by using
2186     both the P and the s flags.
2188     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2190     19. libpcre.pc was being incorrectly installed as executable.
2192     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2193     it now also looks for '\r' so that it will work unmodified on Windows.
2195     21. Added Google's contributed C++ wrapper to the distribution.
2197     22. Added some untidy missing memory free() calls in pcretest, to keep
2198     Electric Fence happy when testing.
2202 nigel 75 Version 5.0 13-Sep-04
2203     ---------------------
2205     1. Internal change: literal characters are no longer packed up into items
2206     containing multiple characters in a single byte-string. Each character
2207     is now matched using a separate opcode. However, there may be more than one
2208     byte in the character in UTF-8 mode.
2210     2. The pcre_callout_block structure has two new fields: pattern_position and
2211     next_item_length. These contain the offset in the pattern to the next match
2212     item, and its length, respectively.
2214     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2215     insertion of callouts before each pattern item. Added the /C option to
2216     pcretest to make use of this.
2218     4. On the advice of a Windows user, the lines
2220     #if defined(_WIN32) || defined(WIN32)
2221     _setmode( _fileno( stdout ), 0x8000 );
2222     #endif /* defined(_WIN32) || defined(WIN32) */
2224     have been added to the source of pcretest. This apparently does useful
2225     magic in relation to line terminators.
2227     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2228     for the benefit of those environments where the "b" makes a difference.
2230     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2231     to know about it. I have put a hack into configure.in that adds in code
2232     to set GCC=yes if CC=icc. This seems to end up at a point in the
2233     generated configure script that is early enough to affect the setting of
2234     compiler options, which is what is needed, but I have no means of testing
2235     whether it really works. (The user who reported this had patched the
2236     generated configure script, which of course I cannot do.)
2238     LATER: After change 22 below (new libtool files), the configure script
2239     seems to know about icc (and also ecc). Therefore, I have commented out
2240     this hack in configure.in.
2242     7. Added support for pkg-config (2 patches were sent in).
2244     8. Negated POSIX character classes that used a combination of internal tables
2245     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2246     [[:^ascii]]. Typically, they would match almost any characters. The other
2247     POSIX classes were not broken in this way.
2249     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2250     to find the match, as PCRE was deluded into thinking that the match had to
2251     start at the start point or following a newline. The same bug applied to
2252     patterns with negative forward assertions or any backward assertions
2253     preceding ".*" at the start, unless the pattern required a fixed first
2254     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2256     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2257     starting at the last subject character, bytes beyond the end of the subject
2258     string were read.
2260     11. Renamed the variable "class" as "classbits" to make life easier for C++
2261     users. (Previously there was a macro definition, but it apparently wasn't
2262     enough.)
2264     12. Added the new field "tables" to the extra data so that tables can be passed
2265     in at exec time, or the internal tables can be re-selected. This allows
2266     a compiled regex to be saved and re-used at a later time by a different
2267     program that might have everything at different addresses.
2269     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2270     -R library as well as a -L library.
2272     14. The debugging options of pcretest (-d on the command line or D on a
2273     pattern) showed incorrect output for anything following an extended class
2274     that contained multibyte characters and which was followed by a quantifier.
2276     15. Added optional support for general category Unicode character properties
2277     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2278     support. It adds about 90K to the size of the library. The meanings of the
2279     inbuilt class escapes such as \d and \s have NOT been changed.
2281     16. Updated pcredemo.c to include calls to free() to release the memory for the
2282     compiled pattern.
2284     17. The generated file chartables.c was being created in the source directory
2285     instead of in the building directory. This caused the build to fail if the
2286     source directory was different from the building directory, and was
2287     read-only.
2289     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2290     file. No doubt somebody will tell me if they don't make sense... Also added
2291     Dan Mooney's comments about building on OpenVMS.
2293     19. Added support for partial matching via the PCRE_PARTIAL option for
2294     pcre_exec() and the \P data escape in pcretest.
2296     20. Extended pcretest with 3 new pattern features:
2298     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2299     write the compiled pattern to the file whose name is "rest-of-line".
2300     This is a straight binary dump of the data, with the saved pointer to
2301     the character tables forced to be NULL. The study data, if any, is
2302     written too. After writing, pcretest reads a new pattern.
2304     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2305     compiled pattern from the given file. There must not be any
2306     occurrences of "<" in the file name (pretty unlikely); if there are,
2307     pcretest will instead treat the initial "<" as a pattern delimiter.
2308     After reading in the pattern, pcretest goes on to read data lines as
2309     usual.
2311     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2312     and 16-bit fields in a compiled pattern, to simulate a pattern that
2313     was compiled on a host of opposite endianness.
2315     21. The pcre-exec() function can now cope with patterns that were compiled on
2316     hosts of opposite endianness, with this restriction:
2318     As for any compiled expression that is saved and used later, the tables
2319     pointer field cannot be preserved; the extra_data field in the arguments
2320     to pcre_exec() should be used to pass in a tables address if a value
2321     other than the default internal tables were used at compile time.
2323     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2324     now diagnosed as an error. Previously, most of the time, a negative number
2325     would have been treated as zero, but if in addition "ovector" was passed as
2326     NULL, a crash could occur.
2328     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2329     new versions from the libtool 1.5 distribution (the last one is a copy of
2330     a file called libtool.m4). This seems to have fixed the need to patch
2331     "configure" to support Darwin 1.3 (which I used to do). However, I still
2332     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2333     workstation).
2335     24. Changed the PCRE licence to be the more standard "BSD" licence.
2338 nigel 73 Version 4.5 01-Dec-03
2339     ---------------------
2341     1. There has been some re-arrangement of the code for the match() function so
2342     that it can be compiled in a version that does not call itself recursively.
2343     Instead, it keeps those local variables that need separate instances for
2344     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2345     needs to "recurse". Keeping track of where control must go is done by means
2346     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2347     hide most of the details from the main code, and operates only if
2348     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2349     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2350     operating.
2352     To make it easier for callers to provide specially tailored get/free
2353     functions for this usage, two new functions, pcre_stack_malloc, and
2354     pcre_stack_free, are used. They are always called in strict stacking order,
2355     and the size of block requested is always the same.
2357     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2358     PCRE has been compiled to use the stack or the heap for recursion. The
2359     -C option of pcretest uses this to show which version is compiled.
2361     A new data escape \S, is added to pcretest; it causes the amounts of store
2362     obtained and freed by both kinds of malloc/free at match time to be added
2363     to the output.
2365     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2366     what's available on my current Linux desktop machine.
2368     3. When matching a UTF-8 string, the test for a valid string at the start has
2369     been extended. If start_offset is not zero, PCRE now checks that it points
2370     to a byte that is the start of a UTF-8 character. If not, it returns
2371     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2372     this is necessary because there may be backward assertions in the pattern.
2373     When matching the same subject several times, it may save resources to use
2374     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2376     4. The code for checking the validity of UTF-8 strings has been tightened so
2377     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2378     containing "overlong sequences".
2380     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2381     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2382     should have been "&", but it just so happened that all the cases this let
2383     through by mistake were picked up later in the function.
2385     6. I had used a variable called "isblank" - this is a C99 function, causing
2386     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2388     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2389     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2390     so the version is shown; (c) stop "make test" echoing "./RunTest".
2392     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2394     9. The prototype for memmove() for systems that don't have it was using
2395     size_t, but the inclusion of the header that defines size_t was later. I've
2396     moved the #includes for the C headers earlier to avoid this.
2398     10. Added some adjustments to the code to make it easier to compiler on certain
2399     special systems:
2401     (a) Some "const" qualifiers were missing.
2402     (b) Added the macro EXPORT before all exported functions; by default this
2403     is defined to be empty.
2404     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2405     that it reads its output file name as an argument instead of writing
2406     to the standard output and assuming this can be redirected.
2408     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2409     class containing characters with values greater than 255, PCRE compilation
2410     went into a loop.
2412     12. A recursive reference to a subpattern that was within another subpattern
2413     that had a minimum quantifier of zero caused PCRE to crash. For example,
2414     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2415     recursion. If the recursively-called subpattern itself had a zero repeat,
2416     that was OK.
2418     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2419     buffer into which it was copied (for escape processing) was still set at
2420     1024, so long lines caused crashes.
2422     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2423     "internal error: code overflow...". This applied to any character class
2424     that was followed by a possessive quantifier.
2426     15. Modified the Makefile to add libpcre.la as a prerequisite for
2427     libpcreposix.la because I was told this is needed for a parallel build to
2428     work.
2430     16. If a pattern that contained .* following optional items at the start was
2431     studied, the wrong optimizing data was generated, leading to matching
2432     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2433     matching string must start with a or b or c. The correct conclusion for
2434     this pattern is that a match can start with any character.
2437 nigel 71 Version 4.4 13-Aug-03
2438     ---------------------
2440     1. In UTF-8 mode, a character class containing characters with values between
2441     127 and 255 was not handled correctly if the compiled pattern was studied.
2442     In fixing this, I have also improved the studying algorithm for such
2443     classes (slightly).
2445     2. Three internal functions had redundant arguments passed to them. Removal
2446     might give a very teeny performance improvement.
2448     3. Documentation bug: the value of the capture_top field in a callout is *one
2449     more than* the number of the hightest numbered captured substring.
2451     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2452     in incorrectly linking with a previously installed version. They now link
2453     explicitly with libpcre.la.
2455     5. configure.in no longer needs to recognize Cygwin specially.
2457     6. A problem in pcre.in for Windows platforms is fixed.
2459     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2460     pcretest, it used to include the size of the study block as part of its
2461     output. Unfortunately, the structure contains a field that has a different
2462     size on different hardware architectures. This meant that the tests that
2463     showed this size failed. As the block is currently always of a fixed size,
2464     this information isn't actually particularly useful in pcretest output, so
2465     I have just removed it.
2467     8. Three pre-processor statements accidentally did not start in column 1.
2468     Sadly, there are *still* compilers around that complain, even though
2469     standard C has not required this for well over a decade. Sigh.
2471     9. In pcretest, the code for checking callouts passed small integers in the
2472     callout_data field, which is a void * field. However, some picky compilers
2473     complained about the casts involved for this on 64-bit systems. Now
2474     pcretest passes the address of the small integer instead, which should get
2475     rid of the warnings.
2477     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2478     both compile and run time, and gives an error if an invalid UTF-8 sequence
2479     is found. There is a option for disabling this check in cases where the
2480     string is known to be correct and/or the maximum performance is wanted.
2482     11. In response to a bug report, I changed one line in Makefile.in from
2484     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2485     to
2486     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2488     to look similar to other lines, but I have no way of telling whether this
2489     is the right thing to do, as I do not use Windows. No doubt I'll get told
2490     if it's wrong...
2493 nigel 69 Version 4.3 21-May-03
2494     ---------------------
2496     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2497     Makefile.
2499     2. Some refactoring to improve the quality of the code:
2501     (i) The utf8_table... variables are now declared "const".
2503     (ii) The code for \cx, which used the "case flipping" table to upper case
2504     lower case letters, now just substracts 32. This is ASCII-specific,
2505     but the whole concept of \cx is ASCII-specific, so it seems
2506     reasonable.
2508     (iii) PCRE was using its character types table to recognize decimal and
2509     hexadecimal digits in the pattern. This is silly, because it handles
2510     only 0-9, a-f, and A-F, but the character types table is locale-
2511     specific, which means strange things might happen. A private
2512     table is now used for this - though it costs 256 bytes, a table is
2513     much faster than multiple explicit tests. Of course, the standard
2514     character types table is still used for matching digits in subject
2515     strings against \d.
2517     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2518     ending in _t are). So I've renamed it as ESC_tee.
2520     3. The first argument for regexec() in the POSIX wrapper should have been
2521     defined as "const".
2523     4. Changed pcretest to use malloc() for its buffers so that they can be
2524     Electric Fenced for debugging.
2526     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2527     to read one or more bytes before the start of the subject string. Often this
2528     had no effect on PCRE's behaviour, but in some circumstances it could
2529     provoke a segmentation fault.
2531     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2532     to try to read one or more bytes before the start of the subject string.
2534     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2535     UTF-8 support could misbehave in various ways if the subject string
2536     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2537     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2538     back over UTF-8 characters.)
2541 nigel 67 Version 4.2 14-Apr-03
2542     ---------------------
2544     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2546     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2547     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2548     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2549     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2550     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2551     and BUILD_EXEEXT
2552     Note: automatic setting of the BUILD variables is not yet working
2553     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2554     compile-time but not at link-time
2555     [LINK]: use for linking executables only
2556     make different versions for Windows and non-Windows
2557     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2558     libraries
2559     [LINK_FOR_BUILD]: new variable
2560     [OBJEXT]: use throughout
2561     [EXEEXT]: use throughout
2562     <winshared>: new target
2563     <wininstall>: new target
2564     <dftables.o>: use native compiler
2565     <dftables>: use native linker
2566     <install>: handle Windows platform correctly
2567     <clean>: ditto
2568     <check>: ditto
2569     copy DLL to top builddir before testing
2571     As part of these changes, -no-undefined was removed again. This was reported
2572     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2573     in any case.
2575     3. Some tidies to get rid of compiler warnings:
2577     . In the match_data structure, match_limit was an unsigned long int, whereas
2578     match_call_count was an int. I've made them both unsigned long ints.
2580     . In pcretest the fact that a const uschar * doesn't automatically cast to
2581     a void * provoked a warning.
2583     . Turning on some more compiler warnings threw up some "shadow" variables
2584     and a few more missing casts.
2586     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2587     option, a class that contained a single character with a value between 128
2588     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2590     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2591     option, a class that contained several characters, but with at least one
2592     whose value was between 128 and 255 caused PCRE to crash.
2595 nigel 65 Version 4.1 12-Mar-03
2596     ---------------------
2597 nigel 63
2598 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2599     needed, and a string in dftables.c that was longer than standard compilers are
2600     required to support.
2602     2. Compiling with Sun's compiler found a few more places where the code could
2603     be tidied up in order to avoid warnings.
2605     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2606     first of these names is deprecated in the latest Autoconf in favour of the name
2607     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2608     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2609     analogy I have changed it to CFLAGS_FOR_BUILD.
2611     4. Added -no-undefined to the linking command in the Makefile, because this is
2612     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2613     linking step for the pcreposix library.
2615     5. PCRE was failing to diagnose the case of two named groups with the same
2616     name.
2618     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2619     literal character that is needed in the subject for a match, and scans along to
2620     ensure that it is present before embarking on the full matching process. This
2621     saves time in cases of nested unlimited repeats that are never going to match.
2622     Problem: the scan can take a lot of time if the subject is very long (e.g.
2623     megabytes), thus penalizing straightforward matches. It is now done only if the
2624     amount of subject to be scanned is less than 1000 bytes.
2626     7. A lesser problem with the same optimization is that it was recording the
2627     first character of an anchored pattern as "needed", thus provoking a search
2628     right along the subject, even when the first match of the pattern was going to
2629     fail. The "needed" character is now not set for anchored patterns, unless it
2630     follows something in the pattern that is of non-fixed length. Thus, it still
2631     fulfils its original purpose of finding quick non-matches in cases of nested
2632     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2635     Version 4.0 17-Feb-03
2636     ---------------------
2638 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2639     extended to the end of string, PCRE compiled incorrect data. This could lead to
2640     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2642     2. Moved to autoconf 2.53 and libtool 1.4.2.
2644     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2645     the special perltest8 script is no longer needed - all the tests can be run
2646     from a single perltest script.
2648     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2649     by \s. It has now been removed in PCRE. This means it isn't recognized as
2650     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2651     class [:space:] *does* include VT, thereby creating a mess.
2653     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2654     space and tab.
2656     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2657     its new features into the main test script, reducing the number of scripts.
2659     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2660     were backward compatible, and made the (?i) apply to the whole pattern, as if
2661     /i were given. Now it behaves more logically, and applies the option setting
2662     only to what follows. PCRE has been changed to follow suit. However, if it
2663     finds options settings right at the start of the pattern, it extracts them into
2664     the global options, as before. Thus, they show up in the info data.
2666     8. Added support for the \Q...\E escape sequence. Characters in between are
2667     treated as literals. This is slightly different from Perl in that $ and @ are
2668     also handled as literals inside the quotes. In Perl, they will cause variable
2669     interpolation. Note the following examples:
2671     Pattern PCRE matches Perl matches
2673     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2674     \Qabc\$xyz\E abc\$xyz abc\$xyz
2675     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2677     For compatibility with Perl, \Q...\E sequences are recognized inside character
2678     classes as well as outside them.
2680     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2681     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2682     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2683     signed/unsigned warnings.
2685     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2686     option for pcretest, so I've replaced it by a simple function that does just
2687     that job.
2689     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2690     "pcregrep -".
2692     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2693     Java package. This provides some syntactic sugar for simple cases of what my
2694     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2695     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2696     item, you can use this simplified notation. Note that only makes sense with
2697     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2698     greediness, whatever the setting of the PCRE_UNGREEDY option.
2700     13. A change of greediness default within a pattern was not taking effect at
2701     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2702     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2703     was abstracted outside.
2705     14. PCRE now supports the \G assertion. It is true when the current matching
2706     position is at the start point of the match. This differs from \A when the
2707     starting offset is non-zero. Used with the /g option of pcretest (or similar
2708     code), it works in the same way as it does for Perl's /g option. If all
2709     alternatives of a regex begin with \G, the expression is anchored to the start
2710     match position, and the "anchored" flag is set in the compiled expression.
2712     15. Some bugs concerning the handling of certain option changes within patterns
2713     have been fixed. These applied to options other than (?ims). For example,
2714     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2715     been the other way round. Some of this was related to change 7 above.
2717     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2718     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2719     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2720     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2722     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2723     mode. Unlike ".", it always matches newline, whatever the setting of
2724     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2725     assertions. Perl allows it, but it doesn't (in general) work because it can't
2726     calculate the length of the lookbehind. At least, that's the case for Perl
2727     5.8.0 - I've been told they are going to document that it doesn't work in
2728     future.
2730     18. Added an error diagnosis for escapes that PCRE does not support: these are
2731     \L, \l, \N, \P, \p, \U, \u, and \X.
2733     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2734     reading past the end of the pattern in cases such as /[abcd/.
2736     20. PCRE was getting more memory than necessary for patterns with classes that
2737     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2739     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2740     compiling PCRE for use with Virtual Pascal.
2742     22. Small fix to the Makefile to make it work properly if the build is done
2743     outside the source tree.
2745     23. Added a new extension: a condition to go with recursion. If a conditional
2746     subpattern starts with (?(R) the "true" branch is used if recursion has
2747     happened, whereas the "false" branch is used only at the top level.
2749     24. When there was a very long string of literal characters (over 255 bytes
2750     without UTF support, over 250 bytes with UTF support), the computation of how
2751     much memory was required could be incorrect, leading to segfaults or other
2752     strange effects.
2754     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2755     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2756     there was a subsequent back reference to those brackets. This meant that, for
2757     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2758     possible to check for precisely this case. All we can do is abandon the
2759     optimization if .* occurs inside capturing brackets when there are any back
2760     references whatsoever. (See below for a better fix that came later.)
2762     26. The handling of the optimization for finding the first character of a
2763     non-anchored pattern, and for finding a character that is required later in the
2764     match were failing in some cases. This didn't break the matching; it just
2765     failed to optimize when it could. The way this is done has been re-implemented.
2767     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2769     28. Added a new feature that provides some of the functionality that Perl
2770     provides with (?{...}). The facility is termed a "callout". The way it is done
2771     in PCRE is for the caller to provide an optional function, by setting
2772     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2773     global variable. By default it is unset, which disables all calling out. To get
2774     the function called, the regex must include (?C) at appropriate points. This
2775     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2776     This provides a means of identifying different callout points. When PCRE
2777     reaches such a point in the regex, if pcre_callout has been set, the external
2778     function is called. It is provided with data in a structure called
2779     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2780     matching continues; if it returns a non-zero value, the match at the current
2781     point fails. However, backtracking will occur if possible. [This was changed
2782     later and other features added - see item 49 below.]
2784     29. pcretest is upgraded to test the callout functionality. It provides a
2785     callout function that displays information. By default, it shows the start of
2786     the match and the current position in the text. There are some new data escapes
2787     to vary what happens:
2789     \C+ in addition, show current contents of captured substrings
2790     \C- do not supply a callout function
2791     \C!n return 1 when callout number n is reached
2792     \C!n!m return 1 when callout number n is reached for the mth time
2794     30. If pcregrep was called with the -l option and just a single file name, it
2795     output "<stdin>" if a match was found, instead of the file name.
2797     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2798     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2799     pcre_exec(). This saves a malloc/free per call. The default value of
2800     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2801     when configuring.
2803     32. The default maximum size of a compiled pattern is 64K. There have been a
2804     few cases of people hitting this limit. The code now uses macros to handle the
2805     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2806     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2807     configuring. Tests 2 and 5 work only with 2-byte links because they output
2808     debugging information about compiled patterns.
2810     33. Internal code re-arrangements:
2812     (a) Moved the debugging function for printing out a compiled regex into
2813     its own source file (printint.c) and used #include to pull it into
2814     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2815     separate copies.
2817     (b) Defined the list of op-code names for debugging as a macro in
2818     internal.h so that it is next to the definition of the opcodes.
2820     (c) Defined a table of op-code lengths for simpler skipping along compiled
2821     code. This is again a macro in internal.h so that it is next to the
2822     definition of the opcodes.
2824     34. Added support for recursive calls to individual subpatterns, along the
2825     lines of Robin Houston's patch (but implemented somewhat differently).
2827     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2828     allow it to read and process whole directories in Win32. This code was
2829     contributed by Lionel Fourquaux; it has not been tested by me.
2831     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2832     used to name a group. Names consist of alphanumerics and underscores, and must
2833     be unique. Back references use the syntax (?P=name) and recursive calls use
2834     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2835     numbers. The function pcre_fullinfo() can be used after compilation to extract
2836     a name/number map. There are three relevant calls:
2838     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2839     PCRE_INFO_NAMECOUNT yields the number of entries
2840     PCRE_INFO_NAMETABLE yields a pointer to the map.
2842     The map is a vector of fixed-size entries. The size of each entry depends on
2843     the length of the longest name used. The first two bytes of each entry are the
2844     group number, most significant byte first. There follows the corresponding
2845     name, zero terminated. The names are in alphabetical order.
2847     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2848     case instead of 255. Making it the same both with and without UTF-8 support
2849     means that the same test output works with both.
2851     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2852     calling malloc() with a zero argument.
2854     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2855     optimization. I've improved things by keeping a bitmap of backreferences with
2856     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2857     fact referenced, the optimization can be applied. It is unlikely that a
2858     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2859     the match to follow \n) will appear inside brackets with a number greater than
2860     31, but if it does, any back reference > 31 suppresses the optimization.
2862     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2863     of disabling numbered capturing parentheses. Any opening parenthesis that is
2864     not followed by ? behaves as if it were followed by ?: but named parentheses
2865     can still be used for capturing (and they will acquire numbers in the usual
2866     way).
2868     41. Redesigned the return codes from the match() function into yes/no/error so
2869     that errors can be passed back from deep inside the nested calls. A malloc
2870     failure while inside a recursive subpattern call now causes the
2871     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2873     42. It is now possible to set a limit on the number of times the match()
2874     function is called in a call to pcre_exec(). This facility makes it possible to
2875     limit the amount of recursion and backtracking, though not in a directly
2876     obvious way, because the match() function is used in a number of different
2877     circumstances. The count starts from zero for each position in the subject
2878     string (for non-anchored patterns). The default limit is, for compatibility, a
2879     large number, namely 10 000 000. You can change this in two ways:
2881     (a) When configuring PCRE before making, you can use --with-match-limit=n
2882     to set a default value for the compiled library.
2884     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2885     a different value is set. See 45 below.
2887     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2889     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2890     of things that can be changed at compile time. The first argument specifies
2891     what is wanted and the second points to where the information is to be placed.
2892     The current list of available information is:
2896     The output is an integer that is set to one if UTF-8 support is available;
2897     otherwise it is set to zero.
2901     The output is an integer that it set to the value of the code that is used for
2902     newline. It is either LF (10) or CR (13).
2906     The output is an integer that contains the number of bytes used for internal
2907     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2911     The output is an integer that contains the threshold above which the POSIX
2912     interface uses malloc() for output vectors. See item 31 above.
2916     The output is an unsigned integer that contains the default limit of the number
2917     of match() calls in a pcre_exec() execution. See 42 above.
2919     44. pcretest has been upgraded by the addition of the -C option. This causes it
2920     to extract all the available output from the new pcre_config() function, and to
2921     output it. The program then exits immediately.
2923     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2924     order to support additional features. One way would have been to define
2925     pcre_exec2() (for example) with extra arguments, but this would not have been
2926     extensible, and would also have required all calls to the original function to
2927     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2928     is used for passing in "extra" data from pcre_study().
2930     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2931     contains the following fields:
2933     flags a bitmap indicating which of the following fields are set
2934     study_data opaque data from pcre_study()
2935     match_limit a way of specifying a limit on match() calls for a specific
2936     call to pcre_exec()
2937     callout_data data for callouts (see 49 below)
2939     The flag bits are also defined in pcre.h, and are
2945     The pcre_study() function now returns one of these new pcre_extra blocks, with
2946     the actual study data pointed to by the study_data field, and the
2947     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2948     before. That is, this change is entirely upwards-compatible and requires no
2949     change to existing code.
2951     If you want to pass in additional data to pcre_exec(), you can either place it
2952     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2953     block.
2955     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2956     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2957     times with different match limits, until it finds the minimum value needed for
2958     pcre_exec() to complete. The value is then output. This can be instructive; for
2959     most simple matches the number is quite small, but for pathological cases it
2960     gets very large very quickly.
2962     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2963     returns the size of the data block pointed to by the study_data field in a
2964     pcre_extra block, that is, the value that was passed as the argument to
2965     pcre_malloc() when PCRE was getting memory in which to place the information
2966     created by pcre_study(). The fourth argument should point to a size_t variable.
2967     pcretest has been extended so that this information is shown after a successful
2968     pcre_study() call when information about the compiled regex is being displayed.
2970     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2971     because what follows is always an absolute path. (Later: it turns out that this
2972     is more than cosmetic for MinGW, because it doesn't like empty path
2973     components.)
2975     49. Some changes have been made to the callout feature (see 28 above):
2977     (i) A callout function now has three choices for what it returns:
2979     0 => success, carry on matching
2980     > 0 => failure at this point, but backtrack if possible
2981     < 0 => serious error, return this value from pcre_exec()
2983     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2984     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2985     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2986     use by callout functions. It will never be used by PCRE itself.
2988     (ii) The pcre_extra structure (see 45 above) has a void * field called
2989     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2990     pcre_callout_block structure has a field of the same name. The contents of
2991     the field passed in the pcre_extra structure are passed to the callout
2992     function in the corresponding field in the callout block. This makes it
2993     easier to use the same callout-containing regex from multiple threads. For
2994     testing, the pcretest program has a new data escape
2996     \C*n pass the number n (may be negative) as callout_data
2998     If the callout function in pcretest receives a non-zero value as
2999     callout_data, it returns that value.
3001     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3002     there were some redundant $(CFLAGS) in commands that are now specified as
3003     $(LINK), which already includes $(CFLAGS).
3005     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3006     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3007     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3008     one-byte characters throughout. Note that case-insensitive matching applies
3009     only to characters whose values are less than 256. PCRE doesn't support the
3010     notion of cases for higher-valued characters.
3012     (i) A character class whose characters are all within 0-255 is handled as
3013     a bit map, and the map is inverted for negative classes. Previously, a
3014     character > 255 always failed to match such a class; however it should
3015     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3017     (ii) A negated character class with a single character < 255 is coded as
3018     "not this character" (OP_NOT). This wasn't working properly when the test
3019     character was multibyte, either singly or repeated.
3021     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3022     mode, for example: \x{100}{2,3}.
3024     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3025     singly or repeated) now correctly test multibyte characters. However,
3026     PCRE doesn't recognize any characters with values greater than 255 as
3027     digits, spaces, or word characters. Such characters always match \D, \S,
3028     and \W, and never match \d, \s, or \w.
3030     (v) Classes may now contain characters and character ranges with values
3031     greater than 255. For example: [ab\x{100}-\x{400}].
3033     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3034     PCRE in UTF-8 mode.
3036     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3037     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3038     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3039     value.)
3041     53. The single man page has become too large. I have therefore split it up into
3042     a number of separate man pages. These also give rise to individual HTML pages;
3043     these are now put in a separate directory, and there is an index.html page that
3044     lists them all. Some hyperlinking between the pages has been installed.
3046     54. Added convenience functions for handling named capturing parentheses.
3048     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3049     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3050     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3051     are faulted.
3053     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3054     calling configure. These values are used when compiling the dftables.c program
3055     which is run to generate the source of the default character tables. They
3056     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3057     you will need to set these values.
3059     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3062     Version 3.9 02-Jan-02
3063 nigel 61 ---------------------
3065     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3067     2. If --disable-static was given, the building process failed when trying to
3068     build pcretest and pcregrep. (For some reason it was using libtool to compile
3069     them, which is not right, as they aren't part of the library.)
3072 nigel 59 Version 3.8 18-Dec-01
3073     ---------------------
3075     1. The experimental UTF-8 code was completely screwed up. It was packing the
3076     bytes in the wrong order. How dumb can you get?
3079 nigel 57 Version 3.7 29-Oct-01
3080     ---------------------
3082     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3083     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3084     this didn't happen under Solaris 8, where I normally test things.
3086 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3087     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3088     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3089     this fix an hour or so after the initial 3.7 release.)
3090 nigel 57
3091 nigel 59
3092 nigel 55 Version 3.6 23-Oct-01
3093     ---------------------
3095     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3096     offsets passed as NULL with zero offset count.
3098     2. The config.guess and config.sub files had not been updated when I moved to
3099     the latest autoconf.
3102 nigel 53 Version 3.5 15-Aug-01
3103     ---------------------
3104 nigel 5
3105 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3106     had been forgotten.
3108     2. By using declared but undefined structures, we can avoid using "void"
3109     definitions in pcre.h while keeping the internal definitions of the structures
3110     private.
3112     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3113     user point of view, this means that both static and shared libraries are built
3114     by default, but this can be individually controlled. More of the work of
3115     handling this static/shared cases is now inside libtool instead of PCRE's make
3116     file.
3118     4. The pcretest utility is now installed along with pcregrep because it is
3119     useful for users (to test regexs) and by doing this, it automatically gets
3120     relinked by libtool. The documentation has been turned into a man page, so
3121     there are now .1, .txt, and .html versions in /doc.
3123     5. Upgrades to pcregrep:
3124     (i) Added long-form option names like gnu grep.
3125     (ii) Added --help to list all options with an explanatory phrase.
3126     (iii) Added -r, --recursive to recurse into sub-directories.
3127     (iv) Added -f, --file to read patterns from a file.
3129     6. pcre_exec() was referring to its "code" argument before testing that
3130     argument for NULL (and giving an error if it was NULL).
3132     7. Upgraded Makefile.in to allow for compiling in a different directory from
3133     the source directory.
3135     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3136     options bits, the pointer it was passed was to an int instead of to an unsigned
3137     long int. This mattered only on 64-bit systems.
3139     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3140     generated) instead of pcre.in, which it its source. Also made the same change
3141     in several of the .c files.
3143     10. A new release of gcc defines printf() as a macro, which broke pcretest
3144     because it had an ifdef in the middle of a string argument for printf(). Fixed
3145     by using separate calls to printf().
3147     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3148     script, to force use of CR or LF instead of \n in the source. On non-Unix
3149     systems, the value can be set in config.h.
3151     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3152     absolute limit. Changed the text of the error message to make this clear, and
3153     likewise updated the man page.
3155     13. The limit of 99 on the number of capturing subpatterns has been removed.
3156     The new limit is 65535, which I hope will not be a "real" limit.
3159 nigel 51 Version 3.4 22-Aug-00
3160     ---------------------
3162     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3164     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3167 nigel 49 Version 3.3 01-Aug-00
3168     ---------------------
3170     1. If an octal character was given, but the value was greater than \377, it
3171     was not getting masked to the least significant bits, as documented. This could
3172     lead to crashes in some systems.
3174     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3175     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3177     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3178     These just pass their arguments on to (pcre_free)(), but they are provided
3179     because some uses of PCRE bind it to non-C systems that can call its functions,
3180     but cannot call free() or pcre_free() directly.
3182     4. Add "make test" as a synonym for "make check". Corrected some comments in
3183     the Makefile.
3185     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3186     Makefile.
3188     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3189     command called pgrep for grepping around the active processes.
3191     7. Added the beginnings of support for UTF-8 character strings.
3193     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3194     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3195     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3196     out for the ar command.)
3199 nigel 47 Version 3.2 12-May-00
3200     ---------------------
3202     This is purely a bug fixing release.
3204     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3205     of ZA. This was just one example of several cases that could provoke this bug,
3206     which was introduced by change 9 of version 2.00. The code for breaking
3207     infinite loops after an iteration that matches an empty string was't working
3208     correctly.
3210     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3211     when matched against abbab (for example). After matching an empty string, it
3212     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3213     caused it to match further down the string than it should.
3215     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3216     was there because it doesn't seem to be needed, and it causes trouble on some
3217     systems, as it is not a Standard C header. It has been removed.
3219     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3220     were reported on the Macintosh. The changes were from
3222     while ((c = *(++ptr)) != 0 && c != '\n');
3223     to
3224     while ((c = *(++ptr)) != 0 && c != '\n') ;
3226     Totally extraordinary, but if that's what it takes...
3228     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3229     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3230     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3231     assumes the way PCRE uses memmove() (always moving upwards).
3233     6. PCRE is being used in one environment where strchr() is not available. There
3234     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3235     faster code anyway.
3238 nigel 45 Version 3.1 09-Feb-00
3239     ---------------------
3241     The only change in this release is the fixing of some bugs in Makefile.in for
3242     the "install" target:
3244     (1) It was failing to install pcreposix.h.
3246     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3249 nigel 43 Version 3.0 01-Feb-00
3250     ---------------------
3251 nigel 41
3252     1. Add support for the /+ modifier to perltest (to output $` like it does in
3253     pcretest).
3255     2. Add support for the /g modifier to perltest.
3257     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3258     matches null strings.
3260     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3261     pattern. Perl treats empty patterns specially - it reuses the most recent
3262     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3263     effect.
3265     5. The POSIX interface was broken in that it was just handing over the POSIX
3266     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3267     required a bigger vector, with some working space on the end. This means that
3268     the POSIX wrapper now has to get and free some memory, and copy the results.
3270 nigel 43 6. Added some simple autoconf support, placing the test data and the
3271     documentation in separate directories, re-organizing some of the
3272     information files, and making it build pcre-config (a GNU standard). Also added
3273     libtool support for building PCRE as a shared library, which is now the
3274     default.
3275 nigel 41
3276 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3277     09 are not valid octal constants. Single digits will be used for minor values
3278     less than 10.
3280     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3281     existing programs that set these in the POSIX interface can use PCRE without
3282     modification.
3284     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3285     return all that pcre_info() returns, plus additional data. The pcre_info()
3286     function is retained for compatibility, but is considered to be obsolete.
3288     10. Added experimental recursion feature (?R) to handle one common case that
3289     Perl 5.6 will be able to do with (?p{...}).
3291     11. Added support for POSIX character classes like [:alpha:], which Perl is
3292     adopting.
3295 nigel 39 Version 2.08 31-Aug-99
3296     ----------------------
3298     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3299     trying to match at the startoffset position, but instead was moving forward to
3300     the next newline as if a previous match had failed.
3302     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3303     and could get into a loop if a null string was matched other than at the start
3304     of the subject.
3306     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3307     be distinguished at compile time, and for completeness also added PCRE_DATE.
3309     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3310     in GnuWin32 environments.
3313 nigel 37 Version 2.07 29-Jul-99
3314     ----------------------
3316     1. The documentation is now supplied in plain text form and HTML as well as in
3317     the form of man page sources.
3319     2. C++ compilers don't like assigning (void *) values to other pointer types.
3320     In particular this affects malloc(). Although there is no problem in Standard
3321     C, I've put in casts to keep C++ compilers happy.
3323     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3324     should be (const char *).
3326     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3327     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3328     However, I haven't made this a standard facility. The documentation doesn't
3329     mention it, and the Makefile doesn't support it.
3331     5. The Makefile now contains an "install" target, with editable destinations at
3332     the top of the file. The pcretest program is not installed.
3334     6. pgrep -V now gives the PCRE version number and date.
3336     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3337     causing the entire string to be ignored, instead of just the last character.
3339     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3340     non-matching string, it can take a very, very long time, even for strings of
3341     quite modest length, because of the nested recursion. PCRE now does better in
3342     some of these cases. It does this by remembering the last required literal
3343     character in the pattern, and pre-searching the subject to ensure it is present
3344     before running the real match. In other words, it applies a heuristic to detect
3345     some types of certain failure quickly, and in the above example, if presented
3346     with a string that has no trailing " it gives "no match" very quickly.
3348     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3349     other alternatives are tried instead.
3352 nigel 35 Version 2.06 09-Jun-99
3353     ----------------------
3355     1. Change pcretest's output for amount of store used to show just the code
3356     space, because the remainder (the data block) varies in size between 32-bit and
3357     64-bit systems.
3359     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3360     start matching at. This allows lookbehinds to work when searching for multiple
3361     occurrences in a string.
3363     3. Added additional options to pcretest for testing multiple occurrences:
3365     /+ outputs the rest of the string that follows a match
3366     /g loops for multiple occurrences, using the new startoffset argument
3367     /G loops for multiple occurrences by passing an incremented pointer
3369     4. PCRE wasn't doing the "first character" optimization for patterns starting
3370     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3371     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3372     the letter 'x'. On long subject strings, this gives a significant speed-up.
3375 nigel 33 Version 2.05 21-Apr-99
3376     ----------------------
3378     1. Changed the type of magic_number from int to long int so that it works
3379     properly on 16-bit systems.
3381     2. Fixed a bug which caused patterns starting with .* not to work correctly
3382     when the subject string contained newline characters. PCRE was assuming
3383     anchoring for such patterns in all cases, which is not correct because .* will
3384     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3385     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3386     must be retried after every newline in the subject.
3389 nigel 31 Version 2.04 18-Feb-99
3390     ----------------------
3392     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3393     computation of the store needed to hold the pattern was incorrect (too large).
3394     If such patterns were nested a few deep, this could multiply and become a real
3395     problem.
3397     2. Added /M option to pcretest to show the memory requirement of a specific
3398     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3400     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3401     compiled in such a way that the backtracking after subsequent failure was
3402     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3403     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3406 nigel 29 Version 2.03 02-Feb-99
3407     ----------------------
3409     1. Fixed typo and small mistake in man page.
3411 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3412     LICENCE file containing the conditions.
3413 nigel 29
3414     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3415     Perl, that is the internal \ allows the delimiter to be included in the
3416     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3417     the final delimiter, add \ to the end of the pattern (to test the error).
3419     4. Added the convenience functions for extracting substrings after a successful
3420     match. Updated pcretest to make it able to test these functions.
3423 nigel 27 Version 2.02 14-Jan-99
3424     ----------------------
3426     1. Initialized the working variables associated with each extraction so that
3427     their saving and restoring doesn't refer to uninitialized store.
3429     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3430     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3431     fix the problem.
3433     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3434     calls, and wasn't printing the correct value for compiling calls. Increased the
3435     default value of LOOPREPEAT, and the number of significant figures in the
3436     times.
3438     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3440     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3441     a building problem on Windows NT with a FAT file system.
3444 nigel 25 Version 2.01 21-Oct-98
3445     ----------------------
3447     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3448     to character tables built by pcre_maketables() in the current locale. If NULL
3449     is passed, the default tables are used.
3452 nigel 23 Version 2.00 24-Sep-98
3453 nigel 21 ----------------------
3455 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3456     it any more.
3458     2. Allow quantification of (?>) groups, and make it work correctly.
3460     3. The first character computation wasn't working for (?>) groups.
3462     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3463     end of the subject) and add 5.005's \z, which really does match only at the
3464     very end of the subject.
3466     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3468     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3469     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3470     localized options. All options to pcre_study() were also removed.
3472     7. Add other new features from 5.005:
3474     $(?<= positive lookbehind
3475     $(?<! negative lookbehind
3476     (?imsx-imsx) added the unsetting capability
3477     such a setting is global if at outer level; local otherwise
3478     (?imsx-imsx:) non-capturing groups with option setting
3479     (?(cond)re|re) conditional pattern matching
3481     A backreference to itself in a repeated group matches the previous
3482     captured string.
3484     8. General tidying up of studying (both automatic and via "study")
3485     consequential on the addition of new assertions.
3487     9. As in 5.005, unlimited repeated groups that could match an empty substring
3488     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3489     runtime if any iteration does actually match an empty substring.
3491     10. Include the RunTest script in the distribution.
3493     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3494     discrepancies, some of which were old and were also with respect to 5.004. They
3495     have now been fixed.
3498     Version 1.09 28-Apr-98
3499     ----------------------
3501 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3502     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3503     program crashes, or just wrong answers. This did not apply to negated classes
3504     containing more than one character, or to minima other than one.
3507 nigel 19 Version 1.08 27-Mar-98
3508     ----------------------
3510     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3512     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3513     latter must appear before anything that relies on it in the pattern.
3516 nigel 17 Version 1.07 16-Feb-98
3517     ----------------------
3519     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3520     repeat of a potentially empty string).
3523 nigel 15 Version 1.06 23-Jan-98
3524     ----------------------
3526     1. Added Markus Oberhumer's little patches for C++.
3528     2. Literal strings longer than 255 characters were broken.
3531 nigel 13 Version 1.05 23-Dec-97
3532     ----------------------
3534     1. Negated character classes containing more than one character were failing if
3535     PCRE_CASELESS was set at run time.
3538 nigel 11 Version 1.04 19-Dec-97
3539     ----------------------
3541     1. Corrected the man page, where some "const" qualifiers had been omitted.
3543     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3544     input syntax.
3546     3. Fixed memory leak which occurred when a regex with back references was
3547     matched with an offsets vector that wasn't big enough. The temporary memory
3548     that is used in this case wasn't being freed if the match failed.
3550     4. Tidied pcretest to ensure it frees memory that it gets.
3552     5. Temporary memory was being obtained in the case where the passed offsets
3553     vector was exactly big enough.
3555     6. Corrected definition of offsetof() from change 5 below.
3557     7. I had screwed up change 6 below and broken the rules for the use of
3558     setjmp(). Now fixed.
3561 nigel 9 Version 1.03 18-Dec-97
3562     ----------------------
3564     1. A erroneous regex with a missing opening parenthesis was correctly
3565     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3566     on some systems.
3568     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3569     it was reported that one broken compiler failed on the former because "code" is
3570     also an independent variable.
3572     3. The erroneous regex a[]b caused an array overrun reference.
3574     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3575     fail on data ending with that character. (It was going on too far, and checking
3576     the next character, typically a binary zero.) This was specific to the
3577     optimized code for single-character negative classes.
3579     5. Added a contributed patch from the TIN world which does the following:
3581     + Add an undef for memmove, in case the the system defines a macro for it.
3583     + Add a definition of offsetof(), in case there isn't one. (I don't know
3584     the reason behind this - offsetof() is part of the ANSI standard - but
3585     it does no harm).
3587     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3588     most of the places where whitespace preceded '#'. I have given up and
3589     allowed the remaining 2 cases to be at the margin.
3591     + Rename some variables in pcre to eliminate shadowing. This seems very
3592     pedantic, but does no harm, of course.
3594     6. Moved the call to setjmp() into its own function, to get rid of warnings
3595     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3597     7. Constructs such as \d{8,} were compiling into the equivalent of
3598 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3599 nigel 9 outcome, but in this particular case used more store than had been allocated,
3600     which caused the bug to be discovered because it threw up an internal error.
3602     8. The debugging code in both pcre and pcretest for outputting the compiled
3603     form of a regex was going wrong in the case of back references followed by
3604     curly-bracketed repeats.
3607 nigel 7 Version 1.02 12-Dec-97
3608     ----------------------
3610     1. Typos in pcre.3 and comments in the source fixed.
3612     2. Applied a contributed patch to get rid of places where it used to remove
3613     'const' from variables, and fixed some signed/unsigned and uninitialized
3614     variable warnings.
3616     3. Added the "runtest" target to Makefile.
3618     4. Set default compiler flag to -O2 rather than just -O.
3621 nigel 5 Version 1.01 19-Nov-97
3622     ----------------------
3624     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3625     like /([ab]*)*/, that is, for classes with more than one character in them.
3627     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3628     as /((?>a*))*/ (a PCRE_EXTRA facility).
3631     Version 1.00 18-Nov-97
3632     ----------------------
3634     1. Added compile-time macros to support systems such as SunOS4 which don't have
3635     memmove() or strerror() but have other things that can be used instead.
3637     2. Arranged that "make clean" removes the executables.
3640 nigel 3 Version 0.99 27-Oct-97
3641     ----------------------
3643     1. Fixed bug in code for optimizing classes with only one character. It was
3644     initializing a 32-byte map regardless, which could cause it to run off the end
3645     of the memory it had got.
3647     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3650     Version 0.98 22-Oct-97
3651     ----------------------
3653     1. Fixed bug in code for handling temporary memory usage when there are more
3654     back references than supplied space in the ovector. This could cause segfaults.
3657     Version 0.97 21-Oct-97
3658     ----------------------
3660     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3662     2. Optimized negated single characters not to use a bit map.
3664     3. Brought error texts together as macro definitions; clarified some of them;
3665     fixed one that was wrong - it said "range out of order" when it meant "invalid
3666     escape sequence".
3668     4. Changed some char * arguments to const char *.
3670     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3672     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3673     pcretest.
3676     Version 0.96 16-Oct-97
3677     ----------------------
3679     1. Added a simple "pgrep" utility to the distribution.
3681     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3682     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3683     where "ddd" means "one or more decimal digits".
3685     3. Fixed serious bug. If a pattern had a back reference, but the call to
3686     pcre_exec() didn't supply a large enough ovector to record the related
3687     identifying subpattern, the match always failed. PCRE now remembers the number
3688     of the largest back reference, and gets some temporary memory in which to save
3689     the offsets during matching if necessary, in order to ensure that
3690     backreferences always work.
3692     4. Increased the compatibility with Perl in a number of ways:
3694     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3695     to request this handling. The option can be set at compile or exec time.
3697     (b) $ matches before a terminating newline by default; an option
3698     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3699     mode). The option can be set at compile or exec time.
3701     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3702     the same as Perl's. If the decimal number it represents is less than 10
3703     or there aren't that many previous left capturing parentheses, an octal
3704     escape is read. Inside a character class, it's always an octal escape,
3705     even if it is a single digit.
3707     (d) An escaped but undefined alphabetic character is taken as a literal,
3708     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3709     escapes.
3711     (e) {0} is now permitted. (The previous item is removed from the compiled
3712     pattern).
3714     5. Changed all the names of code files so that the basic parts are no longer
3715     than 10 characters, and abolished the teeny "globals.c" file.
3717     6. Changed the handling of character classes; they are now done with a 32-byte
3718     bit map always.
3720     7. Added the -d and /D options to pcretest to make it possible to look at the
3721     internals of compilation without having to recompile pcre.
3724     Version 0.95 23-Sep-97
3725     ----------------------
3727     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3728     \x20 at the start of a run of normal characters. These were being treated as
3729     real characters, instead of the source characters being re-checked.
3732     Version 0.94 18-Sep-97
3733     ----------------------
3735     1. The functions are now thread-safe, with the caveat that the global variables
3736     containing pointers to malloc() and free() or alternative functions are the
3737     same for all threads.
3739     2. Get pcre_study() to generate a bitmap of initial characters for non-
3740     anchored patterns when this is possible, and use it if passed to pcre_exec().
3743     Version 0.93 15-Sep-97
3744     ----------------------
3746     1. /(b)|(:+)/ was computing an incorrect first character.
3748     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3749     but not actually doing anything yet.
3751     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3752     as Perl does (e.g. [-az] or [az-]).
3754     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3755     all possible positions.
3757     5. Split up into different modules to avoid including unneeded functions in a
3758     compiled binary. However, compile and exec are still in one module. The "study"
3759     function is split off.
3761     6. The character tables are now in a separate module whose source is generated
3762     by an auxiliary program - but can then be edited by hand if required. There are
3763     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3764     toupper() in the code.
3766     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3767     make them global. Abolish the function for setting them, as the caller can now
3768     set them directly.
3771     Version 0.92 11-Sep-97
3772     ----------------------
3774     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3775     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3777     2. Caseless matching was not working in character classes if the characters in
3778     the pattern were in upper case.
3780     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3782     4. Make PCRE_ANCHORED public and accept as a compile option.
3784     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3785     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3786     pass them.
3788     6. Give an error if bad option bits passed at compile or run time.
3790     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3791     pcretest to cause it to pass that flag.
3793     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3794     options, and the first character, if set.
3796     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3799     Version 0.91 10-Sep-97
3800     ----------------------
3802     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3803     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3805     2. PCRE was looping on encountering an indefinitely repeated back reference to
3806     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3807     Perl does - treats the match as successful.
3809     ****


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