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Revision 489 - (hide annotations) (download)
Tue Jan 19 16:42:21 2010 UTC (5 years, 2 months ago) by ph10
File size: 181540 byte(s)
File tidies and documentation update for 8.01.

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