ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log

Revision 538 - (hide annotations) (download)
Wed Jun 9 19:30:57 2010 UTC (4 years, 9 months ago) by ph10
File size: 189009 byte(s)
Fix pcre_study() problem with non-C-locale chartables in UTF-8 mode.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 535 Version 8.10 03-Jun-2010
5 ph10 510 ------------------------
7 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8 ph10 510 THEN.
10 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
11 ph10 510
12 ph10 535 3. Inside a character class, \B is treated as a literal by default, but
13     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
15 ph10 535
16     4. Inside a character class, PCRE always treated \R and \X as literals,
17 ph10 513 whereas Perl faults them if its -w option is set. I have changed PCRE so
18     that it faults them when PCRE_EXTRA is set.
19 ph10 535
20 ph10 514 5. Added support for \N, which always matches any character other than
21     newline. (It is the same as "." when PCRE_DOTALL is not set.)
22 ph10 535
23 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
24 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
26 ph10 535 result to (void) does not stop the warnings; a more elaborate fudge is
27     needed. I've used a macro to implement this.
28 ph10 512
29 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
31 ph10 517 8. Added four artifical Unicode properties to help with an option to make
32 ph10 518 \s etc use properties (see next item). The new properties are: Xan
33     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
34 ph10 535
35 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
37 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
38     REG_UCP to make it available via the POSIX interface.
39 ph10 513
40 ph10 535 10. Added --line-buffered to pcregrep.
42     11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43     studied, and the match started with a letter with a code point greater than
44 ph10 520 127 whose first byte was different to the first byte of the other case of
45 ph10 536 the letter, the other case of this starting letter was not recognized
46     (#976).
47 ph10 535
48 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
49 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
50 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
51     not have actually happened in practice until change 8 above was made (it
52 ph10 523 added property types that matched character-matching opcodes).
53 ph10 535
54 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
55 ph10 535 possible starting bytes for non-anchored patterns.
57 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
58 ph10 535 \R, and also a number of cases that involve Unicode properties, both
59 ph10 532 explicit and implicit when PCRE_UCP is set.
60 ph10 529
61 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
62 ph10 535 input, it could crash or give wrong results if characters with values
63     greater than 0xc0 were present in the subject string. (Detail: it assumed
64 ph10 529 UTF-8 input when processing these items.)
65 ph10 535
66 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
67     size_t is 64-bit (#991).
68 ph10 535
69 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
70     --disable-stack-for-recursion (#990).
72 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
73     the end, a newline was missing in the output.
75 ph10 538 19. The default pcre_chartables.c file recognizes only ASCII characters (values
76     less than 128) in its various bitmaps. However, there is a facility for
77     generating tables according to the current locale when PCRE is compiled. It
78     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
79     characters, are recognized by isspace() and therefore were getting set in
80     these tables. This caused a problem in UTF-8 mode when pcre_study() was
81     used to create a list of bytes that can start a match. For \s, it was
82     including 0x85 and 0xa0, which of course cannot start UTF-8 characters. I
83     have changed the code so that only real ASCII characters (less than 128)
84     are set in this case because the \s etc escapes are documented as
85     recognizing only ASCII characters. (When PCRE_UCP is set - see 9 above -
86     the code is different altogether.)
87 ph10 517
88 ph10 520
89 ph10 508 Version 8.02 19-Mar-2010
90 ph10 491 ------------------------
92     1. The Unicode data tables have been updated to Unicode 5.2.0.
94 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
95     configured.
96 ph10 507
97 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
98 ph10 507 original author of that file, following a query about its status.
100     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
101 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
102 ph10 507
103 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
104     quantifier applied to a forward-referencing subroutine call, could compile
105     incorrect code or give the error "internal error: previously-checked
106     referenced subpattern not found".
107 ph10 507
108     6. Both MS Visual Studio and Symbian OS have problems with initializing
109 ph10 497 variables to point to external functions. For these systems, therefore,
110     pcre_malloc etc. are now initialized to local functions that call the
111     relevant global functions.
112 ph10 507
113 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
114     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
115 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
116     the lengths are correct (equal to the number of opcodes).
118     8. Following on from 7, I added a similar kludge to check the length of the
119     eint vector in pcreposix.c.
121     9. Error texts for pcre_compile() are held as one long string to avoid too
122     much relocation at load time. To find a text, the string is searched,
123 ph10 499 counting zeros. There was no check for running off the end of the string,
124     which could happen if a new error number was added without updating the
125 ph10 507 string.
127     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
129 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
130 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
131     \K is "not well defined" if used in an assertion. PCRE now accepts it if
132     the assertion is positive, but not if it is negative.
134 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
135 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
136     implementation of support for (*MARK) will need an extra pointer on the
137 ph10 501 stack; I have reserved it now, so that the stack frame size does not
138     decrease.
139 ph10 507
140     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
141     item in branch that calls a recursion is a subroutine call - as in the
142 ph10 503 second branch in the above example - was incorrectly given the compile-
143     time error "recursive call could loop indefinitely" because pcre_compile()
144 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
146 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
147 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
148 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
149 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
150 ph10 491
151 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
152 ph10 492
153 ph10 507
154 ph10 489 Version 8.01 19-Jan-2010
155     ------------------------
156 ph10 471
157     1. If a pattern contained a conditional subpattern with only one branch (in
158 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
159 ph10 473 computed the wrong minimum data length (which is of course zero for such
160 ph10 489 subpatterns). This could cause incorrect "no match" results.
161 ph10 473
162     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
163 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
164     "internal error: code overflow at offset...". This happened only when
165 ph10 473 the reset was to the original external option setting. (An optimization
166     abstracts leading options settings into an external setting, which was the
167 ph10 472 cause of this.)
168 ph10 471
169 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
170     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
171     assertion pattern did not match (meaning that the assertion was true), it
172     was incorrectly treated as false if the SKIP had been reached during the
173     matching. This also applied to assertions used as conditions.
174 ph10 471
175 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
176     assertion subpattern, including such a pattern used as a condition,
177     unpredictable results occurred, instead of the error return
179 ph10 478
180 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
181     situation when an empty string is matched. It now does the fancy magic
182 ph10 478 stuff that is necessary.
184     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
185 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
186 ph10 478
187 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
188     as part of something else:
189 ph10 478
190     (a) Change DEBUG to PCRE_DEBUG.
192     (b) In pcre_compile(), rename the member of the "branch_chain" structure
193     called "current" as "current_branch", to prevent a collision with the
194 ph10 475 Linux macro when compiled as a kernel module.
195 ph10 478
196     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
197     prevent a collision with the Linux macro when compiled as a kernel
198 ph10 475 module.
199 ph10 478
200 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
201     cast potentially large values to (double). This has been changed to that
202 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
203     instead, thus avoiding the use of floating point arithmetic. (There is no
204     other use of FP in PCRE.) If int64_t is not found, the fallback is to
205     double.
207     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
208 ph10 476 2005 (difference between two addresses compared to an unsigned value).
209 ph10 473
210 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
211     custom one, because of the following reported problem in Windows:
212 ph10 473
213 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
214 ph10 489 under Win32.
215 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
216 ph10 489 therefore missing the function definition.
217 ph10 478 - The compiler thus generates a "C" signature for the test function.
218     - The linker fails to find the "C" function.
219     - PCRE fails to configure if asked to do so against libbz2.
220 ph10 486
221 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
222     messages were output:
223 ph10 478
224 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
225     rerunning libtoolize, to keep the correct libtool macros in-tree.
226     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
227 ph10 486
228 ph10 479 I have done both of these things.
229 ph10 486
230 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
231 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
232     runaway infinite recursion. I updated the discussion in the pcrestack man
233     page.
235     13. Now that we have gone to the x.xx style of version numbers, the minor
236     version may start with zero. Using 08 or 09 is a bad idea because users
237     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
238     interpreted as invalid octal numbers. I've updated the previous comment in
239     configure.ac, and also added a check that gives an error if 08 or 09 are
240 ph10 481 used.
241 ph10 486
242 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
243 ph10 483 causing partial matching to fail when the end of the subject matched \W
244     in a UTF-8 pattern where \W was quantified with a minimum of 3.
245 ph10 486
246 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
247 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
248 ph10 483 their definitions. The declarations used "const uschar *" and the
249     definitions used USPTR. Even though USPTR is normally defined as "const
250     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
251     reported that: "This difference in casting confuses some C++ compilers, for
252     example, SunCC recognizes above declarations as different functions and
253 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
254 ph10 483 USPTR.
255 ph10 486
256     16. GNU libtool is named differently on some systems. The autogen.sh script now
257 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
258     (FreeBSD).
259 ph10 478
260 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
261     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
262     comment: "Figure out how to create a longlong from a string: strtoll and
263     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
264     instance, but it only takes 2 args instead of 3!"
265 ph10 479
266 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
267     specification, with a corresponding code fix. A pattern such as
268     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
269     refers, was giving matches when it shouldn't. For example, xa=xaaa would
270     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
271     same bug. Such groups have to be quantified to be useful, or contained
272     inside another quantified group. (If there's no repetition, the reference
273     can never match.) The problem arises because, having left the group and
274     moved on to the rest of the pattern, a later failure that backtracks into
275     the group uses the captured value from the final iteration of the group
276     rather than the correct earlier one. I have fixed this in PCRE by forcing
277     any group that contains a reference to itself to be an atomic group; that
278     is, there cannot be any backtracking into it once it has completed. This is
279     similar to recursive and subroutine calls.
280 ph10 486
281 ph10 488
282 ph10 469 Version 8.00 19-Oct-09
283 ph10 418 ----------------------
285     1. The table for translating pcre_compile() error codes into POSIX error codes
286 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
287     being within the table. This could lead to an OK return being given in
288 ph10 418 error.
289 ph10 461
290     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
291     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
292     in a Windows environment.
294 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
295     zero, as does GNU grep. However, pcregrep was also printing all files when
296     --files-with-matches was added. Now, when both options are given, it prints
297     counts only for those files that have at least one match. (GNU grep just
298 ph10 461 prints the file name in this circumstance, but including the count seems
299     more useful - otherwise, why use --count?) Also ensured that the
300 ph10 420 combination -clh just lists non-zero counts, with no names.
301 ph10 461
302     4. The long form of the pcregrep -F option was incorrectly implemented as
303     --fixed_strings instead of --fixed-strings. This is an incompatible change,
304     but it seems right to fix it, and I didn't think it was worth preserving
305     the old behaviour.
307     5. The command line items --regex=pattern and --regexp=pattern were not
308 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
309 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
310 ph10 422 which are compatible with GNU grep; these now work.
311 ph10 461
312     6. No libpcreposix.pc file was created for pkg-config; there was just
313 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
314 ph10 461
315 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
316 ph10 461 when UCP support is not needed, by modifying the Python script that
317 ph10 425 generates it from Unicode data files. This should not matter if the module
318     is correctly used as a library, but I received one complaint about 50K of
319     unwanted data. My guess is that the person linked everything into his
320     program rather than using a library. Anyway, it does no harm.
321 ph10 461
322 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
323 ph10 461 was a minimum greater than 1 for a wide character in a possessive
324 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
325     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
326     character. Chaos in the form of incorrect output or a compiling loop could
327     result.
328 ph10 461
329 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
330 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
331 ph10 426 partially matched by this function. In addition, if there are at least two
332 ph10 435 slots in the offset vector, the offset of the earliest inspected character
333     for the match and the offset of the end of the subject are set in them when
334 ph10 461 PCRE_ERROR_PARTIAL is returned.
336 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
337     synonymous with PCRE_PARTIAL, for backwards compatibility, and
338     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
339 ph10 462 and may be more useful for multi-segment matching.
340 ph10 461
341     11. Partial matching with pcre_exec() is now more intuitive. A partial match
342     used to be given if ever the end of the subject was reached; now it is
343     given only if matching could not proceed because another character was
344     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
345     string "Z", which now yields "no match" instead of "partial match". In the
346     case of pcre_dfa_exec(), "no match" is given if every matching path for the
347     final character ended with (*FAIL).
349 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
350 ph10 461 if the pattern had a "must contain" character that was already found in the
351 ph10 428 earlier partial match, unless partial matching was again requested. For
352     example, with the pattern /dog.(body)?/, the "must contain" character is
353     "g". If the first part-match was for the string "dog", restarting with
354 ph10 435 "sbody" failed. This bug has been fixed.
355 ph10 461
356     13. The string returned by pcre_dfa_exec() after a partial match has been
357     changed so that it starts at the first inspected character rather than the
358     first character of the match. This makes a difference only if the pattern
359     starts with a lookbehind assertion or \b or \B (\K is not supported by
360     pcre_dfa_exec()). It's an incompatible change, but it makes the two
361 ph10 435 matching functions compatible, and I think it's the right thing to do.
362 ph10 461
363 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
364 ph10 461 so that the demonstration program is easily available in environments where
365     PCRE has not been installed from source.
367 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
368 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
369     library.
370 ph10 461
371 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
372 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
373 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
374 ph10 433 these options useful.
375 ph10 461
376     17. If a caller to the POSIX matching function regexec() passes a non-zero
377 ph10 438 value for nmatch with a NULL value for pmatch, the value of
378 ph10 461 nmatch is forced to zero.
380 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
381 ph10 461 the diff command, as RunTest does. It now checks in the same way as
382 ph10 437 RunTest, and also checks for the -b option.
383 ph10 461
384 ph10 438 19. If an odd number of negated classes containing just a single character
385     interposed, within parentheses, between a forward reference to a named
386 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
387     an internal error, complaining that it could not find the referenced
388 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
389 ph10 461 [The bug was that it was starting one character too far in when skipping
390     over the character class, thus treating the ] as data rather than
391     terminating the class. This meant it could skip too much.]
393 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
394 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
395 ph10 442 to have an empty string match not at the start, even when the pattern is
396 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
398 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
399 ph10 461 than the maximum at the outer level, the higher number was returned, but
400     with unset values at the outer level. The correct (outer level) value is
401 ph10 446 now given.
402 ph10 461
403 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
404     PCRE did not set those parentheses (unlike Perl). I have now found a way to
405     make it do so. The string so far is captured, making this feature
406     compatible with Perl.
407 ph10 461
408     23. The tests have been re-organized, adding tests 11 and 12, to make it
409 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
410 ph10 461
411 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
412 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
413     does. Neither allows recursion.
415     25. I finally figured out how to implement a request to provide the minimum
416     length of subject string that was needed in order to match a given pattern.
417     (It was back references and recursion that I had previously got hung up
418     on.) This code has now been added to pcre_study(); it finds a lower bound
419 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
420     bound, but using it to avoid searching strings that are too short does give
421     some useful speed-ups. The value is available to calling programs via
422     pcre_fullinfo().
423 ph10 461
424 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
425     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
426     study optimizations had never been tested with that matching function.
427     Oops. What is worse, even when it was passed study data, there was a bug in
428     pcre_dfa_exec() that meant it never actually used it. Double oops. There
429     were also very few tests of studied patterns with pcre_dfa_exec().
430 ph10 461
431 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
432     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
433     on the other side of the coin, they are no longer allowed to have different
434     names, because these cannot be distinguished in PCRE, and this has caused
435     confusion. (This is a difference from Perl.)
436 ph10 461
437     28. When duplicate subpattern names are present (necessarily with different
438     numbers, as required by 27 above), and a test is made by name in a
439     conditional pattern, either for a subpattern having been matched, or for
440     recursion in such a pattern, all the associated numbered subpatterns are
441 ph10 459 tested, and the overall condition is true if the condition is true for any
442     one of them. This is the way Perl works, and is also more like the way
443     testing by number works.
444 ph10 418
445 ph10 461
446 ph10 412 Version 7.9 11-Apr-09
447 ph10 376 ---------------------
449 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
450 ph10 376 (pcretest), all targets were linked against these libraries. This included
451     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
452     libraries. This caused unwanted dependencies to be created. This problem
453 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
454 ph10 376 pcretest is linked with readline.
455 ph10 392
456 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
457     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
458     moved outside it again, because FALSE and TRUE are already defined in AIX,
459     but BOOL is not.
460 ph10 392
461     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
462 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
463 ph10 392
464 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
465     hyphens) following file names and line numbers when outputting matching
466 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
467 ph10 376 wording for the --colour (or --color) option.
468 ph10 392
469 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
470     was not coloured; this is different to GNU grep, so I have changed it to be
471     the same.
472 ph10 392
473 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
474 ph10 392 each matching line was coloured. Now it goes on to look for further matches
475     of any of the test patterns, which is the same behaviour as GNU grep.
477     7. A pattern that could match an empty string could cause pcregrep to loop; it
478     doesn't make sense to accept an empty string match in pcregrep, so I have
479 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
480     seems to be how GNU grep behaves.
481 ph10 392
482 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
483 ph10 392 start or after a newline", because the conditional assertion was not being
484     correctly handled. The rule now is that both the assertion and what follows
485     in the first alternative must satisfy the test.
487 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
488 ph10 399 condition was an assertion, PCRE could crash during matching, both with
489     pcre_exec() and pcre_dfa_exec().
490 ph10 392
491     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
492     used for matching.
494     11. Unicode property support in character classes was not working for
495 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
496 ph10 388
497 ph10 392 12. Added the -M command line option to pcretest.
499 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
500 ph10 389
501     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
502 ph10 390
503 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
504 ph10 390 wrapper.
505 ph10 392
506 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
507 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
508 ph10 391 string constants.
509 ph10 405
510 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
511     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
512 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
513     these, but not everybody uses configure.
515     19. A conditional group that had only one branch was not being correctly
516     recognized as an item that could match an empty string. This meant that an
517     enclosing group might also not be so recognized, causing infinite looping
518     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
519     with the subject "ab", where knowledge that the repeated group can match
520 ph10 396 nothing is needed in order to break the loop.
521 ph10 405
522 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
523 ph10 405 exec(), but without supplying a callout function, matching went wrong.
525     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
526     leak if the size of the offset vector was greater than 30. When the vector
527     is smaller, the saved offsets during recursion go onto a local stack
528     vector, but for larger vectors malloc() is used. It was failing to free
529     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
530 ph10 400 error, in fact).
531 ph10 405
532 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
533 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
534     problem, but was untidy.
535 ph10 376
536 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
537     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
538     included within another project.
539 ph10 411
540 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
541     slightly modified by me:
542 ph10 411
543     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
544     not building pcregrep.
546 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
547 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
549 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
550     duplicate group numbers, could behave incorrectly or give incorrect errors,
551     because when scanning forward to find the reference group, PCRE was not
552     taking into account the duplicate group numbers. A pattern such as
553     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
554 ph10 411
555     26. Changed a few more instances of "const unsigned char *" to USPTR, making
556     the feature of a custom pointer more persuasive (as requested by a user).
557 ph10 416
558 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
559 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
560     pre-defined.
561 ph10 392
562 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
564 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
565     in the configuration summary.
566 ph10 405
567 ph10 411
568 ph10 374 Version 7.8 05-Sep-08
569 ph10 349 ---------------------
571     1. Replaced UCP searching code with optimized version as implemented for Ad
572     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
573 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
574     to 5 times on some simple patterns that I tested. Permission was given to
575     distribute the MultiStage2.py script that generates the tables (it's not in
576     the tarball, but is in the Subversion repository).
577 ph10 349
578 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
579     scripts.
580 ph10 358
581 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
582     a group with a zero qualifier. The result of the study could be incorrect,
583 ph10 358 or the function might crash, depending on the pattern.
585     4. Caseless matching was not working for non-ASCII characters in back
586 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
587 ph10 358 It now works when Unicode Property Support is available.
589 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
590     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
591     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
592 ph10 358 truncation.
593 ph10 349
594 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
596 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
597     pointers, in case they are 64-bit values.
598 ph10 371
599     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
600     test 2 if it fails.
602 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
603 ph10 371 and a #define of that name to empty if it is not externally set. This is to
604     allow users of MSVC to set it if necessary.
606     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
607 ph10 359 the convenience functions in the pcre_get.c source file.
608 ph10 371
609 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
610     could cause overwriting and/or a crash. This command provoked a crash in
611 ph10 371 some environments:
613     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
615 ph10 360 This potential security problem was recorded as CVE-2008-2371.
616 ph10 371
617 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
618     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
619 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
620 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
621     pcretest so that it places the subject at the end of its malloc-ed buffer.
622 ph10 371
623 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
624 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
626 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
627 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
628     first line. This applied both to normal and DFA matching.
630 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
631 ph10 371 /^[^d]*?$/8 failed to match "abc".
632 ph10 351
633 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
635     17. Make it more clear in the documentation that values returned from
636 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
637 ph10 357
638 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
639 ph10 368
640 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
641     supplied by Stefan Weber. I made a further small update for 7.8 because
642 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
643     replaced by pcre_ucd.c.
644 ph10 371
645 ph10 373
646 ph10 347 Version 7.7 07-May-08
647 ph10 321 ---------------------
649     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
650 ph10 345 a string to a long long, pretend we don't even have a long long." This is
651 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
652 ph10 345
653 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
654     pre-7.6 versions, which defined a global no_arg variable instead of putting
655 ph10 332 it in the RE class. (See also #8 below.)
656 ph10 345
657     3. Remove a line of dead code, identified by coverity and reported by Nuno
658     Lopes.
660 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
661 ph10 321
662 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
663 ph10 345 of files, instead of just to the final components.
665 ph10 324 (2) If there was more than one level of directory, the subdirectories were
666     skipped unless they satisfied the include/exclude conditions. This is
667     inconsistent with GNU grep (and could even be seen as contrary to the
668     pcregrep specification - which I improved to make it absolutely clear).
669     The action now is always to scan all levels of directory, and just
670     apply the include/exclude patterns to regular files.
671 ph10 345
672 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
673 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
675 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
676 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
677 ph10 326 doesn't support NULs in patterns.
678 ph10 345
679     7. Added some missing "const"s to declarations of static tables in
680     pcre_compile.c and pcre_dfa_exec.c.
682 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
683 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
684 ph10 345 first patch. And a third patch - this was a messy problem.)
685 ph10 321
686 ph10 345 9. Applied Craig's patch to remove the use of push_back().
688 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
689     matching function regexec().
690 ph10 345
691     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
692     which, however, unlike Perl's \g{...}, are subroutine calls, not back
693 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
694     Oniguruma does).
695 ph10 345
696     12. Previously, a group with a zero repeat such as (...){0} was completely
697 ph10 335 omitted from the compiled regex. However, this means that if the group
698     was called as a subroutine from elsewhere in the pattern, things went wrong
699 ph10 345 (an internal error was given). Such groups are now left in the compiled
700     pattern, with a new opcode that causes them to be skipped at execution
701 ph10 335 time.
702 ph10 345
703 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
704     to the way PCRE behaves:
705 ph10 345
706 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
707 ph10 345
708     (b) A back reference to an unmatched subpattern matches an empty string
709 ph10 336 (Perl fails the current match path).
710 ph10 345
711 ph10 341 (c) A data ] in a character class must be notated as \] because if the
712 ph10 345 first data character in a class is ], it defines an empty class. (In
713 ph10 341 Perl it is not possible to have an empty class.) The empty class []
714     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
715     The negative empty class [^] matches any one character, independently
716     of the DOTALL setting.
717 ph10 345
718     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
719 ph10 340 non-existent subpattern following a character class starting with ']' and
720     containing () gave an internal compiling error instead of "reference to
721     non-existent subpattern". Fortunately, when the pattern did exist, the
722 ph10 345 compiled code was correct. (When scanning forwards to check for the
723 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
724 ph10 345 the class, so got the count wrong. When actually compiling, the reference
725 ph10 340 was subsequently set up correctly.)
726 ph10 345
727 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
728 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
729     other assertions are supported. I have made pcre_dfa_exec() support
730     (*FAIL).
732 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
733 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
734     cannot be changed at match time, I realized I could make a small
735     improvement to matching performance by compiling OP_ALLANY instead of
736     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
737     on the OP_ANY path.
739     17. Compiling pcretest on Windows with readline support failed without the
740 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
741 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
743 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
744 ph10 345 ncurses library to be included for pcretest when ReadLine support is
745     requested, but also to allow for it to be overridden. This patch came from
746     Daniel Bergström.
747 ph10 347
748 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
749 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
750     any errors with the current Unicode tables. Thanks to Peter Kankowski for
751     spotting this.
752 ph10 324
753 ph10 332
754 ph10 319 Version 7.6 28-Jan-08
755 ph10 300 ---------------------
757 ph10 302 1. A character class containing a very large number of characters with
758     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
759     overflow.
760 ph10 309
761     2. Patch to cut out the "long long" test in pcrecpp_unittest when
762     HAVE_LONG_LONG is not defined.
764 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
765 ph10 304 bring them up to date and include new features. This patch includes:
766 ph10 309
767 ph10 304 - Fixed PH's badly added libz and libbz2 support.
768     - Fixed a problem with static linking.
769 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
770 ph10 304 - Fixed dftables problem and added an option.
771     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
773     - Added readline support for pcretest.
774 ph10 309 - Added an listing of the option settings after cmake has run.
776 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
777     "pcre.dll" under mingw when using Configure/Make. I added stuff to
778     Makefile.am that cause it to include this special target, without
779     affecting anything else. Note that the same mingw target plus all
780     the other distribution libraries and programs are now supported
781     when configuring with CMake (see 6 below) instead of with
782     Configure/Make.
783 ph10 309
784 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
785     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
786 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
787     solves the problem, but it does no harm.
788 ph10 313
789 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
790 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
791 ph10 314 with CMake, and also correct the comment about stack recursion.
792 ph10 313
793 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
794 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
795     of a program that users should build themselves after PCRE is installed, so
796     building it automatically is not really right. What is more, it gave
797 ph10 312 trouble in some build environments.
798 ph10 300
799 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
800 ph10 308
801 ph10 319
802 ph10 298 Version 7.5 10-Jan-08
803 ph10 263 ---------------------
805     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
806     values in parens when parsing an RE using the C++ wrapper."
807 ph10 286
808 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
809     Characters greater than 255 were excluded from the class instead of being
810     included.
811 ph10 286
812     3. The same bug as (2) above applied to negated POSIX classes such as
813 ph10 265 [:^space:].
814 ph10 286
815 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
816     defined or documented. It seems to have been a typo for PCRE_STATIC, so
817 ph10 286 I have changed it.
819 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
820 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
821     first named subpattern whose name started with "a" (in other words, the
822 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
823     expected" is now given for (?&) (a zero-length name), and this patch also
824     makes it give the same error for \k'' (previously it complained that that
825     was a reference to a non-existent subpattern).
826 ph10 286
827 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
828 ph10 286 this is right because (?- can be followed by option settings as well as by
829 ph10 269 digits. I have, however, made the messages clearer.
830 ph10 286
831 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
832     than the number used in the conditional) now cause a compile-time error.
833     This is actually not compatible with Perl, which accepts such patterns, but
834     treats the conditional as always being FALSE (as PCRE used to), but it
835     seems to me that giving a diagnostic is better.
836 ph10 286
837 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
838 ph10 275 and messages.
839 ph10 286
840     9. Fix two occurrences of "backslash" in comments that should have been
841     "backspace".
843     10. Remove two redundant lines of code that can never be obeyed (their function
844     was moved elsewhere).
846     11. The program that makes PCRE's Unicode character property table had a bug
847     which caused it to generate incorrect table entries for sequences of
848 ph10 277 characters that have the same character type, but are in different scripts.
849 ph10 286 It amalgamated them into a single range, with the script of the first of
850 ph10 277 them. In other words, some characters were in the wrong script. There were
851     thirteen such cases, affecting characters in the following ranges:
852 ph10 286
853 ph10 277 U+002b0 - U+002c1
854     U+0060c - U+0060d
855 ph10 286 U+0061e - U+00612
856 ph10 277 U+0064b - U+0065e
857     U+0074d - U+0076d
858     U+01800 - U+01805
859     U+01d00 - U+01d77
860     U+01d9b - U+01dbf
861     U+0200b - U+0200f
862     U+030fc - U+030fe
863     U+03260 - U+0327f
864     U+0fb46 - U+0fbb1
865     U+10450 - U+1049d
866 ph10 286
867 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
868     compatible with GNU grep in that, if there was more than one match in a
869     line, it showed only the first of them. It now behaves in the same way as
870     GNU grep.
871 ph10 286
872     13. If the -o and -v options were combined for pcregrep, it printed a blank
873     line for every non-matching line. GNU grep prints nothing, and pcregrep now
874     does the same. The return code can be used to tell if there were any
875     non-matching lines.
877 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
879     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
880 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
881 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
882     and both kinds of lookbehind were skipped).
884 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
885 ph10 284 inclusion of <windows.h> to before rather than after the definition of
886     INVALID_FILE_ATTRIBUTES (patch from David Byron).
887 ph10 263
888 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
889 ph10 286 character property caused pcre_compile() to compile bad code, which led at
890     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
891     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
892     caused the error; without that there was no problem.
893 ph10 263
894 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
895 ph10 286
896 ph10 289 19. Added --enable-pcretest-libreadline.
897 ph10 286
898 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
899 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
900 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
901     later patch that removed the other one (the right fix) and added unit tests
902     that check the return values (which was not done before).
903 ph10 292
904 ph10 291 21. Several CMake things:
905 ph10 287
906 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
907 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
908 ph10 288
909 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
910     linked with the newly-built libraries, not previously installed ones.
911 ph10 291
913 ph10 298
914     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
915     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
916     UTF-8 newline character). The key issue is that the pattern starts .*;
917     this means that the match must be either at the beginning, or after a
918     newline. The bug was in the code for advancing after a failed match and
919     checking that the new position followed a newline. It was not taking
920 ph10 294 account of UTF-8 characters correctly.
921 ph10 298
922     23. PCRE was behaving differently from Perl in the way it recognized POSIX
923     character classes. PCRE was not treating the sequence [:...:] as a
924     character class unless the ... were all letters. Perl, however, seems to
925     allow any characters between [: and :], though of course it rejects as
926     unknown any "names" that contain non-letters, because all the known class
927     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
928     for example, whereas PCRE did not - it did not recognize a POSIX character
929     class. This seemed a bit dangerous, so the code has been changed to be
930     closer to Perl. The behaviour is not identical to Perl, because PCRE will
931     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
932     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
933     Perl does, and where it didn't before.
935 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
936     Windows environments %n is disabled by default.
937 ph10 292
939 ph10 260 Version 7.4 21-Sep-07
940 ph10 230 ---------------------
942     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
943 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
944     LF". That isn't really right - the whole point of the change was to try to
945     help when there was an actual mention of one of the two characters. So now
946     the change happens only if \r or \n (or a literal CR or LF) character is
947 ph10 230 encountered.
948 ph10 231
949     2. The 32-bit options word was also used for 6 internal flags, but the numbers
950     of both had grown to the point where there were only 3 bits left.
951     Fortunately, there was spare space in the data structure, and so I have
952     moved the internal flags into a new 16-bit field to free up more option
953 ph10 230 bits.
954 ph10 231
955     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
956     but did not set the internal JCHANGED flag - either of these is enough to
957     control the way the "get" function works - but the PCRE_INFO_JCHANGED
958     facility is supposed to tell if (?J) was ever used, so now (?J) at the
959 ph10 230 start sets both bits.
961 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
962     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
963 ph10 230
964 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
966     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
967 ph10 233 compatibility, even though it is no longer used.
968 ph10 243
969     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
970 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
971 ph10 259 windows.h file is present (where different names are used). [This was
972 ph10 257 reversed later after testing - see 16 below.]
973 ph10 243
974     8. Changed all #include <config.h> to #include "config.h". There were also
975 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
976 ph10 243
977 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
978 ph10 243 sequence off the lines that it output.
980     10. It was pointed out to me that arrays of string pointers cause lots of
981     relocations when a shared library is dynamically loaded. A technique of
982     using a single long string with a table of offsets can drastically reduce
983     these. I have refactored PCRE in four places to do this. The result is
984 ph10 240 dramatic:
985 ph10 243
986 ph10 240 Originally: 290
987     After changing UCP table: 187
988 ph10 243 After changing error message table: 43
989 ph10 240 After changing table of "verbs" 36
990     After changing table of Posix names 22
991 ph10 243
992 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
993 ph10 247
994 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
995 ph10 247 unicode-properties was also set.
997 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
998 ph10 231
999 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1000     checked only for CRLF.
1001 ph10 233
1002 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
1004 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1005 ph10 253
1006 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1007 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1008     entirely. This removes changes made in 7 above.
1009 ph10 256
1010 ph10 261 17. The CMake files have been updated, and there is now more information about
1011     building with CMake in the NON-UNIX-USE document.
1012 ph10 257
1013 ph10 261
1014 ph10 228 Version 7.3 28-Aug-07
1015 ph10 157 ---------------------
1017 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1018     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1019     brackets there is not right, since it causes compilers to look for an
1020     installed pcre.h, not the version that is in the source that is being
1021     compiled (which of course may be different). I have changed it back to:
1022 ph10 197
1023 ph10 189 #include "pcre.h"
1024 ph10 197
1025     I have a vague recollection that the change was concerned with compiling in
1026     different directories, but in the new build system, that is taken care of
1027     by the VPATH setting the Makefile.
1029 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1030     when the subject happened to end in the byte 0x85 (e.g. if the last
1031     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1032     characters but of course it shouldn't be taken as a newline when it is part
1033     of another character. The bug was that, for an unlimited repeat of . in
1034     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1035     characters when looking for a newline.
1036 ph10 197
1037     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1039     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1040     in debug output.
1042 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1043     long printing in the pcrecpp unittest when running under MinGW.
1044 ph10 189
1045 ph10 197 6. ESC_K was left out of the EBCDIC table.
1046 ph10 189
1047 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1048     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1049     limit also applies to "virtual nesting" when a pattern is recursive, and in
1050     this case 1000 isn't so big. I have been able to remove this limit at the
1051     expense of backing off one optimization in certain circumstances. Normally,
1052     when pcre_exec() would call its internal match() function recursively and
1053     immediately return the result unconditionally, it uses a "tail recursion"
1054     feature to save stack. However, when a subpattern that can match an empty
1055     string has an unlimited repetition quantifier, it no longer makes this
1056     optimization. That gives it a stack frame in which to save the data for
1057     checking that an empty string has been matched. Previously this was taken
1058     from the 1000-entry workspace that had been reserved. So now there is no
1059     explicit limit, but more stack is used.
1060 ph10 189
1061 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1062     syntax that is required for Windows, and which was going wrong for the
1063     pcreposix and pcrecpp parts of the library. These were overlooked when this
1064     problem was solved for the main library.
1065 ph10 197
1066 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1067     the size of patterns that contain repeated groups with explicit upper
1068     limits. As the maximum quantifier is 65535, the maximum group length was
1069     set at 30,000 so that the product of these two numbers did not overflow a
1070     32-bit integer. However, it turns out that people want to use groups that
1071     are longer than 30,000 bytes (though not repeat them that many times).
1072     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1073     made it possible to implement the integer overflow checks in a much more
1074     dynamic way, which I have now done. The artificial limitation on group
1075     length has been removed - we now have only the limit on the total length of
1076     the compiled pattern, which depends on the LINK_SIZE setting.
1077 ph10 208
1078     10. Fixed a bug in the documentation for get/copy named substring when
1079     duplicate names are permitted. If none of the named substrings are set, the
1080     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1081     empty string.
1083     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1084     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1085     because the ] is interpreted as the first data character and the
1086     terminating ] is not found. PCRE has been made compatible with Perl in this
1087     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1088     cause memory overwriting.
1090 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1091     string has been matched (to stop an infinite loop). It was not recognizing
1092 ph10 208 a conditional subpattern that could match an empty string if that
1093 ph10 206 subpattern was within another subpattern. For example, it looped when
1094 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1095 ph10 206 condition was not nested. This bug has been fixed.
1096 ph10 208
1097 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1098     past the start of the subject in the presence of bytes with the top bit
1099     set, for example "\x8aBCD".
1100 ph10 211
1101 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1102     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1103 ph10 200
1104 ph10 211 14. Optimized (?!) to (*FAIL).
1105 ph10 202
1106 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1107     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1108     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1109     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1110     does: it's just the validity check that is more restrictive.
1111 ph10 220
1112     16. Inserted checks for integer overflows during escape sequence (backslash)
1113     processing, and also fixed erroneous offset values for syntax errors during
1114     backslash processing.
1116 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1117 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1119 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1120     caused an overrun.
1121 ph10 220
1122     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1123     something other than just ASCII characters) inside a group that had an
1124     unlimited repeat caused a loop at compile time (while checking to see
1125     whether the group could match an empty string).
1127 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1128     [\P{Any}] did so. (Error in the code for printing property names.)
1129 ph10 210
1130 ph10 220 21. An orphan \E inside a character class could cause a crash.
1132     22. A repeated capturing bracket such as (A)? could cause a wild memory
1133 ph10 218 reference during compilation.
1134 ph10 220
1135     23. There are several functions in pcre_compile() that scan along a compiled
1136     expression for various reasons (e.g. to see if it's fixed length for look
1137 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1138 ph10 220 present in the pattern. These operators have additional parameters compared
1139     with \d, etc, and these were not being taken into account when moving along
1140 ph10 218 the compiled data. Specifically:
1141 ph10 220
1142     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1143     length.
1145     (b) An item such as \pL+ within a repeated group could cause crashes or
1146 ph10 218 loops.
1147 ph10 220
1148 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1149 ph10 220 "reference to non-existent subpattern" error.
1151 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1153 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1154 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1155 ph10 211
1156 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1157 ph10 218
1158 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1159 ph10 223 character were causing crashes (broken optimization).
1160 ph10 227
1161 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1162 ph10 227 \p or \P) caused a compile-time loop.
1164 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1165     break. For example, the unstudied pattern [\r\n]A does not match the string
1166     "\r\nA" because change 7.0/46 below moves the current point on by two
1167     characters after failing to match at the start. However, the pattern \nA
1168 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1169     the same is true. There doesn't seem any very clean way out of this, but
1170     what I have chosen to do makes the common cases work: PCRE now takes note
1171     of whether there can be an explicit match for \r or \n anywhere in the
1172     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1173     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1174     pattern has explicit CR or LF references.
1175 ph10 222
1176 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1177 ph10 223
1178 ph10 227
1179 ph10 189 Version 7.2 19-Jun-07
1180     ---------------------
1182 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1183     which is apparently normally available under Windows.
1184 ph10 159
1185     2. Re-jig the pcregrep tests with different newline settings in an attempt
1186     to make them independent of the local environment's newline setting.
1187 ph10 157
1188 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1189 ph10 165
1190 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1191     was not 2, because the output contained actual offsets. The recent new
1192 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1193     usable with all link sizes.
1195 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1196     stack recursion. This gives a massive performance boost under BSD, but just
1197 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1198 ph10 164 in all cases.
1199 ph10 172
1200 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1201 ph10 172
1202 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1203     recursion call. It refers to the nth most recently opened parentheses.
1204 ph10 172
1205 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1206 ph10 172 to be opened parentheses.
1208     (c) Conditions that refer to capturing parentheses can be specified
1209 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1210 ph10 172
1211 ph10 168 (d) \K resets the start of the current match so that everything before
1212 ph10 172 is not part of it.
1214 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1215 ph10 172
1216 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1217 ph10 172 reference syntax.
1218 ph10 182
1219 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1220 ph10 182 alternative starts with the same number.
1221 ph10 172
1222 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1224 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1227     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1228     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1229 ph10 170 for detecting groups that can match an empty string.
1230 ph10 159
1231 ph10 172 9. A pattern with a very large number of alternatives (more than several
1232     hundred) was running out of internal workspace during the pre-compile
1233     phase, where pcre_compile() figures out how much memory will be needed. A
1234     bit of new cunning has reduced the workspace needed for groups with
1235     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1236     workspace instead of running out of the 4096 that are available.
1237 ph10 182
1238 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1239 ph10 172
1240 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1241     The report of the bug said:
1242 ph10 182
1243 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1244     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1245 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1246 ph10 185
1247 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1248 ph10 185 it matched the wrong number of bytes.
1249 ph10 172
1250 ph10 179
1251 ph10 155 Version 7.1 24-Apr-07
1252 ph10 98 ---------------------
1254 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1255 ph10 122 that is more "standard", making use of automake and other Autotools. There
1256 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1257     on this.
1258 ph10 111
1259     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1260     for recursive directory scanning broke on some systems because the files
1261     are not scanned in any specific order and on different systems the order
1262     was different. A call to "sort" has been inserted into RunGrepTest for the
1263     approprate test as a short-term fix. In the longer term there may be an
1264 ph10 100 alternative.
1265 ph10 111
1266 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1267 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1268     people do their own conversions for various reasons). The problems
1269     concerned the use of low-level troff macros .br and .in. I have therefore
1270     removed all such uses from the man pages (some were redundant, some could
1271 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1272     HTML has been updated to handle .nf/.fi and to complain if it encounters
1273     .br or .in.
1274 ph10 111
1275 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1276 ph10 123 arranged for config.h to be included in the distribution, with the name
1277 ph10 111 config.h.generic, for the benefit of those who have to compile without
1278     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1280     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1281     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1282 ph10 127 makevp.bat for the current PCRE, using the additional files
1283 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1284 ph10 111
1285     6. A Windows user reported a minor discrepancy with test 2, which turned out
1286     to be caused by a trailing space on an input line that had got lost in his
1287 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1288 ph10 111
1289 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1290 ph10 111 that is needed.
1292 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1293     as "const" (a) because they are and (b) because it helps the PHP
1294     maintainers who have recently made a script to detect big data structures
1295 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1296     to update Builducptable as well, so it won't revert if ucptable.h is ever
1297 ph10 105 re-created.
1298 ph10 111
1299     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1300 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1301 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1302     support is not required. This saves 1.5-2K of code, which is important in
1303 ph10 107 some applications.
1304 ph10 111
1305 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1306 ph10 111 so as not to refer to the tables, even though these functions will never be
1307     called when UTF-8 support is disabled. Otherwise there are problems with a
1308     shared library.
1310 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1312     (a) It was defining its arguments as char * instead of void *.
1314 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1315     a long time ago when I wrote it, but is no longer the case.
1317 ph10 118 The emulated memove() is provided for those environments that have neither
1318 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1319 ph10 118 is clearly not the case, as these two bugs were recently reported.
1320 ph10 123
1321 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1322 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1323     pages, and it removes trailing spaces from listed files. It also creates
1324     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1325     case, it wraps all the #defines with #ifndefs. This script should be run
1326 ph10 111 before "make dist".
1327 ph10 123
1328 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1329     with Unicode property support.
1330 ph10 123
1331     (a) For a maximizing quantifier, if the two different cases of the
1332     character were of different lengths in their UTF-8 codings (there are
1333     some cases like this - I found 11), and the matching function had to
1334 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1335     were both the same length.
1336 ph10 123
1337     (b) When PCRE was configured to use the heap rather than the stack for
1338     recursion during matching, it was not correctly preserving the data for
1339     the other case of a UTF-8 character when checking ahead for a match
1340     while processing a minimizing repeat. If the check also involved
1341 ph10 115 matching a wide character, but failed, corruption could cause an
1342     erroneous result when trying to check for a repeat of the original
1343     character.
1344 ph10 123
1345 ph10 116 13. Some tidying changes to the testing mechanism:
1346 ph10 98
1347 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1348     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1349 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1350     this for UTF-8.) The configure.ac script no longer substitutes the
1351     relevant variables.
1353 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1354     with length and offset values. This means that the output is different
1355     for different internal link sizes. Test 2 is skipped for link sizes
1356     other than 2 because of this, bypassing the problem. Unfortunately,
1357     there was also a test in test 3 (the locale tests) that used /B and
1358 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1359     I have added a new /Z option to pcretest that replaces the length and
1360     offset values with spaces. This is now used to make test 3 independent
1361 ph10 122 of link size. (Test 2 will be tidied up later.)
1362 ph10 123
1363     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1364 ph10 122 segmentation fault instead of returning the appropriate error message.
1365 ph10 134
1366 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1367 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1368     This doesn't seem right; it now treats the CRLF combination as the line
1369     ending, and so does not match in that case. It's only a pattern such as ^$
1370     that would hit this one: something like ^ABC$ would have failed after \r
1371     and then tried again after \r\n.
1373 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1374 ph10 134 in an attempt to make files that differ only in their line terminators
1375     compare equal. This works on Linux.
1376 ph10 142
1377 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1378     as it exited. This is now fixed, thanks to valgrind.
1379 ph10 142
1380 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1381 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1382     was because its rules for how to advance for /g after matching an empty
1383 ph10 143 string at the end of a line did not allow for this case. They now check for
1384     it specially.
1385 ph10 150
1386     20. pcretest is supposed to handle patterns and data of any length, by
1387     extending its buffers when necessary. It was getting this wrong when the
1388 ph10 147 buffer for a data line had to be extended.
1389 ph10 150
1390 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1391 ph10 150 CRLF as a newline sequence.
1392 ph10 152
1393 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1394 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1395     I have nevertheless tidied it up.
1396 ph10 111
1397 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1398 ph10 123
1399 ph10 153 24. Added a man page for pcre-config.
1400 ph10 152
1401 ph10 153
1402 nigel 93 Version 7.0 19-Dec-06
1403     ---------------------
1405     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1406     moving to gcc 4.1.1.
1408     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1409     sys/time.h, which is documented as needed for this function. It doesn't
1410     seem to matter on Linux, but it showed up on some releases of OS X.
1412     3. It seems that there are systems where bytes whose values are greater than
1413     127 match isprint() in the "C" locale. The "C" locale should be the
1414     default when a C program starts up. In most systems, only ASCII printing
1415     characters match isprint(). This difference caused the output from pcretest
1416     to vary, making some of the tests fail. I have changed pcretest so that:
1418     (a) When it is outputting text in the compiled version of a pattern, bytes
1419     other than 32-126 are always shown as hex escapes.
1421     (b) When it is outputting text that is a matched part of a subject string,
1422     it does the same, unless a different locale has been set for the match
1423     (using the /L modifier). In this case, it uses isprint() to decide.
1425     4. Fixed a major bug that caused incorrect computation of the amount of memory
1426     required for a compiled pattern when options that changed within the
1427     pattern affected the logic of the preliminary scan that determines the
1428     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1429     that the computed length was too small. The symptoms of this bug were
1430     either the PCRE error "internal error: code overflow" from pcre_compile(),
1431     or a glibc crash with a message such as "pcretest: free(): invalid next
1432     size (fast)". Examples of patterns that provoked this bug (shown in
1433     pcretest format) are:
1435     /(?-x: )/x
1436     /(?x)(?-x: \s*#\s*)/
1437     /((?i)[\x{c0}])/8
1438     /(?i:[\x{c0}])/8
1440     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1441     is now done differently.
1443     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1444     wrapper classes; (b) implement a new function in the C++ scanner that is
1445     more efficient than the old way of doing things because it avoids levels of
1446     recursion in the regex matching; (c) add a paragraph to the documentation
1447     for the FullMatch() function.
1449     6. The escape sequence \n was being treated as whatever was defined as
1450     "newline". Not only was this contrary to the documentation, which states
1451     that \n is character 10 (hex 0A), but it also went horribly wrong when
1452     "newline" was defined as CRLF. This has been fixed.
1454     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1455     was being set to -1 for the "end of line" case (supposedly a value that no
1456     character can have). Though this value is never used (the check for end of
1457     line is "zero bytes in current character"), it caused compiler complaints.
1458     I've changed it to 0xffffffff.
1460     8. In pcre_version.c, the version string was being built by a sequence of
1461     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1462     string (as it is for production releases) called a macro with an empty
1463     argument. The C standard says the result of this is undefined. The gcc
1464     compiler treats it as an empty string (which was what was wanted) but it is
1465     reported that Visual C gives an error. The source has been hacked around to
1466     avoid this problem.
1468     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1469     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1470     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1471     of them did).
1473     10. Originally, pcretest opened its input and output without "b"; then I was
1474     told that "b" was needed in some environments, so it was added for release
1475     5.0 to both the input and output. (It makes no difference on Unix-like
1476     systems.) Later I was told that it is wrong for the input on Windows. I've
1477     now abstracted the modes into two macros, to make it easier to fiddle with
1478     them, and removed "b" from the input mode under Windows.
1480     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1482     12. Added -help and --help to pcretest as an official way of being reminded
1483     of the options.
1485     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1486     and pcrecpp.cc because they annoy compilers at high warning levels.
1488     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1490     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1491     scripts are not C programs :-) and which was not noticed because it works
1492     on Linux.
1494     16. pcretest is supposed to handle any length of pattern and data line (as one
1495     line or as a continued sequence of lines) by extending its input buffer if
1496     necessary. This feature was broken for very long pattern lines, leading to
1497     a string of junk being passed to pcre_compile() if the pattern was longer
1498     than about 50K.
1500     17. I have done a major re-factoring of the way pcre_compile() computes the
1501     amount of memory needed for a compiled pattern. Previously, there was code
1502     that made a preliminary scan of the pattern in order to do this. That was
1503     OK when PCRE was new, but as the facilities have expanded, it has become
1504     harder and harder to keep it in step with the real compile phase, and there
1505     have been a number of bugs (see for example, 4 above). I have now found a
1506     cunning way of running the real compile function in a "fake" mode that
1507     enables it to compute how much memory it would need, while actually only
1508     ever using a few hundred bytes of working memory and without too many
1509     tests of the mode. This should make future maintenance and development
1510     easier. A side effect of this work is that the limit of 200 on the nesting
1511     depth of parentheses has been removed (though this was never a serious
1512     limitation, I suspect). However, there is a downside: pcre_compile() now
1513     runs more slowly than before (30% or more, depending on the pattern). I
1514     hope this isn't a big issue. There is no effect on runtime performance.
1516     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1517     newline (only possible for the last line of a file) and it was a
1518     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1520     19. Added additional timing features to pcretest. (1) The -tm option now times
1521     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1522     separate command line item, by a number that specifies the number of
1523     repeats to use when timing. The default is 50000; this gives better
1524     precision, but takes uncomfortably long for very large patterns.
1526     20. Extended pcre_study() to be more clever in cases where a branch of a
1527     subpattern has no definite first character. For example, (a*|b*)[cd] would
1528     previously give no result from pcre_study(). Now it recognizes that the
1529     first character must be a, b, c, or d.
1531     21. There was an incorrect error "recursive call could loop indefinitely" if
1532     a subpattern (or the entire pattern) that was being tested for matching an
1533     empty string contained only one non-empty item after a nested subpattern.
1534     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1535     incorrectly, because the \d was being skipped in the check.
1537     22. The pcretest program now has a new pattern option /B and a command line
1538     option -b, which is equivalent to adding /B to every pattern. This causes
1539     it to show the compiled bytecode, without the additional information that
1540     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1541     is the same as /B/I).
1543     23. A new optimization is now able automatically to treat some sequences such
1544     as a*b as a*+b. More specifically, if something simple (such as a character
1545     or a simple class like \d) has an unlimited quantifier, and is followed by
1546     something that cannot possibly match the quantified thing, the quantifier
1547     is automatically "possessified".
1549     24. A recursive reference to a subpattern whose number was greater than 39
1550     went wrong under certain circumstances in UTF-8 mode. This bug could also
1551     have affected the operation of pcre_study().
1553     25. Realized that a little bit of performance could be had by replacing
1554     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1556     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1558     27. Possessive quantifiers such as a++ were previously implemented by turning
1559     them into atomic groups such as ($>a+). Now they have their own opcodes,
1560     which improves performance. This includes the automatically created ones
1561     from 23 above.
1563     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1564     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1565     the first matched character to be a colon. This applied both to named and
1566     numbered groups.
1568     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1570     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1571     building PCRE on Windows easier, so I have included it in the distribution.
1573     31. There is now a check in pcretest against a ridiculously large number being
1574     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1575     loop, the loop is abandoned.
1577     32. Forward references to subpatterns in conditions such as (?(2)...) where
1578     subpattern 2 is defined later cause pcre_compile() to search forwards in
1579     the pattern for the relevant set of parentheses. This search went wrong
1580     when there were unescaped parentheses in a character class, parentheses
1581     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1583     33. "Subroutine" calls and backreferences were previously restricted to
1584     referencing subpatterns earlier in the regex. This restriction has now
1585     been removed.
1587     34. Added a number of extra features that are going to be in Perl 5.10. On the
1588     whole, these are just syntactic alternatives for features that PCRE had
1589     previously implemented using the Python syntax or my own invention. The
1590     other formats are all retained for compatibility.
1592     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1593     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1594     also .NET compatible.
1596     (b) A recursion or subroutine call to a named group can now be defined as
1597     (?&name) as well as (?P>name).
1599     (c) A backreference to a named group can now be defined as \k<name> or
1600     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1601     5.10, are also .NET compatible.
1603     (d) A conditional reference to a named group can now use the syntax
1604     (?(<name>) or (?('name') as well as (?(name).
1606     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1607     groups (named and numbered) that are never evaluated inline, but can be
1608     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1609     is always false. There may be only one alternative in such a group.
1611     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1612     as the simple (?(R). The condition is true only if the most recent
1613     recursion is that of the given number or name. It does not search out
1614     through the entire recursion stack.
1616     (g) The escape \gN or \g{N} has been added, where N is a positive or
1617     negative number, specifying an absolute or relative reference.
1619     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1620     some "unreachable code" warnings.
1622     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1623     things, this adds five new scripts.
1625     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1626     There were also incompatibilities regarding the handling of \Q..\E inside
1627     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1628     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1630     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1631     matches an empty string, and forcibly breaks the loop. There were bugs in
1632     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1633     against aaaa the result was just "a" rather than "aaaa", for example. Two
1634     separate and independent bugs (that affected different cases) have been
1635     fixed.
1637     39. Refactored the code to abolish the use of different opcodes for small
1638     capturing bracket numbers. This is a tidy that I avoided doing when I
1639     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1640     The new approach is not only tidier, it makes it possible to reduce the
1641     memory needed to fix the previous bug (38).
1643     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1644     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1645     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1646     mode.
1648     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1649     report.
1651     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1652     copy construction and assignment in the C++ wrapper.
1654     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1655     couple of bugs that could have given wrong results in the "--newline=crlf"
1656     case.
1658     44. Added a number of casts and did some reorganization of signed/unsigned int
1659     variables following suggestions from Dair Grant. Also renamed the variable
1660     "this" as "item" because it is a C++ keyword.
1662     45. Arranged for dftables to add
1664     #include "pcre_internal.h"
1666     to pcre_chartables.c because without it, gcc 4.x may remove the array
1667     definition from the final binary if PCRE is built into a static library and
1668     dead code stripping is activated.
1670     46. For an unanchored pattern, if a match attempt fails at the start of a
1671     newline sequence, and the newline setting is CRLF or ANY, and the next two
1672     characters are CRLF, advance by two characters instead of one.
1675 nigel 91 Version 6.7 04-Jul-06
1676     ---------------------
1678     1. In order to handle tests when input lines are enormously long, pcretest has
1679     been re-factored so that it automatically extends its buffers when
1680     necessary. The code is crude, but this _is_ just a test program. The
1681     default size has been increased from 32K to 50K.
1683     2. The code in pcre_study() was using the value of the re argument before
1684     testing it for NULL. (Of course, in any sensible call of the function, it
1685     won't be NULL.)
1687     3. The memmove() emulation function in pcre_internal.h, which is used on
1688     systems that lack both memmove() and bcopy() - that is, hardly ever -
1689     was missing a "static" storage class specifier.
1691     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1692     containing an extended class (one that cannot be represented by a bitmap
1693     because it contains high-valued characters or Unicode property items, e.g.
1694     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1695     pattern, but PCRE should not loop if you do not (it no longer does).
1696     [Detail: two cases were found: (a) a repeated subpattern containing an
1697     extended class; (b) a recursive reference to a subpattern that followed a
1698     previous extended class. It wasn't skipping over the extended class
1699     correctly when UTF-8 mode was not set.]
1701     5. A negated single-character class was not being recognized as fixed-length
1702     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1703     compile error "lookbehind assertion is not fixed length".
1705     6. The RunPerlTest auxiliary script was showing an unexpected difference
1706     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1707     write a Perl script that can interpret lines of an input file either as
1708     byte characters or as UTF-8, which is what "perltest" was being required to
1709     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1710     can't do is switch easily at run time between having the "use utf8;" pragma
1711     or not. In the end, I fudged it by using the RunPerlTest script to insert
1712     "use utf8;" explicitly for the UTF-8 tests.
1714     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1715     the end of the subject string, contrary to the documentation and to what
1716     Perl does. This was true of both matching functions. Now it matches only at
1717     the start of the subject and immediately after *internal* newlines.
1719     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1720     a pointer to an int instead of a pointer to an unsigned long int. This
1721     caused problems on 64-bit systems.
1723     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1724     instance of the 'standard' template library not being so standard".
1726     10. There was no check on the number of named subpatterns nor the maximum
1727     length of a subpattern name. The product of these values is used to compute
1728     the size of the memory block for a compiled pattern. By supplying a very
1729     long subpattern name and a large number of named subpatterns, the size
1730     computation could be caused to overflow. This is now prevented by limiting
1731     the length of names to 32 characters, and the number of named subpatterns
1732     to 10,000.
1734     11. Subpatterns that are repeated with specific counts have to be replicated in
1735     the compiled pattern. The size of memory for this was computed from the
1736     length of the subpattern and the repeat count. The latter is limited to
1737     65535, but there was no limit on the former, meaning that integer overflow
1738     could in principle occur. The compiled length of a repeated subpattern is
1739     now limited to 30,000 bytes in order to prevent this.
1741     12. Added the optional facility to have named substrings with the same name.
1743     13. Added the ability to use a named substring as a condition, using the
1744     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1745     are numbers (not recommended). Forward references are permitted.
1747     14. Added forward references in named backreferences (if you see what I mean).
1749     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1750     pattern could run off the end of the subject. For example, the pattern
1751     "(?s)(.{1,5})"8 did this with the subject "ab".
1753     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1754     PCRE_CASELESS was set when matching characters that were quantified with ?
1755     or *.
1757     17. A character class other than a single negated character that had a minimum
1758     but no maximum quantifier - for example [ab]{6,} - was not handled
1759     correctly by pce_dfa_exec(). It would match only one character.
1761     18. A valid (though odd) pattern that looked like a POSIX character
1762     class but used an invalid character after [ (for example [[,abc,]]) caused
1763     pcre_compile() to give the error "Failed: internal error: code overflow" or
1764     in some cases to crash with a glibc free() error. This could even happen if
1765     the pattern terminated after [[ but there just happened to be a sequence of
1766     letters, a binary zero, and a closing ] in the memory that followed.
1768     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1769     over the years. Originally (before any Unicode support), just the bottom 8
1770     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1771     output from "man perlunicode" includes this:
1773     The regular expression compiler produces polymorphic opcodes. That
1774     is, the pattern adapts to the data and automatically switches to
1775     the Unicode character scheme when presented with Unicode data--or
1776     instead uses a traditional byte scheme when presented with byte
1777     data.
1779     Sadly, a wide octal escape does not cause a switch, and in a string with
1780     no other multibyte characters, these octal escapes are treated as before.
1781     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1782     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1783     Unicode string.
1785     I have not perpetrated such confusion in PCRE. Up till now, it took just
1786     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1787     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1788     translate to the appropriate multibyte character.
1790     29. Applied some refactoring to reduce the number of warnings from Microsoft
1791     and Borland compilers. This has included removing the fudge introduced
1792     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1793     a warning about an unused variable.
1795     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1796     characters since release 4.0, because Perl (from release 5.004) does not.
1797     [Or at least, is documented not to: some releases seem to be in conflict
1798     with the documentation.] However, when a pattern was studied with
1799     pcre_study() and all its branches started with \s, PCRE still included VT
1800     as a possible starting character. Of course, this did no harm; it just
1801     caused an unnecessary match attempt.
1803     22. Removed a now-redundant internal flag bit that recorded the fact that case
1804     dependency changed within the pattern. This was once needed for "required
1805     byte" processing, but is no longer used. This recovers a now-scarce options
1806     bit. Also moved the least significant internal flag bit to the most-
1807     significant bit of the word, which was not previously used (hangover from
1808     the days when it was an int rather than a uint) to free up another bit for
1809     the future.
1811     23. Added support for CRLF line endings as well as CR and LF. As well as the
1812     default being selectable at build time, it can now be changed at runtime
1813     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1814     specify that it is scanning data with non-default line endings.
1816     24. Changed the definition of CXXLINK to make it agree with the definition of
1817     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1819     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1820     recursions. This makes a big different to stack usage for some patterns.
1822     26. If a subpattern containing a named recursion or subroutine reference such
1823     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1824     the space required for the compiled pattern went wrong and gave too small a
1825     value. Depending on the environment, this could lead to "Failed: internal
1826     error: code overflow at offset 49" or "glibc detected double free or
1827     corruption" errors.
1829     27. Applied patches from Google (a) to support the new newline modes and (b) to
1830     advance over multibyte UTF-8 characters in GlobalReplace.
1832     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1833     difference for some implementation of PCRE in some Windows version.
1835     29. Added some extra testing facilities to pcretest:
1837     \q<number> in a data line sets the "match limit" value
1838     \Q<number> in a data line sets the "match recursion limt" value
1839     -S <number> sets the stack size, where <number> is in megabytes
1841     The -S option isn't available for Windows.
1844 nigel 89 Version 6.6 06-Feb-06
1845     ---------------------
1847     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1848     in pcreposix.h. I have copied the definition from pcre.h.
1850     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1851     because pcre.h is no longer a built file.
1853     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1854     not normally included in the compiled code.
1857 nigel 87 Version 6.5 01-Feb-06
1858     ---------------------
1860     1. When using the partial match feature with pcre_dfa_exec(), it was not
1861     anchoring the second and subsequent partial matches at the new starting
1862     point. This could lead to incorrect results. For example, with the pattern
1863     /1234/, partially matching against "123" and then "a4" gave a match.
1865     2. Changes to pcregrep:
1867     (a) All non-match returns from pcre_exec() were being treated as failures
1868     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1869     error message is output. Some extra information is given for the
1871     probably the only errors that are likely to be caused by users (by
1872     specifying a regex that has nested indefinite repeats, for instance).
1873     If there are more than 20 of these errors, pcregrep is abandoned.
1875     (b) A binary zero was treated as data while matching, but terminated the
1876     output line if it was written out. This has been fixed: binary zeroes
1877     are now no different to any other data bytes.
1879     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1880     used to set a locale for matching. The --locale=xxxx long option has
1881     been added (no short equivalent) to specify a locale explicitly on the
1882     pcregrep command, overriding the environment variables.
1884     (d) When -B was used with -n, some line numbers in the output were one less
1885     than they should have been.
1887     (e) Added the -o (--only-matching) option.
1889     (f) If -A or -C was used with -c (count only), some lines of context were
1890     accidentally printed for the final match.
1892     (g) Added the -H (--with-filename) option.
1894     (h) The combination of options -rh failed to suppress file names for files
1895     that were found from directory arguments.
1897     (i) Added the -D (--devices) and -d (--directories) options.
1899     (j) Added the -F (--fixed-strings) option.
1901     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1903     (l) Added the --colo(u)r option.
1905     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1906     is not present by default.
1908     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1909     items such as (?R) or (?1), when the recursion could match a number of
1910     alternatives. If it matched one of the alternatives, but subsequently,
1911     outside the recursion, there was a failure, the code tried to back up into
1912     the recursion. However, because of the way PCRE is implemented, this is not
1913     possible, and the result was an incorrect result from the match.
1915     In order to prevent this happening, the specification of recursion has
1916     been changed so that all such subpatterns are automatically treated as
1917     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1919     4. I had overlooked the fact that, in some locales, there are characters for
1920     which isalpha() is true but neither isupper() nor islower() are true. In
1921     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1922     and ordfeminine) are like this. This affected the treatment of \w and \W
1923     when they appeared in character classes, but not when they appeared outside
1924     a character class. The bit map for "word" characters is now created
1925     separately from the results of isalnum() instead of just taking it from the
1926     upper, lower, and digit maps. (Plus the underscore character, of course.)
1928     5. The above bug also affected the handling of POSIX character classes such as
1929     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1930     permanent tables. Instead, the bit maps for such a class were previously
1931     created as the appropriate unions of the upper, lower, and digit bitmaps.
1932     Now they are created by subtraction from the [[:word:]] class, which has
1933     its own bitmap.
1935     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1936     It is created by subtracting the vertical space characters (\x09, \x0a,
1937     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1938     subtraction was done in the overall bitmap for a character class, meaning
1939     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1940     be recognized. This bug has been fixed.
1942     7. Patches from the folks at Google:
1944     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1945     real life, but is still worth protecting against".
1947     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1948     regular expressions".
1950     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1951     have it.
1953     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1954     "configure" and the latter not, in order to fix a problem somebody had
1955     with compiling the Arg class on HP-UX.
1957     (e) Improve the error-handling of the C++ wrapper a little bit.
1959     (f) New tests for checking recursion limiting.
1961     8. The pcre_memmove() function, which is used only if the environment does not
1962     have a standard memmove() function (and is therefore rarely compiled),
1963     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1964     returning a result (though PCRE never actually uses the result).
1966     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1967     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1968     returned instead of calling malloc() with an overflowing number that would
1969     most likely cause subsequent chaos.
1971     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1973     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1974     with this option is matched, the nmatch and pmatch options of regexec() are
1975     ignored.
1977     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1978     provided in case anyone wants to the the POSIX interface with UTF-8
1979     strings.
1981     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1982     C++ linking (needed for some HP-UX environments).
1984     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1985     (unused parameter) and in the pcre_printint() function (omitted "default"
1986     switch label when the default is to do nothing).
1988     15. Added some code to make it possible, when PCRE is compiled as a C++
1989     library, to replace subject pointers for pcre_exec() with a smart pointer
1990     class, thus making it possible to process discontinuous strings.
1992     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1993     much the same function. They were added by different people who were trying
1994     to make PCRE easy to compile on non-Unix systems. It has been suggested
1995     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1996     for compiling on Windows systems. I have therefore replaced it with
1997     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1998     defaults to "extern" for C or "extern C" for C++, which works fine on
1999     Unix-like systems. It is now possible to override the value of PCRE_DATA_
2000     SCOPE with something explicit in config.h. In addition:
2002     (a) pcreposix.h still had just "extern" instead of either of these macros;
2003     I have replaced it with PCRE_DATA_SCOPE.
2005     (b) Functions such as _pcre_xclass(), which are internal to the library,
2006     but external in the C sense, all had PCRE_EXPORT in their definitions.
2007     This is apparently wrong for the Windows case, so I have removed it.
2008     (It makes no difference on Unix-like systems.)
2010     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2011     of recursive calls to match(). This is different to MATCH_LIMIT because
2012     that limits the total number of calls to match(), not all of which increase
2013     the depth of recursion. Limiting the recursion depth limits the amount of
2014     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2015     when PCRE is compiled, and changed at run time. A patch from Google adds
2016     this functionality to the C++ interface.
2018     18. Changes to the handling of Unicode character properties:
2020     (a) Updated the table to Unicode 4.1.0.
2022     (b) Recognize characters that are not in the table as "Cn" (undefined).
2024     (c) I revised the way the table is implemented to a much improved format
2025     which includes recognition of ranges. It now supports the ranges that
2026     are defined in UnicodeData.txt, and it also amalgamates other
2027     characters into ranges. This has reduced the number of entries in the
2028     table from around 16,000 to around 3,000, thus reducing its size
2029     considerably. I realized I did not need to use a tree structure after
2030     all - a binary chop search is just as efficient. Having reduced the
2031     number of entries, I extended their size from 6 bytes to 8 bytes to
2032     allow for more data.
2034     (d) Added support for Unicode script names via properties such as \p{Han}.
2036     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2037     matching that character.
2039     20. When matching a repeated Unicode property with a minimum greater than zero,
2040     (for example \pL{2,}), PCRE could look past the end of the subject if it
2041     reached it while seeking the minimum number of characters. This could
2042     happen only if some of the characters were more than one byte long, because
2043     there is a check for at least the minimum number of bytes.
2045     21. Refactored the implementation of \p and \P so as to be more general, to
2046     allow for more different types of property in future. This has changed the
2047     compiled form incompatibly. Anybody with saved compiled patterns that use
2048     \p or \P will have to recompile them.
2050     22. Added "Any" and "L&" to the supported property types.
2052     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2053     but give a compile time error if the value is greater than 0xff.
2055     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2056     accidentally not being installed or uninstalled.
2058     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2059     made were to insert the current release number. This seemed silly, because
2060     it made things harder for people building PCRE on systems that don't run
2061     "configure". I have turned pcre.h into a distributed file, no longer built
2062     by "configure", with the version identification directly included. There is
2063     no longer a pcre.h.in file.
2065     However, this change necessitated a change to the pcre-config script as
2066     well. It is built from pcre-config.in, and one of the substitutions was the
2067     release number. I have updated configure.ac so that ./configure now finds
2068     the release number by grepping pcre.h.
2070     26. Added the ability to run the tests under valgrind.
2073 nigel 85 Version 6.4 05-Sep-05
2074     ---------------------
2076     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2077     "--" to be printed when multiple files were scanned, even when none of the
2078     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2079     consider it to be a bug, and have restored the previous behaviour.
2081     2. A couple of code tidies to get rid of compiler warnings.
2083     3. The pcretest program used to cheat by referring to symbols in the library
2084     whose names begin with _pcre_. These are internal symbols that are not
2085     really supposed to be visible externally, and in some environments it is
2086     possible to suppress them. The cheating is now confined to including
2087     certain files from the library's source, which is a bit cleaner.
2089     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2090     file's purpose clearer.
2092     5. Reorganized pcre_ucp_findchar().
2095 nigel 83 Version 6.3 15-Aug-05
2096     ---------------------
2098     1. The file libpcre.pc.in did not have general read permission in the tarball.
2100     2. There were some problems when building without C++ support:
2102     (a) If C++ support was not built, "make install" and "make test" still
2103     tried to test it.
2105     (b) There were problems when the value of CXX was explicitly set. Some
2106     changes have been made to try to fix these, and ...
2108     (c) --disable-cpp can now be used to explicitly disable C++ support.
2110     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2111     backslash in a target when C++ was disabled. This confuses some
2112     versions of "make", apparently. Using an intermediate variable solves
2113     this. (Same for CPP_LOBJ.)
2115     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2116     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2117     necessary on certain architectures.
2119     4. Added a setting of -export-symbols-regex to the link command to remove
2120     those symbols that are exported in the C sense, but actually are local
2121     within the library, and not documented. Their names all begin with
2122     "_pcre_". This is not a perfect job, because (a) we have to except some
2123     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2124     available (and never for static libraries). I have made a note to try to
2125     find a way round (a) in the future.
2128 nigel 81 Version 6.2 01-Aug-05
2129     ---------------------
2131     1. There was no test for integer overflow of quantifier values. A construction
2132     such as {1111111111111111} would give undefined results. What is worse, if
2133     a minimum quantifier for a parenthesized subpattern overflowed and became
2134     negative, the calculation of the memory size went wrong. This could have
2135     led to memory overwriting.
2137     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2139     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2140     operating environments where this matters.
2142     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2143     PCRE options from within the C++ wrapper.
2145     5. Named capturing subpatterns were not being correctly counted when a pattern
2146     was compiled. This caused two problems: (a) If there were more than 100
2147     such subpatterns, the calculation of the memory needed for the whole
2148     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2149     back references of the form \12, where the number was greater than 9, were
2150     not recognized as back references, even though there were sufficient
2151     previous subpatterns.
2153     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2154     versions of gcc, e.g. 2.95.4.
2157 nigel 79 Version 6.1 21-Jun-05
2158     ---------------------
2160     1. There was one reference to the variable "posix" in pcretest.c that was not
2161     surrounded by "#if !defined NOPOSIX".
2163     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2164     the cross-check on the old pcre_info() function, for the benefit of the
2165     cut-down version of PCRE that is currently imported into Exim.
2167     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2168     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2169     patterns that start (?i) but I don't think that matters. The use of (?i) is
2170     just an example; this all applies to the other options as well.
2172     4. Since libtool seems to echo the compile commands it is issuing, the output
2173     from "make" can be reduced a bit by putting "@" in front of each libtool
2174     compile command.
2176     5. Patch from the folks at Google for configure.in to be a bit more thorough
2177     in checking for a suitable C++ installation before trying to compile the
2178     C++ stuff. This should fix a reported problem when a compiler was present,
2179     but no suitable headers.
2181     6. The man pages all had just "PCRE" as their title. I have changed them to
2182     be the relevant file name. I have also arranged that these names are
2183     retained in the file doc/pcre.txt, which is a concatenation in text format
2184     of all the man pages except the little individual ones for each function.
2186     7. The NON-UNIX-USE file had not been updated for the different set of source
2187     files that come with release 6. I also added a few comments about the C++
2188     wrapper.
2191 nigel 77 Version 6.0 07-Jun-05
2192     ---------------------
2194     1. Some minor internal re-organization to help with my DFA experiments.
2196     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2197     didn't matter for the library itself when fully configured, but did matter
2198     when compiling without UCP support, or within Exim, where the ucp files are
2199     not imported.
2201     3. Refactoring of the library code to split up the various functions into
2202     different source modules. The addition of the new DFA matching code (see
2203     below) to a single monolithic source would have made it really too
2204     unwieldy, quite apart from causing all the code to be include in a
2205     statically linked application, when only some functions are used. This is
2206     relevant even without the DFA addition now that patterns can be compiled in
2207     one application and matched in another.
2209     The downside of splitting up is that there have to be some external
2210     functions and data tables that are used internally in different modules of
2211     the library but which are not part of the API. These have all had their
2212     names changed to start with "_pcre_" so that they are unlikely to clash
2213     with other external names.
2215     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2216     a different (DFA) algorithm. Although it is slower than the original
2217     function, it does have some advantages for certain types of matching
2218     problem.
2220     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2221     including restarting after a partial match.
2223     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2224     defined when compiling for Windows was sent to me. I have put it into the
2225     code, though I have no means of testing or verifying it.
2227     7. Added the pcre_refcount() auxiliary function.
2229     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2230     match before or at the first newline in the subject string. In pcretest,
2231     the /f option on a pattern can be used to set this.
2233     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2234     would behave wrongly. This has been present in PCRE since release 4.0.
2236     10. A number of changes to the pcregrep command:
2238     (a) Refactored how -x works; insert ^(...)$ instead of setting
2239     PCRE_ANCHORED and checking the length, in preparation for adding
2240     something similar for -w.
2242     (b) Added the -w (match as a word) option.
2244     (c) Refactored the way lines are read and buffered so as to have more
2245     than one at a time available.
2247     (d) Implemented a pcregrep test script.
2249     (e) Added the -M (multiline match) option. This allows patterns to match
2250     over several lines of the subject. The buffering ensures that at least
2251     8K, or the rest of the document (whichever is the shorter) is available
2252     for matching (and similarly the previous 8K for lookbehind assertions).
2254     (f) Changed the --help output so that it now says
2256     -w, --word-regex(p)
2258     instead of two lines, one with "regex" and the other with "regexp"
2259     because that confused at least one person since the short forms are the
2260     same. (This required a bit of code, as the output is generated
2261     automatically from a table. It wasn't just a text change.)
2263     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2264     option but starts with a hyphen. Could be a pattern or a path name
2265     starting with a hyphen, for instance.
2267     (h) "-" can be given as a file name to represent stdin.
2269     (i) When file names are being printed, "(standard input)" is used for
2270     the standard input, for compatibility with GNU grep. Previously
2271     "<stdin>" was used.
2273     (j) The option --label=xxx can be used to supply a name to be used for
2274     stdin when file names are being printed. There is no short form.
2276     (k) Re-factored the options decoding logic because we are going to add
2277     two more options that take data. Such options can now be given in four
2278     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2280     (l) Added the -A, -B, and -C options for requesting that lines of context
2281     around matches be printed.
2283     (m) Added the -L option to print the names of files that do not contain
2284     any matching lines, that is, the complement of -l.
2286     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2287     continue to scan other files.
2289     (o) The -s option was incorrectly implemented. For compatibility with other
2290     greps, it now suppresses the error message for a non-existent or non-
2291     accessible file (but not the return code). There is a new option called
2292     -q that suppresses the output of matching lines, which was what -s was
2293     previously doing.
2295     (p) Added --include and --exclude options to specify files for inclusion
2296     and exclusion when recursing.
2298     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2299     Hopefully, it now does.
2301     12. Missing cast in pcre_study().
2303     13. Added an "uninstall" target to the makefile.
2305     14. Replaced "extern" in the function prototypes in Makefile.in with
2306     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2307     world, but is set differently for Windows.
2309     15. Added a second compiling function called pcre_compile2(). The only
2310     difference is that it has an extra argument, which is a pointer to an
2311     integer error code. When there is a compile-time failure, this is set
2312     non-zero, in addition to the error test pointer being set to point to an
2313     error message. The new argument may be NULL if no error number is required
2314     (but then you may as well call pcre_compile(), which is now just a
2315     wrapper). This facility is provided because some applications need a
2316     numeric error indication, but it has also enabled me to tidy up the way
2317     compile-time errors are handled in the POSIX wrapper.
2319     16. Added VPATH=.libs to the makefile; this should help when building with one
2320     prefix path and installing with another. (Or so I'm told by someone who
2321     knows more about this stuff than I do.)
2323     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2324     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2325     match everything, including newlines. This is not POSIX-compatible, but
2326     somebody wanted the feature. From pcretest it can be activated by using
2327     both the P and the s flags.
2329     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2331     19. libpcre.pc was being incorrectly installed as executable.
2333     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2334     it now also looks for '\r' so that it will work unmodified on Windows.
2336     21. Added Google's contributed C++ wrapper to the distribution.
2338     22. Added some untidy missing memory free() calls in pcretest, to keep
2339     Electric Fence happy when testing.
2343 nigel 75 Version 5.0 13-Sep-04
2344     ---------------------
2346     1. Internal change: literal characters are no longer packed up into items
2347     containing multiple characters in a single byte-string. Each character
2348     is now matched using a separate opcode. However, there may be more than one
2349     byte in the character in UTF-8 mode.
2351     2. The pcre_callout_block structure has two new fields: pattern_position and
2352     next_item_length. These contain the offset in the pattern to the next match
2353     item, and its length, respectively.
2355     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2356     insertion of callouts before each pattern item. Added the /C option to
2357     pcretest to make use of this.
2359     4. On the advice of a Windows user, the lines
2361     #if defined(_WIN32) || defined(WIN32)
2362     _setmode( _fileno( stdout ), 0x8000 );
2363     #endif /* defined(_WIN32) || defined(WIN32) */
2365     have been added to the source of pcretest. This apparently does useful
2366     magic in relation to line terminators.
2368     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2369     for the benefit of those environments where the "b" makes a difference.
2371     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2372     to know about it. I have put a hack into configure.in that adds in code
2373     to set GCC=yes if CC=icc. This seems to end up at a point in the
2374     generated configure script that is early enough to affect the setting of
2375     compiler options, which is what is needed, but I have no means of testing
2376     whether it really works. (The user who reported this had patched the
2377     generated configure script, which of course I cannot do.)
2379     LATER: After change 22 below (new libtool files), the configure script
2380     seems to know about icc (and also ecc). Therefore, I have commented out
2381     this hack in configure.in.
2383     7. Added support for pkg-config (2 patches were sent in).
2385     8. Negated POSIX character classes that used a combination of internal tables
2386     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2387     [[:^ascii]]. Typically, they would match almost any characters. The other
2388     POSIX classes were not broken in this way.
2390     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2391     to find the match, as PCRE was deluded into thinking that the match had to
2392     start at the start point or following a newline. The same bug applied to
2393     patterns with negative forward assertions or any backward assertions
2394     preceding ".*" at the start, unless the pattern required a fixed first
2395     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2397     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2398     starting at the last subject character, bytes beyond the end of the subject
2399     string were read.
2401     11. Renamed the variable "class" as "classbits" to make life easier for C++
2402     users. (Previously there was a macro definition, but it apparently wasn't
2403     enough.)
2405     12. Added the new field "tables" to the extra data so that tables can be passed
2406     in at exec time, or the internal tables can be re-selected. This allows
2407     a compiled regex to be saved and re-used at a later time by a different
2408     program that might have everything at different addresses.
2410     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2411     -R library as well as a -L library.
2413     14. The debugging options of pcretest (-d on the command line or D on a
2414     pattern) showed incorrect output for anything following an extended class
2415     that contained multibyte characters and which was followed by a quantifier.
2417     15. Added optional support for general category Unicode character properties
2418     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2419     support. It adds about 90K to the size of the library. The meanings of the
2420     inbuilt class escapes such as \d and \s have NOT been changed.
2422     16. Updated pcredemo.c to include calls to free() to release the memory for the
2423     compiled pattern.
2425     17. The generated file chartables.c was being created in the source directory
2426     instead of in the building directory. This caused the build to fail if the
2427     source directory was different from the building directory, and was
2428     read-only.
2430     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2431     file. No doubt somebody will tell me if they don't make sense... Also added
2432     Dan Mooney's comments about building on OpenVMS.
2434     19. Added support for partial matching via the PCRE_PARTIAL option for
2435     pcre_exec() and the \P data escape in pcretest.
2437     20. Extended pcretest with 3 new pattern features:
2439     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2440     write the compiled pattern to the file whose name is "rest-of-line".
2441     This is a straight binary dump of the data, with the saved pointer to
2442     the character tables forced to be NULL. The study data, if any, is
2443     written too. After writing, pcretest reads a new pattern.
2445     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2446     compiled pattern from the given file. There must not be any
2447     occurrences of "<" in the file name (pretty unlikely); if there are,
2448     pcretest will instead treat the initial "<" as a pattern delimiter.
2449     After reading in the pattern, pcretest goes on to read data lines as
2450     usual.
2452     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2453     and 16-bit fields in a compiled pattern, to simulate a pattern that
2454     was compiled on a host of opposite endianness.
2456     21. The pcre-exec() function can now cope with patterns that were compiled on
2457     hosts of opposite endianness, with this restriction:
2459     As for any compiled expression that is saved and used later, the tables
2460     pointer field cannot be preserved; the extra_data field in the arguments
2461     to pcre_exec() should be used to pass in a tables address if a value
2462     other than the default internal tables were used at compile time.
2464     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2465     now diagnosed as an error. Previously, most of the time, a negative number
2466     would have been treated as zero, but if in addition "ovector" was passed as
2467     NULL, a crash could occur.
2469     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2470     new versions from the libtool 1.5 distribution (the last one is a copy of
2471     a file called libtool.m4). This seems to have fixed the need to patch
2472     "configure" to support Darwin 1.3 (which I used to do). However, I still
2473     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2474     workstation).
2476     24. Changed the PCRE licence to be the more standard "BSD" licence.
2479 nigel 73 Version 4.5 01-Dec-03
2480     ---------------------
2482     1. There has been some re-arrangement of the code for the match() function so
2483     that it can be compiled in a version that does not call itself recursively.
2484     Instead, it keeps those local variables that need separate instances for
2485     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2486     needs to "recurse". Keeping track of where control must go is done by means
2487     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2488     hide most of the details from the main code, and operates only if
2489     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2490     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2491     operating.
2493     To make it easier for callers to provide specially tailored get/free
2494     functions for this usage, two new functions, pcre_stack_malloc, and
2495     pcre_stack_free, are used. They are always called in strict stacking order,
2496     and the size of block requested is always the same.
2498     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2499     PCRE has been compiled to use the stack or the heap for recursion. The
2500     -C option of pcretest uses this to show which version is compiled.
2502     A new data escape \S, is added to pcretest; it causes the amounts of store
2503     obtained and freed by both kinds of malloc/free at match time to be added
2504     to the output.
2506     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2507     what's available on my current Linux desktop machine.
2509     3. When matching a UTF-8 string, the test for a valid string at the start has
2510     been extended. If start_offset is not zero, PCRE now checks that it points
2511     to a byte that is the start of a UTF-8 character. If not, it returns
2512     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2513     this is necessary because there may be backward assertions in the pattern.
2514     When matching the same subject several times, it may save resources to use
2515     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2517     4. The code for checking the validity of UTF-8 strings has been tightened so
2518     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2519     containing "overlong sequences".
2521     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2522     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2523     should have been "&", but it just so happened that all the cases this let
2524     through by mistake were picked up later in the function.
2526     6. I had used a variable called "isblank" - this is a C99 function, causing
2527     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2529     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2530     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2531     so the version is shown; (c) stop "make test" echoing "./RunTest".
2533     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2535     9. The prototype for memmove() for systems that don't have it was using
2536     size_t, but the inclusion of the header that defines size_t was later. I've
2537     moved the #includes for the C headers earlier to avoid this.
2539     10. Added some adjustments to the code to make it easier to compiler on certain
2540     special systems:
2542     (a) Some "const" qualifiers were missing.
2543     (b) Added the macro EXPORT before all exported functions; by default this
2544     is defined to be empty.
2545     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2546     that it reads its output file name as an argument instead of writing
2547     to the standard output and assuming this can be redirected.
2549     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2550     class containing characters with values greater than 255, PCRE compilation
2551     went into a loop.
2553     12. A recursive reference to a subpattern that was within another subpattern
2554     that had a minimum quantifier of zero caused PCRE to crash. For example,
2555     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2556     recursion. If the recursively-called subpattern itself had a zero repeat,
2557     that was OK.
2559     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2560     buffer into which it was copied (for escape processing) was still set at
2561     1024, so long lines caused crashes.
2563     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2564     "internal error: code overflow...". This applied to any character class
2565     that was followed by a possessive quantifier.
2567     15. Modified the Makefile to add libpcre.la as a prerequisite for
2568     libpcreposix.la because I was told this is needed for a parallel build to
2569     work.
2571     16. If a pattern that contained .* following optional items at the start was
2572     studied, the wrong optimizing data was generated, leading to matching
2573     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2574     matching string must start with a or b or c. The correct conclusion for
2575     this pattern is that a match can start with any character.
2578 nigel 71 Version 4.4 13-Aug-03
2579     ---------------------
2581     1. In UTF-8 mode, a character class containing characters with values between
2582     127 and 255 was not handled correctly if the compiled pattern was studied.
2583     In fixing this, I have also improved the studying algorithm for such
2584     classes (slightly).
2586     2. Three internal functions had redundant arguments passed to them. Removal
2587     might give a very teeny performance improvement.
2589     3. Documentation bug: the value of the capture_top field in a callout is *one
2590     more than* the number of the hightest numbered captured substring.
2592     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2593     in incorrectly linking with a previously installed version. They now link
2594     explicitly with libpcre.la.
2596     5. configure.in no longer needs to recognize Cygwin specially.
2598     6. A problem in pcre.in for Windows platforms is fixed.
2600     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2601     pcretest, it used to include the size of the study block as part of its
2602     output. Unfortunately, the structure contains a field that has a different
2603     size on different hardware architectures. This meant that the tests that
2604     showed this size failed. As the block is currently always of a fixed size,
2605     this information isn't actually particularly useful in pcretest output, so
2606     I have just removed it.
2608     8. Three pre-processor statements accidentally did not start in column 1.
2609     Sadly, there are *still* compilers around that complain, even though
2610     standard C has not required this for well over a decade. Sigh.
2612     9. In pcretest, the code for checking callouts passed small integers in the
2613     callout_data field, which is a void * field. However, some picky compilers
2614     complained about the casts involved for this on 64-bit systems. Now
2615     pcretest passes the address of the small integer instead, which should get
2616     rid of the warnings.
2618     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2619     both compile and run time, and gives an error if an invalid UTF-8 sequence
2620     is found. There is a option for disabling this check in cases where the
2621     string is known to be correct and/or the maximum performance is wanted.
2623     11. In response to a bug report, I changed one line in Makefile.in from
2625     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2626     to
2627     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2629     to look similar to other lines, but I have no way of telling whether this
2630     is the right thing to do, as I do not use Windows. No doubt I'll get told
2631     if it's wrong...
2634 nigel 69 Version 4.3 21-May-03
2635     ---------------------
2637     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2638     Makefile.
2640     2. Some refactoring to improve the quality of the code:
2642     (i) The utf8_table... variables are now declared "const".
2644     (ii) The code for \cx, which used the "case flipping" table to upper case
2645     lower case letters, now just substracts 32. This is ASCII-specific,
2646     but the whole concept of \cx is ASCII-specific, so it seems
2647     reasonable.
2649     (iii) PCRE was using its character types table to recognize decimal and
2650     hexadecimal digits in the pattern. This is silly, because it handles
2651     only 0-9, a-f, and A-F, but the character types table is locale-
2652     specific, which means strange things might happen. A private
2653     table is now used for this - though it costs 256 bytes, a table is
2654     much faster than multiple explicit tests. Of course, the standard
2655     character types table is still used for matching digits in subject
2656     strings against \d.
2658     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2659     ending in _t are). So I've renamed it as ESC_tee.
2661     3. The first argument for regexec() in the POSIX wrapper should have been
2662     defined as "const".
2664     4. Changed pcretest to use malloc() for its buffers so that they can be
2665     Electric Fenced for debugging.
2667     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2668     to read one or more bytes before the start of the subject string. Often this
2669     had no effect on PCRE's behaviour, but in some circumstances it could
2670     provoke a segmentation fault.
2672     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2673     to try to read one or more bytes before the start of the subject string.
2675     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2676     UTF-8 support could misbehave in various ways if the subject string
2677     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2678     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2679     back over UTF-8 characters.)
2682 nigel 67 Version 4.2 14-Apr-03
2683     ---------------------
2685     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2687     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2688     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2689     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2690     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2691     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2692     and BUILD_EXEEXT
2693     Note: automatic setting of the BUILD variables is not yet working
2694     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2695     compile-time but not at link-time
2696     [LINK]: use for linking executables only
2697     make different versions for Windows and non-Windows
2698     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2699     libraries
2700     [LINK_FOR_BUILD]: new variable
2701     [OBJEXT]: use throughout
2702     [EXEEXT]: use throughout
2703     <winshared>: new target
2704     <wininstall>: new target
2705     <dftables.o>: use native compiler
2706     <dftables>: use native linker
2707     <install>: handle Windows platform correctly
2708     <clean>: ditto
2709     <check>: ditto
2710     copy DLL to top builddir before testing
2712     As part of these changes, -no-undefined was removed again. This was reported
2713     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2714     in any case.
2716     3. Some tidies to get rid of compiler warnings:
2718     . In the match_data structure, match_limit was an unsigned long int, whereas
2719     match_call_count was an int. I've made them both unsigned long ints.
2721     . In pcretest the fact that a const uschar * doesn't automatically cast to
2722     a void * provoked a warning.
2724     . Turning on some more compiler warnings threw up some "shadow" variables
2725     and a few more missing casts.
2727     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2728     option, a class that contained a single character with a value between 128
2729     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2731     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2732     option, a class that contained several characters, but with at least one
2733     whose value was between 128 and 255 caused PCRE to crash.
2736 nigel 65 Version 4.1 12-Mar-03
2737     ---------------------
2738 nigel 63
2739 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2740     needed, and a string in dftables.c that was longer than standard compilers are
2741     required to support.
2743     2. Compiling with Sun's compiler found a few more places where the code could
2744     be tidied up in order to avoid warnings.
2746     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2747     first of these names is deprecated in the latest Autoconf in favour of the name
2748     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2749     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2750     analogy I have changed it to CFLAGS_FOR_BUILD.
2752     4. Added -no-undefined to the linking command in the Makefile, because this is
2753     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2754     linking step for the pcreposix library.
2756     5. PCRE was failing to diagnose the case of two named groups with the same
2757     name.
2759     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2760     literal character that is needed in the subject for a match, and scans along to
2761     ensure that it is present before embarking on the full matching process. This
2762     saves time in cases of nested unlimited repeats that are never going to match.
2763     Problem: the scan can take a lot of time if the subject is very long (e.g.
2764     megabytes), thus penalizing straightforward matches. It is now done only if the
2765     amount of subject to be scanned is less than 1000 bytes.
2767     7. A lesser problem with the same optimization is that it was recording the
2768     first character of an anchored pattern as "needed", thus provoking a search
2769     right along the subject, even when the first match of the pattern was going to
2770     fail. The "needed" character is now not set for anchored patterns, unless it
2771     follows something in the pattern that is of non-fixed length. Thus, it still
2772     fulfils its original purpose of finding quick non-matches in cases of nested
2773     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2776     Version 4.0 17-Feb-03
2777     ---------------------
2779 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2780     extended to the end of string, PCRE compiled incorrect data. This could lead to
2781     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2783     2. Moved to autoconf 2.53 and libtool 1.4.2.
2785     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2786     the special perltest8 script is no longer needed - all the tests can be run
2787     from a single perltest script.
2789     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2790     by \s. It has now been removed in PCRE. This means it isn't recognized as
2791     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2792     class [:space:] *does* include VT, thereby creating a mess.
2794     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2795     space and tab.
2797     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2798     its new features into the main test script, reducing the number of scripts.
2800     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2801     were backward compatible, and made the (?i) apply to the whole pattern, as if
2802     /i were given. Now it behaves more logically, and applies the option setting
2803     only to what follows. PCRE has been changed to follow suit. However, if it
2804     finds options settings right at the start of the pattern, it extracts them into
2805     the global options, as before. Thus, they show up in the info data.
2807     8. Added support for the \Q...\E escape sequence. Characters in between are
2808     treated as literals. This is slightly different from Perl in that $ and @ are
2809     also handled as literals inside the quotes. In Perl, they will cause variable
2810     interpolation. Note the following examples:
2812     Pattern PCRE matches Perl matches
2814     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2815     \Qabc\$xyz\E abc\$xyz abc\$xyz
2816     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2818     For compatibility with Perl, \Q...\E sequences are recognized inside character
2819     classes as well as outside them.
2821     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2822     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2823     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2824     signed/unsigned warnings.
2826     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2827     option for pcretest, so I've replaced it by a simple function that does just
2828     that job.
2830     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2831     "pcregrep -".
2833     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2834     Java package. This provides some syntactic sugar for simple cases of what my
2835     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2836     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2837     item, you can use this simplified notation. Note that only makes sense with
2838     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2839     greediness, whatever the setting of the PCRE_UNGREEDY option.
2841     13. A change of greediness default within a pattern was not taking effect at
2842     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2843     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2844     was abstracted outside.
2846     14. PCRE now supports the \G assertion. It is true when the current matching
2847     position is at the start point of the match. This differs from \A when the
2848     starting offset is non-zero. Used with the /g option of pcretest (or similar
2849     code), it works in the same way as it does for Perl's /g option. If all
2850     alternatives of a regex begin with \G, the expression is anchored to the start
2851     match position, and the "anchored" flag is set in the compiled expression.
2853     15. Some bugs concerning the handling of certain option changes within patterns
2854     have been fixed. These applied to options other than (?ims). For example,
2855     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2856     been the other way round. Some of this was related to change 7 above.
2858     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2859     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2860     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2861     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2863     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2864     mode. Unlike ".", it always matches newline, whatever the setting of
2865     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2866     assertions. Perl allows it, but it doesn't (in general) work because it can't
2867     calculate the length of the lookbehind. At least, that's the case for Perl
2868     5.8.0 - I've been told they are going to document that it doesn't work in
2869     future.
2871     18. Added an error diagnosis for escapes that PCRE does not support: these are
2872     \L, \l, \N, \P, \p, \U, \u, and \X.
2874     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2875     reading past the end of the pattern in cases such as /[abcd/.
2877     20. PCRE was getting more memory than necessary for patterns with classes that
2878     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2880     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2881     compiling PCRE for use with Virtual Pascal.
2883     22. Small fix to the Makefile to make it work properly if the build is done
2884     outside the source tree.
2886     23. Added a new extension: a condition to go with recursion. If a conditional
2887     subpattern starts with (?(R) the "true" branch is used if recursion has
2888     happened, whereas the "false" branch is used only at the top level.
2890     24. When there was a very long string of literal characters (over 255 bytes
2891     without UTF support, over 250 bytes with UTF support), the computation of how
2892     much memory was required could be incorrect, leading to segfaults or other
2893     strange effects.
2895     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2896     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2897     there was a subsequent back reference to those brackets. This meant that, for
2898     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2899     possible to check for precisely this case. All we can do is abandon the
2900     optimization if .* occurs inside capturing brackets when there are any back
2901     references whatsoever. (See below for a better fix that came later.)
2903     26. The handling of the optimization for finding the first character of a
2904     non-anchored pattern, and for finding a character that is required later in the
2905     match were failing in some cases. This didn't break the matching; it just
2906     failed to optimize when it could. The way this is done has been re-implemented.
2908     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2910     28. Added a new feature that provides some of the functionality that Perl
2911     provides with (?{...}). The facility is termed a "callout". The way it is done
2912     in PCRE is for the caller to provide an optional function, by setting
2913     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2914     global variable. By default it is unset, which disables all calling out. To get
2915     the function called, the regex must include (?C) at appropriate points. This
2916     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2917     This provides a means of identifying different callout points. When PCRE
2918     reaches such a point in the regex, if pcre_callout has been set, the external
2919     function is called. It is provided with data in a structure called
2920     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2921     matching continues; if it returns a non-zero value, the match at the current
2922     point fails. However, backtracking will occur if possible. [This was changed
2923     later and other features added - see item 49 below.]
2925     29. pcretest is upgraded to test the callout functionality. It provides a
2926     callout function that displays information. By default, it shows the start of
2927     the match and the current position in the text. There are some new data escapes
2928     to vary what happens:
2930     \C+ in addition, show current contents of captured substrings
2931     \C- do not supply a callout function
2932     \C!n return 1 when callout number n is reached
2933     \C!n!m return 1 when callout number n is reached for the mth time
2935     30. If pcregrep was called with the -l option and just a single file name, it
2936     output "<stdin>" if a match was found, instead of the file name.
2938     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2939     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2940     pcre_exec(). This saves a malloc/free per call. The default value of
2941     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2942     when configuring.
2944     32. The default maximum size of a compiled pattern is 64K. There have been a
2945     few cases of people hitting this limit. The code now uses macros to handle the
2946     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2947     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2948     configuring. Tests 2 and 5 work only with 2-byte links because they output
2949     debugging information about compiled patterns.
2951     33. Internal code re-arrangements:
2953     (a) Moved the debugging function for printing out a compiled regex into
2954     its own source file (printint.c) and used #include to pull it into
2955     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2956     separate copies.
2958     (b) Defined the list of op-code names for debugging as a macro in
2959     internal.h so that it is next to the definition of the opcodes.
2961     (c) Defined a table of op-code lengths for simpler skipping along compiled
2962     code. This is again a macro in internal.h so that it is next to the
2963     definition of the opcodes.
2965     34. Added support for recursive calls to individual subpatterns, along the
2966     lines of Robin Houston's patch (but implemented somewhat differently).
2968     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2969     allow it to read and process whole directories in Win32. This code was
2970     contributed by Lionel Fourquaux; it has not been tested by me.
2972     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2973     used to name a group. Names consist of alphanumerics and underscores, and must
2974     be unique. Back references use the syntax (?P=name) and recursive calls use
2975     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2976     numbers. The function pcre_fullinfo() can be used after compilation to extract
2977     a name/number map. There are three relevant calls:
2979     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2980     PCRE_INFO_NAMECOUNT yields the number of entries
2981     PCRE_INFO_NAMETABLE yields a pointer to the map.
2983     The map is a vector of fixed-size entries. The size of each entry depends on
2984     the length of the longest name used. The first two bytes of each entry are the
2985     group number, most significant byte first. There follows the corresponding
2986     name, zero terminated. The names are in alphabetical order.
2988     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2989     case instead of 255. Making it the same both with and without UTF-8 support
2990     means that the same test output works with both.
2992     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2993     calling malloc() with a zero argument.
2995     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2996     optimization. I've improved things by keeping a bitmap of backreferences with
2997     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2998     fact referenced, the optimization can be applied. It is unlikely that a
2999     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3000     the match to follow \n) will appear inside brackets with a number greater than
3001     31, but if it does, any back reference > 31 suppresses the optimization.
3003     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3004     of disabling numbered capturing parentheses. Any opening parenthesis that is
3005     not followed by ? behaves as if it were followed by ?: but named parentheses
3006     can still be used for capturing (and they will acquire numbers in the usual
3007     way).
3009     41. Redesigned the return codes from the match() function into yes/no/error so
3010     that errors can be passed back from deep inside the nested calls. A malloc
3011     failure while inside a recursive subpattern call now causes the
3012     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3014     42. It is now possible to set a limit on the number of times the match()
3015     function is called in a call to pcre_exec(). This facility makes it possible to
3016     limit the amount of recursion and backtracking, though not in a directly
3017     obvious way, because the match() function is used in a number of different
3018     circumstances. The count starts from zero for each position in the subject
3019     string (for non-anchored patterns). The default limit is, for compatibility, a
3020     large number, namely 10 000 000. You can change this in two ways:
3022     (a) When configuring PCRE before making, you can use --with-match-limit=n
3023     to set a default value for the compiled library.
3025     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3026     a different value is set. See 45 below.
3028     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3030     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3031     of things that can be changed at compile time. The first argument specifies
3032     what is wanted and the second points to where the information is to be placed.
3033     The current list of available information is:
3037     The output is an integer that is set to one if UTF-8 support is available;
3038     otherwise it is set to zero.
3042     The output is an integer that it set to the value of the code that is used for
3043     newline. It is either LF (10) or CR (13).
3047     The output is an integer that contains the number of bytes used for internal
3048     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3052     The output is an integer that contains the threshold above which the POSIX
3053     interface uses malloc() for output vectors. See item 31 above.
3057     The output is an unsigned integer that contains the default limit of the number
3058     of match() calls in a pcre_exec() execution. See 42 above.
3060     44. pcretest has been upgraded by the addition of the -C option. This causes it
3061     to extract all the available output from the new pcre_config() function, and to
3062     output it. The program then exits immediately.
3064     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3065     order to support additional features. One way would have been to define
3066     pcre_exec2() (for example) with extra arguments, but this would not have been
3067     extensible, and would also have required all calls to the original function to
3068     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3069     is used for passing in "extra" data from pcre_study().
3071     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3072     contains the following fields:
3074     flags a bitmap indicating which of the following fields are set
3075     study_data opaque data from pcre_study()
3076     match_limit a way of specifying a limit on match() calls for a specific
3077     call to pcre_exec()
3078     callout_data data for callouts (see 49 below)
3080     The flag bits are also defined in pcre.h, and are
3086     The pcre_study() function now returns one of these new pcre_extra blocks, with
3087     the actual study data pointed to by the study_data field, and the
3088     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3089     before. That is, this change is entirely upwards-compatible and requires no
3090     change to existing code.
3092     If you want to pass in additional data to pcre_exec(), you can either place it
3093     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3094     block.
3096     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3097     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3098     times with different match limits, until it finds the minimum value needed for
3099     pcre_exec() to complete. The value is then output. This can be instructive; for
3100     most simple matches the number is quite small, but for pathological cases it
3101     gets very large very quickly.
3103     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3104     returns the size of the data block pointed to by the study_data field in a
3105     pcre_extra block, that is, the value that was passed as the argument to
3106     pcre_malloc() when PCRE was getting memory in which to place the information
3107     created by pcre_study(). The fourth argument should point to a size_t variable.
3108     pcretest has been extended so that this information is shown after a successful
3109     pcre_study() call when information about the compiled regex is being displayed.
3111     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3112     because what follows is always an absolute path. (Later: it turns out that this
3113     is more than cosmetic for MinGW, because it doesn't like empty path
3114     components.)
3116     49. Some changes have been made to the callout feature (see 28 above):
3118     (i) A callout function now has three choices for what it returns:
3120     0 => success, carry on matching
3121     > 0 => failure at this point, but backtrack if possible
3122     < 0 => serious error, return this value from pcre_exec()
3124     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3125     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3126     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3127     use by callout functions. It will never be used by PCRE itself.
3129     (ii) The pcre_extra structure (see 45 above) has a void * field called
3130     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3131     pcre_callout_block structure has a field of the same name. The contents of
3132     the field passed in the pcre_extra structure are passed to the callout
3133     function in the corresponding field in the callout block. This makes it
3134     easier to use the same callout-containing regex from multiple threads. For
3135     testing, the pcretest program has a new data escape
3137     \C*n pass the number n (may be negative) as callout_data
3139     If the callout function in pcretest receives a non-zero value as
3140     callout_data, it returns that value.
3142     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3143     there were some redundant $(CFLAGS) in commands that are now specified as
3144     $(LINK), which already includes $(CFLAGS).
3146     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3147     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3148     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3149     one-byte characters throughout. Note that case-insensitive matching applies
3150     only to characters whose values are less than 256. PCRE doesn't support the
3151     notion of cases for higher-valued characters.
3153     (i) A character class whose characters are all within 0-255 is handled as
3154     a bit map, and the map is inverted for negative classes. Previously, a
3155     character > 255 always failed to match such a class; however it should
3156     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3158     (ii) A negated character class with a single character < 255 is coded as
3159     "not this character" (OP_NOT). This wasn't working properly when the test
3160     character was multibyte, either singly or repeated.
3162     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3163     mode, for example: \x{100}{2,3}.
3165     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3166     singly or repeated) now correctly test multibyte characters. However,
3167     PCRE doesn't recognize any characters with values greater than 255 as
3168     digits, spaces, or word characters. Such characters always match \D, \S,
3169     and \W, and never match \d, \s, or \w.
3171     (v) Classes may now contain characters and character ranges with values
3172     greater than 255. For example: [ab\x{100}-\x{400}].
3174     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3175     PCRE in UTF-8 mode.
3177     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3178     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3179     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3180     value.)
3182     53. The single man page has become too large. I have therefore split it up into
3183     a number of separate man pages. These also give rise to individual HTML pages;
3184     these are now put in a separate directory, and there is an index.html page that
3185     lists them all. Some hyperlinking between the pages has been installed.
3187     54. Added convenience functions for handling named capturing parentheses.
3189     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3190     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3191     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3192     are faulted.
3194     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3195     calling configure. These values are used when compiling the dftables.c program
3196     which is run to generate the source of the default character tables. They
3197     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3198     you will need to set these values.
3200     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3203     Version 3.9 02-Jan-02
3204 nigel 61 ---------------------
3206     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3208     2. If --disable-static was given, the building process failed when trying to
3209     build pcretest and pcregrep. (For some reason it was using libtool to compile
3210     them, which is not right, as they aren't part of the library.)
3213 nigel 59 Version 3.8 18-Dec-01
3214     ---------------------
3216     1. The experimental UTF-8 code was completely screwed up. It was packing the
3217     bytes in the wrong order. How dumb can you get?
3220 nigel 57 Version 3.7 29-Oct-01
3221     ---------------------
3223     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3224     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3225     this didn't happen under Solaris 8, where I normally test things.
3227 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3228     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3229     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3230     this fix an hour or so after the initial 3.7 release.)
3231 nigel 57
3232 nigel 59
3233 nigel 55 Version 3.6 23-Oct-01
3234     ---------------------
3236     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3237     offsets passed as NULL with zero offset count.
3239     2. The config.guess and config.sub files had not been updated when I moved to
3240     the latest autoconf.
3243 nigel 53 Version 3.5 15-Aug-01
3244     ---------------------
3245 nigel 5
3246 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3247     had been forgotten.
3249     2. By using declared but undefined structures, we can avoid using "void"
3250     definitions in pcre.h while keeping the internal definitions of the structures
3251     private.
3253     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3254     user point of view, this means that both static and shared libraries are built
3255     by default, but this can be individually controlled. More of the work of
3256     handling this static/shared cases is now inside libtool instead of PCRE's make
3257     file.
3259     4. The pcretest utility is now installed along with pcregrep because it is
3260     useful for users (to test regexs) and by doing this, it automatically gets
3261     relinked by libtool. The documentation has been turned into a man page, so
3262     there are now .1, .txt, and .html versions in /doc.
3264     5. Upgrades to pcregrep:
3265     (i) Added long-form option names like gnu grep.
3266     (ii) Added --help to list all options with an explanatory phrase.
3267     (iii) Added -r, --recursive to recurse into sub-directories.
3268     (iv) Added -f, --file to read patterns from a file.
3270     6. pcre_exec() was referring to its "code" argument before testing that
3271     argument for NULL (and giving an error if it was NULL).
3273     7. Upgraded Makefile.in to allow for compiling in a different directory from
3274     the source directory.
3276     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3277     options bits, the pointer it was passed was to an int instead of to an unsigned
3278     long int. This mattered only on 64-bit systems.
3280     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3281     generated) instead of pcre.in, which it its source. Also made the same change
3282     in several of the .c files.
3284     10. A new release of gcc defines printf() as a macro, which broke pcretest
3285     because it had an ifdef in the middle of a string argument for printf(). Fixed
3286     by using separate calls to printf().
3288     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3289     script, to force use of CR or LF instead of \n in the source. On non-Unix
3290     systems, the value can be set in config.h.
3292     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3293     absolute limit. Changed the text of the error message to make this clear, and
3294     likewise updated the man page.
3296     13. The limit of 99 on the number of capturing subpatterns has been removed.
3297     The new limit is 65535, which I hope will not be a "real" limit.
3300 nigel 51 Version 3.4 22-Aug-00
3301     ---------------------
3303     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3305     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3308 nigel 49 Version 3.3 01-Aug-00
3309     ---------------------
3311     1. If an octal character was given, but the value was greater than \377, it
3312     was not getting masked to the least significant bits, as documented. This could
3313     lead to crashes in some systems.
3315     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3316     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3318     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3319     These just pass their arguments on to (pcre_free)(), but they are provided
3320     because some uses of PCRE bind it to non-C systems that can call its functions,
3321     but cannot call free() or pcre_free() directly.
3323     4. Add "make test" as a synonym for "make check". Corrected some comments in
3324     the Makefile.
3326     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3327     Makefile.
3329     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3330     command called pgrep for grepping around the active processes.
3332     7. Added the beginnings of support for UTF-8 character strings.
3334     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3335     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3336     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3337     out for the ar command.)
3340 nigel 47 Version 3.2 12-May-00
3341     ---------------------
3343     This is purely a bug fixing release.
3345     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3346     of ZA. This was just one example of several cases that could provoke this bug,
3347     which was introduced by change 9 of version 2.00. The code for breaking
3348     infinite loops after an iteration that matches an empty string was't working
3349     correctly.
3351     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3352     when matched against abbab (for example). After matching an empty string, it
3353     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3354     caused it to match further down the string than it should.
3356     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3357     was there because it doesn't seem to be needed, and it causes trouble on some
3358     systems, as it is not a Standard C header. It has been removed.
3360     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3361     were reported on the Macintosh. The changes were from
3363     while ((c = *(++ptr)) != 0 && c != '\n');
3364     to
3365     while ((c = *(++ptr)) != 0 && c != '\n') ;
3367     Totally extraordinary, but if that's what it takes...
3369     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3370     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3371     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3372     assumes the way PCRE uses memmove() (always moving upwards).
3374     6. PCRE is being used in one environment where strchr() is not available. There
3375     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3376     faster code anyway.
3379 nigel 45 Version 3.1 09-Feb-00
3380     ---------------------
3382     The only change in this release is the fixing of some bugs in Makefile.in for
3383     the "install" target:
3385     (1) It was failing to install pcreposix.h.
3387     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3390 nigel 43 Version 3.0 01-Feb-00
3391     ---------------------
3392 nigel 41
3393     1. Add support for the /+ modifier to perltest (to output $` like it does in
3394     pcretest).
3396     2. Add support for the /g modifier to perltest.
3398     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3399     matches null strings.
3401     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3402     pattern. Perl treats empty patterns specially - it reuses the most recent
3403     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3404     effect.
3406     5. The POSIX interface was broken in that it was just handing over the POSIX
3407     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3408     required a bigger vector, with some working space on the end. This means that
3409     the POSIX wrapper now has to get and free some memory, and copy the results.
3411 nigel 43 6. Added some simple autoconf support, placing the test data and the
3412     documentation in separate directories, re-organizing some of the
3413     information files, and making it build pcre-config (a GNU standard). Also added
3414     libtool support for building PCRE as a shared library, which is now the
3415     default.
3416 nigel 41
3417 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3418     09 are not valid octal constants. Single digits will be used for minor values
3419     less than 10.
3421     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3422     existing programs that set these in the POSIX interface can use PCRE without
3423     modification.
3425     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3426     return all that pcre_info() returns, plus additional data. The pcre_info()
3427     function is retained for compatibility, but is considered to be obsolete.
3429     10. Added experimental recursion feature (?R) to handle one common case that
3430     Perl 5.6 will be able to do with (?p{...}).
3432     11. Added support for POSIX character classes like [:alpha:], which Perl is
3433     adopting.
3436 nigel 39 Version 2.08 31-Aug-99
3437     ----------------------
3439     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3440     trying to match at the startoffset position, but instead was moving forward to
3441     the next newline as if a previous match had failed.
3443     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3444     and could get into a loop if a null string was matched other than at the start
3445     of the subject.
3447     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3448     be distinguished at compile time, and for completeness also added PCRE_DATE.
3450     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3451     in GnuWin32 environments.
3454 nigel 37 Version 2.07 29-Jul-99
3455     ----------------------
3457     1. The documentation is now supplied in plain text form and HTML as well as in
3458     the form of man page sources.
3460     2. C++ compilers don't like assigning (void *) values to other pointer types.
3461     In particular this affects malloc(). Although there is no problem in Standard
3462     C, I've put in casts to keep C++ compilers happy.
3464     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3465     should be (const char *).
3467     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3468     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3469     However, I haven't made this a standard facility. The documentation doesn't
3470     mention it, and the Makefile doesn't support it.
3472     5. The Makefile now contains an "install" target, with editable destinations at
3473     the top of the file. The pcretest program is not installed.
3475     6. pgrep -V now gives the PCRE version number and date.
3477     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3478     causing the entire string to be ignored, instead of just the last character.
3480     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3481     non-matching string, it can take a very, very long time, even for strings of
3482     quite modest length, because of the nested recursion. PCRE now does better in
3483     some of these cases. It does this by remembering the last required literal
3484     character in the pattern, and pre-searching the subject to ensure it is present
3485     before running the real match. In other words, it applies a heuristic to detect
3486     some types of certain failure quickly, and in the above example, if presented
3487     with a string that has no trailing " it gives "no match" very quickly.
3489     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3490     other alternatives are tried instead.
3493 nigel 35 Version 2.06 09-Jun-99
3494     ----------------------
3496     1. Change pcretest's output for amount of store used to show just the code
3497     space, because the remainder (the data block) varies in size between 32-bit and
3498     64-bit systems.
3500     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3501     start matching at. This allows lookbehinds to work when searching for multiple
3502     occurrences in a string.
3504     3. Added additional options to pcretest for testing multiple occurrences:
3506     /+ outputs the rest of the string that follows a match
3507     /g loops for multiple occurrences, using the new startoffset argument
3508     /G loops for multiple occurrences by passing an incremented pointer
3510     4. PCRE wasn't doing the "first character" optimization for patterns starting
3511     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3512     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3513     the letter 'x'. On long subject strings, this gives a significant speed-up.
3516 nigel 33 Version 2.05 21-Apr-99
3517     ----------------------
3519     1. Changed the type of magic_number from int to long int so that it works
3520     properly on 16-bit systems.
3522     2. Fixed a bug which caused patterns starting with .* not to work correctly
3523     when the subject string contained newline characters. PCRE was assuming
3524     anchoring for such patterns in all cases, which is not correct because .* will
3525     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3526     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3527     must be retried after every newline in the subject.
3530 nigel 31 Version 2.04 18-Feb-99
3531     ----------------------
3533     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3534     computation of the store needed to hold the pattern was incorrect (too large).
3535     If such patterns were nested a few deep, this could multiply and become a real
3536     problem.
3538     2. Added /M option to pcretest to show the memory requirement of a specific
3539     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3541     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3542     compiled in such a way that the backtracking after subsequent failure was
3543     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3544     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3547 nigel 29 Version 2.03 02-Feb-99
3548     ----------------------
3550     1. Fixed typo and small mistake in man page.
3552 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3553     LICENCE file containing the conditions.
3554 nigel 29
3555     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3556     Perl, that is the internal \ allows the delimiter to be included in the
3557     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3558     the final delimiter, add \ to the end of the pattern (to test the error).
3560     4. Added the convenience functions for extracting substrings after a successful
3561     match. Updated pcretest to make it able to test these functions.
3564 nigel 27 Version 2.02 14-Jan-99
3565     ----------------------
3567     1. Initialized the working variables associated with each extraction so that
3568     their saving and restoring doesn't refer to uninitialized store.
3570     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3571     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3572     fix the problem.
3574     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3575     calls, and wasn't printing the correct value for compiling calls. Increased the
3576     default value of LOOPREPEAT, and the number of significant figures in the
3577     times.
3579     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3581     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3582     a building problem on Windows NT with a FAT file system.
3585 nigel 25 Version 2.01 21-Oct-98
3586     ----------------------
3588     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3589     to character tables built by pcre_maketables() in the current locale. If NULL
3590     is passed, the default tables are used.
3593 nigel 23 Version 2.00 24-Sep-98
3594 nigel 21 ----------------------
3596 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3597     it any more.
3599     2. Allow quantification of (?>) groups, and make it work correctly.
3601     3. The first character computation wasn't working for (?>) groups.
3603     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3604     end of the subject) and add 5.005's \z, which really does match only at the
3605     very end of the subject.
3607     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3609     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3610     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3611     localized options. All options to pcre_study() were also removed.
3613     7. Add other new features from 5.005:
3615     $(?<= positive lookbehind
3616     $(?<! negative lookbehind
3617     (?imsx-imsx) added the unsetting capability
3618     such a setting is global if at outer level; local otherwise
3619     (?imsx-imsx:) non-capturing groups with option setting
3620     (?(cond)re|re) conditional pattern matching
3622     A backreference to itself in a repeated group matches the previous
3623     captured string.
3625     8. General tidying up of studying (both automatic and via "study")
3626     consequential on the addition of new assertions.
3628     9. As in 5.005, unlimited repeated groups that could match an empty substring
3629     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3630     runtime if any iteration does actually match an empty substring.
3632     10. Include the RunTest script in the distribution.
3634     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3635     discrepancies, some of which were old and were also with respect to 5.004. They
3636     have now been fixed.
3639     Version 1.09 28-Apr-98
3640     ----------------------
3642 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3643     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3644     program crashes, or just wrong answers. This did not apply to negated classes
3645     containing more than one character, or to minima other than one.
3648 nigel 19 Version 1.08 27-Mar-98
3649     ----------------------
3651     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3653     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3654     latter must appear before anything that relies on it in the pattern.
3657 nigel 17 Version 1.07 16-Feb-98
3658     ----------------------
3660     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3661     repeat of a potentially empty string).
3664 nigel 15 Version 1.06 23-Jan-98
3665     ----------------------
3667     1. Added Markus Oberhumer's little patches for C++.
3669     2. Literal strings longer than 255 characters were broken.
3672 nigel 13 Version 1.05 23-Dec-97
3673     ----------------------
3675     1. Negated character classes containing more than one character were failing if
3676     PCRE_CASELESS was set at run time.
3679 nigel 11 Version 1.04 19-Dec-97
3680     ----------------------
3682     1. Corrected the man page, where some "const" qualifiers had been omitted.
3684     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3685     input syntax.
3687     3. Fixed memory leak which occurred when a regex with back references was
3688     matched with an offsets vector that wasn't big enough. The temporary memory
3689     that is used in this case wasn't being freed if the match failed.
3691     4. Tidied pcretest to ensure it frees memory that it gets.
3693     5. Temporary memory was being obtained in the case where the passed offsets
3694     vector was exactly big enough.
3696     6. Corrected definition of offsetof() from change 5 below.
3698     7. I had screwed up change 6 below and broken the rules for the use of
3699     setjmp(). Now fixed.
3702 nigel 9 Version 1.03 18-Dec-97
3703     ----------------------
3705     1. A erroneous regex with a missing opening parenthesis was correctly
3706     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3707     on some systems.
3709     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3710     it was reported that one broken compiler failed on the former because "code" is
3711     also an independent variable.
3713     3. The erroneous regex a[]b caused an array overrun reference.
3715     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3716     fail on data ending with that character. (It was going on too far, and checking
3717     the next character, typically a binary zero.) This was specific to the
3718     optimized code for single-character negative classes.
3720     5. Added a contributed patch from the TIN world which does the following:
3722     + Add an undef for memmove, in case the the system defines a macro for it.
3724     + Add a definition of offsetof(), in case there isn't one. (I don't know
3725     the reason behind this - offsetof() is part of the ANSI standard - but
3726     it does no harm).
3728     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3729     most of the places where whitespace preceded '#'. I have given up and
3730     allowed the remaining 2 cases to be at the margin.
3732     + Rename some variables in pcre to eliminate shadowing. This seems very
3733     pedantic, but does no harm, of course.
3735     6. Moved the call to setjmp() into its own function, to get rid of warnings
3736     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3738     7. Constructs such as \d{8,} were compiling into the equivalent of
3739 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3740 nigel 9 outcome, but in this particular case used more store than had been allocated,
3741     which caused the bug to be discovered because it threw up an internal error.
3743     8. The debugging code in both pcre and pcretest for outputting the compiled
3744     form of a regex was going wrong in the case of back references followed by
3745     curly-bracketed repeats.
3748 nigel 7 Version 1.02 12-Dec-97
3749     ----------------------
3751     1. Typos in pcre.3 and comments in the source fixed.
3753     2. Applied a contributed patch to get rid of places where it used to remove
3754     'const' from variables, and fixed some signed/unsigned and uninitialized
3755     variable warnings.
3757     3. Added the "runtest" target to Makefile.
3759     4. Set default compiler flag to -O2 rather than just -O.
3762 nigel 5 Version 1.01 19-Nov-97
3763     ----------------------
3765     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3766     like /([ab]*)*/, that is, for classes with more than one character in them.
3768     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3769     as /((?>a*))*/ (a PCRE_EXTRA facility).
3772     Version 1.00 18-Nov-97
3773     ----------------------
3775     1. Added compile-time macros to support systems such as SunOS4 which don't have
3776     memmove() or strerror() but have other things that can be used instead.
3778     2. Arranged that "make clean" removes the executables.
3781 nigel 3 Version 0.99 27-Oct-97