/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log


Revision 529 - (hide annotations) (download)
Mon May 31 17:28:08 2010 UTC (3 years, 10 months ago) by ph10
File size: 187962 byte(s)
Fix crash for property test in non-UTF-8 mode.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 513 Version 8.10 03 May-2010
5 ph10 510 ------------------------
6    
7 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8 ph10 510 THEN.
9    
10 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
11 ph10 510
12 ph10 513 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     causes the error). The code is unchanged, but I tidied the documentation.
15    
16     4. Inside a character class, PCRE always treated \R and \X as literals,
17     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 514
20     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 515
23     6. When compiling pcregrep with newer versions of gcc which may have
24     FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25     declared with attribute warn_unused_result" were given. Just casting the
26     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 516
29     7. Minor change to pcretest.c to avoid a compiler warning.
30 ph10 512
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    
35     9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36     use Unicode properties. (*UCP) at the start of a pattern can be used to set
37     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 519
40     10. Added --line-buffered to pcregrep.
41 ph10 513
42 ph10 520 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     127 whose first byte was different to the first byte of the other case of
45     the letter, the other case of this starting letter was not recognized.
46 ph10 521
47     12. pcreposix.c included pcre.h before including pcre_internal.h. This caused a
48     conflict in the definition of PCRE_EXP_DECL. I have removed the include of
49     pcre.h as pcre_internal.h includes pcre.h itself. (This may be a bit of
50     historical tidying that never got done.)
51 ph10 523
52     13. If a pattern that was studied started with a repeated Unicode property
53     test, for example, \p{Nd}+, there was the theoretical possibility of
54     setting up an incorrect bitmap of starting bytes, but fortunately it could
55     not have actually happened in practice until change 8 above was made (it
56     added property types that matched character-matching opcodes).
57 ph10 524
58     14. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
59     possible starting bytes for non-anchored patterns.
60 ph10 528
61     15. The "auto-possessify" feature of pcre_compile() now recognizes \R.
62 ph10 529
63     16. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
64     input, it could crash or give wrong results if characters with values
65     greater than 0xc0 were present in the subject string. (Detail: it assumed
66     UTF-8 input when processing these items.)
67 ph10 521
68 ph10 517
69 ph10 520
70 ph10 508 Version 8.02 19-Mar-2010
71 ph10 491 ------------------------
72    
73     1. The Unicode data tables have been updated to Unicode 5.2.0.
74    
75 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
76     configured.
77 ph10 507
78 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
79 ph10 507 original author of that file, following a query about its status.
80    
81     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
82 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
83 ph10 507
84 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
85     quantifier applied to a forward-referencing subroutine call, could compile
86     incorrect code or give the error "internal error: previously-checked
87     referenced subpattern not found".
88 ph10 507
89     6. Both MS Visual Studio and Symbian OS have problems with initializing
90 ph10 497 variables to point to external functions. For these systems, therefore,
91     pcre_malloc etc. are now initialized to local functions that call the
92     relevant global functions.
93 ph10 507
94 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
95     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
96 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
97     the lengths are correct (equal to the number of opcodes).
98    
99     8. Following on from 7, I added a similar kludge to check the length of the
100     eint vector in pcreposix.c.
101    
102     9. Error texts for pcre_compile() are held as one long string to avoid too
103     much relocation at load time. To find a text, the string is searched,
104 ph10 499 counting zeros. There was no check for running off the end of the string,
105     which could happen if a new error number was added without updating the
106 ph10 507 string.
107    
108     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
109    
110 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
111 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
112     \K is "not well defined" if used in an assertion. PCRE now accepts it if
113     the assertion is positive, but not if it is negative.
114    
115 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
116 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
117     implementation of support for (*MARK) will need an extra pointer on the
118 ph10 501 stack; I have reserved it now, so that the stack frame size does not
119     decrease.
120 ph10 507
121     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
122     item in branch that calls a recursion is a subroutine call - as in the
123 ph10 503 second branch in the above example - was incorrectly given the compile-
124     time error "recursive call could loop indefinitely" because pcre_compile()
125 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
126    
127 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
128 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
129 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
130 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
131 ph10 491
132 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
133 ph10 492
134 ph10 507
135 ph10 489 Version 8.01 19-Jan-2010
136     ------------------------
137 ph10 471
138     1. If a pattern contained a conditional subpattern with only one branch (in
139 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
140 ph10 473 computed the wrong minimum data length (which is of course zero for such
141 ph10 489 subpatterns). This could cause incorrect "no match" results.
142 ph10 473
143     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
144 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
145     "internal error: code overflow at offset...". This happened only when
146 ph10 473 the reset was to the original external option setting. (An optimization
147     abstracts leading options settings into an external setting, which was the
148 ph10 472 cause of this.)
149 ph10 471
150 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
151     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
152     assertion pattern did not match (meaning that the assertion was true), it
153     was incorrectly treated as false if the SKIP had been reached during the
154     matching. This also applied to assertions used as conditions.
155 ph10 471
156 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
157     assertion subpattern, including such a pattern used as a condition,
158     unpredictable results occurred, instead of the error return
159     PCRE_ERROR_DFA_UITEM.
160 ph10 478
161 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
162     situation when an empty string is matched. It now does the fancy magic
163 ph10 478 stuff that is necessary.
164    
165     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
166 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
167 ph10 478
168 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
169     as part of something else:
170 ph10 478
171     (a) Change DEBUG to PCRE_DEBUG.
172    
173     (b) In pcre_compile(), rename the member of the "branch_chain" structure
174     called "current" as "current_branch", to prevent a collision with the
175 ph10 475 Linux macro when compiled as a kernel module.
176 ph10 478
177     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
178     prevent a collision with the Linux macro when compiled as a kernel
179 ph10 475 module.
180 ph10 478
181 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
182     cast potentially large values to (double). This has been changed to that
183 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
184     instead, thus avoiding the use of floating point arithmetic. (There is no
185     other use of FP in PCRE.) If int64_t is not found, the fallback is to
186     double.
187    
188     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
189 ph10 476 2005 (difference between two addresses compared to an unsigned value).
190 ph10 473
191 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
192     custom one, because of the following reported problem in Windows:
193 ph10 473
194 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
195 ph10 489 under Win32.
196 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
197 ph10 489 therefore missing the function definition.
198 ph10 478 - The compiler thus generates a "C" signature for the test function.
199     - The linker fails to find the "C" function.
200     - PCRE fails to configure if asked to do so against libbz2.
201 ph10 486
202 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
203     messages were output:
204 ph10 478
205 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
206     rerunning libtoolize, to keep the correct libtool macros in-tree.
207     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
208 ph10 486
209 ph10 479 I have done both of these things.
210 ph10 486
211 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
212 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
213     runaway infinite recursion. I updated the discussion in the pcrestack man
214     page.
215    
216     13. Now that we have gone to the x.xx style of version numbers, the minor
217     version may start with zero. Using 08 or 09 is a bad idea because users
218     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
219     interpreted as invalid octal numbers. I've updated the previous comment in
220     configure.ac, and also added a check that gives an error if 08 or 09 are
221 ph10 481 used.
222 ph10 486
223 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
224 ph10 483 causing partial matching to fail when the end of the subject matched \W
225     in a UTF-8 pattern where \W was quantified with a minimum of 3.
226 ph10 486
227 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
228 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
229 ph10 483 their definitions. The declarations used "const uschar *" and the
230     definitions used USPTR. Even though USPTR is normally defined as "const
231     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
232     reported that: "This difference in casting confuses some C++ compilers, for
233     example, SunCC recognizes above declarations as different functions and
234 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
235 ph10 483 USPTR.
236 ph10 486
237     16. GNU libtool is named differently on some systems. The autogen.sh script now
238 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
239     (FreeBSD).
240 ph10 478
241 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
242     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
243     comment: "Figure out how to create a longlong from a string: strtoll and
244     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
245     instance, but it only takes 2 args instead of 3!"
246 ph10 479
247 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
248     specification, with a corresponding code fix. A pattern such as
249     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
250     refers, was giving matches when it shouldn't. For example, xa=xaaa would
251     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
252     same bug. Such groups have to be quantified to be useful, or contained
253     inside another quantified group. (If there's no repetition, the reference
254     can never match.) The problem arises because, having left the group and
255     moved on to the rest of the pattern, a later failure that backtracks into
256     the group uses the captured value from the final iteration of the group
257     rather than the correct earlier one. I have fixed this in PCRE by forcing
258     any group that contains a reference to itself to be an atomic group; that
259     is, there cannot be any backtracking into it once it has completed. This is
260     similar to recursive and subroutine calls.
261 ph10 486
262 ph10 488
263 ph10 469 Version 8.00 19-Oct-09
264 ph10 418 ----------------------
265    
266     1. The table for translating pcre_compile() error codes into POSIX error codes
267 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
268     being within the table. This could lead to an OK return being given in
269 ph10 418 error.
270 ph10 461
271     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
272     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
273     in a Windows environment.
274    
275 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
276     zero, as does GNU grep. However, pcregrep was also printing all files when
277     --files-with-matches was added. Now, when both options are given, it prints
278     counts only for those files that have at least one match. (GNU grep just
279 ph10 461 prints the file name in this circumstance, but including the count seems
280     more useful - otherwise, why use --count?) Also ensured that the
281 ph10 420 combination -clh just lists non-zero counts, with no names.
282 ph10 461
283     4. The long form of the pcregrep -F option was incorrectly implemented as
284     --fixed_strings instead of --fixed-strings. This is an incompatible change,
285     but it seems right to fix it, and I didn't think it was worth preserving
286     the old behaviour.
287    
288     5. The command line items --regex=pattern and --regexp=pattern were not
289 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
290 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
291 ph10 422 which are compatible with GNU grep; these now work.
292 ph10 461
293     6. No libpcreposix.pc file was created for pkg-config; there was just
294 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
295 ph10 461
296 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
297 ph10 461 when UCP support is not needed, by modifying the Python script that
298 ph10 425 generates it from Unicode data files. This should not matter if the module
299     is correctly used as a library, but I received one complaint about 50K of
300     unwanted data. My guess is that the person linked everything into his
301     program rather than using a library. Anyway, it does no harm.
302 ph10 461
303 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
304 ph10 461 was a minimum greater than 1 for a wide character in a possessive
305 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
306     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
307     character. Chaos in the form of incorrect output or a compiling loop could
308     result.
309 ph10 461
310 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
311 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
312 ph10 426 partially matched by this function. In addition, if there are at least two
313 ph10 435 slots in the offset vector, the offset of the earliest inspected character
314     for the match and the offset of the end of the subject are set in them when
315 ph10 461 PCRE_ERROR_PARTIAL is returned.
316    
317 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
318     synonymous with PCRE_PARTIAL, for backwards compatibility, and
319     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
320 ph10 462 and may be more useful for multi-segment matching.
321 ph10 461
322     11. Partial matching with pcre_exec() is now more intuitive. A partial match
323     used to be given if ever the end of the subject was reached; now it is
324     given only if matching could not proceed because another character was
325     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
326     string "Z", which now yields "no match" instead of "partial match". In the
327     case of pcre_dfa_exec(), "no match" is given if every matching path for the
328     final character ended with (*FAIL).
329    
330 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
331 ph10 461 if the pattern had a "must contain" character that was already found in the
332 ph10 428 earlier partial match, unless partial matching was again requested. For
333     example, with the pattern /dog.(body)?/, the "must contain" character is
334     "g". If the first part-match was for the string "dog", restarting with
335 ph10 435 "sbody" failed. This bug has been fixed.
336 ph10 461
337     13. The string returned by pcre_dfa_exec() after a partial match has been
338     changed so that it starts at the first inspected character rather than the
339     first character of the match. This makes a difference only if the pattern
340     starts with a lookbehind assertion or \b or \B (\K is not supported by
341     pcre_dfa_exec()). It's an incompatible change, but it makes the two
342 ph10 435 matching functions compatible, and I think it's the right thing to do.
343 ph10 461
344 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
345 ph10 461 so that the demonstration program is easily available in environments where
346     PCRE has not been installed from source.
347    
348 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
349 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
350     library.
351 ph10 461
352 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
353 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
354 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
355 ph10 433 these options useful.
356 ph10 461
357     17. If a caller to the POSIX matching function regexec() passes a non-zero
358 ph10 438 value for nmatch with a NULL value for pmatch, the value of
359 ph10 461 nmatch is forced to zero.
360    
361 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
362 ph10 461 the diff command, as RunTest does. It now checks in the same way as
363 ph10 437 RunTest, and also checks for the -b option.
364 ph10 461
365 ph10 438 19. If an odd number of negated classes containing just a single character
366     interposed, within parentheses, between a forward reference to a named
367 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
368     an internal error, complaining that it could not find the referenced
369 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
370 ph10 461 [The bug was that it was starting one character too far in when skipping
371     over the character class, thus treating the ] as data rather than
372     terminating the class. This meant it could skip too much.]
373    
374 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
375 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
376 ph10 442 to have an empty string match not at the start, even when the pattern is
377 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
378    
379 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
380 ph10 461 than the maximum at the outer level, the higher number was returned, but
381     with unset values at the outer level. The correct (outer level) value is
382 ph10 446 now given.
383 ph10 461
384 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
385     PCRE did not set those parentheses (unlike Perl). I have now found a way to
386     make it do so. The string so far is captured, making this feature
387     compatible with Perl.
388 ph10 461
389     23. The tests have been re-organized, adding tests 11 and 12, to make it
390 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
391 ph10 461
392 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
393 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
394     does. Neither allows recursion.
395    
396     25. I finally figured out how to implement a request to provide the minimum
397     length of subject string that was needed in order to match a given pattern.
398     (It was back references and recursion that I had previously got hung up
399     on.) This code has now been added to pcre_study(); it finds a lower bound
400 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
401     bound, but using it to avoid searching strings that are too short does give
402     some useful speed-ups. The value is available to calling programs via
403     pcre_fullinfo().
404 ph10 461
405 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
406     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
407     study optimizations had never been tested with that matching function.
408     Oops. What is worse, even when it was passed study data, there was a bug in
409     pcre_dfa_exec() that meant it never actually used it. Double oops. There
410     were also very few tests of studied patterns with pcre_dfa_exec().
411 ph10 461
412 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
413     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
414     on the other side of the coin, they are no longer allowed to have different
415     names, because these cannot be distinguished in PCRE, and this has caused
416     confusion. (This is a difference from Perl.)
417 ph10 461
418     28. When duplicate subpattern names are present (necessarily with different
419     numbers, as required by 27 above), and a test is made by name in a
420     conditional pattern, either for a subpattern having been matched, or for
421     recursion in such a pattern, all the associated numbered subpatterns are
422 ph10 459 tested, and the overall condition is true if the condition is true for any
423     one of them. This is the way Perl works, and is also more like the way
424     testing by number works.
425 ph10 418
426 ph10 461
427 ph10 412 Version 7.9 11-Apr-09
428 ph10 376 ---------------------
429    
430 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
431 ph10 376 (pcretest), all targets were linked against these libraries. This included
432     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
433     libraries. This caused unwanted dependencies to be created. This problem
434 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
435 ph10 376 pcretest is linked with readline.
436 ph10 392
437 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
438     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
439     moved outside it again, because FALSE and TRUE are already defined in AIX,
440     but BOOL is not.
441 ph10 392
442     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
443 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
444 ph10 392
445 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
446     hyphens) following file names and line numbers when outputting matching
447 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
448 ph10 376 wording for the --colour (or --color) option.
449 ph10 392
450 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
451     was not coloured; this is different to GNU grep, so I have changed it to be
452     the same.
453 ph10 392
454 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
455 ph10 392 each matching line was coloured. Now it goes on to look for further matches
456     of any of the test patterns, which is the same behaviour as GNU grep.
457    
458     7. A pattern that could match an empty string could cause pcregrep to loop; it
459     doesn't make sense to accept an empty string match in pcregrep, so I have
460 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
461     seems to be how GNU grep behaves.
462 ph10 392
463 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
464 ph10 392 start or after a newline", because the conditional assertion was not being
465     correctly handled. The rule now is that both the assertion and what follows
466     in the first alternative must satisfy the test.
467    
468 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
469 ph10 399 condition was an assertion, PCRE could crash during matching, both with
470     pcre_exec() and pcre_dfa_exec().
471 ph10 392
472     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
473     used for matching.
474    
475     11. Unicode property support in character classes was not working for
476 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
477 ph10 388
478 ph10 392 12. Added the -M command line option to pcretest.
479    
480 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
481 ph10 389
482     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
483 ph10 390
484 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
485 ph10 390 wrapper.
486 ph10 392
487 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
488 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
489 ph10 391 string constants.
490 ph10 405
491 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
492     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
493 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
494     these, but not everybody uses configure.
495    
496     19. A conditional group that had only one branch was not being correctly
497     recognized as an item that could match an empty string. This meant that an
498     enclosing group might also not be so recognized, causing infinite looping
499     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
500     with the subject "ab", where knowledge that the repeated group can match
501 ph10 396 nothing is needed in order to break the loop.
502 ph10 405
503 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
504 ph10 405 exec(), but without supplying a callout function, matching went wrong.
505    
506     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
507     leak if the size of the offset vector was greater than 30. When the vector
508     is smaller, the saved offsets during recursion go onto a local stack
509     vector, but for larger vectors malloc() is used. It was failing to free
510     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
511 ph10 400 error, in fact).
512 ph10 405
513 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
514 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
515     problem, but was untidy.
516 ph10 376
517 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
518     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
519     included within another project.
520 ph10 411
521 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
522     slightly modified by me:
523 ph10 411
524     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
525     not building pcregrep.
526    
527 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
528 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
529    
530 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
531     duplicate group numbers, could behave incorrectly or give incorrect errors,
532     because when scanning forward to find the reference group, PCRE was not
533     taking into account the duplicate group numbers. A pattern such as
534     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
535 ph10 411
536     26. Changed a few more instances of "const unsigned char *" to USPTR, making
537     the feature of a custom pointer more persuasive (as requested by a user).
538 ph10 416
539 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
540 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
541     pre-defined.
542 ph10 392
543 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
544    
545 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
546     in the configuration summary.
547 ph10 405
548 ph10 411
549 ph10 374 Version 7.8 05-Sep-08
550 ph10 349 ---------------------
551    
552     1. Replaced UCP searching code with optimized version as implemented for Ad
553     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
554 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
555     to 5 times on some simple patterns that I tested. Permission was given to
556     distribute the MultiStage2.py script that generates the tables (it's not in
557     the tarball, but is in the Subversion repository).
558 ph10 349
559 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
560     scripts.
561 ph10 358
562 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
563     a group with a zero qualifier. The result of the study could be incorrect,
564 ph10 358 or the function might crash, depending on the pattern.
565    
566     4. Caseless matching was not working for non-ASCII characters in back
567 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
568 ph10 358 It now works when Unicode Property Support is available.
569    
570 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
571     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
572     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
573 ph10 358 truncation.
574 ph10 349
575 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
576    
577 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
578     pointers, in case they are 64-bit values.
579 ph10 371
580     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
581     test 2 if it fails.
582    
583 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
584 ph10 371 and a #define of that name to empty if it is not externally set. This is to
585     allow users of MSVC to set it if necessary.
586    
587     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
588 ph10 359 the convenience functions in the pcre_get.c source file.
589 ph10 371
590 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
591     could cause overwriting and/or a crash. This command provoked a crash in
592 ph10 371 some environments:
593    
594     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
595    
596 ph10 360 This potential security problem was recorded as CVE-2008-2371.
597 ph10 371
598 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
599     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
600 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
601 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
602     pcretest so that it places the subject at the end of its malloc-ed buffer.
603 ph10 371
604 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
605 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
606    
607 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
608 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
609     first line. This applied both to normal and DFA matching.
610    
611 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
612 ph10 371 /^[^d]*?$/8 failed to match "abc".
613 ph10 351
614 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
615    
616     17. Make it more clear in the documentation that values returned from
617 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
618 ph10 357
619 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
620 ph10 368
621 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
622     supplied by Stefan Weber. I made a further small update for 7.8 because
623 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
624     replaced by pcre_ucd.c.
625 ph10 371
626 ph10 373
627 ph10 347 Version 7.7 07-May-08
628 ph10 321 ---------------------
629    
630     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
631 ph10 345 a string to a long long, pretend we don't even have a long long." This is
632 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
633 ph10 345
634 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
635     pre-7.6 versions, which defined a global no_arg variable instead of putting
636 ph10 332 it in the RE class. (See also #8 below.)
637 ph10 345
638     3. Remove a line of dead code, identified by coverity and reported by Nuno
639     Lopes.
640    
641 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
642 ph10 321
643 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
644 ph10 345 of files, instead of just to the final components.
645    
646 ph10 324 (2) If there was more than one level of directory, the subdirectories were
647     skipped unless they satisfied the include/exclude conditions. This is
648     inconsistent with GNU grep (and could even be seen as contrary to the
649     pcregrep specification - which I improved to make it absolutely clear).
650     The action now is always to scan all levels of directory, and just
651     apply the include/exclude patterns to regular files.
652 ph10 345
653 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
654 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
655    
656 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
657 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
658 ph10 326 doesn't support NULs in patterns.
659 ph10 345
660     7. Added some missing "const"s to declarations of static tables in
661     pcre_compile.c and pcre_dfa_exec.c.
662    
663 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
664 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
665 ph10 345 first patch. And a third patch - this was a messy problem.)
666 ph10 321
667 ph10 345 9. Applied Craig's patch to remove the use of push_back().
668    
669 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
670     matching function regexec().
671 ph10 345
672     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
673     which, however, unlike Perl's \g{...}, are subroutine calls, not back
674 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
675     Oniguruma does).
676 ph10 345
677     12. Previously, a group with a zero repeat such as (...){0} was completely
678 ph10 335 omitted from the compiled regex. However, this means that if the group
679     was called as a subroutine from elsewhere in the pattern, things went wrong
680 ph10 345 (an internal error was given). Such groups are now left in the compiled
681     pattern, with a new opcode that causes them to be skipped at execution
682 ph10 335 time.
683 ph10 345
684 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
685     to the way PCRE behaves:
686 ph10 345
687 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
688 ph10 345
689     (b) A back reference to an unmatched subpattern matches an empty string
690 ph10 336 (Perl fails the current match path).
691 ph10 345
692 ph10 341 (c) A data ] in a character class must be notated as \] because if the
693 ph10 345 first data character in a class is ], it defines an empty class. (In
694 ph10 341 Perl it is not possible to have an empty class.) The empty class []
695     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
696     The negative empty class [^] matches any one character, independently
697     of the DOTALL setting.
698 ph10 345
699     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
700 ph10 340 non-existent subpattern following a character class starting with ']' and
701     containing () gave an internal compiling error instead of "reference to
702     non-existent subpattern". Fortunately, when the pattern did exist, the
703 ph10 345 compiled code was correct. (When scanning forwards to check for the
704 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
705 ph10 345 the class, so got the count wrong. When actually compiling, the reference
706 ph10 340 was subsequently set up correctly.)
707 ph10 345
708 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
709 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
710     other assertions are supported. I have made pcre_dfa_exec() support
711     (*FAIL).
712    
713 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
714 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
715     cannot be changed at match time, I realized I could make a small
716     improvement to matching performance by compiling OP_ALLANY instead of
717     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
718     on the OP_ANY path.
719    
720     17. Compiling pcretest on Windows with readline support failed without the
721 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
722 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
723    
724 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
725 ph10 345 ncurses library to be included for pcretest when ReadLine support is
726     requested, but also to allow for it to be overridden. This patch came from
727     Daniel Bergström.
728 ph10 347
729 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
730 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
731     any errors with the current Unicode tables. Thanks to Peter Kankowski for
732     spotting this.
733 ph10 324
734 ph10 332
735 ph10 319 Version 7.6 28-Jan-08
736 ph10 300 ---------------------
737    
738 ph10 302 1. A character class containing a very large number of characters with
739     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
740     overflow.
741 ph10 309
742     2. Patch to cut out the "long long" test in pcrecpp_unittest when
743     HAVE_LONG_LONG is not defined.
744    
745 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
746 ph10 304 bring them up to date and include new features. This patch includes:
747 ph10 309
748 ph10 304 - Fixed PH's badly added libz and libbz2 support.
749     - Fixed a problem with static linking.
750 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
751 ph10 304 - Fixed dftables problem and added an option.
752     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
753     HAVE_LONG_LONG.
754     - Added readline support for pcretest.
755 ph10 309 - Added an listing of the option settings after cmake has run.
756    
757 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
758     "pcre.dll" under mingw when using Configure/Make. I added stuff to
759     Makefile.am that cause it to include this special target, without
760     affecting anything else. Note that the same mingw target plus all
761     the other distribution libraries and programs are now supported
762     when configuring with CMake (see 6 below) instead of with
763     Configure/Make.
764 ph10 309
765 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
766     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
767 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
768     solves the problem, but it does no harm.
769 ph10 313
770 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
771 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
772 ph10 314 with CMake, and also correct the comment about stack recursion.
773 ph10 313
774 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
775 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
776     of a program that users should build themselves after PCRE is installed, so
777     building it automatically is not really right. What is more, it gave
778 ph10 312 trouble in some build environments.
779 ph10 300
780 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
781 ph10 308
782 ph10 319
783 ph10 298 Version 7.5 10-Jan-08
784 ph10 263 ---------------------
785    
786     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
787     values in parens when parsing an RE using the C++ wrapper."
788 ph10 286
789 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
790     Characters greater than 255 were excluded from the class instead of being
791     included.
792 ph10 286
793     3. The same bug as (2) above applied to negated POSIX classes such as
794 ph10 265 [:^space:].
795 ph10 286
796 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
797     defined or documented. It seems to have been a typo for PCRE_STATIC, so
798 ph10 286 I have changed it.
799    
800 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
801 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
802     first named subpattern whose name started with "a" (in other words, the
803 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
804     expected" is now given for (?&) (a zero-length name), and this patch also
805     makes it give the same error for \k'' (previously it complained that that
806     was a reference to a non-existent subpattern).
807 ph10 286
808 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
809 ph10 286 this is right because (?- can be followed by option settings as well as by
810 ph10 269 digits. I have, however, made the messages clearer.
811 ph10 286
812 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
813     than the number used in the conditional) now cause a compile-time error.
814     This is actually not compatible with Perl, which accepts such patterns, but
815     treats the conditional as always being FALSE (as PCRE used to), but it
816     seems to me that giving a diagnostic is better.
817 ph10 286
818 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
819 ph10 275 and messages.
820 ph10 286
821     9. Fix two occurrences of "backslash" in comments that should have been
822     "backspace".
823    
824     10. Remove two redundant lines of code that can never be obeyed (their function
825     was moved elsewhere).
826    
827     11. The program that makes PCRE's Unicode character property table had a bug
828     which caused it to generate incorrect table entries for sequences of
829 ph10 277 characters that have the same character type, but are in different scripts.
830 ph10 286 It amalgamated them into a single range, with the script of the first of
831 ph10 277 them. In other words, some characters were in the wrong script. There were
832     thirteen such cases, affecting characters in the following ranges:
833 ph10 286
834 ph10 277 U+002b0 - U+002c1
835     U+0060c - U+0060d
836 ph10 286 U+0061e - U+00612
837 ph10 277 U+0064b - U+0065e
838     U+0074d - U+0076d
839     U+01800 - U+01805
840     U+01d00 - U+01d77
841     U+01d9b - U+01dbf
842     U+0200b - U+0200f
843     U+030fc - U+030fe
844     U+03260 - U+0327f
845     U+0fb46 - U+0fbb1
846     U+10450 - U+1049d
847 ph10 286
848 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
849     compatible with GNU grep in that, if there was more than one match in a
850     line, it showed only the first of them. It now behaves in the same way as
851     GNU grep.
852 ph10 286
853     13. If the -o and -v options were combined for pcregrep, it printed a blank
854     line for every non-matching line. GNU grep prints nothing, and pcregrep now
855     does the same. The return code can be used to tell if there were any
856     non-matching lines.
857    
858 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
859    
860     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
861 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
862 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
863     and both kinds of lookbehind were skipped).
864    
865 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
866 ph10 284 inclusion of <windows.h> to before rather than after the definition of
867     INVALID_FILE_ATTRIBUTES (patch from David Byron).
868 ph10 263
869 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
870 ph10 286 character property caused pcre_compile() to compile bad code, which led at
871     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
872     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
873     caused the error; without that there was no problem.
874 ph10 263
875 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
876 ph10 286
877 ph10 289 19. Added --enable-pcretest-libreadline.
878 ph10 286
879 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
880 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
881 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
882     later patch that removed the other one (the right fix) and added unit tests
883     that check the return values (which was not done before).
884 ph10 292
885 ph10 291 21. Several CMake things:
886 ph10 287
887 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
888 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
889 ph10 288
890 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
891     linked with the newly-built libraries, not previously installed ones.
892 ph10 291
893 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
894 ph10 298
895     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
896     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
897     UTF-8 newline character). The key issue is that the pattern starts .*;
898     this means that the match must be either at the beginning, or after a
899     newline. The bug was in the code for advancing after a failed match and
900     checking that the new position followed a newline. It was not taking
901 ph10 294 account of UTF-8 characters correctly.
902 ph10 298
903     23. PCRE was behaving differently from Perl in the way it recognized POSIX
904     character classes. PCRE was not treating the sequence [:...:] as a
905     character class unless the ... were all letters. Perl, however, seems to
906     allow any characters between [: and :], though of course it rejects as
907     unknown any "names" that contain non-letters, because all the known class
908     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
909     for example, whereas PCRE did not - it did not recognize a POSIX character
910     class. This seemed a bit dangerous, so the code has been changed to be
911     closer to Perl. The behaviour is not identical to Perl, because PCRE will
912     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
913     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
914     Perl does, and where it didn't before.
915    
916 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
917     Windows environments %n is disabled by default.
918 ph10 292
919    
920 ph10 260 Version 7.4 21-Sep-07
921 ph10 230 ---------------------
922    
923     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
924 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
925     LF". That isn't really right - the whole point of the change was to try to
926     help when there was an actual mention of one of the two characters. So now
927     the change happens only if \r or \n (or a literal CR or LF) character is
928 ph10 230 encountered.
929 ph10 231
930     2. The 32-bit options word was also used for 6 internal flags, but the numbers
931     of both had grown to the point where there were only 3 bits left.
932     Fortunately, there was spare space in the data structure, and so I have
933     moved the internal flags into a new 16-bit field to free up more option
934 ph10 230 bits.
935 ph10 231
936     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
937     but did not set the internal JCHANGED flag - either of these is enough to
938     control the way the "get" function works - but the PCRE_INFO_JCHANGED
939     facility is supposed to tell if (?J) was ever used, so now (?J) at the
940 ph10 230 start sets both bits.
941    
942 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
943     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
944 ph10 230
945 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
946    
947     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
948 ph10 233 compatibility, even though it is no longer used.
949 ph10 243
950     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
951 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
952 ph10 259 windows.h file is present (where different names are used). [This was
953 ph10 257 reversed later after testing - see 16 below.]
954 ph10 243
955     8. Changed all #include <config.h> to #include "config.h". There were also
956 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
957 ph10 243
958 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
959 ph10 243 sequence off the lines that it output.
960    
961     10. It was pointed out to me that arrays of string pointers cause lots of
962     relocations when a shared library is dynamically loaded. A technique of
963     using a single long string with a table of offsets can drastically reduce
964     these. I have refactored PCRE in four places to do this. The result is
965 ph10 240 dramatic:
966 ph10 243
967 ph10 240 Originally: 290
968     After changing UCP table: 187
969 ph10 243 After changing error message table: 43
970 ph10 240 After changing table of "verbs" 36
971     After changing table of Posix names 22
972 ph10 243
973 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
974 ph10 247
975 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
976 ph10 247 unicode-properties was also set.
977    
978 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
979 ph10 231
980 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
981     checked only for CRLF.
982 ph10 233
983 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
984    
985 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
986 ph10 253
987 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
988 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
989     entirely. This removes changes made in 7 above.
990 ph10 256
991 ph10 261 17. The CMake files have been updated, and there is now more information about
992     building with CMake in the NON-UNIX-USE document.
993 ph10 257
994 ph10 261
995 ph10 228 Version 7.3 28-Aug-07
996 ph10 157 ---------------------
997    
998 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
999     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1000     brackets there is not right, since it causes compilers to look for an
1001     installed pcre.h, not the version that is in the source that is being
1002     compiled (which of course may be different). I have changed it back to:
1003 ph10 197
1004 ph10 189 #include "pcre.h"
1005 ph10 197
1006     I have a vague recollection that the change was concerned with compiling in
1007     different directories, but in the new build system, that is taken care of
1008     by the VPATH setting the Makefile.
1009    
1010 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1011     when the subject happened to end in the byte 0x85 (e.g. if the last
1012     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1013     characters but of course it shouldn't be taken as a newline when it is part
1014     of another character. The bug was that, for an unlimited repeat of . in
1015     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1016     characters when looking for a newline.
1017 ph10 197
1018     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1019    
1020     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1021     in debug output.
1022    
1023 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1024     long printing in the pcrecpp unittest when running under MinGW.
1025 ph10 189
1026 ph10 197 6. ESC_K was left out of the EBCDIC table.
1027 ph10 189
1028 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1029     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1030     limit also applies to "virtual nesting" when a pattern is recursive, and in
1031     this case 1000 isn't so big. I have been able to remove this limit at the
1032     expense of backing off one optimization in certain circumstances. Normally,
1033     when pcre_exec() would call its internal match() function recursively and
1034     immediately return the result unconditionally, it uses a "tail recursion"
1035     feature to save stack. However, when a subpattern that can match an empty
1036     string has an unlimited repetition quantifier, it no longer makes this
1037     optimization. That gives it a stack frame in which to save the data for
1038     checking that an empty string has been matched. Previously this was taken
1039     from the 1000-entry workspace that had been reserved. So now there is no
1040     explicit limit, but more stack is used.
1041 ph10 189
1042 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1043     syntax that is required for Windows, and which was going wrong for the
1044     pcreposix and pcrecpp parts of the library. These were overlooked when this
1045     problem was solved for the main library.
1046 ph10 197
1047 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1048     the size of patterns that contain repeated groups with explicit upper
1049     limits. As the maximum quantifier is 65535, the maximum group length was
1050     set at 30,000 so that the product of these two numbers did not overflow a
1051     32-bit integer. However, it turns out that people want to use groups that
1052     are longer than 30,000 bytes (though not repeat them that many times).
1053     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1054     made it possible to implement the integer overflow checks in a much more
1055     dynamic way, which I have now done. The artificial limitation on group
1056     length has been removed - we now have only the limit on the total length of
1057     the compiled pattern, which depends on the LINK_SIZE setting.
1058 ph10 208
1059     10. Fixed a bug in the documentation for get/copy named substring when
1060     duplicate names are permitted. If none of the named substrings are set, the
1061     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1062     empty string.
1063    
1064     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1065     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1066     because the ] is interpreted as the first data character and the
1067     terminating ] is not found. PCRE has been made compatible with Perl in this
1068     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1069     cause memory overwriting.
1070    
1071 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1072     string has been matched (to stop an infinite loop). It was not recognizing
1073 ph10 208 a conditional subpattern that could match an empty string if that
1074 ph10 206 subpattern was within another subpattern. For example, it looped when
1075 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1076 ph10 206 condition was not nested. This bug has been fixed.
1077 ph10 208
1078 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1079     past the start of the subject in the presence of bytes with the top bit
1080     set, for example "\x8aBCD".
1081 ph10 211
1082 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1083     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1084 ph10 200
1085 ph10 211 14. Optimized (?!) to (*FAIL).
1086 ph10 202
1087 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1088     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1089     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1090     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1091     does: it's just the validity check that is more restrictive.
1092 ph10 220
1093     16. Inserted checks for integer overflows during escape sequence (backslash)
1094     processing, and also fixed erroneous offset values for syntax errors during
1095     backslash processing.
1096    
1097 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1098 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1099    
1100 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1101     caused an overrun.
1102 ph10 220
1103     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1104     something other than just ASCII characters) inside a group that had an
1105     unlimited repeat caused a loop at compile time (while checking to see
1106     whether the group could match an empty string).
1107    
1108 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1109     [\P{Any}] did so. (Error in the code for printing property names.)
1110 ph10 210
1111 ph10 220 21. An orphan \E inside a character class could cause a crash.
1112    
1113     22. A repeated capturing bracket such as (A)? could cause a wild memory
1114 ph10 218 reference during compilation.
1115 ph10 220
1116     23. There are several functions in pcre_compile() that scan along a compiled
1117     expression for various reasons (e.g. to see if it's fixed length for look
1118 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1119 ph10 220 present in the pattern. These operators have additional parameters compared
1120     with \d, etc, and these were not being taken into account when moving along
1121 ph10 218 the compiled data. Specifically:
1122 ph10 220
1123     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1124     length.
1125    
1126     (b) An item such as \pL+ within a repeated group could cause crashes or
1127 ph10 218 loops.
1128 ph10 220
1129 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1130 ph10 220 "reference to non-existent subpattern" error.
1131    
1132 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1133    
1134 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1135 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1136 ph10 211
1137 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1138 ph10 218
1139 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1140 ph10 223 character were causing crashes (broken optimization).
1141 ph10 227
1142 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1143 ph10 227 \p or \P) caused a compile-time loop.
1144    
1145 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1146     break. For example, the unstudied pattern [\r\n]A does not match the string
1147     "\r\nA" because change 7.0/46 below moves the current point on by two
1148     characters after failing to match at the start. However, the pattern \nA
1149 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1150     the same is true. There doesn't seem any very clean way out of this, but
1151     what I have chosen to do makes the common cases work: PCRE now takes note
1152     of whether there can be an explicit match for \r or \n anywhere in the
1153     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1154     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1155     pattern has explicit CR or LF references.
1156 ph10 222
1157 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1158 ph10 223
1159 ph10 227
1160 ph10 189 Version 7.2 19-Jun-07
1161     ---------------------
1162    
1163 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1164     which is apparently normally available under Windows.
1165 ph10 159
1166     2. Re-jig the pcregrep tests with different newline settings in an attempt
1167     to make them independent of the local environment's newline setting.
1168 ph10 157
1169 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1170 ph10 165
1171 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1172     was not 2, because the output contained actual offsets. The recent new
1173 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1174     usable with all link sizes.
1175    
1176 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1177     stack recursion. This gives a massive performance boost under BSD, but just
1178 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1179 ph10 164 in all cases.
1180 ph10 172
1181 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1182 ph10 172
1183 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1184     recursion call. It refers to the nth most recently opened parentheses.
1185 ph10 172
1186 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1187 ph10 172 to be opened parentheses.
1188    
1189     (c) Conditions that refer to capturing parentheses can be specified
1190 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1191 ph10 172
1192 ph10 168 (d) \K resets the start of the current match so that everything before
1193 ph10 172 is not part of it.
1194    
1195 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1196 ph10 172
1197 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1198 ph10 172 reference syntax.
1199 ph10 182
1200 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1201 ph10 182 alternative starts with the same number.
1202 ph10 172
1203 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1204    
1205 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1206     PCRE_INFO_JCHANGED.
1207    
1208     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1209     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1210 ph10 170 for detecting groups that can match an empty string.
1211 ph10 159
1212 ph10 172 9. A pattern with a very large number of alternatives (more than several
1213     hundred) was running out of internal workspace during the pre-compile
1214     phase, where pcre_compile() figures out how much memory will be needed. A
1215     bit of new cunning has reduced the workspace needed for groups with
1216     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1217     workspace instead of running out of the 4096 that are available.
1218 ph10 182
1219 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1220 ph10 172
1221 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1222     The report of the bug said:
1223 ph10 182
1224 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1225     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1226 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1227 ph10 185
1228 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1229 ph10 185 it matched the wrong number of bytes.
1230 ph10 172
1231 ph10 179
1232 ph10 155 Version 7.1 24-Apr-07
1233 ph10 98 ---------------------
1234    
1235 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1236 ph10 122 that is more "standard", making use of automake and other Autotools. There
1237 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1238     on this.
1239 ph10 111
1240     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1241     for recursive directory scanning broke on some systems because the files
1242     are not scanned in any specific order and on different systems the order
1243     was different. A call to "sort" has been inserted into RunGrepTest for the
1244     approprate test as a short-term fix. In the longer term there may be an
1245 ph10 100 alternative.
1246 ph10 111
1247 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1248 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1249     people do their own conversions for various reasons). The problems
1250     concerned the use of low-level troff macros .br and .in. I have therefore
1251     removed all such uses from the man pages (some were redundant, some could
1252 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1253     HTML has been updated to handle .nf/.fi and to complain if it encounters
1254     .br or .in.
1255 ph10 111
1256 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1257 ph10 123 arranged for config.h to be included in the distribution, with the name
1258 ph10 111 config.h.generic, for the benefit of those who have to compile without
1259     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1260    
1261     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1262     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1263 ph10 127 makevp.bat for the current PCRE, using the additional files
1264 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1265 ph10 111
1266     6. A Windows user reported a minor discrepancy with test 2, which turned out
1267     to be caused by a trailing space on an input line that had got lost in his
1268 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1269 ph10 111
1270 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1271 ph10 111 that is needed.
1272    
1273 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1274     as "const" (a) because they are and (b) because it helps the PHP
1275     maintainers who have recently made a script to detect big data structures
1276 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1277     to update Builducptable as well, so it won't revert if ucptable.h is ever
1278 ph10 105 re-created.
1279 ph10 111
1280     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1281 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1282 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1283     support is not required. This saves 1.5-2K of code, which is important in
1284 ph10 107 some applications.
1285 ph10 111
1286 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1287 ph10 111 so as not to refer to the tables, even though these functions will never be
1288     called when UTF-8 support is disabled. Otherwise there are problems with a
1289     shared library.
1290    
1291 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1292    
1293     (a) It was defining its arguments as char * instead of void *.
1294    
1295 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1296     a long time ago when I wrote it, but is no longer the case.
1297    
1298 ph10 118 The emulated memove() is provided for those environments that have neither
1299 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1300 ph10 118 is clearly not the case, as these two bugs were recently reported.
1301 ph10 123
1302 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1303 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1304     pages, and it removes trailing spaces from listed files. It also creates
1305     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1306     case, it wraps all the #defines with #ifndefs. This script should be run
1307 ph10 111 before "make dist".
1308 ph10 123
1309 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1310     with Unicode property support.
1311 ph10 123
1312     (a) For a maximizing quantifier, if the two different cases of the
1313     character were of different lengths in their UTF-8 codings (there are
1314     some cases like this - I found 11), and the matching function had to
1315 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1316     were both the same length.
1317 ph10 123
1318     (b) When PCRE was configured to use the heap rather than the stack for
1319     recursion during matching, it was not correctly preserving the data for
1320     the other case of a UTF-8 character when checking ahead for a match
1321     while processing a minimizing repeat. If the check also involved
1322 ph10 115 matching a wide character, but failed, corruption could cause an
1323     erroneous result when trying to check for a repeat of the original
1324     character.
1325 ph10 123
1326 ph10 116 13. Some tidying changes to the testing mechanism:
1327 ph10 98
1328 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1329     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1330 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1331     this for UTF-8.) The configure.ac script no longer substitutes the
1332     relevant variables.
1333    
1334 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1335     with length and offset values. This means that the output is different
1336     for different internal link sizes. Test 2 is skipped for link sizes
1337     other than 2 because of this, bypassing the problem. Unfortunately,
1338     there was also a test in test 3 (the locale tests) that used /B and
1339 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1340     I have added a new /Z option to pcretest that replaces the length and
1341     offset values with spaces. This is now used to make test 3 independent
1342 ph10 122 of link size. (Test 2 will be tidied up later.)
1343 ph10 123
1344     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1345 ph10 122 segmentation fault instead of returning the appropriate error message.
1346 ph10 134
1347 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1348 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1349     This doesn't seem right; it now treats the CRLF combination as the line
1350     ending, and so does not match in that case. It's only a pattern such as ^$
1351     that would hit this one: something like ^ABC$ would have failed after \r
1352     and then tried again after \r\n.
1353    
1354 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1355 ph10 134 in an attempt to make files that differ only in their line terminators
1356     compare equal. This works on Linux.
1357 ph10 142
1358 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1359     as it exited. This is now fixed, thanks to valgrind.
1360 ph10 142
1361 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1362 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1363     was because its rules for how to advance for /g after matching an empty
1364 ph10 143 string at the end of a line did not allow for this case. They now check for
1365     it specially.
1366 ph10 150
1367     20. pcretest is supposed to handle patterns and data of any length, by
1368     extending its buffers when necessary. It was getting this wrong when the
1369 ph10 147 buffer for a data line had to be extended.
1370 ph10 150
1371 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1372 ph10 150 CRLF as a newline sequence.
1373 ph10 152
1374 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1375 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1376     I have nevertheless tidied it up.
1377 ph10 111
1378 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1379 ph10 123
1380 ph10 153 24. Added a man page for pcre-config.
1381 ph10 152
1382 ph10 153
1383 nigel 93 Version 7.0 19-Dec-06
1384     ---------------------
1385    
1386     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1387     moving to gcc 4.1.1.
1388    
1389     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1390     sys/time.h, which is documented as needed for this function. It doesn't
1391     seem to matter on Linux, but it showed up on some releases of OS X.
1392    
1393     3. It seems that there are systems where bytes whose values are greater than
1394     127 match isprint() in the "C" locale. The "C" locale should be the
1395     default when a C program starts up. In most systems, only ASCII printing
1396     characters match isprint(). This difference caused the output from pcretest
1397     to vary, making some of the tests fail. I have changed pcretest so that:
1398    
1399     (a) When it is outputting text in the compiled version of a pattern, bytes
1400     other than 32-126 are always shown as hex escapes.
1401    
1402     (b) When it is outputting text that is a matched part of a subject string,
1403     it does the same, unless a different locale has been set for the match
1404     (using the /L modifier). In this case, it uses isprint() to decide.
1405    
1406     4. Fixed a major bug that caused incorrect computation of the amount of memory
1407     required for a compiled pattern when options that changed within the
1408     pattern affected the logic of the preliminary scan that determines the
1409     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1410     that the computed length was too small. The symptoms of this bug were
1411     either the PCRE error "internal error: code overflow" from pcre_compile(),
1412     or a glibc crash with a message such as "pcretest: free(): invalid next
1413     size (fast)". Examples of patterns that provoked this bug (shown in
1414     pcretest format) are:
1415    
1416     /(?-x: )/x
1417     /(?x)(?-x: \s*#\s*)/
1418     /((?i)[\x{c0}])/8
1419     /(?i:[\x{c0}])/8
1420    
1421     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1422     is now done differently.
1423    
1424     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1425     wrapper classes; (b) implement a new function in the C++ scanner that is
1426     more efficient than the old way of doing things because it avoids levels of
1427     recursion in the regex matching; (c) add a paragraph to the documentation
1428     for the FullMatch() function.
1429    
1430     6. The escape sequence \n was being treated as whatever was defined as
1431     "newline". Not only was this contrary to the documentation, which states
1432     that \n is character 10 (hex 0A), but it also went horribly wrong when
1433     "newline" was defined as CRLF. This has been fixed.
1434    
1435     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1436     was being set to -1 for the "end of line" case (supposedly a value that no
1437     character can have). Though this value is never used (the check for end of
1438     line is "zero bytes in current character"), it caused compiler complaints.
1439     I've changed it to 0xffffffff.
1440    
1441     8. In pcre_version.c, the version string was being built by a sequence of
1442     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1443     string (as it is for production releases) called a macro with an empty
1444     argument. The C standard says the result of this is undefined. The gcc
1445     compiler treats it as an empty string (which was what was wanted) but it is
1446     reported that Visual C gives an error. The source has been hacked around to
1447     avoid this problem.
1448    
1449     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1450     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1451     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1452     of them did).
1453    
1454     10. Originally, pcretest opened its input and output without "b"; then I was
1455     told that "b" was needed in some environments, so it was added for release
1456     5.0 to both the input and output. (It makes no difference on Unix-like
1457     systems.) Later I was told that it is wrong for the input on Windows. I've
1458     now abstracted the modes into two macros, to make it easier to fiddle with
1459     them, and removed "b" from the input mode under Windows.
1460    
1461     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1462    
1463     12. Added -help and --help to pcretest as an official way of being reminded
1464     of the options.
1465    
1466     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1467     and pcrecpp.cc because they annoy compilers at high warning levels.
1468    
1469     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1470    
1471     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1472     scripts are not C programs :-) and which was not noticed because it works
1473     on Linux.
1474    
1475     16. pcretest is supposed to handle any length of pattern and data line (as one
1476     line or as a continued sequence of lines) by extending its input buffer if
1477     necessary. This feature was broken for very long pattern lines, leading to
1478     a string of junk being passed to pcre_compile() if the pattern was longer
1479     than about 50K.
1480    
1481     17. I have done a major re-factoring of the way pcre_compile() computes the
1482     amount of memory needed for a compiled pattern. Previously, there was code
1483     that made a preliminary scan of the pattern in order to do this. That was
1484     OK when PCRE was new, but as the facilities have expanded, it has become
1485     harder and harder to keep it in step with the real compile phase, and there
1486     have been a number of bugs (see for example, 4 above). I have now found a
1487     cunning way of running the real compile function in a "fake" mode that
1488     enables it to compute how much memory it would need, while actually only
1489     ever using a few hundred bytes of working memory and without too many
1490     tests of the mode. This should make future maintenance and development
1491     easier. A side effect of this work is that the limit of 200 on the nesting
1492     depth of parentheses has been removed (though this was never a serious
1493     limitation, I suspect). However, there is a downside: pcre_compile() now
1494     runs more slowly than before (30% or more, depending on the pattern). I
1495     hope this isn't a big issue. There is no effect on runtime performance.
1496    
1497     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1498     newline (only possible for the last line of a file) and it was a
1499     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1500    
1501     19. Added additional timing features to pcretest. (1) The -tm option now times
1502     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1503     separate command line item, by a number that specifies the number of
1504     repeats to use when timing. The default is 50000; this gives better
1505     precision, but takes uncomfortably long for very large patterns.
1506    
1507     20. Extended pcre_study() to be more clever in cases where a branch of a
1508     subpattern has no definite first character. For example, (a*|b*)[cd] would
1509     previously give no result from pcre_study(). Now it recognizes that the
1510     first character must be a, b, c, or d.
1511    
1512     21. There was an incorrect error "recursive call could loop indefinitely" if
1513     a subpattern (or the entire pattern) that was being tested for matching an
1514     empty string contained only one non-empty item after a nested subpattern.
1515     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1516     incorrectly, because the \d was being skipped in the check.
1517    
1518     22. The pcretest program now has a new pattern option /B and a command line
1519     option -b, which is equivalent to adding /B to every pattern. This causes
1520     it to show the compiled bytecode, without the additional information that
1521     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1522     is the same as /B/I).
1523    
1524     23. A new optimization is now able automatically to treat some sequences such
1525     as a*b as a*+b. More specifically, if something simple (such as a character
1526     or a simple class like \d) has an unlimited quantifier, and is followed by
1527     something that cannot possibly match the quantified thing, the quantifier
1528     is automatically "possessified".
1529    
1530     24. A recursive reference to a subpattern whose number was greater than 39
1531     went wrong under certain circumstances in UTF-8 mode. This bug could also
1532     have affected the operation of pcre_study().
1533    
1534     25. Realized that a little bit of performance could be had by replacing
1535     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1536    
1537     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1538    
1539     27. Possessive quantifiers such as a++ were previously implemented by turning
1540     them into atomic groups such as ($>a+). Now they have their own opcodes,
1541     which improves performance. This includes the automatically created ones
1542     from 23 above.
1543    
1544     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1545     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1546     the first matched character to be a colon. This applied both to named and
1547     numbered groups.
1548    
1549     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1550    
1551     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1552     building PCRE on Windows easier, so I have included it in the distribution.
1553    
1554     31. There is now a check in pcretest against a ridiculously large number being
1555     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1556     loop, the loop is abandoned.
1557    
1558     32. Forward references to subpatterns in conditions such as (?(2)...) where
1559     subpattern 2 is defined later cause pcre_compile() to search forwards in
1560     the pattern for the relevant set of parentheses. This search went wrong
1561     when there were unescaped parentheses in a character class, parentheses
1562     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1563    
1564     33. "Subroutine" calls and backreferences were previously restricted to
1565     referencing subpatterns earlier in the regex. This restriction has now
1566     been removed.
1567    
1568     34. Added a number of extra features that are going to be in Perl 5.10. On the
1569     whole, these are just syntactic alternatives for features that PCRE had
1570     previously implemented using the Python syntax or my own invention. The
1571     other formats are all retained for compatibility.
1572    
1573     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1574     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1575     also .NET compatible.
1576    
1577     (b) A recursion or subroutine call to a named group can now be defined as
1578     (?&name) as well as (?P>name).
1579    
1580     (c) A backreference to a named group can now be defined as \k<name> or
1581     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1582     5.10, are also .NET compatible.
1583    
1584     (d) A conditional reference to a named group can now use the syntax
1585     (?(<name>) or (?('name') as well as (?(name).
1586    
1587     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1588     groups (named and numbered) that are never evaluated inline, but can be
1589     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1590     is always false. There may be only one alternative in such a group.
1591    
1592     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1593     as the simple (?(R). The condition is true only if the most recent
1594     recursion is that of the given number or name. It does not search out
1595     through the entire recursion stack.
1596    
1597     (g) The escape \gN or \g{N} has been added, where N is a positive or
1598     negative number, specifying an absolute or relative reference.
1599    
1600     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1601     some "unreachable code" warnings.
1602    
1603     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1604     things, this adds five new scripts.
1605    
1606     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1607     There were also incompatibilities regarding the handling of \Q..\E inside
1608     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1609     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1610    
1611     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1612     matches an empty string, and forcibly breaks the loop. There were bugs in
1613     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1614     against aaaa the result was just "a" rather than "aaaa", for example. Two
1615     separate and independent bugs (that affected different cases) have been
1616     fixed.
1617    
1618     39. Refactored the code to abolish the use of different opcodes for small
1619     capturing bracket numbers. This is a tidy that I avoided doing when I
1620     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1621     The new approach is not only tidier, it makes it possible to reduce the
1622     memory needed to fix the previous bug (38).
1623    
1624     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1625     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1626     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1627     mode.
1628    
1629     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1630     report.
1631    
1632     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1633     copy construction and assignment in the C++ wrapper.
1634    
1635     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1636     couple of bugs that could have given wrong results in the "--newline=crlf"
1637     case.
1638    
1639     44. Added a number of casts and did some reorganization of signed/unsigned int
1640     variables following suggestions from Dair Grant. Also renamed the variable
1641     "this" as "item" because it is a C++ keyword.
1642    
1643     45. Arranged for dftables to add
1644    
1645     #include "pcre_internal.h"
1646    
1647     to pcre_chartables.c because without it, gcc 4.x may remove the array
1648     definition from the final binary if PCRE is built into a static library and
1649     dead code stripping is activated.
1650    
1651     46. For an unanchored pattern, if a match attempt fails at the start of a
1652     newline sequence, and the newline setting is CRLF or ANY, and the next two
1653     characters are CRLF, advance by two characters instead of one.
1654    
1655    
1656 nigel 91 Version 6.7 04-Jul-06
1657     ---------------------
1658    
1659     1. In order to handle tests when input lines are enormously long, pcretest has
1660     been re-factored so that it automatically extends its buffers when
1661     necessary. The code is crude, but this _is_ just a test program. The
1662     default size has been increased from 32K to 50K.
1663    
1664     2. The code in pcre_study() was using the value of the re argument before
1665     testing it for NULL. (Of course, in any sensible call of the function, it
1666     won't be NULL.)
1667    
1668     3. The memmove() emulation function in pcre_internal.h, which is used on
1669     systems that lack both memmove() and bcopy() - that is, hardly ever -
1670     was missing a "static" storage class specifier.
1671    
1672     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1673     containing an extended class (one that cannot be represented by a bitmap
1674     because it contains high-valued characters or Unicode property items, e.g.
1675     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1676     pattern, but PCRE should not loop if you do not (it no longer does).
1677     [Detail: two cases were found: (a) a repeated subpattern containing an
1678     extended class; (b) a recursive reference to a subpattern that followed a
1679     previous extended class. It wasn't skipping over the extended class
1680     correctly when UTF-8 mode was not set.]
1681    
1682     5. A negated single-character class was not being recognized as fixed-length
1683     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1684     compile error "lookbehind assertion is not fixed length".
1685    
1686     6. The RunPerlTest auxiliary script was showing an unexpected difference
1687     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1688     write a Perl script that can interpret lines of an input file either as
1689     byte characters or as UTF-8, which is what "perltest" was being required to
1690     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1691     can't do is switch easily at run time between having the "use utf8;" pragma
1692     or not. In the end, I fudged it by using the RunPerlTest script to insert
1693     "use utf8;" explicitly for the UTF-8 tests.
1694    
1695     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1696     the end of the subject string, contrary to the documentation and to what
1697     Perl does. This was true of both matching functions. Now it matches only at
1698     the start of the subject and immediately after *internal* newlines.
1699    
1700     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1701     a pointer to an int instead of a pointer to an unsigned long int. This
1702     caused problems on 64-bit systems.
1703    
1704     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1705     instance of the 'standard' template library not being so standard".
1706    
1707     10. There was no check on the number of named subpatterns nor the maximum
1708     length of a subpattern name. The product of these values is used to compute
1709     the size of the memory block for a compiled pattern. By supplying a very
1710     long subpattern name and a large number of named subpatterns, the size
1711     computation could be caused to overflow. This is now prevented by limiting
1712     the length of names to 32 characters, and the number of named subpatterns
1713     to 10,000.
1714    
1715     11. Subpatterns that are repeated with specific counts have to be replicated in
1716     the compiled pattern. The size of memory for this was computed from the
1717     length of the subpattern and the repeat count. The latter is limited to
1718     65535, but there was no limit on the former, meaning that integer overflow
1719     could in principle occur. The compiled length of a repeated subpattern is
1720     now limited to 30,000 bytes in order to prevent this.
1721    
1722     12. Added the optional facility to have named substrings with the same name.
1723    
1724     13. Added the ability to use a named substring as a condition, using the
1725     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1726     are numbers (not recommended). Forward references are permitted.
1727    
1728     14. Added forward references in named backreferences (if you see what I mean).
1729    
1730     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1731     pattern could run off the end of the subject. For example, the pattern
1732     "(?s)(.{1,5})"8 did this with the subject "ab".
1733    
1734     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1735     PCRE_CASELESS was set when matching characters that were quantified with ?
1736     or *.
1737    
1738     17. A character class other than a single negated character that had a minimum
1739     but no maximum quantifier - for example [ab]{6,} - was not handled
1740     correctly by pce_dfa_exec(). It would match only one character.
1741    
1742     18. A valid (though odd) pattern that looked like a POSIX character
1743     class but used an invalid character after [ (for example [[,abc,]]) caused
1744     pcre_compile() to give the error "Failed: internal error: code overflow" or
1745     in some cases to crash with a glibc free() error. This could even happen if
1746     the pattern terminated after [[ but there just happened to be a sequence of
1747     letters, a binary zero, and a closing ] in the memory that followed.
1748    
1749     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1750     over the years. Originally (before any Unicode support), just the bottom 8
1751     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1752     output from "man perlunicode" includes this:
1753    
1754     The regular expression compiler produces polymorphic opcodes. That
1755     is, the pattern adapts to the data and automatically switches to
1756     the Unicode character scheme when presented with Unicode data--or
1757     instead uses a traditional byte scheme when presented with byte
1758     data.
1759    
1760     Sadly, a wide octal escape does not cause a switch, and in a string with
1761     no other multibyte characters, these octal escapes are treated as before.
1762     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1763     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1764     Unicode string.
1765    
1766     I have not perpetrated such confusion in PCRE. Up till now, it took just
1767     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1768     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1769     translate to the appropriate multibyte character.
1770    
1771     29. Applied some refactoring to reduce the number of warnings from Microsoft
1772     and Borland compilers. This has included removing the fudge introduced
1773     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1774     a warning about an unused variable.
1775    
1776     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1777     characters since release 4.0, because Perl (from release 5.004) does not.
1778     [Or at least, is documented not to: some releases seem to be in conflict
1779     with the documentation.] However, when a pattern was studied with
1780     pcre_study() and all its branches started with \s, PCRE still included VT
1781     as a possible starting character. Of course, this did no harm; it just
1782     caused an unnecessary match attempt.
1783    
1784     22. Removed a now-redundant internal flag bit that recorded the fact that case
1785     dependency changed within the pattern. This was once needed for "required
1786     byte" processing, but is no longer used. This recovers a now-scarce options
1787     bit. Also moved the least significant internal flag bit to the most-
1788     significant bit of the word, which was not previously used (hangover from
1789     the days when it was an int rather than a uint) to free up another bit for
1790     the future.
1791    
1792     23. Added support for CRLF line endings as well as CR and LF. As well as the
1793     default being selectable at build time, it can now be changed at runtime
1794     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1795     specify that it is scanning data with non-default line endings.
1796    
1797     24. Changed the definition of CXXLINK to make it agree with the definition of
1798     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1799    
1800     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1801     recursions. This makes a big different to stack usage for some patterns.
1802    
1803     26. If a subpattern containing a named recursion or subroutine reference such
1804     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1805     the space required for the compiled pattern went wrong and gave too small a
1806     value. Depending on the environment, this could lead to "Failed: internal
1807     error: code overflow at offset 49" or "glibc detected double free or
1808     corruption" errors.
1809    
1810     27. Applied patches from Google (a) to support the new newline modes and (b) to
1811     advance over multibyte UTF-8 characters in GlobalReplace.
1812    
1813     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1814     difference for some implementation of PCRE in some Windows version.
1815    
1816     29. Added some extra testing facilities to pcretest:
1817    
1818     \q<number> in a data line sets the "match limit" value
1819     \Q<number> in a data line sets the "match recursion limt" value
1820     -S <number> sets the stack size, where <number> is in megabytes
1821    
1822     The -S option isn't available for Windows.
1823    
1824    
1825 nigel 89 Version 6.6 06-Feb-06
1826     ---------------------
1827    
1828     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1829     in pcreposix.h. I have copied the definition from pcre.h.
1830    
1831     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1832     because pcre.h is no longer a built file.
1833    
1834     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1835     not normally included in the compiled code.
1836    
1837    
1838 nigel 87 Version 6.5 01-Feb-06
1839     ---------------------
1840    
1841     1. When using the partial match feature with pcre_dfa_exec(), it was not
1842     anchoring the second and subsequent partial matches at the new starting
1843     point. This could lead to incorrect results. For example, with the pattern
1844     /1234/, partially matching against "123" and then "a4" gave a match.
1845    
1846     2. Changes to pcregrep:
1847    
1848     (a) All non-match returns from pcre_exec() were being treated as failures
1849     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1850     error message is output. Some extra information is given for the
1851     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1852     probably the only errors that are likely to be caused by users (by
1853     specifying a regex that has nested indefinite repeats, for instance).
1854     If there are more than 20 of these errors, pcregrep is abandoned.
1855    
1856     (b) A binary zero was treated as data while matching, but terminated the
1857     output line if it was written out. This has been fixed: binary zeroes
1858     are now no different to any other data bytes.
1859    
1860     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1861     used to set a locale for matching. The --locale=xxxx long option has
1862     been added (no short equivalent) to specify a locale explicitly on the
1863     pcregrep command, overriding the environment variables.
1864    
1865     (d) When -B was used with -n, some line numbers in the output were one less
1866     than they should have been.
1867    
1868     (e) Added the -o (--only-matching) option.
1869    
1870     (f) If -A or -C was used with -c (count only), some lines of context were
1871     accidentally printed for the final match.
1872    
1873     (g) Added the -H (--with-filename) option.
1874    
1875     (h) The combination of options -rh failed to suppress file names for files
1876     that were found from directory arguments.
1877    
1878     (i) Added the -D (--devices) and -d (--directories) options.
1879    
1880     (j) Added the -F (--fixed-strings) option.
1881    
1882     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1883    
1884     (l) Added the --colo(u)r option.
1885    
1886     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1887     is not present by default.
1888    
1889     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1890     items such as (?R) or (?1), when the recursion could match a number of
1891     alternatives. If it matched one of the alternatives, but subsequently,
1892     outside the recursion, there was a failure, the code tried to back up into
1893     the recursion. However, because of the way PCRE is implemented, this is not
1894     possible, and the result was an incorrect result from the match.
1895    
1896     In order to prevent this happening, the specification of recursion has
1897     been changed so that all such subpatterns are automatically treated as
1898     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1899    
1900     4. I had overlooked the fact that, in some locales, there are characters for
1901     which isalpha() is true but neither isupper() nor islower() are true. In
1902     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1903     and ordfeminine) are like this. This affected the treatment of \w and \W
1904     when they appeared in character classes, but not when they appeared outside
1905     a character class. The bit map for "word" characters is now created
1906     separately from the results of isalnum() instead of just taking it from the
1907     upper, lower, and digit maps. (Plus the underscore character, of course.)
1908    
1909     5. The above bug also affected the handling of POSIX character classes such as
1910     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1911     permanent tables. Instead, the bit maps for such a class were previously
1912     created as the appropriate unions of the upper, lower, and digit bitmaps.
1913     Now they are created by subtraction from the [[:word:]] class, which has
1914     its own bitmap.
1915    
1916     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1917     It is created by subtracting the vertical space characters (\x09, \x0a,
1918     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1919     subtraction was done in the overall bitmap for a character class, meaning
1920     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1921     be recognized. This bug has been fixed.
1922    
1923     7. Patches from the folks at Google:
1924    
1925     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1926     real life, but is still worth protecting against".
1927    
1928     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1929     regular expressions".
1930    
1931     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1932     have it.
1933    
1934     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1935     "configure" and the latter not, in order to fix a problem somebody had
1936     with compiling the Arg class on HP-UX.
1937    
1938     (e) Improve the error-handling of the C++ wrapper a little bit.
1939    
1940     (f) New tests for checking recursion limiting.
1941    
1942     8. The pcre_memmove() function, which is used only if the environment does not
1943     have a standard memmove() function (and is therefore rarely compiled),
1944     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1945     returning a result (though PCRE never actually uses the result).
1946    
1947     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1948     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1949     returned instead of calling malloc() with an overflowing number that would
1950     most likely cause subsequent chaos.
1951    
1952     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1953    
1954     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1955     with this option is matched, the nmatch and pmatch options of regexec() are
1956     ignored.
1957    
1958     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1959     provided in case anyone wants to the the POSIX interface with UTF-8
1960     strings.
1961    
1962     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1963     C++ linking (needed for some HP-UX environments).
1964    
1965     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1966     (unused parameter) and in the pcre_printint() function (omitted "default"
1967     switch label when the default is to do nothing).
1968    
1969     15. Added some code to make it possible, when PCRE is compiled as a C++
1970     library, to replace subject pointers for pcre_exec() with a smart pointer
1971     class, thus making it possible to process discontinuous strings.
1972    
1973     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1974     much the same function. They were added by different people who were trying
1975     to make PCRE easy to compile on non-Unix systems. It has been suggested
1976     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1977     for compiling on Windows systems. I have therefore replaced it with
1978     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1979     defaults to "extern" for C or "extern C" for C++, which works fine on
1980     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1981     SCOPE with something explicit in config.h. In addition:
1982    
1983     (a) pcreposix.h still had just "extern" instead of either of these macros;
1984     I have replaced it with PCRE_DATA_SCOPE.
1985    
1986     (b) Functions such as _pcre_xclass(), which are internal to the library,
1987     but external in the C sense, all had PCRE_EXPORT in their definitions.
1988     This is apparently wrong for the Windows case, so I have removed it.
1989     (It makes no difference on Unix-like systems.)
1990    
1991     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1992     of recursive calls to match(). This is different to MATCH_LIMIT because
1993     that limits the total number of calls to match(), not all of which increase
1994     the depth of recursion. Limiting the recursion depth limits the amount of
1995     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1996     when PCRE is compiled, and changed at run time. A patch from Google adds
1997     this functionality to the C++ interface.
1998    
1999     18. Changes to the handling of Unicode character properties:
2000    
2001     (a) Updated the table to Unicode 4.1.0.
2002    
2003     (b) Recognize characters that are not in the table as "Cn" (undefined).
2004    
2005     (c) I revised the way the table is implemented to a much improved format
2006     which includes recognition of ranges. It now supports the ranges that
2007     are defined in UnicodeData.txt, and it also amalgamates other
2008     characters into ranges. This has reduced the number of entries in the
2009     table from around 16,000 to around 3,000, thus reducing its size
2010     considerably. I realized I did not need to use a tree structure after
2011     all - a binary chop search is just as efficient. Having reduced the
2012     number of entries, I extended their size from 6 bytes to 8 bytes to
2013     allow for more data.
2014    
2015     (d) Added support for Unicode script names via properties such as \p{Han}.
2016    
2017     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2018     matching that character.
2019    
2020     20. When matching a repeated Unicode property with a minimum greater than zero,
2021     (for example \pL{2,}), PCRE could look past the end of the subject if it
2022     reached it while seeking the minimum number of characters. This could
2023     happen only if some of the characters were more than one byte long, because
2024     there is a check for at least the minimum number of bytes.
2025    
2026     21. Refactored the implementation of \p and \P so as to be more general, to
2027     allow for more different types of property in future. This has changed the
2028     compiled form incompatibly. Anybody with saved compiled patterns that use
2029     \p or \P will have to recompile them.
2030    
2031     22. Added "Any" and "L&" to the supported property types.
2032    
2033     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2034     but give a compile time error if the value is greater than 0xff.
2035    
2036     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2037     accidentally not being installed or uninstalled.
2038    
2039     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2040     made were to insert the current release number. This seemed silly, because
2041     it made things harder for people building PCRE on systems that don't run
2042     "configure". I have turned pcre.h into a distributed file, no longer built
2043     by "configure", with the version identification directly included. There is
2044     no longer a pcre.h.in file.
2045    
2046     However, this change necessitated a change to the pcre-config script as
2047     well. It is built from pcre-config.in, and one of the substitutions was the
2048     release number. I have updated configure.ac so that ./configure now finds
2049     the release number by grepping pcre.h.
2050    
2051     26. Added the ability to run the tests under valgrind.
2052    
2053    
2054 nigel 85 Version 6.4 05-Sep-05
2055     ---------------------
2056    
2057     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2058     "--" to be printed when multiple files were scanned, even when none of the
2059     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2060     consider it to be a bug, and have restored the previous behaviour.
2061    
2062     2. A couple of code tidies to get rid of compiler warnings.
2063    
2064     3. The pcretest program used to cheat by referring to symbols in the library
2065     whose names begin with _pcre_. These are internal symbols that are not
2066     really supposed to be visible externally, and in some environments it is
2067     possible to suppress them. The cheating is now confined to including
2068     certain files from the library's source, which is a bit cleaner.
2069    
2070     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2071     file's purpose clearer.
2072    
2073     5. Reorganized pcre_ucp_findchar().
2074    
2075    
2076 nigel 83 Version 6.3 15-Aug-05
2077     ---------------------
2078    
2079     1. The file libpcre.pc.in did not have general read permission in the tarball.
2080    
2081     2. There were some problems when building without C++ support:
2082    
2083     (a) If C++ support was not built, "make install" and "make test" still
2084     tried to test it.
2085    
2086     (b) There were problems when the value of CXX was explicitly set. Some
2087     changes have been made to try to fix these, and ...
2088    
2089     (c) --disable-cpp can now be used to explicitly disable C++ support.
2090    
2091     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2092     backslash in a target when C++ was disabled. This confuses some
2093     versions of "make", apparently. Using an intermediate variable solves
2094     this. (Same for CPP_LOBJ.)
2095    
2096     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2097     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2098     necessary on certain architectures.
2099    
2100     4. Added a setting of -export-symbols-regex to the link command to remove
2101     those symbols that are exported in the C sense, but actually are local
2102     within the library, and not documented. Their names all begin with
2103     "_pcre_". This is not a perfect job, because (a) we have to except some
2104     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2105     available (and never for static libraries). I have made a note to try to
2106     find a way round (a) in the future.
2107    
2108    
2109 nigel 81 Version 6.2 01-Aug-05
2110     ---------------------
2111    
2112     1. There was no test for integer overflow of quantifier values. A construction
2113     such as {1111111111111111} would give undefined results. What is worse, if
2114     a minimum quantifier for a parenthesized subpattern overflowed and became
2115     negative, the calculation of the memory size went wrong. This could have
2116     led to memory overwriting.
2117    
2118     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2119    
2120     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2121     operating environments where this matters.
2122    
2123     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2124     PCRE options from within the C++ wrapper.
2125    
2126     5. Named capturing subpatterns were not being correctly counted when a pattern
2127     was compiled. This caused two problems: (a) If there were more than 100
2128     such subpatterns, the calculation of the memory needed for the whole
2129     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2130     back references of the form \12, where the number was greater than 9, were
2131     not recognized as back references, even though there were sufficient
2132     previous subpatterns.
2133    
2134     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2135     versions of gcc, e.g. 2.95.4.
2136    
2137    
2138 nigel 79 Version 6.1 21-Jun-05
2139     ---------------------
2140    
2141     1. There was one reference to the variable "posix" in pcretest.c that was not
2142     surrounded by "#if !defined NOPOSIX".
2143    
2144     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2145     the cross-check on the old pcre_info() function, for the benefit of the
2146     cut-down version of PCRE that is currently imported into Exim.
2147    
2148     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2149     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2150     patterns that start (?i) but I don't think that matters. The use of (?i) is
2151     just an example; this all applies to the other options as well.
2152    
2153     4. Since libtool seems to echo the compile commands it is issuing, the output
2154     from "make" can be reduced a bit by putting "@" in front of each libtool
2155     compile command.
2156    
2157     5. Patch from the folks at Google for configure.in to be a bit more thorough
2158     in checking for a suitable C++ installation before trying to compile the
2159     C++ stuff. This should fix a reported problem when a compiler was present,
2160     but no suitable headers.
2161    
2162     6. The man pages all had just "PCRE" as their title. I have changed them to
2163     be the relevant file name. I have also arranged that these names are
2164     retained in the file doc/pcre.txt, which is a concatenation in text format
2165     of all the man pages except the little individual ones for each function.
2166    
2167     7. The NON-UNIX-USE file had not been updated for the different set of source
2168     files that come with release 6. I also added a few comments about the C++
2169     wrapper.
2170    
2171    
2172 nigel 77 Version 6.0 07-Jun-05
2173     ---------------------
2174    
2175     1. Some minor internal re-organization to help with my DFA experiments.
2176    
2177     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2178     didn't matter for the library itself when fully configured, but did matter
2179     when compiling without UCP support, or within Exim, where the ucp files are
2180     not imported.
2181    
2182     3. Refactoring of the library code to split up the various functions into
2183     different source modules. The addition of the new DFA matching code (see
2184     below) to a single monolithic source would have made it really too
2185     unwieldy, quite apart from causing all the code to be include in a
2186     statically linked application, when only some functions are used. This is
2187     relevant even without the DFA addition now that patterns can be compiled in
2188     one application and matched in another.
2189    
2190     The downside of splitting up is that there have to be some external
2191     functions and data tables that are used internally in different modules of
2192     the library but which are not part of the API. These have all had their
2193     names changed to start with "_pcre_" so that they are unlikely to clash
2194     with other external names.
2195    
2196     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2197     a different (DFA) algorithm. Although it is slower than the original
2198     function, it does have some advantages for certain types of matching
2199     problem.
2200    
2201     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2202     including restarting after a partial match.
2203    
2204     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2205     defined when compiling for Windows was sent to me. I have put it into the
2206     code, though I have no means of testing or verifying it.
2207    
2208     7. Added the pcre_refcount() auxiliary function.
2209    
2210     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2211     match before or at the first newline in the subject string. In pcretest,
2212     the /f option on a pattern can be used to set this.
2213    
2214     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2215     would behave wrongly. This has been present in PCRE since release 4.0.
2216    
2217     10. A number of changes to the pcregrep command:
2218    
2219     (a) Refactored how -x works; insert ^(...)$ instead of setting
2220     PCRE_ANCHORED and checking the length, in preparation for adding
2221     something similar for -w.
2222    
2223     (b) Added the -w (match as a word) option.
2224    
2225     (c) Refactored the way lines are read and buffered so as to have more
2226     than one at a time available.
2227    
2228     (d) Implemented a pcregrep test script.
2229    
2230     (e) Added the -M (multiline match) option. This allows patterns to match
2231     over several lines of the subject. The buffering ensures that at least
2232     8K, or the rest of the document (whichever is the shorter) is available
2233     for matching (and similarly the previous 8K for lookbehind assertions).
2234    
2235     (f) Changed the --help output so that it now says
2236    
2237     -w, --word-regex(p)
2238    
2239     instead of two lines, one with "regex" and the other with "regexp"
2240     because that confused at least one person since the short forms are the
2241     same. (This required a bit of code, as the output is generated
2242     automatically from a table. It wasn't just a text change.)
2243    
2244     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2245     option but starts with a hyphen. Could be a pattern or a path name
2246     starting with a hyphen, for instance.
2247    
2248     (h) "-" can be given as a file name to represent stdin.
2249    
2250     (i) When file names are being printed, "(standard input)" is used for
2251     the standard input, for compatibility with GNU grep. Previously
2252     "<stdin>" was used.
2253    
2254     (j) The option --label=xxx can be used to supply a name to be used for
2255     stdin when file names are being printed. There is no short form.
2256    
2257     (k) Re-factored the options decoding logic because we are going to add
2258     two more options that take data. Such options can now be given in four
2259     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2260    
2261     (l) Added the -A, -B, and -C options for requesting that lines of context
2262     around matches be printed.
2263    
2264     (m) Added the -L option to print the names of files that do not contain
2265     any matching lines, that is, the complement of -l.
2266    
2267     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2268     continue to scan other files.
2269    
2270     (o) The -s option was incorrectly implemented. For compatibility with other
2271     greps, it now suppresses the error message for a non-existent or non-
2272     accessible file (but not the return code). There is a new option called
2273     -q that suppresses the output of matching lines, which was what -s was
2274     previously doing.
2275    
2276     (p) Added --include and --exclude options to specify files for inclusion
2277     and exclusion when recursing.
2278    
2279     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2280     Hopefully, it now does.
2281    
2282     12. Missing cast in pcre_study().
2283    
2284     13. Added an "uninstall" target to the makefile.
2285    
2286     14. Replaced "extern" in the function prototypes in Makefile.in with
2287     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2288     world, but is set differently for Windows.
2289    
2290     15. Added a second compiling function called pcre_compile2(). The only
2291     difference is that it has an extra argument, which is a pointer to an
2292     integer error code. When there is a compile-time failure, this is set
2293     non-zero, in addition to the error test pointer being set to point to an
2294     error message. The new argument may be NULL if no error number is required
2295     (but then you may as well call pcre_compile(), which is now just a
2296     wrapper). This facility is provided because some applications need a
2297     numeric error indication, but it has also enabled me to tidy up the way
2298     compile-time errors are handled in the POSIX wrapper.
2299    
2300     16. Added VPATH=.libs to the makefile; this should help when building with one
2301     prefix path and installing with another. (Or so I'm told by someone who
2302     knows more about this stuff than I do.)
2303    
2304     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2305     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2306     match everything, including newlines. This is not POSIX-compatible, but
2307     somebody wanted the feature. From pcretest it can be activated by using
2308     both the P and the s flags.
2309    
2310     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2311    
2312     19. libpcre.pc was being incorrectly installed as executable.
2313    
2314     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2315     it now also looks for '\r' so that it will work unmodified on Windows.
2316    
2317     21. Added Google's contributed C++ wrapper to the distribution.
2318    
2319     22. Added some untidy missing memory free() calls in pcretest, to keep
2320     Electric Fence happy when testing.
2321    
2322    
2323    
2324 nigel 75 Version 5.0 13-Sep-04
2325     ---------------------
2326    
2327     1. Internal change: literal characters are no longer packed up into items
2328     containing multiple characters in a single byte-string. Each character
2329     is now matched using a separate opcode. However, there may be more than one
2330     byte in the character in UTF-8 mode.
2331    
2332     2. The pcre_callout_block structure has two new fields: pattern_position and
2333     next_item_length. These contain the offset in the pattern to the next match
2334     item, and its length, respectively.
2335    
2336     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2337     insertion of callouts before each pattern item. Added the /C option to
2338     pcretest to make use of this.
2339    
2340     4. On the advice of a Windows user, the lines
2341    
2342     #if defined(_WIN32) || defined(WIN32)
2343     _setmode( _fileno( stdout ), 0x8000 );
2344     #endif /* defined(_WIN32) || defined(WIN32) */
2345    
2346     have been added to the source of pcretest. This apparently does useful
2347     magic in relation to line terminators.
2348    
2349     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2350     for the benefit of those environments where the "b" makes a difference.
2351    
2352     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2353     to know about it. I have put a hack into configure.in that adds in code
2354     to set GCC=yes if CC=icc. This seems to end up at a point in the
2355     generated configure script that is early enough to affect the setting of
2356     compiler options, which is what is needed, but I have no means of testing
2357     whether it really works. (The user who reported this had patched the
2358     generated configure script, which of course I cannot do.)
2359    
2360     LATER: After change 22 below (new libtool files), the configure script
2361     seems to know about icc (and also ecc). Therefore, I have commented out
2362     this hack in configure.in.
2363    
2364     7. Added support for pkg-config (2 patches were sent in).
2365    
2366     8. Negated POSIX character classes that used a combination of internal tables
2367     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2368     [[:^ascii]]. Typically, they would match almost any characters. The other
2369     POSIX classes were not broken in this way.
2370    
2371     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2372     to find the match, as PCRE was deluded into thinking that the match had to
2373     start at the start point or following a newline. The same bug applied to
2374     patterns with negative forward assertions or any backward assertions
2375     preceding ".*" at the start, unless the pattern required a fixed first
2376     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2377    
2378     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2379     starting at the last subject character, bytes beyond the end of the subject
2380     string were read.
2381    
2382     11. Renamed the variable "class" as "classbits" to make life easier for C++
2383     users. (Previously there was a macro definition, but it apparently wasn't
2384     enough.)
2385    
2386     12. Added the new field "tables" to the extra data so that tables can be passed
2387     in at exec time, or the internal tables can be re-selected. This allows
2388     a compiled regex to be saved and re-used at a later time by a different
2389     program that might have everything at different addresses.
2390    
2391     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2392     -R library as well as a -L library.
2393    
2394     14. The debugging options of pcretest (-d on the command line or D on a
2395     pattern) showed incorrect output for anything following an extended class
2396     that contained multibyte characters and which was followed by a quantifier.
2397    
2398     15. Added optional support for general category Unicode character properties
2399     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2400     support. It adds about 90K to the size of the library. The meanings of the
2401     inbuilt class escapes such as \d and \s have NOT been changed.
2402    
2403     16. Updated pcredemo.c to include calls to free() to release the memory for the
2404     compiled pattern.
2405    
2406     17. The generated file chartables.c was being created in the source directory
2407     instead of in the building directory. This caused the build to fail if the
2408     source directory was different from the building directory, and was
2409     read-only.
2410    
2411     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2412     file. No doubt somebody will tell me if they don't make sense... Also added
2413     Dan Mooney's comments about building on OpenVMS.
2414    
2415     19. Added support for partial matching via the PCRE_PARTIAL option for
2416     pcre_exec() and the \P data escape in pcretest.
2417    
2418     20. Extended pcretest with 3 new pattern features:
2419    
2420     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2421     write the compiled pattern to the file whose name is "rest-of-line".
2422     This is a straight binary dump of the data, with the saved pointer to
2423     the character tables forced to be NULL. The study data, if any, is
2424     written too. After writing, pcretest reads a new pattern.
2425    
2426     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2427     compiled pattern from the given file. There must not be any
2428     occurrences of "<" in the file name (pretty unlikely); if there are,
2429     pcretest will instead treat the initial "<" as a pattern delimiter.
2430     After reading in the pattern, pcretest goes on to read data lines as
2431     usual.
2432    
2433     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2434     and 16-bit fields in a compiled pattern, to simulate a pattern that
2435     was compiled on a host of opposite endianness.
2436    
2437     21. The pcre-exec() function can now cope with patterns that were compiled on
2438     hosts of opposite endianness, with this restriction:
2439    
2440     As for any compiled expression that is saved and used later, the tables
2441     pointer field cannot be preserved; the extra_data field in the arguments
2442     to pcre_exec() should be used to pass in a tables address if a value
2443     other than the default internal tables were used at compile time.
2444    
2445     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2446     now diagnosed as an error. Previously, most of the time, a negative number
2447     would have been treated as zero, but if in addition "ovector" was passed as
2448     NULL, a crash could occur.
2449    
2450     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2451     new versions from the libtool 1.5 distribution (the last one is a copy of
2452     a file called libtool.m4). This seems to have fixed the need to patch
2453     "configure" to support Darwin 1.3 (which I used to do). However, I still
2454     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2455     workstation).
2456    
2457     24. Changed the PCRE licence to be the more standard "BSD" licence.
2458    
2459    
2460 nigel 73 Version 4.5 01-Dec-03
2461     ---------------------
2462    
2463     1. There has been some re-arrangement of the code for the match() function so
2464     that it can be compiled in a version that does not call itself recursively.
2465     Instead, it keeps those local variables that need separate instances for
2466     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2467     needs to "recurse". Keeping track of where control must go is done by means
2468     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2469     hide most of the details from the main code, and operates only if
2470     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2471     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2472     operating.
2473    
2474     To make it easier for callers to provide specially tailored get/free
2475     functions for this usage, two new functions, pcre_stack_malloc, and
2476     pcre_stack_free, are used. They are always called in strict stacking order,
2477     and the size of block requested is always the same.
2478    
2479     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2480     PCRE has been compiled to use the stack or the heap for recursion. The
2481     -C option of pcretest uses this to show which version is compiled.
2482    
2483     A new data escape \S, is added to pcretest; it causes the amounts of store
2484     obtained and freed by both kinds of malloc/free at match time to be added
2485     to the output.
2486    
2487     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2488     what's available on my current Linux desktop machine.
2489    
2490     3. When matching a UTF-8 string, the test for a valid string at the start has
2491     been extended. If start_offset is not zero, PCRE now checks that it points
2492     to a byte that is the start of a UTF-8 character. If not, it returns
2493     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2494     this is necessary because there may be backward assertions in the pattern.
2495     When matching the same subject several times, it may save resources to use
2496     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2497    
2498     4. The code for checking the validity of UTF-8 strings has been tightened so
2499     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2500     containing "overlong sequences".
2501    
2502     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2503     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2504     should have been "&", but it just so happened that all the cases this let
2505     through by mistake were picked up later in the function.
2506    
2507     6. I had used a variable called "isblank" - this is a C99 function, causing
2508     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2509    
2510     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2511     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2512     so the version is shown; (c) stop "make test" echoing "./RunTest".
2513    
2514     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2515    
2516     9. The prototype for memmove() for systems that don't have it was using
2517     size_t, but the inclusion of the header that defines size_t was later. I've
2518     moved the #includes for the C headers earlier to avoid this.
2519    
2520     10. Added some adjustments to the code to make it easier to compiler on certain
2521     special systems:
2522    
2523     (a) Some "const" qualifiers were missing.
2524     (b) Added the macro EXPORT before all exported functions; by default this
2525     is defined to be empty.
2526     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2527     that it reads its output file name as an argument instead of writing
2528     to the standard output and assuming this can be redirected.
2529    
2530     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2531     class containing characters with values greater than 255, PCRE compilation
2532     went into a loop.
2533    
2534     12. A recursive reference to a subpattern that was within another subpattern
2535     that had a minimum quantifier of zero caused PCRE to crash. For example,
2536     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2537     recursion. If the recursively-called subpattern itself had a zero repeat,
2538     that was OK.
2539    
2540     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2541     buffer into which it was copied (for escape processing) was still set at
2542     1024, so long lines caused crashes.
2543    
2544     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2545     "internal error: code overflow...". This applied to any character class
2546     that was followed by a possessive quantifier.
2547    
2548     15. Modified the Makefile to add libpcre.la as a prerequisite for
2549     libpcreposix.la because I was told this is needed for a parallel build to
2550     work.
2551    
2552     16. If a pattern that contained .* following optional items at the start was
2553     studied, the wrong optimizing data was generated, leading to matching
2554     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2555     matching string must start with a or b or c. The correct conclusion for
2556     this pattern is that a match can start with any character.
2557    
2558    
2559 nigel 71 Version 4.4 13-Aug-03
2560     ---------------------
2561    
2562     1. In UTF-8 mode, a character class containing characters with values between
2563     127 and 255 was not handled correctly if the compiled pattern was studied.
2564     In fixing this, I have also improved the studying algorithm for such
2565     classes (slightly).
2566    
2567     2. Three internal functions had redundant arguments passed to them. Removal
2568     might give a very teeny performance improvement.
2569    
2570     3. Documentation bug: the value of the capture_top field in a callout is *one
2571     more than* the number of the hightest numbered captured substring.
2572    
2573     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2574     in incorrectly linking with a previously installed version. They now link
2575     explicitly with libpcre.la.
2576    
2577     5. configure.in no longer needs to recognize Cygwin specially.
2578    
2579     6. A problem in pcre.in for Windows platforms is fixed.
2580    
2581     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2582     pcretest, it used to include the size of the study block as part of its
2583     output. Unfortunately, the structure contains a field that has a different
2584     size on different hardware architectures. This meant that the tests that
2585     showed this size failed. As the block is currently always of a fixed size,
2586     this information isn't actually particularly useful in pcretest output, so
2587     I have just removed it.
2588    
2589     8. Three pre-processor statements accidentally did not start in column 1.
2590     Sadly, there are *still* compilers around that complain, even though
2591     standard C has not required this for well over a decade. Sigh.
2592    
2593     9. In pcretest, the code for checking callouts passed small integers in the
2594     callout_data field, which is a void * field. However, some picky compilers
2595     complained about the casts involved for this on 64-bit systems. Now
2596     pcretest passes the address of the small integer instead, which should get
2597     rid of the warnings.
2598    
2599     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2600     both compile and run time, and gives an error if an invalid UTF-8 sequence
2601     is found. There is a option for disabling this check in cases where the
2602     string is known to be correct and/or the maximum performance is wanted.
2603    
2604     11. In response to a bug report, I changed one line in Makefile.in from
2605    
2606     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2607     to
2608     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2609    
2610     to look similar to other lines, but I have no way of telling whether this
2611     is the right thing to do, as I do not use Windows. No doubt I'll get told
2612     if it's wrong...
2613    
2614    
2615 nigel 69 Version 4.3 21-May-03
2616     ---------------------
2617    
2618     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2619     Makefile.
2620    
2621     2. Some refactoring to improve the quality of the code:
2622    
2623     (i) The utf8_table... variables are now declared "const".
2624    
2625     (ii) The code for \cx, which used the "case flipping" table to upper case
2626     lower case letters, now just substracts 32. This is ASCII-specific,
2627     but the whole concept of \cx is ASCII-specific, so it seems
2628     reasonable.
2629    
2630     (iii) PCRE was using its character types table to recognize decimal and
2631     hexadecimal digits in the pattern. This is silly, because it handles
2632     only 0-9, a-f, and A-F, but the character types table is locale-
2633     specific, which means strange things might happen. A private
2634     table is now used for this - though it costs 256 bytes, a table is
2635     much faster than multiple explicit tests. Of course, the standard
2636     character types table is still used for matching digits in subject
2637     strings against \d.
2638    
2639     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2640     ending in _t are). So I've renamed it as ESC_tee.
2641    
2642     3. The first argument for regexec() in the POSIX wrapper should have been
2643     defined as "const".
2644    
2645     4. Changed pcretest to use malloc() for its buffers so that they can be
2646     Electric Fenced for debugging.
2647    
2648     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2649     to read one or more bytes before the start of the subject string. Often this
2650     had no effect on PCRE's behaviour, but in some circumstances it could
2651     provoke a segmentation fault.
2652    
2653     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2654     to try to read one or more bytes before the start of the subject string.
2655    
2656     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2657     UTF-8 support could misbehave in various ways if the subject string
2658     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2659     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2660     back over UTF-8 characters.)
2661    
2662    
2663 nigel 67 Version 4.2 14-Apr-03
2664     ---------------------
2665    
2666     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2667    
2668     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2669     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2670     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2671     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2672     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2673     and BUILD_EXEEXT
2674     Note: automatic setting of the BUILD variables is not yet working
2675     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2676     compile-time but not at link-time
2677     [LINK]: use for linking executables only
2678     make different versions for Windows and non-Windows
2679     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2680     libraries
2681     [LINK_FOR_BUILD]: new variable
2682     [OBJEXT]: use throughout
2683     [EXEEXT]: use throughout
2684     <winshared>: new target
2685     <wininstall>: new target
2686     <dftables.o>: use native compiler
2687     <dftables>: use native linker
2688     <install>: handle Windows platform correctly
2689     <clean>: ditto
2690     <check>: ditto
2691     copy DLL to top builddir before testing
2692    
2693     As part of these changes, -no-undefined was removed again. This was reported
2694     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2695     in any case.
2696    
2697     3. Some tidies to get rid of compiler warnings:
2698    
2699     . In the match_data structure, match_limit was an unsigned long int, whereas
2700     match_call_count was an int. I've made them both unsigned long ints.
2701    
2702     . In pcretest the fact that a const uschar * doesn't automatically cast to
2703     a void * provoked a warning.
2704    
2705     . Turning on some more compiler warnings threw up some "shadow" variables
2706     and a few more missing casts.
2707    
2708     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2709     option, a class that contained a single character with a value between 128
2710     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2711    
2712     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2713     option, a class that contained several characters, but with at least one
2714     whose value was between 128 and 255 caused PCRE to crash.
2715    
2716    
2717 nigel 65 Version 4.1 12-Mar-03
2718     ---------------------
2719 nigel 63
2720 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2721     needed, and a string in dftables.c that was longer than standard compilers are
2722     required to support.
2723    
2724     2. Compiling with Sun's compiler found a few more places where the code could
2725     be tidied up in order to avoid warnings.
2726    
2727     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2728     first of these names is deprecated in the latest Autoconf in favour of the name
2729     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2730     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2731     analogy I have changed it to CFLAGS_FOR_BUILD.
2732    
2733     4. Added -no-undefined to the linking command in the Makefile, because this is
2734     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2735     linking step for the pcreposix library.
2736    
2737     5. PCRE was failing to diagnose the case of two named groups with the same
2738     name.
2739    
2740     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2741     literal character that is needed in the subject for a match, and scans along to
2742     ensure that it is present before embarking on the full matching process. This
2743     saves time in cases of nested unlimited repeats that are never going to match.
2744     Problem: the scan can take a lot of time if the subject is very long (e.g.
2745     megabytes), thus penalizing straightforward matches. It is now done only if the
2746     amount of subject to be scanned is less than 1000 bytes.
2747    
2748     7. A lesser problem with the same optimization is that it was recording the
2749     first character of an anchored pattern as "needed", thus provoking a search
2750     right along the subject, even when the first match of the pattern was going to
2751     fail. The "needed" character is now not set for anchored patterns, unless it
2752     follows something in the pattern that is of non-fixed length. Thus, it still
2753     fulfils its original purpose of finding quick non-matches in cases of nested
2754     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2755    
2756    
2757     Version 4.0 17-Feb-03
2758     ---------------------
2759    
2760 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2761     extended to the end of string, PCRE compiled incorrect data. This could lead to
2762     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2763    
2764     2. Moved to autoconf 2.53 and libtool 1.4.2.
2765    
2766     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2767     the special perltest8 script is no longer needed - all the tests can be run
2768     from a single perltest script.
2769    
2770     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2771     by \s. It has now been removed in PCRE. This means it isn't recognized as
2772     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2773     class [:space:] *does* include VT, thereby creating a mess.
2774    
2775     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2776     space and tab.
2777    
2778     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2779     its new features into the main test script, reducing the number of scripts.
2780    
2781     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2782     were backward compatible, and made the (?i) apply to the whole pattern, as if
2783     /i were given. Now it behaves more logically, and applies the option setting
2784     only to what follows. PCRE has been changed to follow suit. However, if it
2785     finds options settings right at the start of the pattern, it extracts them into
2786     the global options, as before. Thus, they show up in the info data.
2787    
2788     8. Added support for the \Q...\E escape sequence. Characters in between are
2789     treated as literals. This is slightly different from Perl in that $ and @ are
2790     also handled as literals inside the quotes. In Perl, they will cause variable
2791     interpolation. Note the following examples:
2792    
2793     Pattern PCRE matches Perl matches
2794    
2795     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2796     \Qabc\$xyz\E abc\$xyz abc\$xyz
2797     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2798    
2799     For compatibility with Perl, \Q...\E sequences are recognized inside character
2800     classes as well as outside them.
2801    
2802     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2803     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2804     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2805     signed/unsigned warnings.
2806    
2807     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2808     option for pcretest, so I've replaced it by a simple function that does just
2809     that job.
2810    
2811     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2812     "pcregrep -".
2813    
2814     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2815     Java package. This provides some syntactic sugar for simple cases of what my
2816     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2817     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2818     item, you can use this simplified notation. Note that only makes sense with
2819     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2820     greediness, whatever the setting of the PCRE_UNGREEDY option.
2821    
2822     13. A change of greediness default within a pattern was not taking effect at
2823     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2824     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2825     was abstracted outside.
2826    
2827     14. PCRE now supports the \G assertion. It is true when the current matching
2828     position is at the start point of the match. This differs from \A when the
2829     starting offset is non-zero. Used with the /g option of pcretest (or similar
2830     code), it works in the same way as it does for Perl's /g option. If all
2831     alternatives of a regex begin with \G, the expression is anchored to the start
2832     match position, and the "anchored" flag is set in the compiled expression.
2833    
2834     15. Some bugs concerning the handling of certain option changes within patterns
2835     have been fixed. These applied to options other than (?ims). For example,
2836     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2837     been the other way round. Some of this was related to change 7 above.
2838    
2839     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2840     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2841     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2842     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2843    
2844     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2845     mode. Unlike ".", it always matches newline, whatever the setting of
2846     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2847     assertions. Perl allows it, but it doesn't (in general) work because it can't
2848     calculate the length of the lookbehind. At least, that's the case for Perl
2849     5.8.0 - I've been told they are going to document that it doesn't work in
2850     future.
2851    
2852     18. Added an error diagnosis for escapes that PCRE does not support: these are
2853     \L, \l, \N, \P, \p, \U, \u, and \X.
2854    
2855     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2856     reading past the end of the pattern in cases such as /[abcd/.
2857    
2858     20. PCRE was getting more memory than necessary for patterns with classes that
2859     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2860    
2861     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2862     compiling PCRE for use with Virtual Pascal.
2863    
2864     22. Small fix to the Makefile to make it work properly if the build is done
2865     outside the source tree.
2866    
2867     23. Added a new extension: a condition to go with recursion. If a conditional
2868     subpattern starts with (?(R) the "true" branch is used if recursion has
2869     happened, whereas the "false" branch is used only at the top level.
2870    
2871     24. When there was a very long string of literal characters (over 255 bytes
2872     without UTF support, over 250 bytes with UTF support), the computation of how
2873     much memory was required could be incorrect, leading to segfaults or other
2874     strange effects.
2875    
2876     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2877     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2878     there was a subsequent back reference to those brackets. This meant that, for
2879     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2880     possible to check for precisely this case. All we can do is abandon the
2881     optimization if .* occurs inside capturing brackets when there are any back
2882     references whatsoever. (See below for a better fix that came later.)
2883    
2884     26. The handling of the optimization for finding the first character of a
2885     non-anchored pattern, and for finding a character that is required later in the
2886     match were failing in some cases. This didn't break the matching; it just
2887     failed to optimize when it could. The way this is done has been re-implemented.
2888    
2889     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2890    
2891     28. Added a new feature that provides some of the functionality that Perl
2892     provides with (?{...}). The facility is termed a "callout". The way it is done
2893     in PCRE is for the caller to provide an optional function, by setting
2894     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2895     global variable. By default it is unset, which disables all calling out. To get
2896     the function called, the regex must include (?C) at appropriate points. This
2897     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2898     This provides a means of identifying different callout points. When PCRE
2899     reaches such a point in the regex, if pcre_callout has been set, the external
2900     function is called. It is provided with data in a structure called
2901     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2902     matching continues; if it returns a non-zero value, the match at the current
2903     point fails. However, backtracking will occur if possible. [This was changed
2904     later and other features added - see item 49 below.]
2905    
2906     29. pcretest is upgraded to test the callout functionality. It provides a
2907     callout function that displays information. By default, it shows the start of
2908     the match and the current position in the text. There are some new data escapes
2909     to vary what happens:
2910    
2911     \C+ in addition, show current contents of captured substrings
2912     \C- do not supply a callout function
2913     \C!n return 1 when callout number n is reached
2914     \C!n!m return 1 when callout number n is reached for the mth time
2915    
2916     30. If pcregrep was called with the -l option and just a single file name, it
2917     output "<stdin>" if a match was found, instead of the file name.
2918    
2919     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2920     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2921     pcre_exec(). This saves a malloc/free per call. The default value of
2922     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2923     when configuring.
2924    
2925     32. The default maximum size of a compiled pattern is 64K. There have been a
2926     few cases of people hitting this limit. The code now uses macros to handle the
2927     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2928     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2929     configuring. Tests 2 and 5 work only with 2-byte links because they output
2930     debugging information about compiled patterns.
2931    
2932     33. Internal code re-arrangements:
2933    
2934     (a) Moved the debugging function for printing out a compiled regex into
2935     its own source file (printint.c) and used #include to pull it into
2936     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2937     separate copies.
2938    
2939     (b) Defined the list of op-code names for debugging as a macro in
2940     internal.h so that it is next to the definition of the opcodes.
2941    
2942     (c) Defined a table of op-code lengths for simpler skipping along compiled
2943     code. This is again a macro in internal.h so that it is next to the
2944     definition of the opcodes.
2945    
2946     34. Added support for recursive calls to individual subpatterns, along the
2947     lines of Robin Houston's patch (but implemented somewhat differently).
2948    
2949     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2950     allow it to read and process whole directories in Win32. This code was
2951     contributed by Lionel Fourquaux; it has not been tested by me.
2952    
2953     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2954     used to name a group. Names consist of alphanumerics and underscores, and must
2955     be unique. Back references use the syntax (?P=name) and recursive calls use
2956     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2957     numbers. The function pcre_fullinfo() can be used after compilation to extract
2958     a name/number map. There are three relevant calls:
2959    
2960     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2961     PCRE_INFO_NAMECOUNT yields the number of entries
2962     PCRE_INFO_NAMETABLE yields a pointer to the map.
2963    
2964     The map is a vector of fixed-size entries. The size of each entry depends on
2965     the length of the longest name used. The first two bytes of each entry are the
2966     group number, most significant byte first. There follows the corresponding
2967     name, zero terminated. The names are in alphabetical order.
2968    
2969     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2970     case instead of 255. Making it the same both with and without UTF-8 support
2971     means that the same test output works with both.
2972    
2973     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2974     calling malloc() with a zero argument.
2975    
2976     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2977     optimization. I've improved things by keeping a bitmap of backreferences with
2978     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2979     fact referenced, the optimization can be applied. It is unlikely that a
2980     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2981     the match to follow \n) will appear inside brackets with a number greater than
2982     31, but if it does, any back reference > 31 suppresses the optimization.
2983    
2984     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2985     of disabling numbered capturing parentheses. Any opening parenthesis that is
2986     not followed by ? behaves as if it were followed by ?: but named parentheses
2987     can still be used for capturing (and they will acquire numbers in the usual
2988     way).
2989    
2990     41. Redesigned the return codes from the match() function into yes/no/error so
2991     that errors can be passed back from deep inside the nested calls. A malloc
2992     failure while inside a recursive subpattern call now causes the
2993     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2994    
2995     42. It is now possible to set a limit on the number of times the match()
2996     function is called in a call to pcre_exec(). This facility makes it possible to
2997     limit the amount of recursion and backtracking, though not in a directly
2998     obvious way, because the match() function is used in a number of different
2999     circumstances. The count starts from zero for each position in the subject
3000     string (for non-anchored patterns). The default limit is, for compatibility, a
3001     large number, namely 10 000 000. You can change this in two ways:
3002    
3003     (a) When configuring PCRE before making, you can use --with-match-limit=n
3004     to set a default value for the compiled library.
3005    
3006     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3007     a different value is set. See 45 below.
3008    
3009     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3010    
3011     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3012     of things that can be changed at compile time. The first argument specifies
3013     what is wanted and the second points to where the information is to be placed.
3014     The current list of available information is:
3015    
3016     PCRE_CONFIG_UTF8
3017    
3018     The output is an integer that is set to one if UTF-8 support is available;
3019     otherwise it is set to zero.
3020    
3021     PCRE_CONFIG_NEWLINE
3022    
3023     The output is an integer that it set to the value of the code that is used for
3024     newline. It is either LF (10) or CR (13).
3025    
3026     PCRE_CONFIG_LINK_SIZE
3027    
3028     The output is an integer that contains the number of bytes used for internal
3029     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3030    
3031     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3032    
3033     The output is an integer that contains the threshold above which the POSIX
3034     interface uses malloc() for output vectors. See item 31 above.
3035    
3036     PCRE_CONFIG_MATCH_LIMIT
3037    
3038     The output is an unsigned integer that contains the default limit of the number
3039     of match() calls in a pcre_exec() execution. See 42 above.
3040    
3041     44. pcretest has been upgraded by the addition of the -C option. This causes it
3042     to extract all the available output from the new pcre_config() function, and to
3043     output it. The program then exits immediately.
3044    
3045     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3046     order to support additional features. One way would have been to define
3047     pcre_exec2() (for example) with extra arguments, but this would not have been
3048     extensible, and would also have required all calls to the original function to
3049     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3050     is used for passing in "extra" data from pcre_study().
3051    
3052     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3053     contains the following fields:
3054    
3055     flags a bitmap indicating which of the following fields are set
3056     study_data opaque data from pcre_study()
3057     match_limit a way of specifying a limit on match() calls for a specific
3058     call to pcre_exec()
3059     callout_data data for callouts (see 49 below)
3060    
3061     The flag bits are also defined in pcre.h, and are
3062    
3063     PCRE_EXTRA_STUDY_DATA
3064     PCRE_EXTRA_MATCH_LIMIT
3065     PCRE_EXTRA_CALLOUT_DATA
3066    
3067     The pcre_study() function now returns one of these new pcre_extra blocks, with
3068     the actual study data pointed to by the study_data field, and the
3069     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3070     before. That is, this change is entirely upwards-compatible and requires no
3071     change to existing code.
3072    
3073     If you want to pass in additional data to pcre_exec(), you can either place it
3074     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3075     block.
3076    
3077     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3078     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3079     times with different match limits, until it finds the minimum value needed for
3080     pcre_exec() to complete. The value is then output. This can be instructive; for
3081     most simple matches the number is quite small, but for pathological cases it
3082     gets very large very quickly.
3083    
3084     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3085     returns the size of the data block pointed to by the study_data field in a
3086     pcre_extra block, that is, the value that was passed as the argument to
3087     pcre_malloc() when PCRE was getting memory in which to place the information
3088     created by pcre_study(). The fourth argument should point to a size_t variable.
3089     pcretest has been extended so that this information is shown after a successful
3090     pcre_study() call when information about the compiled regex is being displayed.
3091    
3092     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3093     because what follows is always an absolute path. (Later: it turns out that this
3094     is more than cosmetic for MinGW, because it doesn't like empty path
3095     components.)
3096    
3097     49. Some changes have been made to the callout feature (see 28 above):
3098    
3099     (i) A callout function now has three choices for what it returns:
3100    
3101     0 => success, carry on matching
3102     > 0 => failure at this point, but backtrack if possible
3103     < 0 => serious error, return this value from pcre_exec()
3104    
3105     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3106     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3107     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3108     use by callout functions. It will never be used by PCRE itself.
3109    
3110     (ii) The pcre_extra structure (see 45 above) has a void * field called
3111     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3112     pcre_callout_block structure has a field of the same name. The contents of
3113     the field passed in the pcre_extra structure are passed to the callout
3114     function in the corresponding field in the callout block. This makes it
3115     easier to use the same callout-containing regex from multiple threads. For
3116     testing, the pcretest program has a new data escape
3117    
3118     \C*n pass the number n (may be negative) as callout_data
3119    
3120     If the callout function in pcretest receives a non-zero value as
3121     callout_data, it returns that value.
3122    
3123     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3124     there were some redundant $(CFLAGS) in commands that are now specified as
3125     $(LINK), which already includes $(CFLAGS).
3126    
3127     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3128     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3129     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3130     one-byte characters throughout. Note that case-insensitive matching applies
3131     only to characters whose values are less than 256. PCRE doesn't support the
3132     notion of cases for higher-valued characters.
3133    
3134     (i) A character class whose characters are all within 0-255 is handled as
3135     a bit map, and the map is inverted for negative classes. Previously, a
3136     character > 255 always failed to match such a class; however it should
3137     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3138    
3139     (ii) A negated character class with a single character < 255 is coded as
3140     "not this character" (OP_NOT). This wasn't working properly when the test
3141     character was multibyte, either singly or repeated.
3142    
3143     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3144     mode, for example: \x{100}{2,3}.
3145    
3146     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3147     singly or repeated) now correctly test multibyte characters. However,
3148     PCRE doesn't recognize any characters with values greater than 255 as
3149     digits, spaces, or word characters. Such characters always match \D, \S,
3150     and \W, and never match \d, \s, or \w.
3151    
3152     (v) Classes may now contain characters and character ranges with values
3153     greater than 255. For example: [ab\x{100}-\x{400}].
3154    
3155     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3156     PCRE in UTF-8 mode.
3157    
3158     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3159     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3160     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3161     value.)
3162    
3163     53. The single man page has become too large. I have therefore split it up into
3164     a number of separate man pages. These also give rise to individual HTML pages;
3165     these are now put in a separate directory, and there is an index.html page that
3166     lists them all. Some hyperlinking between the pages has been installed.
3167    
3168     54. Added convenience functions for handling named capturing parentheses.
3169    
3170     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3171     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3172     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3173     are faulted.
3174    
3175     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3176     calling configure. These values are used when compiling the dftables.c program
3177     which is run to generate the source of the default character tables. They
3178     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3179     you will need to set these values.
3180    
3181     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3182    
3183    
3184     Version 3.9 02-Jan-02
3185 nigel 61 ---------------------
3186    
3187     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3188    
3189     2. If --disable-static was given, the building process failed when trying to
3190     build pcretest and pcregrep. (For some reason it was using libtool to compile
3191     them, which is not right, as they aren't part of the library.)
3192    
3193    
3194 nigel 59 Version 3.8 18-Dec-01
3195     ---------------------
3196    
3197     1. The experimental UTF-8 code was completely screwed up. It was packing the
3198     bytes in the wrong order. How dumb can you get?
3199    
3200    
3201 nigel 57 Version 3.7 29-Oct-01
3202     ---------------------
3203    
3204     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3205     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3206     this didn't happen under Solaris 8, where I normally test things.
3207    
3208 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3209     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3210     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3211     this fix an hour or so after the initial 3.7 release.)
3212 nigel 57
3213 nigel 59
3214 nigel 55 Version 3.6 23-Oct-01
3215     ---------------------
3216    
3217     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3218     offsets passed as NULL with zero offset count.
3219    
3220     2. The config.guess and config.sub files had not been updated when I moved to
3221     the latest autoconf.
3222    
3223    
3224 nigel 53 Version 3.5 15-Aug-01
3225     ---------------------
3226 nigel 5
3227 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3228     had been forgotten.
3229    
3230     2. By using declared but undefined structures, we can avoid using "void"
3231     definitions in pcre.h while keeping the internal definitions of the structures
3232     private.
3233    
3234     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3235     user point of view, this means that both static and shared libraries are built
3236     by default, but this can be individually controlled. More of the work of
3237     handling this static/shared cases is now inside libtool instead of PCRE's make
3238     file.
3239    
3240     4. The pcretest utility is now installed along with pcregrep because it is
3241     useful for users (to test regexs) and by doing this, it automatically gets
3242     relinked by libtool. The documentation has been turned into a man page, so
3243     there are now .1, .txt, and .html versions in /doc.
3244    
3245     5. Upgrades to pcregrep:
3246     (i) Added long-form option names like gnu grep.
3247     (ii) Added --help to list all options with an explanatory phrase.
3248     (iii) Added -r, --recursive to recurse into sub-directories.
3249     (iv) Added -f, --file to read patterns from a file.
3250    
3251     6. pcre_exec() was referring to its "code" argument before testing that
3252     argument for NULL (and giving an error if it was NULL).
3253    
3254     7. Upgraded Makefile.in to allow for compiling in a different directory from
3255     the source directory.
3256    
3257     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3258     options bits, the pointer it was passed was to an int instead of to an unsigned
3259     long int. This mattered only on 64-bit systems.
3260    
3261     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3262     generated) instead of pcre.in, which it its source. Also made the same change
3263     in several of the .c files.
3264    
3265     10. A new release of gcc defines printf() as a macro, which broke pcretest
3266     because it had an ifdef in the middle of a string argument for printf(). Fixed
3267     by using separate calls to printf().
3268    
3269     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3270     script, to force use of CR or LF instead of \n in the source. On non-Unix
3271     systems, the value can be set in config.h.
3272    
3273     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3274     absolute limit. Changed the text of the error message to make this clear, and
3275     likewise updated the man page.
3276    
3277     13. The limit of 99 on the number of capturing subpatterns has been removed.
3278     The new limit is 65535, which I hope will not be a "real" limit.
3279    
3280    
3281 nigel 51 Version 3.4 22-Aug-00
3282     ---------------------
3283    
3284     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3285    
3286     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3287    
3288    
3289 nigel 49 Version 3.3 01-Aug-00
3290     ---------------------
3291    
3292     1. If an octal character was given, but the value was greater than \377, it
3293     was not getting masked to the least significant bits, as documented. This could
3294     lead to crashes in some systems.
3295    
3296     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3297     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3298    
3299     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3300     These just pass their arguments on to (pcre_free)(), but they are provided
3301     because some uses of PCRE bind it to non-C systems that can call its functions,
3302     but cannot call free() or pcre_free() directly.
3303    
3304     4. Add "make test" as a synonym for "make check". Corrected some comments in
3305     the Makefile.
3306    
3307     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3308     Makefile.
3309    
3310     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3311     command called pgrep for grepping around the active processes.
3312    
3313     7. Added the beginnings of support for UTF-8 character strings.
3314    
3315     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3316     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3317     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3318     out for the ar command.)
3319    
3320    
3321 nigel 47 Version 3.2 12-May-00
3322     ---------------------
3323    
3324     This is purely a bug fixing release.
3325    
3326     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3327     of ZA. This was just one example of several cases that could provoke this bug,
3328     which was introduced by change 9 of version 2.00. The code for breaking
3329     infinite loops after an iteration that matches an empty string was't working
3330     correctly.
3331    
3332     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3333     when matched against abbab (for example). After matching an empty string, it
3334     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3335     caused it to match further down the string than it should.
3336    
3337     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3338     was there because it doesn't seem to be needed, and it causes trouble on some
3339     systems, as it is not a Standard C header. It has been removed.
3340    
3341     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3342     were reported on the Macintosh. The changes were from
3343    
3344     while ((c = *(++ptr)) != 0 && c != '\n');
3345     to
3346     while ((c = *(++ptr)) != 0 && c != '\n') ;
3347    
3348     Totally extraordinary, but if that's what it takes...
3349    
3350     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3351     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3352     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3353     assumes the way PCRE uses memmove() (always moving upwards).
3354    
3355     6. PCRE is being used in one environment where strchr() is not available. There
3356     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3357     faster code anyway.
3358    
3359    
3360 nigel 45 Version 3.1 09-Feb-00
3361     ---------------------
3362    
3363     The only change in this release is the fixing of some bugs in Makefile.in for
3364     the "install" target:
3365    
3366     (1) It was failing to install pcreposix.h.
3367    
3368     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3369    
3370    
3371 nigel 43 Version 3.0 01-Feb-00
3372     ---------------------
3373 nigel 41
3374     1. Add support for the /+ modifier to perltest (to output $` like it does in
3375     pcretest).
3376    
3377     2. Add support for the /g modifier to perltest.
3378    
3379     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3380     matches null strings.
3381    
3382     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3383     pattern. Perl treats empty patterns specially - it reuses the most recent
3384     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3385     effect.
3386    
3387     5. The POSIX interface was broken in that it was just handing over the POSIX
3388     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3389     required a bigger vector, with some working space on the end. This means that
3390     the POSIX wrapper now has to get and free some memory, and copy the results.
3391    
3392 nigel 43 6. Added some simple autoconf support, placing the test data and the
3393     documentation in separate directories, re-organizing some of the
3394     information files, and making it build pcre-config (a GNU standard). Also added
3395     libtool support for building PCRE as a shared library, which is now the
3396     default.
3397 nigel 41
3398 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3399     09 are not valid octal constants. Single digits will be used for minor values
3400     less than 10.
3401    
3402     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3403     existing programs that set these in the POSIX interface can use PCRE without
3404     modification.
3405    
3406     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3407     return all that pcre_info() returns, plus additional data. The pcre_info()
3408     function is retained for compatibility, but is considered to be obsolete.
3409    
3410     10. Added experimental recursion feature (?R) to handle one common case that
3411     Perl 5.6 will be able to do with (?p{...}).
3412    
3413     11. Added support for POSIX character classes like [:alpha:], which Perl is
3414     adopting.
3415    
3416    
3417 nigel 39 Version 2.08 31-Aug-99
3418     ----------------------
3419    
3420     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3421     trying to match at the startoffset position, but instead was moving forward to
3422     the next newline as if a previous match had failed.
3423    
3424     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3425     and could get into a loop if a null string was matched other than at the start
3426     of the subject.
3427    
3428     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3429     be distinguished at compile time, and for completeness also added PCRE_DATE.
3430    
3431     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3432     in GnuWin32 environments.
3433    
3434    
3435 nigel 37 Version 2.07 29-Jul-99
3436     ----------------------
3437    
3438     1. The documentation is now supplied in plain text form and HTML as well as in
3439     the form of man page sources.
3440    
3441     2. C++ compilers don't like assigning (void *) values to other pointer types.
3442     In particular this affects malloc(). Although there is no problem in Standard
3443     C, I've put in casts to keep C++ compilers happy.
3444    
3445     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3446     should be (const char *).
3447    
3448     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3449     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3450     However, I haven't made this a standard facility. The documentation doesn't
3451     mention it, and the Makefile doesn't support it.
3452    
3453     5. The Makefile now contains an "install" target, with editable destinations at
3454     the top of the file. The pcretest program is not installed.
3455    
3456     6. pgrep -V now gives the PCRE version number and date.
3457    
3458     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3459     causing the entire string to be ignored, instead of just the last character.
3460    
3461     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3462     non-matching string, it can take a very, very long time, even for strings of
3463     quite modest length, because of the nested recursion. PCRE now does better in
3464     some of these cases. It does this by remembering the last required literal
3465     character in the pattern, and pre-searching the subject to ensure it is present
3466     before running the real match. In other words, it applies a heuristic to detect
3467     some types of certain failure quickly, and in the above example, if presented
3468     with a string that has no trailing " it gives "no match" very quickly.
3469    
3470     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3471     other alternatives are tried instead.
3472    
3473    
3474 nigel 35 Version 2.06 09-Jun-99
3475     ----------------------
3476    
3477     1. Change pcretest's output for amount of store used to show just the code
3478     space, because the remainder (the data block) varies in size between 32-bit and
3479     64-bit systems.
3480    
3481     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3482     start matching at. This allows lookbehinds to work when searching for multiple
3483     occurrences in a string.
3484    
3485     3. Added additional options to pcretest for testing multiple occurrences:
3486    
3487     /+ outputs the rest of the string that follows a match
3488     /g loops for multiple occurrences, using the new startoffset argument
3489     /G loops for multiple occurrences by passing an incremented pointer
3490    
3491     4. PCRE wasn't doing the "first character" optimization for patterns starting
3492     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3493     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3494     the letter 'x'. On long subject strings, this gives a significant speed-up.
3495    
3496    
3497 nigel 33 Version 2.05 21-Apr-99
3498     ----------------------
3499    
3500     1. Changed the type of magic_number from int to long int so that it works
3501     properly on 16-bit systems.
3502    
3503     2. Fixed a bug which caused patterns starting with .* not to work correctly
3504     when the subject string contained newline characters. PCRE was assuming
3505     anchoring for such patterns in all cases, which is not correct because .* will
3506     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3507     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3508     must be retried after every newline in the subject.
3509    
3510    
3511 nigel 31 Version 2.04 18-Feb-99
3512     ----------------------
3513    
3514     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3515     computation of the store needed to hold the pattern was incorrect (too large).
3516     If such patterns were nested a few deep, this could multiply and become a real
3517     problem.
3518    
3519     2. Added /M option to pcretest to show the memory requirement of a specific
3520     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3521    
3522     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3523     compiled in such a way that the backtracking after subsequent failure was
3524     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3525     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3526    
3527    
3528 nigel 29 Version 2.03 02-Feb-99
3529     ----------------------
3530    
3531     1. Fixed typo and small mistake in man page.
3532    
3533 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3534     LICENCE file containing the conditions.
3535 nigel 29
3536     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3537     Perl, that is the internal \ allows the delimiter to be included in the
3538     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3539     the final delimiter, add \ to the end of the pattern (to test the error).
3540    
3541     4. Added the convenience functions for extracting substrings after a successful
3542     match. Updated pcretest to make it able to test these functions.
3543    
3544    
3545 nigel 27 Version 2.02 14-Jan-99
3546     ----------------------
3547    
3548     1. Initialized the working variables associated with each extraction so that
3549     their saving and restoring doesn't refer to uninitialized store.
3550    
3551     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3552     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3553     fix the problem.
3554    
3555     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3556     calls, and wasn't printing the correct value for compiling calls. Increased the
3557     default value of LOOPREPEAT, and the number of significant figures in the
3558     times.
3559    
3560     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3561    
3562     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3563     a building problem on Windows NT with a FAT file system.
3564    
3565    
3566 nigel 25 Version 2.01 21-Oct-98
3567     ----------------------
3568    
3569     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3570     to character tables built by pcre_maketables() in the current locale. If NULL
3571     is passed, the default tables are used.
3572    
3573    
3574 nigel 23 Version 2.00 24-Sep-98
3575 nigel 21 ----------------------
3576    
3577 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3578     it any more.
3579    
3580     2. Allow quantification of (?>) groups, and make it work correctly.
3581    
3582     3. The first character computation wasn't working for (?>) groups.
3583    
3584     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3585     end of the subject) and add 5.005's \z, which really does match only at the
3586     very end of the subject.
3587    
3588     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3589    
3590     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3591     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3592     localized options. All options to pcre_study() were also removed.
3593    
3594     7. Add other new features from 5.005:
3595    
3596     $(?<= positive lookbehind
3597     $(?<! negative lookbehind
3598     (?imsx-imsx) added the unsetting capability
3599     such a setting is global if at outer level; local otherwise
3600     (?imsx-imsx:) non-capturing groups with option setting
3601     (?(cond)re|re) conditional pattern matching
3602    
3603     A backreference to itself in a repeated group matches the previous
3604     captured string.
3605    
3606     8. General tidying up of studying (both automatic and via "study")
3607     consequential on the addition of new assertions.
3608    
3609     9. As in 5.005, unlimited repeated groups that could match an empty substring
3610     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3611     runtime if any iteration does actually match an empty substring.
3612    
3613     10. Include the RunTest script in the distribution.
3614    
3615     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3616     discrepancies, some of which were old and were also with respect to 5.004. They
3617     have now been fixed.
3618    
3619    
3620     Version 1.09 28-Apr-98
3621     ----------------------
3622    
3623 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3624     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3625     program crashes, or just wrong answers. This did not apply to negated classes
3626     containing more than one character, or to minima other than one.
3627    
3628    
3629 nigel 19 Version 1.08 27-Mar-98
3630     ----------------------
3631    
3632     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3633    
3634     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3635     latter must appear before anything that relies on it in the pattern.
3636    
3637    
3638 nigel 17 Version 1.07 16-Feb-98
3639     ----------------------
3640    
3641     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3642     repeat of a potentially empty string).
3643    
3644    
3645 nigel 15 Version 1.06 23-Jan-98
3646     ----------------------
3647    
3648     1. Added Markus Oberhumer's little patches for C++.
3649    
3650     2. Literal strings longer than 255 characters were broken.
3651    
3652    
3653 nigel 13 Version 1.05 23-Dec-97
3654     ----------------------
3655    
3656     1. Negated character classes containing more than one character were failing if
3657     PCRE_CASELESS was set at run time.
3658    
3659    
3660 nigel 11 Version 1.04 19-Dec-97
3661     ----------------------
3662    
3663     1. Corrected the man page, where some "const" qualifiers had been omitted.
3664    
3665     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3666     input syntax.
3667    
3668     3. Fixed memory leak which occurred when a regex with back references was
3669     matched with an offsets vector that wasn't big enough. The temporary memory
3670     that is used in this case wasn't being freed if the match failed.
3671    
3672     4. Tidied pcretest to ensure it frees memory that it gets.
3673    
3674     5. Temporary memory was being obtained in the case where the passed offsets
3675     vector was exactly big enough.
3676    
3677     6. Corrected definition of offsetof() from change 5 below.
3678    
3679     7. I had screwed up change 6 below and broken the rules for the use of
3680     setjmp(). Now fixed.
3681    
3682    
3683 nigel 9 Version 1.03 18-Dec-97
3684     ----------------------
3685    
3686     1. A erroneous regex with a missing opening parenthesis was correctly
3687     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3688     on some systems.
3689    
3690     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3691     it was reported that one broken compiler failed on the former because "code" is
3692     also an independent variable.
3693    
3694     3. The erroneous regex a[]b caused an array overrun reference.
3695    
3696     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3697     fail on data ending with that character. (It was going on too far, and checking
3698     the next character, typically a binary zero.) This was specific to the
3699     optimized code for single-character negative classes.
3700    
3701     5. Added a contributed patch from the TIN world which does the following:
3702    
3703     + Add an undef for memmove, in case the the system defines a macro for it.
3704    
3705     + Add a definition of offsetof(), in case there isn't one. (I don't know
3706     the reason behind this - offsetof() is part of the ANSI standard - but
3707     it does no harm).
3708    
3709     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3710     most of the places where whitespace preceded '#'. I have given up and
3711     allowed the remaining 2 cases to be at the margin.
3712    
3713     + Rename some variables in pcre to eliminate shadowing. This seems very
3714     pedantic, but does no harm, of course.
3715    
3716     6. Moved the call to setjmp() into its own function, to get rid of warnings
3717     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3718    
3719     7. Constructs such as \d{8,} were compiling into the equivalent of
3720 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3721 nigel 9 outcome, but in this particular case used more store than had been allocated,
3722     which caused the bug to be discovered because it threw up an internal error.
3723    
3724     8. The debugging code in both pcre and pcretest for outputting the compiled
3725     form of a regex was going wrong in the case of back references followed by
3726     curly-bracketed repeats.
3727    
3728    
3729 nigel 7 Version 1.02 12-Dec-97
3730     ----------------------
3731    
3732     1. Typos in pcre.3 and comments in the source fixed.
3733    
3734     2. Applied a contributed patch to get rid of places where it used to remove
3735     'const' from variables, and fixed some signed/unsigned and uninitialized
3736     variable warnings.
3737    
3738     3. Added the "runtest" target to Makefile.
3739    
3740     4. Set default compiler flag to -O2 rather than just -O.
3741    
3742    
3743 nigel 5 Version 1.01 19-Nov-97
3744     ----------------------
3745    
3746     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3747     like /([ab]*)*/, that is, for classes with more than one character in them.
3748    
3749     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3750     as /((?>a*))*/ (a PCRE_EXTRA facility).
3751    
3752    
3753     Version 1.00 18-Nov-97
3754     ----------------------
3755    
3756     1. Added compile-time macros to support systems such as SunOS4 which don't have
3757     memmove() or strerror() but have other things that can be used instead.
3758    
3759     2. Arranged that "make clean" removes the executables.
3760    
3761    
3762 nigel 3 Version 0.99 27-Oct-97
3763     ----------------------
3764    
3765     1. Fixed bug in code for optimizing classes with only one character. It was
3766     initializing a 32-byte map regardless, which could cause it to run off the end
3767     of the memory it had got.
3768    
3769     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3770    
3771    
3772     Version 0.98 22-Oct-97
3773     ----------------------
3774    
3775     1. Fixed bug in code for handling temporary memory usage when there are more
3776     back references than supplied space in the ovector. This could cause segfaults.
3777    
3778    
3779     Version 0.97 21-Oct-97
3780     ----------------------
3781    
3782     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3783    
3784     2. Optimized negated single characters not to use a bit map.
3785    
3786     3. Brought error texts together as macro definitions; clarified some of them;
3787     fixed one that was wrong - it said "range out of order" when it meant "invalid
3788     escape sequence".
3789    
3790     4. Changed some char * arguments to const char *.
3791    
3792     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3793    
3794     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3795     pcretest.
3796    
3797    
3798     Version 0.96 16-Oct-97
3799     ----------------------
3800    
3801     1. Added a simple "pgrep" utility to the distribution.