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Revision 524 - (hide annotations) (download)
Mon May 24 17:06:28 2010 UTC (4 years, 4 months ago) by ph10
File size: 187604 byte(s)
Make pcre_study() recognize \h, \v, and \R.

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