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Revision 536 - (hide annotations) (download)
Mon Jun 7 16:39:32 2010 UTC (4 years, 2 months ago) by ph10
File size: 187985 byte(s)
Reverse pcreposix.c #include patch; doesn't work on Windows.

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