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Revision 565 - (hide annotations) (download)
Sun Oct 31 18:18:48 2010 UTC (4 years, 5 months ago) by ph10
File size: 193188 byte(s)
Added parentheses argument to -o and --only-matching options of pcregrep.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 550 Version 8.11 10-Oct-2010
5     ------------------------
7     1. (*THEN) was not working properly if there were untried alternatives prior
8     to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9     backtracked to try for "b" instead of moving to the next alternative branch
10     at the same level (in this case, to look for "c"). The Perl documentation
11     is clear that when (*THEN) is backtracked onto, it goes to the "next
12     alternative in the innermost enclosing group".
13 ph10 551
14     2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15     such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
16     result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17     (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18     (*THEN).
19 ph10 552
20     3. If \s appeared in a character class, it removed the VT character from
21     the class, even if it had been included by some previous item, for example
22     in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
23     of \s, but is part of the POSIX "space" class.)
24 ph10 553
25     4. A partial match never returns an empty string (because you can always
26     match an empty string at the end of the subject); however the checking for
27     an empty string was starting at the "start of match" point. This has been
28     changed to the "earliest inspected character" point, because the returned
29     data for a partial match starts at this character. This means that, for
30     example, /(?<=abc)def/ gives a partial match for the subject "abc"
31     (previously it gave "no match").
32 ph10 550
33 ph10 553 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
34     of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
35     previously a full match would be given. However, setting PCRE_PARTIAL_HARD
36     has an implication that the given string is incomplete (because a partial
37     match is preferred over a full match). For this reason, these items now
38     give a partial match in this situation. [Aside: previously, the one case
39     /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
40     match rather than a full match, which was wrong by the old rules, but is
41     now correct.]
42 ph10 556
43     6. There was a bug in the handling of #-introduced comments, recognized when
44     PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
45     If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
46     UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
47     scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
48     but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
49     places in pcre_compile().
51     7. Related to (6) above, when pcre_compile() was skipping #-introduced
52     comments when looking ahead for named forward references to subpatterns,
53     the only newline sequence it recognized was NL. It now handles newlines
54     according to the set newline convention.
55 ph10 558
56     8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
57     former, but used strtoul(), whereas pcretest avoided strtoul() but did not
58     cater for a lack of strerror(). These oversights have been fixed.
59 ph10 561
60     9. Added --match-limit and --recursion-limit to pcregrep.
61 ph10 550
62 ph10 563 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
63 ph10 553
64 ph10 564 11. When the -o option was used, pcregrep was setting a return code of 1, even
65     when matches were found, and --line-buffered was not being honoured.
66 ph10 565
67     12. Added an optional parentheses number to the -o and --only-matching options
68     of pcregrep.
69 ph10 563
70 ph10 564
71 ph10 548 Version 8.10 25-Jun-2010
72 ph10 510 ------------------------
74 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
75 ph10 510 THEN.
77 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
78 ph10 510
79 ph10 535 3. Inside a character class, \B is treated as a literal by default, but
80     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
81 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
82 ph10 535
83     4. Inside a character class, PCRE always treated \R and \X as literals,
84 ph10 513 whereas Perl faults them if its -w option is set. I have changed PCRE so
85     that it faults them when PCRE_EXTRA is set.
86 ph10 535
87 ph10 514 5. Added support for \N, which always matches any character other than
88     newline. (It is the same as "." when PCRE_DOTALL is not set.)
89 ph10 535
90 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
91 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
92 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
93 ph10 535 result to (void) does not stop the warnings; a more elaborate fudge is
94     needed. I've used a macro to implement this.
95 ph10 512
96 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
98 ph10 517 8. Added four artifical Unicode properties to help with an option to make
99 ph10 518 \s etc use properties (see next item). The new properties are: Xan
100     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
101 ph10 535
102 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
103 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
104 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
105     REG_UCP to make it available via the POSIX interface.
106 ph10 513
107 ph10 535 10. Added --line-buffered to pcregrep.
109     11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
110     studied, and the match started with a letter with a code point greater than
111 ph10 520 127 whose first byte was different to the first byte of the other case of
112 ph10 545 the letter, the other case of this starting letter was not recognized
113 ph10 536 (#976).
114 ph10 535
115 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
116 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
117 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
118     not have actually happened in practice until change 8 above was made (it
119 ph10 523 added property types that matched character-matching opcodes).
120 ph10 535
121 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
122 ph10 535 possible starting bytes for non-anchored patterns.
124 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
125 ph10 535 \R, and also a number of cases that involve Unicode properties, both
126 ph10 532 explicit and implicit when PCRE_UCP is set.
127 ph10 529
128 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
129 ph10 535 input, it could crash or give wrong results if characters with values
130     greater than 0xc0 were present in the subject string. (Detail: it assumed
131 ph10 529 UTF-8 input when processing these items.)
132 ph10 535
133 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
134     size_t is 64-bit (#991).
135 ph10 535
136 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
137     --disable-stack-for-recursion (#990).
138 ph10 545
139 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
140 ph10 545 the end, a newline was missing in the output.
142     19. The default pcre_chartables.c file recognizes only ASCII characters (values
143     less than 128) in its various bitmaps. However, there is a facility for
144     generating tables according to the current locale when PCRE is compiled. It
145     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
146     characters, are recognized by isspace() and therefore were getting set in
147 ph10 541 these tables, and indeed these tables seem to approximate to ISO 8859. This
148     caused a problem in UTF-8 mode when pcre_study() was used to create a list
149     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
150     which of course cannot start UTF-8 characters. I have changed the code so
151     that only real ASCII characters (less than 128) and the correct starting
152 ph10 545 bytes for UTF-8 encodings are set for characters greater than 127 when in
153 ph10 541 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
154     altogether.)
155 ph10 545
156 ph10 541 20. Added the /T option to pcretest so as to be able to run tests with non-
157     standard character tables, thus making it possible to include the tests
158 ph10 545 used for 19 above in the standard set of tests.
160     21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
161     reference to a subpattern the other side of a comment that contains an
162     opening parenthesis caused either an internal compiling error, or a
163 ph10 544 reference to the wrong subpattern.
164 ph10 517
165 ph10 520
166 ph10 508 Version 8.02 19-Mar-2010
167 ph10 491 ------------------------
169     1. The Unicode data tables have been updated to Unicode 5.2.0.
171 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
172     configured.
173 ph10 507
174 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
175 ph10 507 original author of that file, following a query about its status.
177     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
178 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
179 ph10 507
180 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
181     quantifier applied to a forward-referencing subroutine call, could compile
182     incorrect code or give the error "internal error: previously-checked
183     referenced subpattern not found".
184 ph10 507
185     6. Both MS Visual Studio and Symbian OS have problems with initializing
186 ph10 497 variables to point to external functions. For these systems, therefore,
187     pcre_malloc etc. are now initialized to local functions that call the
188     relevant global functions.
189 ph10 507
190 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
191     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
192 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
193     the lengths are correct (equal to the number of opcodes).
195     8. Following on from 7, I added a similar kludge to check the length of the
196     eint vector in pcreposix.c.
198     9. Error texts for pcre_compile() are held as one long string to avoid too
199     much relocation at load time. To find a text, the string is searched,
200 ph10 499 counting zeros. There was no check for running off the end of the string,
201     which could happen if a new error number was added without updating the
202 ph10 507 string.
204     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
206 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
207 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
208     \K is "not well defined" if used in an assertion. PCRE now accepts it if
209     the assertion is positive, but not if it is negative.
211 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
212 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
213     implementation of support for (*MARK) will need an extra pointer on the
214 ph10 501 stack; I have reserved it now, so that the stack frame size does not
215     decrease.
216 ph10 507
217     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
218     item in branch that calls a recursion is a subroutine call - as in the
219 ph10 503 second branch in the above example - was incorrectly given the compile-
220     time error "recursive call could loop indefinitely" because pcre_compile()
221 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
223 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
224 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
225 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
226 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
227 ph10 491
228 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
229 ph10 492
230 ph10 507
231 ph10 489 Version 8.01 19-Jan-2010
232     ------------------------
233 ph10 471
234     1. If a pattern contained a conditional subpattern with only one branch (in
235 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
236 ph10 473 computed the wrong minimum data length (which is of course zero for such
237 ph10 489 subpatterns). This could cause incorrect "no match" results.
238 ph10 473
239     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
240 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
241     "internal error: code overflow at offset...". This happened only when
242 ph10 473 the reset was to the original external option setting. (An optimization
243     abstracts leading options settings into an external setting, which was the
244 ph10 472 cause of this.)
245 ph10 471
246 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
247     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
248     assertion pattern did not match (meaning that the assertion was true), it
249     was incorrectly treated as false if the SKIP had been reached during the
250     matching. This also applied to assertions used as conditions.
251 ph10 471
252 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
253     assertion subpattern, including such a pattern used as a condition,
254     unpredictable results occurred, instead of the error return
256 ph10 478
257 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
258     situation when an empty string is matched. It now does the fancy magic
259 ph10 478 stuff that is necessary.
261     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
262 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
263 ph10 478
264 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
265     as part of something else:
266 ph10 478
267     (a) Change DEBUG to PCRE_DEBUG.
269     (b) In pcre_compile(), rename the member of the "branch_chain" structure
270     called "current" as "current_branch", to prevent a collision with the
271 ph10 475 Linux macro when compiled as a kernel module.
272 ph10 478
273     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
274     prevent a collision with the Linux macro when compiled as a kernel
275 ph10 475 module.
276 ph10 478
277 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
278     cast potentially large values to (double). This has been changed to that
279 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
280     instead, thus avoiding the use of floating point arithmetic. (There is no
281     other use of FP in PCRE.) If int64_t is not found, the fallback is to
282     double.
284     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
285 ph10 476 2005 (difference between two addresses compared to an unsigned value).
286 ph10 473
287 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
288     custom one, because of the following reported problem in Windows:
289 ph10 473
290 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
291 ph10 489 under Win32.
292 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
293 ph10 489 therefore missing the function definition.
294 ph10 478 - The compiler thus generates a "C" signature for the test function.
295     - The linker fails to find the "C" function.
296     - PCRE fails to configure if asked to do so against libbz2.
297 ph10 486
298 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
299     messages were output:
300 ph10 478
301 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
302     rerunning libtoolize, to keep the correct libtool macros in-tree.
303     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
304 ph10 486
305 ph10 479 I have done both of these things.
306 ph10 486
307 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
308 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
309     runaway infinite recursion. I updated the discussion in the pcrestack man
310     page.
312     13. Now that we have gone to the x.xx style of version numbers, the minor
313     version may start with zero. Using 08 or 09 is a bad idea because users
314     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
315     interpreted as invalid octal numbers. I've updated the previous comment in
316     configure.ac, and also added a check that gives an error if 08 or 09 are
317 ph10 481 used.
318 ph10 486
319 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
320 ph10 483 causing partial matching to fail when the end of the subject matched \W
321     in a UTF-8 pattern where \W was quantified with a minimum of 3.
322 ph10 486
323 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
324 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
325 ph10 483 their definitions. The declarations used "const uschar *" and the
326     definitions used USPTR. Even though USPTR is normally defined as "const
327     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
328     reported that: "This difference in casting confuses some C++ compilers, for
329     example, SunCC recognizes above declarations as different functions and
330 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
331 ph10 483 USPTR.
332 ph10 486
333     16. GNU libtool is named differently on some systems. The autogen.sh script now
334 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
335     (FreeBSD).
336 ph10 478
337 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
338     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
339     comment: "Figure out how to create a longlong from a string: strtoll and
340     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
341     instance, but it only takes 2 args instead of 3!"
342 ph10 479
343 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
344     specification, with a corresponding code fix. A pattern such as
345     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
346     refers, was giving matches when it shouldn't. For example, xa=xaaa would
347     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
348     same bug. Such groups have to be quantified to be useful, or contained
349     inside another quantified group. (If there's no repetition, the reference
350     can never match.) The problem arises because, having left the group and
351     moved on to the rest of the pattern, a later failure that backtracks into
352     the group uses the captured value from the final iteration of the group
353     rather than the correct earlier one. I have fixed this in PCRE by forcing
354     any group that contains a reference to itself to be an atomic group; that
355     is, there cannot be any backtracking into it once it has completed. This is
356     similar to recursive and subroutine calls.
357 ph10 486
358 ph10 488
359 ph10 469 Version 8.00 19-Oct-09
360 ph10 418 ----------------------
362     1. The table for translating pcre_compile() error codes into POSIX error codes
363 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
364     being within the table. This could lead to an OK return being given in
365 ph10 418 error.
366 ph10 461
367     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
368     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
369     in a Windows environment.
371 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
372     zero, as does GNU grep. However, pcregrep was also printing all files when
373     --files-with-matches was added. Now, when both options are given, it prints
374     counts only for those files that have at least one match. (GNU grep just
375 ph10 461 prints the file name in this circumstance, but including the count seems
376     more useful - otherwise, why use --count?) Also ensured that the
377 ph10 420 combination -clh just lists non-zero counts, with no names.
378 ph10 461
379     4. The long form of the pcregrep -F option was incorrectly implemented as
380     --fixed_strings instead of --fixed-strings. This is an incompatible change,
381     but it seems right to fix it, and I didn't think it was worth preserving
382     the old behaviour.
384     5. The command line items --regex=pattern and --regexp=pattern were not
385 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
386 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
387 ph10 422 which are compatible with GNU grep; these now work.
388 ph10 461
389     6. No libpcreposix.pc file was created for pkg-config; there was just
390 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
391 ph10 461
392 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
393 ph10 461 when UCP support is not needed, by modifying the Python script that
394 ph10 425 generates it from Unicode data files. This should not matter if the module
395     is correctly used as a library, but I received one complaint about 50K of
396     unwanted data. My guess is that the person linked everything into his
397     program rather than using a library. Anyway, it does no harm.
398 ph10 461
399 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
400 ph10 461 was a minimum greater than 1 for a wide character in a possessive
401 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
402     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
403     character. Chaos in the form of incorrect output or a compiling loop could
404     result.
405 ph10 461
406 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
407 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
408 ph10 426 partially matched by this function. In addition, if there are at least two
409 ph10 435 slots in the offset vector, the offset of the earliest inspected character
410     for the match and the offset of the end of the subject are set in them when
411 ph10 461 PCRE_ERROR_PARTIAL is returned.
413 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
414     synonymous with PCRE_PARTIAL, for backwards compatibility, and
415     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
416 ph10 462 and may be more useful for multi-segment matching.
417 ph10 461
418     11. Partial matching with pcre_exec() is now more intuitive. A partial match
419     used to be given if ever the end of the subject was reached; now it is
420     given only if matching could not proceed because another character was
421     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
422     string "Z", which now yields "no match" instead of "partial match". In the
423     case of pcre_dfa_exec(), "no match" is given if every matching path for the
424     final character ended with (*FAIL).
426 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
427 ph10 461 if the pattern had a "must contain" character that was already found in the
428 ph10 428 earlier partial match, unless partial matching was again requested. For
429     example, with the pattern /dog.(body)?/, the "must contain" character is
430     "g". If the first part-match was for the string "dog", restarting with
431 ph10 435 "sbody" failed. This bug has been fixed.
432 ph10 461
433     13. The string returned by pcre_dfa_exec() after a partial match has been
434     changed so that it starts at the first inspected character rather than the
435     first character of the match. This makes a difference only if the pattern
436     starts with a lookbehind assertion or \b or \B (\K is not supported by
437     pcre_dfa_exec()). It's an incompatible change, but it makes the two
438 ph10 435 matching functions compatible, and I think it's the right thing to do.
439 ph10 461
440 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
441 ph10 461 so that the demonstration program is easily available in environments where
442     PCRE has not been installed from source.
444 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
445 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
446     library.
447 ph10 461
448 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
449 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
450 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
451 ph10 433 these options useful.
452 ph10 461
453     17. If a caller to the POSIX matching function regexec() passes a non-zero
454 ph10 438 value for nmatch with a NULL value for pmatch, the value of
455 ph10 461 nmatch is forced to zero.
457 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
458 ph10 461 the diff command, as RunTest does. It now checks in the same way as
459 ph10 437 RunTest, and also checks for the -b option.
460 ph10 461
461 ph10 438 19. If an odd number of negated classes containing just a single character
462     interposed, within parentheses, between a forward reference to a named
463 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
464     an internal error, complaining that it could not find the referenced
465 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
466 ph10 461 [The bug was that it was starting one character too far in when skipping
467     over the character class, thus treating the ] as data rather than
468     terminating the class. This meant it could skip too much.]
470 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
471 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
472 ph10 442 to have an empty string match not at the start, even when the pattern is
473 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
475 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
476 ph10 461 than the maximum at the outer level, the higher number was returned, but
477     with unset values at the outer level. The correct (outer level) value is
478 ph10 446 now given.
479 ph10 461
480 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
481     PCRE did not set those parentheses (unlike Perl). I have now found a way to
482     make it do so. The string so far is captured, making this feature
483     compatible with Perl.
484 ph10 461
485     23. The tests have been re-organized, adding tests 11 and 12, to make it
486 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
487 ph10 461
488 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
489 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
490     does. Neither allows recursion.
492     25. I finally figured out how to implement a request to provide the minimum
493     length of subject string that was needed in order to match a given pattern.
494     (It was back references and recursion that I had previously got hung up
495     on.) This code has now been added to pcre_study(); it finds a lower bound
496 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
497     bound, but using it to avoid searching strings that are too short does give
498     some useful speed-ups. The value is available to calling programs via
499     pcre_fullinfo().
500 ph10 461
501 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
502     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
503     study optimizations had never been tested with that matching function.
504     Oops. What is worse, even when it was passed study data, there was a bug in
505     pcre_dfa_exec() that meant it never actually used it. Double oops. There
506     were also very few tests of studied patterns with pcre_dfa_exec().
507 ph10 461
508 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
509     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
510     on the other side of the coin, they are no longer allowed to have different
511     names, because these cannot be distinguished in PCRE, and this has caused
512     confusion. (This is a difference from Perl.)
513 ph10 461
514     28. When duplicate subpattern names are present (necessarily with different
515     numbers, as required by 27 above), and a test is made by name in a
516     conditional pattern, either for a subpattern having been matched, or for
517     recursion in such a pattern, all the associated numbered subpatterns are
518 ph10 459 tested, and the overall condition is true if the condition is true for any
519     one of them. This is the way Perl works, and is also more like the way
520     testing by number works.
521 ph10 418
522 ph10 461
523 ph10 412 Version 7.9 11-Apr-09
524 ph10 376 ---------------------
526 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
527 ph10 376 (pcretest), all targets were linked against these libraries. This included
528     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
529     libraries. This caused unwanted dependencies to be created. This problem
530 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
531 ph10 376 pcretest is linked with readline.
532 ph10 392
533 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
534     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
535     moved outside it again, because FALSE and TRUE are already defined in AIX,
536     but BOOL is not.
537 ph10 392
538     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
539 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
540 ph10 392
541 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
542     hyphens) following file names and line numbers when outputting matching
543 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
544 ph10 376 wording for the --colour (or --color) option.
545 ph10 392
546 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
547     was not coloured; this is different to GNU grep, so I have changed it to be
548     the same.
549 ph10 392
550 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
551 ph10 392 each matching line was coloured. Now it goes on to look for further matches
552     of any of the test patterns, which is the same behaviour as GNU grep.
554     7. A pattern that could match an empty string could cause pcregrep to loop; it
555     doesn't make sense to accept an empty string match in pcregrep, so I have
556 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
557     seems to be how GNU grep behaves.
558 ph10 392
559 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
560 ph10 392 start or after a newline", because the conditional assertion was not being
561     correctly handled. The rule now is that both the assertion and what follows
562     in the first alternative must satisfy the test.
564 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
565 ph10 399 condition was an assertion, PCRE could crash during matching, both with
566     pcre_exec() and pcre_dfa_exec().
567 ph10 392
568     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
569     used for matching.
571     11. Unicode property support in character classes was not working for
572 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
573 ph10 388
574 ph10 392 12. Added the -M command line option to pcretest.
576 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
577 ph10 389
578     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
579 ph10 390
580 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
581 ph10 390 wrapper.
582 ph10 392
583 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
584 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
585 ph10 391 string constants.
586 ph10 405
587 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
588     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
589 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
590     these, but not everybody uses configure.
592     19. A conditional group that had only one branch was not being correctly
593     recognized as an item that could match an empty string. This meant that an
594     enclosing group might also not be so recognized, causing infinite looping
595     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
596     with the subject "ab", where knowledge that the repeated group can match
597 ph10 396 nothing is needed in order to break the loop.
598 ph10 405
599 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
600 ph10 405 exec(), but without supplying a callout function, matching went wrong.
602     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
603     leak if the size of the offset vector was greater than 30. When the vector
604     is smaller, the saved offsets during recursion go onto a local stack
605     vector, but for larger vectors malloc() is used. It was failing to free
606     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
607 ph10 400 error, in fact).
608 ph10 405
609 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
610 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
611     problem, but was untidy.
612 ph10 376
613 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
614     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
615     included within another project.
616 ph10 411
617 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
618     slightly modified by me:
619 ph10 411
620     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
621     not building pcregrep.
623 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
624 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
626 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
627     duplicate group numbers, could behave incorrectly or give incorrect errors,
628     because when scanning forward to find the reference group, PCRE was not
629     taking into account the duplicate group numbers. A pattern such as
630     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
631 ph10 411
632     26. Changed a few more instances of "const unsigned char *" to USPTR, making
633     the feature of a custom pointer more persuasive (as requested by a user).
634 ph10 416
635 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
636 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
637     pre-defined.
638 ph10 392
639 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
641 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
642     in the configuration summary.
643 ph10 405
644 ph10 411
645 ph10 374 Version 7.8 05-Sep-08
646 ph10 349 ---------------------
648     1. Replaced UCP searching code with optimized version as implemented for Ad
649     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
650 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
651     to 5 times on some simple patterns that I tested. Permission was given to
652     distribute the MultiStage2.py script that generates the tables (it's not in
653     the tarball, but is in the Subversion repository).
654 ph10 349
655 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
656     scripts.
657 ph10 358
658 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
659     a group with a zero qualifier. The result of the study could be incorrect,
660 ph10 358 or the function might crash, depending on the pattern.
662     4. Caseless matching was not working for non-ASCII characters in back
663 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
664 ph10 358 It now works when Unicode Property Support is available.
666 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
667     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
668     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
669 ph10 358 truncation.
670 ph10 349
671 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
673 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
674     pointers, in case they are 64-bit values.
675 ph10 371
676     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
677     test 2 if it fails.
679 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
680 ph10 371 and a #define of that name to empty if it is not externally set. This is to
681     allow users of MSVC to set it if necessary.
683     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
684 ph10 359 the convenience functions in the pcre_get.c source file.
685 ph10 371
686 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
687     could cause overwriting and/or a crash. This command provoked a crash in
688 ph10 371 some environments:
690     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
692 ph10 360 This potential security problem was recorded as CVE-2008-2371.
693 ph10 371
694 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
695     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
696 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
697 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
698     pcretest so that it places the subject at the end of its malloc-ed buffer.
699 ph10 371
700 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
701 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
703 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
704 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
705     first line. This applied both to normal and DFA matching.
707 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
708 ph10 371 /^[^d]*?$/8 failed to match "abc".
709 ph10 351
710 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
712     17. Make it more clear in the documentation that values returned from
713 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
714 ph10 357
715 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
716 ph10 368
717 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
718     supplied by Stefan Weber. I made a further small update for 7.8 because
719 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
720     replaced by pcre_ucd.c.
721 ph10 371
722 ph10 373
723 ph10 347 Version 7.7 07-May-08
724 ph10 321 ---------------------
726     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
727 ph10 345 a string to a long long, pretend we don't even have a long long." This is
728 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
729 ph10 345
730 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
731     pre-7.6 versions, which defined a global no_arg variable instead of putting
732 ph10 332 it in the RE class. (See also #8 below.)
733 ph10 345
734     3. Remove a line of dead code, identified by coverity and reported by Nuno
735     Lopes.
737 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
738 ph10 321
739 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
740 ph10 345 of files, instead of just to the final components.
742 ph10 324 (2) If there was more than one level of directory, the subdirectories were
743     skipped unless they satisfied the include/exclude conditions. This is
744     inconsistent with GNU grep (and could even be seen as contrary to the
745     pcregrep specification - which I improved to make it absolutely clear).
746     The action now is always to scan all levels of directory, and just
747     apply the include/exclude patterns to regular files.
748 ph10 345
749 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
750 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
752 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
753 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
754 ph10 326 doesn't support NULs in patterns.
755 ph10 345
756     7. Added some missing "const"s to declarations of static tables in
757     pcre_compile.c and pcre_dfa_exec.c.
759 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
760 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
761 ph10 345 first patch. And a third patch - this was a messy problem.)
762 ph10 321
763 ph10 345 9. Applied Craig's patch to remove the use of push_back().
765 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
766     matching function regexec().
767 ph10 345
768     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
769     which, however, unlike Perl's \g{...}, are subroutine calls, not back
770 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
771     Oniguruma does).
772 ph10 345
773     12. Previously, a group with a zero repeat such as (...){0} was completely
774 ph10 335 omitted from the compiled regex. However, this means that if the group
775     was called as a subroutine from elsewhere in the pattern, things went wrong
776 ph10 345 (an internal error was given). Such groups are now left in the compiled
777     pattern, with a new opcode that causes them to be skipped at execution
778 ph10 335 time.
779 ph10 345
780 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
781     to the way PCRE behaves:
782 ph10 345
783 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
784 ph10 345
785     (b) A back reference to an unmatched subpattern matches an empty string
786 ph10 336 (Perl fails the current match path).
787 ph10 345
788 ph10 341 (c) A data ] in a character class must be notated as \] because if the
789 ph10 345 first data character in a class is ], it defines an empty class. (In
790 ph10 341 Perl it is not possible to have an empty class.) The empty class []
791     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
792     The negative empty class [^] matches any one character, independently
793     of the DOTALL setting.
794 ph10 345
795     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
796 ph10 340 non-existent subpattern following a character class starting with ']' and
797     containing () gave an internal compiling error instead of "reference to
798     non-existent subpattern". Fortunately, when the pattern did exist, the
799 ph10 345 compiled code was correct. (When scanning forwards to check for the
800 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
801 ph10 345 the class, so got the count wrong. When actually compiling, the reference
802 ph10 340 was subsequently set up correctly.)
803 ph10 345
804 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
805 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
806     other assertions are supported. I have made pcre_dfa_exec() support
807     (*FAIL).
809 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
810 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
811     cannot be changed at match time, I realized I could make a small
812     improvement to matching performance by compiling OP_ALLANY instead of
813     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
814     on the OP_ANY path.
816     17. Compiling pcretest on Windows with readline support failed without the
817 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
818 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
820 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
821 ph10 345 ncurses library to be included for pcretest when ReadLine support is
822     requested, but also to allow for it to be overridden. This patch came from
823     Daniel Bergström.
824 ph10 347
825 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
826 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
827     any errors with the current Unicode tables. Thanks to Peter Kankowski for
828     spotting this.
829 ph10 324
830 ph10 332
831 ph10 319 Version 7.6 28-Jan-08
832 ph10 300 ---------------------
834 ph10 302 1. A character class containing a very large number of characters with
835     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
836     overflow.
837 ph10 309
838     2. Patch to cut out the "long long" test in pcrecpp_unittest when
839     HAVE_LONG_LONG is not defined.
841 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
842 ph10 304 bring them up to date and include new features. This patch includes:
843 ph10 309
844 ph10 304 - Fixed PH's badly added libz and libbz2 support.
845     - Fixed a problem with static linking.
846 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
847 ph10 304 - Fixed dftables problem and added an option.
848     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
850     - Added readline support for pcretest.
851 ph10 309 - Added an listing of the option settings after cmake has run.
853 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
854     "pcre.dll" under mingw when using Configure/Make. I added stuff to
855     Makefile.am that cause it to include this special target, without
856     affecting anything else. Note that the same mingw target plus all
857     the other distribution libraries and programs are now supported
858     when configuring with CMake (see 6 below) instead of with
859     Configure/Make.
860 ph10 309
861 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
862     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
863 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
864     solves the problem, but it does no harm.
865 ph10 313
866 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
867 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
868 ph10 314 with CMake, and also correct the comment about stack recursion.
869 ph10 313
870 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
871 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
872     of a program that users should build themselves after PCRE is installed, so
873     building it automatically is not really right. What is more, it gave
874 ph10 312 trouble in some build environments.
875 ph10 300
876 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
877 ph10 308
878 ph10 319
879 ph10 298 Version 7.5 10-Jan-08
880 ph10 263 ---------------------
882     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
883     values in parens when parsing an RE using the C++ wrapper."
884 ph10 286
885 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
886     Characters greater than 255 were excluded from the class instead of being
887     included.
888 ph10 286
889     3. The same bug as (2) above applied to negated POSIX classes such as
890 ph10 265 [:^space:].
891 ph10 286
892 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
893     defined or documented. It seems to have been a typo for PCRE_STATIC, so
894 ph10 286 I have changed it.
896 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
897 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
898     first named subpattern whose name started with "a" (in other words, the
899 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
900     expected" is now given for (?&) (a zero-length name), and this patch also
901     makes it give the same error for \k'' (previously it complained that that
902     was a reference to a non-existent subpattern).
903 ph10 286
904 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
905 ph10 286 this is right because (?- can be followed by option settings as well as by
906 ph10 269 digits. I have, however, made the messages clearer.
907 ph10 286
908 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
909     than the number used in the conditional) now cause a compile-time error.
910     This is actually not compatible with Perl, which accepts such patterns, but
911     treats the conditional as always being FALSE (as PCRE used to), but it
912     seems to me that giving a diagnostic is better.
913 ph10 286
914 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
915 ph10 275 and messages.
916 ph10 286
917     9. Fix two occurrences of "backslash" in comments that should have been
918     "backspace".
920     10. Remove two redundant lines of code that can never be obeyed (their function
921     was moved elsewhere).
923     11. The program that makes PCRE's Unicode character property table had a bug
924     which caused it to generate incorrect table entries for sequences of
925 ph10 277 characters that have the same character type, but are in different scripts.
926 ph10 286 It amalgamated them into a single range, with the script of the first of
927 ph10 277 them. In other words, some characters were in the wrong script. There were
928     thirteen such cases, affecting characters in the following ranges:
929 ph10 286
930 ph10 277 U+002b0 - U+002c1
931     U+0060c - U+0060d
932 ph10 286 U+0061e - U+00612
933 ph10 277 U+0064b - U+0065e
934     U+0074d - U+0076d
935     U+01800 - U+01805
936     U+01d00 - U+01d77
937     U+01d9b - U+01dbf
938     U+0200b - U+0200f
939     U+030fc - U+030fe
940     U+03260 - U+0327f
941     U+0fb46 - U+0fbb1
942     U+10450 - U+1049d
943 ph10 286
944 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
945     compatible with GNU grep in that, if there was more than one match in a
946     line, it showed only the first of them. It now behaves in the same way as
947     GNU grep.
948 ph10 286
949     13. If the -o and -v options were combined for pcregrep, it printed a blank
950     line for every non-matching line. GNU grep prints nothing, and pcregrep now
951     does the same. The return code can be used to tell if there were any
952     non-matching lines.
954 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
956     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
957 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
958 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
959     and both kinds of lookbehind were skipped).
961 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
962 ph10 284 inclusion of <windows.h> to before rather than after the definition of
963     INVALID_FILE_ATTRIBUTES (patch from David Byron).
964 ph10 263
965 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
966 ph10 286 character property caused pcre_compile() to compile bad code, which led at
967     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
968     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
969     caused the error; without that there was no problem.
970 ph10 263
971 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
972 ph10 286
973 ph10 289 19. Added --enable-pcretest-libreadline.
974 ph10 286
975 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
976 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
977 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
978     later patch that removed the other one (the right fix) and added unit tests
979     that check the return values (which was not done before).
980 ph10 292
981 ph10 291 21. Several CMake things:
982 ph10 287
983 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
984 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
985 ph10 288
986 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
987     linked with the newly-built libraries, not previously installed ones.
988 ph10 291
990 ph10 298
991     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
992     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
993     UTF-8 newline character). The key issue is that the pattern starts .*;
994     this means that the match must be either at the beginning, or after a
995     newline. The bug was in the code for advancing after a failed match and
996     checking that the new position followed a newline. It was not taking
997 ph10 294 account of UTF-8 characters correctly.
998 ph10 298
999     23. PCRE was behaving differently from Perl in the way it recognized POSIX
1000     character classes. PCRE was not treating the sequence [:...:] as a
1001     character class unless the ... were all letters. Perl, however, seems to
1002     allow any characters between [: and :], though of course it rejects as
1003     unknown any "names" that contain non-letters, because all the known class
1004     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1005     for example, whereas PCRE did not - it did not recognize a POSIX character
1006     class. This seemed a bit dangerous, so the code has been changed to be
1007     closer to Perl. The behaviour is not identical to Perl, because PCRE will
1008     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1009     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1010     Perl does, and where it didn't before.
1012 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1013     Windows environments %n is disabled by default.
1014 ph10 292
1016 ph10 260 Version 7.4 21-Sep-07
1017 ph10 230 ---------------------
1019     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1020 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
1021     LF". That isn't really right - the whole point of the change was to try to
1022     help when there was an actual mention of one of the two characters. So now
1023     the change happens only if \r or \n (or a literal CR or LF) character is
1024 ph10 230 encountered.
1025 ph10 231
1026     2. The 32-bit options word was also used for 6 internal flags, but the numbers
1027     of both had grown to the point where there were only 3 bits left.
1028     Fortunately, there was spare space in the data structure, and so I have
1029     moved the internal flags into a new 16-bit field to free up more option
1030 ph10 230 bits.
1031 ph10 231
1032     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1033     but did not set the internal JCHANGED flag - either of these is enough to
1034     control the way the "get" function works - but the PCRE_INFO_JCHANGED
1035     facility is supposed to tell if (?J) was ever used, so now (?J) at the
1036 ph10 230 start sets both bits.
1038 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
1039     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1040 ph10 230
1041 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
1043     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1044 ph10 233 compatibility, even though it is no longer used.
1045 ph10 243
1046     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1047 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1048 ph10 259 windows.h file is present (where different names are used). [This was
1049 ph10 257 reversed later after testing - see 16 below.]
1050 ph10 243
1051     8. Changed all #include <config.h> to #include "config.h". There were also
1052 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
1053 ph10 243
1054 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
1055 ph10 243 sequence off the lines that it output.
1057     10. It was pointed out to me that arrays of string pointers cause lots of
1058     relocations when a shared library is dynamically loaded. A technique of
1059     using a single long string with a table of offsets can drastically reduce
1060     these. I have refactored PCRE in four places to do this. The result is
1061 ph10 240 dramatic:
1062 ph10 243
1063 ph10 240 Originally: 290
1064     After changing UCP table: 187
1065 ph10 243 After changing error message table: 43
1066 ph10 240 After changing table of "verbs" 36
1067     After changing table of Posix names 22
1068 ph10 243
1069 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
1070 ph10 247
1071 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1072 ph10 247 unicode-properties was also set.
1074 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1075 ph10 231
1076 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1077     checked only for CRLF.
1078 ph10 233
1079 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
1081 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1082 ph10 253
1083 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1084 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1085     entirely. This removes changes made in 7 above.
1086 ph10 256
1087 ph10 261 17. The CMake files have been updated, and there is now more information about
1088     building with CMake in the NON-UNIX-USE document.
1089 ph10 257
1090 ph10 261
1091 ph10 228 Version 7.3 28-Aug-07
1092 ph10 157 ---------------------
1094 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1095     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1096     brackets there is not right, since it causes compilers to look for an
1097     installed pcre.h, not the version that is in the source that is being
1098     compiled (which of course may be different). I have changed it back to:
1099 ph10 197
1100 ph10 189 #include "pcre.h"
1101 ph10 197
1102     I have a vague recollection that the change was concerned with compiling in
1103     different directories, but in the new build system, that is taken care of
1104     by the VPATH setting the Makefile.
1106 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1107     when the subject happened to end in the byte 0x85 (e.g. if the last
1108     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1109     characters but of course it shouldn't be taken as a newline when it is part
1110     of another character. The bug was that, for an unlimited repeat of . in
1111     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1112     characters when looking for a newline.
1113 ph10 197
1114     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1116     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1117     in debug output.
1119 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1120     long printing in the pcrecpp unittest when running under MinGW.
1121 ph10 189
1122 ph10 197 6. ESC_K was left out of the EBCDIC table.
1123 ph10 189
1124 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1125     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1126     limit also applies to "virtual nesting" when a pattern is recursive, and in
1127     this case 1000 isn't so big. I have been able to remove this limit at the
1128     expense of backing off one optimization in certain circumstances. Normally,
1129     when pcre_exec() would call its internal match() function recursively and
1130     immediately return the result unconditionally, it uses a "tail recursion"
1131     feature to save stack. However, when a subpattern that can match an empty
1132     string has an unlimited repetition quantifier, it no longer makes this
1133     optimization. That gives it a stack frame in which to save the data for
1134     checking that an empty string has been matched. Previously this was taken
1135     from the 1000-entry workspace that had been reserved. So now there is no
1136     explicit limit, but more stack is used.
1137 ph10 189
1138 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1139     syntax that is required for Windows, and which was going wrong for the
1140     pcreposix and pcrecpp parts of the library. These were overlooked when this
1141     problem was solved for the main library.
1142 ph10 197
1143 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1144     the size of patterns that contain repeated groups with explicit upper
1145     limits. As the maximum quantifier is 65535, the maximum group length was
1146     set at 30,000 so that the product of these two numbers did not overflow a
1147     32-bit integer. However, it turns out that people want to use groups that
1148     are longer than 30,000 bytes (though not repeat them that many times).
1149     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1150     made it possible to implement the integer overflow checks in a much more
1151     dynamic way, which I have now done. The artificial limitation on group
1152     length has been removed - we now have only the limit on the total length of
1153     the compiled pattern, which depends on the LINK_SIZE setting.
1154 ph10 208
1155     10. Fixed a bug in the documentation for get/copy named substring when
1156     duplicate names are permitted. If none of the named substrings are set, the
1157     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1158     empty string.
1160     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1161     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1162     because the ] is interpreted as the first data character and the
1163     terminating ] is not found. PCRE has been made compatible with Perl in this
1164     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1165     cause memory overwriting.
1167 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1168     string has been matched (to stop an infinite loop). It was not recognizing
1169 ph10 208 a conditional subpattern that could match an empty string if that
1170 ph10 206 subpattern was within another subpattern. For example, it looped when
1171 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1172 ph10 206 condition was not nested. This bug has been fixed.
1173 ph10 208
1174 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1175     past the start of the subject in the presence of bytes with the top bit
1176     set, for example "\x8aBCD".
1177 ph10 211
1178 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1179     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1180 ph10 200
1181 ph10 211 14. Optimized (?!) to (*FAIL).
1182 ph10 202
1183 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1184     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1185     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1186     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1187     does: it's just the validity check that is more restrictive.
1188 ph10 220
1189     16. Inserted checks for integer overflows during escape sequence (backslash)
1190     processing, and also fixed erroneous offset values for syntax errors during
1191     backslash processing.
1193 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1194 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1196 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1197     caused an overrun.
1198 ph10 220
1199     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1200     something other than just ASCII characters) inside a group that had an
1201     unlimited repeat caused a loop at compile time (while checking to see
1202     whether the group could match an empty string).
1204 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1205     [\P{Any}] did so. (Error in the code for printing property names.)
1206 ph10 210
1207 ph10 220 21. An orphan \E inside a character class could cause a crash.
1209     22. A repeated capturing bracket such as (A)? could cause a wild memory
1210 ph10 218 reference during compilation.
1211 ph10 220
1212     23. There are several functions in pcre_compile() that scan along a compiled
1213     expression for various reasons (e.g. to see if it's fixed length for look
1214 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1215 ph10 220 present in the pattern. These operators have additional parameters compared
1216     with \d, etc, and these were not being taken into account when moving along
1217 ph10 218 the compiled data. Specifically:
1218 ph10 220
1219     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1220     length.
1222     (b) An item such as \pL+ within a repeated group could cause crashes or
1223 ph10 218 loops.
1224 ph10 220
1225 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1226 ph10 220 "reference to non-existent subpattern" error.
1228 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1230 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1231 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1232 ph10 211
1233 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1234 ph10 218
1235 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1236 ph10 223 character were causing crashes (broken optimization).
1237 ph10 227
1238 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1239 ph10 227 \p or \P) caused a compile-time loop.
1241 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1242     break. For example, the unstudied pattern [\r\n]A does not match the string
1243     "\r\nA" because change 7.0/46 below moves the current point on by two
1244     characters after failing to match at the start. However, the pattern \nA
1245 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1246     the same is true. There doesn't seem any very clean way out of this, but
1247     what I have chosen to do makes the common cases work: PCRE now takes note
1248     of whether there can be an explicit match for \r or \n anywhere in the
1249     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1250     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1251     pattern has explicit CR or LF references.
1252 ph10 222
1253 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1254 ph10 223
1255 ph10 227
1256 ph10 189 Version 7.2 19-Jun-07
1257     ---------------------
1259 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1260     which is apparently normally available under Windows.
1261 ph10 159
1262     2. Re-jig the pcregrep tests with different newline settings in an attempt
1263     to make them independent of the local environment's newline setting.
1264 ph10 157
1265 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1266 ph10 165
1267 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1268     was not 2, because the output contained actual offsets. The recent new
1269 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1270     usable with all link sizes.
1272 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1273     stack recursion. This gives a massive performance boost under BSD, but just
1274 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1275 ph10 164 in all cases.
1276 ph10 172
1277 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1278 ph10 172
1279 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1280     recursion call. It refers to the nth most recently opened parentheses.
1281 ph10 172
1282 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1283 ph10 172 to be opened parentheses.
1285     (c) Conditions that refer to capturing parentheses can be specified
1286 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1287 ph10 172
1288 ph10 168 (d) \K resets the start of the current match so that everything before
1289 ph10 172 is not part of it.
1291 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1292 ph10 172
1293 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1294 ph10 172 reference syntax.
1295 ph10 182
1296 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1297 ph10 182 alternative starts with the same number.
1298 ph10 172
1299 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1301 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1304     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1305     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1306 ph10 170 for detecting groups that can match an empty string.
1307 ph10 159
1308 ph10 172 9. A pattern with a very large number of alternatives (more than several
1309     hundred) was running out of internal workspace during the pre-compile
1310     phase, where pcre_compile() figures out how much memory will be needed. A
1311     bit of new cunning has reduced the workspace needed for groups with
1312     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1313     workspace instead of running out of the 4096 that are available.
1314 ph10 182
1315 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1316 ph10 172
1317 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1318     The report of the bug said:
1319 ph10 182
1320 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1321     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1322 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1323 ph10 185
1324 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1325 ph10 185 it matched the wrong number of bytes.
1326 ph10 172
1327 ph10 179
1328 ph10 155 Version 7.1 24-Apr-07
1329 ph10 98 ---------------------
1331 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1332 ph10 122 that is more "standard", making use of automake and other Autotools. There
1333 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1334     on this.
1335 ph10 111
1336     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1337     for recursive directory scanning broke on some systems because the files
1338     are not scanned in any specific order and on different systems the order
1339     was different. A call to "sort" has been inserted into RunGrepTest for the
1340     approprate test as a short-term fix. In the longer term there may be an
1341 ph10 100 alternative.
1342 ph10 111
1343 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1344 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1345     people do their own conversions for various reasons). The problems
1346     concerned the use of low-level troff macros .br and .in. I have therefore
1347     removed all such uses from the man pages (some were redundant, some could
1348 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1349     HTML has been updated to handle .nf/.fi and to complain if it encounters
1350     .br or .in.
1351 ph10 111
1352 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1353 ph10 123 arranged for config.h to be included in the distribution, with the name
1354 ph10 111 config.h.generic, for the benefit of those who have to compile without
1355     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1357     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1358     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1359 ph10 127 makevp.bat for the current PCRE, using the additional files
1360 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1361 ph10 111
1362     6. A Windows user reported a minor discrepancy with test 2, which turned out
1363     to be caused by a trailing space on an input line that had got lost in his
1364 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1365 ph10 111
1366 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1367 ph10 111 that is needed.
1369 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1370     as "const" (a) because they are and (b) because it helps the PHP
1371     maintainers who have recently made a script to detect big data structures
1372 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1373     to update Builducptable as well, so it won't revert if ucptable.h is ever
1374 ph10 105 re-created.
1375 ph10 111
1376     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1377 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1378 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1379     support is not required. This saves 1.5-2K of code, which is important in
1380 ph10 107 some applications.
1381 ph10 111
1382 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1383 ph10 111 so as not to refer to the tables, even though these functions will never be
1384     called when UTF-8 support is disabled. Otherwise there are problems with a
1385     shared library.
1387 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1389     (a) It was defining its arguments as char * instead of void *.
1391 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1392     a long time ago when I wrote it, but is no longer the case.
1394 ph10 118 The emulated memove() is provided for those environments that have neither
1395 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1396 ph10 118 is clearly not the case, as these two bugs were recently reported.
1397 ph10 123
1398 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1399 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1400     pages, and it removes trailing spaces from listed files. It also creates
1401     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1402     case, it wraps all the #defines with #ifndefs. This script should be run
1403 ph10 111 before "make dist".
1404 ph10 123
1405 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1406     with Unicode property support.
1407 ph10 123
1408     (a) For a maximizing quantifier, if the two different cases of the
1409     character were of different lengths in their UTF-8 codings (there are
1410     some cases like this - I found 11), and the matching function had to
1411 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1412     were both the same length.
1413 ph10 123
1414     (b) When PCRE was configured to use the heap rather than the stack for
1415     recursion during matching, it was not correctly preserving the data for
1416     the other case of a UTF-8 character when checking ahead for a match
1417     while processing a minimizing repeat. If the check also involved
1418 ph10 115 matching a wide character, but failed, corruption could cause an
1419     erroneous result when trying to check for a repeat of the original
1420     character.
1421 ph10 123
1422 ph10 116 13. Some tidying changes to the testing mechanism:
1423 ph10 98
1424 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1425     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1426 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1427     this for UTF-8.) The configure.ac script no longer substitutes the
1428     relevant variables.
1430 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1431     with length and offset values. This means that the output is different
1432     for different internal link sizes. Test 2 is skipped for link sizes
1433     other than 2 because of this, bypassing the problem. Unfortunately,
1434     there was also a test in test 3 (the locale tests) that used /B and
1435 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1436     I have added a new /Z option to pcretest that replaces the length and
1437     offset values with spaces. This is now used to make test 3 independent
1438 ph10 122 of link size. (Test 2 will be tidied up later.)
1439 ph10 123
1440     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1441 ph10 122 segmentation fault instead of returning the appropriate error message.
1442 ph10 134
1443 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1444 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1445     This doesn't seem right; it now treats the CRLF combination as the line
1446     ending, and so does not match in that case. It's only a pattern such as ^$
1447     that would hit this one: something like ^ABC$ would have failed after \r
1448     and then tried again after \r\n.
1450 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1451 ph10 134 in an attempt to make files that differ only in their line terminators
1452     compare equal. This works on Linux.
1453 ph10 142
1454 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1455     as it exited. This is now fixed, thanks to valgrind.
1456 ph10 142
1457 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1458 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1459     was because its rules for how to advance for /g after matching an empty
1460 ph10 143 string at the end of a line did not allow for this case. They now check for
1461     it specially.
1462 ph10 150
1463     20. pcretest is supposed to handle patterns and data of any length, by
1464     extending its buffers when necessary. It was getting this wrong when the
1465 ph10 147 buffer for a data line had to be extended.
1466 ph10 150
1467 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1468 ph10 150 CRLF as a newline sequence.
1469 ph10 152
1470 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1471 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1472     I have nevertheless tidied it up.
1473 ph10 111
1474 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1475 ph10 123
1476 ph10 153 24. Added a man page for pcre-config.
1477 ph10 152
1478 ph10 153
1479 nigel 93 Version 7.0 19-Dec-06
1480     ---------------------
1482     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1483     moving to gcc 4.1.1.
1485     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1486     sys/time.h, which is documented as needed for this function. It doesn't
1487     seem to matter on Linux, but it showed up on some releases of OS X.
1489     3. It seems that there are systems where bytes whose values are greater than
1490     127 match isprint() in the "C" locale. The "C" locale should be the
1491     default when a C program starts up. In most systems, only ASCII printing
1492     characters match isprint(). This difference caused the output from pcretest
1493     to vary, making some of the tests fail. I have changed pcretest so that:
1495     (a) When it is outputting text in the compiled version of a pattern, bytes
1496     other than 32-126 are always shown as hex escapes.
1498     (b) When it is outputting text that is a matched part of a subject string,
1499     it does the same, unless a different locale has been set for the match
1500     (using the /L modifier). In this case, it uses isprint() to decide.
1502     4. Fixed a major bug that caused incorrect computation of the amount of memory
1503     required for a compiled pattern when options that changed within the
1504     pattern affected the logic of the preliminary scan that determines the
1505     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1506     that the computed length was too small. The symptoms of this bug were
1507     either the PCRE error "internal error: code overflow" from pcre_compile(),
1508     or a glibc crash with a message such as "pcretest: free(): invalid next
1509     size (fast)". Examples of patterns that provoked this bug (shown in
1510     pcretest format) are:
1512     /(?-x: )/x
1513     /(?x)(?-x: \s*#\s*)/
1514     /((?i)[\x{c0}])/8
1515     /(?i:[\x{c0}])/8
1517     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1518     is now done differently.
1520     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1521     wrapper classes; (b) implement a new function in the C++ scanner that is
1522     more efficient than the old way of doing things because it avoids levels of
1523     recursion in the regex matching; (c) add a paragraph to the documentation
1524     for the FullMatch() function.
1526     6. The escape sequence \n was being treated as whatever was defined as
1527     "newline". Not only was this contrary to the documentation, which states
1528     that \n is character 10 (hex 0A), but it also went horribly wrong when
1529     "newline" was defined as CRLF. This has been fixed.
1531     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1532     was being set to -1 for the "end of line" case (supposedly a value that no
1533     character can have). Though this value is never used (the check for end of
1534     line is "zero bytes in current character"), it caused compiler complaints.
1535     I've changed it to 0xffffffff.
1537     8. In pcre_version.c, the version string was being built by a sequence of
1538     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1539     string (as it is for production releases) called a macro with an empty
1540     argument. The C standard says the result of this is undefined. The gcc
1541     compiler treats it as an empty string (which was what was wanted) but it is
1542     reported that Visual C gives an error. The source has been hacked around to
1543     avoid this problem.
1545     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1546     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1547     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1548     of them did).
1550     10. Originally, pcretest opened its input and output without "b"; then I was
1551     told that "b" was needed in some environments, so it was added for release
1552     5.0 to both the input and output. (It makes no difference on Unix-like
1553     systems.) Later I was told that it is wrong for the input on Windows. I've
1554     now abstracted the modes into two macros, to make it easier to fiddle with
1555     them, and removed "b" from the input mode under Windows.
1557     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1559     12. Added -help and --help to pcretest as an official way of being reminded
1560     of the options.
1562     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1563     and pcrecpp.cc because they annoy compilers at high warning levels.
1565     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1567     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1568     scripts are not C programs :-) and which was not noticed because it works
1569     on Linux.
1571     16. pcretest is supposed to handle any length of pattern and data line (as one
1572     line or as a continued sequence of lines) by extending its input buffer if
1573     necessary. This feature was broken for very long pattern lines, leading to
1574     a string of junk being passed to pcre_compile() if the pattern was longer
1575     than about 50K.
1577     17. I have done a major re-factoring of the way pcre_compile() computes the
1578     amount of memory needed for a compiled pattern. Previously, there was code
1579     that made a preliminary scan of the pattern in order to do this. That was
1580     OK when PCRE was new, but as the facilities have expanded, it has become
1581     harder and harder to keep it in step with the real compile phase, and there
1582     have been a number of bugs (see for example, 4 above). I have now found a
1583     cunning way of running the real compile function in a "fake" mode that
1584     enables it to compute how much memory it would need, while actually only
1585     ever using a few hundred bytes of working memory and without too many
1586     tests of the mode. This should make future maintenance and development
1587     easier. A side effect of this work is that the limit of 200 on the nesting
1588     depth of parentheses has been removed (though this was never a serious
1589     limitation, I suspect). However, there is a downside: pcre_compile() now
1590     runs more slowly than before (30% or more, depending on the pattern). I
1591     hope this isn't a big issue. There is no effect on runtime performance.
1593     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1594     newline (only possible for the last line of a file) and it was a
1595     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1597     19. Added additional timing features to pcretest. (1) The -tm option now times
1598     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1599     separate command line item, by a number that specifies the number of
1600     repeats to use when timing. The default is 50000; this gives better
1601     precision, but takes uncomfortably long for very large patterns.
1603     20. Extended pcre_study() to be more clever in cases where a branch of a
1604     subpattern has no definite first character. For example, (a*|b*)[cd] would
1605     previously give no result from pcre_study(). Now it recognizes that the
1606     first character must be a, b, c, or d.
1608     21. There was an incorrect error "recursive call could loop indefinitely" if
1609     a subpattern (or the entire pattern) that was being tested for matching an
1610     empty string contained only one non-empty item after a nested subpattern.
1611     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1612     incorrectly, because the \d was being skipped in the check.
1614     22. The pcretest program now has a new pattern option /B and a command line
1615     option -b, which is equivalent to adding /B to every pattern. This causes
1616     it to show the compiled bytecode, without the additional information that
1617     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1618     is the same as /B/I).
1620     23. A new optimization is now able automatically to treat some sequences such
1621     as a*b as a*+b. More specifically, if something simple (such as a character
1622     or a simple class like \d) has an unlimited quantifier, and is followed by
1623     something that cannot possibly match the quantified thing, the quantifier
1624     is automatically "possessified".
1626     24. A recursive reference to a subpattern whose number was greater than 39
1627     went wrong under certain circumstances in UTF-8 mode. This bug could also
1628     have affected the operation of pcre_study().
1630     25. Realized that a little bit of performance could be had by replacing
1631     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1633     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1635     27. Possessive quantifiers such as a++ were previously implemented by turning
1636     them into atomic groups such as ($>a+). Now they have their own opcodes,
1637     which improves performance. This includes the automatically created ones
1638     from 23 above.
1640     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1641     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1642     the first matched character to be a colon. This applied both to named and
1643     numbered groups.
1645     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1647     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1648     building PCRE on Windows easier, so I have included it in the distribution.
1650     31. There is now a check in pcretest against a ridiculously large number being
1651     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1652     loop, the loop is abandoned.
1654     32. Forward references to subpatterns in conditions such as (?(2)...) where
1655     subpattern 2 is defined later cause pcre_compile() to search forwards in
1656     the pattern for the relevant set of parentheses. This search went wrong
1657     when there were unescaped parentheses in a character class, parentheses
1658     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1660     33. "Subroutine" calls and backreferences were previously restricted to
1661     referencing subpatterns earlier in the regex. This restriction has now
1662     been removed.
1664     34. Added a number of extra features that are going to be in Perl 5.10. On the
1665     whole, these are just syntactic alternatives for features that PCRE had
1666     previously implemented using the Python syntax or my own invention. The
1667     other formats are all retained for compatibility.
1669     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1670     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1671     also .NET compatible.
1673     (b) A recursion or subroutine call to a named group can now be defined as
1674     (?&name) as well as (?P>name).
1676     (c) A backreference to a named group can now be defined as \k<name> or
1677     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1678     5.10, are also .NET compatible.
1680     (d) A conditional reference to a named group can now use the syntax
1681     (?(<name>) or (?('name') as well as (?(name).
1683     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1684     groups (named and numbered) that are never evaluated inline, but can be
1685     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1686     is always false. There may be only one alternative in such a group.
1688     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1689     as the simple (?(R). The condition is true only if the most recent
1690     recursion is that of the given number or name. It does not search out
1691     through the entire recursion stack.
1693     (g) The escape \gN or \g{N} has been added, where N is a positive or
1694     negative number, specifying an absolute or relative reference.
1696     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1697     some "unreachable code" warnings.
1699     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1700     things, this adds five new scripts.
1702     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1703     There were also incompatibilities regarding the handling of \Q..\E inside
1704     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1705     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1707     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1708     matches an empty string, and forcibly breaks the loop. There were bugs in
1709     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1710     against aaaa the result was just "a" rather than "aaaa", for example. Two
1711     separate and independent bugs (that affected different cases) have been
1712     fixed.
1714     39. Refactored the code to abolish the use of different opcodes for small
1715     capturing bracket numbers. This is a tidy that I avoided doing when I
1716     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1717     The new approach is not only tidier, it makes it possible to reduce the
1718     memory needed to fix the previous bug (38).
1720     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1721     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1722     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1723     mode.
1725     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1726     report.
1728     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1729     copy construction and assignment in the C++ wrapper.
1731     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1732     couple of bugs that could have given wrong results in the "--newline=crlf"
1733     case.
1735     44. Added a number of casts and did some reorganization of signed/unsigned int
1736     variables following suggestions from Dair Grant. Also renamed the variable
1737     "this" as "item" because it is a C++ keyword.
1739     45. Arranged for dftables to add
1741     #include "pcre_internal.h"
1743     to pcre_chartables.c because without it, gcc 4.x may remove the array
1744     definition from the final binary if PCRE is built into a static library and
1745     dead code stripping is activated.
1747     46. For an unanchored pattern, if a match attempt fails at the start of a
1748     newline sequence, and the newline setting is CRLF or ANY, and the next two
1749     characters are CRLF, advance by two characters instead of one.
1752 nigel 91 Version 6.7 04-Jul-06
1753     ---------------------
1755     1. In order to handle tests when input lines are enormously long, pcretest has
1756     been re-factored so that it automatically extends its buffers when
1757     necessary. The code is crude, but this _is_ just a test program. The
1758     default size has been increased from 32K to 50K.
1760     2. The code in pcre_study() was using the value of the re argument before
1761     testing it for NULL. (Of course, in any sensible call of the function, it
1762     won't be NULL.)
1764     3. The memmove() emulation function in pcre_internal.h, which is used on
1765     systems that lack both memmove() and bcopy() - that is, hardly ever -
1766     was missing a "static" storage class specifier.
1768     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1769     containing an extended class (one that cannot be represented by a bitmap
1770     because it contains high-valued characters or Unicode property items, e.g.
1771     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1772     pattern, but PCRE should not loop if you do not (it no longer does).
1773     [Detail: two cases were found: (a) a repeated subpattern containing an
1774     extended class; (b) a recursive reference to a subpattern that followed a
1775     previous extended class. It wasn't skipping over the extended class
1776     correctly when UTF-8 mode was not set.]
1778     5. A negated single-character class was not being recognized as fixed-length
1779     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1780     compile error "lookbehind assertion is not fixed length".
1782     6. The RunPerlTest auxiliary script was showing an unexpected difference
1783     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1784     write a Perl script that can interpret lines of an input file either as
1785     byte characters or as UTF-8, which is what "perltest" was being required to
1786     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1787     can't do is switch easily at run time between having the "use utf8;" pragma
1788     or not. In the end, I fudged it by using the RunPerlTest script to insert
1789     "use utf8;" explicitly for the UTF-8 tests.
1791     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1792     the end of the subject string, contrary to the documentation and to what
1793     Perl does. This was true of both matching functions. Now it matches only at
1794     the start of the subject and immediately after *internal* newlines.
1796     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1797     a pointer to an int instead of a pointer to an unsigned long int. This
1798     caused problems on 64-bit systems.
1800     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1801     instance of the 'standard' template library not being so standard".
1803     10. There was no check on the number of named subpatterns nor the maximum
1804     length of a subpattern name. The product of these values is used to compute
1805     the size of the memory block for a compiled pattern. By supplying a very
1806     long subpattern name and a large number of named subpatterns, the size
1807     computation could be caused to overflow. This is now prevented by limiting
1808     the length of names to 32 characters, and the number of named subpatterns
1809     to 10,000.
1811     11. Subpatterns that are repeated with specific counts have to be replicated in
1812     the compiled pattern. The size of memory for this was computed from the
1813     length of the subpattern and the repeat count. The latter is limited to
1814     65535, but there was no limit on the former, meaning that integer overflow
1815     could in principle occur. The compiled length of a repeated subpattern is
1816     now limited to 30,000 bytes in order to prevent this.
1818     12. Added the optional facility to have named substrings with the same name.
1820     13. Added the ability to use a named substring as a condition, using the
1821     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1822     are numbers (not recommended). Forward references are permitted.
1824     14. Added forward references in named backreferences (if you see what I mean).
1826     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1827     pattern could run off the end of the subject. For example, the pattern
1828     "(?s)(.{1,5})"8 did this with the subject "ab".
1830     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1831     PCRE_CASELESS was set when matching characters that were quantified with ?
1832     or *.
1834     17. A character class other than a single negated character that had a minimum
1835     but no maximum quantifier - for example [ab]{6,} - was not handled
1836     correctly by pce_dfa_exec(). It would match only one character.
1838     18. A valid (though odd) pattern that looked like a POSIX character
1839     class but used an invalid character after [ (for example [[,abc,]]) caused
1840     pcre_compile() to give the error "Failed: internal error: code overflow" or
1841     in some cases to crash with a glibc free() error. This could even happen if
1842     the pattern terminated after [[ but there just happened to be a sequence of
1843     letters, a binary zero, and a closing ] in the memory that followed.
1845     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1846     over the years. Originally (before any Unicode support), just the bottom 8
1847     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1848     output from "man perlunicode" includes this:
1850     The regular expression compiler produces polymorphic opcodes. That
1851     is, the pattern adapts to the data and automatically switches to
1852     the Unicode character scheme when presented with Unicode data--or
1853     instead uses a traditional byte scheme when presented with byte
1854     data.
1856     Sadly, a wide octal escape does not cause a switch, and in a string with
1857     no other multibyte characters, these octal escapes are treated as before.
1858     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1859     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1860     Unicode string.
1862     I have not perpetrated such confusion in PCRE. Up till now, it took just
1863     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1864     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1865     translate to the appropriate multibyte character.
1867     29. Applied some refactoring to reduce the number of warnings from Microsoft
1868     and Borland compilers. This has included removing the fudge introduced
1869     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1870     a warning about an unused variable.
1872     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1873     characters since release 4.0, because Perl (from release 5.004) does not.
1874     [Or at least, is documented not to: some releases seem to be in conflict
1875     with the documentation.] However, when a pattern was studied with
1876     pcre_study() and all its branches started with \s, PCRE still included VT
1877     as a possible starting character. Of course, this did no harm; it just
1878     caused an unnecessary match attempt.
1880     22. Removed a now-redundant internal flag bit that recorded the fact that case
1881     dependency changed within the pattern. This was once needed for "required
1882     byte" processing, but is no longer used. This recovers a now-scarce options
1883     bit. Also moved the least significant internal flag bit to the most-
1884     significant bit of the word, which was not previously used (hangover from
1885     the days when it was an int rather than a uint) to free up another bit for
1886     the future.
1888     23. Added support for CRLF line endings as well as CR and LF. As well as the
1889     default being selectable at build time, it can now be changed at runtime
1890     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1891     specify that it is scanning data with non-default line endings.
1893     24. Changed the definition of CXXLINK to make it agree with the definition of
1894     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1896     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1897     recursions. This makes a big different to stack usage for some patterns.
1899     26. If a subpattern containing a named recursion or subroutine reference such
1900     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1901     the space required for the compiled pattern went wrong and gave too small a
1902     value. Depending on the environment, this could lead to "Failed: internal
1903     error: code overflow at offset 49" or "glibc detected double free or
1904     corruption" errors.
1906     27. Applied patches from Google (a) to support the new newline modes and (b) to
1907     advance over multibyte UTF-8 characters in GlobalReplace.
1909     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1910     difference for some implementation of PCRE in some Windows version.
1912     29. Added some extra testing facilities to pcretest:
1914     \q<number> in a data line sets the "match limit" value
1915     \Q<number> in a data line sets the "match recursion limt" value
1916     -S <number> sets the stack size, where <number> is in megabytes
1918     The -S option isn't available for Windows.
1921 nigel 89 Version 6.6 06-Feb-06
1922     ---------------------
1924     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1925     in pcreposix.h. I have copied the definition from pcre.h.
1927     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1928     because pcre.h is no longer a built file.
1930     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1931     not normally included in the compiled code.
1934 nigel 87 Version 6.5 01-Feb-06
1935     ---------------------
1937     1. When using the partial match feature with pcre_dfa_exec(), it was not
1938     anchoring the second and subsequent partial matches at the new starting
1939     point. This could lead to incorrect results. For example, with the pattern
1940     /1234/, partially matching against "123" and then "a4" gave a match.
1942     2. Changes to pcregrep:
1944     (a) All non-match returns from pcre_exec() were being treated as failures
1945     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1946     error message is output. Some extra information is given for the
1948     probably the only errors that are likely to be caused by users (by
1949     specifying a regex that has nested indefinite repeats, for instance).
1950     If there are more than 20 of these errors, pcregrep is abandoned.
1952     (b) A binary zero was treated as data while matching, but terminated the
1953     output line if it was written out. This has been fixed: binary zeroes
1954     are now no different to any other data bytes.
1956     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1957     used to set a locale for matching. The --locale=xxxx long option has
1958     been added (no short equivalent) to specify a locale explicitly on the
1959     pcregrep command, overriding the environment variables.
1961     (d) When -B was used with -n, some line numbers in the output were one less
1962     than they should have been.
1964     (e) Added the -o (--only-matching) option.
1966     (f) If -A or -C was used with -c (count only), some lines of context were
1967     accidentally printed for the final match.
1969     (g) Added the -H (--with-filename) option.
1971     (h) The combination of options -rh failed to suppress file names for files
1972     that were found from directory arguments.
1974     (i) Added the -D (--devices) and -d (--directories) options.
1976     (j) Added the -F (--fixed-strings) option.
1978     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1980     (l) Added the --colo(u)r option.
1982     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1983     is not present by default.
1985     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1986     items such as (?R) or (?1), when the recursion could match a number of
1987     alternatives. If it matched one of the alternatives, but subsequently,
1988     outside the recursion, there was a failure, the code tried to back up into
1989     the recursion. However, because of the way PCRE is implemented, this is not
1990     possible, and the result was an incorrect result from the match.
1992     In order to prevent this happening, the specification of recursion has
1993     been changed so that all such subpatterns are automatically treated as
1994     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1996     4. I had overlooked the fact that, in some locales, there are characters for
1997     which isalpha() is true but neither isupper() nor islower() are true. In
1998     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1999     and ordfeminine) are like this. This affected the treatment of \w and \W
2000     when they appeared in character classes, but not when they appeared outside
2001     a character class. The bit map for "word" characters is now created
2002     separately from the results of isalnum() instead of just taking it from the
2003     upper, lower, and digit maps. (Plus the underscore character, of course.)
2005     5. The above bug also affected the handling of POSIX character classes such as
2006     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2007     permanent tables. Instead, the bit maps for such a class were previously
2008     created as the appropriate unions of the upper, lower, and digit bitmaps.
2009     Now they are created by subtraction from the [[:word:]] class, which has
2010     its own bitmap.
2012     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2013     It is created by subtracting the vertical space characters (\x09, \x0a,
2014     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2015     subtraction was done in the overall bitmap for a character class, meaning
2016     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2017     be recognized. This bug has been fixed.
2019     7. Patches from the folks at Google:
2021     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2022     real life, but is still worth protecting against".
2024     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2025     regular expressions".
2027     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2028     have it.
2030     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2031     "configure" and the latter not, in order to fix a problem somebody had
2032     with compiling the Arg class on HP-UX.
2034     (e) Improve the error-handling of the C++ wrapper a little bit.
2036     (f) New tests for checking recursion limiting.
2038     8. The pcre_memmove() function, which is used only if the environment does not
2039     have a standard memmove() function (and is therefore rarely compiled),
2040     contained two bugs: (a) use of int instead of size_t, and (b) it was not
2041     returning a result (though PCRE never actually uses the result).
2043     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2044     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2045     returned instead of calling malloc() with an overflowing number that would
2046     most likely cause subsequent chaos.
2048     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2050     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2051     with this option is matched, the nmatch and pmatch options of regexec() are
2052     ignored.
2054     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2055     provided in case anyone wants to the the POSIX interface with UTF-8
2056     strings.
2058     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2059     C++ linking (needed for some HP-UX environments).
2061     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2062     (unused parameter) and in the pcre_printint() function (omitted "default"
2063     switch label when the default is to do nothing).
2065     15. Added some code to make it possible, when PCRE is compiled as a C++
2066     library, to replace subject pointers for pcre_exec() with a smart pointer
2067     class, thus making it possible to process discontinuous strings.
2069     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2070     much the same function. They were added by different people who were trying
2071     to make PCRE easy to compile on non-Unix systems. It has been suggested
2072     that PCRE_EXPORT be abolished now that there is more automatic apparatus
2073     for compiling on Windows systems. I have therefore replaced it with
2074     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2075     defaults to "extern" for C or "extern C" for C++, which works fine on
2076     Unix-like systems. It is now possible to override the value of PCRE_DATA_
2077     SCOPE with something explicit in config.h. In addition:
2079     (a) pcreposix.h still had just "extern" instead of either of these macros;
2080     I have replaced it with PCRE_DATA_SCOPE.
2082     (b) Functions such as _pcre_xclass(), which are internal to the library,
2083     but external in the C sense, all had PCRE_EXPORT in their definitions.
2084     This is apparently wrong for the Windows case, so I have removed it.
2085     (It makes no difference on Unix-like systems.)
2087     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2088     of recursive calls to match(). This is different to MATCH_LIMIT because
2089     that limits the total number of calls to match(), not all of which increase
2090     the depth of recursion. Limiting the recursion depth limits the amount of
2091     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2092     when PCRE is compiled, and changed at run time. A patch from Google adds
2093     this functionality to the C++ interface.
2095     18. Changes to the handling of Unicode character properties:
2097     (a) Updated the table to Unicode 4.1.0.
2099     (b) Recognize characters that are not in the table as "Cn" (undefined).
2101     (c) I revised the way the table is implemented to a much improved format
2102     which includes recognition of ranges. It now supports the ranges that
2103     are defined in UnicodeData.txt, and it also amalgamates other
2104     characters into ranges. This has reduced the number of entries in the
2105     table from around 16,000 to around 3,000, thus reducing its size
2106     considerably. I realized I did not need to use a tree structure after
2107     all - a binary chop search is just as efficient. Having reduced the
2108     number of entries, I extended their size from 6 bytes to 8 bytes to
2109     allow for more data.
2111     (d) Added support for Unicode script names via properties such as \p{Han}.
2113     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2114     matching that character.
2116     20. When matching a repeated Unicode property with a minimum greater than zero,
2117     (for example \pL{2,}), PCRE could look past the end of the subject if it
2118     reached it while seeking the minimum number of characters. This could
2119     happen only if some of the characters were more than one byte long, because
2120     there is a check for at least the minimum number of bytes.
2122     21. Refactored the implementation of \p and \P so as to be more general, to
2123     allow for more different types of property in future. This has changed the
2124     compiled form incompatibly. Anybody with saved compiled patterns that use
2125     \p or \P will have to recompile them.
2127     22. Added "Any" and "L&" to the supported property types.
2129     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2130     but give a compile time error if the value is greater than 0xff.
2132     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2133     accidentally not being installed or uninstalled.
2135     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2136     made were to insert the current release number. This seemed silly, because
2137     it made things harder for people building PCRE on systems that don't run
2138     "configure". I have turned pcre.h into a distributed file, no longer built
2139     by "configure", with the version identification directly included. There is
2140     no longer a pcre.h.in file.
2142     However, this change necessitated a change to the pcre-config script as
2143     well. It is built from pcre-config.in, and one of the substitutions was the
2144     release number. I have updated configure.ac so that ./configure now finds
2145     the release number by grepping pcre.h.
2147     26. Added the ability to run the tests under valgrind.
2150 nigel 85 Version 6.4 05-Sep-05
2151     ---------------------
2153     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2154     "--" to be printed when multiple files were scanned, even when none of the
2155     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2156     consider it to be a bug, and have restored the previous behaviour.
2158     2. A couple of code tidies to get rid of compiler warnings.
2160     3. The pcretest program used to cheat by referring to symbols in the library
2161     whose names begin with _pcre_. These are internal symbols that are not
2162     really supposed to be visible externally, and in some environments it is
2163     possible to suppress them. The cheating is now confined to including
2164     certain files from the library's source, which is a bit cleaner.
2166     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2167     file's purpose clearer.
2169     5. Reorganized pcre_ucp_findchar().
2172 nigel 83 Version 6.3 15-Aug-05
2173     ---------------------
2175     1. The file libpcre.pc.in did not have general read permission in the tarball.
2177     2. There were some problems when building without C++ support:
2179     (a) If C++ support was not built, "make install" and "make test" still
2180     tried to test it.
2182     (b) There were problems when the value of CXX was explicitly set. Some
2183     changes have been made to try to fix these, and ...
2185     (c) --disable-cpp can now be used to explicitly disable C++ support.
2187     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2188     backslash in a target when C++ was disabled. This confuses some
2189     versions of "make", apparently. Using an intermediate variable solves
2190     this. (Same for CPP_LOBJ.)
2192     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2193     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2194     necessary on certain architectures.
2196     4. Added a setting of -export-symbols-regex to the link command to remove
2197     those symbols that are exported in the C sense, but actually are local
2198     within the library, and not documented. Their names all begin with
2199     "_pcre_". This is not a perfect job, because (a) we have to except some
2200     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2201     available (and never for static libraries). I have made a note to try to
2202     find a way round (a) in the future.
2205 nigel 81 Version 6.2 01-Aug-05
2206     ---------------------
2208     1. There was no test for integer overflow of quantifier values. A construction
2209     such as {1111111111111111} would give undefined results. What is worse, if
2210     a minimum quantifier for a parenthesized subpattern overflowed and became
2211     negative, the calculation of the memory size went wrong. This could have
2212     led to memory overwriting.
2214     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2216     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2217     operating environments where this matters.
2219     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2220     PCRE options from within the C++ wrapper.
2222     5. Named capturing subpatterns were not being correctly counted when a pattern
2223     was compiled. This caused two problems: (a) If there were more than 100
2224     such subpatterns, the calculation of the memory needed for the whole
2225     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2226     back references of the form \12, where the number was greater than 9, were
2227     not recognized as back references, even though there were sufficient
2228     previous subpatterns.
2230     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2231     versions of gcc, e.g. 2.95.4.
2234 nigel 79 Version 6.1 21-Jun-05
2235     ---------------------
2237     1. There was one reference to the variable "posix" in pcretest.c that was not
2238     surrounded by "#if !defined NOPOSIX".
2240     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2241     the cross-check on the old pcre_info() function, for the benefit of the
2242     cut-down version of PCRE that is currently imported into Exim.
2244     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2245     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2246     patterns that start (?i) but I don't think that matters. The use of (?i) is
2247     just an example; this all applies to the other options as well.
2249     4. Since libtool seems to echo the compile commands it is issuing, the output
2250     from "make" can be reduced a bit by putting "@" in front of each libtool
2251     compile command.
2253     5. Patch from the folks at Google for configure.in to be a bit more thorough
2254     in checking for a suitable C++ installation before trying to compile the
2255     C++ stuff. This should fix a reported problem when a compiler was present,
2256     but no suitable headers.
2258     6. The man pages all had just "PCRE" as their title. I have changed them to
2259     be the relevant file name. I have also arranged that these names are
2260     retained in the file doc/pcre.txt, which is a concatenation in text format
2261     of all the man pages except the little individual ones for each function.
2263     7. The NON-UNIX-USE file had not been updated for the different set of source
2264     files that come with release 6. I also added a few comments about the C++
2265     wrapper.
2268 nigel 77 Version 6.0 07-Jun-05
2269     ---------------------
2271     1. Some minor internal re-organization to help with my DFA experiments.
2273     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2274     didn't matter for the library itself when fully configured, but did matter
2275     when compiling without UCP support, or within Exim, where the ucp files are
2276     not imported.
2278     3. Refactoring of the library code to split up the various functions into
2279     different source modules. The addition of the new DFA matching code (see
2280     below) to a single monolithic source would have made it really too
2281     unwieldy, quite apart from causing all the code to be include in a
2282     statically linked application, when only some functions are used. This is
2283     relevant even without the DFA addition now that patterns can be compiled in
2284     one application and matched in another.
2286     The downside of splitting up is that there have to be some external
2287     functions and data tables that are used internally in different modules of
2288     the library but which are not part of the API. These have all had their
2289     names changed to start with "_pcre_" so that they are unlikely to clash
2290     with other external names.
2292     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2293     a different (DFA) algorithm. Although it is slower than the original
2294     function, it does have some advantages for certain types of matching
2295     problem.
2297     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2298     including restarting after a partial match.
2300     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2301     defined when compiling for Windows was sent to me. I have put it into the
2302     code, though I have no means of testing or verifying it.
2304     7. Added the pcre_refcount() auxiliary function.
2306     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2307     match before or at the first newline in the subject string. In pcretest,
2308     the /f option on a pattern can be used to set this.
2310     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2311     would behave wrongly. This has been present in PCRE since release 4.0.
2313     10. A number of changes to the pcregrep command:
2315     (a) Refactored how -x works; insert ^(...)$ instead of setting
2316     PCRE_ANCHORED and checking the length, in preparation for adding
2317     something similar for -w.
2319     (b) Added the -w (match as a word) option.
2321     (c) Refactored the way lines are read and buffered so as to have more
2322     than one at a time available.
2324     (d) Implemented a pcregrep test script.
2326     (e) Added the -M (multiline match) option. This allows patterns to match
2327     over several lines of the subject. The buffering ensures that at least
2328     8K, or the rest of the document (whichever is the shorter) is available
2329     for matching (and similarly the previous 8K for lookbehind assertions).
2331     (f) Changed the --help output so that it now says
2333     -w, --word-regex(p)
2335     instead of two lines, one with "regex" and the other with "regexp"
2336     because that confused at least one person since the short forms are the
2337     same. (This required a bit of code, as the output is generated
2338     automatically from a table. It wasn't just a text change.)
2340     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2341     option but starts with a hyphen. Could be a pattern or a path name
2342     starting with a hyphen, for instance.
2344     (h) "-" can be given as a file name to represent stdin.
2346     (i) When file names are being printed, "(standard input)" is used for
2347     the standard input, for compatibility with GNU grep. Previously
2348     "<stdin>" was used.
2350     (j) The option --label=xxx can be used to supply a name to be used for
2351     stdin when file names are being printed. There is no short form.
2353     (k) Re-factored the options decoding logic because we are going to add
2354     two more options that take data. Such options can now be given in four
2355     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2357     (l) Added the -A, -B, and -C options for requesting that lines of context
2358     around matches be printed.
2360     (m) Added the -L option to print the names of files that do not contain
2361     any matching lines, that is, the complement of -l.
2363     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2364     continue to scan other files.
2366     (o) The -s option was incorrectly implemented. For compatibility with other
2367     greps, it now suppresses the error message for a non-existent or non-
2368     accessible file (but not the return code). There is a new option called
2369     -q that suppresses the output of matching lines, which was what -s was
2370     previously doing.
2372     (p) Added --include and --exclude options to specify files for inclusion
2373     and exclusion when recursing.
2375     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2376     Hopefully, it now does.
2378     12. Missing cast in pcre_study().
2380     13. Added an "uninstall" target to the makefile.
2382     14. Replaced "extern" in the function prototypes in Makefile.in with
2383     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2384     world, but is set differently for Windows.
2386     15. Added a second compiling function called pcre_compile2(). The only
2387     difference is that it has an extra argument, which is a pointer to an
2388     integer error code. When there is a compile-time failure, this is set
2389     non-zero, in addition to the error test pointer being set to point to an
2390     error message. The new argument may be NULL if no error number is required
2391     (but then you may as well call pcre_compile(), which is now just a
2392     wrapper). This facility is provided because some applications need a
2393     numeric error indication, but it has also enabled me to tidy up the way
2394     compile-time errors are handled in the POSIX wrapper.
2396     16. Added VPATH=.libs to the makefile; this should help when building with one
2397     prefix path and installing with another. (Or so I'm told by someone who
2398     knows more about this stuff than I do.)
2400     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2401     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2402     match everything, including newlines. This is not POSIX-compatible, but
2403     somebody wanted the feature. From pcretest it can be activated by using
2404     both the P and the s flags.
2406     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2408     19. libpcre.pc was being incorrectly installed as executable.
2410     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2411     it now also looks for '\r' so that it will work unmodified on Windows.
2413     21. Added Google's contributed C++ wrapper to the distribution.
2415     22. Added some untidy missing memory free() calls in pcretest, to keep
2416     Electric Fence happy when testing.
2420 nigel 75 Version 5.0 13-Sep-04
2421     ---------------------
2423     1. Internal change: literal characters are no longer packed up into items
2424     containing multiple characters in a single byte-string. Each character
2425     is now matched using a separate opcode. However, there may be more than one
2426     byte in the character in UTF-8 mode.
2428     2. The pcre_callout_block structure has two new fields: pattern_position and
2429     next_item_length. These contain the offset in the pattern to the next match
2430     item, and its length, respectively.
2432     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2433     insertion of callouts before each pattern item. Added the /C option to
2434     pcretest to make use of this.
2436     4. On the advice of a Windows user, the lines
2438     #if defined(_WIN32) || defined(WIN32)
2439     _setmode( _fileno( stdout ), 0x8000 );
2440     #endif /* defined(_WIN32) || defined(WIN32) */
2442     have been added to the source of pcretest. This apparently does useful
2443     magic in relation to line terminators.
2445     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2446     for the benefit of those environments where the "b" makes a difference.
2448     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2449     to know about it. I have put a hack into configure.in that adds in code
2450     to set GCC=yes if CC=icc. This seems to end up at a point in the
2451     generated configure script that is early enough to affect the setting of
2452     compiler options, which is what is needed, but I have no means of testing
2453     whether it really works. (The user who reported this had patched the
2454     generated configure script, which of course I cannot do.)
2456     LATER: After change 22 below (new libtool files), the configure script
2457     seems to know about icc (and also ecc). Therefore, I have commented out
2458     this hack in configure.in.
2460     7. Added support for pkg-config (2 patches were sent in).
2462     8. Negated POSIX character classes that used a combination of internal tables
2463     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2464     [[:^ascii]]. Typically, they would match almost any characters. The other
2465     POSIX classes were not broken in this way.
2467     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2468     to find the match, as PCRE was deluded into thinking that the match had to
2469     start at the start point or following a newline. The same bug applied to
2470     patterns with negative forward assertions or any backward assertions
2471     preceding ".*" at the start, unless the pattern required a fixed first
2472     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2474     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2475     starting at the last subject character, bytes beyond the end of the subject
2476     string were read.
2478     11. Renamed the variable "class" as "classbits" to make life easier for C++
2479     users. (Previously there was a macro definition, but it apparently wasn't
2480     enough.)
2482     12. Added the new field "tables" to the extra data so that tables can be passed
2483     in at exec time, or the internal tables can be re-selected. This allows
2484     a compiled regex to be saved and re-used at a later time by a different
2485     program that might have everything at different addresses.
2487     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2488     -R library as well as a -L library.
2490     14. The debugging options of pcretest (-d on the command line or D on a
2491     pattern) showed incorrect output for anything following an extended class
2492     that contained multibyte characters and which was followed by a quantifier.
2494     15. Added optional support for general category Unicode character properties
2495     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2496     support. It adds about 90K to the size of the library. The meanings of the
2497     inbuilt class escapes such as \d and \s have NOT been changed.
2499     16. Updated pcredemo.c to include calls to free() to release the memory for the
2500     compiled pattern.
2502     17. The generated file chartables.c was being created in the source directory
2503     instead of in the building directory. This caused the build to fail if the
2504     source directory was different from the building directory, and was
2505     read-only.
2507     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2508     file. No doubt somebody will tell me if they don't make sense... Also added
2509     Dan Mooney's comments about building on OpenVMS.
2511     19. Added support for partial matching via the PCRE_PARTIAL option for
2512     pcre_exec() and the \P data escape in pcretest.
2514     20. Extended pcretest with 3 new pattern features:
2516     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2517     write the compiled pattern to the file whose name is "rest-of-line".
2518     This is a straight binary dump of the data, with the saved pointer to
2519     the character tables forced to be NULL. The study data, if any, is
2520     written too. After writing, pcretest reads a new pattern.
2522     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2523     compiled pattern from the given file. There must not be any
2524     occurrences of "<" in the file name (pretty unlikely); if there are,
2525     pcretest will instead treat the initial "<" as a pattern delimiter.
2526     After reading in the pattern, pcretest goes on to read data lines as
2527     usual.
2529     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2530     and 16-bit fields in a compiled pattern, to simulate a pattern that
2531     was compiled on a host of opposite endianness.
2533     21. The pcre-exec() function can now cope with patterns that were compiled on
2534     hosts of opposite endianness, with this restriction:
2536     As for any compiled expression that is saved and used later, the tables
2537     pointer field cannot be preserved; the extra_data field in the arguments
2538     to pcre_exec() should be used to pass in a tables address if a value
2539     other than the default internal tables were used at compile time.
2541     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2542     now diagnosed as an error. Previously, most of the time, a negative number
2543     would have been treated as zero, but if in addition "ovector" was passed as
2544     NULL, a crash could occur.
2546     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2547     new versions from the libtool 1.5 distribution (the last one is a copy of
2548     a file called libtool.m4). This seems to have fixed the need to patch
2549     "configure" to support Darwin 1.3 (which I used to do). However, I still
2550     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2551     workstation).
2553     24. Changed the PCRE licence to be the more standard "BSD" licence.
2556 nigel 73 Version 4.5 01-Dec-03
2557     ---------------------
2559     1. There has been some re-arrangement of the code for the match() function so
2560     that it can be compiled in a version that does not call itself recursively.
2561     Instead, it keeps those local variables that need separate instances for
2562     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2563     needs to "recurse". Keeping track of where control must go is done by means
2564     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2565     hide most of the details from the main code, and operates only if
2566     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2567     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2568     operating.
2570     To make it easier for callers to provide specially tailored get/free
2571     functions for this usage, two new functions, pcre_stack_malloc, and
2572     pcre_stack_free, are used. They are always called in strict stacking order,
2573     and the size of block requested is always the same.
2575     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2576     PCRE has been compiled to use the stack or the heap for recursion. The
2577     -C option of pcretest uses this to show which version is compiled.
2579     A new data escape \S, is added to pcretest; it causes the amounts of store
2580     obtained and freed by both kinds of malloc/free at match time to be added
2581     to the output.
2583     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2584     what's available on my current Linux desktop machine.
2586     3. When matching a UTF-8 string, the test for a valid string at the start has
2587     been extended. If start_offset is not zero, PCRE now checks that it points
2588     to a byte that is the start of a UTF-8 character. If not, it returns
2589     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2590     this is necessary because there may be backward assertions in the pattern.
2591     When matching the same subject several times, it may save resources to use
2592     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2594     4. The code for checking the validity of UTF-8 strings has been tightened so
2595     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2596     containing "overlong sequences".
2598     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2599     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2600     should have been "&", but it just so happened that all the cases this let
2601     through by mistake were picked up later in the function.
2603     6. I had used a variable called "isblank" - this is a C99 function, causing
2604     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2606     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2607     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2608     so the version is shown; (c) stop "make test" echoing "./RunTest".
2610     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2612     9. The prototype for memmove() for systems that don't have it was using
2613     size_t, but the inclusion of the header that defines size_t was later. I've
2614     moved the #includes for the C headers earlier to avoid this.
2616     10. Added some adjustments to the code to make it easier to compiler on certain
2617     special systems:
2619     (a) Some "const" qualifiers were missing.
2620     (b) Added the macro EXPORT before all exported functions; by default this
2621     is defined to be empty.
2622     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2623     that it reads its output file name as an argument instead of writing
2624     to the standard output and assuming this can be redirected.
2626     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2627     class containing characters with values greater than 255, PCRE compilation
2628     went into a loop.
2630     12. A recursive reference to a subpattern that was within another subpattern
2631     that had a minimum quantifier of zero caused PCRE to crash. For example,
2632     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2633     recursion. If the recursively-called subpattern itself had a zero repeat,
2634     that was OK.
2636     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2637     buffer into which it was copied (for escape processing) was still set at
2638     1024, so long lines caused crashes.
2640     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2641     "internal error: code overflow...". This applied to any character class
2642     that was followed by a possessive quantifier.
2644     15. Modified the Makefile to add libpcre.la as a prerequisite for
2645     libpcreposix.la because I was told this is needed for a parallel build to
2646     work.
2648     16. If a pattern that contained .* following optional items at the start was
2649     studied, the wrong optimizing data was generated, leading to matching
2650     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2651     matching string must start with a or b or c. The correct conclusion for
2652     this pattern is that a match can start with any character.
2655 nigel 71 Version 4.4 13-Aug-03
2656     ---------------------
2658     1. In UTF-8 mode, a character class containing characters with values between
2659     127 and 255 was not handled correctly if the compiled pattern was studied.
2660     In fixing this, I have also improved the studying algorithm for such
2661     classes (slightly).
2663     2. Three internal functions had redundant arguments passed to them. Removal
2664     might give a very teeny performance improvement.
2666     3. Documentation bug: the value of the capture_top field in a callout is *one
2667     more than* the number of the hightest numbered captured substring.
2669     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2670     in incorrectly linking with a previously installed version. They now link
2671     explicitly with libpcre.la.
2673     5. configure.in no longer needs to recognize Cygwin specially.
2675     6. A problem in pcre.in for Windows platforms is fixed.
2677     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2678     pcretest, it used to include the size of the study block as part of its
2679     output. Unfortunately, the structure contains a field that has a different
2680     size on different hardware architectures. This meant that the tests that
2681     showed this size failed. As the block is currently always of a fixed size,
2682     this information isn't actually particularly useful in pcretest output, so
2683     I have just removed it.
2685     8. Three pre-processor statements accidentally did not start in column 1.
2686     Sadly, there are *still* compilers around that complain, even though
2687     standard C has not required this for well over a decade. Sigh.
2689     9. In pcretest, the code for checking callouts passed small integers in the
2690     callout_data field, which is a void * field. However, some picky compilers
2691     complained about the casts involved for this on 64-bit systems. Now
2692     pcretest passes the address of the small integer instead, which should get
2693     rid of the warnings.
2695     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2696     both compile and run time, and gives an error if an invalid UTF-8 sequence
2697     is found. There is a option for disabling this check in cases where the
2698     string is known to be correct and/or the maximum performance is wanted.
2700     11. In response to a bug report, I changed one line in Makefile.in from
2702     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2703     to
2704     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2706     to look similar to other lines, but I have no way of telling whether this
2707     is the right thing to do, as I do not use Windows. No doubt I'll get told
2708     if it's wrong...
2711 nigel 69 Version 4.3 21-May-03
2712     ---------------------
2714     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2715     Makefile.
2717     2. Some refactoring to improve the quality of the code:
2719     (i) The utf8_table... variables are now declared "const".
2721     (ii) The code for \cx, which used the "case flipping" table to upper case
2722     lower case letters, now just substracts 32. This is ASCII-specific,
2723     but the whole concept of \cx is ASCII-specific, so it seems
2724     reasonable.
2726     (iii) PCRE was using its character types table to recognize decimal and
2727     hexadecimal digits in the pattern. This is silly, because it handles
2728     only 0-9, a-f, and A-F, but the character types table is locale-
2729     specific, which means strange things might happen. A private
2730     table is now used for this - though it costs 256 bytes, a table is
2731     much faster than multiple explicit tests. Of course, the standard
2732     character types table is still used for matching digits in subject
2733     strings against \d.
2735     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2736     ending in _t are). So I've renamed it as ESC_tee.
2738     3. The first argument for regexec() in the POSIX wrapper should have been
2739     defined as "const".
2741     4. Changed pcretest to use malloc() for its buffers so that they can be
2742     Electric Fenced for debugging.
2744     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2745     to read one or more bytes before the start of the subject string. Often this
2746     had no effect on PCRE's behaviour, but in some circumstances it could
2747     provoke a segmentation fault.
2749     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2750     to try to read one or more bytes before the start of the subject string.
2752     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2753     UTF-8 support could misbehave in various ways if the subject string
2754     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2755     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2756     back over UTF-8 characters.)
2759 nigel 67 Version 4.2 14-Apr-03
2760     ---------------------
2762     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2764     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2765     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2766     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2767     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2768     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2769     and BUILD_EXEEXT
2770     Note: automatic setting of the BUILD variables is not yet working
2771     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2772     compile-time but not at link-time
2773     [LINK]: use for linking executables only
2774     make different versions for Windows and non-Windows
2775     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2776     libraries
2777     [LINK_FOR_BUILD]: new variable
2778     [OBJEXT]: use throughout
2779     [EXEEXT]: use throughout
2780     <winshared>: new target
2781     <wininstall>: new target
2782     <dftables.o>: use native compiler
2783     <dftables>: use native linker
2784     <install>: handle Windows platform correctly
2785     <clean>: ditto
2786     <check>: ditto
2787     copy DLL to top builddir before testing
2789     As part of these changes, -no-undefined was removed again. This was reported
2790     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2791     in any case.
2793     3. Some tidies to get rid of compiler warnings:
2795     . In the match_data structure, match_limit was an unsigned long int, whereas
2796     match_call_count was an int. I've made them both unsigned long ints.
2798     . In pcretest the fact that a const uschar * doesn't automatically cast to
2799     a void * provoked a warning.
2801     . Turning on some more compiler warnings threw up some "shadow" variables
2802     and a few more missing casts.
2804     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2805     option, a class that contained a single character with a value between 128
2806     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2808     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2809     option, a class that contained several characters, but with at least one
2810     whose value was between 128 and 255 caused PCRE to crash.
2813 nigel 65 Version 4.1 12-Mar-03
2814     ---------------------
2815 nigel 63
2816 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2817     needed, and a string in dftables.c that was longer than standard compilers are
2818     required to support.
2820     2. Compiling with Sun's compiler found a few more places where the code could
2821     be tidied up in order to avoid warnings.
2823     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2824     first of these names is deprecated in the latest Autoconf in favour of the name
2825     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2826     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2827     analogy I have changed it to CFLAGS_FOR_BUILD.
2829     4. Added -no-undefined to the linking command in the Makefile, because this is
2830     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2831     linking step for the pcreposix library.
2833     5. PCRE was failing to diagnose the case of two named groups with the same
2834     name.
2836     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2837     literal character that is needed in the subject for a match, and scans along to
2838     ensure that it is present before embarking on the full matching process. This
2839     saves time in cases of nested unlimited repeats that are never going to match.
2840     Problem: the scan can take a lot of time if the subject is very long (e.g.
2841     megabytes), thus penalizing straightforward matches. It is now done only if the
2842     amount of subject to be scanned is less than 1000 bytes.
2844     7. A lesser problem with the same optimization is that it was recording the
2845     first character of an anchored pattern as "needed", thus provoking a search
2846     right along the subject, even when the first match of the pattern was going to
2847     fail. The "needed" character is now not set for anchored patterns, unless it
2848     follows something in the pattern that is of non-fixed length. Thus, it still
2849     fulfils its original purpose of finding quick non-matches in cases of nested
2850     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2853     Version 4.0 17-Feb-03
2854     ---------------------
2856 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2857     extended to the end of string, PCRE compiled incorrect data. This could lead to
2858     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2860     2. Moved to autoconf 2.53 and libtool 1.4.2.
2862     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2863     the special perltest8 script is no longer needed - all the tests can be run
2864     from a single perltest script.
2866     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2867     by \s. It has now been removed in PCRE. This means it isn't recognized as
2868     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2869     class [:space:] *does* include VT, thereby creating a mess.
2871     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2872     space and tab.
2874     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2875     its new features into the main test script, reducing the number of scripts.
2877     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2878     were backward compatible, and made the (?i) apply to the whole pattern, as if
2879     /i were given. Now it behaves more logically, and applies the option setting
2880     only to what follows. PCRE has been changed to follow suit. However, if it
2881     finds options settings right at the start of the pattern, it extracts them into
2882     the global options, as before. Thus, they show up in the info data.
2884     8. Added support for the \Q...\E escape sequence. Characters in between are
2885     treated as literals. This is slightly different from Perl in that $ and @ are
2886     also handled as literals inside the quotes. In Perl, they will cause variable
2887     interpolation. Note the following examples:
2889     Pattern PCRE matches Perl matches
2891     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2892     \Qabc\$xyz\E abc\$xyz abc\$xyz
2893     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2895     For compatibility with Perl, \Q...\E sequences are recognized inside character
2896     classes as well as outside them.
2898     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2899     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2900     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2901     signed/unsigned warnings.
2903     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2904     option for pcretest, so I've replaced it by a simple function that does just
2905     that job.
2907     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2908     "pcregrep -".
2910     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2911     Java package. This provides some syntactic sugar for simple cases of what my
2912     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2913     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2914     item, you can use this simplified notation. Note that only makes sense with
2915     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2916     greediness, whatever the setting of the PCRE_UNGREEDY option.
2918     13. A change of greediness default within a pattern was not taking effect at
2919     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2920     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2921     was abstracted outside.
2923     14. PCRE now supports the \G assertion. It is true when the current matching
2924     position is at the start point of the match. This differs from \A when the
2925     starting offset is non-zero. Used with the /g option of pcretest (or similar
2926     code), it works in the same way as it does for Perl's /g option. If all
2927     alternatives of a regex begin with \G, the expression is anchored to the start
2928     match position, and the "anchored" flag is set in the compiled expression.
2930     15. Some bugs concerning the handling of certain option changes within patterns
2931     have been fixed. These applied to options other than (?ims). For example,
2932     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2933     been the other way round. Some of this was related to change 7 above.
2935     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2936     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2937     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2938     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2940     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2941     mode. Unlike ".", it always matches newline, whatever the setting of
2942     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2943     assertions. Perl allows it, but it doesn't (in general) work because it can't
2944     calculate the length of the lookbehind. At least, that's the case for Perl
2945     5.8.0 - I've been told they are going to document that it doesn't work in
2946     future.
2948     18. Added an error diagnosis for escapes that PCRE does not support: these are
2949     \L, \l, \N, \P, \p, \U, \u, and \X.
2951     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2952     reading past the end of the pattern in cases such as /[abcd/.
2954     20. PCRE was getting more memory than necessary for patterns with classes that
2955     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2957     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2958     compiling PCRE for use with Virtual Pascal.
2960     22. Small fix to the Makefile to make it work properly if the build is done
2961     outside the source tree.
2963     23. Added a new extension: a condition to go with recursion. If a conditional
2964     subpattern starts with (?(R) the "true" branch is used if recursion has
2965     happened, whereas the "false" branch is used only at the top level.
2967     24. When there was a very long string of literal characters (over 255 bytes
2968     without UTF support, over 250 bytes with UTF support), the computation of how
2969     much memory was required could be incorrect, leading to segfaults or other
2970     strange effects.
2972     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2973     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2974     there was a subsequent back reference to those brackets. This meant that, for
2975     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2976     possible to check for precisely this case. All we can do is abandon the
2977     optimization if .* occurs inside capturing brackets when there are any back
2978     references whatsoever. (See below for a better fix that came later.)
2980     26. The handling of the optimization for finding the first character of a
2981     non-anchored pattern, and for finding a character that is required later in the
2982     match were failing in some cases. This didn't break the matching; it just
2983     failed to optimize when it could. The way this is done has been re-implemented.
2985     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2987     28. Added a new feature that provides some of the functionality that Perl
2988     provides with (?{...}). The facility is termed a "callout". The way it is done
2989     in PCRE is for the caller to provide an optional function, by setting
2990     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2991     global variable. By default it is unset, which disables all calling out. To get
2992     the function called, the regex must include (?C) at appropriate points. This
2993     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2994     This provides a means of identifying different callout points. When PCRE
2995     reaches such a point in the regex, if pcre_callout has been set, the external
2996     function is called. It is provided with data in a structure called
2997     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2998     matching continues; if it returns a non-zero value, the match at the current
2999     point fails. However, backtracking will occur if possible. [This was changed
3000     later and other features added - see item 49 below.]
3002     29. pcretest is upgraded to test the callout functionality. It provides a
3003     callout function that displays information. By default, it shows the start of
3004     the match and the current position in the text. There are some new data escapes
3005     to vary what happens:
3007     \C+ in addition, show current contents of captured substrings
3008     \C- do not supply a callout function
3009     \C!n return 1 when callout number n is reached
3010     \C!n!m return 1 when callout number n is reached for the mth time
3012     30. If pcregrep was called with the -l option and just a single file name, it
3013     output "<stdin>" if a match was found, instead of the file name.
3015     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3016     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3017     pcre_exec(). This saves a malloc/free per call. The default value of
3018     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3019     when configuring.
3021     32. The default maximum size of a compiled pattern is 64K. There have been a
3022     few cases of people hitting this limit. The code now uses macros to handle the
3023     storing of links as offsets within the compiled pattern. It defaults to 2-byte
3024     links, but this can be changed to 3 or 4 bytes by --with-link-size when
3025     configuring. Tests 2 and 5 work only with 2-byte links because they output
3026     debugging information about compiled patterns.
3028     33. Internal code re-arrangements:
3030     (a) Moved the debugging function for printing out a compiled regex into
3031     its own source file (printint.c) and used #include to pull it into
3032     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3033     separate copies.
3035     (b) Defined the list of op-code names for debugging as a macro in
3036     internal.h so that it is next to the definition of the opcodes.
3038     (c) Defined a table of op-code lengths for simpler skipping along compiled
3039     code. This is again a macro in internal.h so that it is next to the
3040     definition of the opcodes.
3042     34. Added support for recursive calls to individual subpatterns, along the
3043     lines of Robin Houston's patch (but implemented somewhat differently).
3045     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3046     allow it to read and process whole directories in Win32. This code was
3047     contributed by Lionel Fourquaux; it has not been tested by me.
3049     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3050     used to name a group. Names consist of alphanumerics and underscores, and must
3051     be unique. Back references use the syntax (?P=name) and recursive calls use
3052     (?P>name) which is a PCRE extension to the Python extension. Groups still have
3053     numbers. The function pcre_fullinfo() can be used after compilation to extract
3054     a name/number map. There are three relevant calls:
3056     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3057     PCRE_INFO_NAMECOUNT yields the number of entries
3058     PCRE_INFO_NAMETABLE yields a pointer to the map.
3060     The map is a vector of fixed-size entries. The size of each entry depends on
3061     the length of the longest name used. The first two bytes of each entry are the
3062     group number, most significant byte first. There follows the corresponding
3063     name, zero terminated. The names are in alphabetical order.
3065     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3066     case instead of 255. Making it the same both with and without UTF-8 support
3067     means that the same test output works with both.
3069     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3070     calling malloc() with a zero argument.
3072     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3073     optimization. I've improved things by keeping a bitmap of backreferences with
3074     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3075     fact referenced, the optimization can be applied. It is unlikely that a
3076     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3077     the match to follow \n) will appear inside brackets with a number greater than
3078     31, but if it does, any back reference > 31 suppresses the optimization.
3080     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3081     of disabling numbered capturing parentheses. Any opening parenthesis that is
3082     not followed by ? behaves as if it were followed by ?: but named parentheses
3083     can still be used for capturing (and they will acquire numbers in the usual
3084     way).
3086     41. Redesigned the return codes from the match() function into yes/no/error so
3087     that errors can be passed back from deep inside the nested calls. A malloc
3088     failure while inside a recursive subpattern call now causes the
3089     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3091     42. It is now possible to set a limit on the number of times the match()
3092     function is called in a call to pcre_exec(). This facility makes it possible to
3093     limit the amount of recursion and backtracking, though not in a directly
3094     obvious way, because the match() function is used in a number of different
3095     circumstances. The count starts from zero for each position in the subject
3096     string (for non-anchored patterns). The default limit is, for compatibility, a
3097     large number, namely 10 000 000. You can change this in two ways:
3099     (a) When configuring PCRE before making, you can use --with-match-limit=n
3100     to set a default value for the compiled library.
3102     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3103     a different value is set. See 45 below.
3105     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3107     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3108     of things that can be changed at compile time. The first argument specifies
3109     what is wanted and the second points to where the information is to be placed.
3110     The current list of available information is:
3114     The output is an integer that is set to one if UTF-8 support is available;
3115     otherwise it is set to zero.
3119     The output is an integer that it set to the value of the code that is used for
3120     newline. It is either LF (10) or CR (13).
3124     The output is an integer that contains the number of bytes used for internal
3125     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3129     The output is an integer that contains the threshold above which the POSIX
3130     interface uses malloc() for output vectors. See item 31 above.
3134     The output is an unsigned integer that contains the default limit of the number
3135     of match() calls in a pcre_exec() execution. See 42 above.
3137     44. pcretest has been upgraded by the addition of the -C option. This causes it
3138     to extract all the available output from the new pcre_config() function, and to
3139     output it. The program then exits immediately.
3141     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3142     order to support additional features. One way would have been to define
3143     pcre_exec2() (for example) with extra arguments, but this would not have been
3144     extensible, and would also have required all calls to the original function to
3145     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3146     is used for passing in "extra" data from pcre_study().
3148     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3149     contains the following fields:
3151     flags a bitmap indicating which of the following fields are set
3152     study_data opaque data from pcre_study()
3153     match_limit a way of specifying a limit on match() calls for a specific
3154     call to pcre_exec()
3155     callout_data data for callouts (see 49 below)
3157     The flag bits are also defined in pcre.h, and are
3163     The pcre_study() function now returns one of these new pcre_extra blocks, with
3164     the actual study data pointed to by the study_data field, and the
3165     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3166     before. That is, this change is entirely upwards-compatible and requires no
3167     change to existing code.
3169     If you want to pass in additional data to pcre_exec(), you can either place it
3170     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3171     block.
3173     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3174     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3175     times with different match limits, until it finds the minimum value needed for
3176     pcre_exec() to complete. The value is then output. This can be instructive; for
3177     most simple matches the number is quite small, but for pathological cases it
3178     gets very large very quickly.
3180     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3181     returns the size of the data block pointed to by the study_data field in a
3182     pcre_extra block, that is, the value that was passed as the argument to
3183     pcre_malloc() when PCRE was getting memory in which to place the information
3184     created by pcre_study(). The fourth argument should point to a size_t variable.
3185     pcretest has been extended so that this information is shown after a successful
3186     pcre_study() call when information about the compiled regex is being displayed.
3188     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3189     because what follows is always an absolute path. (Later: it turns out that this
3190     is more than cosmetic for MinGW, because it doesn't like empty path
3191     components.)
3193     49. Some changes have been made to the callout feature (see 28 above):
3195     (i) A callout function now has three choices for what it returns:
3197     0 => success, carry on matching
3198     > 0 => failure at this point, but backtrack if possible
3199     < 0 => serious error, return this value from pcre_exec()
3201     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3202     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3203     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3204     use by callout functions. It will never be used by PCRE itself.
3206     (ii) The pcre_extra structure (see 45 above) has a void * field called
3207     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3208     pcre_callout_block structure has a field of the same name. The contents of
3209     the field passed in the pcre_extra structure are passed to the callout
3210     function in the corresponding field in the callout block. This makes it
3211     easier to use the same callout-containing regex from multiple threads. For
3212     testing, the pcretest program has a new data escape
3214     \C*n pass the number n (may be negative) as callout_data
3216     If the callout function in pcretest receives a non-zero value as
3217     callout_data, it returns that value.
3219     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3220     there were some redundant $(CFLAGS) in commands that are now specified as
3221     $(LINK), which already includes $(CFLAGS).
3223     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3224     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3225     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3226     one-byte characters throughout. Note that case-insensitive matching applies
3227     only to characters whose values are less than 256. PCRE doesn't support the
3228     notion of cases for higher-valued characters.
3230     (i) A character class whose characters are all within 0-255 is handled as
3231     a bit map, and the map is inverted for negative classes. Previously, a
3232     character > 255 always failed to match such a class; however it should
3233     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3235     (ii) A negated character class with a single character < 255 is coded as
3236     "not this character" (OP_NOT). This wasn't working properly when the test
3237     character was multibyte, either singly or repeated.
3239     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3240     mode, for example: \x{100}{2,3}.
3242     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3243     singly or repeated) now correctly test multibyte characters. However,
3244     PCRE doesn't recognize any characters with values greater than 255 as
3245     digits, spaces, or word characters. Such characters always match \D, \S,
3246     and \W, and never match \d, \s, or \w.
3248     (v) Classes may now contain characters and character ranges with values
3249     greater than 255. For example: [ab\x{100}-\x{400}].
3251     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3252     PCRE in UTF-8 mode.
3254     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3255     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3256     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3257     value.)
3259     53. The single man page has become too large. I have therefore split it up into
3260     a number of separate man pages. These also give rise to individual HTML pages;
3261     these are now put in a separate directory, and there is an index.html page that
3262     lists them all. Some hyperlinking between the pages has been installed.
3264     54. Added convenience functions for handling named capturing parentheses.
3266     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3267     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3268     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3269     are faulted.
3271     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3272     calling configure. These values are used when compiling the dftables.c program
3273     which is run to generate the source of the default character tables. They
3274     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3275     you will need to set these values.
3277     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3280     Version 3.9 02-Jan-02
3281 nigel 61 ---------------------
3283     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3285     2. If --disable-static was given, the building process failed when trying to
3286     build pcretest and pcregrep. (For some reason it was using libtool to compile
3287     them, which is not right, as they aren't part of the library.)
3290 nigel 59 Version 3.8 18-Dec-01
3291     ---------------------
3293     1. The experimental UTF-8 code was completely screwed up. It was packing the
3294     bytes in the wrong order. How dumb can you get?
3297 nigel 57 Version 3.7 29-Oct-01
3298     ---------------------
3300     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3301     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3302     this didn't happen under Solaris 8, where I normally test things.
3304 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3305     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3306     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3307     this fix an hour or so after the initial 3.7 release.)
3308 nigel 57
3309 nigel 59
3310 nigel 55 Version 3.6 23-Oct-01
3311     ---------------------
3313     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3314     offsets passed as NULL with zero offset count.
3316     2. The config.guess and config.sub files had not been updated when I moved to
3317     the latest autoconf.
3320 nigel 53 Version 3.5 15-Aug-01
3321     ---------------------
3322 nigel 5
3323 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3324     had been forgotten.
3326     2. By using declared but undefined structures, we can avoid using "void"
3327     definitions in pcre.h while keeping the internal definitions of the structures
3328     private.
3330     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3331     user point of view, this means that both static and shared libraries are built
3332     by default, but this can be individually controlled. More of the work of
3333     handling this static/shared cases is now inside libtool instead of PCRE's make
3334     file.
3336     4. The pcretest utility is now installed along with pcregrep because it is
3337     useful for users (to test regexs) and by doing this, it automatically gets
3338     relinked by libtool. The documentation has been turned into a man page, so
3339     there are now .1, .txt, and .html versions in /doc.
3341     5. Upgrades to pcregrep:
3342     (i) Added long-form option names like gnu grep.
3343     (ii) Added --help to list all options with an explanatory phrase.
3344     (iii) Added -r, --recursive to recurse into sub-directories.
3345     (iv) Added -f, --file to read patterns from a file.
3347     6. pcre_exec() was referring to its "code" argument before testing that
3348     argument for NULL (and giving an error if it was NULL).
3350     7. Upgraded Makefile.in to allow for compiling in a different directory from
3351     the source directory.
3353     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3354     options bits, the pointer it was passed was to an int instead of to an unsigned
3355     long int. This mattered only on 64-bit systems.
3357     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3358     generated) instead of pcre.in, which it its source. Also made the same change
3359     in several of the .c files.
3361     10. A new release of gcc defines printf() as a macro, which broke pcretest
3362     because it had an ifdef in the middle of a string argument for printf(). Fixed
3363     by using separate calls to printf().
3365     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3366     script, to force use of CR or LF instead of \n in the source. On non-Unix
3367     systems, the value can be set in config.h.
3369     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3370     absolute limit. Changed the text of the error message to make this clear, and
3371     likewise updated the man page.
3373     13. The limit of 99 on the number of capturing subpatterns has been removed.
3374     The new limit is 65535, which I hope will not be a "real" limit.
3377 nigel 51 Version 3.4 22-Aug-00
3378     ---------------------
3380     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3382     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3385 nigel 49 Version 3.3 01-Aug-00
3386     ---------------------
3388     1. If an octal character was given, but the value was greater than \377, it
3389     was not getting masked to the least significant bits, as documented. This could
3390     lead to crashes in some systems.
3392     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3393     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3395     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3396     These just pass their arguments on to (pcre_free)(), but they are provided
3397     because some uses of PCRE bind it to non-C systems that can call its functions,
3398     but cannot call free() or pcre_free() directly.
3400     4. Add "make test" as a synonym for "make check". Corrected some comments in
3401     the Makefile.
3403     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3404     Makefile.
3406     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3407     command called pgrep for grepping around the active processes.
3409     7. Added the beginnings of support for UTF-8 character strings.
3411     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3412     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3413     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3414     out for the ar command.)
3417 nigel 47 Version 3.2 12-May-00
3418     ---------------------
3420     This is purely a bug fixing release.
3422     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3423     of ZA. This was just one example of several cases that could provoke this bug,
3424     which was introduced by change 9 of version 2.00. The code for breaking
3425     infinite loops after an iteration that matches an empty string was't working
3426     correctly.
3428     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3429     when matched against abbab (for example). After matching an empty string, it
3430     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3431     caused it to match further down the string than it should.
3433     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3434     was there because it doesn't seem to be needed, and it causes trouble on some
3435     systems, as it is not a Standard C header. It has been removed.
3437     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3438     were reported on the Macintosh. The changes were from
3440     while ((c = *(++ptr)) != 0 && c != '\n');
3441     to
3442     while ((c = *(++ptr)) != 0 && c != '\n') ;
3444     Totally extraordinary, but if that's what it takes...
3446     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3447     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3448     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3449     assumes the way PCRE uses memmove() (always moving upwards).
3451     6. PCRE is being used in one environment where strchr() is not available. There
3452     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3453     faster code anyway.
3456 nigel 45 Version 3.1 09-Feb-00
3457     ---------------------
3459     The only change in this release is the fixing of some bugs in Makefile.in for
3460     the "install" target:
3462     (1) It was failing to install pcreposix.h.
3464     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3467 nigel 43 Version 3.0 01-Feb-00
3468     ---------------------
3469 nigel 41
3470     1. Add support for the /+ modifier to perltest (to output $` like it does in
3471     pcretest).
3473     2. Add support for the /g modifier to perltest.
3475     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3476     matches null strings.
3478     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3479     pattern. Perl treats empty patterns specially - it reuses the most recent
3480     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3481     effect.
3483     5. The POSIX interface was broken in that it was just handing over the POSIX
3484     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3485     required a bigger vector, with some working space on the end. This means that
3486     the POSIX wrapper now has to get and free some memory, and copy the results.
3488 nigel 43 6. Added some simple autoconf support, placing the test data and the
3489     documentation in separate directories, re-organizing some of the
3490     information files, and making it build pcre-config (a GNU standard). Also added
3491     libtool support for building PCRE as a shared library, which is now the
3492     default.
3493 nigel 41
3494 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3495     09 are not valid octal constants. Single digits will be used for minor values
3496     less than 10.
3498     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3499     existing programs that set these in the POSIX interface can use PCRE without
3500     modification.
3502     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3503     return all that pcre_info() returns, plus additional data. The pcre_info()
3504     function is retained for compatibility, but is considered to be obsolete.
3506     10. Added experimental recursion feature (?R) to handle one common case that
3507     Perl 5.6 will be able to do with (?p{...}).
3509     11. Added support for POSIX character classes like [:alpha:], which Perl is
3510     adopting.
3513 nigel 39 Version 2.08 31-Aug-99
3514     ----------------------
3516     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3517     trying to match at the startoffset position, but instead was moving forward to
3518     the next newline as if a previous match had failed.
3520     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3521     and could get into a loop if a null string was matched other than at the start
3522     of the subject.
3524     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3525     be distinguished at compile time, and for completeness also added PCRE_DATE.
3527     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3528     in GnuWin32 environments.
3531 nigel 37 Version 2.07 29-Jul-99
3532     ----------------------
3534     1. The documentation is now supplied in plain text form and HTML as well as in
3535     the form of man page sources.
3537     2. C++ compilers don't like assigning (void *) values to other pointer types.
3538     In particular this affects malloc(). Although there is no problem in Standard
3539     C, I've put in casts to keep C++ compilers happy.
3541     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3542     should be (const char *).
3544     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3545     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3546     However, I haven't made this a standard facility. The documentation doesn't
3547     mention it, and the Makefile doesn't support it.
3549     5. The Makefile now contains an "install" target, with editable destinations at
3550     the top of the file. The pcretest program is not installed.
3552     6. pgrep -V now gives the PCRE version number and date.
3554     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3555     causing the entire string to be ignored, instead of just the last character.
3557     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3558     non-matching string, it can take a very, very long time, even for strings of
3559     quite modest length, because of the nested recursion. PCRE now does better in
3560     some of these cases. It does this by remembering the last required literal
3561     character in the pattern, and pre-searching the subject to ensure it is present
3562     before running the real match. In other words, it applies a heuristic to detect
3563     some types of certain failure quickly, and in the above example, if presented
3564     with a string that has no trailing " it gives "no match" very quickly.
3566     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3567     other alternatives are tried instead.
3570 nigel 35 Version 2.06 09-Jun-99
3571     ----------------------
3573     1. Change pcretest's output for amount of store used to show just the code
3574     space, because the remainder (the data block) varies in size between 32-bit and
3575     64-bit systems.
3577     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3578     start matching at. This allows lookbehinds to work when searching for multiple
3579     occurrences in a string.
3581     3. Added additional options to pcretest for testing multiple occurrences:
3583     /+ outputs the rest of the string that follows a match
3584     /g loops for multiple occurrences, using the new startoffset argument
3585     /G loops for multiple occurrences by passing an incremented pointer
3587     4. PCRE wasn't doing the "first character" optimization for patterns starting
3588     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3589     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3590     the letter 'x'. On long subject strings, this gives a significant speed-up.
3593 nigel 33 Version 2.05 21-Apr-99
3594     ----------------------
3596     1. Changed the type of magic_number from int to long int so that it works
3597     properly on 16-bit systems.
3599     2. Fixed a bug which caused patterns starting with .* not to work correctly
3600     when the subject string contained newline characters. PCRE was assuming
3601     anchoring for such patterns in all cases, which is not correct because .* will
3602     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3603     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3604     must be retried after every newline in the subject.
3607 nigel 31 Version 2.04 18-Feb-99
3608     ----------------------
3610     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3611     computation of the store needed to hold the pattern was incorrect (too large).
3612     If such patterns were nested a few deep, this could multiply and become a real
3613     problem.
3615     2. Added /M option to pcretest to show the memory requirement of a specific
3616     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3618     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3619     compiled in such a way that the backtracking after subsequent failure was
3620     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3621     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3624 nigel 29 Version 2.03 02-Feb-99
3625     ----------------------
3627     1. Fixed typo and small mistake in man page.
3629 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3630     LICENCE file containing the conditions.
3631 nigel 29
3632     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3633     Perl, that is the internal \ allows the delimiter to be included in the
3634     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3635     the final delimiter, add \ to the end of the pattern (to test the error).
3637     4. Added the convenience functions for extracting substrings after a successful
3638     match. Updated pcretest to make it able to test these functions.
3641 nigel 27 Version 2.02 14-Jan-99
3642     ----------------------
3644     1. Initialized the working variables associated with each extraction so that
3645     their saving and restoring doesn't refer to uninitialized store.
3647     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3648     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3649     fix the problem.
3651     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3652     calls, and wasn't printing the correct value for compiling calls. Increased the
3653     default value of LOOPREPEAT, and the number of significant figures in the
3654     times.
3656     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3658     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3659     a building problem on Windows NT with a FAT file system.
3662 nigel 25 Version 2.01 21-Oct-98
3663     ----------------------
3665     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3666     to character tables built by pcre_maketables() in the current locale. If NULL
3667     is passed, the default tables are used.
3670 nigel 23 Version 2.00 24-Sep-98
3671 nigel 21 ----------------------
3673 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3674     it any more.
3676     2. Allow quantification of (?>) groups, and make it work correctly.
3678     3. The first character computation wasn't working for (?>) groups.
3680     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3681     end of the subject) and add 5.005's \z, which really does match only at the
3682     very end of the subject.
3684     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3686     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3687     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3688     localized options. All options to pcre_study() were also removed.
3690     7. Add other new features from 5.005:
3692     $(?<= positive lookbehind
3693     $(?<! negative lookbehind
3694     (?imsx-imsx) added the unsetting capability
3695     such a setting is global if at outer level; local otherwise
3696     (?imsx-imsx:) non-capturing groups with option setting
3697     (?(cond)re|re) conditional pattern matching
3699     A backreference to itself in a repeated group matches the previous
3700     captured string.
3702     8. General tidying up of studying (both automatic and via "study")
3703     consequential on the addition of new assertions.
3705     9. As in 5.005, unlimited repeated groups that could match an empty substring
3706     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3707     runtime if any iteration does actually match an empty substring.
3709     10. Include the RunTest script in the distribution.
3711     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3712     discrepancies, some of which were old and were also with respect to 5.004. They
3713     have now been fixed.
3716     Version 1.09 28-Apr-98
3717     ----------------------
3719 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3720     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3721     program crashes, or just wrong answers. This did not apply to negated classes
3722     containing more than one character, or to minima other than one.
3725 nigel 19 Version 1.08 27-Mar-98
3726     ----------------------
3728     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3730     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3731     latter must appear before anything that relies on it in the pattern.
3734 nigel 17 Version 1.07 16-Feb-98
3735     ----------------------
3737     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3738     repeat of a potentially empty string).
3741 nigel 15 Version 1.06 23-Jan-98
3742     ----------------------
3744     1. Added Markus Oberhumer's little patches for C++.
3746     2. Literal strings longer than 255 characters were broken.
3749 nigel 13 Version 1.05 23-Dec-97
3750     ----------------------
3752     1. Negated character classes containing more than one character were failing if
3753     PCRE_CASELESS was set at run time.
3756 nigel 11 Version 1.04 19-Dec-97
3757     ----------------------
3759     1. Corrected the man page, where some "const" qualifiers had been omitted.
3761     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3762     input s