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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.11 10-Oct-2010
5    ------------------------
6    
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    
14    
15    Version 8.10 25-Jun-2010
16    ------------------------
17    
18    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
19        THEN.
20    
21    2.  (*ACCEPT) was not working when inside an atomic group.
22    
23    3.  Inside a character class, \B is treated as a literal by default, but
24        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
25        causes the error). The code is unchanged, but I tidied the documentation.
26    
27    4.  Inside a character class, PCRE always treated \R and \X as literals,
28        whereas Perl faults them if its -w option is set. I have changed PCRE so
29        that it faults them when PCRE_EXTRA is set.
30    
31    5.  Added support for \N, which always matches any character other than
32        newline. (It is the same as "." when PCRE_DOTALL is not set.)
33    
34    6.  When compiling pcregrep with newer versions of gcc which may have
35        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
36        declared with attribute warn_unused_result" were given. Just casting the
37        result to (void) does not stop the warnings; a more elaborate fudge is
38        needed. I've used a macro to implement this.
39    
40    7.  Minor change to pcretest.c to avoid a compiler warning.
41    
42    8.  Added four artifical Unicode properties to help with an option to make
43        \s etc use properties (see next item). The new properties are: Xan
44        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
45    
46    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
47        use Unicode properties. (*UCP) at the start of a pattern can be used to set
48        this option. Modified pcretest to add /W to test this facility. Added
49        REG_UCP to make it available via the POSIX interface.
50    
51    10. Added --line-buffered to pcregrep.
52    
53    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
54        studied, and the match started with a letter with a code point greater than
55        127 whose first byte was different to the first byte of the other case of
56        the letter, the other case of this starting letter was not recognized
57        (#976).
58    
59    12. If a pattern that was studied started with a repeated Unicode property
60        test, for example, \p{Nd}+, there was the theoretical possibility of
61        setting up an incorrect bitmap of starting bytes, but fortunately it could
62        not have actually happened in practice until change 8 above was made (it
63        added property types that matched character-matching opcodes).
64    
65    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
66        possible starting bytes for non-anchored patterns.
67    
68    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
69        \R, and also a number of cases that involve Unicode properties, both
70        explicit and implicit when PCRE_UCP is set.
71    
72    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
73        input, it could crash or give wrong results if characters with values
74        greater than 0xc0 were present in the subject string. (Detail: it assumed
75        UTF-8 input when processing these items.)
76    
77    16. Added a lot of (int) casts to avoid compiler warnings in systems where
78        size_t is 64-bit (#991).
79    
80    17. Added a check for running out of memory when PCRE is compiled with
81        --disable-stack-for-recursion (#990).
82    
83    18. If the last data line in a file for pcretest does not have a newline on
84        the end, a newline was missing in the output.
85    
86    19. The default pcre_chartables.c file recognizes only ASCII characters (values
87        less than 128) in its various bitmaps. However, there is a facility for
88        generating tables according to the current locale when PCRE is compiled. It
89        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
90        characters, are recognized by isspace() and therefore were getting set in
91        these tables, and indeed these tables seem to approximate to ISO 8859. This
92        caused a problem in UTF-8 mode when pcre_study() was used to create a list
93        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
94        which of course cannot start UTF-8 characters. I have changed the code so
95        that only real ASCII characters (less than 128) and the correct starting
96        bytes for UTF-8 encodings are set for characters greater than 127 when in
97        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
98        altogether.)
99    
100    20. Added the /T option to pcretest so as to be able to run tests with non-
101        standard character tables, thus making it possible to include the tests
102        used for 19 above in the standard set of tests.
103    
104    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
105        reference to a subpattern the other side of a comment that contains an
106        opening parenthesis caused either an internal compiling error, or a
107        reference to the wrong subpattern.
108    
109    
110    Version 8.02 19-Mar-2010
111    ------------------------
112    
113    1.  The Unicode data tables have been updated to Unicode 5.2.0.
114    
115    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
116        configured.
117    
118    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
119        original author of that file, following a query about its status.
120    
121    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
122        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
123    
124    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
125        quantifier applied to a forward-referencing subroutine call, could compile
126        incorrect code or give the error "internal error: previously-checked
127        referenced subpattern not found".
128    
129    6.  Both MS Visual Studio and Symbian OS have problems with initializing
130        variables to point to external functions. For these systems, therefore,
131        pcre_malloc etc. are now initialized to local functions that call the
132        relevant global functions.
133    
134    7.  There were two entries missing in the vectors called coptable and poptable
135        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
136        I've fixed the data, and added a kludgy way of testing at compile time that
137        the lengths are correct (equal to the number of opcodes).
138    
139    8.  Following on from 7, I added a similar kludge to check the length of the
140        eint vector in pcreposix.c.
141    
142    9.  Error texts for pcre_compile() are held as one long string to avoid too
143        much relocation at load time. To find a text, the string is searched,
144        counting zeros. There was no check for running off the end of the string,
145        which could happen if a new error number was added without updating the
146        string.
147    
148    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
149    
150    11. \K was not working if it appeared in an atomic group or in a group that
151        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
152        \K is "not well defined" if used in an assertion. PCRE now accepts it if
153        the assertion is positive, but not if it is negative.
154    
155    12. Change 11 fortuitously reduced the size of the stack frame used in the
156        "match()" function of pcre_exec.c by one pointer. Forthcoming
157        implementation of support for (*MARK) will need an extra pointer on the
158        stack; I have reserved it now, so that the stack frame size does not
159        decrease.
160    
161    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
162        item in branch that calls a recursion is a subroutine call - as in the
163        second branch in the above example - was incorrectly given the compile-
164        time error "recursive call could loop indefinitely" because pcre_compile()
165        was not correctly checking the subroutine for matching a non-empty string.
166    
167    14. The checks for overrunning compiling workspace could trigger after an
168        overrun had occurred. This is a "should never occur" error, but it can be
169        triggered by pathological patterns such as hundreds of nested parentheses.
170        The checks now trigger 100 bytes before the end of the workspace.
171    
172    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
173    
174    
175    Version 8.01 19-Jan-2010
176    ------------------------
177    
178    1.  If a pattern contained a conditional subpattern with only one branch (in
179        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
180        computed the wrong minimum data length (which is of course zero for such
181        subpatterns). This could cause incorrect "no match" results.
182    
183    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
184        the pattern is reset in the first branch, pcre_compile() failed with
185        "internal error: code overflow at offset...". This happened only when
186        the reset was to the original external option setting. (An optimization
187        abstracts leading options settings into an external setting, which was the
188        cause of this.)
189    
190    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
191        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
192        assertion pattern did not match (meaning that the assertion was true), it
193        was incorrectly treated as false if the SKIP had been reached during the
194        matching. This also applied to assertions used as conditions.
195    
196    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
197        assertion subpattern, including such a pattern used as a condition,
198        unpredictable results occurred, instead of the error return
199        PCRE_ERROR_DFA_UITEM.
200    
201    5.  The C++ GlobalReplace function was not working like Perl for the special
202        situation when an empty string is matched. It now does the fancy magic
203        stuff that is necessary.
204    
205    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
206        removed. (These were left over from very, very early versions of PCRE.)
207    
208    7.  Some cosmetic changes to the code to make life easier when compiling it
209        as part of something else:
210    
211        (a) Change DEBUG to PCRE_DEBUG.
212    
213        (b) In pcre_compile(), rename the member of the "branch_chain" structure
214            called "current" as "current_branch", to prevent a collision with the
215            Linux macro when compiled as a kernel module.
216    
217        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
218            prevent a collision with the Linux macro when compiled as a kernel
219            module.
220    
221    8.  In pcre_compile() there are some checks for integer overflows that used to
222        cast potentially large values to (double). This has been changed to that
223        when building, a check for int64_t is made, and if it is found, it is used
224        instead, thus avoiding the use of floating point arithmetic. (There is no
225        other use of FP in PCRE.) If int64_t is not found, the fallback is to
226        double.
227    
228    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
229        2005 (difference between two addresses compared to an unsigned value).
230    
231    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
232        custom one, because of the following reported problem in Windows:
233    
234          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
235              under Win32.
236          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
237              therefore missing the function definition.
238          - The compiler thus generates a "C" signature for the test function.
239          - The linker fails to find the "C" function.
240          - PCRE fails to configure if asked to do so against libbz2.
241    
242    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
243        messages were output:
244    
245          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
246          rerunning libtoolize, to keep the correct libtool macros in-tree.
247          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
248    
249        I have done both of these things.
250    
251    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
252        most of the time, it *can* run out if it is given a pattern that contains a
253        runaway infinite recursion. I updated the discussion in the pcrestack man
254        page.
255    
256    13. Now that we have gone to the x.xx style of version numbers, the minor
257        version may start with zero. Using 08 or 09 is a bad idea because users
258        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
259        interpreted as invalid octal numbers. I've updated the previous comment in
260        configure.ac, and also added a check that gives an error if 08 or 09 are
261        used.
262    
263    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
264        causing partial matching to fail when the end of the subject matched \W
265        in a UTF-8 pattern where \W was quantified with a minimum of 3.
266    
267    15. There were some discrepancies between the declarations in pcre_internal.h
268        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
269        their definitions. The declarations used "const uschar *" and the
270        definitions used USPTR. Even though USPTR is normally defined as "const
271        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
272        reported that: "This difference in casting confuses some C++ compilers, for
273        example, SunCC recognizes above declarations as different functions and
274        generates broken code for hbpcre." I have changed the declarations to use
275        USPTR.
276    
277    16. GNU libtool is named differently on some systems. The autogen.sh script now
278        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
279        (FreeBSD).
280    
281    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
282        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
283        comment: "Figure out how to create a longlong from a string: strtoll and
284        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
285        instance, but it only takes 2 args instead of 3!"
286    
287    18. A subtle bug concerned with back references has been fixed by a change of
288        specification, with a corresponding code fix. A pattern such as
289        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
290        refers, was giving matches when it shouldn't. For example, xa=xaaa would
291        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
292        same bug. Such groups have to be quantified to be useful, or contained
293        inside another quantified group. (If there's no repetition, the reference
294        can never match.) The problem arises because, having left the group and
295        moved on to the rest of the pattern, a later failure that backtracks into
296        the group uses the captured value from the final iteration of the group
297        rather than the correct earlier one. I have fixed this in PCRE by forcing
298        any group that contains a reference to itself to be an atomic group; that
299        is, there cannot be any backtracking into it once it has completed. This is
300        similar to recursive and subroutine calls.
301    
302    
303    Version 8.00 19-Oct-09
304    ----------------------
305    
306    1.  The table for translating pcre_compile() error codes into POSIX error codes
307        was out-of-date, and there was no check on the pcre_compile() error code
308        being within the table. This could lead to an OK return being given in
309        error.
310    
311    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
312        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
313        in a Windows environment.
314    
315    3.  The pcregrep --count option prints the count for each file even when it is
316        zero, as does GNU grep. However, pcregrep was also printing all files when
317        --files-with-matches was added. Now, when both options are given, it prints
318        counts only for those files that have at least one match. (GNU grep just
319        prints the file name in this circumstance, but including the count seems
320        more useful - otherwise, why use --count?) Also ensured that the
321        combination -clh just lists non-zero counts, with no names.
322    
323    4.  The long form of the pcregrep -F option was incorrectly implemented as
324        --fixed_strings instead of --fixed-strings. This is an incompatible change,
325        but it seems right to fix it, and I didn't think it was worth preserving
326        the old behaviour.
327    
328    5.  The command line items --regex=pattern and --regexp=pattern were not
329        recognized by pcregrep, which required --regex pattern or --regexp pattern
330        (with a space rather than an '='). The man page documented the '=' forms,
331        which are compatible with GNU grep; these now work.
332    
333    6.  No libpcreposix.pc file was created for pkg-config; there was just
334        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
335    
336    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
337        when UCP support is not needed, by modifying the Python script that
338        generates it from Unicode data files. This should not matter if the module
339        is correctly used as a library, but I received one complaint about 50K of
340        unwanted data. My guess is that the person linked everything into his
341        program rather than using a library. Anyway, it does no harm.
342    
343    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
344        was a minimum greater than 1 for a wide character in a possessive
345        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
346        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
347        character. Chaos in the form of incorrect output or a compiling loop could
348        result.
349    
350    9.  The restrictions on what a pattern can contain when partial matching is
351        requested for pcre_exec() have been removed. All patterns can now be
352        partially matched by this function. In addition, if there are at least two
353        slots in the offset vector, the offset of the earliest inspected character
354        for the match and the offset of the end of the subject are set in them when
355        PCRE_ERROR_PARTIAL is returned.
356    
357    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
358        synonymous with PCRE_PARTIAL, for backwards compatibility, and
359        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
360        and may be more useful for multi-segment matching.
361    
362    11. Partial matching with pcre_exec() is now more intuitive. A partial match
363        used to be given if ever the end of the subject was reached; now it is
364        given only if matching could not proceed because another character was
365        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
366        string "Z", which now yields "no match" instead of "partial match". In the
367        case of pcre_dfa_exec(), "no match" is given if every matching path for the
368        final character ended with (*FAIL).
369    
370    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
371        if the pattern had a "must contain" character that was already found in the
372        earlier partial match, unless partial matching was again requested. For
373        example, with the pattern /dog.(body)?/, the "must contain" character is
374        "g". If the first part-match was for the string "dog", restarting with
375        "sbody" failed. This bug has been fixed.
376    
377    13. The string returned by pcre_dfa_exec() after a partial match has been
378        changed so that it starts at the first inspected character rather than the
379        first character of the match. This makes a difference only if the pattern
380        starts with a lookbehind assertion or \b or \B (\K is not supported by
381        pcre_dfa_exec()). It's an incompatible change, but it makes the two
382        matching functions compatible, and I think it's the right thing to do.
383    
384    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
385        so that the demonstration program is easily available in environments where
386        PCRE has not been installed from source.
387    
388    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
389        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
390        library.
391    
392    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
393        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
394        is not the first non-POSIX option to be added. Clearly some people find
395        these options useful.
396    
397    17. If a caller to the POSIX matching function regexec() passes a non-zero
398        value for nmatch with a NULL value for pmatch, the value of
399        nmatch is forced to zero.
400    
401    18. RunGrepTest did not have a test for the availability of the -u option of
402        the diff command, as RunTest does. It now checks in the same way as
403        RunTest, and also checks for the -b option.
404    
405    19. If an odd number of negated classes containing just a single character
406        interposed, within parentheses, between a forward reference to a named
407        subpattern and the definition of the subpattern, compilation crashed with
408        an internal error, complaining that it could not find the referenced
409        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
410        [The bug was that it was starting one character too far in when skipping
411        over the character class, thus treating the ] as data rather than
412        terminating the class. This meant it could skip too much.]
413    
414    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
415        /g option in pcretest when the pattern contains \K, which makes it possible
416        to have an empty string match not at the start, even when the pattern is
417        anchored. Updated pcretest and pcredemo to use this option.
418    
419    21. If the maximum number of capturing subpatterns in a recursion was greater
420        than the maximum at the outer level, the higher number was returned, but
421        with unset values at the outer level. The correct (outer level) value is
422        now given.
423    
424    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
425        PCRE did not set those parentheses (unlike Perl). I have now found a way to
426        make it do so. The string so far is captured, making this feature
427        compatible with Perl.
428    
429    23. The tests have been re-organized, adding tests 11 and 12, to make it
430        possible to check the Perl 5.10 features against Perl 5.10.
431    
432    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
433        pattern matches a fixed length string. PCRE did not allow this; now it
434        does. Neither allows recursion.
435    
436    25. I finally figured out how to implement a request to provide the minimum
437        length of subject string that was needed in order to match a given pattern.
438        (It was back references and recursion that I had previously got hung up
439        on.) This code has now been added to pcre_study(); it finds a lower bound
440        to the length of subject needed. It is not necessarily the greatest lower
441        bound, but using it to avoid searching strings that are too short does give
442        some useful speed-ups. The value is available to calling programs via
443        pcre_fullinfo().
444    
445    26. While implementing 25, I discovered to my embarrassment that pcretest had
446        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
447        study optimizations had never been tested with that matching function.
448        Oops. What is worse, even when it was passed study data, there was a bug in
449        pcre_dfa_exec() that meant it never actually used it. Double oops. There
450        were also very few tests of studied patterns with pcre_dfa_exec().
451    
452    27. If (?| is used to create subpatterns with duplicate numbers, they are now
453        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
454        on the other side of the coin, they are no longer allowed to have different
455        names, because these cannot be distinguished in PCRE, and this has caused
456        confusion. (This is a difference from Perl.)
457    
458    28. When duplicate subpattern names are present (necessarily with different
459        numbers, as required by 27 above), and a test is made by name in a
460        conditional pattern, either for a subpattern having been matched, or for
461        recursion in such a pattern, all the associated numbered subpatterns are
462        tested, and the overall condition is true if the condition is true for any
463        one of them. This is the way Perl works, and is also more like the way
464        testing by number works.
465    
466    
467    Version 7.9 11-Apr-09
468    ---------------------
469    
470    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
471        (pcretest), all targets were linked against these libraries. This included
472        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
473        libraries. This caused unwanted dependencies to be created. This problem
474        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
475        pcretest is linked with readline.
476    
477    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
478        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
479        moved outside it again, because FALSE and TRUE are already defined in AIX,
480        but BOOL is not.
481    
482    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
483        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
484    
485    4.  The pcregrep documentation said spaces were inserted as well as colons (or
486        hyphens) following file names and line numbers when outputting matching
487        lines. This is not true; no spaces are inserted. I have also clarified the
488        wording for the --colour (or --color) option.
489    
490    5.  In pcregrep, when --colour was used with -o, the list of matching strings
491        was not coloured; this is different to GNU grep, so I have changed it to be
492        the same.
493    
494    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
495        each matching line was coloured. Now it goes on to look for further matches
496        of any of the test patterns, which is the same behaviour as GNU grep.
497    
498    7.  A pattern that could match an empty string could cause pcregrep to loop; it
499        doesn't make sense to accept an empty string match in pcregrep, so I have
500        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
501        seems to be how GNU grep behaves.
502    
503    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
504        start or after a newline", because the conditional assertion was not being
505        correctly handled. The rule now is that both the assertion and what follows
506        in the first alternative must satisfy the test.
507    
508    9.  If auto-callout was enabled in a pattern with a conditional group whose
509        condition was an assertion, PCRE could crash during matching, both with
510        pcre_exec() and pcre_dfa_exec().
511    
512    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
513        used for matching.
514    
515    11. Unicode property support in character classes was not working for
516        characters (bytes) greater than 127 when not in UTF-8 mode.
517    
518    12. Added the -M command line option to pcretest.
519    
520    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
521    
522    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
523    
524    16. Added comments and documentation about mis-use of no_arg in the C++
525        wrapper.
526    
527    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
528        from Martin Jerabek that uses macro names for all relevant character and
529        string constants.
530    
531    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
532        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
533        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
534        these, but not everybody uses configure.
535    
536    19. A conditional group that had only one branch was not being correctly
537        recognized as an item that could match an empty string. This meant that an
538        enclosing group might also not be so recognized, causing infinite looping
539        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
540        with the subject "ab", where knowledge that the repeated group can match
541        nothing is needed in order to break the loop.
542    
543    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
544        exec(), but without supplying a callout function, matching went wrong.
545    
546    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
547        leak if the size of the offset vector was greater than 30. When the vector
548        is smaller, the saved offsets during recursion go onto a local stack
549        vector, but for larger vectors malloc() is used. It was failing to free
550        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
551        error, in fact).
552    
553    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
554        heapframe that is used only when UTF-8 support is enabled. This caused no
555        problem, but was untidy.
556    
557    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
558        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
559        included within another project.
560    
561    24. Steven Van Ingelgem's patches to add more options to the CMake support,
562        slightly modified by me:
563    
564          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
565              not building pcregrep.
566    
567          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
568              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
569    
570    25. Forward references, both numeric and by name, in patterns that made use of
571        duplicate group numbers, could behave incorrectly or give incorrect errors,
572        because when scanning forward to find the reference group, PCRE was not
573        taking into account the duplicate group numbers. A pattern such as
574        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
575    
576    26. Changed a few more instances of "const unsigned char *" to USPTR, making
577        the feature of a custom pointer more persuasive (as requested by a user).
578    
579    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
580        pcretest.c, inside #ifndefs, because it seems they are sometimes already
581        pre-defined.
582    
583    28. Added support for (*UTF8) at the start of a pattern.
584    
585    29. Arrange for flags added by the "release type" setting in CMake to be shown
586        in the configuration summary.
587    
588    
589    Version 7.8 05-Sep-08
590    ---------------------
591    
592    1.  Replaced UCP searching code with optimized version as implemented for Ad
593        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
594        stage table and inline lookup instead of a function, giving speed ups of 2
595        to 5 times on some simple patterns that I tested. Permission was given to
596        distribute the MultiStage2.py script that generates the tables (it's not in
597        the tarball, but is in the Subversion repository).
598    
599    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
600        scripts.
601    
602    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
603        a group with a zero qualifier. The result of the study could be incorrect,
604        or the function might crash, depending on the pattern.
605    
606    4.  Caseless matching was not working for non-ASCII characters in back
607        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
608        It now works when Unicode Property Support is available.
609    
610    5.  In pcretest, an escape such as \x{de} in the data was always generating
611        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
612        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
613        truncation.
614    
615    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
616    
617    7.  Added two (int) casts to pcregrep when printing the difference of two
618        pointers, in case they are 64-bit values.
619    
620    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
621        test 2 if it fails.
622    
623    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
624        and a #define of that name to empty if it is not externally set. This is to
625        allow users of MSVC to set it if necessary.
626    
627    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
628        the convenience functions in the pcre_get.c source file.
629    
630    11. An option change at the start of a pattern that had top-level alternatives
631        could cause overwriting and/or a crash. This command provoked a crash in
632        some environments:
633    
634          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
635    
636        This potential security problem was recorded as CVE-2008-2371.
637    
638    12. For a pattern where the match had to start at the beginning or immediately
639        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
640        pcre_dfa_exec() could read past the end of the passed subject if there was
641        no match. To help with detecting such bugs (e.g. with valgrind), I modified
642        pcretest so that it places the subject at the end of its malloc-ed buffer.
643    
644    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
645        exec() might read past the end of the data buffer in UTF-8 mode.
646    
647    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
648        the data contained the byte 0x85 as part of a UTF-8 character within its
649        first line. This applied both to normal and DFA matching.
650    
651    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
652        /^[^d]*?$/8 failed to match "abc".
653    
654    16. Added a missing copyright notice to pcrecpp_internal.h.
655    
656    17. Make it more clear in the documentation that values returned from
657        pcre_exec() in ovector are byte offsets, not character counts.
658    
659    18. Tidied a few places to stop certain compilers from issuing warnings.
660    
661    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
662        supplied by Stefan Weber. I made a further small update for 7.8 because
663        there is a change of source arrangements: the pcre_searchfuncs.c module is
664        replaced by pcre_ucd.c.
665    
666    
667    Version 7.7 07-May-08
668    ---------------------
669    
670    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
671        a string to a long long, pretend we don't even have a long long." This is
672        done by checking for the strtoq, strtoll, and _strtoi64 functions.
673    
674    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
675        pre-7.6 versions, which defined a global no_arg variable instead of putting
676        it in the RE class. (See also #8 below.)
677    
678    3.  Remove a line of dead code, identified by coverity and reported by Nuno
679        Lopes.
680    
681    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
682    
683        (1) The include/exclude patterns were being applied to the whole pathnames
684            of files, instead of just to the final components.
685    
686        (2) If there was more than one level of directory, the subdirectories were
687            skipped unless they satisfied the include/exclude conditions. This is
688            inconsistent with GNU grep (and could even be seen as contrary to the
689            pcregrep specification - which I improved to make it absolutely clear).
690            The action now is always to scan all levels of directory, and just
691            apply the include/exclude patterns to regular files.
692    
693    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
694        --exclude_dir in the tests to avoid scanning .svn directories.
695    
696    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
697        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
698        doesn't support NULs in patterns.
699    
700    7.  Added some missing "const"s to declarations of static tables in
701        pcre_compile.c and pcre_dfa_exec.c.
702    
703    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
704        caused by fix #2  above. (Subsequently also a second patch to fix the
705        first patch. And a third patch - this was a messy problem.)
706    
707    9.  Applied Craig's patch to remove the use of push_back().
708    
709    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
710        matching function regexec().
711    
712    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
713        which, however, unlike Perl's \g{...}, are subroutine calls, not back
714        references. PCRE supports relative numbers with this syntax (I don't think
715        Oniguruma does).
716    
717    12. Previously, a group with a zero repeat such as (...){0} was completely
718        omitted from the compiled regex. However, this means that if the group
719        was called as a subroutine from elsewhere in the pattern, things went wrong
720        (an internal error was given). Such groups are now left in the compiled
721        pattern, with a new opcode that causes them to be skipped at execution
722        time.
723    
724    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
725        to the way PCRE behaves:
726    
727        (a) A lone ] character is dis-allowed (Perl treats it as data).
728    
729        (b) A back reference to an unmatched subpattern matches an empty string
730            (Perl fails the current match path).
731    
732        (c) A data ] in a character class must be notated as \] because if the
733            first data character in a class is ], it defines an empty class. (In
734            Perl it is not possible to have an empty class.) The empty class []
735            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
736            The negative empty class [^] matches any one character, independently
737            of the DOTALL setting.
738    
739    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
740        non-existent subpattern following a character class starting with ']' and
741        containing () gave an internal compiling error instead of "reference to
742        non-existent subpattern". Fortunately, when the pattern did exist, the
743        compiled code was correct. (When scanning forwards to check for the
744        existencd of the subpattern, it was treating the data ']' as terminating
745        the class, so got the count wrong. When actually compiling, the reference
746        was subsequently set up correctly.)
747    
748    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
749        it was being rejected as not supported by pcre_dfa_exec(), even though
750        other assertions are supported. I have made pcre_dfa_exec() support
751        (*FAIL).
752    
753    16. The implementation of 13c above involved the invention of a new opcode,
754        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
755        cannot be changed at match time, I realized I could make a small
756        improvement to matching performance by compiling OP_ALLANY instead of
757        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
758        on the OP_ANY path.
759    
760    17. Compiling pcretest on Windows with readline support failed without the
761        following two fixes: (1) Make the unistd.h include conditional on
762        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
763    
764    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
765        ncurses library to be included for pcretest when ReadLine support is
766        requested, but also to allow for it to be overridden. This patch came from
767        Daniel Bergström.
768    
769    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
770        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
771        any errors with the current Unicode tables. Thanks to Peter Kankowski for
772        spotting this.
773    
774    
775    Version 7.6 28-Jan-08
776    ---------------------
777    
778    1.  A character class containing a very large number of characters with
779        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
780        overflow.
781    
782    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
783        HAVE_LONG_LONG is not defined.
784    
785    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
786        bring them up to date and include new features. This patch includes:
787    
788        - Fixed PH's badly added libz and libbz2 support.
789        - Fixed a problem with static linking.
790        - Added pcredemo. [But later removed - see 7 below.]
791        - Fixed dftables problem and added an option.
792        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
793            HAVE_LONG_LONG.
794        - Added readline support for pcretest.
795        - Added an listing of the option settings after cmake has run.
796    
797    4.  A user submitted a patch to Makefile that makes it easy to create
798        "pcre.dll" under mingw when using Configure/Make. I added stuff to
799        Makefile.am that cause it to include this special target, without
800        affecting anything else. Note that the same mingw target plus all
801        the other distribution libraries and programs are now supported
802        when configuring with CMake (see 6 below) instead of with
803        Configure/Make.
804    
805    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
806        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
807        exported in the Windows port". It has not yet been confirmed that the patch
808        solves the problem, but it does no harm.
809    
810    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
811        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
812        with CMake, and also correct the comment about stack recursion.
813    
814    7.  Remove the automatic building of pcredemo from the ./configure system and
815        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
816        of a program that users should build themselves after PCRE is installed, so
817        building it automatically is not really right. What is more, it gave
818        trouble in some build environments.
819    
820    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
821    
822    
823    Version 7.5 10-Jan-08
824    ---------------------
825    
826    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
827        values in parens when parsing an RE using the C++ wrapper."
828    
829    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
830        Characters greater than 255 were excluded from the class instead of being
831        included.
832    
833    3.  The same bug as (2) above applied to negated POSIX classes such as
834        [:^space:].
835    
836    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
837        defined or documented. It seems to have been a typo for PCRE_STATIC, so
838        I have changed it.
839    
840    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
841        first named subpattern) and a construct such as (?&a) would reference the
842        first named subpattern whose name started with "a" (in other words, the
843        length check was missing). Both these problems are fixed. "Subpattern name
844        expected" is now given for (?&) (a zero-length name), and this patch also
845        makes it give the same error for \k'' (previously it complained that that
846        was a reference to a non-existent subpattern).
847    
848    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
849        this is right because (?- can be followed by option settings as well as by
850        digits. I have, however, made the messages clearer.
851    
852    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
853        than the number used in the conditional) now cause a compile-time error.
854        This is actually not compatible with Perl, which accepts such patterns, but
855        treats the conditional as always being FALSE (as PCRE used to), but it
856        seems to me that giving a diagnostic is better.
857    
858    8.  Change "alphameric" to the more common word "alphanumeric" in comments
859        and messages.
860    
861    9.  Fix two occurrences of "backslash" in comments that should have been
862        "backspace".
863    
864    10. Remove two redundant lines of code that can never be obeyed (their function
865        was moved elsewhere).
866    
867    11. The program that makes PCRE's Unicode character property table had a bug
868        which caused it to generate incorrect table entries for sequences of
869        characters that have the same character type, but are in different scripts.
870        It amalgamated them into a single range, with the script of the first of
871        them. In other words, some characters were in the wrong script. There were
872        thirteen such cases, affecting characters in the following ranges:
873    
874          U+002b0 - U+002c1
875          U+0060c - U+0060d
876          U+0061e - U+00612
877          U+0064b - U+0065e
878          U+0074d - U+0076d
879          U+01800 - U+01805
880          U+01d00 - U+01d77
881          U+01d9b - U+01dbf
882          U+0200b - U+0200f
883          U+030fc - U+030fe
884          U+03260 - U+0327f
885          U+0fb46 - U+0fbb1
886          U+10450 - U+1049d
887    
888    12. The -o option (show only the matching part of a line) for pcregrep was not
889        compatible with GNU grep in that, if there was more than one match in a
890        line, it showed only the first of them. It now behaves in the same way as
891        GNU grep.
892    
893    13. If the -o and -v options were combined for pcregrep, it printed a blank
894        line for every non-matching line. GNU grep prints nothing, and pcregrep now
895        does the same. The return code can be used to tell if there were any
896        non-matching lines.
897    
898    14. Added --file-offsets and --line-offsets to pcregrep.
899    
900    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
901        infinitely looping recursion. The bug was that positive lookaheads were not
902        being skipped when checking for a possible empty match (negative lookaheads
903        and both kinds of lookbehind were skipped).
904    
905    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
906        inclusion of <windows.h> to before rather than after the definition of
907        INVALID_FILE_ATTRIBUTES (patch from David Byron).
908    
909    17. Specifying a possessive quantifier with a specific limit for a Unicode
910        character property caused pcre_compile() to compile bad code, which led at
911        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
912        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
913        caused the error; without that there was no problem.
914    
915    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
916    
917    19. Added --enable-pcretest-libreadline.
918    
919    20. In pcrecpp.cc, the variable 'count' was incremented twice in
920        RE::GlobalReplace(). As a result, the number of replacements returned was
921        double what it should be. I removed one of the increments, but Craig sent a
922        later patch that removed the other one (the right fix) and added unit tests
923        that check the return values (which was not done before).
924    
925    21. Several CMake things:
926    
927        (1) Arranged that, when cmake is used on Unix, the libraries end up with
928            the names libpcre and libpcreposix, not just pcre and pcreposix.
929    
930        (2) The above change means that pcretest and pcregrep are now correctly
931            linked with the newly-built libraries, not previously installed ones.
932    
933        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
934    
935    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
936        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
937        UTF-8 newline character). The key issue is that the pattern starts .*;
938        this means that the match must be either at the beginning, or after a
939        newline. The bug was in the code for advancing after a failed match and
940        checking that the new position followed a newline. It was not taking
941        account of UTF-8 characters correctly.
942    
943    23. PCRE was behaving differently from Perl in the way it recognized POSIX
944        character classes. PCRE was not treating the sequence [:...:] as a
945        character class unless the ... were all letters. Perl, however, seems to
946        allow any characters between [: and :], though of course it rejects as
947        unknown any "names" that contain non-letters, because all the known class
948        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
949        for example, whereas PCRE did not - it did not recognize a POSIX character
950        class. This seemed a bit dangerous, so the code has been changed to be
951        closer to Perl. The behaviour is not identical to Perl, because PCRE will
952        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
953        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
954        Perl does, and where it didn't before.
955    
956    24. Rewrite so as to remove the single use of %n from pcregrep because in some
957        Windows environments %n is disabled by default.
958    
959    
960    Version 7.4 21-Sep-07
961    ---------------------
962    
963    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
964        means that a class such as [\s] counted as "explicit reference to CR or
965        LF". That isn't really right - the whole point of the change was to try to
966        help when there was an actual mention of one of the two characters. So now
967        the change happens only if \r or \n (or a literal CR or LF) character is
968        encountered.
969    
970    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
971        of both had grown to the point where there were only 3 bits left.
972        Fortunately, there was spare space in the data structure, and so I have
973        moved the internal flags into a new 16-bit field to free up more option
974        bits.
975    
976    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
977        but did not set the internal JCHANGED flag - either of these is enough to
978        control the way the "get" function works - but the PCRE_INFO_JCHANGED
979        facility is supposed to tell if (?J) was ever used, so now (?J) at the
980        start sets both bits.
981    
982    4.  Added options (at build time, compile time, exec time) to change \R from
983        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
984    
985    5.  doc/pcresyntax.html was missing from the distribution.
986    
987    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
988        compatibility, even though it is no longer used.
989    
990    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
991        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
992        windows.h file is present (where different names are used). [This was
993        reversed later after testing - see 16 below.]
994    
995    8.  Changed all #include <config.h> to #include "config.h". There were also
996        some further <pcre.h> cases that I changed to "pcre.h".
997    
998    9.  When pcregrep was used with the --colour option, it missed the line ending
999        sequence off the lines that it output.
1000    
1001    10. It was pointed out to me that arrays of string pointers cause lots of
1002        relocations when a shared library is dynamically loaded. A technique of
1003        using a single long string with a table of offsets can drastically reduce
1004        these. I have refactored PCRE in four places to do this. The result is
1005        dramatic:
1006    
1007          Originally:                          290
1008          After changing UCP table:            187
1009          After changing error message table:   43
1010          After changing table of "verbs"       36
1011          After changing table of Posix names   22
1012    
1013        Thanks to the folks working on Gregex for glib for this insight.
1014    
1015    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1016        unicode-properties was also set.
1017    
1018    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1019    
1020    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1021        checked only for CRLF.
1022    
1023    14. Added casts to pcretest.c to avoid compiler warnings.
1024    
1025    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1026    
1027    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1028        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1029        entirely. This removes changes made in 7 above.
1030    
1031    17. The CMake files have been updated, and there is now more information about
1032        building with CMake in the NON-UNIX-USE document.
1033    
1034    
1035    Version 7.3 28-Aug-07
1036    ---------------------
1037    
1038     1. In the rejigging of the build system that eventually resulted in 7.1, the
1039        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1040        brackets there is not right, since it causes compilers to look for an
1041        installed pcre.h, not the version that is in the source that is being
1042        compiled (which of course may be different). I have changed it back to:
1043    
1044          #include "pcre.h"
1045    
1046        I have a vague recollection that the change was concerned with compiling in
1047        different directories, but in the new build system, that is taken care of
1048        by the VPATH setting the Makefile.
1049    
1050     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1051        when the subject happened to end in the byte 0x85 (e.g. if the last
1052        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1053        characters but of course it shouldn't be taken as a newline when it is part
1054        of another character. The bug was that, for an unlimited repeat of . in
1055        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1056        characters when looking for a newline.
1057    
1058     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1059    
1060     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1061        in debug output.
1062    
1063     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1064        long printing in the pcrecpp unittest when running under MinGW.
1065    
1066     6. ESC_K was left out of the EBCDIC table.
1067    
1068     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1069        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1070        limit also applies to "virtual nesting" when a pattern is recursive, and in
1071        this case 1000 isn't so big. I have been able to remove this limit at the
1072        expense of backing off one optimization in certain circumstances. Normally,
1073        when pcre_exec() would call its internal match() function recursively and
1074        immediately return the result unconditionally, it uses a "tail recursion"
1075        feature to save stack. However, when a subpattern that can match an empty
1076        string has an unlimited repetition quantifier, it no longer makes this
1077        optimization. That gives it a stack frame in which to save the data for
1078        checking that an empty string has been matched. Previously this was taken
1079        from the 1000-entry workspace that had been reserved. So now there is no
1080        explicit limit, but more stack is used.
1081    
1082     8. Applied Daniel's patches to solve problems with the import/export magic
1083        syntax that is required for Windows, and which was going wrong for the
1084        pcreposix and pcrecpp parts of the library. These were overlooked when this
1085        problem was solved for the main library.
1086    
1087     9. There were some crude static tests to avoid integer overflow when computing
1088        the size of patterns that contain repeated groups with explicit upper
1089        limits. As the maximum quantifier is 65535, the maximum group length was
1090        set at 30,000 so that the product of these two numbers did not overflow a
1091        32-bit integer. However, it turns out that people want to use groups that
1092        are longer than 30,000 bytes (though not repeat them that many times).
1093        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1094        made it possible to implement the integer overflow checks in a much more
1095        dynamic way, which I have now done. The artificial limitation on group
1096        length has been removed - we now have only the limit on the total length of
1097        the compiled pattern, which depends on the LINK_SIZE setting.
1098    
1099    10. Fixed a bug in the documentation for get/copy named substring when
1100        duplicate names are permitted. If none of the named substrings are set, the
1101        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1102        empty string.
1103    
1104    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1105        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1106        because the ] is interpreted as the first data character and the
1107        terminating ] is not found. PCRE has been made compatible with Perl in this
1108        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1109        cause memory overwriting.
1110    
1111    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1112        string has been matched (to stop an infinite loop). It was not recognizing
1113        a conditional subpattern that could match an empty string if that
1114        subpattern was within another subpattern. For example, it looped when
1115        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
1116        condition was not nested. This bug has been fixed.
1117    
1118    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1119        past the start of the subject in the presence of bytes with the top bit
1120        set, for example "\x8aBCD".
1121    
1122    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1123        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1124    
1125    14. Optimized (?!) to (*FAIL).
1126    
1127    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1128        This restricts code points to be within the range 0 to 0x10FFFF, excluding
1129        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1130        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1131        does: it's just the validity check that is more restrictive.
1132    
1133    16. Inserted checks for integer overflows during escape sequence (backslash)
1134        processing, and also fixed erroneous offset values for syntax errors during
1135        backslash processing.
1136    
1137    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1138        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1139    
1140    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1141        caused an overrun.
1142    
1143    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1144        something other than just ASCII characters) inside a group that had an
1145        unlimited repeat caused a loop at compile time (while checking to see
1146        whether the group could match an empty string).
1147    
1148    20. Debugging a pattern containing \p or \P could cause a crash. For example,
1149        [\P{Any}] did so. (Error in the code for printing property names.)
1150    
1151    21. An orphan \E inside a character class could cause a crash.
1152    
1153    22. A repeated capturing bracket such as (A)? could cause a wild memory
1154        reference during compilation.
1155    
1156    23. There are several functions in pcre_compile() that scan along a compiled
1157        expression for various reasons (e.g. to see if it's fixed length for look
1158        behind). There were bugs in these functions when a repeated \p or \P was
1159        present in the pattern. These operators have additional parameters compared
1160        with \d, etc, and these were not being taken into account when moving along
1161        the compiled data. Specifically:
1162    
1163        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1164            length.
1165    
1166        (b) An item such as \pL+ within a repeated group could cause crashes or
1167            loops.
1168    
1169        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1170            "reference to non-existent subpattern" error.
1171    
1172        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1173    
1174    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1175        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1176    
1177    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1178    
1179    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1180        character were causing crashes (broken optimization).
1181    
1182    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1183        \p or \P) caused a compile-time loop.
1184    
1185    28. More problems have arisen in unanchored patterns when CRLF is a valid line
1186        break. For example, the unstudied pattern [\r\n]A does not match the string
1187        "\r\nA" because change 7.0/46 below moves the current point on by two
1188        characters after failing to match at the start. However, the pattern \nA
1189        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1190        the same is true. There doesn't seem any very clean way out of this, but
1191        what I have chosen to do makes the common cases work: PCRE now takes note
1192        of whether there can be an explicit match for \r or \n anywhere in the
1193        pattern, and if so, 7.0/46 no longer applies. As part of this change,
1194        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1195        pattern has explicit CR or LF references.
1196    
1197    29. Added (*CR) etc for changing newline setting at start of pattern.
1198    
1199    
1200    Version 7.2 19-Jun-07
1201    ---------------------
1202    
1203     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1204        which is apparently normally available under Windows.
1205    
1206     2. Re-jig the pcregrep tests with different newline settings in an attempt
1207        to make them independent of the local environment's newline setting.
1208    
1209     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1210    
1211     4. Some of the "internals" tests were previously cut out when the link size
1212        was not 2, because the output contained actual offsets. The recent new
1213        "Z" feature of pcretest means that these can be cut out, making the tests
1214        usable with all link sizes.
1215    
1216     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1217        stack recursion. This gives a massive performance boost under BSD, but just
1218        a small improvement under Linux. However, it saves one field in the frame
1219        in all cases.
1220    
1221     6. Added more features from the forthcoming Perl 5.10:
1222    
1223        (a) (?-n) (where n is a string of digits) is a relative subroutine or
1224            recursion call. It refers to the nth most recently opened parentheses.
1225    
1226        (b) (?+n) is also a relative subroutine call; it refers to the nth next
1227            to be opened parentheses.
1228    
1229        (c) Conditions that refer to capturing parentheses can be specified
1230            relatively, for example, (?(-2)... or (?(+3)...
1231    
1232        (d) \K resets the start of the current match so that everything before
1233            is not part of it.
1234    
1235        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1236    
1237        (f) \g{name} is another synonym - part of Perl 5.10's unification of
1238            reference syntax.
1239    
1240        (g) (?| introduces a group in which the numbering of parentheses in each
1241            alternative starts with the same number.
1242    
1243        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1244    
1245     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1246        PCRE_INFO_JCHANGED.
1247    
1248     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
1249        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1250        for detecting groups that can match an empty string.
1251    
1252     9. A pattern with a very large number of alternatives (more than several
1253        hundred) was running out of internal workspace during the pre-compile
1254        phase, where pcre_compile() figures out how much memory will be needed. A
1255        bit of new cunning has reduced the workspace needed for groups with
1256        alternatives. The 1000-alternative test pattern now uses 12 bytes of
1257        workspace instead of running out of the 4096 that are available.
1258    
1259    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1260    
1261    11. Applied patch from Google to remove an optimization that didn't quite work.
1262        The report of the bug said:
1263    
1264          pcrecpp::RE("a*").FullMatch("aaa") matches, while
1265          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1266          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1267    
1268    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1269        it matched the wrong number of bytes.
1270    
1271    
1272    Version 7.1 24-Apr-07
1273    ---------------------
1274    
1275     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1276        that is more "standard", making use of automake and other Autotools. There
1277        is some re-arrangement of the files and adjustment of comments consequent
1278        on this.
1279    
1280     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1281        for recursive directory scanning broke on some systems because the files
1282        are not scanned in any specific order and on different systems the order
1283        was different. A call to "sort" has been inserted into RunGrepTest for the
1284        approprate test as a short-term fix. In the longer term there may be an
1285        alternative.
1286    
1287     3. I had an email from Eric Raymond about problems translating some of PCRE's
1288        man pages to HTML (despite the fact that I distribute HTML pages, some
1289        people do their own conversions for various reasons). The problems
1290        concerned the use of low-level troff macros .br and .in. I have therefore
1291        removed all such uses from the man pages (some were redundant, some could
1292        be replaced by .nf/.fi pairs). The 132html script that I use to generate
1293        HTML has been updated to handle .nf/.fi and to complain if it encounters
1294        .br or .in.
1295    
1296     4. Updated comments in configure.ac that get placed in config.h.in and also
1297        arranged for config.h to be included in the distribution, with the name
1298        config.h.generic, for the benefit of those who have to compile without
1299        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1300    
1301     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1302        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1303        makevp.bat for the current PCRE, using the additional files
1304        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1305    
1306     6. A Windows user reported a minor discrepancy with test 2, which turned out
1307        to be caused by a trailing space on an input line that had got lost in his
1308        copy. The trailing space was an accident, so I've just removed it.
1309    
1310     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1311        that is needed.
1312    
1313     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1314        as "const" (a) because they are and (b) because it helps the PHP
1315        maintainers who have recently made a script to detect big data structures
1316        in the php code that should be moved to the .rodata section. I remembered
1317        to update Builducptable as well, so it won't revert if ucptable.h is ever
1318        re-created.
1319    
1320     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1321        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1322        order to be able to cut out the UTF-8 tables in the latter when UTF-8
1323        support is not required. This saves 1.5-2K of code, which is important in
1324        some applications.
1325    
1326        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1327        so as not to refer to the tables, even though these functions will never be
1328        called when UTF-8 support is disabled. Otherwise there are problems with a
1329        shared library.
1330    
1331    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1332    
1333        (a) It was defining its arguments as char * instead of void *.
1334    
1335        (b) It was assuming that all moves were upwards in memory; this was true
1336            a long time ago when I wrote it, but is no longer the case.
1337    
1338        The emulated memove() is provided for those environments that have neither
1339        memmove() nor bcopy(). I didn't think anyone used it these days, but that
1340        is clearly not the case, as these two bugs were recently reported.
1341    
1342    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1343        and Detrail to create the HTML documentation, the .txt form of the man
1344        pages, and it removes trailing spaces from listed files. It also creates
1345        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1346        case, it wraps all the #defines with #ifndefs. This script should be run
1347        before "make dist".
1348    
1349    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1350        with Unicode property support.
1351    
1352        (a) For a maximizing quantifier, if the two different cases of the
1353            character were of different lengths in their UTF-8 codings (there are
1354            some cases like this - I found 11), and the matching function had to
1355            back up over a mixture of the two cases, it incorrectly assumed they
1356            were both the same length.
1357    
1358        (b) When PCRE was configured to use the heap rather than the stack for
1359            recursion during matching, it was not correctly preserving the data for
1360            the other case of a UTF-8 character when checking ahead for a match
1361            while processing a minimizing repeat. If the check also involved
1362            matching a wide character, but failed, corruption could cause an
1363            erroneous result when trying to check for a repeat of the original
1364            character.
1365    
1366    13. Some tidying changes to the testing mechanism:
1367    
1368        (a) The RunTest script now detects the internal link size and whether there
1369            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1370            values substituted by "configure". (The RunGrepTest script already did
1371            this for UTF-8.) The configure.ac script no longer substitutes the
1372            relevant variables.
1373    
1374        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1375            with length and offset values. This means that the output is different
1376            for different internal link sizes. Test 2 is skipped for link sizes
1377            other than 2 because of this, bypassing the problem. Unfortunately,
1378            there was also a test in test 3 (the locale tests) that used /B and
1379            failed for link sizes other than 2. Rather than cut the whole test out,
1380            I have added a new /Z option to pcretest that replaces the length and
1381            offset values with spaces. This is now used to make test 3 independent
1382            of link size. (Test 2 will be tidied up later.)
1383    
1384    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1385        segmentation fault instead of returning the appropriate error message.
1386    
1387    15. In multiline mode when the newline sequence was set to "any", the pattern
1388        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1389        This doesn't seem right; it now treats the CRLF combination as the line
1390        ending, and so does not match in that case. It's only a pattern such as ^$
1391        that would hit this one: something like ^ABC$ would have failed after \r
1392        and then tried again after \r\n.
1393    
1394    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1395        in an attempt to make files that differ only in their line terminators
1396        compare equal. This works on Linux.
1397    
1398    17. Under certain error circumstances pcregrep might try to free random memory
1399        as it exited. This is now fixed, thanks to valgrind.
1400    
1401    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1402        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1403        was because its rules for how to advance for /g after matching an empty
1404        string at the end of a line did not allow for this case. They now check for
1405        it specially.
1406    
1407    20. pcretest is supposed to handle patterns and data of any length, by
1408        extending its buffers when necessary. It was getting this wrong when the
1409        buffer for a data line had to be extended.
1410    
1411    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1412        CRLF as a newline sequence.
1413    
1414    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1415        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1416        I have nevertheless tidied it up.
1417    
1418    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1419    
1420    24. Added a man page for pcre-config.
1421    
1422    
1423    Version 7.0 19-Dec-06
1424    ---------------------
1425    
1426     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1427        moving to gcc 4.1.1.
1428    
1429     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1430        sys/time.h, which is documented as needed for this function. It doesn't
1431        seem to matter on Linux, but it showed up on some releases of OS X.
1432    
1433     3. It seems that there are systems where bytes whose values are greater than
1434        127 match isprint() in the "C" locale. The "C" locale should be the
1435        default when a C program starts up. In most systems, only ASCII printing
1436        characters match isprint(). This difference caused the output from pcretest
1437        to vary, making some of the tests fail. I have changed pcretest so that:
1438    
1439        (a) When it is outputting text in the compiled version of a pattern, bytes
1440            other than 32-126 are always shown as hex escapes.
1441    
1442        (b) When it is outputting text that is a matched part of a subject string,
1443            it does the same, unless a different locale has been set for the match
1444            (using the /L modifier). In this case, it uses isprint() to decide.
1445    
1446     4. Fixed a major bug that caused incorrect computation of the amount of memory
1447        required for a compiled pattern when options that changed within the
1448        pattern affected the logic of the preliminary scan that determines the
1449        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1450        that the computed length was too small. The symptoms of this bug were
1451        either the PCRE error "internal error: code overflow" from pcre_compile(),
1452        or a glibc crash with a message such as "pcretest: free(): invalid next
1453        size (fast)". Examples of patterns that provoked this bug (shown in
1454        pcretest format) are:
1455    
1456          /(?-x: )/x
1457          /(?x)(?-x: \s*#\s*)/
1458          /((?i)[\x{c0}])/8
1459          /(?i:[\x{c0}])/8
1460    
1461        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1462        is now done differently.
1463    
1464     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1465        wrapper classes; (b) implement a new function in the C++ scanner that is
1466        more efficient than the old way of doing things because it avoids levels of
1467        recursion in the regex matching; (c) add a paragraph to the documentation
1468        for the FullMatch() function.
1469    
1470     6. The escape sequence \n was being treated as whatever was defined as
1471        "newline". Not only was this contrary to the documentation, which states
1472        that \n is character 10 (hex 0A), but it also went horribly wrong when
1473        "newline" was defined as CRLF. This has been fixed.
1474    
1475     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1476        was being set to -1 for the "end of line" case (supposedly a value that no
1477        character can have). Though this value is never used (the check for end of
1478        line is "zero bytes in current character"), it caused compiler complaints.
1479        I've changed it to 0xffffffff.
1480    
1481     8. In pcre_version.c, the version string was being built by a sequence of
1482        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1483        string (as it is for production releases) called a macro with an empty
1484        argument. The C standard says the result of this is undefined. The gcc
1485        compiler treats it as an empty string (which was what was wanted) but it is
1486        reported that Visual C gives an error. The source has been hacked around to
1487        avoid this problem.
1488    
1489     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1490        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1491        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1492        of them did).
1493    
1494    10. Originally, pcretest opened its input and output without "b"; then I was
1495        told that "b" was needed in some environments, so it was added for release
1496        5.0 to both the input and output. (It makes no difference on Unix-like
1497        systems.) Later I was told that it is wrong for the input on Windows. I've
1498        now abstracted the modes into two macros, to make it easier to fiddle with
1499        them, and removed "b" from the input mode under Windows.
1500    
1501    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1502    
1503    12. Added -help and --help to pcretest as an official way of being reminded
1504        of the options.
1505    
1506    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1507        and pcrecpp.cc because they annoy compilers at high warning levels.
1508    
1509    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1510    
1511    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1512        scripts are not C programs :-) and which was not noticed because it works
1513        on Linux.
1514    
1515    16. pcretest is supposed to handle any length of pattern and data line (as one
1516        line or as a continued sequence of lines) by extending its input buffer if
1517        necessary. This feature was broken for very long pattern lines, leading to
1518        a string of junk being passed to pcre_compile() if the pattern was longer
1519        than about 50K.
1520    
1521    17. I have done a major re-factoring of the way pcre_compile() computes the
1522        amount of memory needed for a compiled pattern. Previously, there was code
1523        that made a preliminary scan of the pattern in order to do this. That was
1524        OK when PCRE was new, but as the facilities have expanded, it has become
1525        harder and harder to keep it in step with the real compile phase, and there
1526        have been a number of bugs (see for example, 4 above). I have now found a
1527        cunning way of running the real compile function in a "fake" mode that
1528        enables it to compute how much memory it would need, while actually only
1529        ever using a few hundred bytes of working memory and without too many
1530        tests of the mode. This should make future maintenance and development
1531        easier. A side effect of this work is that the limit of 200 on the nesting
1532        depth of parentheses has been removed (though this was never a serious
1533        limitation, I suspect). However, there is a downside: pcre_compile() now
1534        runs more slowly than before (30% or more, depending on the pattern). I
1535        hope this isn't a big issue. There is no effect on runtime performance.
1536    
1537    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1538        newline (only possible for the last line of a file) and it was a
1539        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1540    
1541    19. Added additional timing features to pcretest. (1) The -tm option now times
1542        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1543        separate command line item, by a number that specifies the number of
1544        repeats to use when timing. The default is 50000; this gives better
1545        precision, but takes uncomfortably long for very large patterns.
1546    
1547    20. Extended pcre_study() to be more clever in cases where a branch of a
1548        subpattern has no definite first character. For example, (a*|b*)[cd] would
1549        previously give no result from pcre_study(). Now it recognizes that the
1550        first character must be a, b, c, or d.
1551    
1552    21. There was an incorrect error "recursive call could loop indefinitely" if
1553        a subpattern (or the entire pattern) that was being tested for matching an
1554        empty string contained only one non-empty item after a nested subpattern.
1555        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1556        incorrectly, because the \d was being skipped in the check.
1557    
1558    22. The pcretest program now has a new pattern option /B and a command line
1559        option -b, which is equivalent to adding /B to every pattern. This causes
1560        it to show the compiled bytecode, without the additional information that
1561        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1562        is the same as /B/I).
1563    
1564    23. A new optimization is now able automatically to treat some sequences such
1565        as a*b as a*+b. More specifically, if something simple (such as a character
1566        or a simple class like \d) has an unlimited quantifier, and is followed by
1567        something that cannot possibly match the quantified thing, the quantifier
1568        is automatically "possessified".
1569    
1570    24. A recursive reference to a subpattern whose number was greater than 39
1571        went wrong under certain circumstances in UTF-8 mode. This bug could also
1572        have affected the operation of pcre_study().
1573    
1574    25. Realized that a little bit of performance could be had by replacing
1575        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1576    
1577    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1578    
1579    27. Possessive quantifiers such as a++ were previously implemented by turning
1580        them into atomic groups such as ($>a+). Now they have their own opcodes,
1581        which improves performance. This includes the automatically created ones
1582        from 23 above.
1583    
1584    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1585        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1586        the first matched character to be a colon. This applied both to named and
1587        numbered groups.
1588    
1589    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1590    
1591    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1592        building PCRE on Windows easier, so I have included it in the distribution.
1593    
1594    31. There is now a check in pcretest against a ridiculously large number being
1595        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1596        loop, the loop is abandoned.
1597    
1598    32. Forward references to subpatterns in conditions such as (?(2)...) where
1599        subpattern 2 is defined later cause pcre_compile() to search forwards in
1600        the pattern for the relevant set of parentheses. This search went wrong
1601        when there were unescaped parentheses in a character class, parentheses
1602        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1603    
1604    33. "Subroutine" calls and backreferences were previously restricted to
1605        referencing subpatterns earlier in the regex. This restriction has now
1606        been removed.
1607    
1608    34. Added a number of extra features that are going to be in Perl 5.10. On the
1609        whole, these are just syntactic alternatives for features that PCRE had
1610        previously implemented using the Python syntax or my own invention. The
1611        other formats are all retained for compatibility.
1612    
1613        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1614            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1615            also .NET compatible.
1616    
1617        (b) A recursion or subroutine call to a named group can now be defined as
1618            (?&name) as well as (?P>name).
1619    
1620        (c) A backreference to a named group can now be defined as \k<name> or
1621            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1622            5.10, are also .NET compatible.
1623    
1624        (d) A conditional reference to a named group can now use the syntax
1625            (?(<name>) or (?('name') as well as (?(name).
1626    
1627        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1628            groups (named and numbered) that are never evaluated inline, but can be
1629            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1630            is always false. There may be only one alternative in such a group.
1631    
1632        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1633            as the simple (?(R). The condition is true only if the most recent
1634            recursion is that of the given number or name. It does not search out
1635            through the entire recursion stack.
1636    
1637        (g) The escape \gN or \g{N} has been added, where N is a positive or
1638            negative number, specifying an absolute or relative reference.
1639    
1640    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1641        some "unreachable code" warnings.
1642    
1643    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1644        things, this adds five new scripts.
1645    
1646    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1647        There were also incompatibilities regarding the handling of \Q..\E inside
1648        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1649        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1650    
1651    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1652        matches an empty string, and forcibly breaks the loop. There were bugs in
1653        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1654        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1655        separate and independent bugs (that affected different cases) have been
1656        fixed.
1657    
1658    39. Refactored the code to abolish the use of different opcodes for small
1659        capturing bracket numbers. This is a tidy that I avoided doing when I
1660        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1661        The new approach is not only tidier, it makes it possible to reduce the
1662        memory needed to fix the previous bug (38).
1663    
1664    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1665        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1666        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1667        mode.
1668    
1669    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1670        report.
1671    
1672    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1673        copy construction and assignment in the C++ wrapper.
1674    
1675    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1676        couple of bugs that could have given wrong results in the "--newline=crlf"
1677        case.
1678    
1679    44. Added a number of casts and did some reorganization of signed/unsigned int
1680        variables following suggestions from Dair Grant. Also renamed the variable
1681        "this" as "item" because it is a C++ keyword.
1682    
1683    45. Arranged for dftables to add
1684    
1685          #include "pcre_internal.h"
1686    
1687        to pcre_chartables.c because without it, gcc 4.x may remove the array
1688        definition from the final binary if PCRE is built into a static library and
1689        dead code stripping is activated.
1690    
1691    46. For an unanchored pattern, if a match attempt fails at the start of a
1692        newline sequence, and the newline setting is CRLF or ANY, and the next two
1693        characters are CRLF, advance by two characters instead of one.
1694    
1695    
1696    Version 6.7 04-Jul-06
1697    ---------------------
1698    
1699     1. In order to handle tests when input lines are enormously long, pcretest has
1700        been re-factored so that it automatically extends its buffers when
1701        necessary. The code is crude, but this _is_ just a test program. The
1702        default size has been increased from 32K to 50K.
1703    
1704     2. The code in pcre_study() was using the value of the re argument before
1705        testing it for NULL. (Of course, in any sensible call of the function, it
1706        won't be NULL.)
1707    
1708     3. The memmove() emulation function in pcre_internal.h, which is used on
1709        systems that lack both memmove() and bcopy() - that is, hardly ever -
1710        was missing a "static" storage class specifier.
1711    
1712     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1713        containing an extended class (one that cannot be represented by a bitmap
1714        because it contains high-valued characters or Unicode property items, e.g.
1715        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1716        pattern, but PCRE should not loop if you do not (it no longer does).
1717        [Detail: two cases were found: (a) a repeated subpattern containing an
1718        extended class; (b) a recursive reference to a subpattern that followed a
1719        previous extended class. It wasn't skipping over the extended class
1720        correctly when UTF-8 mode was not set.]
1721    
1722     5. A negated single-character class was not being recognized as fixed-length
1723        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1724        compile error "lookbehind assertion is not fixed length".
1725    
1726     6. The RunPerlTest auxiliary script was showing an unexpected difference
1727        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1728        write a Perl script that can interpret lines of an input file either as
1729        byte characters or as UTF-8, which is what "perltest" was being required to
1730        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1731        can't do is switch easily at run time between having the "use utf8;" pragma
1732        or not. In the end, I fudged it by using the RunPerlTest script to insert
1733        "use utf8;" explicitly for the UTF-8 tests.
1734    
1735     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1736        the end of the subject string, contrary to the documentation and to what
1737        Perl does. This was true of both matching functions. Now it matches only at
1738        the start of the subject and immediately after *internal* newlines.
1739    
1740     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1741        a pointer to an int instead of a pointer to an unsigned long int. This
1742        caused problems on 64-bit systems.
1743    
1744     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1745        instance of the 'standard' template library not being so standard".
1746    
1747    10. There was no check on the number of named subpatterns nor the maximum
1748        length of a subpattern name. The product of these values is used to compute
1749        the size of the memory block for a compiled pattern. By supplying a very
1750        long subpattern name and a large number of named subpatterns, the size
1751        computation could be caused to overflow. This is now prevented by limiting
1752        the length of names to 32 characters, and the number of named subpatterns
1753        to 10,000.
1754    
1755    11. Subpatterns that are repeated with specific counts have to be replicated in
1756        the compiled pattern. The size of memory for this was computed from the
1757        length of the subpattern and the repeat count. The latter is limited to
1758        65535, but there was no limit on the former, meaning that integer overflow
1759        could in principle occur. The compiled length of a repeated subpattern is
1760        now limited to 30,000 bytes in order to prevent this.
1761    
1762    12. Added the optional facility to have named substrings with the same name.
1763    
1764    13. Added the ability to use a named substring as a condition, using the
1765        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1766        are numbers (not recommended). Forward references are permitted.
1767    
1768    14. Added forward references in named backreferences (if you see what I mean).
1769    
1770    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1771        pattern could run off the end of the subject. For example, the pattern
1772        "(?s)(.{1,5})"8 did this with the subject "ab".
1773    
1774    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1775        PCRE_CASELESS was set when matching characters that were quantified with ?
1776        or *.
1777    
1778    17. A character class other than a single negated character that had a minimum
1779        but no maximum quantifier - for example [ab]{6,} - was not handled
1780        correctly by pce_dfa_exec(). It would match only one character.
1781    
1782    18. A valid (though odd) pattern that looked like a POSIX character
1783        class but used an invalid character after [ (for example [[,abc,]]) caused
1784        pcre_compile() to give the error "Failed: internal error: code overflow" or
1785        in some cases to crash with a glibc free() error. This could even happen if
1786        the pattern terminated after [[ but there just happened to be a sequence of
1787        letters, a binary zero, and a closing ] in the memory that followed.
1788    
1789    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1790        over the years. Originally (before any Unicode support), just the bottom 8
1791        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1792        output from "man perlunicode" includes this:
1793    
1794          The regular expression compiler produces polymorphic opcodes.  That
1795          is, the pattern adapts to the data and automatically switches to
1796          the Unicode character scheme when presented with Unicode data--or
1797          instead uses a traditional byte scheme when presented with byte
1798          data.
1799    
1800        Sadly, a wide octal escape does not cause a switch, and in a string with
1801        no other multibyte characters, these octal escapes are treated as before.
1802        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1803        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1804        Unicode string.
1805    
1806        I have not perpetrated such confusion in PCRE. Up till now, it took just
1807        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1808        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1809        translate to the appropriate multibyte character.
1810    
1811    29. Applied some refactoring to reduce the number of warnings from Microsoft
1812        and Borland compilers. This has included removing the fudge introduced
1813        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1814        a warning about an unused variable.
1815    
1816    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1817        characters since release 4.0, because Perl (from release 5.004) does not.
1818        [Or at least, is documented not to: some releases seem to be in conflict
1819        with the documentation.] However, when a pattern was studied with
1820        pcre_study() and all its branches started with \s, PCRE still included VT
1821        as a possible starting character. Of course, this did no harm; it just
1822        caused an unnecessary match attempt.
1823    
1824    22. Removed a now-redundant internal flag bit that recorded the fact that case
1825        dependency changed within the pattern. This was once needed for "required
1826        byte" processing, but is no longer used. This recovers a now-scarce options
1827        bit. Also moved the least significant internal flag bit to the most-
1828        significant bit of the word, which was not previously used (hangover from
1829        the days when it was an int rather than a uint) to free up another bit for
1830        the future.
1831    
1832    23. Added support for CRLF line endings as well as CR and LF. As well as the
1833        default being selectable at build time, it can now be changed at runtime
1834        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1835        specify that it is scanning data with non-default line endings.
1836    
1837    24. Changed the definition of CXXLINK to make it agree with the definition of
1838        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1839    
1840    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1841        recursions. This makes a big different to stack usage for some patterns.
1842    
1843    26. If a subpattern containing a named recursion or subroutine reference such
1844        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1845        the space required for the compiled pattern went wrong and gave too small a
1846        value. Depending on the environment, this could lead to "Failed: internal
1847        error: code overflow at offset 49" or "glibc detected double free or
1848        corruption" errors.
1849    
1850    27. Applied patches from Google (a) to support the new newline modes and (b) to
1851        advance over multibyte UTF-8 characters in GlobalReplace.
1852    
1853    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1854        difference for some implementation of PCRE in some Windows version.
1855    
1856    29. Added some extra testing facilities to pcretest:
1857    
1858        \q<number>   in a data line sets the "match limit" value
1859        \Q<number>   in a data line sets the "match recursion limt" value
1860        -S <number>  sets the stack size, where <number> is in megabytes
1861    
1862        The -S option isn't available for Windows.
1863    
1864    
1865    Version 6.6 06-Feb-06
1866    ---------------------
1867    
1868     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1869        in pcreposix.h. I have copied the definition from pcre.h.
1870    
1871     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1872        because pcre.h is no longer a built file.
1873    
1874     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1875        not normally included in the compiled code.
1876    
1877    
1878    Version 6.5 01-Feb-06
1879    ---------------------
1880    
1881     1. When using the partial match feature with pcre_dfa_exec(), it was not
1882        anchoring the second and subsequent partial matches at the new starting
1883        point. This could lead to incorrect results. For example, with the pattern
1884        /1234/, partially matching against "123" and then "a4" gave a match.
1885    
1886     2. Changes to pcregrep:
1887    
1888        (a) All non-match returns from pcre_exec() were being treated as failures
1889            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1890            error message is output. Some extra information is given for the
1891            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1892            probably the only errors that are likely to be caused by users (by
1893            specifying a regex that has nested indefinite repeats, for instance).
1894            If there are more than 20 of these errors, pcregrep is abandoned.
1895    
1896        (b) A binary zero was treated as data while matching, but terminated the
1897            output line if it was written out. This has been fixed: binary zeroes
1898            are now no different to any other data bytes.
1899    
1900        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1901            used to set a locale for matching. The --locale=xxxx long option has
1902            been added (no short equivalent) to specify a locale explicitly on the
1903            pcregrep command, overriding the environment variables.
1904    
1905        (d) When -B was used with -n, some line numbers in the output were one less
1906            than they should have been.
1907    
1908        (e) Added the -o (--only-matching) option.
1909    
1910        (f) If -A or -C was used with -c (count only), some lines of context were
1911            accidentally printed for the final match.
1912    
1913        (g) Added the -H (--with-filename) option.
1914    
1915        (h) The combination of options -rh failed to suppress file names for files
1916            that were found from directory arguments.
1917    
1918        (i) Added the -D (--devices) and -d (--directories) options.
1919    
1920        (j) Added the -F (--fixed-strings) option.
1921    
1922        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1923    
1924        (l) Added the --colo(u)r option.
1925    
1926        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1927            is not present by default.
1928    
1929     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1930        items such as (?R) or (?1), when the recursion could match a number of
1931        alternatives. If it matched one of the alternatives, but subsequently,
1932        outside the recursion, there was a failure, the code tried to back up into
1933        the recursion. However, because of the way PCRE is implemented, this is not
1934        possible, and the result was an incorrect result from the match.
1935    
1936        In order to prevent this happening, the specification of recursion has
1937        been changed so that all such subpatterns are automatically treated as
1938        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1939    
1940     4. I had overlooked the fact that, in some locales, there are characters for
1941        which isalpha() is true but neither isupper() nor islower() are true. In
1942        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1943        and ordfeminine) are like this. This affected the treatment of \w and \W
1944        when they appeared in character classes, but not when they appeared outside
1945        a character class. The bit map for "word" characters is now created
1946        separately from the results of isalnum() instead of just taking it from the
1947        upper, lower, and digit maps. (Plus the underscore character, of course.)
1948    
1949     5. The above bug also affected the handling of POSIX character classes such as
1950        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1951        permanent tables. Instead, the bit maps for such a class were previously
1952        created as the appropriate unions of the upper, lower, and digit bitmaps.
1953        Now they are created by subtraction from the [[:word:]] class, which has
1954        its own bitmap.
1955    
1956     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1957        It is created by subtracting the vertical space characters (\x09, \x0a,
1958        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1959        subtraction was done in the overall bitmap for a character class, meaning
1960        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1961        be recognized. This bug has been fixed.
1962    
1963     7. Patches from the folks at Google:
1964    
1965          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1966          real life, but is still worth protecting against".
1967    
1968          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1969          regular expressions".
1970    
1971          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1972          have it.
1973    
1974          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1975          "configure" and the latter not, in order to fix a problem somebody had
1976          with compiling the Arg class on HP-UX.
1977    
1978          (e) Improve the error-handling of the C++ wrapper a little bit.
1979    
1980          (f) New tests for checking recursion limiting.
1981    
1982     8. The pcre_memmove() function, which is used only if the environment does not
1983        have a standard memmove() function (and is therefore rarely compiled),
1984        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1985        returning a result (though PCRE never actually uses the result).
1986    
1987     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1988        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1989        returned instead of calling malloc() with an overflowing number that would
1990        most likely cause subsequent chaos.
1991    
1992    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1993    
1994    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1995        with this option is matched, the nmatch and pmatch options of regexec() are
1996        ignored.
1997    
1998    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1999        provided in case anyone wants to the the POSIX interface with UTF-8
2000        strings.
2001    
2002    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2003        C++ linking (needed for some HP-UX environments).
2004    
2005    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2006        (unused parameter) and in the pcre_printint() function (omitted "default"
2007        switch label when the default is to do nothing).
2008    
2009    15. Added some code to make it possible, when PCRE is compiled as a C++
2010        library, to replace subject pointers for pcre_exec() with a smart pointer
2011        class, thus making it possible to process discontinuous strings.
2012    
2013    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2014        much the same function. They were added by different people who were trying
2015        to make PCRE easy to compile on non-Unix systems. It has been suggested
2016        that PCRE_EXPORT be abolished now that there is more automatic apparatus
2017        for compiling on Windows systems. I have therefore replaced it with
2018        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2019        defaults to "extern" for C or "extern C" for C++, which works fine on
2020        Unix-like systems. It is now possible to override the value of PCRE_DATA_
2021        SCOPE with something explicit in config.h. In addition:
2022    
2023        (a) pcreposix.h still had just "extern" instead of either of these macros;
2024            I have replaced it with PCRE_DATA_SCOPE.
2025    
2026        (b) Functions such as _pcre_xclass(), which are internal to the library,
2027            but external in the C sense, all had PCRE_EXPORT in their definitions.
2028            This is apparently wrong for the Windows case, so I have removed it.
2029            (It makes no difference on Unix-like systems.)
2030    
2031    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2032        of recursive calls to match(). This is different to MATCH_LIMIT because
2033        that limits the total number of calls to match(), not all of which increase
2034        the depth of recursion. Limiting the recursion depth limits the amount of
2035        stack (or heap if NO_RECURSE is set) that is used. The default can be set
2036        when PCRE is compiled, and changed at run time. A patch from Google adds
2037        this functionality to the C++ interface.
2038    
2039    18. Changes to the handling of Unicode character properties:
2040    
2041        (a) Updated the table to Unicode 4.1.0.
2042    
2043        (b) Recognize characters that are not in the table as "Cn" (undefined).
2044    
2045        (c) I revised the way the table is implemented to a much improved format
2046            which includes recognition of ranges. It now supports the ranges that
2047            are defined in UnicodeData.txt, and it also amalgamates other
2048            characters into ranges. This has reduced the number of entries in the
2049            table from around 16,000 to around 3,000, thus reducing its size
2050            considerably. I realized I did not need to use a tree structure after
2051            all - a binary chop search is just as efficient. Having reduced the
2052            number of entries, I extended their size from 6 bytes to 8 bytes to
2053            allow for more data.
2054    
2055        (d) Added support for Unicode script names via properties such as \p{Han}.
2056    
2057    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2058        matching that character.
2059    
2060    20. When matching a repeated Unicode property with a minimum greater than zero,
2061        (for example \pL{2,}), PCRE could look past the end of the subject if it
2062        reached it while seeking the minimum number of characters. This could
2063        happen only if some of the characters were more than one byte long, because
2064        there is a check for at least the minimum number of bytes.
2065    
2066    21. Refactored the implementation of \p and \P so as to be more general, to
2067        allow for more different types of property in future. This has changed the
2068        compiled form incompatibly. Anybody with saved compiled patterns that use
2069        \p or \P will have to recompile them.
2070    
2071    22. Added "Any" and "L&" to the supported property types.
2072    
2073    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2074        but give a compile time error if the value is greater than 0xff.
2075    
2076    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2077        accidentally not being installed or uninstalled.
2078    
2079    25. The pcre.h file was built from pcre.h.in, but the only changes that were
2080        made were to insert the current release number. This seemed silly, because
2081        it made things harder for people building PCRE on systems that don't run
2082        "configure". I have turned pcre.h into a distributed file, no longer built
2083        by "configure", with the version identification directly included. There is
2084        no longer a pcre.h.in file.
2085    
2086        However, this change necessitated a change to the pcre-config script as
2087        well. It is built from pcre-config.in, and one of the substitutions was the
2088        release number. I have updated configure.ac so that ./configure now finds
2089        the release number by grepping pcre.h.
2090    
2091    26. Added the ability to run the tests under valgrind.
2092    
2093    
2094    Version 6.4 05-Sep-05
2095    ---------------------
2096    
2097     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2098        "--" to be printed when multiple files were scanned, even when none of the
2099        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2100        consider it to be a bug, and have restored the previous behaviour.
2101    
2102     2. A couple of code tidies to get rid of compiler warnings.
2103    
2104     3. The pcretest program used to cheat by referring to symbols in the library
2105        whose names begin with _pcre_. These are internal symbols that are not
2106        really supposed to be visible externally, and in some environments it is
2107        possible to suppress them. The cheating is now confined to including
2108        certain files from the library's source, which is a bit cleaner.
2109    
2110     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2111        file's purpose clearer.
2112    
2113     5. Reorganized pcre_ucp_findchar().
2114    
2115    
2116    Version 6.3 15-Aug-05
2117    ---------------------
2118    
2119     1. The file libpcre.pc.in did not have general read permission in the tarball.
2120    
2121     2. There were some problems when building without C++ support:
2122    
2123        (a) If C++ support was not built, "make install" and "make test" still
2124            tried to test it.
2125    
2126        (b) There were problems when the value of CXX was explicitly set. Some
2127            changes have been made to try to fix these, and ...
2128    
2129        (c) --disable-cpp can now be used to explicitly disable C++ support.
2130    
2131        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2132            backslash in a target when C++ was disabled. This confuses some
2133            versions of "make", apparently. Using an intermediate variable solves
2134            this. (Same for CPP_LOBJ.)
2135    
2136     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2137        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2138        necessary on certain architectures.
2139    
2140     4. Added a setting of -export-symbols-regex to the link command to remove
2141        those symbols that are exported in the C sense, but actually are local
2142        within the library, and not documented. Their names all begin with
2143        "_pcre_". This is not a perfect job, because (a) we have to except some
2144        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2145        available (and never for static libraries). I have made a note to try to
2146        find a way round (a) in the future.
2147    
2148    
2149    Version 6.2 01-Aug-05
2150    ---------------------
2151    
2152     1. There was no test for integer overflow of quantifier values. A construction
2153        such as {1111111111111111} would give undefined results. What is worse, if
2154        a minimum quantifier for a parenthesized subpattern overflowed and became
2155        negative, the calculation of the memory size went wrong. This could have
2156        led to memory overwriting.
2157    
2158     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2159    
2160     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2161        operating environments where this matters.
2162    
2163     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2164        PCRE options from within the C++ wrapper.
2165    
2166     5. Named capturing subpatterns were not being correctly counted when a pattern
2167        was compiled. This caused two problems: (a) If there were more than 100
2168        such subpatterns, the calculation of the memory needed for the whole
2169        compiled pattern went wrong, leading to an overflow error. (b) Numerical
2170        back references of the form \12, where the number was greater than 9, were
2171        not recognized as back references, even though there were sufficient
2172        previous subpatterns.
2173    
2174     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2175        versions of gcc, e.g. 2.95.4.
2176    
2177    
2178    Version 6.1 21-Jun-05
2179    ---------------------
2180    
2181     1. There was one reference to the variable "posix" in pcretest.c that was not
2182        surrounded by "#if !defined NOPOSIX".
2183    
2184     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2185        the cross-check on the old pcre_info() function, for the benefit of the
2186        cut-down version of PCRE that is currently imported into Exim.
2187    
2188     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2189        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2190        patterns that start (?i) but I don't think that matters. The use of (?i) is
2191        just an example; this all applies to the other options as well.
2192    
2193     4. Since libtool seems to echo the compile commands it is issuing, the output
2194        from "make" can be reduced a bit by putting "@" in front of each libtool
2195        compile command.
2196    
2197     5. Patch from the folks at Google for configure.in to be a bit more thorough
2198        in checking for a suitable C++ installation before trying to compile the
2199        C++ stuff. This should fix a reported problem when a compiler was present,
2200        but no suitable headers.
2201    
2202     6. The man pages all had just "PCRE" as their title. I have changed them to
2203        be the relevant file name. I have also arranged that these names are
2204        retained in the file doc/pcre.txt, which is a concatenation in text format
2205        of all the man pages except the little individual ones for each function.
2206    
2207     7. The NON-UNIX-USE file had not been updated for the different set of source
2208        files that come with release 6. I also added a few comments about the C++
2209        wrapper.
2210    
2211    
2212    Version 6.0 07-Jun-05
2213    ---------------------
2214    
2215     1. Some minor internal re-organization to help with my DFA experiments.
2216    
2217     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2218        didn't matter for the library itself when fully configured, but did matter
2219        when compiling without UCP support, or within Exim, where the ucp files are
2220        not imported.
2221    
2222     3. Refactoring of the library code to split up the various functions into
2223        different source modules. The addition of the new DFA matching code (see
2224        below) to a single monolithic source would have made it really too
2225        unwieldy, quite apart from causing all the code to be include in a
2226        statically linked application, when only some functions are used. This is
2227        relevant even without the DFA addition now that patterns can be compiled in
2228        one application and matched in another.
2229    
2230        The downside of splitting up is that there have to be some external
2231        functions and data tables that are used internally in different modules of
2232        the library but which are not part of the API. These have all had their
2233        names changed to start with "_pcre_" so that they are unlikely to clash
2234        with other external names.
2235    
2236     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2237        a different (DFA) algorithm. Although it is slower than the original
2238        function, it does have some advantages for certain types of matching
2239        problem.
2240    
2241     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2242        including restarting after a partial match.
2243    
2244     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2245        defined when compiling for Windows was sent to me. I have put it into the
2246        code, though I have no means of testing or verifying it.
2247    
2248     7. Added the pcre_refcount() auxiliary function.
2249    
2250     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2251        match before or at the first newline in the subject string. In pcretest,
2252        the /f option on a pattern can be used to set this.
2253    
2254     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2255        would behave wrongly. This has been present in PCRE since release 4.0.
2256    
2257    10. A number of changes to the pcregrep command:
2258    
2259        (a) Refactored how -x works; insert ^(...)$ instead of setting
2260            PCRE_ANCHORED and checking the length, in preparation for adding
2261            something similar for -w.
2262    
2263        (b) Added the -w (match as a word) option.
2264    
2265        (c) Refactored the way lines are read and buffered so as to have more
2266            than one at a time available.
2267    
2268        (d) Implemented a pcregrep test script.
2269    
2270        (e) Added the -M (multiline match) option. This allows patterns to match
2271            over several lines of the subject. The buffering ensures that at least
2272            8K, or the rest of the document (whichever is the shorter) is available
2273            for matching (and similarly the previous 8K for lookbehind assertions).
2274    
2275        (f) Changed the --help output so that it now says
2276    
2277              -w, --word-regex(p)
2278    
2279            instead of two lines, one with "regex" and the other with "regexp"
2280            because that confused at least one person since the short forms are the
2281            same. (This required a bit of code, as the output is generated
2282            automatically from a table. It wasn't just a text change.)
2283    
2284        (g) -- can be used to terminate pcregrep options if the next thing isn't an
2285            option but starts with a hyphen. Could be a pattern or a path name
2286            starting with a hyphen, for instance.
2287    
2288        (h) "-" can be given as a file name to represent stdin.
2289    
2290        (i) When file names are being printed, "(standard input)" is used for
2291            the standard input, for compatibility with GNU grep. Previously
2292            "<stdin>" was used.
2293    
2294        (j) The option --label=xxx can be used to supply a name to be used for
2295            stdin when file names are being printed. There is no short form.
2296    
2297        (k) Re-factored the options decoding logic because we are going to add
2298            two more options that take data. Such options can now be given in four
2299            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2300    
2301        (l) Added the -A, -B, and -C options for requesting that lines of context
2302            around matches be printed.
2303    
2304        (m) Added the -L option to print the names of files that do not contain
2305            any matching lines, that is, the complement of -l.
2306    
2307        (n) The return code is 2 if any file cannot be opened, but pcregrep does
2308            continue to scan other files.
2309    
2310        (o) The -s option was incorrectly implemented. For compatibility with other
2311            greps, it now suppresses the error message for a non-existent or non-
2312            accessible file (but not the return code). There is a new option called
2313            -q that suppresses the output of matching lines, which was what -s was
2314            previously doing.
2315    
2316        (p) Added --include and --exclude options to specify files for inclusion
2317            and exclusion when recursing.
2318    
2319    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2320        Hopefully, it now does.
2321    
2322    12. Missing cast in pcre_study().
2323    
2324    13. Added an "uninstall" target to the makefile.
2325    
2326    14. Replaced "extern" in the function prototypes in Makefile.in with
2327        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2328        world, but is set differently for Windows.
2329    
2330    15. Added a second compiling function called pcre_compile2(). The only
2331        difference is that it has an extra argument, which is a pointer to an
2332        integer error code. When there is a compile-time failure, this is set
2333        non-zero, in addition to the error test pointer being set to point to an
2334        error message. The new argument may be NULL if no error number is required
2335        (but then you may as well call pcre_compile(), which is now just a
2336        wrapper). This facility is provided because some applications need a
2337        numeric error indication, but it has also enabled me to tidy up the way
2338        compile-time errors are handled in the POSIX wrapper.
2339    
2340    16. Added VPATH=.libs to the makefile; this should help when building with one
2341        prefix path and installing with another. (Or so I'm told by someone who
2342        knows more about this stuff than I do.)
2343    
2344    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2345        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2346        match everything, including newlines. This is not POSIX-compatible, but
2347        somebody wanted the feature. From pcretest it can be activated by using
2348        both the P and the s flags.
2349    
2350    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2351    
2352    19. libpcre.pc was being incorrectly installed as executable.
2353    
2354    20. A couple of places in pcretest check for end-of-line by looking for '\n';
2355        it now also looks for '\r' so that it will work unmodified on Windows.
2356    
2357    21. Added Google's contributed C++ wrapper to the distribution.
2358    
2359    22. Added some untidy missing memory free() calls in pcretest, to keep
2360        Electric Fence happy when testing.
2361    
2362    
2363    
2364    Version 5.0 13-Sep-04
2365    ---------------------
2366    
2367     1. Internal change: literal characters are no longer packed up into items
2368        containing multiple characters in a single byte-string. Each character
2369        is now matched using a separate opcode. However, there may be more than one
2370        byte in the character in UTF-8 mode.
2371    
2372     2. The pcre_callout_block structure has two new fields: pattern_position and
2373        next_item_length. These contain the offset in the pattern to the next match
2374        item, and its length, respectively.
2375    
2376     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2377        insertion of callouts before each pattern item. Added the /C option to
2378        pcretest to make use of this.
2379    
2380     4. On the advice of a Windows user, the lines
2381    
2382          #if defined(_WIN32) || defined(WIN32)
2383          _setmode( _fileno( stdout ), 0x8000 );
2384          #endif  /* defined(_WIN32) || defined(WIN32) */
2385    
2386        have been added to the source of pcretest. This apparently does useful
2387        magic in relation to line terminators.
2388    
2389     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2390        for the benefit of those environments where the "b" makes a difference.
2391    
2392     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2393        to know about it. I have put a hack into configure.in that adds in code
2394        to set GCC=yes if CC=icc. This seems to end up at a point in the
2395        generated configure script that is early enough to affect the setting of
2396        compiler options, which is what is needed, but I have no means of testing
2397        whether it really works. (The user who reported this had patched the
2398        generated configure script, which of course I cannot do.)
2399    
2400        LATER: After change 22 below (new libtool files), the configure script
2401        seems to know about icc (and also ecc). Therefore, I have commented out
2402        this hack in configure.in.
2403    
2404     7. Added support for pkg-config (2 patches were sent in).
2405    
2406     8. Negated POSIX character classes that used a combination of internal tables
2407        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2408        [[:^ascii]]. Typically, they would match almost any characters. The other
2409        POSIX classes were not broken in this way.
2410    
2411     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2412        to find the match, as PCRE was deluded into thinking that the match had to
2413        start at the start point or following a newline. The same bug applied to
2414        patterns with negative forward assertions or any backward assertions
2415        preceding ".*" at the start, unless the pattern required a fixed first
2416        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2417    
2418    10. In UTF-8 mode, when moving forwards in the subject after a failed match
2419        starting at the last subject character, bytes beyond the end of the subject
2420        string were read.
2421    
2422    11. Renamed the variable "class" as "classbits" to make life easier for C++
2423        users. (Previously there was a macro definition, but it apparently wasn't
2424        enough.)
2425    
2426    12. Added the new field "tables" to the extra data so that tables can be passed
2427        in at exec time, or the internal tables can be re-selected. This allows
2428        a compiled regex to be saved and re-used at a later time by a different
2429        program that might have everything at different addresses.
2430    
2431    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2432        -R library as well as a -L library.
2433    
2434    14. The debugging options of pcretest (-d on the command line or D on a
2435        pattern) showed incorrect output for anything following an extended class
2436        that contained multibyte characters and which was followed by a quantifier.
2437    
2438    15. Added optional support for general category Unicode character properties
2439        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2440        support. It adds about 90K to the size of the library. The meanings of the
2441        inbuilt class escapes such as \d and \s have NOT been changed.
2442    
2443    16. Updated pcredemo.c to include calls to free() to release the memory for the
2444        compiled pattern.
2445    
2446    17. The generated file chartables.c was being created in the source directory
2447        instead of in the building directory. This caused the build to fail if the
2448        source directory was different from the building directory, and was
2449        read-only.
2450    
2451    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2452        file. No doubt somebody will tell me if they don't make sense... Also added
2453        Dan Mooney's comments about building on OpenVMS.
2454    
2455    19. Added support for partial matching via the PCRE_PARTIAL option for
2456        pcre_exec() and the \P data escape in pcretest.
2457    
2458    20. Extended pcretest with 3 new pattern features:
2459    
2460        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2461              write the compiled pattern to the file whose name is "rest-of-line".
2462              This is a straight binary dump of the data, with the saved pointer to
2463              the character tables forced to be NULL. The study data, if any, is
2464              written too. After writing, pcretest reads a new pattern.
2465    
2466        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2467              compiled pattern from the given file. There must not be any
2468              occurrences of "<" in the file name (pretty unlikely); if there are,
2469              pcretest will instead treat the initial "<" as a pattern delimiter.
2470              After reading in the pattern, pcretest goes on to read data lines as
2471              usual.
2472    
2473        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2474              and 16-bit fields in a compiled pattern, to simulate a pattern that
2475              was compiled on a host of opposite endianness.
2476    
2477    21. The pcre-exec() function can now cope with patterns that were compiled on
2478        hosts of opposite endianness, with this restriction:
2479    
2480          As for any compiled expression that is saved and used later, the tables
2481          pointer field cannot be preserved; the extra_data field in the arguments
2482          to pcre_exec() should be used to pass in a tables address if a value
2483          other than the default internal tables were used at compile time.
2484    
2485    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2486        now diagnosed as an error. Previously, most of the time, a negative number
2487        would have been treated as zero, but if in addition "ovector" was passed as
2488        NULL, a crash could occur.
2489    
2490    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2491        new versions from the libtool 1.5 distribution (the last one is a copy of
2492        a file called libtool.m4). This seems to have fixed the need to patch
2493        "configure" to support Darwin 1.3 (which I used to do). However, I still
2494        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2495        workstation).
2496    
2497    24. Changed the PCRE licence to be the more standard "BSD" licence.
2498    
2499    
2500    Version 4.5 01-Dec-03
2501    ---------------------
2502    
2503     1. There has been some re-arrangement of the code for the match() function so
2504        that it can be compiled in a version that does not call itself recursively.
2505        Instead, it keeps those local variables that need separate instances for
2506        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2507        needs to "recurse". Keeping track of where control must go is done by means
2508        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2509        hide most of the details from the main code, and operates only if
2510        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2511        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2512        operating.
2513    
2514        To make it easier for callers to provide specially tailored get/free
2515        functions for this usage, two new functions, pcre_stack_malloc, and
2516        pcre_stack_free, are used. They are always called in strict stacking order,
2517        and the size of block requested is always the same.
2518    
2519        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2520        PCRE has been compiled to use the stack or the heap for recursion. The
2521        -C option of pcretest uses this to show which version is compiled.
2522    
2523        A new data escape \S, is added to pcretest; it causes the amounts of store
2524        obtained and freed by both kinds of malloc/free at match time to be added
2525        to the output.
2526    
2527     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2528        what's available on my current Linux desktop machine.
2529    
2530     3. When matching a UTF-8 string, the test for a valid string at the start has
2531        been extended. If start_offset is not zero, PCRE now checks that it points
2532        to a byte that is the start of a UTF-8 character. If not, it returns
2533        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2534        this is necessary because there may be backward assertions in the pattern.
2535        When matching the same subject several times, it may save resources to use
2536        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2537    
2538     4. The code for checking the validity of UTF-8 strings has been tightened so
2539        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2540        containing "overlong sequences".
2541    
2542     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2543        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2544        should have been "&", but it just so happened that all the cases this let
2545        through by mistake were picked up later in the function.
2546    
2547     6. I had used a variable called "isblank" - this is a C99 function, causing
2548        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2549    
2550     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2551        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2552        so the version is shown; (c) stop "make test" echoing "./RunTest".
2553    
2554     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2555    
2556     9. The prototype for memmove() for systems that don't have it was using
2557        size_t, but the inclusion of the header that defines size_t was later. I've
2558        moved the #includes for the C headers earlier to avoid this.
2559    
2560    10. Added some adjustments to the code to make it easier to compiler on certain
2561        special systems:
2562    
2563          (a) Some "const" qualifiers were missing.
2564          (b) Added the macro EXPORT before all exported functions; by default this
2565              is defined to be empty.
2566          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2567              that it reads its output file name as an argument instead of writing
2568              to the standard output and assuming this can be redirected.
2569    
2570    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2571        class containing characters with values greater than 255, PCRE compilation
2572        went into a loop.
2573    
2574    12. A recursive reference to a subpattern that was within another subpattern
2575        that had a minimum quantifier of zero caused PCRE to crash. For example,
2576        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2577        recursion. If the recursively-called subpattern itself had a zero repeat,
2578        that was OK.
2579    
2580    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2581        buffer into which it was copied (for escape processing) was still set at
2582        1024, so long lines caused crashes.
2583    
2584    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2585        "internal error: code overflow...". This applied to any character class
2586        that was followed by a possessive quantifier.
2587    
2588    15. Modified the Makefile to add libpcre.la as a prerequisite for
2589        libpcreposix.la because I was told this is needed for a parallel build to
2590        work.
2591    
2592    16. If a pattern that contained .* following optional items at the start was
2593        studied, the wrong optimizing data was generated, leading to matching
2594        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2595        matching string must start with a or b or c. The correct conclusion for
2596        this pattern is that a match can start with any character.
2597    
2598    
2599    Version 4.4 13-Aug-03
2600    ---------------------
2601    
2602     1. In UTF-8 mode, a character class containing characters with values between
2603        127 and 255 was not handled correctly if the compiled pattern was studied.
2604        In fixing this, I have also improved the studying algorithm for such
2605        classes (slightly).
2606    
2607     2. Three internal functions had redundant arguments passed to them. Removal
2608        might give a very teeny performance improvement.
2609    
2610     3. Documentation bug: the value of the capture_top field in a callout is *one
2611        more than* the number of the hightest numbered captured substring.
2612    
2613     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2614        in incorrectly linking with a previously installed version. They now link
2615        explicitly with libpcre.la.
2616    
2617     5. configure.in no longer needs to recognize Cygwin specially.
2618    
2619     6. A problem in pcre.in for Windows platforms is fixed.
2620    
2621     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2622        pcretest, it used to include the size of the study block as part of its
2623        output. Unfortunately, the structure contains a field that has a different
2624        size on different hardware architectures. This meant that the tests that
2625        showed this size failed. As the block is currently always of a fixed size,
2626        this information isn't actually particularly useful in pcretest output, so
2627        I have just removed it.
2628    
2629     8. Three pre-processor statements accidentally did not start in column 1.
2630        Sadly, there are *still* compilers around that complain, even though
2631        standard C has not required this for well over a decade. Sigh.
2632    
2633     9. In pcretest, the code for checking callouts passed small integers in the
2634        callout_data field, which is a void * field. However, some picky compilers
2635        complained about the casts involved for this on 64-bit systems. Now
2636        pcretest passes the address of the small integer instead, which should get
2637        rid of the warnings.
2638    
2639    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2640        both compile and run time, and gives an error if an invalid UTF-8 sequence
2641        is found. There is a option for disabling this check in cases where the
2642        string is known to be correct and/or the maximum performance is wanted.
2643    
2644    11. In response to a bug report, I changed one line in Makefile.in from
2645    
2646            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2647        to
2648            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2649    
2650        to look similar to other lines, but I have no way of telling whether this
2651        is the right thing to do, as I do not use Windows. No doubt I'll get told
2652        if it's wrong...
2653    
2654    
2655    Version 4.3 21-May-03
2656    ---------------------
2657    
2658    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2659       Makefile.
2660    
2661    2. Some refactoring to improve the quality of the code:
2662    
2663       (i)   The utf8_table... variables are now declared "const".
2664    
2665       (ii)  The code for \cx, which used the "case flipping" table to upper case
2666             lower case letters, now just substracts 32. This is ASCII-specific,
2667             but the whole concept of \cx is ASCII-specific, so it seems
2668             reasonable.
2669    
2670       (iii) PCRE was using its character types table to recognize decimal and
2671             hexadecimal digits in the pattern. This is silly, because it handles
2672             only 0-9, a-f, and A-F, but the character types table is locale-
2673             specific, which means strange things might happen. A private
2674             table is now used for this - though it costs 256 bytes, a table is
2675             much faster than multiple explicit tests. Of course, the standard
2676             character types table is still used for matching digits in subject
2677             strings against \d.
2678    
2679       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2680             ending in _t are). So I've renamed it as ESC_tee.
2681    
2682    3. The first argument for regexec() in the POSIX wrapper should have been
2683       defined as "const".
2684    
2685    4. Changed pcretest to use malloc() for its buffers so that they can be
2686       Electric Fenced for debugging.
2687    
2688    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2689       to read one or more bytes before the start of the subject string. Often this
2690       had no effect on PCRE's behaviour, but in some circumstances it could
2691       provoke a segmentation fault.
2692    
2693    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2694       to try to read one or more bytes before the start of the subject string.
2695    
2696    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2697       UTF-8 support could misbehave in various ways if the subject string
2698       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2699       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2700       back over UTF-8 characters.)
2701    
2702    
2703    Version 4.2 14-Apr-03
2704    ---------------------
2705    
2706    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2707    
2708    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2709         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2710         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2711         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2712         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2713           and BUILD_EXEEXT
2714         Note: automatic setting of the BUILD variables is not yet working
2715         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2716           compile-time but not at link-time
2717         [LINK]: use for linking executables only
2718         make different versions for Windows and non-Windows
2719         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2720           libraries
2721         [LINK_FOR_BUILD]: new variable
2722         [OBJEXT]: use throughout
2723         [EXEEXT]: use throughout
2724         <winshared>: new target
2725         <wininstall>: new target
2726         <dftables.o>: use native compiler
2727         <dftables>: use native linker
2728         <install>: handle Windows platform correctly
2729         <clean>: ditto
2730         <check>: ditto
2731         copy DLL to top builddir before testing
2732    
2733       As part of these changes, -no-undefined was removed again. This was reported
2734       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2735       in any case.
2736    
2737    3. Some tidies to get rid of compiler warnings:
2738    
2739       . In the match_data structure, match_limit was an unsigned long int, whereas
2740         match_call_count was an int. I've made them both unsigned long ints.
2741    
2742       . In pcretest the fact that a const uschar * doesn't automatically cast to
2743         a void * provoked a warning.
2744    
2745       . Turning on some more compiler warnings threw up some "shadow" variables
2746         and a few more missing casts.
2747    
2748    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2749       option, a class that contained a single character with a value between 128
2750       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2751    
2752    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2753       option, a class that contained several characters, but with at least one
2754       whose value was between 128 and 255 caused PCRE to crash.
2755    
2756    
2757    Version 4.1 12-Mar-03
2758    ---------------------
2759    
2760    1. Compiling with gcc -pedantic found a couple of places where casts were
2761    needed, and a string in dftables.c that was longer than standard compilers are
2762    required to support.
2763    
2764    2. Compiling with Sun's compiler found a few more places where the code could
2765    be tidied up in order to avoid warnings.
2766    
2767    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2768    first of these names is deprecated in the latest Autoconf in favour of the name
2769    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2770    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2771    analogy I have changed it to CFLAGS_FOR_BUILD.
2772    
2773    4. Added -no-undefined to the linking command in the Makefile, because this is
2774    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2775    linking step for the pcreposix library.
2776    
2777    5. PCRE was failing to diagnose the case of two named groups with the same
2778    name.
2779    
2780    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2781    literal character that is needed in the subject for a match, and scans along to
2782    ensure that it is present before embarking on the full matching process. This
2783    saves time in cases of nested unlimited repeats that are never going to match.
2784    Problem: the scan can take a lot of time if the subject is very long (e.g.
2785    megabytes), thus penalizing straightforward matches. It is now done only if the
2786    amount of subject to be scanned is less than 1000 bytes.
2787    
2788    7. A lesser problem with the same optimization is that it was recording the
2789    first character of an anchored pattern as "needed", thus provoking a search
2790    right along the subject, even when the first match of the pattern was going to
2791    fail. The "needed" character is now not set for anchored patterns, unless it
2792    follows something in the pattern that is of non-fixed length. Thus, it still
2793    fulfils its original purpose of finding quick non-matches in cases of nested
2794    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2795    
2796    
2797    Version 4.0 17-Feb-03
2798    ---------------------
2799    
2800    1. If a comment in an extended regex that started immediately after a meta-item
2801    extended to the end of string, PCRE compiled incorrect data. This could lead to
2802    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2803    
2804    2. Moved to autoconf 2.53 and libtool 1.4.2.
2805    
2806    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2807    the special perltest8 script is no longer needed - all the tests can be run
2808    from a single perltest script.
2809    
2810    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2811    by \s. It has now been removed in PCRE. This means it isn't recognized as
2812    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2813    class [:space:] *does* include VT, thereby creating a mess.
2814    
2815    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2816    space and tab.
2817    
2818    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2819    its new features into the main test script, reducing the number of scripts.
2820    
2821    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2822    were backward compatible, and made the (?i) apply to the whole pattern, as if
2823    /i were given. Now it behaves more logically, and applies the option setting
2824    only to what follows. PCRE has been changed to follow suit. However, if it
2825    finds options settings right at the start of the pattern, it extracts them into
2826    the global options, as before. Thus, they show up in the info data.
2827    
2828    8. Added support for the \Q...\E escape sequence. Characters in between are
2829    treated as literals. This is slightly different from Perl in that $ and @ are
2830    also handled as literals inside the quotes. In Perl, they will cause variable
2831    interpolation. Note the following examples:
2832    
2833        Pattern            PCRE matches      Perl matches
2834    
2835        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
2836        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
2837        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
2838    
2839    For compatibility with Perl, \Q...\E sequences are recognized inside character
2840    classes as well as outside them.
2841    
2842    9. Re-organized 3 code statements in pcretest to avoid "overflow in
2843    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2844    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2845    signed/unsigned warnings.
2846    
2847    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2848    option for pcretest, so I've replaced it by a simple function that does just
2849    that job.
2850    
2851    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2852    "pcregrep -".
2853    
2854    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2855    Java package. This provides some syntactic sugar for simple cases of what my
2856    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2857    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2858    item, you can use this simplified notation. Note that only makes sense with
2859    greedy quantifiers. Consequently, the use of the possessive quantifier forces
2860    greediness, whatever the setting of the PCRE_UNGREEDY option.
2861    
2862    13. A change of greediness default within a pattern was not taking effect at
2863    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2864    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2865    was abstracted outside.
2866    
2867    14. PCRE now supports the \G assertion. It is true when the current matching
2868    position is at the start point of the match. This differs from \A when the
2869    starting offset is non-zero. Used with the /g option of pcretest (or similar
2870    code), it works in the same way as it does for Perl's /g option. If all
2871    alternatives of a regex begin with \G, the expression is anchored to the start
2872    match position, and the "anchored" flag is set in the compiled expression.
2873    
2874    15. Some bugs concerning the handling of certain option changes within patterns
2875    have been fixed. These applied to options other than (?ims). For example,
2876    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2877    been the other way round. Some of this was related to change 7 above.
2878    
2879    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2880    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2881    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2882    POSIX classes only within a class (e.g. /[[:alpha:]]/).
2883    
2884    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2885    mode. Unlike ".", it always matches newline, whatever the setting of
2886    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2887    assertions. Perl allows it, but it doesn't (in general) work because it can't
2888    calculate the length of the lookbehind. At least, that's the case for Perl
2889    5.8.0 - I've been told they are going to document that it doesn't work in
2890    future.
2891    
2892    18. Added an error diagnosis for escapes that PCRE does not support: these are
2893    \L, \l, \N, \P, \p, \U, \u, and \X.
2894    
2895    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2896    reading past the end of the pattern in cases such as /[abcd/.
2897    
2898    20. PCRE was getting more memory than necessary for patterns with classes that
2899    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2900    
2901    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2902    compiling PCRE for use with Virtual Pascal.
2903    
2904    22. Small fix to the Makefile to make it work properly if the build is done
2905    outside the source tree.
2906    
2907    23. Added a new extension: a condition to go with recursion. If a conditional
2908    subpattern starts with (?(R) the "true" branch is used if recursion has
2909    happened, whereas the "false" branch is used only at the top level.
2910    
2911    24. When there was a very long string of literal characters (over 255 bytes
2912    without UTF support, over 250 bytes with UTF support), the computation of how
2913    much memory was required could be incorrect, leading to segfaults or other
2914    strange effects.
2915    
2916    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2917    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2918    there was a subsequent back reference to those brackets. This meant that, for
2919    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2920    possible to check for precisely this case. All we can do is abandon the
2921    optimization if .* occurs inside capturing brackets when there are any back
2922    references whatsoever. (See below for a better fix that came later.)
2923    
2924    26. The handling of the optimization for finding the first character of a
2925    non-anchored pattern, and for finding a character that is required later in the
2926    match were failing in some cases. This didn't break the matching; it just
2927    failed to optimize when it could. The way this is done has been re-implemented.
2928    
2929    27. Fixed typo in error message for invalid (?R item (it said "(?p").
2930    
2931    28. Added a new feature that provides some of the functionality that Perl
2932    provides with (?{...}). The facility is termed a "callout". The way it is done
2933    in PCRE is for the caller to provide an optional function, by setting
2934    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2935    global variable. By default it is unset, which disables all calling out. To get
2936    the function called, the regex must include (?C) at appropriate points. This
2937    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2938    This provides a means of identifying different callout points. When PCRE
2939    reaches such a point in the regex, if pcre_callout has been set, the external
2940    function is called. It is provided with data in a structure called
2941    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2942    matching continues; if it returns a non-zero value, the match at the current
2943    point fails. However, backtracking will occur if possible. [This was changed
2944    later and other features added - see item 49 below.]
2945    
2946    29. pcretest is upgraded to test the callout functionality. It provides a
2947    callout function that displays information. By default, it shows the start of
2948    the match and the current position in the text. There are some new data escapes
2949    to vary what happens:
2950    
2951        \C+         in addition, show current contents of captured substrings
2952        \C-         do not supply a callout function
2953        \C!n        return 1 when callout number n is reached
2954        \C!n!m      return 1 when callout number n is reached for the mth time
2955    
2956    30. If pcregrep was called with the -l option and just a single file name, it
2957    output "<stdin>" if a match was found, instead of the file name.
2958    
2959    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2960    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2961    pcre_exec(). This saves a malloc/free per call. The default value of
2962    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2963    when configuring.
2964    
2965    32. The default maximum size of a compiled pattern is 64K. There have been a
2966    few cases of people hitting this limit. The code now uses macros to handle the
2967    storing of links as offsets within the compiled pattern. It defaults to 2-byte
2968    links, but this can be changed to 3 or 4 bytes by --with-link-size when
2969    configuring. Tests 2 and 5 work only with 2-byte links because they output
2970    debugging information about compiled patterns.
2971    
2972    33. Internal code re-arrangements:
2973    
2974    (a) Moved the debugging function for printing out a compiled regex into
2975        its own source file (printint.c) and used #include to pull it into
2976        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2977        separate copies.
2978    
2979    (b) Defined the list of op-code names for debugging as a macro in
2980        internal.h so that it is next to the definition of the opcodes.
2981    
2982    (c) Defined a table of op-code lengths for simpler skipping along compiled
2983        code. This is again a macro in internal.h so that it is next to the
2984        definition of the opcodes.
2985    
2986    34. Added support for recursive calls to individual subpatterns, along the
2987    lines of Robin Houston's patch (but implemented somewhat differently).
2988    
2989    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2990    allow it to read and process whole directories in Win32. This code was
2991    contributed by Lionel Fourquaux; it has not been tested by me.
2992    
2993    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2994    used to name a group. Names consist of alphanumerics and underscores, and must
2995    be unique. Back references use the syntax (?P=name) and recursive calls use
2996    (?P>name) which is a PCRE extension to the Python extension. Groups still have
2997    numbers. The function pcre_fullinfo() can be used after compilation to extract
2998    a name/number map. There are three relevant calls:
2999    
3000      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
3001      PCRE_INFO_NAMECOUNT            yields the number of entries
3002      PCRE_INFO_NAMETABLE            yields a pointer to the map.
3003    
3004    The map is a vector of fixed-size entries. The size of each entry depends on
3005    the length of the longest name used. The first two bytes of each entry are the
3006    group number, most significant byte first. There follows the corresponding
3007    name, zero terminated. The names are in alphabetical order.
3008    
3009    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3010    case instead of 255. Making it the same both with and without UTF-8 support
3011    means that the same test output works with both.
3012    
3013    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3014    calling malloc() with a zero argument.
3015    
3016    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3017    optimization. I've improved things by keeping a bitmap of backreferences with
3018    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3019    fact referenced, the optimization can be applied. It is unlikely that a
3020    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3021    the match to follow \n) will appear inside brackets with a number greater than
3022    31, but if it does, any back reference > 31 suppresses the optimization.
3023    
3024    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3025    of disabling numbered capturing parentheses. Any opening parenthesis that is
3026    not followed by ? behaves as if it were followed by ?: but named parentheses
3027    can still be used for capturing (and they will acquire numbers in the usual
3028    way).
3029    
3030    41. Redesigned the return codes from the match() function into yes/no/error so
3031    that errors can be passed back from deep inside the nested calls. A malloc
3032    failure while inside a recursive subpattern call now causes the
3033    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3034    
3035    42. It is now possible to set a limit on the number of times the match()
3036    function is called in a call to pcre_exec(). This facility makes it possible to
3037    limit the amount of recursion and backtracking, though not in a directly
3038    obvious way, because the match() function is used in a number of different
3039    circumstances. The count starts from zero for each position in the subject
3040    string (for non-anchored patterns). The default limit is, for compatibility, a
3041    large number, namely 10 000 000. You can change this in two ways:
3042    
3043    (a) When configuring PCRE before making, you can use --with-match-limit=n
3044        to set a default value for the compiled library.
3045    
3046    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3047        a different value is set. See 45 below.
3048    
3049    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3050    
3051    43. Added a new function pcre_config(int, void *) to enable run-time extraction
3052    of things that can be changed at compile time. The first argument specifies
3053    what is wanted and the second points to where the information is to be placed.
3054    The current list of available information is:
3055    
3056      PCRE_CONFIG_UTF8
3057    
3058    The output is an integer that is set to one if UTF-8 support is available;
3059    otherwise it is set to zero.
3060    
3061      PCRE_CONFIG_NEWLINE
3062    
3063    The output is an integer that it set to the value of the code that is used for
3064    newline. It is either LF (10) or CR (13).
3065    
3066      PCRE_CONFIG_LINK_SIZE
3067    
3068    The output is an integer that contains the number of bytes used for internal
3069    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3070    
3071      PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3072    
3073    The output is an integer that contains the threshold above which the POSIX
3074    interface uses malloc() for output vectors. See item 31 above.
3075    
3076      PCRE_CONFIG_MATCH_LIMIT
3077    
3078    The output is an unsigned integer that contains the default limit of the number
3079    of match() calls in a pcre_exec() execution. See 42 above.
3080    
3081    44. pcretest has been upgraded by the addition of the -C option. This causes it
3082    to extract all the available output from the new pcre_config() function, and to
3083    output it. The program then exits immediately.
3084    
3085    45. A need has arisen to pass over additional data with calls to pcre_exec() in
3086    order to support additional features. One way would have been to define
3087    pcre_exec2() (for example) with extra arguments, but this would not have been
3088    extensible, and would also have required all calls to the original function to
3089    be mapped to the new one. Instead, I have chosen to extend the mechanism that
3090    is used for passing in "extra" data from pcre_study().
3091    
3092    The pcre_extra structure is now exposed and defined in pcre.h. It currently
3093    contains the following fields:
3094    
3095      flags         a bitmap indicating which of the following fields are set
3096      study_data    opaque data from pcre_study()
3097      match_limit   a way of specifying a limit on match() calls for a specific
3098                      call to pcre_exec()
3099      callout_data  data for callouts (see 49 below)
3100    
3101    The flag bits are also defined in pcre.h, and are
3102    
3103      PCRE_EXTRA_STUDY_DATA
3104      PCRE_EXTRA_MATCH_LIMIT
3105      PCRE_EXTRA_CALLOUT_DATA
3106    
3107    The pcre_study() function now returns one of these new pcre_extra blocks, with
3108    the actual study data pointed to by the study_data field, and the
3109    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3110    before. That is, this change is entirely upwards-compatible and requires no
3111    change to existing code.
3112    
3113    If you want to pass in additional data to pcre_exec(), you can either place it
3114    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3115    block.
3116    
3117    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3118    data string contains the escape sequence \M, pcretest calls pcre_exec() several
3119    times with different match limits, until it finds the minimum value needed for
3120    pcre_exec() to complete. The value is then output. This can be instructive; for
3121    most simple matches the number is quite small, but for pathological cases it
3122    gets very large very quickly.
3123    
3124    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3125    returns the size of the data block pointed to by the study_data field in a
3126    pcre_extra block, that is, the value that was passed as the argument to
3127    pcre_malloc() when PCRE was getting memory in which to place the information
3128    created by pcre_study(). The fourth argument should point to a size_t variable.
3129    pcretest has been extended so that this information is shown after a successful
3130    pcre_study() call when information about the compiled regex is being displayed.
3131    
3132    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3133    because what follows is always an absolute path. (Later: it turns out that this
3134    is more than cosmetic for MinGW, because it doesn't like empty path
3135    components.)
3136    
3137    49. Some changes have been made to the callout feature (see 28 above):
3138    
3139    (i)  A callout function now has three choices for what it returns:
3140    
3141           0  =>  success, carry on matching
3142         > 0  =>  failure at this point, but backtrack if possible
3143         < 0  =>  serious error, return this value from pcre_exec()
3144    
3145         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3146         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3147         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3148         use by callout functions. It will never be used by PCRE itself.
3149    
3150    (ii) The pcre_extra structure (see 45 above) has a void * field called
3151         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3152         pcre_callout_block structure has a field of the same name. The contents of
3153         the field passed in the pcre_extra structure are passed to the callout
3154         function in the corresponding field in the callout block. This makes it
3155         easier to use the same callout-containing regex from multiple threads. For
3156         testing, the pcretest program has a new data escape
3157    
3158           \C*n        pass the number n (may be negative) as callout_data
3159    
3160         If the callout function in pcretest receives a non-zero value as
3161         callout_data, it returns that value.
3162    
3163    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3164    there were some redundant $(CFLAGS) in commands that are now specified as
3165    $(LINK), which already includes $(CFLAGS).
3166    
3167    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3168    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3169    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3170    one-byte characters throughout. Note that case-insensitive matching applies
3171    only to characters whose values are less than 256. PCRE doesn't support the
3172    notion of cases for higher-valued characters.
3173    
3174    (i)   A character class whose characters are all within 0-255 is handled as
3175          a bit map, and the map is inverted for negative classes. Previously, a
3176          character > 255 always failed to match such a class; however it should
3177          match if the class was a negative one (e.g. [^ab]). This has been fixed.
3178    
3179    (ii)  A negated character class with a single character < 255 is coded as
3180          "not this character" (OP_NOT). This wasn't working properly when the test
3181          character was multibyte, either singly or repeated.
3182    
3183    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3184          mode, for example: \x{100}{2,3}.
3185    
3186    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3187          singly or repeated) now correctly test multibyte characters. However,
3188          PCRE doesn't recognize any characters with values greater than 255 as
3189          digits, spaces, or word characters. Such characters always match \D, \S,
3190          and \W, and never match \d, \s, or \w.
3191    
3192    (v)   Classes may now contain characters and character ranges with values
3193          greater than 255. For example: [ab\x{100}-\x{400}].
3194    
3195    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
3196          PCRE in UTF-8 mode.
3197    
3198    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3199    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3200    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3201    value.)
3202    
3203    53. The single man page has become too large. I have therefore split it up into
3204    a number of separate man pages. These also give rise to individual HTML pages;
3205    these are now put in a separate directory, and there is an index.html page that
3206    lists them all. Some hyperlinking between the pages has been installed.
3207    
3208    54. Added convenience functions for handling named capturing parentheses.
3209    
3210    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3211    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3212    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3213    are faulted.
3214    
3215    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3216    calling configure. These values are used when compiling the dftables.c program
3217    which is run to generate the source of the default character tables. They
3218    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3219    you will need to set these values.
3220    
3221    57. Updated the building process for Windows DLL, as provided by Fred Cox.
3222    
3223    
3224    Version 3.9 02-Jan-02
3225    ---------------------
3226    
3227    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3228    
3229    2. If --disable-static was given, the building process failed when trying to
3230    build pcretest and pcregrep. (For some reason it was using libtool to compile
3231    them, which is not right, as they aren't part of the library.)
3232    
3233    
3234    Version 3.8 18-Dec-01
3235    ---------------------
3236    
3237    1. The experimental UTF-8 code was completely screwed up. It was packing the
3238    bytes in the wrong order. How dumb can you get?
3239    
3240    
3241    Version 3.7 29-Oct-01
3242    ---------------------
3243    
3244    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3245    This caused pcretest, when used on the test data, to segfault. Unfortunately,
3246    this didn't happen under Solaris 8, where I normally test things.
3247    
3248    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3249    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3250    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3251    this fix an hour or so after the initial 3.7 release.)
3252    
3253    
3254    Version 3.6 23-Oct-01
3255    ---------------------
3256    
3257    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3258    offsets passed as NULL with zero offset count.
3259    
3260    2. The config.guess and config.sub files had not been updated when I moved to
3261    the latest autoconf.
3262    
3263    
3264    Version 3.5 15-Aug-01
3265    ---------------------
3266    
3267    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3268    had been forgotten.
3269    
3270    2. By using declared but undefined structures, we can avoid using "void"
3271    definitions in pcre.h while keeping the internal definitions of the structures
3272    private.
3273    
3274    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3275    user point of view, this means that both static and shared libraries are built
3276    by default, but this can be individually controlled. More of the work of
3277    handling this static/shared cases is now inside libtool instead of PCRE's make
3278    file.
3279    
3280    4. The pcretest utility is now installed along with pcregrep because it is
3281    useful for users (to test regexs) and by doing this, it automatically gets
3282    relinked by libtool. The documentation has been turned into a man page, so
3283    there are now .1, .txt, and .html versions in /doc.
3284    
3285    5. Upgrades to pcregrep:
3286       (i)   Added long-form option names like gnu grep.
3287       (ii)  Added --help to list all options with an explanatory phrase.
3288       (iii) Added -r, --recursive to recurse into sub-directories.
3289       (iv)  Added -f, --file to read patterns from a file.
3290    
3291    6. pcre_exec() was referring to its "code" argument before testing that
3292    argument for NULL (and giving an error if it was NULL).
3293    
3294    7. Upgraded Makefile.in to allow for compiling in a different directory from
3295    the source directory.
3296    
3297    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3298    options bits, the pointer it was passed was to an int instead of to an unsigned
3299    long int. This mattered only on 64-bit systems.
3300    
3301    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3302    generated) instead of pcre.in, which it its source. Also made the same change
3303    in several of the .c files.
3304    
3305    10. A new release of gcc defines printf() as a macro, which broke pcretest
3306    because it had an ifdef in the middle of a string argument for printf(). Fixed
3307    by using separate calls to printf().
3308    
3309    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3310    script, to force use of CR or LF instead of \n in the source. On non-Unix
3311    systems, the value can be set in config.h.
3312    
3313    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3314    absolute limit. Changed the text of the error message to make this clear, and
3315    likewise updated the man page.
3316    
3317    13. The limit of 99 on the number of capturing subpatterns has been removed.
3318    The new limit is 65535, which I hope will not be a "real" limit.
3319    
3320    
3321    Version 3.4 22-Aug-00
3322    ---------------------
3323    
3324    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3325    
3326    2. Diagnose condition (?(0) as an error instead of crashing on matching.
3327    
3328    
3329    Version 3.3 01-Aug-00
3330    ---------------------
3331    
3332    1. If an octal character was given, but the value was greater than \377, it
3333    was not getting masked to the least significant bits, as documented. This could
3334    lead to crashes in some systems.
3335    
3336    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3337    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3338    
3339    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3340    These just pass their arguments on to (pcre_free)(), but they are provided
3341    because some uses of PCRE bind it to non-C systems that can call its functions,
3342    but cannot call free() or pcre_free() directly.
3343    
3344    4. Add "make test" as a synonym for "make check". Corrected some comments in
3345    the Makefile.
3346    
3347    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3348    Makefile.
3349    
3350    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3351    command called pgrep for grepping around the active processes.
3352    
3353    7. Added the beginnings of support for UTF-8 character strings.
3354    
3355    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3356    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3357    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3358    out for the ar command.)
3359    
3360    
3361    Version 3.2 12-May-00
3362    ---------------------
3363    
3364    This is purely a bug fixing release.
3365    
3366    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3367    of ZA. This was just one example of several cases that could provoke this bug,
3368    which was introduced by change 9 of version 2.00. The code for breaking
3369    infinite loops after an iteration that matches an empty string was't working
3370    correctly.
3371    
3372    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3373    when matched against abbab (for example). After matching an empty string, it
3374    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3375    caused it to match further down the string than it should.
3376    
3377    3. The code contained an inclusion of sys/types.h. It isn't clear why this
3378    was there because it doesn't seem to be needed, and it causes trouble on some
3379    systems, as it is not a Standard C header. It has been removed.
3380    
3381    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3382    were reported on the Macintosh. The changes were from
3383    
3384      while ((c = *(++ptr)) != 0 && c != '\n');
3385    to
3386      while ((c = *(++ptr)) != 0 && c != '\n') ;
3387    
3388    Totally extraordinary, but if that's what it takes...
3389    
3390    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3391    available. Added HAVE_BCOPY and an autoconf test for it; if neither
3392    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3393    assumes the way PCRE uses memmove() (always moving upwards).
3394    
3395    6. PCRE is being used in one environment where strchr() is not available. There
3396    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3397    faster code anyway.
3398    
3399    
3400    Version 3.1 09-Feb-00
3401    ---------------------
3402    
3403    The only change in this release is the fixing of some bugs in Makefile.in for
3404    the "install" target:
3405    
3406    (1) It was failing to install pcreposix.h.
3407    
3408    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3409    
3410    
3411  Version 3.0 01-Feb-00  Version 3.0 01-Feb-00
3412  ---------------------  ---------------------

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