ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 49 by nigel, Sat Feb 24 21:39:33 2007 UTC revision 442 by ph10, Fri Sep 11 10:21:02 2009 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 8.00 ??-???-??
5    ----------------------
7    1.  The table for translating pcre_compile() error codes into POSIX error codes
8        was out-of-date, and there was no check on the pcre_compile() error code
9        being within the table. This could lead to an OK return being given in
10        error.
12    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
13        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14        in a Windows environment.
16    3.  The pcregrep --count option prints the count for each file even when it is
17        zero, as does GNU grep. However, pcregrep was also printing all files when
18        --files-with-matches was added. Now, when both options are given, it prints
19        counts only for those files that have at least one match. (GNU grep just
20        prints the file name in this circumstance, but including the count seems
21        more useful - otherwise, why use --count?) Also ensured that the
22        combination -clh just lists non-zero counts, with no names.
24    4.  The long form of the pcregrep -F option was incorrectly implemented as
25        --fixed_strings instead of --fixed-strings. This is an incompatible change,
26        but it seems right to fix it, and I didn't think it was worth preserving
27        the old behaviour.
29    5.  The command line items --regex=pattern and --regexp=pattern were not
30        recognized by pcregrep, which required --regex pattern or --regexp pattern
31        (with a space rather than an '='). The man page documented the '=' forms,
32        which are compatible with GNU grep; these now work.
34    6.  No libpcreposix.pc file was created for pkg-config; there was just
35        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
37    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
38        when UCP support is not needed, by modifying the Python script that
39        generates it from Unicode data files. This should not matter if the module
40        is correctly used as a library, but I received one complaint about 50K of
41        unwanted data. My guess is that the person linked everything into his
42        program rather than using a library. Anyway, it does no harm.
44    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
45        was a minimum greater than 1 for a wide character in a possessive
46        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
47        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
48        character. Chaos in the form of incorrect output or a compiling loop could
49        result.
51    9.  The restrictions on what a pattern can contain when partial matching is
52        requested for pcre_exec() have been removed. All patterns can now be
53        partially matched by this function. In addition, if there are at least two
54        slots in the offset vector, the offset of the earliest inspected character
55        for the match and the offset of the end of the subject are set in them when
56        PCRE_ERROR_PARTIAL is returned.
58    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
59        synonymous with PCRE_PARTIAL, for backwards compatibility, and
60        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
61        and may be more useful for multi-segment matching, especially with
62        pcre_exec().
64    11. Partial matching with pcre_exec() is now more intuitive. A partial match
65        used to be given if ever the end of the subject was reached; now it is
66        given only if matching could not proceed because another character was
67        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
68        string "Z", which now yields "no match" instead of "partial match". In the
69        case of pcre_dfa_exec(), "no match" is given if every matching path for the
70        final character ended with (*FAIL).
72    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
73        if the pattern had a "must contain" character that was already found in the
74        earlier partial match, unless partial matching was again requested. For
75        example, with the pattern /dog.(body)?/, the "must contain" character is
76        "g". If the first part-match was for the string "dog", restarting with
77        "sbody" failed. This bug has been fixed.
79    13. The string returned by pcre_dfa_exec() after a partial match has been
80        changed so that it starts at the first inspected character rather than the
81        first character of the match. This makes a difference only if the pattern
82        starts with a lookbehind assertion or \b or \B (\K is not supported by
83        pcre_dfa_exec()). It's an incompatible change, but it makes the two
84        matching functions compatible, and I think it's the right thing to do.
86    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
87        so that the demonstration program is easily available in environments where
88        PCRE has not been installed from source.
90    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
91        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
92        library.
94    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
95        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
96        is not the first non-POSIX option to be added. Clearly some people find
97        these options useful.
99    17. If a caller to the POSIX matching function regexec() passes a non-zero
100        value for nmatch with a NULL value for pmatch, the value of
101        nmatch is forced to zero.
103    18. RunGrepTest did not have a test for the availability of the -u option of
104        the diff command, as RunTest does. It now checks in the same way as
105        RunTest, and also checks for the -b option.
107    19. If an odd number of negated classes containing just a single character
108        interposed, within parentheses, between a forward reference to a named
109        subpattern and the definition of the subpattern, compilation crashed with
110        an internal error, complaining that it could not find the referenced
111        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
112        [The bug was that it was starting one character too far in when skipping
113        over the character class, thus treating the ] as data rather than
114        terminating the class. This meant it could skip too much.]
116    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
117        /g option in pcretest when the pattern contains \K, which makes it possible
118        to have an empty string match not at the start, even when the pattern is
119        anchored. Updated pcretest and pcredemo to use this option.
122    Version 7.9 11-Apr-09
123    ---------------------
125    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
126        (pcretest), all targets were linked against these libraries. This included
127        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
128        libraries. This caused unwanted dependencies to be created. This problem
129        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
130        pcretest is linked with readline.
132    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
133        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
134        moved outside it again, because FALSE and TRUE are already defined in AIX,
135        but BOOL is not.
137    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
138        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
140    4.  The pcregrep documentation said spaces were inserted as well as colons (or
141        hyphens) following file names and line numbers when outputting matching
142        lines. This is not true; no spaces are inserted. I have also clarified the
143        wording for the --colour (or --color) option.
145    5.  In pcregrep, when --colour was used with -o, the list of matching strings
146        was not coloured; this is different to GNU grep, so I have changed it to be
147        the same.
149    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
150        each matching line was coloured. Now it goes on to look for further matches
151        of any of the test patterns, which is the same behaviour as GNU grep.
153    7.  A pattern that could match an empty string could cause pcregrep to loop; it
154        doesn't make sense to accept an empty string match in pcregrep, so I have
155        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
156        seems to be how GNU grep behaves.
158    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
159        start or after a newline", because the conditional assertion was not being
160        correctly handled. The rule now is that both the assertion and what follows
161        in the first alternative must satisfy the test.
163    9.  If auto-callout was enabled in a pattern with a conditional group whose
164        condition was an assertion, PCRE could crash during matching, both with
165        pcre_exec() and pcre_dfa_exec().
167    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
168        used for matching.
170    11. Unicode property support in character classes was not working for
171        characters (bytes) greater than 127 when not in UTF-8 mode.
173    12. Added the -M command line option to pcretest.
175    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
177    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
179    16. Added comments and documentation about mis-use of no_arg in the C++
180        wrapper.
182    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
183        from Martin Jerabek that uses macro names for all relevant character and
184        string constants.
186    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
187        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
188        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
189        these, but not everybody uses configure.
191    19. A conditional group that had only one branch was not being correctly
192        recognized as an item that could match an empty string. This meant that an
193        enclosing group might also not be so recognized, causing infinite looping
194        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
195        with the subject "ab", where knowledge that the repeated group can match
196        nothing is needed in order to break the loop.
198    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
199        exec(), but without supplying a callout function, matching went wrong.
201    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
202        leak if the size of the offset vector was greater than 30. When the vector
203        is smaller, the saved offsets during recursion go onto a local stack
204        vector, but for larger vectors malloc() is used. It was failing to free
205        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
206        error, in fact).
208    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
209        heapframe that is used only when UTF-8 support is enabled. This caused no
210        problem, but was untidy.
212    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
213        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
214        included within another project.
216    24. Steven Van Ingelgem's patches to add more options to the CMake support,
217        slightly modified by me:
219          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
220              not building pcregrep.
222          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
223              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
225    25. Forward references, both numeric and by name, in patterns that made use of
226        duplicate group numbers, could behave incorrectly or give incorrect errors,
227        because when scanning forward to find the reference group, PCRE was not
228        taking into account the duplicate group numbers. A pattern such as
229        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
231    26. Changed a few more instances of "const unsigned char *" to USPTR, making
232        the feature of a custom pointer more persuasive (as requested by a user).
234    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
235        pcretest.c, inside #ifndefs, because it seems they are sometimes already
236        pre-defined.
238    28. Added support for (*UTF8) at the start of a pattern.
240    29. Arrange for flags added by the "release type" setting in CMake to be shown
241        in the configuration summary.
244    Version 7.8 05-Sep-08
245    ---------------------
247    1.  Replaced UCP searching code with optimized version as implemented for Ad
248        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
249        stage table and inline lookup instead of a function, giving speed ups of 2
250        to 5 times on some simple patterns that I tested. Permission was given to
251        distribute the MultiStage2.py script that generates the tables (it's not in
252        the tarball, but is in the Subversion repository).
254    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
255        scripts.
257    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
258        a group with a zero qualifier. The result of the study could be incorrect,
259        or the function might crash, depending on the pattern.
261    4.  Caseless matching was not working for non-ASCII characters in back
262        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
263        It now works when Unicode Property Support is available.
265    5.  In pcretest, an escape such as \x{de} in the data was always generating
266        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
267        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
268        truncation.
270    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
272    7.  Added two (int) casts to pcregrep when printing the difference of two
273        pointers, in case they are 64-bit values.
275    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
276        test 2 if it fails.
278    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
279        and a #define of that name to empty if it is not externally set. This is to
280        allow users of MSVC to set it if necessary.
282    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
283        the convenience functions in the pcre_get.c source file.
285    11. An option change at the start of a pattern that had top-level alternatives
286        could cause overwriting and/or a crash. This command provoked a crash in
287        some environments:
289          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
291        This potential security problem was recorded as CVE-2008-2371.
293    12. For a pattern where the match had to start at the beginning or immediately
294        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
295        pcre_dfa_exec() could read past the end of the passed subject if there was
296        no match. To help with detecting such bugs (e.g. with valgrind), I modified
297        pcretest so that it places the subject at the end of its malloc-ed buffer.
299    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
300        exec() might read past the end of the data buffer in UTF-8 mode.
302    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
303        the data contained the byte 0x85 as part of a UTF-8 character within its
304        first line. This applied both to normal and DFA matching.
306    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
307        /^[^d]*?$/8 failed to match "abc".
309    16. Added a missing copyright notice to pcrecpp_internal.h.
311    17. Make it more clear in the documentation that values returned from
312        pcre_exec() in ovector are byte offsets, not character counts.
314    18. Tidied a few places to stop certain compilers from issuing warnings.
316    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
317        supplied by Stefan Weber. I made a further small update for 7.8 because
318        there is a change of source arrangements: the pcre_searchfuncs.c module is
319        replaced by pcre_ucd.c.
322    Version 7.7 07-May-08
323    ---------------------
325    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
326        a string to a long long, pretend we don't even have a long long." This is
327        done by checking for the strtoq, strtoll, and _strtoi64 functions.
329    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
330        pre-7.6 versions, which defined a global no_arg variable instead of putting
331        it in the RE class. (See also #8 below.)
333    3.  Remove a line of dead code, identified by coverity and reported by Nuno
334        Lopes.
336    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
338        (1) The include/exclude patterns were being applied to the whole pathnames
339            of files, instead of just to the final components.
341        (2) If there was more than one level of directory, the subdirectories were
342            skipped unless they satisfied the include/exclude conditions. This is
343            inconsistent with GNU grep (and could even be seen as contrary to the
344            pcregrep specification - which I improved to make it absolutely clear).
345            The action now is always to scan all levels of directory, and just
346            apply the include/exclude patterns to regular files.
348    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
349        --exclude_dir in the tests to avoid scanning .svn directories.
351    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
352        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
353        doesn't support NULs in patterns.
355    7.  Added some missing "const"s to declarations of static tables in
356        pcre_compile.c and pcre_dfa_exec.c.
358    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
359        caused by fix #2  above. (Subsequently also a second patch to fix the
360        first patch. And a third patch - this was a messy problem.)
362    9.  Applied Craig's patch to remove the use of push_back().
364    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
365        matching function regexec().
367    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
368        which, however, unlike Perl's \g{...}, are subroutine calls, not back
369        references. PCRE supports relative numbers with this syntax (I don't think
370        Oniguruma does).
372    12. Previously, a group with a zero repeat such as (...){0} was completely
373        omitted from the compiled regex. However, this means that if the group
374        was called as a subroutine from elsewhere in the pattern, things went wrong
375        (an internal error was given). Such groups are now left in the compiled
376        pattern, with a new opcode that causes them to be skipped at execution
377        time.
379    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
380        to the way PCRE behaves:
382        (a) A lone ] character is dis-allowed (Perl treats it as data).
384        (b) A back reference to an unmatched subpattern matches an empty string
385            (Perl fails the current match path).
387        (c) A data ] in a character class must be notated as \] because if the
388            first data character in a class is ], it defines an empty class. (In
389            Perl it is not possible to have an empty class.) The empty class []
390            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
391            The negative empty class [^] matches any one character, independently
392            of the DOTALL setting.
394    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
395        non-existent subpattern following a character class starting with ']' and
396        containing () gave an internal compiling error instead of "reference to
397        non-existent subpattern". Fortunately, when the pattern did exist, the
398        compiled code was correct. (When scanning forwards to check for the
399        existencd of the subpattern, it was treating the data ']' as terminating
400        the class, so got the count wrong. When actually compiling, the reference
401        was subsequently set up correctly.)
403    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
404        it was being rejected as not supported by pcre_dfa_exec(), even though
405        other assertions are supported. I have made pcre_dfa_exec() support
406        (*FAIL).
408    16. The implementation of 13c above involved the invention of a new opcode,
409        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
410        cannot be changed at match time, I realized I could make a small
411        improvement to matching performance by compiling OP_ALLANY instead of
412        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
413        on the OP_ANY path.
415    17. Compiling pcretest on Windows with readline support failed without the
416        following two fixes: (1) Make the unistd.h include conditional on
417        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
419    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
420        ncurses library to be included for pcretest when ReadLine support is
421        requested, but also to allow for it to be overridden. This patch came from
422        Daniel Bergström.
424    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
425        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
426        any errors with the current Unicode tables. Thanks to Peter Kankowski for
427        spotting this.
430    Version 7.6 28-Jan-08
431    ---------------------
433    1.  A character class containing a very large number of characters with
434        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
435        overflow.
437    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
438        HAVE_LONG_LONG is not defined.
440    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
441        bring them up to date and include new features. This patch includes:
443        - Fixed PH's badly added libz and libbz2 support.
444        - Fixed a problem with static linking.
445        - Added pcredemo. [But later removed - see 7 below.]
446        - Fixed dftables problem and added an option.
447        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
448            HAVE_LONG_LONG.
449        - Added readline support for pcretest.
450        - Added an listing of the option settings after cmake has run.
452    4.  A user submitted a patch to Makefile that makes it easy to create
453        "pcre.dll" under mingw when using Configure/Make. I added stuff to
454        Makefile.am that cause it to include this special target, without
455        affecting anything else. Note that the same mingw target plus all
456        the other distribution libraries and programs are now supported
457        when configuring with CMake (see 6 below) instead of with
458        Configure/Make.
460    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
461        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
462        exported in the Windows port". It has not yet been confirmed that the patch
463        solves the problem, but it does no harm.
465    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
466        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
467        with CMake, and also correct the comment about stack recursion.
469    7.  Remove the automatic building of pcredemo from the ./configure system and
470        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
471        of a program that users should build themselves after PCRE is installed, so
472        building it automatically is not really right. What is more, it gave
473        trouble in some build environments.
475    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
478    Version 7.5 10-Jan-08
479    ---------------------
481    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
482        values in parens when parsing an RE using the C++ wrapper."
484    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
485        Characters greater than 255 were excluded from the class instead of being
486        included.
488    3.  The same bug as (2) above applied to negated POSIX classes such as
489        [:^space:].
491    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
492        defined or documented. It seems to have been a typo for PCRE_STATIC, so
493        I have changed it.
495    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
496        first named subpattern) and a construct such as (?&a) would reference the
497        first named subpattern whose name started with "a" (in other words, the
498        length check was missing). Both these problems are fixed. "Subpattern name
499        expected" is now given for (?&) (a zero-length name), and this patch also
500        makes it give the same error for \k'' (previously it complained that that
501        was a reference to a non-existent subpattern).
503    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
504        this is right because (?- can be followed by option settings as well as by
505        digits. I have, however, made the messages clearer.
507    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
508        than the number used in the conditional) now cause a compile-time error.
509        This is actually not compatible with Perl, which accepts such patterns, but
510        treats the conditional as always being FALSE (as PCRE used to), but it
511        seems to me that giving a diagnostic is better.
513    8.  Change "alphameric" to the more common word "alphanumeric" in comments
514        and messages.
516    9.  Fix two occurrences of "backslash" in comments that should have been
517        "backspace".
519    10. Remove two redundant lines of code that can never be obeyed (their function
520        was moved elsewhere).
522    11. The program that makes PCRE's Unicode character property table had a bug
523        which caused it to generate incorrect table entries for sequences of
524        characters that have the same character type, but are in different scripts.
525        It amalgamated them into a single range, with the script of the first of
526        them. In other words, some characters were in the wrong script. There were
527        thirteen such cases, affecting characters in the following ranges:
529          U+002b0 - U+002c1
530          U+0060c - U+0060d
531          U+0061e - U+00612
532          U+0064b - U+0065e
533          U+0074d - U+0076d
534          U+01800 - U+01805
535          U+01d00 - U+01d77
536          U+01d9b - U+01dbf
537          U+0200b - U+0200f
538          U+030fc - U+030fe
539          U+03260 - U+0327f
540          U+0fb46 - U+0fbb1
541          U+10450 - U+1049d
543    12. The -o option (show only the matching part of a line) for pcregrep was not
544        compatible with GNU grep in that, if there was more than one match in a
545        line, it showed only the first of them. It now behaves in the same way as
546        GNU grep.
548    13. If the -o and -v options were combined for pcregrep, it printed a blank
549        line for every non-matching line. GNU grep prints nothing, and pcregrep now
550        does the same. The return code can be used to tell if there were any
551        non-matching lines.
553    14. Added --file-offsets and --line-offsets to pcregrep.
555    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
556        infinitely looping recursion. The bug was that positive lookaheads were not
557        being skipped when checking for a possible empty match (negative lookaheads
558        and both kinds of lookbehind were skipped).
560    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
561        inclusion of <windows.h> to before rather than after the definition of
562        INVALID_FILE_ATTRIBUTES (patch from David Byron).
564    17. Specifying a possessive quantifier with a specific limit for a Unicode
565        character property caused pcre_compile() to compile bad code, which led at
566        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
567        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
568        caused the error; without that there was no problem.
570    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
572    19. Added --enable-pcretest-libreadline.
574    20. In pcrecpp.cc, the variable 'count' was incremented twice in
575        RE::GlobalReplace(). As a result, the number of replacements returned was
576        double what it should be. I removed one of the increments, but Craig sent a
577        later patch that removed the other one (the right fix) and added unit tests
578        that check the return values (which was not done before).
580    21. Several CMake things:
582        (1) Arranged that, when cmake is used on Unix, the libraries end up with
583            the names libpcre and libpcreposix, not just pcre and pcreposix.
585        (2) The above change means that pcretest and pcregrep are now correctly
586            linked with the newly-built libraries, not previously installed ones.
590    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
591        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
592        UTF-8 newline character). The key issue is that the pattern starts .*;
593        this means that the match must be either at the beginning, or after a
594        newline. The bug was in the code for advancing after a failed match and
595        checking that the new position followed a newline. It was not taking
596        account of UTF-8 characters correctly.
598    23. PCRE was behaving differently from Perl in the way it recognized POSIX
599        character classes. PCRE was not treating the sequence [:...:] as a
600        character class unless the ... were all letters. Perl, however, seems to
601        allow any characters between [: and :], though of course it rejects as
602        unknown any "names" that contain non-letters, because all the known class
603        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
604        for example, whereas PCRE did not - it did not recognize a POSIX character
605        class. This seemed a bit dangerous, so the code has been changed to be
606        closer to Perl. The behaviour is not identical to Perl, because PCRE will
607        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
608        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
609        Perl does, and where it didn't before.
611    24. Rewrite so as to remove the single use of %n from pcregrep because in some
612        Windows environments %n is disabled by default.
615    Version 7.4 21-Sep-07
616    ---------------------
618    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
619        means that a class such as [\s] counted as "explicit reference to CR or
620        LF". That isn't really right - the whole point of the change was to try to
621        help when there was an actual mention of one of the two characters. So now
622        the change happens only if \r or \n (or a literal CR or LF) character is
623        encountered.
625    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
626        of both had grown to the point where there were only 3 bits left.
627        Fortunately, there was spare space in the data structure, and so I have
628        moved the internal flags into a new 16-bit field to free up more option
629        bits.
631    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
632        but did not set the internal JCHANGED flag - either of these is enough to
633        control the way the "get" function works - but the PCRE_INFO_JCHANGED
634        facility is supposed to tell if (?J) was ever used, so now (?J) at the
635        start sets both bits.
637    4.  Added options (at build time, compile time, exec time) to change \R from
638        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
640    5.  doc/pcresyntax.html was missing from the distribution.
642    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
643        compatibility, even though it is no longer used.
645    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
646        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
647        windows.h file is present (where different names are used). [This was
648        reversed later after testing - see 16 below.]
650    8.  Changed all #include <config.h> to #include "config.h". There were also
651        some further <pcre.h> cases that I changed to "pcre.h".
653    9.  When pcregrep was used with the --colour option, it missed the line ending
654        sequence off the lines that it output.
656    10. It was pointed out to me that arrays of string pointers cause lots of
657        relocations when a shared library is dynamically loaded. A technique of
658        using a single long string with a table of offsets can drastically reduce
659        these. I have refactored PCRE in four places to do this. The result is
660        dramatic:
662          Originally:                          290
663          After changing UCP table:            187
664          After changing error message table:   43
665          After changing table of "verbs"       36
666          After changing table of Posix names   22
668        Thanks to the folks working on Gregex for glib for this insight.
670    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
671        unicode-properties was also set.
673    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
675    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
676        checked only for CRLF.
678    14. Added casts to pcretest.c to avoid compiler warnings.
680    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
682    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
683        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
684        entirely. This removes changes made in 7 above.
686    17. The CMake files have been updated, and there is now more information about
687        building with CMake in the NON-UNIX-USE document.
690    Version 7.3 28-Aug-07
691    ---------------------
693     1. In the rejigging of the build system that eventually resulted in 7.1, the
694        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
695        brackets there is not right, since it causes compilers to look for an
696        installed pcre.h, not the version that is in the source that is being
697        compiled (which of course may be different). I have changed it back to:
699          #include "pcre.h"
701        I have a vague recollection that the change was concerned with compiling in
702        different directories, but in the new build system, that is taken care of
703        by the VPATH setting the Makefile.
705     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
706        when the subject happened to end in the byte 0x85 (e.g. if the last
707        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
708        characters but of course it shouldn't be taken as a newline when it is part
709        of another character. The bug was that, for an unlimited repeat of . in
710        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
711        characters when looking for a newline.
713     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
715     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
716        in debug output.
718     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
719        long printing in the pcrecpp unittest when running under MinGW.
721     6. ESC_K was left out of the EBCDIC table.
723     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
724        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
725        limit also applies to "virtual nesting" when a pattern is recursive, and in
726        this case 1000 isn't so big. I have been able to remove this limit at the
727        expense of backing off one optimization in certain circumstances. Normally,
728        when pcre_exec() would call its internal match() function recursively and
729        immediately return the result unconditionally, it uses a "tail recursion"
730        feature to save stack. However, when a subpattern that can match an empty
731        string has an unlimited repetition quantifier, it no longer makes this
732        optimization. That gives it a stack frame in which to save the data for
733        checking that an empty string has been matched. Previously this was taken
734        from the 1000-entry workspace that had been reserved. So now there is no
735        explicit limit, but more stack is used.
737     8. Applied Daniel's patches to solve problems with the import/export magic
738        syntax that is required for Windows, and which was going wrong for the
739        pcreposix and pcrecpp parts of the library. These were overlooked when this
740        problem was solved for the main library.
742     9. There were some crude static tests to avoid integer overflow when computing
743        the size of patterns that contain repeated groups with explicit upper
744        limits. As the maximum quantifier is 65535, the maximum group length was
745        set at 30,000 so that the product of these two numbers did not overflow a
746        32-bit integer. However, it turns out that people want to use groups that
747        are longer than 30,000 bytes (though not repeat them that many times).
748        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
749        made it possible to implement the integer overflow checks in a much more
750        dynamic way, which I have now done. The artificial limitation on group
751        length has been removed - we now have only the limit on the total length of
752        the compiled pattern, which depends on the LINK_SIZE setting.
754    10. Fixed a bug in the documentation for get/copy named substring when
755        duplicate names are permitted. If none of the named substrings are set, the
756        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
757        empty string.
759    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
760        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
761        because the ] is interpreted as the first data character and the
762        terminating ] is not found. PCRE has been made compatible with Perl in this
763        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
764        cause memory overwriting.
766    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
767        string has been matched (to stop an infinite loop). It was not recognizing
768        a conditional subpattern that could match an empty string if that
769        subpattern was within another subpattern. For example, it looped when
770        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
771        condition was not nested. This bug has been fixed.
773    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
774        past the start of the subject in the presence of bytes with the top bit
775        set, for example "\x8aBCD".
777    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
778        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
780    14. Optimized (?!) to (*FAIL).
782    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
783        This restricts code points to be within the range 0 to 0x10FFFF, excluding
784        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
785        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
786        does: it's just the validity check that is more restrictive.
788    16. Inserted checks for integer overflows during escape sequence (backslash)
789        processing, and also fixed erroneous offset values for syntax errors during
790        backslash processing.
792    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
793        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
795    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
796        caused an overrun.
798    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
799        something other than just ASCII characters) inside a group that had an
800        unlimited repeat caused a loop at compile time (while checking to see
801        whether the group could match an empty string).
803    20. Debugging a pattern containing \p or \P could cause a crash. For example,
804        [\P{Any}] did so. (Error in the code for printing property names.)
806    21. An orphan \E inside a character class could cause a crash.
808    22. A repeated capturing bracket such as (A)? could cause a wild memory
809        reference during compilation.
811    23. There are several functions in pcre_compile() that scan along a compiled
812        expression for various reasons (e.g. to see if it's fixed length for look
813        behind). There were bugs in these functions when a repeated \p or \P was
814        present in the pattern. These operators have additional parameters compared
815        with \d, etc, and these were not being taken into account when moving along
816        the compiled data. Specifically:
818        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
819            length.
821        (b) An item such as \pL+ within a repeated group could cause crashes or
822            loops.
824        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
825            "reference to non-existent subpattern" error.
827        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
829    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
830        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
832    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
834    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
835        character were causing crashes (broken optimization).
837    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
838        \p or \P) caused a compile-time loop.
840    28. More problems have arisen in unanchored patterns when CRLF is a valid line
841        break. For example, the unstudied pattern [\r\n]A does not match the string
842        "\r\nA" because change 7.0/46 below moves the current point on by two
843        characters after failing to match at the start. However, the pattern \nA
844        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
845        the same is true. There doesn't seem any very clean way out of this, but
846        what I have chosen to do makes the common cases work: PCRE now takes note
847        of whether there can be an explicit match for \r or \n anywhere in the
848        pattern, and if so, 7.0/46 no longer applies. As part of this change,
849        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
850        pattern has explicit CR or LF references.
852    29. Added (*CR) etc for changing newline setting at start of pattern.
855    Version 7.2 19-Jun-07
856    ---------------------
858     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
859        which is apparently normally available under Windows.
861     2. Re-jig the pcregrep tests with different newline settings in an attempt
862        to make them independent of the local environment's newline setting.
864     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
866     4. Some of the "internals" tests were previously cut out when the link size
867        was not 2, because the output contained actual offsets. The recent new
868        "Z" feature of pcretest means that these can be cut out, making the tests
869        usable with all link sizes.
871     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
872        stack recursion. This gives a massive performance boost under BSD, but just
873        a small improvement under Linux. However, it saves one field in the frame
874        in all cases.
876     6. Added more features from the forthcoming Perl 5.10:
878        (a) (?-n) (where n is a string of digits) is a relative subroutine or
879            recursion call. It refers to the nth most recently opened parentheses.
881        (b) (?+n) is also a relative subroutine call; it refers to the nth next
882            to be opened parentheses.
884        (c) Conditions that refer to capturing parentheses can be specified
885            relatively, for example, (?(-2)... or (?(+3)...
887        (d) \K resets the start of the current match so that everything before
888            is not part of it.
890        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
892        (f) \g{name} is another synonym - part of Perl 5.10's unification of
893            reference syntax.
895        (g) (?| introduces a group in which the numbering of parentheses in each
896            alternative starts with the same number.
898        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
900     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
903     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
904        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
905        for detecting groups that can match an empty string.
907     9. A pattern with a very large number of alternatives (more than several
908        hundred) was running out of internal workspace during the pre-compile
909        phase, where pcre_compile() figures out how much memory will be needed. A
910        bit of new cunning has reduced the workspace needed for groups with
911        alternatives. The 1000-alternative test pattern now uses 12 bytes of
912        workspace instead of running out of the 4096 that are available.
914    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
916    11. Applied patch from Google to remove an optimization that didn't quite work.
917        The report of the bug said:
919          pcrecpp::RE("a*").FullMatch("aaa") matches, while
920          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
921          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
923    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
924        it matched the wrong number of bytes.
927    Version 7.1 24-Apr-07
928    ---------------------
930     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
931        that is more "standard", making use of automake and other Autotools. There
932        is some re-arrangement of the files and adjustment of comments consequent
933        on this.
935     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
936        for recursive directory scanning broke on some systems because the files
937        are not scanned in any specific order and on different systems the order
938        was different. A call to "sort" has been inserted into RunGrepTest for the
939        approprate test as a short-term fix. In the longer term there may be an
940        alternative.
942     3. I had an email from Eric Raymond about problems translating some of PCRE's
943        man pages to HTML (despite the fact that I distribute HTML pages, some
944        people do their own conversions for various reasons). The problems
945        concerned the use of low-level troff macros .br and .in. I have therefore
946        removed all such uses from the man pages (some were redundant, some could
947        be replaced by .nf/.fi pairs). The 132html script that I use to generate
948        HTML has been updated to handle .nf/.fi and to complain if it encounters
949        .br or .in.
951     4. Updated comments in configure.ac that get placed in config.h.in and also
952        arranged for config.h to be included in the distribution, with the name
953        config.h.generic, for the benefit of those who have to compile without
954        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
956     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
957        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
958        makevp.bat for the current PCRE, using the additional files
959        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
961     6. A Windows user reported a minor discrepancy with test 2, which turned out
962        to be caused by a trailing space on an input line that had got lost in his
963        copy. The trailing space was an accident, so I've just removed it.
965     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
966        that is needed.
968     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
969        as "const" (a) because they are and (b) because it helps the PHP
970        maintainers who have recently made a script to detect big data structures
971        in the php code that should be moved to the .rodata section. I remembered
972        to update Builducptable as well, so it won't revert if ucptable.h is ever
973        re-created.
975     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
976        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
977        order to be able to cut out the UTF-8 tables in the latter when UTF-8
978        support is not required. This saves 1.5-2K of code, which is important in
979        some applications.
981        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
982        so as not to refer to the tables, even though these functions will never be
983        called when UTF-8 support is disabled. Otherwise there are problems with a
984        shared library.
986    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
988        (a) It was defining its arguments as char * instead of void *.
990        (b) It was assuming that all moves were upwards in memory; this was true
991            a long time ago when I wrote it, but is no longer the case.
993        The emulated memove() is provided for those environments that have neither
994        memmove() nor bcopy(). I didn't think anyone used it these days, but that
995        is clearly not the case, as these two bugs were recently reported.
997    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
998        and Detrail to create the HTML documentation, the .txt form of the man
999        pages, and it removes trailing spaces from listed files. It also creates
1000        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1001        case, it wraps all the #defines with #ifndefs. This script should be run
1002        before "make dist".
1004    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1005        with Unicode property support.
1007        (a) For a maximizing quantifier, if the two different cases of the
1008            character were of different lengths in their UTF-8 codings (there are
1009            some cases like this - I found 11), and the matching function had to
1010            back up over a mixture of the two cases, it incorrectly assumed they
1011            were both the same length.
1013        (b) When PCRE was configured to use the heap rather than the stack for
1014            recursion during matching, it was not correctly preserving the data for
1015            the other case of a UTF-8 character when checking ahead for a match
1016            while processing a minimizing repeat. If the check also involved
1017            matching a wide character, but failed, corruption could cause an
1018            erroneous result when trying to check for a repeat of the original
1019            character.
1021    13. Some tidying changes to the testing mechanism:
1023        (a) The RunTest script now detects the internal link size and whether there
1024            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1025            values substituted by "configure". (The RunGrepTest script already did
1026            this for UTF-8.) The configure.ac script no longer substitutes the
1027            relevant variables.
1029        (b) The debugging options /B and /D in pcretest show the compiled bytecode
1030            with length and offset values. This means that the output is different
1031            for different internal link sizes. Test 2 is skipped for link sizes
1032            other than 2 because of this, bypassing the problem. Unfortunately,
1033            there was also a test in test 3 (the locale tests) that used /B and
1034            failed for link sizes other than 2. Rather than cut the whole test out,
1035            I have added a new /Z option to pcretest that replaces the length and
1036            offset values with spaces. This is now used to make test 3 independent
1037            of link size. (Test 2 will be tidied up later.)
1039    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1040        segmentation fault instead of returning the appropriate error message.
1042    15. In multiline mode when the newline sequence was set to "any", the pattern
1043        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1044        This doesn't seem right; it now treats the CRLF combination as the line
1045        ending, and so does not match in that case. It's only a pattern such as ^$
1046        that would hit this one: something like ^ABC$ would have failed after \r
1047        and then tried again after \r\n.
1049    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1050        in an attempt to make files that differ only in their line terminators
1051        compare equal. This works on Linux.
1053    17. Under certain error circumstances pcregrep might try to free random memory
1054        as it exited. This is now fixed, thanks to valgrind.
1056    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1057        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1058        was because its rules for how to advance for /g after matching an empty
1059        string at the end of a line did not allow for this case. They now check for
1060        it specially.
1062    20. pcretest is supposed to handle patterns and data of any length, by
1063        extending its buffers when necessary. It was getting this wrong when the
1064        buffer for a data line had to be extended.
1066    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1067        CRLF as a newline sequence.
1069    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1070        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1071        I have nevertheless tidied it up.
1073    23. Added some casts to kill warnings from HP-UX ia64 compiler.
1075    24. Added a man page for pcre-config.
1078    Version 7.0 19-Dec-06
1079    ---------------------
1081     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1082        moving to gcc 4.1.1.
1084     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1085        sys/time.h, which is documented as needed for this function. It doesn't
1086        seem to matter on Linux, but it showed up on some releases of OS X.
1088     3. It seems that there are systems where bytes whose values are greater than
1089        127 match isprint() in the "C" locale. The "C" locale should be the
1090        default when a C program starts up. In most systems, only ASCII printing
1091        characters match isprint(). This difference caused the output from pcretest
1092        to vary, making some of the tests fail. I have changed pcretest so that:
1094        (a) When it is outputting text in the compiled version of a pattern, bytes
1095            other than 32-126 are always shown as hex escapes.
1097        (b) When it is outputting text that is a matched part of a subject string,
1098            it does the same, unless a different locale has been set for the match
1099            (using the /L modifier). In this case, it uses isprint() to decide.
1101     4. Fixed a major bug that caused incorrect computation of the amount of memory
1102        required for a compiled pattern when options that changed within the
1103        pattern affected the logic of the preliminary scan that determines the
1104        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1105        that the computed length was too small. The symptoms of this bug were
1106        either the PCRE error "internal error: code overflow" from pcre_compile(),
1107        or a glibc crash with a message such as "pcretest: free(): invalid next
1108        size (fast)". Examples of patterns that provoked this bug (shown in
1109        pcretest format) are:
1111          /(?-x: )/x
1112          /(?x)(?-x: \s*#\s*)/
1113          /((?i)[\x{c0}])/8
1114          /(?i:[\x{c0}])/8
1116        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1117        is now done differently.
1119     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1120        wrapper classes; (b) implement a new function in the C++ scanner that is
1121        more efficient than the old way of doing things because it avoids levels of
1122        recursion in the regex matching; (c) add a paragraph to the documentation
1123        for the FullMatch() function.
1125     6. The escape sequence \n was being treated as whatever was defined as
1126        "newline". Not only was this contrary to the documentation, which states
1127        that \n is character 10 (hex 0A), but it also went horribly wrong when
1128        "newline" was defined as CRLF. This has been fixed.
1130     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1131        was being set to -1 for the "end of line" case (supposedly a value that no
1132        character can have). Though this value is never used (the check for end of
1133        line is "zero bytes in current character"), it caused compiler complaints.
1134        I've changed it to 0xffffffff.
1136     8. In pcre_version.c, the version string was being built by a sequence of
1137        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1138        string (as it is for production releases) called a macro with an empty
1139        argument. The C standard says the result of this is undefined. The gcc
1140        compiler treats it as an empty string (which was what was wanted) but it is
1141        reported that Visual C gives an error. The source has been hacked around to
1142        avoid this problem.
1144     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1145        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1146        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1147        of them did).
1149    10. Originally, pcretest opened its input and output without "b"; then I was
1150        told that "b" was needed in some environments, so it was added for release
1151        5.0 to both the input and output. (It makes no difference on Unix-like
1152        systems.) Later I was told that it is wrong for the input on Windows. I've
1153        now abstracted the modes into two macros, to make it easier to fiddle with
1154        them, and removed "b" from the input mode under Windows.
1156    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1158    12. Added -help and --help to pcretest as an official way of being reminded
1159        of the options.
1161    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1162        and pcrecpp.cc because they annoy compilers at high warning levels.
1164    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1166    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1167        scripts are not C programs :-) and which was not noticed because it works
1168        on Linux.
1170    16. pcretest is supposed to handle any length of pattern and data line (as one
1171        line or as a continued sequence of lines) by extending its input buffer if
1172        necessary. This feature was broken for very long pattern lines, leading to
1173        a string of junk being passed to pcre_compile() if the pattern was longer
1174        than about 50K.
1176    17. I have done a major re-factoring of the way pcre_compile() computes the
1177        amount of memory needed for a compiled pattern. Previously, there was code
1178        that made a preliminary scan of the pattern in order to do this. That was
1179        OK when PCRE was new, but as the facilities have expanded, it has become
1180        harder and harder to keep it in step with the real compile phase, and there
1181        have been a number of bugs (see for example, 4 above). I have now found a
1182        cunning way of running the real compile function in a "fake" mode that
1183        enables it to compute how much memory it would need, while actually only
1184        ever using a few hundred bytes of working memory and without too many
1185        tests of the mode. This should make future maintenance and development
1186        easier. A side effect of this work is that the limit of 200 on the nesting
1187        depth of parentheses has been removed (though this was never a serious
1188        limitation, I suspect). However, there is a downside: pcre_compile() now
1189        runs more slowly than before (30% or more, depending on the pattern). I
1190        hope this isn't a big issue. There is no effect on runtime performance.
1192    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1193        newline (only possible for the last line of a file) and it was a
1194        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1196    19. Added additional timing features to pcretest. (1) The -tm option now times
1197        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1198        separate command line item, by a number that specifies the number of
1199        repeats to use when timing. The default is 50000; this gives better
1200        precision, but takes uncomfortably long for very large patterns.
1202    20. Extended pcre_study() to be more clever in cases where a branch of a
1203        subpattern has no definite first character. For example, (a*|b*)[cd] would
1204        previously give no result from pcre_study(). Now it recognizes that the
1205        first character must be a, b, c, or d.
1207    21. There was an incorrect error "recursive call could loop indefinitely" if
1208        a subpattern (or the entire pattern) that was being tested for matching an
1209        empty string contained only one non-empty item after a nested subpattern.
1210        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1211        incorrectly, because the \d was being skipped in the check.
1213    22. The pcretest program now has a new pattern option /B and a command line
1214        option -b, which is equivalent to adding /B to every pattern. This causes
1215        it to show the compiled bytecode, without the additional information that
1216        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1217        is the same as /B/I).
1219    23. A new optimization is now able automatically to treat some sequences such
1220        as a*b as a*+b. More specifically, if something simple (such as a character
1221        or a simple class like \d) has an unlimited quantifier, and is followed by
1222        something that cannot possibly match the quantified thing, the quantifier
1223        is automatically "possessified".
1225    24. A recursive reference to a subpattern whose number was greater than 39
1226        went wrong under certain circumstances in UTF-8 mode. This bug could also
1227        have affected the operation of pcre_study().
1229    25. Realized that a little bit of performance could be had by replacing
1230        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1232    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1234    27. Possessive quantifiers such as a++ were previously implemented by turning
1235        them into atomic groups such as ($>a+). Now they have their own opcodes,
1236        which improves performance. This includes the automatically created ones
1237        from 23 above.
1239    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1240        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1241        the first matched character to be a colon. This applied both to named and
1242        numbered groups.
1244    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1246    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1247        building PCRE on Windows easier, so I have included it in the distribution.
1249    31. There is now a check in pcretest against a ridiculously large number being
1250        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1251        loop, the loop is abandoned.
1253    32. Forward references to subpatterns in conditions such as (?(2)...) where
1254        subpattern 2 is defined later cause pcre_compile() to search forwards in
1255        the pattern for the relevant set of parentheses. This search went wrong
1256        when there were unescaped parentheses in a character class, parentheses
1257        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1259    33. "Subroutine" calls and backreferences were previously restricted to
1260        referencing subpatterns earlier in the regex. This restriction has now
1261        been removed.
1263    34. Added a number of extra features that are going to be in Perl 5.10. On the
1264        whole, these are just syntactic alternatives for features that PCRE had
1265        previously implemented using the Python syntax or my own invention. The
1266        other formats are all retained for compatibility.
1268        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1269            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1270            also .NET compatible.
1272        (b) A recursion or subroutine call to a named group can now be defined as
1273            (?&name) as well as (?P>name).
1275        (c) A backreference to a named group can now be defined as \k<name> or
1276            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1277            5.10, are also .NET compatible.
1279        (d) A conditional reference to a named group can now use the syntax
1280            (?(<name>) or (?('name') as well as (?(name).
1282        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1283            groups (named and numbered) that are never evaluated inline, but can be
1284            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1285            is always false. There may be only one alternative in such a group.
1287        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1288            as the simple (?(R). The condition is true only if the most recent
1289            recursion is that of the given number or name. It does not search out
1290            through the entire recursion stack.
1292        (g) The escape \gN or \g{N} has been added, where N is a positive or
1293            negative number, specifying an absolute or relative reference.
1295    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1296        some "unreachable code" warnings.
1298    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1299        things, this adds five new scripts.
1301    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1302        There were also incompatibilities regarding the handling of \Q..\E inside
1303        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1304        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1306    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1307        matches an empty string, and forcibly breaks the loop. There were bugs in
1308        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1309        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1310        separate and independent bugs (that affected different cases) have been
1311        fixed.
1313    39. Refactored the code to abolish the use of different opcodes for small
1314        capturing bracket numbers. This is a tidy that I avoided doing when I
1315        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1316        The new approach is not only tidier, it makes it possible to reduce the
1317        memory needed to fix the previous bug (38).
1319    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1320        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1321        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1322        mode.
1324    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1325        report.
1327    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1328        copy construction and assignment in the C++ wrapper.
1330    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1331        couple of bugs that could have given wrong results in the "--newline=crlf"
1332        case.
1334    44. Added a number of casts and did some reorganization of signed/unsigned int
1335        variables following suggestions from Dair Grant. Also renamed the variable
1336        "this" as "item" because it is a C++ keyword.
1338    45. Arranged for dftables to add
1340          #include "pcre_internal.h"
1342        to pcre_chartables.c because without it, gcc 4.x may remove the array
1343        definition from the final binary if PCRE is built into a static library and
1344        dead code stripping is activated.
1346    46. For an unanchored pattern, if a match attempt fails at the start of a
1347        newline sequence, and the newline setting is CRLF or ANY, and the next two
1348        characters are CRLF, advance by two characters instead of one.
1351    Version 6.7 04-Jul-06
1352    ---------------------
1354     1. In order to handle tests when input lines are enormously long, pcretest has
1355        been re-factored so that it automatically extends its buffers when
1356        necessary. The code is crude, but this _is_ just a test program. The
1357        default size has been increased from 32K to 50K.
1359     2. The code in pcre_study() was using the value of the re argument before
1360        testing it for NULL. (Of course, in any sensible call of the function, it
1361        won't be NULL.)
1363     3. The memmove() emulation function in pcre_internal.h, which is used on
1364        systems that lack both memmove() and bcopy() - that is, hardly ever -
1365        was missing a "static" storage class specifier.
1367     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1368        containing an extended class (one that cannot be represented by a bitmap
1369        because it contains high-valued characters or Unicode property items, e.g.
1370        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1371        pattern, but PCRE should not loop if you do not (it no longer does).
1372        [Detail: two cases were found: (a) a repeated subpattern containing an
1373        extended class; (b) a recursive reference to a subpattern that followed a
1374        previous extended class. It wasn't skipping over the extended class
1375        correctly when UTF-8 mode was not set.]
1377     5. A negated single-character class was not being recognized as fixed-length
1378        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1379        compile error "lookbehind assertion is not fixed length".
1381     6. The RunPerlTest auxiliary script was showing an unexpected difference
1382        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1383        write a Perl script that can interpret lines of an input file either as
1384        byte characters or as UTF-8, which is what "perltest" was being required to
1385        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1386        can't do is switch easily at run time between having the "use utf8;" pragma
1387        or not. In the end, I fudged it by using the RunPerlTest script to insert
1388        "use utf8;" explicitly for the UTF-8 tests.
1390     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1391        the end of the subject string, contrary to the documentation and to what
1392        Perl does. This was true of both matching functions. Now it matches only at
1393        the start of the subject and immediately after *internal* newlines.
1395     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1396        a pointer to an int instead of a pointer to an unsigned long int. This
1397        caused problems on 64-bit systems.
1399     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1400        instance of the 'standard' template library not being so standard".
1402    10. There was no check on the number of named subpatterns nor the maximum
1403        length of a subpattern name. The product of these values is used to compute
1404        the size of the memory block for a compiled pattern. By supplying a very
1405        long subpattern name and a large number of named subpatterns, the size
1406        computation could be caused to overflow. This is now prevented by limiting
1407        the length of names to 32 characters, and the number of named subpatterns
1408        to 10,000.
1410    11. Subpatterns that are repeated with specific counts have to be replicated in
1411        the compiled pattern. The size of memory for this was computed from the
1412        length of the subpattern and the repeat count. The latter is limited to
1413        65535, but there was no limit on the former, meaning that integer overflow
1414        could in principle occur. The compiled length of a repeated subpattern is
1415        now limited to 30,000 bytes in order to prevent this.
1417    12. Added the optional facility to have named substrings with the same name.
1419    13. Added the ability to use a named substring as a condition, using the
1420        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1421        are numbers (not recommended). Forward references are permitted.
1423    14. Added forward references in named backreferences (if you see what I mean).
1425    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1426        pattern could run off the end of the subject. For example, the pattern
1427        "(?s)(.{1,5})"8 did this with the subject "ab".
1429    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1430        PCRE_CASELESS was set when matching characters that were quantified with ?
1431        or *.
1433    17. A character class other than a single negated character that had a minimum
1434        but no maximum quantifier - for example [ab]{6,} - was not handled
1435        correctly by pce_dfa_exec(). It would match only one character.
1437    18. A valid (though odd) pattern that looked like a POSIX character
1438        class but used an invalid character after [ (for example [[,abc,]]) caused
1439        pcre_compile() to give the error "Failed: internal error: code overflow" or
1440        in some cases to crash with a glibc free() error. This could even happen if
1441        the pattern terminated after [[ but there just happened to be a sequence of
1442        letters, a binary zero, and a closing ] in the memory that followed.
1444    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1445        over the years. Originally (before any Unicode support), just the bottom 8
1446        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1447        output from "man perlunicode" includes this:
1449          The regular expression compiler produces polymorphic opcodes.  That
1450          is, the pattern adapts to the data and automatically switches to
1451          the Unicode character scheme when presented with Unicode data--or
1452          instead uses a traditional byte scheme when presented with byte
1453          data.
1455        Sadly, a wide octal escape does not cause a switch, and in a string with
1456        no other multibyte characters, these octal escapes are treated as before.
1457        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1458        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1459        Unicode string.
1461        I have not perpetrated such confusion in PCRE. Up till now, it took just
1462        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1463        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1464        translate to the appropriate multibyte character.
1466    29. Applied some refactoring to reduce the number of warnings from Microsoft
1467        and Borland compilers. This has included removing the fudge introduced
1468        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1469        a warning about an unused variable.
1471    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1472        characters since release 4.0, because Perl (from release 5.004) does not.
1473        [Or at least, is documented not to: some releases seem to be in conflict
1474        with the documentation.] However, when a pattern was studied with
1475        pcre_study() and all its branches started with \s, PCRE still included VT
1476        as a possible starting character. Of course, this did no harm; it just
1477        caused an unnecessary match attempt.
1479    22. Removed a now-redundant internal flag bit that recorded the fact that case
1480        dependency changed within the pattern. This was once needed for "required
1481        byte" processing, but is no longer used. This recovers a now-scarce options
1482        bit. Also moved the least significant internal flag bit to the most-
1483        significant bit of the word, which was not previously used (hangover from
1484        the days when it was an int rather than a uint) to free up another bit for
1485        the future.
1487    23. Added support for CRLF line endings as well as CR and LF. As well as the
1488        default being selectable at build time, it can now be changed at runtime
1489        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1490        specify that it is scanning data with non-default line endings.
1492    24. Changed the definition of CXXLINK to make it agree with the definition of
1493        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1495    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1496        recursions. This makes a big different to stack usage for some patterns.
1498    26. If a subpattern containing a named recursion or subroutine reference such
1499        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1500        the space required for the compiled pattern went wrong and gave too small a
1501        value. Depending on the environment, this could lead to "Failed: internal
1502        error: code overflow at offset 49" or "glibc detected double free or
1503        corruption" errors.
1505    27. Applied patches from Google (a) to support the new newline modes and (b) to
1506        advance over multibyte UTF-8 characters in GlobalReplace.
1508    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1509        difference for some implementation of PCRE in some Windows version.
1511    29. Added some extra testing facilities to pcretest:
1513        \q<number>   in a data line sets the "match limit" value
1514        \Q<number>   in a data line sets the "match recursion limt" value
1515        -S <number>  sets the stack size, where <number> is in megabytes
1517        The -S option isn't available for Windows.
1520    Version 6.6 06-Feb-06
1521    ---------------------
1523     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1524        in pcreposix.h. I have copied the definition from pcre.h.
1526     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1527        because pcre.h is no longer a built file.
1529     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1530        not normally included in the compiled code.
1533    Version 6.5 01-Feb-06
1534    ---------------------
1536     1. When using the partial match feature with pcre_dfa_exec(), it was not
1537        anchoring the second and subsequent partial matches at the new starting
1538        point. This could lead to incorrect results. For example, with the pattern
1539        /1234/, partially matching against "123" and then "a4" gave a match.
1541     2. Changes to pcregrep:
1543        (a) All non-match returns from pcre_exec() were being treated as failures
1544            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1545            error message is output. Some extra information is given for the
1546            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1547            probably the only errors that are likely to be caused by users (by
1548            specifying a regex that has nested indefinite repeats, for instance).
1549            If there are more than 20 of these errors, pcregrep is abandoned.
1551        (b) A binary zero was treated as data while matching, but terminated the
1552            output line if it was written out. This has been fixed: binary zeroes
1553            are now no different to any other data bytes.
1555        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1556            used to set a locale for matching. The --locale=xxxx long option has
1557            been added (no short equivalent) to specify a locale explicitly on the
1558            pcregrep command, overriding the environment variables.
1560        (d) When -B was used with -n, some line numbers in the output were one less
1561            than they should have been.
1563        (e) Added the -o (--only-matching) option.
1565        (f) If -A or -C was used with -c (count only), some lines of context were
1566            accidentally printed for the final match.
1568        (g) Added the -H (--with-filename) option.
1570        (h) The combination of options -rh failed to suppress file names for files
1571            that were found from directory arguments.
1573        (i) Added the -D (--devices) and -d (--directories) options.
1575        (j) Added the -F (--fixed-strings) option.
1577        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1579        (l) Added the --colo(u)r option.
1581        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1582            is not present by default.
1584     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1585        items such as (?R) or (?1), when the recursion could match a number of
1586        alternatives. If it matched one of the alternatives, but subsequently,
1587        outside the recursion, there was a failure, the code tried to back up into
1588        the recursion. However, because of the way PCRE is implemented, this is not
1589        possible, and the result was an incorrect result from the match.
1591        In order to prevent this happening, the specification of recursion has
1592        been changed so that all such subpatterns are automatically treated as
1593        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1595     4. I had overlooked the fact that, in some locales, there are characters for
1596        which isalpha() is true but neither isupper() nor islower() are true. In
1597        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1598        and ordfeminine) are like this. This affected the treatment of \w and \W
1599        when they appeared in character classes, but not when they appeared outside
1600        a character class. The bit map for "word" characters is now created
1601        separately from the results of isalnum() instead of just taking it from the
1602        upper, lower, and digit maps. (Plus the underscore character, of course.)
1604     5. The above bug also affected the handling of POSIX character classes such as
1605        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1606        permanent tables. Instead, the bit maps for such a class were previously
1607        created as the appropriate unions of the upper, lower, and digit bitmaps.
1608        Now they are created by subtraction from the [[:word:]] class, which has
1609        its own bitmap.
1611     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1612        It is created by subtracting the vertical space characters (\x09, \x0a,
1613        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1614        subtraction was done in the overall bitmap for a character class, meaning
1615        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1616        be recognized. This bug has been fixed.
1618     7. Patches from the folks at Google:
1620          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1621          real life, but is still worth protecting against".
1623          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1624          regular expressions".
1626          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1627          have it.
1629          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1630          "configure" and the latter not, in order to fix a problem somebody had
1631          with compiling the Arg class on HP-UX.
1633          (e) Improve the error-handling of the C++ wrapper a little bit.
1635          (f) New tests for checking recursion limiting.
1637     8. The pcre_memmove() function, which is used only if the environment does not
1638        have a standard memmove() function (and is therefore rarely compiled),
1639        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1640        returning a result (though PCRE never actually uses the result).
1642     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1643        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1644        returned instead of calling malloc() with an overflowing number that would
1645        most likely cause subsequent chaos.
1647    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1649    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1650        with this option is matched, the nmatch and pmatch options of regexec() are
1651        ignored.
1653    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1654        provided in case anyone wants to the the POSIX interface with UTF-8
1655        strings.
1657    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1658        C++ linking (needed for some HP-UX environments).
1660    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1661        (unused parameter) and in the pcre_printint() function (omitted "default"
1662        switch label when the default is to do nothing).
1664    15. Added some code to make it possible, when PCRE is compiled as a C++
1665        library, to replace subject pointers for pcre_exec() with a smart pointer
1666        class, thus making it possible to process discontinuous strings.
1668    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1669        much the same function. They were added by different people who were trying
1670        to make PCRE easy to compile on non-Unix systems. It has been suggested
1671        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1672        for compiling on Windows systems. I have therefore replaced it with
1673        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1674        defaults to "extern" for C or "extern C" for C++, which works fine on
1675        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1676        SCOPE with something explicit in config.h. In addition:
1678        (a) pcreposix.h still had just "extern" instead of either of these macros;
1679            I have replaced it with PCRE_DATA_SCOPE.
1681        (b) Functions such as _pcre_xclass(), which are internal to the library,
1682            but external in the C sense, all had PCRE_EXPORT in their definitions.
1683            This is apparently wrong for the Windows case, so I have removed it.
1684            (It makes no difference on Unix-like systems.)
1686    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1687        of recursive calls to match(). This is different to MATCH_LIMIT because
1688        that limits the total number of calls to match(), not all of which increase
1689        the depth of recursion. Limiting the recursion depth limits the amount of
1690        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1691        when PCRE is compiled, and changed at run time. A patch from Google adds
1692        this functionality to the C++ interface.
1694    18. Changes to the handling of Unicode character properties:
1696        (a) Updated the table to Unicode 4.1.0.
1698        (b) Recognize characters that are not in the table as "Cn" (undefined).
1700        (c) I revised the way the table is implemented to a much improved format
1701            which includes recognition of ranges. It now supports the ranges that
1702            are defined in UnicodeData.txt, and it also amalgamates other
1703            characters into ranges. This has reduced the number of entries in the
1704            table from around 16,000 to around 3,000, thus reducing its size
1705            considerably. I realized I did not need to use a tree structure after
1706            all - a binary chop search is just as efficient. Having reduced the
1707            number of entries, I extended their size from 6 bytes to 8 bytes to
1708            allow for more data.
1710        (d) Added support for Unicode script names via properties such as \p{Han}.
1712    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1713        matching that character.
1715    20. When matching a repeated Unicode property with a minimum greater than zero,
1716        (for example \pL{2,}), PCRE could look past the end of the subject if it
1717        reached it while seeking the minimum number of characters. This could
1718        happen only if some of the characters were more than one byte long, because
1719        there is a check for at least the minimum number of bytes.
1721    21. Refactored the implementation of \p and \P so as to be more general, to
1722        allow for more different types of property in future. This has changed the
1723        compiled form incompatibly. Anybody with saved compiled patterns that use
1724        \p or \P will have to recompile them.
1726    22. Added "Any" and "L&" to the supported property types.
1728    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1729        but give a compile time error if the value is greater than 0xff.
1731    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1732        accidentally not being installed or uninstalled.
1734    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1735        made were to insert the current release number. This seemed silly, because
1736        it made things harder for people building PCRE on systems that don't run
1737        "configure". I have turned pcre.h into a distributed file, no longer built
1738        by "configure", with the version identification directly included. There is
1739        no longer a pcre.h.in file.
1741        However, this change necessitated a change to the pcre-config script as
1742        well. It is built from pcre-config.in, and one of the substitutions was the
1743        release number. I have updated configure.ac so that ./configure now finds
1744        the release number by grepping pcre.h.
1746    26. Added the ability to run the tests under valgrind.
1749    Version 6.4 05-Sep-05
1750    ---------------------
1752     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1753        "--" to be printed when multiple files were scanned, even when none of the
1754        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1755        consider it to be a bug, and have restored the previous behaviour.
1757     2. A couple of code tidies to get rid of compiler warnings.
1759     3. The pcretest program used to cheat by referring to symbols in the library
1760        whose names begin with _pcre_. These are internal symbols that are not
1761        really supposed to be visible externally, and in some environments it is
1762        possible to suppress them. The cheating is now confined to including
1763        certain files from the library's source, which is a bit cleaner.
1765     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1766        file's purpose clearer.
1768     5. Reorganized pcre_ucp_findchar().
1771    Version 6.3 15-Aug-05
1772    ---------------------
1774     1. The file libpcre.pc.in did not have general read permission in the tarball.
1776     2. There were some problems when building without C++ support:
1778        (a) If C++ support was not built, "make install" and "make test" still
1779            tried to test it.
1781        (b) There were problems when the value of CXX was explicitly set. Some
1782            changes have been made to try to fix these, and ...
1784        (c) --disable-cpp can now be used to explicitly disable C++ support.
1786        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1787            backslash in a target when C++ was disabled. This confuses some
1788            versions of "make", apparently. Using an intermediate variable solves
1789            this. (Same for CPP_LOBJ.)
1791     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1792        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1793        necessary on certain architectures.
1795     4. Added a setting of -export-symbols-regex to the link command to remove
1796        those symbols that are exported in the C sense, but actually are local
1797        within the library, and not documented. Their names all begin with
1798        "_pcre_". This is not a perfect job, because (a) we have to except some
1799        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1800        available (and never for static libraries). I have made a note to try to
1801        find a way round (a) in the future.
1804    Version 6.2 01-Aug-05
1805    ---------------------
1807     1. There was no test for integer overflow of quantifier values. A construction
1808        such as {1111111111111111} would give undefined results. What is worse, if
1809        a minimum quantifier for a parenthesized subpattern overflowed and became
1810        negative, the calculation of the memory size went wrong. This could have
1811        led to memory overwriting.
1813     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1815     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1816        operating environments where this matters.
1818     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1819        PCRE options from within the C++ wrapper.
1821     5. Named capturing subpatterns were not being correctly counted when a pattern
1822        was compiled. This caused two problems: (a) If there were more than 100
1823        such subpatterns, the calculation of the memory needed for the whole
1824        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1825        back references of the form \12, where the number was greater than 9, were
1826        not recognized as back references, even though there were sufficient
1827        previous subpatterns.
1829     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1830        versions of gcc, e.g. 2.95.4.
1833    Version 6.1 21-Jun-05
1834    ---------------------
1836     1. There was one reference to the variable "posix" in pcretest.c that was not
1837        surrounded by "#if !defined NOPOSIX".
1839     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1840        the cross-check on the old pcre_info() function, for the benefit of the
1841        cut-down version of PCRE that is currently imported into Exim.
1843     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1844        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1845        patterns that start (?i) but I don't think that matters. The use of (?i) is
1846        just an example; this all applies to the other options as well.
1848     4. Since libtool seems to echo the compile commands it is issuing, the output
1849        from "make" can be reduced a bit by putting "@" in front of each libtool
1850        compile command.
1852     5. Patch from the folks at Google for configure.in to be a bit more thorough
1853        in checking for a suitable C++ installation before trying to compile the
1854        C++ stuff. This should fix a reported problem when a compiler was present,
1855        but no suitable headers.
1857     6. The man pages all had just "PCRE" as their title. I have changed them to
1858        be the relevant file name. I have also arranged that these names are
1859        retained in the file doc/pcre.txt, which is a concatenation in text format
1860        of all the man pages except the little individual ones for each function.
1862     7. The NON-UNIX-USE file had not been updated for the different set of source
1863        files that come with release 6. I also added a few comments about the C++
1864        wrapper.
1867    Version 6.0 07-Jun-05
1868    ---------------------
1870     1. Some minor internal re-organization to help with my DFA experiments.
1872     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1873        didn't matter for the library itself when fully configured, but did matter
1874        when compiling without UCP support, or within Exim, where the ucp files are
1875        not imported.
1877     3. Refactoring of the library code to split up the various functions into
1878        different source modules. The addition of the new DFA matching code (see
1879        below) to a single monolithic source would have made it really too
1880        unwieldy, quite apart from causing all the code to be include in a
1881        statically linked application, when only some functions are used. This is
1882        relevant even without the DFA addition now that patterns can be compiled in
1883        one application and matched in another.
1885        The downside of splitting up is that there have to be some external
1886        functions and data tables that are used internally in different modules of
1887        the library but which are not part of the API. These have all had their
1888        names changed to start with "_pcre_" so that they are unlikely to clash
1889        with other external names.
1891     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1892        a different (DFA) algorithm. Although it is slower than the original
1893        function, it does have some advantages for certain types of matching
1894        problem.
1896     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1897        including restarting after a partial match.
1899     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1900        defined when compiling for Windows was sent to me. I have put it into the
1901        code, though I have no means of testing or verifying it.
1903     7. Added the pcre_refcount() auxiliary function.
1905     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1906        match before or at the first newline in the subject string. In pcretest,
1907        the /f option on a pattern can be used to set this.
1909     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1910        would behave wrongly. This has been present in PCRE since release 4.0.
1912    10. A number of changes to the pcregrep command:
1914        (a) Refactored how -x works; insert ^(...)$ instead of setting
1915            PCRE_ANCHORED and checking the length, in preparation for adding
1916            something similar for -w.
1918        (b) Added the -w (match as a word) option.
1920        (c) Refactored the way lines are read and buffered so as to have more
1921            than one at a time available.
1923        (d) Implemented a pcregrep test script.
1925        (e) Added the -M (multiline match) option. This allows patterns to match
1926            over several lines of the subject. The buffering ensures that at least
1927            8K, or the rest of the document (whichever is the shorter) is available
1928            for matching (and similarly the previous 8K for lookbehind assertions).
1930        (f) Changed the --help output so that it now says
1932              -w, --word-regex(p)
1934            instead of two lines, one with "regex" and the other with "regexp"
1935            because that confused at least one person since the short forms are the
1936            same. (This required a bit of code, as the output is generated
1937            automatically from a table. It wasn't just a text change.)
1939        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1940            option but starts with a hyphen. Could be a pattern or a path name
1941            starting with a hyphen, for instance.
1943        (h) "-" can be given as a file name to represent stdin.
1945        (i) When file names are being printed, "(standard input)" is used for
1946            the standard input, for compatibility with GNU grep. Previously
1947            "<stdin>" was used.
1949        (j) The option --label=xxx can be used to supply a name to be used for
1950            stdin when file names are being printed. There is no short form.
1952        (k) Re-factored the options decoding logic because we are going to add
1953            two more options that take data. Such options can now be given in four
1954            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1956        (l) Added the -A, -B, and -C options for requesting that lines of context
1957            around matches be printed.
1959        (m) Added the -L option to print the names of files that do not contain
1960            any matching lines, that is, the complement of -l.
1962        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1963            continue to scan other files.
1965        (o) The -s option was incorrectly implemented. For compatibility with other
1966            greps, it now suppresses the error message for a non-existent or non-
1967            accessible file (but not the return code). There is a new option called
1968            -q that suppresses the output of matching lines, which was what -s was
1969            previously doing.
1971        (p) Added --include and --exclude options to specify files for inclusion
1972            and exclusion when recursing.
1974    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1975        Hopefully, it now does.
1977    12. Missing cast in pcre_study().
1979    13. Added an "uninstall" target to the makefile.
1981    14. Replaced "extern" in the function prototypes in Makefile.in with
1982        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1983        world, but is set differently for Windows.
1985    15. Added a second compiling function called pcre_compile2(). The only
1986        difference is that it has an extra argument, which is a pointer to an
1987        integer error code. When there is a compile-time failure, this is set
1988        non-zero, in addition to the error test pointer being set to point to an
1989        error message. The new argument may be NULL if no error number is required
1990        (but then you may as well call pcre_compile(), which is now just a
1991        wrapper). This facility is provided because some applications need a
1992        numeric error indication, but it has also enabled me to tidy up the way
1993        compile-time errors are handled in the POSIX wrapper.
1995    16. Added VPATH=.libs to the makefile; this should help when building with one
1996        prefix path and installing with another. (Or so I'm told by someone who
1997        knows more about this stuff than I do.)
1999    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2000        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2001        match everything, including newlines. This is not POSIX-compatible, but
2002        somebody wanted the feature. From pcretest it can be activated by using
2003        both the P and the s flags.
2005    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2007    19. libpcre.pc was being incorrectly installed as executable.
2009    20. A couple of places in pcretest check for end-of-line by looking for '\n';
2010        it now also looks for '\r' so that it will work unmodified on Windows.
2012    21. Added Google's contributed C++ wrapper to the distribution.
2014    22. Added some untidy missing memory free() calls in pcretest, to keep
2015        Electric Fence happy when testing.
2019    Version 5.0 13-Sep-04
2020    ---------------------
2022     1. Internal change: literal characters are no longer packed up into items
2023        containing multiple characters in a single byte-string. Each character
2024        is now matched using a separate opcode. However, there may be more than one
2025        byte in the character in UTF-8 mode.
2027     2. The pcre_callout_block structure has two new fields: pattern_position and
2028        next_item_length. These contain the offset in the pattern to the next match
2029        item, and its length, respectively.
2031     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2032        insertion of callouts before each pattern item. Added the /C option to
2033        pcretest to make use of this.
2035     4. On the advice of a Windows user, the lines
2037          #if defined(_WIN32) || defined(WIN32)
2038          _setmode( _fileno( stdout ), 0x8000 );
2039          #endif  /* defined(_WIN32) || defined(WIN32) */
2041        have been added to the source of pcretest. This apparently does useful
2042        magic in relation to line terminators.
2044     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2045        for the benefit of those environments where the "b" makes a difference.
2047     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2048        to know about it. I have put a hack into configure.in that adds in code
2049        to set GCC=yes if CC=icc. This seems to end up at a point in the
2050        generated configure script that is early enough to affect the setting of
2051        compiler options, which is what is needed, but I have no means of testing
2052        whether it really works. (The user who reported this had patched the
2053        generated configure script, which of course I cannot do.)
2055        LATER: After change 22 below (new libtool files), the configure script
2056        seems to know about icc (and also ecc). Therefore, I have commented out
2057        this hack in configure.in.
2059     7. Added support for pkg-config (2 patches were sent in).
2061     8. Negated POSIX character classes that used a combination of internal tables
2062        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2063        [[:^ascii]]. Typically, they would match almost any characters. The other
2064        POSIX classes were not broken in this way.
2066     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2067        to find the match, as PCRE was deluded into thinking that the match had to
2068        start at the start point or following a newline. The same bug applied to
2069        patterns with negative forward assertions or any backward assertions
2070        preceding ".*" at the start, unless the pattern required a fixed first
2071        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2073    10. In UTF-8 mode, when moving forwards in the subject after a failed match
2074        starting at the last subject character, bytes beyond the end of the subject
2075        string were read.
2077    11. Renamed the variable "class" as "classbits" to make life easier for C++
2078        users. (Previously there was a macro definition, but it apparently wasn't
2079        enough.)
2081    12. Added the new field "tables" to the extra data so that tables can be passed
2082        in at exec time, or the internal tables can be re-selected. This allows
2083        a compiled regex to be saved and re-used at a later time by a different
2084        program that might have everything at different addresses.
2086    13. Modified the pcre-config script so that, when run on Solaris, it shows a
2087        -R library as well as a -L library.
2089    14. The debugging options of pcretest (-d on the command line or D on a
2090        pattern) showed incorrect output for anything following an extended class
2091        that contained multibyte characters and which was followed by a quantifier.
2093    15. Added optional support for general category Unicode character properties
2094        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2095        support. It adds about 90K to the size of the library. The meanings of the
2096        inbuilt class escapes such as \d and \s have NOT been changed.
2098    16. Updated pcredemo.c to include calls to free() to release the memory for the
2099        compiled pattern.
2101    17. The generated file chartables.c was being created in the source directory
2102        instead of in the building directory. This caused the build to fail if the
2103        source directory was different from the building directory, and was
2104        read-only.
2106    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2107        file. No doubt somebody will tell me if they don't make sense... Also added
2108        Dan Mooney's comments about building on OpenVMS.
2110    19. Added support for partial matching via the PCRE_PARTIAL option for
2111        pcre_exec() and the \P data escape in pcretest.
2113    20. Extended pcretest with 3 new pattern features:
2115        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2116              write the compiled pattern to the file whose name is "rest-of-line".
2117              This is a straight binary dump of the data, with the saved pointer to
2118              the character tables forced to be NULL. The study data, if any, is
2119              written too. After writing, pcretest reads a new pattern.
2121        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2122              compiled pattern from the given file. There must not be any
2123              occurrences of "<" in the file name (pretty unlikely); if there are,
2124              pcretest will instead treat the initial "<" as a pattern delimiter.
2125              After reading in the pattern, pcretest goes on to read data lines as
2126              usual.
2128        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2129              and 16-bit fields in a compiled pattern, to simulate a pattern that
2130              was compiled on a host of opposite endianness.
2132    21. The pcre-exec() function can now cope with patterns that were compiled on
2133        hosts of opposite endianness, with this restriction:
2135          As for any compiled expression that is saved and used later, the tables
2136          pointer field cannot be preserved; the extra_data field in the arguments
2137          to pcre_exec() should be used to pass in a tables address if a value
2138          other than the default internal tables were used at compile time.
2140    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2141        now diagnosed as an error. Previously, most of the time, a negative number
2142        would have been treated as zero, but if in addition "ovector" was passed as
2143        NULL, a crash could occur.
2145    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2146        new versions from the libtool 1.5 distribution (the last one is a copy of
2147        a file called libtool.m4). This seems to have fixed the need to patch
2148        "configure" to support Darwin 1.3 (which I used to do). However, I still
2149        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2150        workstation).
2152    24. Changed the PCRE licence to be the more standard "BSD" licence.
2155    Version 4.5 01-Dec-03
2156    ---------------------
2158     1. There has been some re-arrangement of the code for the match() function so
2159        that it can be compiled in a version that does not call itself recursively.
2160        Instead, it keeps those local variables that need separate instances for
2161        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2162        needs to "recurse". Keeping track of where control must go is done by means
2163        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2164        hide most of the details from the main code, and operates only if
2165        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2166        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2167        operating.
2169        To make it easier for callers to provide specially tailored get/free
2170        functions for this usage, two new functions, pcre_stack_malloc, and
2171        pcre_stack_free, are used. They are always called in strict stacking order,
2172        and the size of block requested is always the same.
2174        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2175        PCRE has been compiled to use the stack or the heap for recursion. The
2176        -C option of pcretest uses this to show which version is compiled.
2178        A new data escape \S, is added to pcretest; it causes the amounts of store
2179        obtained and freed by both kinds of malloc/free at match time to be added
2180        to the output.
2182     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2183        what's available on my current Linux desktop machine.
2185     3. When matching a UTF-8 string, the test for a valid string at the start has
2186        been extended. If start_offset is not zero, PCRE now checks that it points
2187        to a byte that is the start of a UTF-8 character. If not, it returns
2188        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2189        this is necessary because there may be backward assertions in the pattern.
2190        When matching the same subject several times, it may save resources to use
2191        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2193     4. The code for checking the validity of UTF-8 strings has been tightened so
2194        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2195        containing "overlong sequences".
2197     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2198        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2199        should have been "&", but it just so happened that all the cases this let
2200        through by mistake were picked up later in the function.
2202     6. I had used a variable called "isblank" - this is a C99 function, causing
2203        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2205     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2206        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2207        so the version is shown; (c) stop "make test" echoing "./RunTest".
2209     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2211     9. The prototype for memmove() for systems that don't have it was using
2212        size_t, but the inclusion of the header that defines size_t was later. I've
2213        moved the #includes for the C headers earlier to avoid this.
2215    10. Added some adjustments to the code to make it easier to compiler on certain
2216        special systems:
2218          (a) Some "const" qualifiers were missing.
2219          (b) Added the macro EXPORT before all exported functions; by default this
2220              is defined to be empty.
2221          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2222              that it reads its output file name as an argument instead of writing
2223              to the standard output and assuming this can be redirected.
2225    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2226        class containing characters with values greater than 255, PCRE compilation
2227        went into a loop.
2229    12. A recursive reference to a subpattern that was within another subpattern
2230        that had a minimum quantifier of zero caused PCRE to crash. For example,
2231        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2232        recursion. If the recursively-called subpattern itself had a zero repeat,
2233        that was OK.
2235    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2236        buffer into which it was copied (for escape processing) was still set at
2237        1024, so long lines caused crashes.
2239    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2240        "internal error: code overflow...". This applied to any character class
2241        that was followed by a possessive quantifier.
2243    15. Modified the Makefile to add libpcre.la as a prerequisite for
2244        libpcreposix.la because I was told this is needed for a parallel build to
2245        work.
2247    16. If a pattern that contained .* following optional items at the start was
2248        studied, the wrong optimizing data was generated, leading to matching
2249        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2250        matching string must start with a or b or c. The correct conclusion for
2251        this pattern is that a match can start with any character.
2254    Version 4.4 13-Aug-03
2255    ---------------------
2257     1. In UTF-8 mode, a character class containing characters with values between
2258        127 and 255 was not handled correctly if the compiled pattern was studied.
2259        In fixing this, I have also improved the studying algorithm for such
2260        classes (slightly).
2262     2. Three internal functions had redundant arguments passed to them. Removal
2263        might give a very teeny performance improvement.
2265     3. Documentation bug: the value of the capture_top field in a callout is *one
2266        more than* the number of the hightest numbered captured substring.
2268     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2269        in incorrectly linking with a previously installed version. They now link
2270        explicitly with libpcre.la.
2272     5. configure.in no longer needs to recognize Cygwin specially.
2274     6. A problem in pcre.in for Windows platforms is fixed.
2276     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2277        pcretest, it used to include the size of the study block as part of its
2278        output. Unfortunately, the structure contains a field that has a different
2279        size on different hardware architectures. This meant that the tests that
2280        showed this size failed. As the block is currently always of a fixed size,
2281        this information isn't actually particularly useful in pcretest output, so
2282        I have just removed it.
2284     8. Three pre-processor statements accidentally did not start in column 1.
2285        Sadly, there are *still* compilers around that complain, even though
2286        standard C has not required this for well over a decade. Sigh.
2288     9. In pcretest, the code for checking callouts passed small integers in the
2289        callout_data field, which is a void * field. However, some picky compilers
2290        complained about the casts involved for this on 64-bit systems. Now
2291        pcretest passes the address of the small integer instead, which should get
2292        rid of the warnings.
2294    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2295        both compile and run time, and gives an error if an invalid UTF-8 sequence
2296        is found. There is a option for disabling this check in cases where the
2297        string is known to be correct and/or the maximum performance is wanted.
2299    11. In response to a bug report, I changed one line in Makefile.in from
2301            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2302        to
2303            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2305        to look similar to other lines, but I have no way of telling whether this
2306        is the right thing to do, as I do not use Windows. No doubt I'll get told
2307        if it's wrong...
2310    Version 4.3 21-May-03
2311    ---------------------
2313    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2314       Makefile.
2316    2. Some refactoring to improve the quality of the code:
2318       (i)   The utf8_table... variables are now declared "const".
2320       (ii)  The code for \cx, which used the "case flipping" table to upper case
2321             lower case letters, now just substracts 32. This is ASCII-specific,
2322             but the whole concept of \cx is ASCII-specific, so it seems
2323             reasonable.
2325       (iii) PCRE was using its character types table to recognize decimal and
2326             hexadecimal digits in the pattern. This is silly, because it handles
2327             only 0-9, a-f, and A-F, but the character types table is locale-
2328             specific, which means strange things might happen. A private
2329             table is now used for this - though it costs 256 bytes, a table is
2330             much faster than multiple explicit tests. Of course, the standard
2331             character types table is still used for matching digits in subject
2332             strings against \d.
2334       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2335             ending in _t are). So I've renamed it as ESC_tee.
2337    3. The first argument for regexec() in the POSIX wrapper should have been
2338       defined as "const".
2340    4. Changed pcretest to use malloc() for its buffers so that they can be
2341       Electric Fenced for debugging.
2343    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2344       to read one or more bytes before the start of the subject string. Often this
2345       had no effect on PCRE's behaviour, but in some circumstances it could
2346       provoke a segmentation fault.
2348    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2349       to try to read one or more bytes before the start of the subject string.
2351    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2352       UTF-8 support could misbehave in various ways if the subject string
2353       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2354       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2355       back over UTF-8 characters.)
2358    Version 4.2 14-Apr-03
2359    ---------------------
2361    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2363    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2364         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2365         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2366         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2367         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2368           and BUILD_EXEEXT
2369         Note: automatic setting of the BUILD variables is not yet working
2370         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2371           compile-time but not at link-time
2372         [LINK]: use for linking executables only
2373         make different versions for Windows and non-Windows
2374         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2375           libraries
2376         [LINK_FOR_BUILD]: new variable
2377         [OBJEXT]: use throughout
2378         [EXEEXT]: use throughout
2379         <winshared>: new target
2380         <wininstall>: new target
2381         <dftables.o>: use native compiler
2382         <dftables>: use native linker
2383         <install>: handle Windows platform correctly
2384         <clean>: ditto
2385         <check>: ditto
2386         copy DLL to top builddir before testing
2388       As part of these changes, -no-undefined was removed again. This was reported
2389       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2390       in any case.
2392    3. Some tidies to get rid of compiler warnings:
2394       . In the match_data structure, match_limit was an unsigned long int, whereas
2395         match_call_count was an int. I've made them both unsigned long ints.
2397       . In pcretest the fact that a const uschar * doesn't automatically cast to
2398         a void * provoked a warning.
2400       . Turning on some more compiler warnings threw up some "shadow" variables
2401         and a few more missing casts.
2403    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2404       option, a class that contained a single character with a value between 128
2405       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2407    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2408       option, a class that contained several characters, but with at least one
2409       whose value was between 128 and 255 caused PCRE to crash.
2412    Version 4.1 12-Mar-03
2413    ---------------------
2415    1. Compiling with gcc -pedantic found a couple of places where casts were
2416    needed, and a string in dftables.c that was longer than standard compilers are
2417    required to support.
2419    2. Compiling with Sun's compiler found a few more places where the code could
2420    be tidied up in order to avoid warnings.
2422    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2423    first of these names is deprecated in the latest Autoconf in favour of the name
2424    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2425    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2426    analogy I have changed it to CFLAGS_FOR_BUILD.
2428    4. Added -no-undefined to the linking command in the Makefile, because this is
2429    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2430    linking step for the pcreposix library.
2432    5. PCRE was failing to diagnose the case of two named groups with the same
2433    name.
2435    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2436    literal character that is needed in the subject for a match, and scans along to
2437    ensure that it is present before embarking on the full matching process. This
2438    saves time in cases of nested unlimited repeats that are never going to match.
2439    Problem: the scan can take a lot of time if the subject is very long (e.g.
2440    megabytes), thus penalizing straightforward matches. It is now done only if the
2441    amount of subject to be scanned is less than 1000 bytes.
2443    7. A lesser problem with the same optimization is that it was recording the
2444    first character of an anchored pattern as "needed", thus provoking a search
2445    right along the subject, even when the first match of the pattern was going to
2446    fail. The "needed" character is now not set for anchored patterns, unless it
2447    follows something in the pattern that is of non-fixed length. Thus, it still
2448    fulfils its original purpose of finding quick non-matches in cases of nested
2449    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2452    Version 4.0 17-Feb-03
2453    ---------------------
2455    1. If a comment in an extended regex that started immediately after a meta-item
2456    extended to the end of string, PCRE compiled incorrect data. This could lead to
2457    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2459    2. Moved to autoconf 2.53 and libtool 1.4.2.
2461    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2462    the special perltest8 script is no longer needed - all the tests can be run
2463    from a single perltest script.
2465    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2466    by \s. It has now been removed in PCRE. This means it isn't recognized as
2467    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2468    class [:space:] *does* include VT, thereby creating a mess.
2470    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2471    space and tab.
2473    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2474    its new features into the main test script, reducing the number of scripts.
2476    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2477    were backward compatible, and made the (?i) apply to the whole pattern, as if
2478    /i were given. Now it behaves more logically, and applies the option setting
2479    only to what follows. PCRE has been changed to follow suit. However, if it
2480    finds options settings right at the start of the pattern, it extracts them into
2481    the global options, as before. Thus, they show up in the info data.
2483    8. Added support for the \Q...\E escape sequence. Characters in between are
2484    treated as literals. This is slightly different from Perl in that $ and @ are
2485    also handled as literals inside the quotes. In Perl, they will cause variable
2486    interpolation. Note the following examples:
2488        Pattern            PCRE matches      Perl matches
2490        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
2491        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
2492        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
2494    For compatibility with Perl, \Q...\E sequences are recognized inside character
2495    classes as well as outside them.
2497    9. Re-organized 3 code statements in pcretest to avoid "overflow in
2498    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2499    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2500    signed/unsigned warnings.
2502    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2503    option for pcretest, so I've replaced it by a simple function that does just
2504    that job.
2506    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2507    "pcregrep -".
2509    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2510    Java package. This provides some syntactic sugar for simple cases of what my
2511    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2512    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2513    item, you can use this simplified notation. Note that only makes sense with
2514    greedy quantifiers. Consequently, the use of the possessive quantifier forces
2515    greediness, whatever the setting of the PCRE_UNGREEDY option.
2517    13. A change of greediness default within a pattern was not taking effect at
2518    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2519    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2520    was abstracted outside.
2522    14. PCRE now supports the \G assertion. It is true when the current matching
2523    position is at the start point of the match. This differs from \A when the
2524    starting offset is non-zero. Used with the /g option of pcretest (or similar
2525    code), it works in the same way as it does for Perl's /g option. If all
2526    alternatives of a regex begin with \G, the expression is anchored to the start
2527    match position, and the "anchored" flag is set in the compiled expression.
2529    15. Some bugs concerning the handling of certain option changes within patterns
2530    have been fixed. These applied to options other than (?ims). For example,
2531    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2532    been the other way round. Some of this was related to change 7 above.
2534    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2535    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2536    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2537    POSIX classes only within a class (e.g. /[[:alpha:]]/).
2539    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2540    mode. Unlike ".", it always matches newline, whatever the setting of
2541    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2542    assertions. Perl allows it, but it doesn't (in general) work because it can't
2543    calculate the length of the lookbehind. At least, that's the case for Perl
2544    5.8.0 - I've been told they are going to document that it doesn't work in
2545    future.
2547    18. Added an error diagnosis for escapes that PCRE does not support: these are
2548    \L, \l, \N, \P, \p, \U, \u, and \X.
2550    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2551    reading past the end of the pattern in cases such as /[abcd/.
2553    20. PCRE was getting more memory than necessary for patterns with classes that
2554    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2556    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2557    compiling PCRE for use with Virtual Pascal.
2559    22. Small fix to the Makefile to make it work properly if the build is done
2560    outside the source tree.
2562    23. Added a new extension: a condition to go with recursion. If a conditional
2563    subpattern starts with (?(R) the "true" branch is used if recursion has
2564    happened, whereas the "false" branch is used only at the top level.
2566    24. When there was a very long string of literal characters (over 255 bytes
2567    without UTF support, over 250 bytes with UTF support), the computation of how
2568    much memory was required could be incorrect, leading to segfaults or other
2569    strange effects.
2571    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2572    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2573    there was a subsequent back reference to those brackets. This meant that, for
2574    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2575    possible to check for precisely this case. All we can do is abandon the
2576    optimization if .* occurs inside capturing brackets when there are any back
2577    references whatsoever. (See below for a better fix that came later.)
2579    26. The handling of the optimization for finding the first character of a
2580    non-anchored pattern, and for finding a character that is required later in the
2581    match were failing in some cases. This didn't break the matching; it just
2582    failed to optimize when it could. The way this is done has been re-implemented.
2584    27. Fixed typo in error message for invalid (?R item (it said "(?p").
2586    28. Added a new feature that provides some of the functionality that Perl
2587    provides with (?{...}). The facility is termed a "callout". The way it is done
2588    in PCRE is for the caller to provide an optional function, by setting
2589    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2590    global variable. By default it is unset, which disables all calling out. To get
2591    the function called, the regex must include (?C) at appropriate points. This
2592    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2593    This provides a means of identifying different callout points. When PCRE
2594    reaches such a point in the regex, if pcre_callout has been set, the external
2595    function is called. It is provided with data in a structure called
2596    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2597    matching continues; if it returns a non-zero value, the match at the current
2598    point fails. However, backtracking will occur if possible. [This was changed
2599    later and other features added - see item 49 below.]
2601    29. pcretest is upgraded to test the callout functionality. It provides a
2602    callout function that displays information. By default, it shows the start of
2603    the match and the current position in the text. There are some new data escapes
2604    to vary what happens:
2606        \C+         in addition, show current contents of captured substrings
2607        \C-         do not supply a callout function
2608        \C!n        return 1 when callout number n is reached
2609        \C!n!m      return 1 when callout number n is reached for the mth time
2611    30. If pcregrep was called with the -l option and just a single file name, it
2612    output "<stdin>" if a match was found, instead of the file name.
2614    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2615    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2616    pcre_exec(). This saves a malloc/free per call. The default value of
2617    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2618    when configuring.
2620    32. The default maximum size of a compiled pattern is 64K. There have been a
2621    few cases of people hitting this limit. The code now uses macros to handle the
2622    storing of links as offsets within the compiled pattern. It defaults to 2-byte
2623    links, but this can be changed to 3 or 4 bytes by --with-link-size when
2624    configuring. Tests 2 and 5 work only with 2-byte links because they output
2625    debugging information about compiled patterns.
2627    33. Internal code re-arrangements:
2629    (a) Moved the debugging function for printing out a compiled regex into
2630        its own source file (printint.c) and used #include to pull it into
2631        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2632        separate copies.
2634    (b) Defined the list of op-code names for debugging as a macro in
2635        internal.h so that it is next to the definition of the opcodes.
2637    (c) Defined a table of op-code lengths for simpler skipping along compiled
2638        code. This is again a macro in internal.h so that it is next to the
2639        definition of the opcodes.
2641    34. Added support for recursive calls to individual subpatterns, along the
2642    lines of Robin Houston's patch (but implemented somewhat differently).
2644    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2645    allow it to read and process whole directories in Win32. This code was
2646    contributed by Lionel Fourquaux; it has not been tested by me.
2648    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2649    used to name a group. Names consist of alphanumerics and underscores, and must
2650    be unique. Back references use the syntax (?P=name) and recursive calls use
2651    (?P>name) which is a PCRE extension to the Python extension. Groups still have
2652    numbers. The function pcre_fullinfo() can be used after compilation to extract
2653    a name/number map. There are three relevant calls:
2655      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
2656      PCRE_INFO_NAMECOUNT            yields the number of entries
2657      PCRE_INFO_NAMETABLE            yields a pointer to the map.
2659    The map is a vector of fixed-size entries. The size of each entry depends on
2660    the length of the longest name used. The first two bytes of each entry are the
2661    group number, most significant byte first. There follows the corresponding
2662    name, zero terminated. The names are in alphabetical order.
2664    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2665    case instead of 255. Making it the same both with and without UTF-8 support
2666    means that the same test output works with both.
2668    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2669    calling malloc() with a zero argument.
2671    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2672    optimization. I've improved things by keeping a bitmap of backreferences with
2673    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2674    fact referenced, the optimization can be applied. It is unlikely that a
2675    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2676    the match to follow \n) will appear inside brackets with a number greater than
2677    31, but if it does, any back reference > 31 suppresses the optimization.
2679    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2680    of disabling numbered capturing parentheses. Any opening parenthesis that is
2681    not followed by ? behaves as if it were followed by ?: but named parentheses
2682    can still be used for capturing (and they will acquire numbers in the usual
2683    way).
2685    41. Redesigned the return codes from the match() function into yes/no/error so
2686    that errors can be passed back from deep inside the nested calls. A malloc
2687    failure while inside a recursive subpattern call now causes the
2688    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2690    42. It is now possible to set a limit on the number of times the match()
2691    function is called in a call to pcre_exec(). This facility makes it possible to
2692    limit the amount of recursion and backtracking, though not in a directly
2693    obvious way, because the match() function is used in a number of different
2694    circumstances. The count starts from zero for each position in the subject
2695    string (for non-anchored patterns). The default limit is, for compatibility, a
2696    large number, namely 10 000 000. You can change this in two ways:
2698    (a) When configuring PCRE before making, you can use --with-match-limit=n
2699        to set a default value for the compiled library.
2701    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2702        a different value is set. See 45 below.
2704    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2706    43. Added a new function pcre_config(int, void *) to enable run-time extraction
2707    of things that can be changed at compile time. The first argument specifies
2708    what is wanted and the second points to where the information is to be placed.
2709    The current list of available information is:
2711      PCRE_CONFIG_UTF8
2713    The output is an integer that is set to one if UTF-8 support is available;
2714    otherwise it is set to zero.
2718    The output is an integer that it set to the value of the code that is used for
2719    newline. It is either LF (10) or CR (13).
2723    The output is an integer that contains the number of bytes used for internal
2724    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2728    The output is an integer that contains the threshold above which the POSIX
2729    interface uses malloc() for output vectors. See item 31 above.
2733    The output is an unsigned integer that contains the default limit of the number
2734    of match() calls in a pcre_exec() execution. See 42 above.
2736    44. pcretest has been upgraded by the addition of the -C option. This causes it
2737    to extract all the available output from the new pcre_config() function, and to
2738    output it. The program then exits immediately.
2740    45. A need has arisen to pass over additional data with calls to pcre_exec() in
2741    order to support additional features. One way would have been to define
2742    pcre_exec2() (for example) with extra arguments, but this would not have been
2743    extensible, and would also have required all calls to the original function to
2744    be mapped to the new one. Instead, I have chosen to extend the mechanism that
2745    is used for passing in "extra" data from pcre_study().
2747    The pcre_extra structure is now exposed and defined in pcre.h. It currently
2748    contains the following fields:
2750      flags         a bitmap indicating which of the following fields are set
2751      study_data    opaque data from pcre_study()
2752      match_limit   a way of specifying a limit on match() calls for a specific
2753                      call to pcre_exec()
2754      callout_data  data for callouts (see 49 below)
2756    The flag bits are also defined in pcre.h, and are
2762    The pcre_study() function now returns one of these new pcre_extra blocks, with
2763    the actual study data pointed to by the study_data field, and the
2764    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2765    before. That is, this change is entirely upwards-compatible and requires no
2766    change to existing code.
2768    If you want to pass in additional data to pcre_exec(), you can either place it
2769    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2770    block.
2772    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2773    data string contains the escape sequence \M, pcretest calls pcre_exec() several
2774    times with different match limits, until it finds the minimum value needed for
2775    pcre_exec() to complete. The value is then output. This can be instructive; for
2776    most simple matches the number is quite small, but for pathological cases it
2777    gets very large very quickly.
2779    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2780    returns the size of the data block pointed to by the study_data field in a
2781    pcre_extra block, that is, the value that was passed as the argument to
2782    pcre_malloc() when PCRE was getting memory in which to place the information
2783    created by pcre_study(). The fourth argument should point to a size_t variable.
2784    pcretest has been extended so that this information is shown after a successful
2785    pcre_study() call when information about the compiled regex is being displayed.
2787    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2788    because what follows is always an absolute path. (Later: it turns out that this
2789    is more than cosmetic for MinGW, because it doesn't like empty path
2790    components.)
2792    49. Some changes have been made to the callout feature (see 28 above):
2794    (i)  A callout function now has three choices for what it returns:
2796           0  =>  success, carry on matching
2797         > 0  =>  failure at this point, but backtrack if possible
2798         < 0  =>  serious error, return this value from pcre_exec()
2800         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2801         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2802         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2803         use by callout functions. It will never be used by PCRE itself.
2805    (ii) The pcre_extra structure (see 45 above) has a void * field called
2806         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2807         pcre_callout_block structure has a field of the same name. The contents of
2808         the field passed in the pcre_extra structure are passed to the callout
2809         function in the corresponding field in the callout block. This makes it
2810         easier to use the same callout-containing regex from multiple threads. For
2811         testing, the pcretest program has a new data escape
2813           \C*n        pass the number n (may be negative) as callout_data
2815         If the callout function in pcretest receives a non-zero value as
2816         callout_data, it returns that value.
2818    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2819    there were some redundant $(CFLAGS) in commands that are now specified as
2820    $(LINK), which already includes $(CFLAGS).
2822    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2823    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2824    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2825    one-byte characters throughout. Note that case-insensitive matching applies
2826    only to characters whose values are less than 256. PCRE doesn't support the
2827    notion of cases for higher-valued characters.
2829    (i)   A character class whose characters are all within 0-255 is handled as
2830          a bit map, and the map is inverted for negative classes. Previously, a
2831          character > 255 always failed to match such a class; however it should
2832          match if the class was a negative one (e.g. [^ab]). This has been fixed.
2834    (ii)  A negated character class with a single character < 255 is coded as
2835          "not this character" (OP_NOT). This wasn't working properly when the test
2836          character was multibyte, either singly or repeated.
2838    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2839          mode, for example: \x{100}{2,3}.
2841    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2842          singly or repeated) now correctly test multibyte characters. However,
2843          PCRE doesn't recognize any characters with values greater than 255 as
2844          digits, spaces, or word characters. Such characters always match \D, \S,
2845          and \W, and never match \d, \s, or \w.
2847    (v)   Classes may now contain characters and character ranges with values
2848          greater than 255. For example: [ab\x{100}-\x{400}].
2850    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
2851          PCRE in UTF-8 mode.
2853    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2854    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2855    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2856    value.)
2858    53. The single man page has become too large. I have therefore split it up into
2859    a number of separate man pages. These also give rise to individual HTML pages;
2860    these are now put in a separate directory, and there is an index.html page that
2861    lists them all. Some hyperlinking between the pages has been installed.
2863    54. Added convenience functions for handling named capturing parentheses.
2865    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2866    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2867    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2868    are faulted.
2870    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2871    calling configure. These values are used when compiling the dftables.c program
2872    which is run to generate the source of the default character tables. They
2873    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2874    you will need to set these values.
2876    57. Updated the building process for Windows DLL, as provided by Fred Cox.
2879    Version 3.9 02-Jan-02
2880    ---------------------
2882    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2884    2. If --disable-static was given, the building process failed when trying to
2885    build pcretest and pcregrep. (For some reason it was using libtool to compile
2886    them, which is not right, as they aren't part of the library.)
2889    Version 3.8 18-Dec-01
2890    ---------------------
2892    1. The experimental UTF-8 code was completely screwed up. It was packing the
2893    bytes in the wrong order. How dumb can you get?
2896    Version 3.7 29-Oct-01
2897    ---------------------
2899    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2900    This caused pcretest, when used on the test data, to segfault. Unfortunately,
2901    this didn't happen under Solaris 8, where I normally test things.
2903    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2904    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2905    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2906    this fix an hour or so after the initial 3.7 release.)
2909    Version 3.6 23-Oct-01
2910    ---------------------
2912    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2913    offsets passed as NULL with zero offset count.
2915    2. The config.guess and config.sub files had not been updated when I moved to
2916    the latest autoconf.
2919    Version 3.5 15-Aug-01
2920    ---------------------
2922    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2923    had been forgotten.
2925    2. By using declared but undefined structures, we can avoid using "void"
2926    definitions in pcre.h while keeping the internal definitions of the structures
2927    private.
2929    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2930    user point of view, this means that both static and shared libraries are built
2931    by default, but this can be individually controlled. More of the work of
2932    handling this static/shared cases is now inside libtool instead of PCRE's make
2933    file.
2935    4. The pcretest utility is now installed along with pcregrep because it is
2936    useful for users (to test regexs) and by doing this, it automatically gets
2937    relinked by libtool. The documentation has been turned into a man page, so
2938    there are now .1, .txt, and .html versions in /doc.
2940    5. Upgrades to pcregrep:
2941       (i)   Added long-form option names like gnu grep.
2942       (ii)  Added --help to list all options with an explanatory phrase.
2943       (iii) Added -r, --recursive to recurse into sub-directories.
2944       (iv)  Added -f, --file to read patterns from a file.
2946    6. pcre_exec() was referring to its "code" argument before testing that
2947    argument for NULL (and giving an error if it was NULL).
2949    7. Upgraded Makefile.in to allow for compiling in a different directory from
2950    the source directory.
2952    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2953    options bits, the pointer it was passed was to an int instead of to an unsigned
2954    long int. This mattered only on 64-bit systems.
2956    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2957    generated) instead of pcre.in, which it its source. Also made the same change
2958    in several of the .c files.
2960    10. A new release of gcc defines printf() as a macro, which broke pcretest
2961    because it had an ifdef in the middle of a string argument for printf(). Fixed
2962    by using separate calls to printf().
2964    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2965    script, to force use of CR or LF instead of \n in the source. On non-Unix
2966    systems, the value can be set in config.h.
2968    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2969    absolute limit. Changed the text of the error message to make this clear, and
2970    likewise updated the man page.
2972    13. The limit of 99 on the number of capturing subpatterns has been removed.
2973    The new limit is 65535, which I hope will not be a "real" limit.
2976    Version 3.4 22-Aug-00
2977    ---------------------
2979    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2981    2. Diagnose condition (?(0) as an error instead of crashing on matching.
2984  Version 3.3 01-Aug-00  Version 3.3 01-Aug-00
2985  ---------------------  ---------------------

Removed from v.49  
changed lines
  Added in v.442

  ViewVC Help
Powered by ViewVC 1.1.5