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revision 33 by nigel, Sat Feb 24 21:39:01 2007 UTC revision 419 by ph10, Wed Aug 12 10:45:33 2009 UTC
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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8        was out-of-date, and there was no check on the pcre_compile() error code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.
17    Version 7.9 11-Apr-09
18    ---------------------
20    1.  When building with support for bzlib/zlib (pcregrep) and/or readline
21        (pcretest), all targets were linked against these libraries. This included
22        libpcre, libpcreposix, and libpcrecpp, even though they do not use these
23        libraries. This caused unwanted dependencies to be created. This problem
24        has been fixed, and now only pcregrep is linked with bzlib/zlib and only
25        pcretest is linked with readline.
27    2.  The "typedef int BOOL" in pcre_internal.h that was included inside the
28        "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
29        moved outside it again, because FALSE and TRUE are already defined in AIX,
30        but BOOL is not.
32    3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
33        PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
35    4.  The pcregrep documentation said spaces were inserted as well as colons (or
36        hyphens) following file names and line numbers when outputting matching
37        lines. This is not true; no spaces are inserted. I have also clarified the
38        wording for the --colour (or --color) option.
40    5.  In pcregrep, when --colour was used with -o, the list of matching strings
41        was not coloured; this is different to GNU grep, so I have changed it to be
42        the same.
44    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
45        each matching line was coloured. Now it goes on to look for further matches
46        of any of the test patterns, which is the same behaviour as GNU grep.
48    7.  A pattern that could match an empty string could cause pcregrep to loop; it
49        doesn't make sense to accept an empty string match in pcregrep, so I have
50        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
51        seems to be how GNU grep behaves.
53    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
54        start or after a newline", because the conditional assertion was not being
55        correctly handled. The rule now is that both the assertion and what follows
56        in the first alternative must satisfy the test.
58    9.  If auto-callout was enabled in a pattern with a conditional group whose
59        condition was an assertion, PCRE could crash during matching, both with
60        pcre_exec() and pcre_dfa_exec().
62    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
63        used for matching.
65    11. Unicode property support in character classes was not working for
66        characters (bytes) greater than 127 when not in UTF-8 mode.
68    12. Added the -M command line option to pcretest.
70    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
72    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
74    16. Added comments and documentation about mis-use of no_arg in the C++
75        wrapper.
77    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
78        from Martin Jerabek that uses macro names for all relevant character and
79        string constants.
81    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
82        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
83        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
84        these, but not everybody uses configure.
86    19. A conditional group that had only one branch was not being correctly
87        recognized as an item that could match an empty string. This meant that an
88        enclosing group might also not be so recognized, causing infinite looping
89        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
90        with the subject "ab", where knowledge that the repeated group can match
91        nothing is needed in order to break the loop.
93    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
94        exec(), but without supplying a callout function, matching went wrong.
96    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
97        leak if the size of the offset vector was greater than 30. When the vector
98        is smaller, the saved offsets during recursion go onto a local stack
99        vector, but for larger vectors malloc() is used. It was failing to free
100        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
101        error, in fact).
103    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
104        heapframe that is used only when UTF-8 support is enabled. This caused no
105        problem, but was untidy.
107    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
108        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
109        included within another project.
111    24. Steven Van Ingelgem's patches to add more options to the CMake support,
112        slightly modified by me:
114          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
115              not building pcregrep.
117          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
118              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
120    25. Forward references, both numeric and by name, in patterns that made use of
121        duplicate group numbers, could behave incorrectly or give incorrect errors,
122        because when scanning forward to find the reference group, PCRE was not
123        taking into account the duplicate group numbers. A pattern such as
124        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
126    26. Changed a few more instances of "const unsigned char *" to USPTR, making
127        the feature of a custom pointer more persuasive (as requested by a user).
129    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
130        pcretest.c, inside #ifndefs, because it seems they are sometimes already
131        pre-defined.
133    28. Added support for (*UTF8) at the start of a pattern.
135    29. Arrange for flags added by the "release type" setting in CMake to be shown
136        in the configuration summary.
139    Version 7.8 05-Sep-08
140    ---------------------
142    1.  Replaced UCP searching code with optimized version as implemented for Ad
143        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
144        stage table and inline lookup instead of a function, giving speed ups of 2
145        to 5 times on some simple patterns that I tested. Permission was given to
146        distribute the MultiStage2.py script that generates the tables (it's not in
147        the tarball, but is in the Subversion repository).
149    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
150        scripts.
152    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
153        a group with a zero qualifier. The result of the study could be incorrect,
154        or the function might crash, depending on the pattern.
156    4.  Caseless matching was not working for non-ASCII characters in back
157        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
158        It now works when Unicode Property Support is available.
160    5.  In pcretest, an escape such as \x{de} in the data was always generating
161        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
162        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
163        truncation.
165    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
167    7.  Added two (int) casts to pcregrep when printing the difference of two
168        pointers, in case they are 64-bit values.
170    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
171        test 2 if it fails.
173    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
174        and a #define of that name to empty if it is not externally set. This is to
175        allow users of MSVC to set it if necessary.
177    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
178        the convenience functions in the pcre_get.c source file.
180    11. An option change at the start of a pattern that had top-level alternatives
181        could cause overwriting and/or a crash. This command provoked a crash in
182        some environments:
184          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
186        This potential security problem was recorded as CVE-2008-2371.
188    12. For a pattern where the match had to start at the beginning or immediately
189        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
190        pcre_dfa_exec() could read past the end of the passed subject if there was
191        no match. To help with detecting such bugs (e.g. with valgrind), I modified
192        pcretest so that it places the subject at the end of its malloc-ed buffer.
194    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
195        exec() might read past the end of the data buffer in UTF-8 mode.
197    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
198        the data contained the byte 0x85 as part of a UTF-8 character within its
199        first line. This applied both to normal and DFA matching.
201    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
202        /^[^d]*?$/8 failed to match "abc".
204    16. Added a missing copyright notice to pcrecpp_internal.h.
206    17. Make it more clear in the documentation that values returned from
207        pcre_exec() in ovector are byte offsets, not character counts.
209    18. Tidied a few places to stop certain compilers from issuing warnings.
211    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
212        supplied by Stefan Weber. I made a further small update for 7.8 because
213        there is a change of source arrangements: the pcre_searchfuncs.c module is
214        replaced by pcre_ucd.c.
217    Version 7.7 07-May-08
218    ---------------------
220    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
221        a string to a long long, pretend we don't even have a long long." This is
222        done by checking for the strtoq, strtoll, and _strtoi64 functions.
224    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
225        pre-7.6 versions, which defined a global no_arg variable instead of putting
226        it in the RE class. (See also #8 below.)
228    3.  Remove a line of dead code, identified by coverity and reported by Nuno
229        Lopes.
231    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
233        (1) The include/exclude patterns were being applied to the whole pathnames
234            of files, instead of just to the final components.
236        (2) If there was more than one level of directory, the subdirectories were
237            skipped unless they satisfied the include/exclude conditions. This is
238            inconsistent with GNU grep (and could even be seen as contrary to the
239            pcregrep specification - which I improved to make it absolutely clear).
240            The action now is always to scan all levels of directory, and just
241            apply the include/exclude patterns to regular files.
243    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
244        --exclude_dir in the tests to avoid scanning .svn directories.
246    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
247        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
248        doesn't support NULs in patterns.
250    7.  Added some missing "const"s to declarations of static tables in
251        pcre_compile.c and pcre_dfa_exec.c.
253    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
254        caused by fix #2  above. (Subsequently also a second patch to fix the
255        first patch. And a third patch - this was a messy problem.)
257    9.  Applied Craig's patch to remove the use of push_back().
259    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
260        matching function regexec().
262    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
263        which, however, unlike Perl's \g{...}, are subroutine calls, not back
264        references. PCRE supports relative numbers with this syntax (I don't think
265        Oniguruma does).
267    12. Previously, a group with a zero repeat such as (...){0} was completely
268        omitted from the compiled regex. However, this means that if the group
269        was called as a subroutine from elsewhere in the pattern, things went wrong
270        (an internal error was given). Such groups are now left in the compiled
271        pattern, with a new opcode that causes them to be skipped at execution
272        time.
274    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
275        to the way PCRE behaves:
277        (a) A lone ] character is dis-allowed (Perl treats it as data).
279        (b) A back reference to an unmatched subpattern matches an empty string
280            (Perl fails the current match path).
282        (c) A data ] in a character class must be notated as \] because if the
283            first data character in a class is ], it defines an empty class. (In
284            Perl it is not possible to have an empty class.) The empty class []
285            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
286            The negative empty class [^] matches any one character, independently
287            of the DOTALL setting.
289    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
290        non-existent subpattern following a character class starting with ']' and
291        containing () gave an internal compiling error instead of "reference to
292        non-existent subpattern". Fortunately, when the pattern did exist, the
293        compiled code was correct. (When scanning forwards to check for the
294        existencd of the subpattern, it was treating the data ']' as terminating
295        the class, so got the count wrong. When actually compiling, the reference
296        was subsequently set up correctly.)
298    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
299        it was being rejected as not supported by pcre_dfa_exec(), even though
300        other assertions are supported. I have made pcre_dfa_exec() support
301        (*FAIL).
303    16. The implementation of 13c above involved the invention of a new opcode,
304        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
305        cannot be changed at match time, I realized I could make a small
306        improvement to matching performance by compiling OP_ALLANY instead of
307        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
308        on the OP_ANY path.
310    17. Compiling pcretest on Windows with readline support failed without the
311        following two fixes: (1) Make the unistd.h include conditional on
312        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
314    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
315        ncurses library to be included for pcretest when ReadLine support is
316        requested, but also to allow for it to be overridden. This patch came from
317        Daniel Bergström.
319    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
320        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
321        any errors with the current Unicode tables. Thanks to Peter Kankowski for
322        spotting this.
325    Version 7.6 28-Jan-08
326    ---------------------
328    1.  A character class containing a very large number of characters with
329        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
330        overflow.
332    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
333        HAVE_LONG_LONG is not defined.
335    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
336        bring them up to date and include new features. This patch includes:
338        - Fixed PH's badly added libz and libbz2 support.
339        - Fixed a problem with static linking.
340        - Added pcredemo. [But later removed - see 7 below.]
341        - Fixed dftables problem and added an option.
342        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
343            HAVE_LONG_LONG.
344        - Added readline support for pcretest.
345        - Added an listing of the option settings after cmake has run.
347    4.  A user submitted a patch to Makefile that makes it easy to create
348        "pcre.dll" under mingw when using Configure/Make. I added stuff to
349        Makefile.am that cause it to include this special target, without
350        affecting anything else. Note that the same mingw target plus all
351        the other distribution libraries and programs are now supported
352        when configuring with CMake (see 6 below) instead of with
353        Configure/Make.
355    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
356        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
357        exported in the Windows port". It has not yet been confirmed that the patch
358        solves the problem, but it does no harm.
360    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
361        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
362        with CMake, and also correct the comment about stack recursion.
364    7.  Remove the automatic building of pcredemo from the ./configure system and
365        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
366        of a program that users should build themselves after PCRE is installed, so
367        building it automatically is not really right. What is more, it gave
368        trouble in some build environments.
370    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
373    Version 7.5 10-Jan-08
374    ---------------------
376    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
377        values in parens when parsing an RE using the C++ wrapper."
379    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
380        Characters greater than 255 were excluded from the class instead of being
381        included.
383    3.  The same bug as (2) above applied to negated POSIX classes such as
384        [:^space:].
386    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
387        defined or documented. It seems to have been a typo for PCRE_STATIC, so
388        I have changed it.
390    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
391        first named subpattern) and a construct such as (?&a) would reference the
392        first named subpattern whose name started with "a" (in other words, the
393        length check was missing). Both these problems are fixed. "Subpattern name
394        expected" is now given for (?&) (a zero-length name), and this patch also
395        makes it give the same error for \k'' (previously it complained that that
396        was a reference to a non-existent subpattern).
398    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
399        this is right because (?- can be followed by option settings as well as by
400        digits. I have, however, made the messages clearer.
402    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
403        than the number used in the conditional) now cause a compile-time error.
404        This is actually not compatible with Perl, which accepts such patterns, but
405        treats the conditional as always being FALSE (as PCRE used to), but it
406        seems to me that giving a diagnostic is better.
408    8.  Change "alphameric" to the more common word "alphanumeric" in comments
409        and messages.
411    9.  Fix two occurrences of "backslash" in comments that should have been
412        "backspace".
414    10. Remove two redundant lines of code that can never be obeyed (their function
415        was moved elsewhere).
417    11. The program that makes PCRE's Unicode character property table had a bug
418        which caused it to generate incorrect table entries for sequences of
419        characters that have the same character type, but are in different scripts.
420        It amalgamated them into a single range, with the script of the first of
421        them. In other words, some characters were in the wrong script. There were
422        thirteen such cases, affecting characters in the following ranges:
424          U+002b0 - U+002c1
425          U+0060c - U+0060d
426          U+0061e - U+00612
427          U+0064b - U+0065e
428          U+0074d - U+0076d
429          U+01800 - U+01805
430          U+01d00 - U+01d77
431          U+01d9b - U+01dbf
432          U+0200b - U+0200f
433          U+030fc - U+030fe
434          U+03260 - U+0327f
435          U+0fb46 - U+0fbb1
436          U+10450 - U+1049d
438    12. The -o option (show only the matching part of a line) for pcregrep was not
439        compatible with GNU grep in that, if there was more than one match in a
440        line, it showed only the first of them. It now behaves in the same way as
441        GNU grep.
443    13. If the -o and -v options were combined for pcregrep, it printed a blank
444        line for every non-matching line. GNU grep prints nothing, and pcregrep now
445        does the same. The return code can be used to tell if there were any
446        non-matching lines.
448    14. Added --file-offsets and --line-offsets to pcregrep.
450    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
451        infinitely looping recursion. The bug was that positive lookaheads were not
452        being skipped when checking for a possible empty match (negative lookaheads
453        and both kinds of lookbehind were skipped).
455    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
456        inclusion of <windows.h> to before rather than after the definition of
457        INVALID_FILE_ATTRIBUTES (patch from David Byron).
459    17. Specifying a possessive quantifier with a specific limit for a Unicode
460        character property caused pcre_compile() to compile bad code, which led at
461        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
462        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
463        caused the error; without that there was no problem.
465    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
467    19. Added --enable-pcretest-libreadline.
469    20. In pcrecpp.cc, the variable 'count' was incremented twice in
470        RE::GlobalReplace(). As a result, the number of replacements returned was
471        double what it should be. I removed one of the increments, but Craig sent a
472        later patch that removed the other one (the right fix) and added unit tests
473        that check the return values (which was not done before).
475    21. Several CMake things:
477        (1) Arranged that, when cmake is used on Unix, the libraries end up with
478            the names libpcre and libpcreposix, not just pcre and pcreposix.
480        (2) The above change means that pcretest and pcregrep are now correctly
481            linked with the newly-built libraries, not previously installed ones.
485    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
486        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
487        UTF-8 newline character). The key issue is that the pattern starts .*;
488        this means that the match must be either at the beginning, or after a
489        newline. The bug was in the code for advancing after a failed match and
490        checking that the new position followed a newline. It was not taking
491        account of UTF-8 characters correctly.
493    23. PCRE was behaving differently from Perl in the way it recognized POSIX
494        character classes. PCRE was not treating the sequence [:...:] as a
495        character class unless the ... were all letters. Perl, however, seems to
496        allow any characters between [: and :], though of course it rejects as
497        unknown any "names" that contain non-letters, because all the known class
498        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
499        for example, whereas PCRE did not - it did not recognize a POSIX character
500        class. This seemed a bit dangerous, so the code has been changed to be
501        closer to Perl. The behaviour is not identical to Perl, because PCRE will
502        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
503        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
504        Perl does, and where it didn't before.
506    24. Rewrite so as to remove the single use of %n from pcregrep because in some
507        Windows environments %n is disabled by default.
510    Version 7.4 21-Sep-07
511    ---------------------
513    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
514        means that a class such as [\s] counted as "explicit reference to CR or
515        LF". That isn't really right - the whole point of the change was to try to
516        help when there was an actual mention of one of the two characters. So now
517        the change happens only if \r or \n (or a literal CR or LF) character is
518        encountered.
520    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
521        of both had grown to the point where there were only 3 bits left.
522        Fortunately, there was spare space in the data structure, and so I have
523        moved the internal flags into a new 16-bit field to free up more option
524        bits.
526    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
527        but did not set the internal JCHANGED flag - either of these is enough to
528        control the way the "get" function works - but the PCRE_INFO_JCHANGED
529        facility is supposed to tell if (?J) was ever used, so now (?J) at the
530        start sets both bits.
532    4.  Added options (at build time, compile time, exec time) to change \R from
533        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
535    5.  doc/pcresyntax.html was missing from the distribution.
537    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
538        compatibility, even though it is no longer used.
540    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
541        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
542        windows.h file is present (where different names are used). [This was
543        reversed later after testing - see 16 below.]
545    8.  Changed all #include <config.h> to #include "config.h". There were also
546        some further <pcre.h> cases that I changed to "pcre.h".
548    9.  When pcregrep was used with the --colour option, it missed the line ending
549        sequence off the lines that it output.
551    10. It was pointed out to me that arrays of string pointers cause lots of
552        relocations when a shared library is dynamically loaded. A technique of
553        using a single long string with a table of offsets can drastically reduce
554        these. I have refactored PCRE in four places to do this. The result is
555        dramatic:
557          Originally:                          290
558          After changing UCP table:            187
559          After changing error message table:   43
560          After changing table of "verbs"       36
561          After changing table of Posix names   22
563        Thanks to the folks working on Gregex for glib for this insight.
565    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
566        unicode-properties was also set.
568    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
570    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
571        checked only for CRLF.
573    14. Added casts to pcretest.c to avoid compiler warnings.
575    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
577    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
578        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
579        entirely. This removes changes made in 7 above.
581    17. The CMake files have been updated, and there is now more information about
582        building with CMake in the NON-UNIX-USE document.
585    Version 7.3 28-Aug-07
586    ---------------------
588     1. In the rejigging of the build system that eventually resulted in 7.1, the
589        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
590        brackets there is not right, since it causes compilers to look for an
591        installed pcre.h, not the version that is in the source that is being
592        compiled (which of course may be different). I have changed it back to:
594          #include "pcre.h"
596        I have a vague recollection that the change was concerned with compiling in
597        different directories, but in the new build system, that is taken care of
598        by the VPATH setting the Makefile.
600     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
601        when the subject happened to end in the byte 0x85 (e.g. if the last
602        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
603        characters but of course it shouldn't be taken as a newline when it is part
604        of another character. The bug was that, for an unlimited repeat of . in
605        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
606        characters when looking for a newline.
608     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
610     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
611        in debug output.
613     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
614        long printing in the pcrecpp unittest when running under MinGW.
616     6. ESC_K was left out of the EBCDIC table.
618     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
619        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
620        limit also applies to "virtual nesting" when a pattern is recursive, and in
621        this case 1000 isn't so big. I have been able to remove this limit at the
622        expense of backing off one optimization in certain circumstances. Normally,
623        when pcre_exec() would call its internal match() function recursively and
624        immediately return the result unconditionally, it uses a "tail recursion"
625        feature to save stack. However, when a subpattern that can match an empty
626        string has an unlimited repetition quantifier, it no longer makes this
627        optimization. That gives it a stack frame in which to save the data for
628        checking that an empty string has been matched. Previously this was taken
629        from the 1000-entry workspace that had been reserved. So now there is no
630        explicit limit, but more stack is used.
632     8. Applied Daniel's patches to solve problems with the import/export magic
633        syntax that is required for Windows, and which was going wrong for the
634        pcreposix and pcrecpp parts of the library. These were overlooked when this
635        problem was solved for the main library.
637     9. There were some crude static tests to avoid integer overflow when computing
638        the size of patterns that contain repeated groups with explicit upper
639        limits. As the maximum quantifier is 65535, the maximum group length was
640        set at 30,000 so that the product of these two numbers did not overflow a
641        32-bit integer. However, it turns out that people want to use groups that
642        are longer than 30,000 bytes (though not repeat them that many times).
643        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
644        made it possible to implement the integer overflow checks in a much more
645        dynamic way, which I have now done. The artificial limitation on group
646        length has been removed - we now have only the limit on the total length of
647        the compiled pattern, which depends on the LINK_SIZE setting.
649    10. Fixed a bug in the documentation for get/copy named substring when
650        duplicate names are permitted. If none of the named substrings are set, the
651        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
652        empty string.
654    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
655        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
656        because the ] is interpreted as the first data character and the
657        terminating ] is not found. PCRE has been made compatible with Perl in this
658        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
659        cause memory overwriting.
661    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
662        string has been matched (to stop an infinite loop). It was not recognizing
663        a conditional subpattern that could match an empty string if that
664        subpattern was within another subpattern. For example, it looped when
665        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
666        condition was not nested. This bug has been fixed.
668    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
669        past the start of the subject in the presence of bytes with the top bit
670        set, for example "\x8aBCD".
672    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
673        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
675    14. Optimized (?!) to (*FAIL).
677    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
678        This restricts code points to be within the range 0 to 0x10FFFF, excluding
679        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
680        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
681        does: it's just the validity check that is more restrictive.
683    16. Inserted checks for integer overflows during escape sequence (backslash)
684        processing, and also fixed erroneous offset values for syntax errors during
685        backslash processing.
687    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
688        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
690    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
691        caused an overrun.
693    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
694        something other than just ASCII characters) inside a group that had an
695        unlimited repeat caused a loop at compile time (while checking to see
696        whether the group could match an empty string).
698    20. Debugging a pattern containing \p or \P could cause a crash. For example,
699        [\P{Any}] did so. (Error in the code for printing property names.)
701    21. An orphan \E inside a character class could cause a crash.
703    22. A repeated capturing bracket such as (A)? could cause a wild memory
704        reference during compilation.
706    23. There are several functions in pcre_compile() that scan along a compiled
707        expression for various reasons (e.g. to see if it's fixed length for look
708        behind). There were bugs in these functions when a repeated \p or \P was
709        present in the pattern. These operators have additional parameters compared
710        with \d, etc, and these were not being taken into account when moving along
711        the compiled data. Specifically:
713        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
714            length.
716        (b) An item such as \pL+ within a repeated group could cause crashes or
717            loops.
719        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
720            "reference to non-existent subpattern" error.
722        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
724    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
725        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
727    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
729    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
730        character were causing crashes (broken optimization).
732    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
733        \p or \P) caused a compile-time loop.
735    28. More problems have arisen in unanchored patterns when CRLF is a valid line
736        break. For example, the unstudied pattern [\r\n]A does not match the string
737        "\r\nA" because change 7.0/46 below moves the current point on by two
738        characters after failing to match at the start. However, the pattern \nA
739        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
740        the same is true. There doesn't seem any very clean way out of this, but
741        what I have chosen to do makes the common cases work: PCRE now takes note
742        of whether there can be an explicit match for \r or \n anywhere in the
743        pattern, and if so, 7.0/46 no longer applies. As part of this change,
744        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
745        pattern has explicit CR or LF references.
747    29. Added (*CR) etc for changing newline setting at start of pattern.
750    Version 7.2 19-Jun-07
751    ---------------------
753     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
754        which is apparently normally available under Windows.
756     2. Re-jig the pcregrep tests with different newline settings in an attempt
757        to make them independent of the local environment's newline setting.
759     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
761     4. Some of the "internals" tests were previously cut out when the link size
762        was not 2, because the output contained actual offsets. The recent new
763        "Z" feature of pcretest means that these can be cut out, making the tests
764        usable with all link sizes.
766     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
767        stack recursion. This gives a massive performance boost under BSD, but just
768        a small improvement under Linux. However, it saves one field in the frame
769        in all cases.
771     6. Added more features from the forthcoming Perl 5.10:
773        (a) (?-n) (where n is a string of digits) is a relative subroutine or
774            recursion call. It refers to the nth most recently opened parentheses.
776        (b) (?+n) is also a relative subroutine call; it refers to the nth next
777            to be opened parentheses.
779        (c) Conditions that refer to capturing parentheses can be specified
780            relatively, for example, (?(-2)... or (?(+3)...
782        (d) \K resets the start of the current match so that everything before
783            is not part of it.
785        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
787        (f) \g{name} is another synonym - part of Perl 5.10's unification of
788            reference syntax.
790        (g) (?| introduces a group in which the numbering of parentheses in each
791            alternative starts with the same number.
793        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
795     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
798     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
799        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
800        for detecting groups that can match an empty string.
802     9. A pattern with a very large number of alternatives (more than several
803        hundred) was running out of internal workspace during the pre-compile
804        phase, where pcre_compile() figures out how much memory will be needed. A
805        bit of new cunning has reduced the workspace needed for groups with
806        alternatives. The 1000-alternative test pattern now uses 12 bytes of
807        workspace instead of running out of the 4096 that are available.
809    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
811    11. Applied patch from Google to remove an optimization that didn't quite work.
812        The report of the bug said:
814          pcrecpp::RE("a*").FullMatch("aaa") matches, while
815          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
816          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
818    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
819        it matched the wrong number of bytes.
822    Version 7.1 24-Apr-07
823    ---------------------
825     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
826        that is more "standard", making use of automake and other Autotools. There
827        is some re-arrangement of the files and adjustment of comments consequent
828        on this.
830     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
831        for recursive directory scanning broke on some systems because the files
832        are not scanned in any specific order and on different systems the order
833        was different. A call to "sort" has been inserted into RunGrepTest for the
834        approprate test as a short-term fix. In the longer term there may be an
835        alternative.
837     3. I had an email from Eric Raymond about problems translating some of PCRE's
838        man pages to HTML (despite the fact that I distribute HTML pages, some
839        people do their own conversions for various reasons). The problems
840        concerned the use of low-level troff macros .br and .in. I have therefore
841        removed all such uses from the man pages (some were redundant, some could
842        be replaced by .nf/.fi pairs). The 132html script that I use to generate
843        HTML has been updated to handle .nf/.fi and to complain if it encounters
844        .br or .in.
846     4. Updated comments in configure.ac that get placed in config.h.in and also
847        arranged for config.h to be included in the distribution, with the name
848        config.h.generic, for the benefit of those who have to compile without
849        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
851     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
852        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
853        makevp.bat for the current PCRE, using the additional files
854        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
856     6. A Windows user reported a minor discrepancy with test 2, which turned out
857        to be caused by a trailing space on an input line that had got lost in his
858        copy. The trailing space was an accident, so I've just removed it.
860     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
861        that is needed.
863     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
864        as "const" (a) because they are and (b) because it helps the PHP
865        maintainers who have recently made a script to detect big data structures
866        in the php code that should be moved to the .rodata section. I remembered
867        to update Builducptable as well, so it won't revert if ucptable.h is ever
868        re-created.
870     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
871        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
872        order to be able to cut out the UTF-8 tables in the latter when UTF-8
873        support is not required. This saves 1.5-2K of code, which is important in
874        some applications.
876        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
877        so as not to refer to the tables, even though these functions will never be
878        called when UTF-8 support is disabled. Otherwise there are problems with a
879        shared library.
881    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
883        (a) It was defining its arguments as char * instead of void *.
885        (b) It was assuming that all moves were upwards in memory; this was true
886            a long time ago when I wrote it, but is no longer the case.
888        The emulated memove() is provided for those environments that have neither
889        memmove() nor bcopy(). I didn't think anyone used it these days, but that
890        is clearly not the case, as these two bugs were recently reported.
892    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
893        and Detrail to create the HTML documentation, the .txt form of the man
894        pages, and it removes trailing spaces from listed files. It also creates
895        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
896        case, it wraps all the #defines with #ifndefs. This script should be run
897        before "make dist".
899    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
900        with Unicode property support.
902        (a) For a maximizing quantifier, if the two different cases of the
903            character were of different lengths in their UTF-8 codings (there are
904            some cases like this - I found 11), and the matching function had to
905            back up over a mixture of the two cases, it incorrectly assumed they
906            were both the same length.
908        (b) When PCRE was configured to use the heap rather than the stack for
909            recursion during matching, it was not correctly preserving the data for
910            the other case of a UTF-8 character when checking ahead for a match
911            while processing a minimizing repeat. If the check also involved
912            matching a wide character, but failed, corruption could cause an
913            erroneous result when trying to check for a repeat of the original
914            character.
916    13. Some tidying changes to the testing mechanism:
918        (a) The RunTest script now detects the internal link size and whether there
919            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
920            values substituted by "configure". (The RunGrepTest script already did
921            this for UTF-8.) The configure.ac script no longer substitutes the
922            relevant variables.
924        (b) The debugging options /B and /D in pcretest show the compiled bytecode
925            with length and offset values. This means that the output is different
926            for different internal link sizes. Test 2 is skipped for link sizes
927            other than 2 because of this, bypassing the problem. Unfortunately,
928            there was also a test in test 3 (the locale tests) that used /B and
929            failed for link sizes other than 2. Rather than cut the whole test out,
930            I have added a new /Z option to pcretest that replaces the length and
931            offset values with spaces. This is now used to make test 3 independent
932            of link size. (Test 2 will be tidied up later.)
934    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
935        segmentation fault instead of returning the appropriate error message.
937    15. In multiline mode when the newline sequence was set to "any", the pattern
938        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
939        This doesn't seem right; it now treats the CRLF combination as the line
940        ending, and so does not match in that case. It's only a pattern such as ^$
941        that would hit this one: something like ^ABC$ would have failed after \r
942        and then tried again after \r\n.
944    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
945        in an attempt to make files that differ only in their line terminators
946        compare equal. This works on Linux.
948    17. Under certain error circumstances pcregrep might try to free random memory
949        as it exited. This is now fixed, thanks to valgrind.
951    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
952        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
953        was because its rules for how to advance for /g after matching an empty
954        string at the end of a line did not allow for this case. They now check for
955        it specially.
957    20. pcretest is supposed to handle patterns and data of any length, by
958        extending its buffers when necessary. It was getting this wrong when the
959        buffer for a data line had to be extended.
961    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
962        CRLF as a newline sequence.
964    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
965        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
966        I have nevertheless tidied it up.
968    23. Added some casts to kill warnings from HP-UX ia64 compiler.
970    24. Added a man page for pcre-config.
973    Version 7.0 19-Dec-06
974    ---------------------
976     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
977        moving to gcc 4.1.1.
979     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
980        sys/time.h, which is documented as needed for this function. It doesn't
981        seem to matter on Linux, but it showed up on some releases of OS X.
983     3. It seems that there are systems where bytes whose values are greater than
984        127 match isprint() in the "C" locale. The "C" locale should be the
985        default when a C program starts up. In most systems, only ASCII printing
986        characters match isprint(). This difference caused the output from pcretest
987        to vary, making some of the tests fail. I have changed pcretest so that:
989        (a) When it is outputting text in the compiled version of a pattern, bytes
990            other than 32-126 are always shown as hex escapes.
992        (b) When it is outputting text that is a matched part of a subject string,
993            it does the same, unless a different locale has been set for the match
994            (using the /L modifier). In this case, it uses isprint() to decide.
996     4. Fixed a major bug that caused incorrect computation of the amount of memory
997        required for a compiled pattern when options that changed within the
998        pattern affected the logic of the preliminary scan that determines the
999        length. The relevant options are -x, and -i in UTF-8 mode. The result was
1000        that the computed length was too small. The symptoms of this bug were
1001        either the PCRE error "internal error: code overflow" from pcre_compile(),
1002        or a glibc crash with a message such as "pcretest: free(): invalid next
1003        size (fast)". Examples of patterns that provoked this bug (shown in
1004        pcretest format) are:
1006          /(?-x: )/x
1007          /(?x)(?-x: \s*#\s*)/
1008          /((?i)[\x{c0}])/8
1009          /(?i:[\x{c0}])/8
1011        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1012        is now done differently.
1014     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1015        wrapper classes; (b) implement a new function in the C++ scanner that is
1016        more efficient than the old way of doing things because it avoids levels of
1017        recursion in the regex matching; (c) add a paragraph to the documentation
1018        for the FullMatch() function.
1020     6. The escape sequence \n was being treated as whatever was defined as
1021        "newline". Not only was this contrary to the documentation, which states
1022        that \n is character 10 (hex 0A), but it also went horribly wrong when
1023        "newline" was defined as CRLF. This has been fixed.
1025     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1026        was being set to -1 for the "end of line" case (supposedly a value that no
1027        character can have). Though this value is never used (the check for end of
1028        line is "zero bytes in current character"), it caused compiler complaints.
1029        I've changed it to 0xffffffff.
1031     8. In pcre_version.c, the version string was being built by a sequence of
1032        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1033        string (as it is for production releases) called a macro with an empty
1034        argument. The C standard says the result of this is undefined. The gcc
1035        compiler treats it as an empty string (which was what was wanted) but it is
1036        reported that Visual C gives an error. The source has been hacked around to
1037        avoid this problem.
1039     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1040        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1041        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1042        of them did).
1044    10. Originally, pcretest opened its input and output without "b"; then I was
1045        told that "b" was needed in some environments, so it was added for release
1046        5.0 to both the input and output. (It makes no difference on Unix-like
1047        systems.) Later I was told that it is wrong for the input on Windows. I've
1048        now abstracted the modes into two macros, to make it easier to fiddle with
1049        them, and removed "b" from the input mode under Windows.
1051    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1053    12. Added -help and --help to pcretest as an official way of being reminded
1054        of the options.
1056    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1057        and pcrecpp.cc because they annoy compilers at high warning levels.
1059    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1061    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1062        scripts are not C programs :-) and which was not noticed because it works
1063        on Linux.
1065    16. pcretest is supposed to handle any length of pattern and data line (as one
1066        line or as a continued sequence of lines) by extending its input buffer if
1067        necessary. This feature was broken for very long pattern lines, leading to
1068        a string of junk being passed to pcre_compile() if the pattern was longer
1069        than about 50K.
1071    17. I have done a major re-factoring of the way pcre_compile() computes the
1072        amount of memory needed for a compiled pattern. Previously, there was code
1073        that made a preliminary scan of the pattern in order to do this. That was
1074        OK when PCRE was new, but as the facilities have expanded, it has become
1075        harder and harder to keep it in step with the real compile phase, and there
1076        have been a number of bugs (see for example, 4 above). I have now found a
1077        cunning way of running the real compile function in a "fake" mode that
1078        enables it to compute how much memory it would need, while actually only
1079        ever using a few hundred bytes of working memory and without too many
1080        tests of the mode. This should make future maintenance and development
1081        easier. A side effect of this work is that the limit of 200 on the nesting
1082        depth of parentheses has been removed (though this was never a serious
1083        limitation, I suspect). However, there is a downside: pcre_compile() now
1084        runs more slowly than before (30% or more, depending on the pattern). I
1085        hope this isn't a big issue. There is no effect on runtime performance.
1087    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1088        newline (only possible for the last line of a file) and it was a
1089        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1091    19. Added additional timing features to pcretest. (1) The -tm option now times
1092        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1093        separate command line item, by a number that specifies the number of
1094        repeats to use when timing. The default is 50000; this gives better
1095        precision, but takes uncomfortably long for very large patterns.
1097    20. Extended pcre_study() to be more clever in cases where a branch of a
1098        subpattern has no definite first character. For example, (a*|b*)[cd] would
1099        previously give no result from pcre_study(). Now it recognizes that the
1100        first character must be a, b, c, or d.
1102    21. There was an incorrect error "recursive call could loop indefinitely" if
1103        a subpattern (or the entire pattern) that was being tested for matching an
1104        empty string contained only one non-empty item after a nested subpattern.
1105        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1106        incorrectly, because the \d was being skipped in the check.
1108    22. The pcretest program now has a new pattern option /B and a command line
1109        option -b, which is equivalent to adding /B to every pattern. This causes
1110        it to show the compiled bytecode, without the additional information that
1111        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1112        is the same as /B/I).
1114    23. A new optimization is now able automatically to treat some sequences such
1115        as a*b as a*+b. More specifically, if something simple (such as a character
1116        or a simple class like \d) has an unlimited quantifier, and is followed by
1117        something that cannot possibly match the quantified thing, the quantifier
1118        is automatically "possessified".
1120    24. A recursive reference to a subpattern whose number was greater than 39
1121        went wrong under certain circumstances in UTF-8 mode. This bug could also
1122        have affected the operation of pcre_study().
1124    25. Realized that a little bit of performance could be had by replacing
1125        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1127    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1129    27. Possessive quantifiers such as a++ were previously implemented by turning
1130        them into atomic groups such as ($>a+). Now they have their own opcodes,
1131        which improves performance. This includes the automatically created ones
1132        from 23 above.
1134    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1135        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1136        the first matched character to be a colon. This applied both to named and
1137        numbered groups.
1139    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1141    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1142        building PCRE on Windows easier, so I have included it in the distribution.
1144    31. There is now a check in pcretest against a ridiculously large number being
1145        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1146        loop, the loop is abandoned.
1148    32. Forward references to subpatterns in conditions such as (?(2)...) where
1149        subpattern 2 is defined later cause pcre_compile() to search forwards in
1150        the pattern for the relevant set of parentheses. This search went wrong
1151        when there were unescaped parentheses in a character class, parentheses
1152        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1154    33. "Subroutine" calls and backreferences were previously restricted to
1155        referencing subpatterns earlier in the regex. This restriction has now
1156        been removed.
1158    34. Added a number of extra features that are going to be in Perl 5.10. On the
1159        whole, these are just syntactic alternatives for features that PCRE had
1160        previously implemented using the Python syntax or my own invention. The
1161        other formats are all retained for compatibility.
1163        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1164            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1165            also .NET compatible.
1167        (b) A recursion or subroutine call to a named group can now be defined as
1168            (?&name) as well as (?P>name).
1170        (c) A backreference to a named group can now be defined as \k<name> or
1171            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1172            5.10, are also .NET compatible.
1174        (d) A conditional reference to a named group can now use the syntax
1175            (?(<name>) or (?('name') as well as (?(name).
1177        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1178            groups (named and numbered) that are never evaluated inline, but can be
1179            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1180            is always false. There may be only one alternative in such a group.
1182        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1183            as the simple (?(R). The condition is true only if the most recent
1184            recursion is that of the given number or name. It does not search out
1185            through the entire recursion stack.
1187        (g) The escape \gN or \g{N} has been added, where N is a positive or
1188            negative number, specifying an absolute or relative reference.
1190    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1191        some "unreachable code" warnings.
1193    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1194        things, this adds five new scripts.
1196    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1197        There were also incompatibilities regarding the handling of \Q..\E inside
1198        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1199        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1201    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1202        matches an empty string, and forcibly breaks the loop. There were bugs in
1203        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1204        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1205        separate and independent bugs (that affected different cases) have been
1206        fixed.
1208    39. Refactored the code to abolish the use of different opcodes for small
1209        capturing bracket numbers. This is a tidy that I avoided doing when I
1210        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1211        The new approach is not only tidier, it makes it possible to reduce the
1212        memory needed to fix the previous bug (38).
1214    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1215        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1216        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1217        mode.
1219    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1220        report.
1222    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1223        copy construction and assignment in the C++ wrapper.
1225    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1226        couple of bugs that could have given wrong results in the "--newline=crlf"
1227        case.
1229    44. Added a number of casts and did some reorganization of signed/unsigned int
1230        variables following suggestions from Dair Grant. Also renamed the variable
1231        "this" as "item" because it is a C++ keyword.
1233    45. Arranged for dftables to add
1235          #include "pcre_internal.h"
1237        to pcre_chartables.c because without it, gcc 4.x may remove the array
1238        definition from the final binary if PCRE is built into a static library and
1239        dead code stripping is activated.
1241    46. For an unanchored pattern, if a match attempt fails at the start of a
1242        newline sequence, and the newline setting is CRLF or ANY, and the next two
1243        characters are CRLF, advance by two characters instead of one.
1246    Version 6.7 04-Jul-06
1247    ---------------------
1249     1. In order to handle tests when input lines are enormously long, pcretest has
1250        been re-factored so that it automatically extends its buffers when
1251        necessary. The code is crude, but this _is_ just a test program. The
1252        default size has been increased from 32K to 50K.
1254     2. The code in pcre_study() was using the value of the re argument before
1255        testing it for NULL. (Of course, in any sensible call of the function, it
1256        won't be NULL.)
1258     3. The memmove() emulation function in pcre_internal.h, which is used on
1259        systems that lack both memmove() and bcopy() - that is, hardly ever -
1260        was missing a "static" storage class specifier.
1262     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1263        containing an extended class (one that cannot be represented by a bitmap
1264        because it contains high-valued characters or Unicode property items, e.g.
1265        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1266        pattern, but PCRE should not loop if you do not (it no longer does).
1267        [Detail: two cases were found: (a) a repeated subpattern containing an
1268        extended class; (b) a recursive reference to a subpattern that followed a
1269        previous extended class. It wasn't skipping over the extended class
1270        correctly when UTF-8 mode was not set.]
1272     5. A negated single-character class was not being recognized as fixed-length
1273        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1274        compile error "lookbehind assertion is not fixed length".
1276     6. The RunPerlTest auxiliary script was showing an unexpected difference
1277        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1278        write a Perl script that can interpret lines of an input file either as
1279        byte characters or as UTF-8, which is what "perltest" was being required to
1280        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1281        can't do is switch easily at run time between having the "use utf8;" pragma
1282        or not. In the end, I fudged it by using the RunPerlTest script to insert
1283        "use utf8;" explicitly for the UTF-8 tests.
1285     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1286        the end of the subject string, contrary to the documentation and to what
1287        Perl does. This was true of both matching functions. Now it matches only at
1288        the start of the subject and immediately after *internal* newlines.
1290     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1291        a pointer to an int instead of a pointer to an unsigned long int. This
1292        caused problems on 64-bit systems.
1294     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1295        instance of the 'standard' template library not being so standard".
1297    10. There was no check on the number of named subpatterns nor the maximum
1298        length of a subpattern name. The product of these values is used to compute
1299        the size of the memory block for a compiled pattern. By supplying a very
1300        long subpattern name and a large number of named subpatterns, the size
1301        computation could be caused to overflow. This is now prevented by limiting
1302        the length of names to 32 characters, and the number of named subpatterns
1303        to 10,000.
1305    11. Subpatterns that are repeated with specific counts have to be replicated in
1306        the compiled pattern. The size of memory for this was computed from the
1307        length of the subpattern and the repeat count. The latter is limited to
1308        65535, but there was no limit on the former, meaning that integer overflow
1309        could in principle occur. The compiled length of a repeated subpattern is
1310        now limited to 30,000 bytes in order to prevent this.
1312    12. Added the optional facility to have named substrings with the same name.
1314    13. Added the ability to use a named substring as a condition, using the
1315        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1316        are numbers (not recommended). Forward references are permitted.
1318    14. Added forward references in named backreferences (if you see what I mean).
1320    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1321        pattern could run off the end of the subject. For example, the pattern
1322        "(?s)(.{1,5})"8 did this with the subject "ab".
1324    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1325        PCRE_CASELESS was set when matching characters that were quantified with ?
1326        or *.
1328    17. A character class other than a single negated character that had a minimum
1329        but no maximum quantifier - for example [ab]{6,} - was not handled
1330        correctly by pce_dfa_exec(). It would match only one character.
1332    18. A valid (though odd) pattern that looked like a POSIX character
1333        class but used an invalid character after [ (for example [[,abc,]]) caused
1334        pcre_compile() to give the error "Failed: internal error: code overflow" or
1335        in some cases to crash with a glibc free() error. This could even happen if
1336        the pattern terminated after [[ but there just happened to be a sequence of
1337        letters, a binary zero, and a closing ] in the memory that followed.
1339    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1340        over the years. Originally (before any Unicode support), just the bottom 8
1341        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1342        output from "man perlunicode" includes this:
1344          The regular expression compiler produces polymorphic opcodes.  That
1345          is, the pattern adapts to the data and automatically switches to
1346          the Unicode character scheme when presented with Unicode data--or
1347          instead uses a traditional byte scheme when presented with byte
1348          data.
1350        Sadly, a wide octal escape does not cause a switch, and in a string with
1351        no other multibyte characters, these octal escapes are treated as before.
1352        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1353        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1354        Unicode string.
1356        I have not perpetrated such confusion in PCRE. Up till now, it took just
1357        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1358        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1359        translate to the appropriate multibyte character.
1361    29. Applied some refactoring to reduce the number of warnings from Microsoft
1362        and Borland compilers. This has included removing the fudge introduced
1363        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1364        a warning about an unused variable.
1366    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1367        characters since release 4.0, because Perl (from release 5.004) does not.
1368        [Or at least, is documented not to: some releases seem to be in conflict
1369        with the documentation.] However, when a pattern was studied with
1370        pcre_study() and all its branches started with \s, PCRE still included VT
1371        as a possible starting character. Of course, this did no harm; it just
1372        caused an unnecessary match attempt.
1374    22. Removed a now-redundant internal flag bit that recorded the fact that case
1375        dependency changed within the pattern. This was once needed for "required
1376        byte" processing, but is no longer used. This recovers a now-scarce options
1377        bit. Also moved the least significant internal flag bit to the most-
1378        significant bit of the word, which was not previously used (hangover from
1379        the days when it was an int rather than a uint) to free up another bit for
1380        the future.
1382    23. Added support for CRLF line endings as well as CR and LF. As well as the
1383        default being selectable at build time, it can now be changed at runtime
1384        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1385        specify that it is scanning data with non-default line endings.
1387    24. Changed the definition of CXXLINK to make it agree with the definition of
1388        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1390    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1391        recursions. This makes a big different to stack usage for some patterns.
1393    26. If a subpattern containing a named recursion or subroutine reference such
1394        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1395        the space required for the compiled pattern went wrong and gave too small a
1396        value. Depending on the environment, this could lead to "Failed: internal
1397        error: code overflow at offset 49" or "glibc detected double free or
1398        corruption" errors.
1400    27. Applied patches from Google (a) to support the new newline modes and (b) to
1401        advance over multibyte UTF-8 characters in GlobalReplace.
1403    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1404        difference for some implementation of PCRE in some Windows version.
1406    29. Added some extra testing facilities to pcretest:
1408        \q<number>   in a data line sets the "match limit" value
1409        \Q<number>   in a data line sets the "match recursion limt" value
1410        -S <number>  sets the stack size, where <number> is in megabytes
1412        The -S option isn't available for Windows.
1415    Version 6.6 06-Feb-06
1416    ---------------------
1418     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1419        in pcreposix.h. I have copied the definition from pcre.h.
1421     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1422        because pcre.h is no longer a built file.
1424     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1425        not normally included in the compiled code.
1428    Version 6.5 01-Feb-06
1429    ---------------------
1431     1. When using the partial match feature with pcre_dfa_exec(), it was not
1432        anchoring the second and subsequent partial matches at the new starting
1433        point. This could lead to incorrect results. For example, with the pattern
1434        /1234/, partially matching against "123" and then "a4" gave a match.
1436     2. Changes to pcregrep:
1438        (a) All non-match returns from pcre_exec() were being treated as failures
1439            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1440            error message is output. Some extra information is given for the
1441            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1442            probably the only errors that are likely to be caused by users (by
1443            specifying a regex that has nested indefinite repeats, for instance).
1444            If there are more than 20 of these errors, pcregrep is abandoned.
1446        (b) A binary zero was treated as data while matching, but terminated the
1447            output line if it was written out. This has been fixed: binary zeroes
1448            are now no different to any other data bytes.
1450        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1451            used to set a locale for matching. The --locale=xxxx long option has
1452            been added (no short equivalent) to specify a locale explicitly on the
1453            pcregrep command, overriding the environment variables.
1455        (d) When -B was used with -n, some line numbers in the output were one less
1456            than they should have been.
1458        (e) Added the -o (--only-matching) option.
1460        (f) If -A or -C was used with -c (count only), some lines of context were
1461            accidentally printed for the final match.
1463        (g) Added the -H (--with-filename) option.
1465        (h) The combination of options -rh failed to suppress file names for files
1466            that were found from directory arguments.
1468        (i) Added the -D (--devices) and -d (--directories) options.
1470        (j) Added the -F (--fixed-strings) option.
1472        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1474        (l) Added the --colo(u)r option.
1476        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1477            is not present by default.
1479     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1480        items such as (?R) or (?1), when the recursion could match a number of
1481        alternatives. If it matched one of the alternatives, but subsequently,
1482        outside the recursion, there was a failure, the code tried to back up into
1483        the recursion. However, because of the way PCRE is implemented, this is not
1484        possible, and the result was an incorrect result from the match.
1486        In order to prevent this happening, the specification of recursion has
1487        been changed so that all such subpatterns are automatically treated as
1488        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1490     4. I had overlooked the fact that, in some locales, there are characters for
1491        which isalpha() is true but neither isupper() nor islower() are true. In
1492        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1493        and ordfeminine) are like this. This affected the treatment of \w and \W
1494        when they appeared in character classes, but not when they appeared outside
1495        a character class. The bit map for "word" characters is now created
1496        separately from the results of isalnum() instead of just taking it from the
1497        upper, lower, and digit maps. (Plus the underscore character, of course.)
1499     5. The above bug also affected the handling of POSIX character classes such as
1500        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1501        permanent tables. Instead, the bit maps for such a class were previously
1502        created as the appropriate unions of the upper, lower, and digit bitmaps.
1503        Now they are created by subtraction from the [[:word:]] class, which has
1504        its own bitmap.
1506     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1507        It is created by subtracting the vertical space characters (\x09, \x0a,
1508        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1509        subtraction was done in the overall bitmap for a character class, meaning
1510        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1511        be recognized. This bug has been fixed.
1513     7. Patches from the folks at Google:
1515          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1516          real life, but is still worth protecting against".
1518          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1519          regular expressions".
1521          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1522          have it.
1524          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1525          "configure" and the latter not, in order to fix a problem somebody had
1526          with compiling the Arg class on HP-UX.
1528          (e) Improve the error-handling of the C++ wrapper a little bit.
1530          (f) New tests for checking recursion limiting.
1532     8. The pcre_memmove() function, which is used only if the environment does not
1533        have a standard memmove() function (and is therefore rarely compiled),
1534        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1535        returning a result (though PCRE never actually uses the result).
1537     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1538        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1539        returned instead of calling malloc() with an overflowing number that would
1540        most likely cause subsequent chaos.
1542    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1544    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1545        with this option is matched, the nmatch and pmatch options of regexec() are
1546        ignored.
1548    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1549        provided in case anyone wants to the the POSIX interface with UTF-8
1550        strings.
1552    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1553        C++ linking (needed for some HP-UX environments).
1555    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1556        (unused parameter) and in the pcre_printint() function (omitted "default"
1557        switch label when the default is to do nothing).
1559    15. Added some code to make it possible, when PCRE is compiled as a C++
1560        library, to replace subject pointers for pcre_exec() with a smart pointer
1561        class, thus making it possible to process discontinuous strings.
1563    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1564        much the same function. They were added by different people who were trying
1565        to make PCRE easy to compile on non-Unix systems. It has been suggested
1566        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1567        for compiling on Windows systems. I have therefore replaced it with
1568        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1569        defaults to "extern" for C or "extern C" for C++, which works fine on
1570        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1571        SCOPE with something explicit in config.h. In addition:
1573        (a) pcreposix.h still had just "extern" instead of either of these macros;
1574            I have replaced it with PCRE_DATA_SCOPE.
1576        (b) Functions such as _pcre_xclass(), which are internal to the library,
1577            but external in the C sense, all had PCRE_EXPORT in their definitions.
1578            This is apparently wrong for the Windows case, so I have removed it.
1579            (It makes no difference on Unix-like systems.)
1581    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1582        of recursive calls to match(). This is different to MATCH_LIMIT because
1583        that limits the total number of calls to match(), not all of which increase
1584        the depth of recursion. Limiting the recursion depth limits the amount of
1585        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1586        when PCRE is compiled, and changed at run time. A patch from Google adds
1587        this functionality to the C++ interface.
1589    18. Changes to the handling of Unicode character properties:
1591        (a) Updated the table to Unicode 4.1.0.
1593        (b) Recognize characters that are not in the table as "Cn" (undefined).
1595        (c) I revised the way the table is implemented to a much improved format
1596            which includes recognition of ranges. It now supports the ranges that
1597            are defined in UnicodeData.txt, and it also amalgamates other
1598            characters into ranges. This has reduced the number of entries in the
1599            table from around 16,000 to around 3,000, thus reducing its size
1600            considerably. I realized I did not need to use a tree structure after
1601            all - a binary chop search is just as efficient. Having reduced the
1602            number of entries, I extended their size from 6 bytes to 8 bytes to
1603            allow for more data.
1605        (d) Added support for Unicode script names via properties such as \p{Han}.
1607    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1608        matching that character.
1610    20. When matching a repeated Unicode property with a minimum greater than zero,
1611        (for example \pL{2,}), PCRE could look past the end of the subject if it
1612        reached it while seeking the minimum number of characters. This could
1613        happen only if some of the characters were more than one byte long, because
1614        there is a check for at least the minimum number of bytes.
1616    21. Refactored the implementation of \p and \P so as to be more general, to
1617        allow for more different types of property in future. This has changed the
1618        compiled form incompatibly. Anybody with saved compiled patterns that use
1619        \p or \P will have to recompile them.
1621    22. Added "Any" and "L&" to the supported property types.
1623    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1624        but give a compile time error if the value is greater than 0xff.
1626    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1627        accidentally not being installed or uninstalled.
1629    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1630        made were to insert the current release number. This seemed silly, because
1631        it made things harder for people building PCRE on systems that don't run
1632        "configure". I have turned pcre.h into a distributed file, no longer built
1633        by "configure", with the version identification directly included. There is
1634        no longer a pcre.h.in file.
1636        However, this change necessitated a change to the pcre-config script as
1637        well. It is built from pcre-config.in, and one of the substitutions was the
1638        release number. I have updated configure.ac so that ./configure now finds
1639        the release number by grepping pcre.h.
1641    26. Added the ability to run the tests under valgrind.
1644    Version 6.4 05-Sep-05
1645    ---------------------
1647     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1648        "--" to be printed when multiple files were scanned, even when none of the
1649        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1650        consider it to be a bug, and have restored the previous behaviour.
1652     2. A couple of code tidies to get rid of compiler warnings.
1654     3. The pcretest program used to cheat by referring to symbols in the library
1655        whose names begin with _pcre_. These are internal symbols that are not
1656        really supposed to be visible externally, and in some environments it is
1657        possible to suppress them. The cheating is now confined to including
1658        certain files from the library's source, which is a bit cleaner.
1660     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1661        file's purpose clearer.
1663     5. Reorganized pcre_ucp_findchar().
1666    Version 6.3 15-Aug-05
1667    ---------------------
1669     1. The file libpcre.pc.in did not have general read permission in the tarball.
1671     2. There were some problems when building without C++ support:
1673        (a) If C++ support was not built, "make install" and "make test" still
1674            tried to test it.
1676        (b) There were problems when the value of CXX was explicitly set. Some
1677            changes have been made to try to fix these, and ...
1679        (c) --disable-cpp can now be used to explicitly disable C++ support.
1681        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1682            backslash in a target when C++ was disabled. This confuses some
1683            versions of "make", apparently. Using an intermediate variable solves
1684            this. (Same for CPP_LOBJ.)
1686     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1687        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1688        necessary on certain architectures.
1690     4. Added a setting of -export-symbols-regex to the link command to remove
1691        those symbols that are exported in the C sense, but actually are local
1692        within the library, and not documented. Their names all begin with
1693        "_pcre_". This is not a perfect job, because (a) we have to except some
1694        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1695        available (and never for static libraries). I have made a note to try to
1696        find a way round (a) in the future.
1699    Version 6.2 01-Aug-05
1700    ---------------------
1702     1. There was no test for integer overflow of quantifier values. A construction
1703        such as {1111111111111111} would give undefined results. What is worse, if
1704        a minimum quantifier for a parenthesized subpattern overflowed and became
1705        negative, the calculation of the memory size went wrong. This could have
1706        led to memory overwriting.
1708     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1710     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1711        operating environments where this matters.
1713     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1714        PCRE options from within the C++ wrapper.
1716     5. Named capturing subpatterns were not being correctly counted when a pattern
1717        was compiled. This caused two problems: (a) If there were more than 100
1718        such subpatterns, the calculation of the memory needed for the whole
1719        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1720        back references of the form \12, where the number was greater than 9, were
1721        not recognized as back references, even though there were sufficient
1722        previous subpatterns.
1724     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1725        versions of gcc, e.g. 2.95.4.
1728    Version 6.1 21-Jun-05
1729    ---------------------
1731     1. There was one reference to the variable "posix" in pcretest.c that was not
1732        surrounded by "#if !defined NOPOSIX".
1734     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1735        the cross-check on the old pcre_info() function, for the benefit of the
1736        cut-down version of PCRE that is currently imported into Exim.
1738     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1739        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1740        patterns that start (?i) but I don't think that matters. The use of (?i) is
1741        just an example; this all applies to the other options as well.
1743     4. Since libtool seems to echo the compile commands it is issuing, the output
1744        from "make" can be reduced a bit by putting "@" in front of each libtool
1745        compile command.
1747     5. Patch from the folks at Google for configure.in to be a bit more thorough
1748        in checking for a suitable C++ installation before trying to compile the
1749        C++ stuff. This should fix a reported problem when a compiler was present,
1750        but no suitable headers.
1752     6. The man pages all had just "PCRE" as their title. I have changed them to
1753        be the relevant file name. I have also arranged that these names are
1754        retained in the file doc/pcre.txt, which is a concatenation in text format
1755        of all the man pages except the little individual ones for each function.
1757     7. The NON-UNIX-USE file had not been updated for the different set of source
1758        files that come with release 6. I also added a few comments about the C++
1759        wrapper.
1762    Version 6.0 07-Jun-05
1763    ---------------------
1765     1. Some minor internal re-organization to help with my DFA experiments.
1767     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1768        didn't matter for the library itself when fully configured, but did matter
1769        when compiling without UCP support, or within Exim, where the ucp files are
1770        not imported.
1772     3. Refactoring of the library code to split up the various functions into
1773        different source modules. The addition of the new DFA matching code (see
1774        below) to a single monolithic source would have made it really too
1775        unwieldy, quite apart from causing all the code to be include in a
1776        statically linked application, when only some functions are used. This is
1777        relevant even without the DFA addition now that patterns can be compiled in
1778        one application and matched in another.
1780        The downside of splitting up is that there have to be some external
1781        functions and data tables that are used internally in different modules of
1782        the library but which are not part of the API. These have all had their
1783        names changed to start with "_pcre_" so that they are unlikely to clash
1784        with other external names.
1786     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1787        a different (DFA) algorithm. Although it is slower than the original
1788        function, it does have some advantages for certain types of matching
1789        problem.
1791     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1792        including restarting after a partial match.
1794     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1795        defined when compiling for Windows was sent to me. I have put it into the
1796        code, though I have no means of testing or verifying it.
1798     7. Added the pcre_refcount() auxiliary function.
1800     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1801        match before or at the first newline in the subject string. In pcretest,
1802        the /f option on a pattern can be used to set this.
1804     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1805        would behave wrongly. This has been present in PCRE since release 4.0.
1807    10. A number of changes to the pcregrep command:
1809        (a) Refactored how -x works; insert ^(...)$ instead of setting
1810            PCRE_ANCHORED and checking the length, in preparation for adding
1811            something similar for -w.
1813        (b) Added the -w (match as a word) option.
1815        (c) Refactored the way lines are read and buffered so as to have more
1816            than one at a time available.
1818        (d) Implemented a pcregrep test script.
1820        (e) Added the -M (multiline match) option. This allows patterns to match
1821            over several lines of the subject. The buffering ensures that at least
1822            8K, or the rest of the document (whichever is the shorter) is available
1823            for matching (and similarly the previous 8K for lookbehind assertions).
1825        (f) Changed the --help output so that it now says
1827              -w, --word-regex(p)
1829            instead of two lines, one with "regex" and the other with "regexp"
1830            because that confused at least one person since the short forms are the
1831            same. (This required a bit of code, as the output is generated
1832            automatically from a table. It wasn't just a text change.)
1834        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1835            option but starts with a hyphen. Could be a pattern or a path name
1836            starting with a hyphen, for instance.
1838        (h) "-" can be given as a file name to represent stdin.
1840        (i) When file names are being printed, "(standard input)" is used for
1841            the standard input, for compatibility with GNU grep. Previously
1842            "<stdin>" was used.
1844        (j) The option --label=xxx can be used to supply a name to be used for
1845            stdin when file names are being printed. There is no short form.
1847        (k) Re-factored the options decoding logic because we are going to add
1848            two more options that take data. Such options can now be given in four
1849            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1851        (l) Added the -A, -B, and -C options for requesting that lines of context
1852            around matches be printed.
1854        (m) Added the -L option to print the names of files that do not contain
1855            any matching lines, that is, the complement of -l.
1857        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1858            continue to scan other files.
1860        (o) The -s option was incorrectly implemented. For compatibility with other
1861            greps, it now suppresses the error message for a non-existent or non-
1862            accessible file (but not the return code). There is a new option called
1863            -q that suppresses the output of matching lines, which was what -s was
1864            previously doing.
1866        (p) Added --include and --exclude options to specify files for inclusion
1867            and exclusion when recursing.
1869    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1870        Hopefully, it now does.
1872    12. Missing cast in pcre_study().
1874    13. Added an "uninstall" target to the makefile.
1876    14. Replaced "extern" in the function prototypes in Makefile.in with
1877        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1878        world, but is set differently for Windows.
1880    15. Added a second compiling function called pcre_compile2(). The only
1881        difference is that it has an extra argument, which is a pointer to an
1882        integer error code. When there is a compile-time failure, this is set
1883        non-zero, in addition to the error test pointer being set to point to an
1884        error message. The new argument may be NULL if no error number is required
1885        (but then you may as well call pcre_compile(), which is now just a
1886        wrapper). This facility is provided because some applications need a
1887        numeric error indication, but it has also enabled me to tidy up the way
1888        compile-time errors are handled in the POSIX wrapper.
1890    16. Added VPATH=.libs to the makefile; this should help when building with one
1891        prefix path and installing with another. (Or so I'm told by someone who
1892        knows more about this stuff than I do.)
1894    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1895        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1896        match everything, including newlines. This is not POSIX-compatible, but
1897        somebody wanted the feature. From pcretest it can be activated by using
1898        both the P and the s flags.
1900    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1902    19. libpcre.pc was being incorrectly installed as executable.
1904    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1905        it now also looks for '\r' so that it will work unmodified on Windows.
1907    21. Added Google's contributed C++ wrapper to the distribution.
1909    22. Added some untidy missing memory free() calls in pcretest, to keep
1910        Electric Fence happy when testing.
1914    Version 5.0 13-Sep-04
1915    ---------------------
1917     1. Internal change: literal characters are no longer packed up into items
1918        containing multiple characters in a single byte-string. Each character
1919        is now matched using a separate opcode. However, there may be more than one
1920        byte in the character in UTF-8 mode.
1922     2. The pcre_callout_block structure has two new fields: pattern_position and
1923        next_item_length. These contain the offset in the pattern to the next match
1924        item, and its length, respectively.
1926     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1927        insertion of callouts before each pattern item. Added the /C option to
1928        pcretest to make use of this.
1930     4. On the advice of a Windows user, the lines
1932          #if defined(_WIN32) || defined(WIN32)
1933          _setmode( _fileno( stdout ), 0x8000 );
1934          #endif  /* defined(_WIN32) || defined(WIN32) */
1936        have been added to the source of pcretest. This apparently does useful
1937        magic in relation to line terminators.
1939     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1940        for the benefit of those environments where the "b" makes a difference.
1942     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1943        to know about it. I have put a hack into configure.in that adds in code
1944        to set GCC=yes if CC=icc. This seems to end up at a point in the
1945        generated configure script that is early enough to affect the setting of
1946        compiler options, which is what is needed, but I have no means of testing
1947        whether it really works. (The user who reported this had patched the
1948        generated configure script, which of course I cannot do.)
1950        LATER: After change 22 below (new libtool files), the configure script
1951        seems to know about icc (and also ecc). Therefore, I have commented out
1952        this hack in configure.in.
1954     7. Added support for pkg-config (2 patches were sent in).
1956     8. Negated POSIX character classes that used a combination of internal tables
1957        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1958        [[:^ascii]]. Typically, they would match almost any characters. The other
1959        POSIX classes were not broken in this way.
1961     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1962        to find the match, as PCRE was deluded into thinking that the match had to
1963        start at the start point or following a newline. The same bug applied to
1964        patterns with negative forward assertions or any backward assertions
1965        preceding ".*" at the start, unless the pattern required a fixed first
1966        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1968    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1969        starting at the last subject character, bytes beyond the end of the subject
1970        string were read.
1972    11. Renamed the variable "class" as "classbits" to make life easier for C++
1973        users. (Previously there was a macro definition, but it apparently wasn't
1974        enough.)
1976    12. Added the new field "tables" to the extra data so that tables can be passed
1977        in at exec time, or the internal tables can be re-selected. This allows
1978        a compiled regex to be saved and re-used at a later time by a different
1979        program that might have everything at different addresses.
1981    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1982        -R library as well as a -L library.
1984    14. The debugging options of pcretest (-d on the command line or D on a
1985        pattern) showed incorrect output for anything following an extended class
1986        that contained multibyte characters and which was followed by a quantifier.
1988    15. Added optional support for general category Unicode character properties
1989        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1990        support. It adds about 90K to the size of the library. The meanings of the
1991        inbuilt class escapes such as \d and \s have NOT been changed.
1993    16. Updated pcredemo.c to include calls to free() to release the memory for the
1994        compiled pattern.
1996    17. The generated file chartables.c was being created in the source directory
1997        instead of in the building directory. This caused the build to fail if the
1998        source directory was different from the building directory, and was
1999        read-only.
2001    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2002        file. No doubt somebody will tell me if they don't make sense... Also added
2003        Dan Mooney's comments about building on OpenVMS.
2005    19. Added support for partial matching via the PCRE_PARTIAL option for
2006        pcre_exec() and the \P data escape in pcretest.
2008    20. Extended pcretest with 3 new pattern features:
2010        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
2011              write the compiled pattern to the file whose name is "rest-of-line".
2012              This is a straight binary dump of the data, with the saved pointer to
2013              the character tables forced to be NULL. The study data, if any, is
2014              written too. After writing, pcretest reads a new pattern.
2016        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2017              compiled pattern from the given file. There must not be any
2018              occurrences of "<" in the file name (pretty unlikely); if there are,
2019              pcretest will instead treat the initial "<" as a pattern delimiter.
2020              After reading in the pattern, pcretest goes on to read data lines as
2021              usual.
2023        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2024              and 16-bit fields in a compiled pattern, to simulate a pattern that
2025              was compiled on a host of opposite endianness.
2027    21. The pcre-exec() function can now cope with patterns that were compiled on
2028        hosts of opposite endianness, with this restriction:
2030          As for any compiled expression that is saved and used later, the tables
2031          pointer field cannot be preserved; the extra_data field in the arguments
2032          to pcre_exec() should be used to pass in a tables address if a value
2033          other than the default internal tables were used at compile time.
2035    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2036        now diagnosed as an error. Previously, most of the time, a negative number
2037        would have been treated as zero, but if in addition "ovector" was passed as
2038        NULL, a crash could occur.
2040    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2041        new versions from the libtool 1.5 distribution (the last one is a copy of
2042        a file called libtool.m4). This seems to have fixed the need to patch
2043        "configure" to support Darwin 1.3 (which I used to do). However, I still
2044        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2045        workstation).
2047    24. Changed the PCRE licence to be the more standard "BSD" licence.
2050    Version 4.5 01-Dec-03
2051    ---------------------
2053     1. There has been some re-arrangement of the code for the match() function so
2054        that it can be compiled in a version that does not call itself recursively.
2055        Instead, it keeps those local variables that need separate instances for
2056        each "recursion" in a frame on the heap, and gets/frees frames whenever it
2057        needs to "recurse". Keeping track of where control must go is done by means
2058        of setjmp/longjmp. The whole thing is implemented by a set of macros that
2059        hide most of the details from the main code, and operates only if
2060        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2061        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2062        operating.
2064        To make it easier for callers to provide specially tailored get/free
2065        functions for this usage, two new functions, pcre_stack_malloc, and
2066        pcre_stack_free, are used. They are always called in strict stacking order,
2067        and the size of block requested is always the same.
2069        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2070        PCRE has been compiled to use the stack or the heap for recursion. The
2071        -C option of pcretest uses this to show which version is compiled.
2073        A new data escape \S, is added to pcretest; it causes the amounts of store
2074        obtained and freed by both kinds of malloc/free at match time to be added
2075        to the output.
2077     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2078        what's available on my current Linux desktop machine.
2080     3. When matching a UTF-8 string, the test for a valid string at the start has
2081        been extended. If start_offset is not zero, PCRE now checks that it points
2082        to a byte that is the start of a UTF-8 character. If not, it returns
2083        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2084        this is necessary because there may be backward assertions in the pattern.
2085        When matching the same subject several times, it may save resources to use
2086        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2088     4. The code for checking the validity of UTF-8 strings has been tightened so
2089        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2090        containing "overlong sequences".
2092     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2093        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2094        should have been "&", but it just so happened that all the cases this let
2095        through by mistake were picked up later in the function.
2097     6. I had used a variable called "isblank" - this is a C99 function, causing
2098        some compilers to warn. To avoid this, I renamed it (as "blankclass").
2100     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2101        prompting; (b) run "./pcretest /dev/null" at the start of the test script
2102        so the version is shown; (c) stop "make test" echoing "./RunTest".
2104     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2106     9. The prototype for memmove() for systems that don't have it was using
2107        size_t, but the inclusion of the header that defines size_t was later. I've
2108        moved the #includes for the C headers earlier to avoid this.
2110    10. Added some adjustments to the code to make it easier to compiler on certain
2111        special systems:
2113          (a) Some "const" qualifiers were missing.
2114          (b) Added the macro EXPORT before all exported functions; by default this
2115              is defined to be empty.
2116          (c) Changed the dftables auxiliary program (that builds chartables.c) so
2117              that it reads its output file name as an argument instead of writing
2118              to the standard output and assuming this can be redirected.
2120    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2121        class containing characters with values greater than 255, PCRE compilation
2122        went into a loop.
2124    12. A recursive reference to a subpattern that was within another subpattern
2125        that had a minimum quantifier of zero caused PCRE to crash. For example,
2126        (x(y(?2))z)? provoked this bug with a subject that got as far as the
2127        recursion. If the recursively-called subpattern itself had a zero repeat,
2128        that was OK.
2130    13. In pcretest, the buffer for reading a data line was set at 30K, but the
2131        buffer into which it was copied (for escape processing) was still set at
2132        1024, so long lines caused crashes.
2134    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2135        "internal error: code overflow...". This applied to any character class
2136        that was followed by a possessive quantifier.
2138    15. Modified the Makefile to add libpcre.la as a prerequisite for
2139        libpcreposix.la because I was told this is needed for a parallel build to
2140        work.
2142    16. If a pattern that contained .* following optional items at the start was
2143        studied, the wrong optimizing data was generated, leading to matching
2144        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2145        matching string must start with a or b or c. The correct conclusion for
2146        this pattern is that a match can start with any character.
2149    Version 4.4 13-Aug-03
2150    ---------------------
2152     1. In UTF-8 mode, a character class containing characters with values between
2153        127 and 255 was not handled correctly if the compiled pattern was studied.
2154        In fixing this, I have also improved the studying algorithm for such
2155        classes (slightly).
2157     2. Three internal functions had redundant arguments passed to them. Removal
2158        might give a very teeny performance improvement.
2160     3. Documentation bug: the value of the capture_top field in a callout is *one
2161        more than* the number of the hightest numbered captured substring.
2163     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2164        in incorrectly linking with a previously installed version. They now link
2165        explicitly with libpcre.la.
2167     5. configure.in no longer needs to recognize Cygwin specially.
2169     6. A problem in pcre.in for Windows platforms is fixed.
2171     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2172        pcretest, it used to include the size of the study block as part of its
2173        output. Unfortunately, the structure contains a field that has a different
2174        size on different hardware architectures. This meant that the tests that
2175        showed this size failed. As the block is currently always of a fixed size,
2176        this information isn't actually particularly useful in pcretest output, so
2177        I have just removed it.
2179     8. Three pre-processor statements accidentally did not start in column 1.
2180        Sadly, there are *still* compilers around that complain, even though
2181        standard C has not required this for well over a decade. Sigh.
2183     9. In pcretest, the code for checking callouts passed small integers in the
2184        callout_data field, which is a void * field. However, some picky compilers
2185        complained about the casts involved for this on 64-bit systems. Now
2186        pcretest passes the address of the small integer instead, which should get
2187        rid of the warnings.
2189    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2190        both compile and run time, and gives an error if an invalid UTF-8 sequence
2191        is found. There is a option for disabling this check in cases where the
2192        string is known to be correct and/or the maximum performance is wanted.
2194    11. In response to a bug report, I changed one line in Makefile.in from
2196            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2197        to
2198            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2200        to look similar to other lines, but I have no way of telling whether this
2201        is the right thing to do, as I do not use Windows. No doubt I'll get told
2202        if it's wrong...
2205    Version 4.3 21-May-03
2206    ---------------------
2208    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2209       Makefile.
2211    2. Some refactoring to improve the quality of the code:
2213       (i)   The utf8_table... variables are now declared "const".
2215       (ii)  The code for \cx, which used the "case flipping" table to upper case
2216             lower case letters, now just substracts 32. This is ASCII-specific,
2217             but the whole concept of \cx is ASCII-specific, so it seems
2218             reasonable.
2220       (iii) PCRE was using its character types table to recognize decimal and
2221             hexadecimal digits in the pattern. This is silly, because it handles
2222             only 0-9, a-f, and A-F, but the character types table is locale-
2223             specific, which means strange things might happen. A private
2224             table is now used for this - though it costs 256 bytes, a table is
2225             much faster than multiple explicit tests. Of course, the standard
2226             character types table is still used for matching digits in subject
2227             strings against \d.
2229       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2230             ending in _t are). So I've renamed it as ESC_tee.
2232    3. The first argument for regexec() in the POSIX wrapper should have been
2233       defined as "const".
2235    4. Changed pcretest to use malloc() for its buffers so that they can be
2236       Electric Fenced for debugging.
2238    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2239       to read one or more bytes before the start of the subject string. Often this
2240       had no effect on PCRE's behaviour, but in some circumstances it could
2241       provoke a segmentation fault.
2243    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2244       to try to read one or more bytes before the start of the subject string.
2246    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2247       UTF-8 support could misbehave in various ways if the subject string
2248       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2249       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2250       back over UTF-8 characters.)
2253    Version 4.2 14-Apr-03
2254    ---------------------
2256    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2258    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2259         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2260         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2261         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2262         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2263           and BUILD_EXEEXT
2264         Note: automatic setting of the BUILD variables is not yet working
2265         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2266           compile-time but not at link-time
2267         [LINK]: use for linking executables only
2268         make different versions for Windows and non-Windows
2269         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2270           libraries
2271         [LINK_FOR_BUILD]: new variable
2272         [OBJEXT]: use throughout
2273         [EXEEXT]: use throughout
2274         <winshared>: new target
2275         <wininstall>: new target
2276         <dftables.o>: use native compiler
2277         <dftables>: use native linker
2278         <install>: handle Windows platform correctly
2279         <clean>: ditto
2280         <check>: ditto
2281         copy DLL to top builddir before testing
2283       As part of these changes, -no-undefined was removed again. This was reported
2284       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2285       in any case.
2287    3. Some tidies to get rid of compiler warnings:
2289       . In the match_data structure, match_limit was an unsigned long int, whereas
2290         match_call_count was an int. I've made them both unsigned long ints.
2292       . In pcretest the fact that a const uschar * doesn't automatically cast to
2293         a void * provoked a warning.
2295       . Turning on some more compiler warnings threw up some "shadow" variables
2296         and a few more missing casts.
2298    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2299       option, a class that contained a single character with a value between 128
2300       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2302    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2303       option, a class that contained several characters, but with at least one
2304       whose value was between 128 and 255 caused PCRE to crash.
2307    Version 4.1 12-Mar-03
2308    ---------------------
2310    1. Compiling with gcc -pedantic found a couple of places where casts were
2311    needed, and a string in dftables.c that was longer than standard compilers are
2312    required to support.
2314    2. Compiling with Sun's compiler found a few more places where the code could
2315    be tidied up in order to avoid warnings.
2317    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2318    first of these names is deprecated in the latest Autoconf in favour of the name
2319    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2320    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2321    analogy I have changed it to CFLAGS_FOR_BUILD.
2323    4. Added -no-undefined to the linking command in the Makefile, because this is
2324    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2325    linking step for the pcreposix library.
2327    5. PCRE was failing to diagnose the case of two named groups with the same
2328    name.
2330    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2331    literal character that is needed in the subject for a match, and scans along to
2332    ensure that it is present before embarking on the full matching process. This
2333    saves time in cases of nested unlimited repeats that are never going to match.
2334    Problem: the scan can take a lot of time if the subject is very long (e.g.
2335    megabytes), thus penalizing straightforward matches. It is now done only if the
2336    amount of subject to be scanned is less than 1000 bytes.
2338    7. A lesser problem with the same optimization is that it was recording the
2339    first character of an anchored pattern as "needed", thus provoking a search
2340    right along the subject, even when the first match of the pattern was going to
2341    fail. The "needed" character is now not set for anchored patterns, unless it
2342    follows something in the pattern that is of non-fixed length. Thus, it still
2343    fulfils its original purpose of finding quick non-matches in cases of nested
2344    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2347    Version 4.0 17-Feb-03
2348    ---------------------
2350    1. If a comment in an extended regex that started immediately after a meta-item
2351    extended to the end of string, PCRE compiled incorrect data. This could lead to
2352    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2354    2. Moved to autoconf 2.53 and libtool 1.4.2.
2356    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2357    the special perltest8 script is no longer needed - all the tests can be run
2358    from a single perltest script.
2360    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2361    by \s. It has now been removed in PCRE. This means it isn't recognized as
2362    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2363    class [:space:] *does* include VT, thereby creating a mess.
2365    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2366    space and tab.
2368    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2369    its new features into the main test script, reducing the number of scripts.
2371    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2372    were backward compatible, and made the (?i) apply to the whole pattern, as if
2373    /i were given. Now it behaves more logically, and applies the option setting
2374    only to what follows. PCRE has been changed to follow suit. However, if it
2375    finds options settings right at the start of the pattern, it extracts them into
2376    the global options, as before. Thus, they show up in the info data.
2378    8. Added support for the \Q...\E escape sequence. Characters in between are
2379    treated as literals. This is slightly different from Perl in that $ and @ are
2380    also handled as literals inside the quotes. In Perl, they will cause variable
2381    interpolation. Note the following examples:
2383        Pattern            PCRE matches      Perl matches
2385        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
2386        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
2387        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
2389    For compatibility with Perl, \Q...\E sequences are recognized inside character
2390    classes as well as outside them.
2392    9. Re-organized 3 code statements in pcretest to avoid "overflow in
2393    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2394    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2395    signed/unsigned warnings.
2397    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2398    option for pcretest, so I've replaced it by a simple function that does just
2399    that job.
2401    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2402    "pcregrep -".
2404    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2405    Java package. This provides some syntactic sugar for simple cases of what my
2406    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2407    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2408    item, you can use this simplified notation. Note that only makes sense with
2409    greedy quantifiers. Consequently, the use of the possessive quantifier forces
2410    greediness, whatever the setting of the PCRE_UNGREEDY option.
2412    13. A change of greediness default within a pattern was not taking effect at
2413    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2414    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2415    was abstracted outside.
2417    14. PCRE now supports the \G assertion. It is true when the current matching
2418    position is at the start point of the match. This differs from \A when the
2419    starting offset is non-zero. Used with the /g option of pcretest (or similar
2420    code), it works in the same way as it does for Perl's /g option. If all
2421    alternatives of a regex begin with \G, the expression is anchored to the start
2422    match position, and the "anchored" flag is set in the compiled expression.
2424    15. Some bugs concerning the handling of certain option changes within patterns
2425    have been fixed. These applied to options other than (?ims). For example,
2426    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2427    been the other way round. Some of this was related to change 7 above.
2429    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2430    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2431    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2432    POSIX classes only within a class (e.g. /[[:alpha:]]/).
2434    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2435    mode. Unlike ".", it always matches newline, whatever the setting of
2436    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2437    assertions. Perl allows it, but it doesn't (in general) work because it can't
2438    calculate the length of the lookbehind. At least, that's the case for Perl
2439    5.8.0 - I've been told they are going to document that it doesn't work in
2440    future.
2442    18. Added an error diagnosis for escapes that PCRE does not support: these are
2443    \L, \l, \N, \P, \p, \U, \u, and \X.
2445    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2446    reading past the end of the pattern in cases such as /[abcd/.
2448    20. PCRE was getting more memory than necessary for patterns with classes that
2449    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2451    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2452    compiling PCRE for use with Virtual Pascal.
2454    22. Small fix to the Makefile to make it work properly if the build is done
2455    outside the source tree.
2457    23. Added a new extension: a condition to go with recursion. If a conditional
2458    subpattern starts with (?(R) the "true" branch is used if recursion has
2459    happened, whereas the "false" branch is used only at the top level.
2461    24. When there was a very long string of literal characters (over 255 bytes
2462    without UTF support, over 250 bytes with UTF support), the computation of how
2463    much memory was required could be incorrect, leading to segfaults or other
2464    strange effects.
2466    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2467    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2468    there was a subsequent back reference to those brackets. This meant that, for
2469    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2470    possible to check for precisely this case. All we can do is abandon the
2471    optimization if .* occurs inside capturing brackets when there are any back
2472    references whatsoever. (See below for a better fix that came later.)
2474    26. The handling of the optimization for finding the first character of a
2475    non-anchored pattern, and for finding a character that is required later in the
2476    match were failing in some cases. This didn't break the matching; it just
2477    failed to optimize when it could. The way this is done has been re-implemented.
2479    27. Fixed typo in error message for invalid (?R item (it said "(?p").
2481    28. Added a new feature that provides some of the functionality that Perl
2482    provides with (?{...}). The facility is termed a "callout". The way it is done
2483    in PCRE is for the caller to provide an optional function, by setting
2484    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2485    global variable. By default it is unset, which disables all calling out. To get
2486    the function called, the regex must include (?C) at appropriate points. This
2487    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2488    This provides a means of identifying different callout points. When PCRE
2489    reaches such a point in the regex, if pcre_callout has been set, the external
2490    function is called. It is provided with data in a structure called
2491    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2492    matching continues; if it returns a non-zero value, the match at the current
2493    point fails. However, backtracking will occur if possible. [This was changed
2494    later and other features added - see item 49 below.]
2496    29. pcretest is upgraded to test the callout functionality. It provides a
2497    callout function that displays information. By default, it shows the start of
2498    the match and the current position in the text. There are some new data escapes
2499    to vary what happens:
2501        \C+         in addition, show current contents of captured substrings
2502        \C-         do not supply a callout function
2503        \C!n        return 1 when callout number n is reached
2504        \C!n!m      return 1 when callout number n is reached for the mth time
2506    30. If pcregrep was called with the -l option and just a single file name, it
2507    output "<stdin>" if a match was found, instead of the file name.
2509    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2510    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2511    pcre_exec(). This saves a malloc/free per call. The default value of
2512    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2513    when configuring.
2515    32. The default maximum size of a compiled pattern is 64K. There have been a
2516    few cases of people hitting this limit. The code now uses macros to handle the
2517    storing of links as offsets within the compiled pattern. It defaults to 2-byte
2518    links, but this can be changed to 3 or 4 bytes by --with-link-size when
2519    configuring. Tests 2 and 5 work only with 2-byte links because they output
2520    debugging information about compiled patterns.
2522    33. Internal code re-arrangements:
2524    (a) Moved the debugging function for printing out a compiled regex into
2525        its own source file (printint.c) and used #include to pull it into
2526        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2527        separate copies.
2529    (b) Defined the list of op-code names for debugging as a macro in
2530        internal.h so that it is next to the definition of the opcodes.
2532    (c) Defined a table of op-code lengths for simpler skipping along compiled
2533        code. This is again a macro in internal.h so that it is next to the
2534        definition of the opcodes.
2536    34. Added support for recursive calls to individual subpatterns, along the
2537    lines of Robin Houston's patch (but implemented somewhat differently).
2539    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2540    allow it to read and process whole directories in Win32. This code was
2541    contributed by Lionel Fourquaux; it has not been tested by me.
2543    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2544    used to name a group. Names consist of alphanumerics and underscores, and must
2545    be unique. Back references use the syntax (?P=name) and recursive calls use
2546    (?P>name) which is a PCRE extension to the Python extension. Groups still have
2547    numbers. The function pcre_fullinfo() can be used after compilation to extract
2548    a name/number map. There are three relevant calls:
2550      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
2551      PCRE_INFO_NAMECOUNT            yields the number of entries
2552      PCRE_INFO_NAMETABLE            yields a pointer to the map.
2554    The map is a vector of fixed-size entries. The size of each entry depends on
2555    the length of the longest name used. The first two bytes of each entry are the
2556    group number, most significant byte first. There follows the corresponding
2557    name, zero terminated. The names are in alphabetical order.
2559    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2560    case instead of 255. Making it the same both with and without UTF-8 support
2561    means that the same test output works with both.
2563    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2564    calling malloc() with a zero argument.
2566    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2567    optimization. I've improved things by keeping a bitmap of backreferences with
2568    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2569    fact referenced, the optimization can be applied. It is unlikely that a
2570    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2571    the match to follow \n) will appear inside brackets with a number greater than
2572    31, but if it does, any back reference > 31 suppresses the optimization.
2574    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2575    of disabling numbered capturing parentheses. Any opening parenthesis that is
2576    not followed by ? behaves as if it were followed by ?: but named parentheses
2577    can still be used for capturing (and they will acquire numbers in the usual
2578    way).
2580    41. Redesigned the return codes from the match() function into yes/no/error so
2581    that errors can be passed back from deep inside the nested calls. A malloc
2582    failure while inside a recursive subpattern call now causes the
2583    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2585    42. It is now possible to set a limit on the number of times the match()
2586    function is called in a call to pcre_exec(). This facility makes it possible to
2587    limit the amount of recursion and backtracking, though not in a directly
2588    obvious way, because the match() function is used in a number of different
2589    circumstances. The count starts from zero for each position in the subject
2590    string (for non-anchored patterns). The default limit is, for compatibility, a
2591    large number, namely 10 000 000. You can change this in two ways:
2593    (a) When configuring PCRE before making, you can use --with-match-limit=n
2594        to set a default value for the compiled library.
2596    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2597        a different value is set. See 45 below.
2599    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2601    43. Added a new function pcre_config(int, void *) to enable run-time extraction
2602    of things that can be changed at compile time. The first argument specifies
2603    what is wanted and the second points to where the information is to be placed.
2604    The current list of available information is:
2606      PCRE_CONFIG_UTF8
2608    The output is an integer that is set to one if UTF-8 support is available;
2609    otherwise it is set to zero.
2613    The output is an integer that it set to the value of the code that is used for
2614    newline. It is either LF (10) or CR (13).
2618    The output is an integer that contains the number of bytes used for internal
2619    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2623    The output is an integer that contains the threshold above which the POSIX
2624    interface uses malloc() for output vectors. See item 31 above.
2628    The output is an unsigned integer that contains the default limit of the number
2629    of match() calls in a pcre_exec() execution. See 42 above.
2631    44. pcretest has been upgraded by the addition of the -C option. This causes it
2632    to extract all the available output from the new pcre_config() function, and to
2633    output it. The program then exits immediately.
2635    45. A need has arisen to pass over additional data with calls to pcre_exec() in
2636    order to support additional features. One way would have been to define
2637    pcre_exec2() (for example) with extra arguments, but this would not have been
2638    extensible, and would also have required all calls to the original function to
2639    be mapped to the new one. Instead, I have chosen to extend the mechanism that
2640    is used for passing in "extra" data from pcre_study().
2642    The pcre_extra structure is now exposed and defined in pcre.h. It currently
2643    contains the following fields:
2645      flags         a bitmap indicating which of the following fields are set
2646      study_data    opaque data from pcre_study()
2647      match_limit   a way of specifying a limit on match() calls for a specific
2648                      call to pcre_exec()
2649      callout_data  data for callouts (see 49 below)
2651    The flag bits are also defined in pcre.h, and are
2657    The pcre_study() function now returns one of these new pcre_extra blocks, with
2658    the actual study data pointed to by the study_data field, and the
2659    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2660    before. That is, this change is entirely upwards-compatible and requires no
2661    change to existing code.
2663    If you want to pass in additional data to pcre_exec(), you can either place it
2664    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2665    block.
2667    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2668    data string contains the escape sequence \M, pcretest calls pcre_exec() several
2669    times with different match limits, until it finds the minimum value needed for
2670    pcre_exec() to complete. The value is then output. This can be instructive; for
2671    most simple matches the number is quite small, but for pathological cases it
2672    gets very large very quickly.
2674    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2675    returns the size of the data block pointed to by the study_data field in a
2676    pcre_extra block, that is, the value that was passed as the argument to
2677    pcre_malloc() when PCRE was getting memory in which to place the information
2678    created by pcre_study(). The fourth argument should point to a size_t variable.
2679    pcretest has been extended so that this information is shown after a successful
2680    pcre_study() call when information about the compiled regex is being displayed.
2682    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2683    because what follows is always an absolute path. (Later: it turns out that this
2684    is more than cosmetic for MinGW, because it doesn't like empty path
2685    components.)
2687    49. Some changes have been made to the callout feature (see 28 above):
2689    (i)  A callout function now has three choices for what it returns:
2691           0  =>  success, carry on matching
2692         > 0  =>  failure at this point, but backtrack if possible
2693         < 0  =>  serious error, return this value from pcre_exec()
2695         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2696         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2697         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2698         use by callout functions. It will never be used by PCRE itself.
2700    (ii) The pcre_extra structure (see 45 above) has a void * field called
2701         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2702         pcre_callout_block structure has a field of the same name. The contents of
2703         the field passed in the pcre_extra structure are passed to the callout
2704         function in the corresponding field in the callout block. This makes it
2705         easier to use the same callout-containing regex from multiple threads. For
2706         testing, the pcretest program has a new data escape
2708           \C*n        pass the number n (may be negative) as callout_data
2710         If the callout function in pcretest receives a non-zero value as
2711         callout_data, it returns that value.
2713    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2714    there were some redundant $(CFLAGS) in commands that are now specified as
2715    $(LINK), which already includes $(CFLAGS).
2717    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2718    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2719    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2720    one-byte characters throughout. Note that case-insensitive matching applies
2721    only to characters whose values are less than 256. PCRE doesn't support the
2722    notion of cases for higher-valued characters.
2724    (i)   A character class whose characters are all within 0-255 is handled as
2725          a bit map, and the map is inverted for negative classes. Previously, a
2726          character > 255 always failed to match such a class; however it should
2727          match if the class was a negative one (e.g. [^ab]). This has been fixed.
2729    (ii)  A negated character class with a single character < 255 is coded as
2730          "not this character" (OP_NOT). This wasn't working properly when the test
2731          character was multibyte, either singly or repeated.
2733    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2734          mode, for example: \x{100}{2,3}.
2736    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2737          singly or repeated) now correctly test multibyte characters. However,
2738          PCRE doesn't recognize any characters with values greater than 255 as
2739          digits, spaces, or word characters. Such characters always match \D, \S,
2740          and \W, and never match \d, \s, or \w.
2742    (v)   Classes may now contain characters and character ranges with values
2743          greater than 255. For example: [ab\x{100}-\x{400}].
2745    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
2746          PCRE in UTF-8 mode.
2748    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2749    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2750    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2751    value.)
2753    53. The single man page has become too large. I have therefore split it up into
2754    a number of separate man pages. These also give rise to individual HTML pages;
2755    these are now put in a separate directory, and there is an index.html page that
2756    lists them all. Some hyperlinking between the pages has been installed.
2758    54. Added convenience functions for handling named capturing parentheses.
2760    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2761    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2762    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2763    are faulted.
2765    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2766    calling configure. These values are used when compiling the dftables.c program
2767    which is run to generate the source of the default character tables. They
2768    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2769    you will need to set these values.
2771    57. Updated the building process for Windows DLL, as provided by Fred Cox.
2774    Version 3.9 02-Jan-02
2775    ---------------------
2777    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2779    2. If --disable-static was given, the building process failed when trying to
2780    build pcretest and pcregrep. (For some reason it was using libtool to compile
2781    them, which is not right, as they aren't part of the library.)
2784    Version 3.8 18-Dec-01
2785    ---------------------
2787    1. The experimental UTF-8 code was completely screwed up. It was packing the
2788    bytes in the wrong order. How dumb can you get?
2791    Version 3.7 29-Oct-01
2792    ---------------------
2794    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2795    This caused pcretest, when used on the test data, to segfault. Unfortunately,
2796    this didn't happen under Solaris 8, where I normally test things.
2798    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2799    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2800    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2801    this fix an hour or so after the initial 3.7 release.)
2804    Version 3.6 23-Oct-01
2805    ---------------------
2807    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2808    offsets passed as NULL with zero offset count.
2810    2. The config.guess and config.sub files had not been updated when I moved to
2811    the latest autoconf.
2814    Version 3.5 15-Aug-01
2815    ---------------------
2817    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2818    had been forgotten.
2820    2. By using declared but undefined structures, we can avoid using "void"
2821    definitions in pcre.h while keeping the internal definitions of the structures
2822    private.
2824    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2825    user point of view, this means that both static and shared libraries are built
2826    by default, but this can be individually controlled. More of the work of
2827    handling this static/shared cases is now inside libtool instead of PCRE's make
2828    file.
2830    4. The pcretest utility is now installed along with pcregrep because it is
2831    useful for users (to test regexs) and by doing this, it automatically gets
2832    relinked by libtool. The documentation has been turned into a man page, so
2833    there are now .1, .txt, and .html versions in /doc.
2835    5. Upgrades to pcregrep:
2836       (i)   Added long-form option names like gnu grep.
2837       (ii)  Added --help to list all options with an explanatory phrase.
2838       (iii) Added -r, --recursive to recurse into sub-directories.
2839       (iv)  Added -f, --file to read patterns from a file.
2841    6. pcre_exec() was referring to its "code" argument before testing that
2842    argument for NULL (and giving an error if it was NULL).
2844    7. Upgraded Makefile.in to allow for compiling in a different directory from
2845    the source directory.
2847    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2848    options bits, the pointer it was passed was to an int instead of to an unsigned
2849    long int. This mattered only on 64-bit systems.
2851    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2852    generated) instead of pcre.in, which it its source. Also made the same change
2853    in several of the .c files.
2855    10. A new release of gcc defines printf() as a macro, which broke pcretest
2856    because it had an ifdef in the middle of a string argument for printf(). Fixed
2857    by using separate calls to printf().
2859    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2860    script, to force use of CR or LF instead of \n in the source. On non-Unix
2861    systems, the value can be set in config.h.
2863    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2864    absolute limit. Changed the text of the error message to make this clear, and
2865    likewise updated the man page.
2867    13. The limit of 99 on the number of capturing subpatterns has been removed.
2868    The new limit is 65535, which I hope will not be a "real" limit.
2871    Version 3.4 22-Aug-00
2872    ---------------------
2874    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2876    2. Diagnose condition (?(0) as an error instead of crashing on matching.
2879    Version 3.3 01-Aug-00
2880    ---------------------
2882    1. If an octal character was given, but the value was greater than \377, it
2883    was not getting masked to the least significant bits, as documented. This could
2884    lead to crashes in some systems.
2886    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2887    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2889    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2890    These just pass their arguments on to (pcre_free)(), but they are provided
2891    because some uses of PCRE bind it to non-C systems that can call its functions,
2892    but cannot call free() or pcre_free() directly.
2894    4. Add "make test" as a synonym for "make check". Corrected some comments in
2895    the Makefile.
2897    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2898    Makefile.
2900    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2901    command called pgrep for grepping around the active processes.
2903    7. Added the beginnings of support for UTF-8 character strings.
2905    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2906    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2907    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2908    out for the ar command.)
2911    Version 3.2 12-May-00
2912    ---------------------
2914    This is purely a bug fixing release.
2916    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2917    of ZA. This was just one example of several cases that could provoke this bug,
2918    which was introduced by change 9 of version 2.00. The code for breaking
2919    infinite loops after an iteration that matches an empty string was't working
2920    correctly.
2922    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2923    when matched against abbab (for example). After matching an empty string, it
2924    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2925    caused it to match further down the string than it should.
2927    3. The code contained an inclusion of sys/types.h. It isn't clear why this
2928    was there because it doesn't seem to be needed, and it causes trouble on some
2929    systems, as it is not a Standard C header. It has been removed.
2931    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2932    were reported on the Macintosh. The changes were from
2934      while ((c = *(++ptr)) != 0 && c != '\n');
2935    to
2936      while ((c = *(++ptr)) != 0 && c != '\n') ;
2938    Totally extraordinary, but if that's what it takes...
2940    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2941    available. Added HAVE_BCOPY and an autoconf test for it; if neither
2942    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2943    assumes the way PCRE uses memmove() (always moving upwards).
2945    6. PCRE is being used in one environment where strchr() is not available. There
2946    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2947    faster code anyway.
2950    Version 3.1 09-Feb-00
2951    ---------------------
2953    The only change in this release is the fixing of some bugs in Makefile.in for
2954    the "install" target:
2956    (1) It was failing to install pcreposix.h.
2958    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2961    Version 3.0 01-Feb-00
2962    ---------------------
2964    1. Add support for the /+ modifier to perltest (to output $` like it does in
2965    pcretest).
2967    2. Add support for the /g modifier to perltest.
2969    3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2970    matches null strings.
2972    4. Fix perltest so that it doesn't do unwanted things when fed an empty
2973    pattern. Perl treats empty patterns specially - it reuses the most recent
2974    pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2975    effect.
2977    5. The POSIX interface was broken in that it was just handing over the POSIX
2978    captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2979    required a bigger vector, with some working space on the end. This means that
2980    the POSIX wrapper now has to get and free some memory, and copy the results.
2982    6. Added some simple autoconf support, placing the test data and the
2983    documentation in separate directories, re-organizing some of the
2984    information files, and making it build pcre-config (a GNU standard). Also added
2985    libtool support for building PCRE as a shared library, which is now the
2986    default.
2988    7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2989    09 are not valid octal constants. Single digits will be used for minor values
2990    less than 10.
2992    8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2993    existing programs that set these in the POSIX interface can use PCRE without
2994    modification.
2996    9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2997    return all that pcre_info() returns, plus additional data. The pcre_info()
2998    function is retained for compatibility, but is considered to be obsolete.
3000    10. Added experimental recursion feature (?R) to handle one common case that
3001    Perl 5.6 will be able to do with (?p{...}).
3003    11. Added support for POSIX character classes like [:alpha:], which Perl is
3004    adopting.
3007    Version 2.08 31-Aug-99
3008    ----------------------
3010    1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3011    trying to match at the startoffset position, but instead was moving forward to
3012    the next newline as if a previous match had failed.
3014    2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3015    and could get into a loop if a null string was matched other than at the start
3016    of the subject.
3018    3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3019    be distinguished at compile time, and for completeness also added PCRE_DATE.
3021    5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3022    in GnuWin32 environments.
3025    Version 2.07 29-Jul-99
3026    ----------------------
3028    1. The documentation is now supplied in plain text form and HTML as well as in
3029    the form of man page sources.
3031    2. C++ compilers don't like assigning (void *) values to other pointer types.
3032    In particular this affects malloc(). Although there is no problem in Standard
3033    C, I've put in casts to keep C++ compilers happy.
3035    3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3036    should be (const char *).
3038    4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3039    be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3040    However, I haven't made this a standard facility. The documentation doesn't
3041    mention it, and the Makefile doesn't support it.
3043    5. The Makefile now contains an "install" target, with editable destinations at
3044    the top of the file. The pcretest program is not installed.
3046    6. pgrep -V now gives the PCRE version number and date.
3048    7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3049    causing the entire string to be ignored, instead of just the last character.
3051    8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3052    non-matching string, it can take a very, very long time, even for strings of
3053    quite modest length, because of the nested recursion. PCRE now does better in
3054    some of these cases. It does this by remembering the last required literal
3055    character in the pattern, and pre-searching the subject to ensure it is present
3056    before running the real match. In other words, it applies a heuristic to detect
3057    some types of certain failure quickly, and in the above example, if presented
3058    with a string that has no trailing " it gives "no match" very quickly.
3060    9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3061    other alternatives are tried instead.
3064    Version 2.06 09-Jun-99
3065    ----------------------
3067    1. Change pcretest's output for amount of store used to show just the code
3068    space, because the remainder (the data block) varies in size between 32-bit and
3069    64-bit systems.
3071    2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3072    start matching at. This allows lookbehinds to work when searching for multiple
3073    occurrences in a string.
3075    3. Added additional options to pcretest for testing multiple occurrences:
3077       /+   outputs the rest of the string that follows a match
3078       /g   loops for multiple occurrences, using the new startoffset argument
3079       /G   loops for multiple occurrences by passing an incremented pointer
3081    4. PCRE wasn't doing the "first character" optimization for patterns starting
3082    with \b or \B, though it was doing it for other lookbehind assertions. That is,
3083    it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3084    the letter 'x'. On long subject strings, this gives a significant speed-up.
3087  Version 2.05 21-Apr-99  Version 2.05 21-Apr-99
3088  ----------------------  ----------------------

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