/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

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

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

Legend:
Removed from v.35  
changed lines
  Added in v.377

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12