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

Diff of /code/trunk/ChangeLog

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

revision 87 by nigel, Sat Feb 24 21:41:21 2007 UTC revision 402 by ph10, Sat Mar 21 17:26:03 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.  In pcregrep, when --colour was used with -o, the list of matching strings
28        was not coloured; this is different to GNU grep, so I have changed it to be
29        the same.
30    
31    6.  When --colo(u)r was used in pcregrep, only the first matching substring in
32        each matching line was coloured. Now it goes on to look for further matches
33        of any of the test patterns, which is the same behaviour as GNU grep.
34    
35    7.  A pattern that could match an empty string could cause pcregrep to loop; it
36        doesn't make sense to accept an empty string match in pcregrep, so I have
37        locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
38        seems to be how GNU grep behaves.
39    
40    8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
41        start or after a newline", because the conditional assertion was not being
42        correctly handled. The rule now is that both the assertion and what follows
43        in the first alternative must satisfy the test.
44    
45    9.  If auto-callout was enabled in a pattern with a conditional group whose
46        condition was an assertion, PCRE could crash during matching, both with
47        pcre_exec() and pcre_dfa_exec().
48    
49    10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
50        used for matching.
51    
52    11. Unicode property support in character classes was not working for
53        characters (bytes) greater than 127 when not in UTF-8 mode.
54    
55    12. Added the -M command line option to pcretest.
56    
57    14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
58    
59    15. Added the PCRE_NO_START_OPTIMIZE match-time option.
60    
61    16. Added comments and documentation about mis-use of no_arg in the C++
62        wrapper.
63    
64    17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
65        from Martin Jerabek that uses macro names for all relevant character and
66        string constants.
67    
68    18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
69        SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
70        SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
71        these, but not everybody uses configure.
72    
73    19. A conditional group that had only one branch was not being correctly
74        recognized as an item that could match an empty string. This meant that an
75        enclosing group might also not be so recognized, causing infinite looping
76        (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
77        with the subject "ab", where knowledge that the repeated group can match
78        nothing is needed in order to break the loop.
79    
80    20. If a pattern that was compiled with callouts was matched using pcre_dfa_
81        exec(), but without supplying a callout function, matching went wrong.
82    
83    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
84        leak if the size of the offset vector was greater than 30. When the vector
85        is smaller, the saved offsets during recursion go onto a local stack
86        vector, but for larger vectors malloc() is used. It was failing to free
87        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
88        error, in fact).
89    
90    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
91        heapframe that is used only when UTF-8 support is enabled. This caused no
92        problem, but was untidy.
93    
94    
95    Version 7.8 05-Sep-08
96    ---------------------
97    
98    1.  Replaced UCP searching code with optimized version as implemented for Ad
99        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
100        stage table and inline lookup instead of a function, giving speed ups of 2
101        to 5 times on some simple patterns that I tested. Permission was given to
102        distribute the MultiStage2.py script that generates the tables (it's not in
103        the tarball, but is in the Subversion repository).
104    
105    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
106        scripts.
107    
108    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
109        a group with a zero qualifier. The result of the study could be incorrect,
110        or the function might crash, depending on the pattern.
111    
112    4.  Caseless matching was not working for non-ASCII characters in back
113        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
114        It now works when Unicode Property Support is available.
115    
116    5.  In pcretest, an escape such as \x{de} in the data was always generating
117        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
118        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
119        truncation.
120    
121    6.  Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
122    
123    7.  Added two (int) casts to pcregrep when printing the difference of two
124        pointers, in case they are 64-bit values.
125    
126    8.  Added comments about Mac OS X stack usage to the pcrestack man page and to
127        test 2 if it fails.
128    
129    9.  Added PCRE_CALL_CONVENTION just before the names of all exported functions,
130        and a #define of that name to empty if it is not externally set. This is to
131        allow users of MSVC to set it if necessary.
132    
133    10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
134        the convenience functions in the pcre_get.c source file.
135    
136    11. An option change at the start of a pattern that had top-level alternatives
137        could cause overwriting and/or a crash. This command provoked a crash in
138        some environments:
139    
140          printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
141    
142        This potential security problem was recorded as CVE-2008-2371.
143    
144    12. For a pattern where the match had to start at the beginning or immediately
145        after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
146        pcre_dfa_exec() could read past the end of the passed subject if there was
147        no match. To help with detecting such bugs (e.g. with valgrind), I modified
148        pcretest so that it places the subject at the end of its malloc-ed buffer.
149    
150    13. The change to pcretest in 12 above threw up a couple more cases when pcre_
151        exec() might read past the end of the data buffer in UTF-8 mode.
152    
153    14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
154        the data contained the byte 0x85 as part of a UTF-8 character within its
155        first line. This applied both to normal and DFA matching.
156    
157    15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
158        /^[^d]*?$/8 failed to match "abc".
159    
160    16. Added a missing copyright notice to pcrecpp_internal.h.
161    
162    17. Make it more clear in the documentation that values returned from
163        pcre_exec() in ovector are byte offsets, not character counts.
164    
165    18. Tidied a few places to stop certain compilers from issuing warnings.
166    
167    19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
168        supplied by Stefan Weber. I made a further small update for 7.8 because
169        there is a change of source arrangements: the pcre_searchfuncs.c module is
170        replaced by pcre_ucd.c.
171    
172    
173    Version 7.7 07-May-08
174    ---------------------
175    
176    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
177        a string to a long long, pretend we don't even have a long long." This is
178        done by checking for the strtoq, strtoll, and _strtoi64 functions.
179    
180    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
181        pre-7.6 versions, which defined a global no_arg variable instead of putting
182        it in the RE class. (See also #8 below.)
183    
184    3.  Remove a line of dead code, identified by coverity and reported by Nuno
185        Lopes.
186    
187    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
188    
189        (1) The include/exclude patterns were being applied to the whole pathnames
190            of files, instead of just to the final components.
191    
192        (2) If there was more than one level of directory, the subdirectories were
193            skipped unless they satisfied the include/exclude conditions. This is
194            inconsistent with GNU grep (and could even be seen as contrary to the
195            pcregrep specification - which I improved to make it absolutely clear).
196            The action now is always to scan all levels of directory, and just
197            apply the include/exclude patterns to regular files.
198    
199    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
200        --exclude_dir in the tests to avoid scanning .svn directories.
201    
202    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
203        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
204        doesn't support NULs in patterns.
205    
206    7.  Added some missing "const"s to declarations of static tables in
207        pcre_compile.c and pcre_dfa_exec.c.
208    
209    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
210        caused by fix #2  above. (Subsequently also a second patch to fix the
211        first patch. And a third patch - this was a messy problem.)
212    
213    9.  Applied Craig's patch to remove the use of push_back().
214    
215    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
216        matching function regexec().
217    
218    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
219        which, however, unlike Perl's \g{...}, are subroutine calls, not back
220        references. PCRE supports relative numbers with this syntax (I don't think
221        Oniguruma does).
222    
223    12. Previously, a group with a zero repeat such as (...){0} was completely
224        omitted from the compiled regex. However, this means that if the group
225        was called as a subroutine from elsewhere in the pattern, things went wrong
226        (an internal error was given). Such groups are now left in the compiled
227        pattern, with a new opcode that causes them to be skipped at execution
228        time.
229    
230    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
231        to the way PCRE behaves:
232    
233        (a) A lone ] character is dis-allowed (Perl treats it as data).
234    
235        (b) A back reference to an unmatched subpattern matches an empty string
236            (Perl fails the current match path).
237    
238        (c) A data ] in a character class must be notated as \] because if the
239            first data character in a class is ], it defines an empty class. (In
240            Perl it is not possible to have an empty class.) The empty class []
241            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
242            The negative empty class [^] matches any one character, independently
243            of the DOTALL setting.
244    
245    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
246        non-existent subpattern following a character class starting with ']' and
247        containing () gave an internal compiling error instead of "reference to
248        non-existent subpattern". Fortunately, when the pattern did exist, the
249        compiled code was correct. (When scanning forwards to check for the
250        existencd of the subpattern, it was treating the data ']' as terminating
251        the class, so got the count wrong. When actually compiling, the reference
252        was subsequently set up correctly.)
253    
254    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
255        it was being rejected as not supported by pcre_dfa_exec(), even though
256        other assertions are supported. I have made pcre_dfa_exec() support
257        (*FAIL).
258    
259    16. The implementation of 13c above involved the invention of a new opcode,
260        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
261        cannot be changed at match time, I realized I could make a small
262        improvement to matching performance by compiling OP_ALLANY instead of
263        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
264        on the OP_ANY path.
265    
266    17. Compiling pcretest on Windows with readline support failed without the
267        following two fixes: (1) Make the unistd.h include conditional on
268        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
269    
270    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
271        ncurses library to be included for pcretest when ReadLine support is
272        requested, but also to allow for it to be overridden. This patch came from
273        Daniel Bergström.
274    
275    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
276        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
277        any errors with the current Unicode tables. Thanks to Peter Kankowski for
278        spotting this.
279    
280    
281    Version 7.6 28-Jan-08
282    ---------------------
283    
284    1.  A character class containing a very large number of characters with
285        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
286        overflow.
287    
288    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
289        HAVE_LONG_LONG is not defined.
290    
291    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
292        bring them up to date and include new features. This patch includes:
293    
294        - Fixed PH's badly added libz and libbz2 support.
295        - Fixed a problem with static linking.
296        - Added pcredemo. [But later removed - see 7 below.]
297        - Fixed dftables problem and added an option.
298        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
299            HAVE_LONG_LONG.
300        - Added readline support for pcretest.
301        - Added an listing of the option settings after cmake has run.
302    
303    4.  A user submitted a patch to Makefile that makes it easy to create
304        "pcre.dll" under mingw when using Configure/Make. I added stuff to
305        Makefile.am that cause it to include this special target, without
306        affecting anything else. Note that the same mingw target plus all
307        the other distribution libraries and programs are now supported
308        when configuring with CMake (see 6 below) instead of with
309        Configure/Make.
310    
311    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
312        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
313        exported in the Windows port". It has not yet been confirmed that the patch
314        solves the problem, but it does no harm.
315    
316    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
317        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
318        with CMake, and also correct the comment about stack recursion.
319    
320    7.  Remove the automatic building of pcredemo from the ./configure system and
321        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
322        of a program that users should build themselves after PCRE is installed, so
323        building it automatically is not really right. What is more, it gave
324        trouble in some build environments.
325    
326    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
327    
328    
329    Version 7.5 10-Jan-08
330    ---------------------
331    
332    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
333        values in parens when parsing an RE using the C++ wrapper."
334    
335    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
336        Characters greater than 255 were excluded from the class instead of being
337        included.
338    
339    3.  The same bug as (2) above applied to negated POSIX classes such as
340        [:^space:].
341    
342    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
343        defined or documented. It seems to have been a typo for PCRE_STATIC, so
344        I have changed it.
345    
346    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
347        first named subpattern) and a construct such as (?&a) would reference the
348        first named subpattern whose name started with "a" (in other words, the
349        length check was missing). Both these problems are fixed. "Subpattern name
350        expected" is now given for (?&) (a zero-length name), and this patch also
351        makes it give the same error for \k'' (previously it complained that that
352        was a reference to a non-existent subpattern).
353    
354    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
355        this is right because (?- can be followed by option settings as well as by
356        digits. I have, however, made the messages clearer.
357    
358    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
359        than the number used in the conditional) now cause a compile-time error.
360        This is actually not compatible with Perl, which accepts such patterns, but
361        treats the conditional as always being FALSE (as PCRE used to), but it
362        seems to me that giving a diagnostic is better.
363    
364    8.  Change "alphameric" to the more common word "alphanumeric" in comments
365        and messages.
366    
367    9.  Fix two occurrences of "backslash" in comments that should have been
368        "backspace".
369    
370    10. Remove two redundant lines of code that can never be obeyed (their function
371        was moved elsewhere).
372    
373    11. The program that makes PCRE's Unicode character property table had a bug
374        which caused it to generate incorrect table entries for sequences of
375        characters that have the same character type, but are in different scripts.
376        It amalgamated them into a single range, with the script of the first of
377        them. In other words, some characters were in the wrong script. There were
378        thirteen such cases, affecting characters in the following ranges:
379    
380          U+002b0 - U+002c1
381          U+0060c - U+0060d
382          U+0061e - U+00612
383          U+0064b - U+0065e
384          U+0074d - U+0076d
385          U+01800 - U+01805
386          U+01d00 - U+01d77
387          U+01d9b - U+01dbf
388          U+0200b - U+0200f
389          U+030fc - U+030fe
390          U+03260 - U+0327f
391          U+0fb46 - U+0fbb1
392          U+10450 - U+1049d
393    
394    12. The -o option (show only the matching part of a line) for pcregrep was not
395        compatible with GNU grep in that, if there was more than one match in a
396        line, it showed only the first of them. It now behaves in the same way as
397        GNU grep.
398    
399    13. If the -o and -v options were combined for pcregrep, it printed a blank
400        line for every non-matching line. GNU grep prints nothing, and pcregrep now
401        does the same. The return code can be used to tell if there were any
402        non-matching lines.
403    
404    14. Added --file-offsets and --line-offsets to pcregrep.
405    
406    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
407        infinitely looping recursion. The bug was that positive lookaheads were not
408        being skipped when checking for a possible empty match (negative lookaheads
409        and both kinds of lookbehind were skipped).
410    
411    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
412        inclusion of <windows.h> to before rather than after the definition of
413        INVALID_FILE_ATTRIBUTES (patch from David Byron).
414    
415    17. Specifying a possessive quantifier with a specific limit for a Unicode
416        character property caused pcre_compile() to compile bad code, which led at
417        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
418        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
419        caused the error; without that there was no problem.
420    
421    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
422    
423    19. Added --enable-pcretest-libreadline.
424    
425    20. In pcrecpp.cc, the variable 'count' was incremented twice in
426        RE::GlobalReplace(). As a result, the number of replacements returned was
427        double what it should be. I removed one of the increments, but Craig sent a
428        later patch that removed the other one (the right fix) and added unit tests
429        that check the return values (which was not done before).
430    
431    21. Several CMake things:
432    
433        (1) Arranged that, when cmake is used on Unix, the libraries end up with
434            the names libpcre and libpcreposix, not just pcre and pcreposix.
435    
436        (2) The above change means that pcretest and pcregrep are now correctly
437            linked with the newly-built libraries, not previously installed ones.
438    
439        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
440    
441    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
442        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
443        UTF-8 newline character). The key issue is that the pattern starts .*;
444        this means that the match must be either at the beginning, or after a
445        newline. The bug was in the code for advancing after a failed match and
446        checking that the new position followed a newline. It was not taking
447        account of UTF-8 characters correctly.
448    
449    23. PCRE was behaving differently from Perl in the way it recognized POSIX
450        character classes. PCRE was not treating the sequence [:...:] as a
451        character class unless the ... were all letters. Perl, however, seems to
452        allow any characters between [: and :], though of course it rejects as
453        unknown any "names" that contain non-letters, because all the known class
454        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
455        for example, whereas PCRE did not - it did not recognize a POSIX character
456        class. This seemed a bit dangerous, so the code has been changed to be
457        closer to Perl. The behaviour is not identical to Perl, because PCRE will
458        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
459        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
460        Perl does, and where it didn't before.
461    
462    24. Rewrite so as to remove the single use of %n from pcregrep because in some
463        Windows environments %n is disabled by default.
464    
465    
466    Version 7.4 21-Sep-07
467    ---------------------
468    
469    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
470        means that a class such as [\s] counted as "explicit reference to CR or
471        LF". That isn't really right - the whole point of the change was to try to
472        help when there was an actual mention of one of the two characters. So now
473        the change happens only if \r or \n (or a literal CR or LF) character is
474        encountered.
475    
476    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
477        of both had grown to the point where there were only 3 bits left.
478        Fortunately, there was spare space in the data structure, and so I have
479        moved the internal flags into a new 16-bit field to free up more option
480        bits.
481    
482    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
483        but did not set the internal JCHANGED flag - either of these is enough to
484        control the way the "get" function works - but the PCRE_INFO_JCHANGED
485        facility is supposed to tell if (?J) was ever used, so now (?J) at the
486        start sets both bits.
487    
488    4.  Added options (at build time, compile time, exec time) to change \R from
489        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
490    
491    5.  doc/pcresyntax.html was missing from the distribution.
492    
493    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
494        compatibility, even though it is no longer used.
495    
496    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
497        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
498        windows.h file is present (where different names are used). [This was
499        reversed later after testing - see 16 below.]
500    
501    8.  Changed all #include <config.h> to #include "config.h". There were also
502        some further <pcre.h> cases that I changed to "pcre.h".
503    
504    9.  When pcregrep was used with the --colour option, it missed the line ending
505        sequence off the lines that it output.
506    
507    10. It was pointed out to me that arrays of string pointers cause lots of
508        relocations when a shared library is dynamically loaded. A technique of
509        using a single long string with a table of offsets can drastically reduce
510        these. I have refactored PCRE in four places to do this. The result is
511        dramatic:
512    
513          Originally:                          290
514          After changing UCP table:            187
515          After changing error message table:   43
516          After changing table of "verbs"       36
517          After changing table of Posix names   22
518    
519        Thanks to the folks working on Gregex for glib for this insight.
520    
521    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
522        unicode-properties was also set.
523    
524    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
525    
526    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
527        checked only for CRLF.
528    
529    14. Added casts to pcretest.c to avoid compiler warnings.
530    
531    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
532    
533    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
534        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
535        entirely. This removes changes made in 7 above.
536    
537    17. The CMake files have been updated, and there is now more information about
538        building with CMake in the NON-UNIX-USE document.
539    
540    
541    Version 7.3 28-Aug-07
542    ---------------------
543    
544     1. In the rejigging of the build system that eventually resulted in 7.1, the
545        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
546        brackets there is not right, since it causes compilers to look for an
547        installed pcre.h, not the version that is in the source that is being
548        compiled (which of course may be different). I have changed it back to:
549    
550          #include "pcre.h"
551    
552        I have a vague recollection that the change was concerned with compiling in
553        different directories, but in the new build system, that is taken care of
554        by the VPATH setting the Makefile.
555    
556     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
557        when the subject happened to end in the byte 0x85 (e.g. if the last
558        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
559        characters but of course it shouldn't be taken as a newline when it is part
560        of another character. The bug was that, for an unlimited repeat of . in
561        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
562        characters when looking for a newline.
563    
564     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
565    
566     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
567        in debug output.
568    
569     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
570        long printing in the pcrecpp unittest when running under MinGW.
571    
572     6. ESC_K was left out of the EBCDIC table.
573    
574     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
575        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
576        limit also applies to "virtual nesting" when a pattern is recursive, and in
577        this case 1000 isn't so big. I have been able to remove this limit at the
578        expense of backing off one optimization in certain circumstances. Normally,
579        when pcre_exec() would call its internal match() function recursively and
580        immediately return the result unconditionally, it uses a "tail recursion"
581        feature to save stack. However, when a subpattern that can match an empty
582        string has an unlimited repetition quantifier, it no longer makes this
583        optimization. That gives it a stack frame in which to save the data for
584        checking that an empty string has been matched. Previously this was taken
585        from the 1000-entry workspace that had been reserved. So now there is no
586        explicit limit, but more stack is used.
587    
588     8. Applied Daniel's patches to solve problems with the import/export magic
589        syntax that is required for Windows, and which was going wrong for the
590        pcreposix and pcrecpp parts of the library. These were overlooked when this
591        problem was solved for the main library.
592    
593     9. There were some crude static tests to avoid integer overflow when computing
594        the size of patterns that contain repeated groups with explicit upper
595        limits. As the maximum quantifier is 65535, the maximum group length was
596        set at 30,000 so that the product of these two numbers did not overflow a
597        32-bit integer. However, it turns out that people want to use groups that
598        are longer than 30,000 bytes (though not repeat them that many times).
599        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
600        made it possible to implement the integer overflow checks in a much more
601        dynamic way, which I have now done. The artificial limitation on group
602        length has been removed - we now have only the limit on the total length of
603        the compiled pattern, which depends on the LINK_SIZE setting.
604    
605    10. Fixed a bug in the documentation for get/copy named substring when
606        duplicate names are permitted. If none of the named substrings are set, the
607        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
608        empty string.
609    
610    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
611        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
612        because the ] is interpreted as the first data character and the
613        terminating ] is not found. PCRE has been made compatible with Perl in this
614        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
615        cause memory overwriting.
616    
617    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
618        string has been matched (to stop an infinite loop). It was not recognizing
619        a conditional subpattern that could match an empty string if that
620        subpattern was within another subpattern. For example, it looped when
621        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
622        condition was not nested. This bug has been fixed.
623    
624    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
625        past the start of the subject in the presence of bytes with the top bit
626        set, for example "\x8aBCD".
627    
628    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
629        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
630    
631    14. Optimized (?!) to (*FAIL).
632    
633    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
634        This restricts code points to be within the range 0 to 0x10FFFF, excluding
635        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
636        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
637        does: it's just the validity check that is more restrictive.
638    
639    16. Inserted checks for integer overflows during escape sequence (backslash)
640        processing, and also fixed erroneous offset values for syntax errors during
641        backslash processing.
642    
643    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
644        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
645    
646    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
647        caused an overrun.
648    
649    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
650        something other than just ASCII characters) inside a group that had an
651        unlimited repeat caused a loop at compile time (while checking to see
652        whether the group could match an empty string).
653    
654    20. Debugging a pattern containing \p or \P could cause a crash. For example,
655        [\P{Any}] did so. (Error in the code for printing property names.)
656    
657    21. An orphan \E inside a character class could cause a crash.
658    
659    22. A repeated capturing bracket such as (A)? could cause a wild memory
660        reference during compilation.
661    
662    23. There are several functions in pcre_compile() that scan along a compiled
663        expression for various reasons (e.g. to see if it's fixed length for look
664        behind). There were bugs in these functions when a repeated \p or \P was
665        present in the pattern. These operators have additional parameters compared
666        with \d, etc, and these were not being taken into account when moving along
667        the compiled data. Specifically:
668    
669        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
670            length.
671    
672        (b) An item such as \pL+ within a repeated group could cause crashes or
673            loops.
674    
675        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
676            "reference to non-existent subpattern" error.
677    
678        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
679    
680    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
681        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
682    
683    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
684    
685    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
686        character were causing crashes (broken optimization).
687    
688    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
689        \p or \P) caused a compile-time loop.
690    
691    28. More problems have arisen in unanchored patterns when CRLF is a valid line
692        break. For example, the unstudied pattern [\r\n]A does not match the string
693        "\r\nA" because change 7.0/46 below moves the current point on by two
694        characters after failing to match at the start. However, the pattern \nA
695        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
696        the same is true. There doesn't seem any very clean way out of this, but
697        what I have chosen to do makes the common cases work: PCRE now takes note
698        of whether there can be an explicit match for \r or \n anywhere in the
699        pattern, and if so, 7.0/46 no longer applies. As part of this change,
700        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
701        pattern has explicit CR or LF references.
702    
703    29. Added (*CR) etc for changing newline setting at start of pattern.
704    
705    
706    Version 7.2 19-Jun-07
707    ---------------------
708    
709     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
710        which is apparently normally available under Windows.
711    
712     2. Re-jig the pcregrep tests with different newline settings in an attempt
713        to make them independent of the local environment's newline setting.
714    
715     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
716    
717     4. Some of the "internals" tests were previously cut out when the link size
718        was not 2, because the output contained actual offsets. The recent new
719        "Z" feature of pcretest means that these can be cut out, making the tests
720        usable with all link sizes.
721    
722     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
723        stack recursion. This gives a massive performance boost under BSD, but just
724        a small improvement under Linux. However, it saves one field in the frame
725        in all cases.
726    
727     6. Added more features from the forthcoming Perl 5.10:
728    
729        (a) (?-n) (where n is a string of digits) is a relative subroutine or
730            recursion call. It refers to the nth most recently opened parentheses.
731    
732        (b) (?+n) is also a relative subroutine call; it refers to the nth next
733            to be opened parentheses.
734    
735        (c) Conditions that refer to capturing parentheses can be specified
736            relatively, for example, (?(-2)... or (?(+3)...
737    
738        (d) \K resets the start of the current match so that everything before
739            is not part of it.
740    
741        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
742    
743        (f) \g{name} is another synonym - part of Perl 5.10's unification of
744            reference syntax.
745    
746        (g) (?| introduces a group in which the numbering of parentheses in each
747            alternative starts with the same number.
748    
749        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
750    
751     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
752        PCRE_INFO_JCHANGED.
753    
754     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
755        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
756        for detecting groups that can match an empty string.
757    
758     9. A pattern with a very large number of alternatives (more than several
759        hundred) was running out of internal workspace during the pre-compile
760        phase, where pcre_compile() figures out how much memory will be needed. A
761        bit of new cunning has reduced the workspace needed for groups with
762        alternatives. The 1000-alternative test pattern now uses 12 bytes of
763        workspace instead of running out of the 4096 that are available.
764    
765    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
766    
767    11. Applied patch from Google to remove an optimization that didn't quite work.
768        The report of the bug said:
769    
770          pcrecpp::RE("a*").FullMatch("aaa") matches, while
771          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
772          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
773    
774    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
775        it matched the wrong number of bytes.
776    
777    
778    Version 7.1 24-Apr-07
779    ---------------------
780    
781     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
782        that is more "standard", making use of automake and other Autotools. There
783        is some re-arrangement of the files and adjustment of comments consequent
784        on this.
785    
786     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
787        for recursive directory scanning broke on some systems because the files
788        are not scanned in any specific order and on different systems the order
789        was different. A call to "sort" has been inserted into RunGrepTest for the
790        approprate test as a short-term fix. In the longer term there may be an
791        alternative.
792    
793     3. I had an email from Eric Raymond about problems translating some of PCRE's
794        man pages to HTML (despite the fact that I distribute HTML pages, some
795        people do their own conversions for various reasons). The problems
796        concerned the use of low-level troff macros .br and .in. I have therefore
797        removed all such uses from the man pages (some were redundant, some could
798        be replaced by .nf/.fi pairs). The 132html script that I use to generate
799        HTML has been updated to handle .nf/.fi and to complain if it encounters
800        .br or .in.
801    
802     4. Updated comments in configure.ac that get placed in config.h.in and also
803        arranged for config.h to be included in the distribution, with the name
804        config.h.generic, for the benefit of those who have to compile without
805        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
806    
807     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
808        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
809        makevp.bat for the current PCRE, using the additional files
810        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
811    
812     6. A Windows user reported a minor discrepancy with test 2, which turned out
813        to be caused by a trailing space on an input line that had got lost in his
814        copy. The trailing space was an accident, so I've just removed it.
815    
816     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
817        that is needed.
818    
819     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
820        as "const" (a) because they are and (b) because it helps the PHP
821        maintainers who have recently made a script to detect big data structures
822        in the php code that should be moved to the .rodata section. I remembered
823        to update Builducptable as well, so it won't revert if ucptable.h is ever
824        re-created.
825    
826     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
827        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
828        order to be able to cut out the UTF-8 tables in the latter when UTF-8
829        support is not required. This saves 1.5-2K of code, which is important in
830        some applications.
831    
832        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
833        so as not to refer to the tables, even though these functions will never be
834        called when UTF-8 support is disabled. Otherwise there are problems with a
835        shared library.
836    
837    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
838    
839        (a) It was defining its arguments as char * instead of void *.
840    
841        (b) It was assuming that all moves were upwards in memory; this was true
842            a long time ago when I wrote it, but is no longer the case.
843    
844        The emulated memove() is provided for those environments that have neither
845        memmove() nor bcopy(). I didn't think anyone used it these days, but that
846        is clearly not the case, as these two bugs were recently reported.
847    
848    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
849        and Detrail to create the HTML documentation, the .txt form of the man
850        pages, and it removes trailing spaces from listed files. It also creates
851        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
852        case, it wraps all the #defines with #ifndefs. This script should be run
853        before "make dist".
854    
855    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
856        with Unicode property support.
857    
858        (a) For a maximizing quantifier, if the two different cases of the
859            character were of different lengths in their UTF-8 codings (there are
860            some cases like this - I found 11), and the matching function had to
861            back up over a mixture of the two cases, it incorrectly assumed they
862            were both the same length.
863    
864        (b) When PCRE was configured to use the heap rather than the stack for
865            recursion during matching, it was not correctly preserving the data for
866            the other case of a UTF-8 character when checking ahead for a match
867            while processing a minimizing repeat. If the check also involved
868            matching a wide character, but failed, corruption could cause an
869            erroneous result when trying to check for a repeat of the original
870            character.
871    
872    13. Some tidying changes to the testing mechanism:
873    
874        (a) The RunTest script now detects the internal link size and whether there
875            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
876            values substituted by "configure". (The RunGrepTest script already did
877            this for UTF-8.) The configure.ac script no longer substitutes the
878            relevant variables.
879    
880        (b) The debugging options /B and /D in pcretest show the compiled bytecode
881            with length and offset values. This means that the output is different
882            for different internal link sizes. Test 2 is skipped for link sizes
883            other than 2 because of this, bypassing the problem. Unfortunately,
884            there was also a test in test 3 (the locale tests) that used /B and
885            failed for link sizes other than 2. Rather than cut the whole test out,
886            I have added a new /Z option to pcretest that replaces the length and
887            offset values with spaces. This is now used to make test 3 independent
888            of link size. (Test 2 will be tidied up later.)
889    
890    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
891        segmentation fault instead of returning the appropriate error message.
892    
893    15. In multiline mode when the newline sequence was set to "any", the pattern
894        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
895        This doesn't seem right; it now treats the CRLF combination as the line
896        ending, and so does not match in that case. It's only a pattern such as ^$
897        that would hit this one: something like ^ABC$ would have failed after \r
898        and then tried again after \r\n.
899    
900    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
901        in an attempt to make files that differ only in their line terminators
902        compare equal. This works on Linux.
903    
904    17. Under certain error circumstances pcregrep might try to free random memory
905        as it exited. This is now fixed, thanks to valgrind.
906    
907    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
908        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
909        was because its rules for how to advance for /g after matching an empty
910        string at the end of a line did not allow for this case. They now check for
911        it specially.
912    
913    20. pcretest is supposed to handle patterns and data of any length, by
914        extending its buffers when necessary. It was getting this wrong when the
915        buffer for a data line had to be extended.
916    
917    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
918        CRLF as a newline sequence.
919    
920    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
921        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
922        I have nevertheless tidied it up.
923    
924    23. Added some casts to kill warnings from HP-UX ia64 compiler.
925    
926    24. Added a man page for pcre-config.
927    
928    
929    Version 7.0 19-Dec-06
930    ---------------------
931    
932     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
933        moving to gcc 4.1.1.
934    
935     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
936        sys/time.h, which is documented as needed for this function. It doesn't
937        seem to matter on Linux, but it showed up on some releases of OS X.
938    
939     3. It seems that there are systems where bytes whose values are greater than
940        127 match isprint() in the "C" locale. The "C" locale should be the
941        default when a C program starts up. In most systems, only ASCII printing
942        characters match isprint(). This difference caused the output from pcretest
943        to vary, making some of the tests fail. I have changed pcretest so that:
944    
945        (a) When it is outputting text in the compiled version of a pattern, bytes
946            other than 32-126 are always shown as hex escapes.
947    
948        (b) When it is outputting text that is a matched part of a subject string,
949            it does the same, unless a different locale has been set for the match
950            (using the /L modifier). In this case, it uses isprint() to decide.
951    
952     4. Fixed a major bug that caused incorrect computation of the amount of memory
953        required for a compiled pattern when options that changed within the
954        pattern affected the logic of the preliminary scan that determines the
955        length. The relevant options are -x, and -i in UTF-8 mode. The result was
956        that the computed length was too small. The symptoms of this bug were
957        either the PCRE error "internal error: code overflow" from pcre_compile(),
958        or a glibc crash with a message such as "pcretest: free(): invalid next
959        size (fast)". Examples of patterns that provoked this bug (shown in
960        pcretest format) are:
961    
962          /(?-x: )/x
963          /(?x)(?-x: \s*#\s*)/
964          /((?i)[\x{c0}])/8
965          /(?i:[\x{c0}])/8
966    
967        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
968        is now done differently.
969    
970     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
971        wrapper classes; (b) implement a new function in the C++ scanner that is
972        more efficient than the old way of doing things because it avoids levels of
973        recursion in the regex matching; (c) add a paragraph to the documentation
974        for the FullMatch() function.
975    
976     6. The escape sequence \n was being treated as whatever was defined as
977        "newline". Not only was this contrary to the documentation, which states
978        that \n is character 10 (hex 0A), but it also went horribly wrong when
979        "newline" was defined as CRLF. This has been fixed.
980    
981     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
982        was being set to -1 for the "end of line" case (supposedly a value that no
983        character can have). Though this value is never used (the check for end of
984        line is "zero bytes in current character"), it caused compiler complaints.
985        I've changed it to 0xffffffff.
986    
987     8. In pcre_version.c, the version string was being built by a sequence of
988        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
989        string (as it is for production releases) called a macro with an empty
990        argument. The C standard says the result of this is undefined. The gcc
991        compiler treats it as an empty string (which was what was wanted) but it is
992        reported that Visual C gives an error. The source has been hacked around to
993        avoid this problem.
994    
995     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
996        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
997        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
998        of them did).
999    
1000    10. Originally, pcretest opened its input and output without "b"; then I was
1001        told that "b" was needed in some environments, so it was added for release
1002        5.0 to both the input and output. (It makes no difference on Unix-like
1003        systems.) Later I was told that it is wrong for the input on Windows. I've
1004        now abstracted the modes into two macros, to make it easier to fiddle with
1005        them, and removed "b" from the input mode under Windows.
1006    
1007    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1008    
1009    12. Added -help and --help to pcretest as an official way of being reminded
1010        of the options.
1011    
1012    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1013        and pcrecpp.cc because they annoy compilers at high warning levels.
1014    
1015    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1016    
1017    15. Fixed an occurrence of == in configure.ac that should have been = (shell
1018        scripts are not C programs :-) and which was not noticed because it works
1019        on Linux.
1020    
1021    16. pcretest is supposed to handle any length of pattern and data line (as one
1022        line or as a continued sequence of lines) by extending its input buffer if
1023        necessary. This feature was broken for very long pattern lines, leading to
1024        a string of junk being passed to pcre_compile() if the pattern was longer
1025        than about 50K.
1026    
1027    17. I have done a major re-factoring of the way pcre_compile() computes the
1028        amount of memory needed for a compiled pattern. Previously, there was code
1029        that made a preliminary scan of the pattern in order to do this. That was
1030        OK when PCRE was new, but as the facilities have expanded, it has become
1031        harder and harder to keep it in step with the real compile phase, and there
1032        have been a number of bugs (see for example, 4 above). I have now found a
1033        cunning way of running the real compile function in a "fake" mode that
1034        enables it to compute how much memory it would need, while actually only
1035        ever using a few hundred bytes of working memory and without too many
1036        tests of the mode. This should make future maintenance and development
1037        easier. A side effect of this work is that the limit of 200 on the nesting
1038        depth of parentheses has been removed (though this was never a serious
1039        limitation, I suspect). However, there is a downside: pcre_compile() now
1040        runs more slowly than before (30% or more, depending on the pattern). I
1041        hope this isn't a big issue. There is no effect on runtime performance.
1042    
1043    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1044        newline (only possible for the last line of a file) and it was a
1045        pattern that set a locale (followed by /Lsomething), pcretest crashed.
1046    
1047    19. Added additional timing features to pcretest. (1) The -tm option now times
1048        matching only, not compiling. (2) Both -t and -tm can be followed, as a
1049        separate command line item, by a number that specifies the number of
1050        repeats to use when timing. The default is 50000; this gives better
1051        precision, but takes uncomfortably long for very large patterns.
1052    
1053    20. Extended pcre_study() to be more clever in cases where a branch of a
1054        subpattern has no definite first character. For example, (a*|b*)[cd] would
1055        previously give no result from pcre_study(). Now it recognizes that the
1056        first character must be a, b, c, or d.
1057    
1058    21. There was an incorrect error "recursive call could loop indefinitely" if
1059        a subpattern (or the entire pattern) that was being tested for matching an
1060        empty string contained only one non-empty item after a nested subpattern.
1061        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1062        incorrectly, because the \d was being skipped in the check.
1063    
1064    22. The pcretest program now has a new pattern option /B and a command line
1065        option -b, which is equivalent to adding /B to every pattern. This causes
1066        it to show the compiled bytecode, without the additional information that
1067        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1068        is the same as /B/I).
1069    
1070    23. A new optimization is now able automatically to treat some sequences such
1071        as a*b as a*+b. More specifically, if something simple (such as a character
1072        or a simple class like \d) has an unlimited quantifier, and is followed by
1073        something that cannot possibly match the quantified thing, the quantifier
1074        is automatically "possessified".
1075    
1076    24. A recursive reference to a subpattern whose number was greater than 39
1077        went wrong under certain circumstances in UTF-8 mode. This bug could also
1078        have affected the operation of pcre_study().
1079    
1080    25. Realized that a little bit of performance could be had by replacing
1081        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1082    
1083    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1084    
1085    27. Possessive quantifiers such as a++ were previously implemented by turning
1086        them into atomic groups such as ($>a+). Now they have their own opcodes,
1087        which improves performance. This includes the automatically created ones
1088        from 23 above.
1089    
1090    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1091        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1092        the first matched character to be a colon. This applied both to named and
1093        numbered groups.
1094    
1095    29. The ucpinternal.h header file was missing its idempotency #ifdef.
1096    
1097    30. I was sent a "project" file called libpcre.a.dev which I understand makes
1098        building PCRE on Windows easier, so I have included it in the distribution.
1099    
1100    31. There is now a check in pcretest against a ridiculously large number being
1101        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1102        loop, the loop is abandoned.
1103    
1104    32. Forward references to subpatterns in conditions such as (?(2)...) where
1105        subpattern 2 is defined later cause pcre_compile() to search forwards in
1106        the pattern for the relevant set of parentheses. This search went wrong
1107        when there were unescaped parentheses in a character class, parentheses
1108        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1109    
1110    33. "Subroutine" calls and backreferences were previously restricted to
1111        referencing subpatterns earlier in the regex. This restriction has now
1112        been removed.
1113    
1114    34. Added a number of extra features that are going to be in Perl 5.10. On the
1115        whole, these are just syntactic alternatives for features that PCRE had
1116        previously implemented using the Python syntax or my own invention. The
1117        other formats are all retained for compatibility.
1118    
1119        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1120            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1121            also .NET compatible.
1122    
1123        (b) A recursion or subroutine call to a named group can now be defined as
1124            (?&name) as well as (?P>name).
1125    
1126        (c) A backreference to a named group can now be defined as \k<name> or
1127            \k'name' as well as (?P=name). The new forms, as well as being in Perl
1128            5.10, are also .NET compatible.
1129    
1130        (d) A conditional reference to a named group can now use the syntax
1131            (?(<name>) or (?('name') as well as (?(name).
1132    
1133        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1134            groups (named and numbered) that are never evaluated inline, but can be
1135            called as "subroutines" from elsewhere. In effect, the DEFINE condition
1136            is always false. There may be only one alternative in such a group.
1137    
1138        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1139            as the simple (?(R). The condition is true only if the most recent
1140            recursion is that of the given number or name. It does not search out
1141            through the entire recursion stack.
1142    
1143        (g) The escape \gN or \g{N} has been added, where N is a positive or
1144            negative number, specifying an absolute or relative reference.
1145    
1146    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1147        some "unreachable code" warnings.
1148    
1149    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1150        things, this adds five new scripts.
1151    
1152    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1153        There were also incompatibilities regarding the handling of \Q..\E inside
1154        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1155        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1156    
1157    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1158        matches an empty string, and forcibly breaks the loop. There were bugs in
1159        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1160        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1161        separate and independent bugs (that affected different cases) have been
1162        fixed.
1163    
1164    39. Refactored the code to abolish the use of different opcodes for small
1165        capturing bracket numbers. This is a tidy that I avoided doing when I
1166        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1167        The new approach is not only tidier, it makes it possible to reduce the
1168        memory needed to fix the previous bug (38).
1169    
1170    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1171        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1172        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1173        mode.
1174    
1175    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1176        report.
1177    
1178    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1179        copy construction and assignment in the C++ wrapper.
1180    
1181    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1182        couple of bugs that could have given wrong results in the "--newline=crlf"
1183        case.
1184    
1185    44. Added a number of casts and did some reorganization of signed/unsigned int
1186        variables following suggestions from Dair Grant. Also renamed the variable
1187        "this" as "item" because it is a C++ keyword.
1188    
1189    45. Arranged for dftables to add
1190    
1191          #include "pcre_internal.h"
1192    
1193        to pcre_chartables.c because without it, gcc 4.x may remove the array
1194        definition from the final binary if PCRE is built into a static library and
1195        dead code stripping is activated.
1196    
1197    46. For an unanchored pattern, if a match attempt fails at the start of a
1198        newline sequence, and the newline setting is CRLF or ANY, and the next two
1199        characters are CRLF, advance by two characters instead of one.
1200    
1201    
1202    Version 6.7 04-Jul-06
1203    ---------------------
1204    
1205     1. In order to handle tests when input lines are enormously long, pcretest has
1206        been re-factored so that it automatically extends its buffers when
1207        necessary. The code is crude, but this _is_ just a test program. The
1208        default size has been increased from 32K to 50K.
1209    
1210     2. The code in pcre_study() was using the value of the re argument before
1211        testing it for NULL. (Of course, in any sensible call of the function, it
1212        won't be NULL.)
1213    
1214     3. The memmove() emulation function in pcre_internal.h, which is used on
1215        systems that lack both memmove() and bcopy() - that is, hardly ever -
1216        was missing a "static" storage class specifier.
1217    
1218     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1219        containing an extended class (one that cannot be represented by a bitmap
1220        because it contains high-valued characters or Unicode property items, e.g.
1221        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1222        pattern, but PCRE should not loop if you do not (it no longer does).
1223        [Detail: two cases were found: (a) a repeated subpattern containing an
1224        extended class; (b) a recursive reference to a subpattern that followed a
1225        previous extended class. It wasn't skipping over the extended class
1226        correctly when UTF-8 mode was not set.]
1227    
1228     5. A negated single-character class was not being recognized as fixed-length
1229        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1230        compile error "lookbehind assertion is not fixed length".
1231    
1232     6. The RunPerlTest auxiliary script was showing an unexpected difference
1233        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1234        write a Perl script that can interpret lines of an input file either as
1235        byte characters or as UTF-8, which is what "perltest" was being required to
1236        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1237        can't do is switch easily at run time between having the "use utf8;" pragma
1238        or not. In the end, I fudged it by using the RunPerlTest script to insert
1239        "use utf8;" explicitly for the UTF-8 tests.
1240    
1241     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1242        the end of the subject string, contrary to the documentation and to what
1243        Perl does. This was true of both matching functions. Now it matches only at
1244        the start of the subject and immediately after *internal* newlines.
1245    
1246     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1247        a pointer to an int instead of a pointer to an unsigned long int. This
1248        caused problems on 64-bit systems.
1249    
1250     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1251        instance of the 'standard' template library not being so standard".
1252    
1253    10. There was no check on the number of named subpatterns nor the maximum
1254        length of a subpattern name. The product of these values is used to compute
1255        the size of the memory block for a compiled pattern. By supplying a very
1256        long subpattern name and a large number of named subpatterns, the size
1257        computation could be caused to overflow. This is now prevented by limiting
1258        the length of names to 32 characters, and the number of named subpatterns
1259        to 10,000.
1260    
1261    11. Subpatterns that are repeated with specific counts have to be replicated in
1262        the compiled pattern. The size of memory for this was computed from the
1263        length of the subpattern and the repeat count. The latter is limited to
1264        65535, but there was no limit on the former, meaning that integer overflow
1265        could in principle occur. The compiled length of a repeated subpattern is
1266        now limited to 30,000 bytes in order to prevent this.
1267    
1268    12. Added the optional facility to have named substrings with the same name.
1269    
1270    13. Added the ability to use a named substring as a condition, using the
1271        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1272        are numbers (not recommended). Forward references are permitted.
1273    
1274    14. Added forward references in named backreferences (if you see what I mean).
1275    
1276    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1277        pattern could run off the end of the subject. For example, the pattern
1278        "(?s)(.{1,5})"8 did this with the subject "ab".
1279    
1280    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1281        PCRE_CASELESS was set when matching characters that were quantified with ?
1282        or *.
1283    
1284    17. A character class other than a single negated character that had a minimum
1285        but no maximum quantifier - for example [ab]{6,} - was not handled
1286        correctly by pce_dfa_exec(). It would match only one character.
1287    
1288    18. A valid (though odd) pattern that looked like a POSIX character
1289        class but used an invalid character after [ (for example [[,abc,]]) caused
1290        pcre_compile() to give the error "Failed: internal error: code overflow" or
1291        in some cases to crash with a glibc free() error. This could even happen if
1292        the pattern terminated after [[ but there just happened to be a sequence of
1293        letters, a binary zero, and a closing ] in the memory that followed.
1294    
1295    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1296        over the years. Originally (before any Unicode support), just the bottom 8
1297        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1298        output from "man perlunicode" includes this:
1299    
1300          The regular expression compiler produces polymorphic opcodes.  That
1301          is, the pattern adapts to the data and automatically switches to
1302          the Unicode character scheme when presented with Unicode data--or
1303          instead uses a traditional byte scheme when presented with byte
1304          data.
1305    
1306        Sadly, a wide octal escape does not cause a switch, and in a string with
1307        no other multibyte characters, these octal escapes are treated as before.
1308        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1309        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1310        Unicode string.
1311    
1312        I have not perpetrated such confusion in PCRE. Up till now, it took just
1313        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1314        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1315        translate to the appropriate multibyte character.
1316    
1317    29. Applied some refactoring to reduce the number of warnings from Microsoft
1318        and Borland compilers. This has included removing the fudge introduced
1319        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1320        a warning about an unused variable.
1321    
1322    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1323        characters since release 4.0, because Perl (from release 5.004) does not.
1324        [Or at least, is documented not to: some releases seem to be in conflict
1325        with the documentation.] However, when a pattern was studied with
1326        pcre_study() and all its branches started with \s, PCRE still included VT
1327        as a possible starting character. Of course, this did no harm; it just
1328        caused an unnecessary match attempt.
1329    
1330    22. Removed a now-redundant internal flag bit that recorded the fact that case
1331        dependency changed within the pattern. This was once needed for "required
1332        byte" processing, but is no longer used. This recovers a now-scarce options
1333        bit. Also moved the least significant internal flag bit to the most-
1334        significant bit of the word, which was not previously used (hangover from
1335        the days when it was an int rather than a uint) to free up another bit for
1336        the future.
1337    
1338    23. Added support for CRLF line endings as well as CR and LF. As well as the
1339        default being selectable at build time, it can now be changed at runtime
1340        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1341        specify that it is scanning data with non-default line endings.
1342    
1343    24. Changed the definition of CXXLINK to make it agree with the definition of
1344        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1345    
1346    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1347        recursions. This makes a big different to stack usage for some patterns.
1348    
1349    26. If a subpattern containing a named recursion or subroutine reference such
1350        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1351        the space required for the compiled pattern went wrong and gave too small a
1352        value. Depending on the environment, this could lead to "Failed: internal
1353        error: code overflow at offset 49" or "glibc detected double free or
1354        corruption" errors.
1355    
1356    27. Applied patches from Google (a) to support the new newline modes and (b) to
1357        advance over multibyte UTF-8 characters in GlobalReplace.
1358    
1359    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1360        difference for some implementation of PCRE in some Windows version.
1361    
1362    29. Added some extra testing facilities to pcretest:
1363    
1364        \q<number>   in a data line sets the "match limit" value
1365        \Q<number>   in a data line sets the "match recursion limt" value
1366        -S <number>  sets the stack size, where <number> is in megabytes
1367    
1368        The -S option isn't available for Windows.
1369    
1370    
1371    Version 6.6 06-Feb-06
1372    ---------------------
1373    
1374     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1375        in pcreposix.h. I have copied the definition from pcre.h.
1376    
1377     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1378        because pcre.h is no longer a built file.
1379    
1380     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1381        not normally included in the compiled code.
1382    
1383    
1384  Version 6.5 01-Feb-06  Version 6.5 01-Feb-06
1385  ---------------------  ---------------------
1386    

Legend:
Removed from v.87  
changed lines
  Added in v.402

  ViewVC Help
Powered by ViewVC 1.1.5