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

Diff of /code/trunk/ChangeLog

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

revision 507 by ph10, Wed Mar 10 16:08:01 2010 UTC revision 978 by ph10, Sun Jun 17 16:55:07 2012 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 10-Mar-2010  Version 8.31 02-June-2012
5    -------------------------
6    
7    1.  Fixing a wrong JIT test case and some compiler warnings.
8    
9    2.  Removed a bashism from the RunTest script.
10    
11    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
12        to unsigned type, result still unsigned" that was given by an MS compiler
13        on encountering the code "-sizeof(xxx)".
14    
15    4.  Partial matching support is added to the JIT compiler.
16    
17    5.  Fixed several bugs concerned with partial matching of items that consist
18        of more than one character:
19    
20        (a) /^(..)\1/ did not partially match "aba" because checking references was
21            done on an "all or nothing" basis. This also applied to repeated
22            references.
23    
24        (b) \R did not give a hard partial match if \r was found at the end of the
25            subject.
26    
27        (c) \X did not give a hard partial match after matching one or more
28            characters at the end of the subject.
29    
30        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
31            a partial match for the string "\r".
32    
33        (e) When newline was set to CRLF, the metacharacter "." did not recognize
34            a partial match for a CR character at the end of the subject string.
35    
36    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
37        running pcretest, the text "(JIT)" added to the output whenever JIT is
38        actually used to run the match.
39    
40    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
41        or /S+[+] with a digit between 1 and 7.
42    
43    8.  OP_NOT now supports any UTF character not just single-byte ones.
44    
45    9.  (*MARK) control verb is now supported by the JIT compiler.
46    
47    10. The command "./RunTest list" lists the available tests without actually
48        running any of them. (Because I keep forgetting what they all are.)
49    
50    11. Add PCRE_INFO_MAXLOOKBEHIND.
51    
52    12. Applied a (slightly modified) user-supplied patch that improves performance
53        when the heap is used for recursion (compiled with --disable-stack-for-
54        recursion). Instead of malloc and free for each heap frame each time a
55        logical recursion happens, frames are retained on a chain and re-used where
56        possible. This sometimes gives as much as 30% improvement.
57    
58    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
59        call.
60    
61    14. As documented, (*COMMIT) is now confined to within a positive assertion.
62    
63    15. It is now possible to link pcretest with libedit as an alternative to
64        libreadline.
65    
66    16. (*COMMIT) control verb is now supported by the JIT compiler.
67    
68    17. The Unicode data tables have been updated to Unicode 6.1.0.
69    
70    18. Added --file-list option to pcregrep.
71    
72    19. Added binary file support to pcregrep, including the -a, --binary-files,
73        -I, and --text options.
74    
75    20. The madvise function is renamed for posix_madvise for QNX compatibility
76        reasons. Fixed by Giuseppe D'Angelo.
77    
78    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
79    
80    22. Changed the option for creating symbolic links for 16-bit man pages from
81        -s to -sf so that re-installing does not cause issues.
82    
83    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
84    
85    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
86        matches in certain environments (the workspace was not being correctly
87        retained). Also added to pcre_dfa_exec() a simple plausibility check on
88        some of the workspace data at the beginning of a restart.
89    
90    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
91        was not doing so when it should - probably a typo introduced by SVN 528
92        (change 8.10/14).
93    
94    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
95        \w+ when the character tables indicated that \x{c4} was a word character.
96        There were several related cases, all because the tests for doing a table
97        lookup were testing for characters less than 127 instead of 255.
98    
99    27. If a pattern contains capturing parentheses that are not used in a match,
100        their slots in the ovector are set to -1. For those that are higher than
101        any matched groups, this happens at the end of processing. In the case when
102        there were back references that the ovector was too small to contain
103        (causing temporary malloc'd memory to be used during matching), and the
104        highest capturing number was not used, memory off the end of the ovector
105        was incorrectly being set to -1. (It was using the size of the temporary
106        memory instead of the true size.)
107    
108    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
109        ovector size, it uses memory at the end of the block that it has got.
110    
111    29. Check for an overlong MARK name and give an error at compile time. The
112        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
113    
114    30. JIT compiler update.
115    
116    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
117        Rill for the patch.
118    
119    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
120    
121    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
122    
123    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
124        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
125        was enabled.
126    
127    35. Improve JIT code generation for greedy plus quantifier.
128    
129    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
130        1 to "aa" instead of to an empty string. The bug affected repeated groups
131        that could potentially match an empty string.
132    
133    37. Optimizing single character iterators in JIT.
134    
135    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
136        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
137        codepoints that are too big for the mode are faulted, and in a UTF mode,
138        disallowed codepoints are also faulted.
139    
140    
141    Version 8.30 04-February-2012
142    -----------------------------
143    
144    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
145        name is defined in ctype.h.
146    
147    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
148        only in quite long subpatterns.
149    
150    3.  Removed the function pcre_info(), which has been obsolete and deprecated
151        since it was replaced by pcre_fullinfo() in February 2000.
152    
153    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
154        match a (*MARK), and the match failed at the start of the subject, a
155        reference to memory before the start of the subject could occur. This bug
156        was introduced by fix 17 of release 8.21.
157    
158    5.  A reference to an unset group with zero minimum repetition was giving
159        totally wrong answers (in non-JavaScript-compatibility mode). For example,
160        /(another)?(\1?)test/ matched against "hello world test". This bug was
161        introduced in release 8.13.
162    
163    6.  Add support for 16-bit character strings (a large amount of work involving
164        many changes and refactorings).
165    
166    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
167        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
168        from a file.
169    
170    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
171        rounding is not applied in this particular case).
172    
173    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
174        if they appear, or are escaped, in patterns.
175    
176    10. Get rid of a number of -Wunused-but-set-variable warnings.
177    
178    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
179        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
180        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
181        also returns the mark "x". This bug applied to capturing parentheses,
182        non-capturing parentheses, and atomic parentheses. It also applied to some
183        assertions.
184    
185    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
186        information out of configure.ac instead of relying on pcre.h.generic, which
187        is not stored in the repository.
188    
189    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
190        -lreadline.
191    
192    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
193    
194    15. Applied Graycode's patch to put the top-level frame on the stack rather
195        than the heap when not using the stack for recursion. This gives a
196        performance improvement in many cases when recursion is not deep.
197    
198    16. Experimental code added to "pcretest -C" to output the stack frame size.
199    
200    
201    Version 8.21 12-Dec-2011
202    ------------------------
203    
204    1.  Updating the JIT compiler.
205    
206    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
207        are added as well.
208    
209    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
210        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
211        calling _pcre_jit_exec. Some extra comments are added.
212    
213    4.  (*MARK) settings inside atomic groups that do not contain any capturing
214        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
215        was introduced by change 18 for 8.20.
216    
217    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
218        ECMA-262 standard.
219    
220    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
221        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
222        This bug was probably introduced by change 9 of 8.13.
223    
224    7.  While fixing 6 above, I noticed that a number of other items were being
225        incorrectly rejected as "not fixed length". This arose partly because newer
226        opcodes had not been added to the fixed-length checking code. I have (a)
227        corrected the bug and added tests for these items, and (b) arranged for an
228        error to occur if an unknown opcode is encountered while checking for fixed
229        length instead of just assuming "not fixed length". The items that were
230        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
231        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
232        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
233    
234    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
235        being incorrectly compiled and would have given unpredicatble results.
236    
237    9.  A possessively repeated subpattern with minimum repeat count greater than
238        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
239        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
240        the first (A) could occur when it should not.
241    
242    10. Add a cast and remove a redundant test from the code.
243    
244    11. JIT should use pcre_malloc/pcre_free for allocation.
245    
246    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
247        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
248        is anything other than /usr, -L is still shown).
249    
250    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
251    
252    14. Perl does not support \N without a following name in a [] class; PCRE now
253        also gives an error.
254    
255    15. If a forward reference was repeated with an upper limit of around 2000,
256        it caused the error "internal error: overran compiling workspace". The
257        maximum number of forward references (including repeats) was limited by the
258        internal workspace, and dependent on the LINK_SIZE. The code has been
259        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
260        the default depends on LINK_SIZE. There is a new upper limit (for safety)
261        of around 200,000 forward references. While doing this, I also speeded up
262        the filling in of repeated forward references.
263    
264    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
265        incorrectly expecting the subject to contain another "a" after the start.
266    
267    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
268        in the match, the SKIP should be ignored. This was not happening; instead
269        the SKIP was being treated as NOMATCH. For patterns such as
270        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
271        tested.
272    
273    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
274        now much more compatible with Perl, in particular in cases where the result
275        is a non-match for a non-anchored pattern. For example, if
276        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
277        "m", where previously it did not return a name. A side effect of this
278        change is that for partial matches, the last encountered mark name is
279        returned, as for non matches. A number of tests that were previously not
280        Perl-compatible have been moved into the Perl-compatible test files. The
281        refactoring has had the pleasing side effect of removing one argument from
282        the match() function, thus reducing its stack requirements.
283    
284    19. If the /S+ option was used in pcretest to study a pattern using JIT,
285        subsequent uses of /S (without +) incorrectly behaved like /S+.
286    
287    21. Retrieve executable code size support for the JIT compiler and fixing
288        some warnings.
289    
290    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
291        not work when the shorter character appeared right at the end of the
292        subject string.
293    
294    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
295        systems.
296    
297    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
298        output it when the /M option is used in pcretest.
299    
300    25. The CheckMan script was not being included in the distribution. Also, added
301        an explicit "perl" to run Perl scripts from the PrepareRelease script
302        because this is reportedly needed in Windows.
303    
304    26. If study data was being save in a file and studying had not found a set of
305        "starts with" bytes for the pattern, the data written to the file (though
306        never used) was taken from uninitialized memory and so caused valgrind to
307        complain.
308    
309    27. Updated RunTest.bat as provided by Sheri Pierce.
310    
311    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
312    
313    29. Computation of memory usage for the table of capturing group names was
314        giving an unnecessarily large value.
315    
316    
317    Version 8.20 21-Oct-2011
318    ------------------------
319    
320    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
321        a POSIX class. After further experiments with Perl, which convinced me that
322        Perl has bugs and confusions, a closing square bracket is no longer allowed
323        in a POSIX name. This bug also affected patterns with classes that started
324        with full stops.
325    
326    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
327        captured substring, but while checking the failing first alternative,
328        substring 1 is temporarily captured. If the output vector supplied to
329        pcre_exec() was not big enough for this capture, the yield of the function
330        was still zero ("insufficient space for captured substrings"). This cannot
331        be totally fixed without adding another stack variable, which seems a lot
332        of expense for a edge case. However, I have improved the situation in cases
333        such as /(a)(b)x|abc/ matched against "abc", where the return code
334        indicates that fewer than the maximum number of slots in the ovector have
335        been set.
336    
337    3.  Related to (2) above: when there are more back references in a pattern than
338        slots in the output vector, pcre_exec() uses temporary memory during
339        matching, and copies in the captures as far as possible afterwards. It was
340        using the entire output vector, but this conflicts with the specification
341        that only 2/3 is used for passing back captured substrings. Now it uses
342        only the first 2/3, for compatibility. This is, of course, another edge
343        case.
344    
345    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
346        main code base, and can be used by building with --enable-jit. When this is
347        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
348        runtime --no-jit option is given.
349    
350    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
351        ovector, the return from the function was zero, implying that there were
352        other matches that did not fit. The correct "exactly full" value is now
353        returned.
354    
355    6.  If a subpattern that was called recursively or as a subroutine contained
356        (*PRUNE) or any other control that caused it to give a non-standard return,
357        invalid errors such as "Error -26 (nested recursion at the same subject
358        position)" or even infinite loops could occur.
359    
360    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
361        computing the minimum length on reaching *ACCEPT, and so ended up with the
362        wrong value of 1 rather than 0. Further investigation indicates that
363        computing a minimum subject length in the presence of *ACCEPT is difficult
364        (think back references, subroutine calls), and so I have changed the code
365        so that no minimum is registered for a pattern that contains *ACCEPT.
366    
367    8.  If (*THEN) was present in the first (true) branch of a conditional group,
368        it was not handled as intended. [But see 16 below.]
369    
370    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
371        Sheri Pierce.
372    
373    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
374        the first byte in a match must be "a".
375    
376    11. Change 17 for 8.13 increased the recursion depth for patterns like
377        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
378        pattern contains any instances of (*THEN). If it does not, the old
379        optimizations are restored. It would be nice to do this on a per-group
380        basis, but at the moment that is not feasible.
381    
382    12. In some environments, the output of pcretest -C is CRLF terminated. This
383        broke RunTest's code that checks for the link size. A single white space
384        character after the value is now allowed for.
385    
386    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
387        For "fr", it uses the Windows-specific input and output files.
388    
389    14. If (*THEN) appeared in a group that was called recursively or as a
390        subroutine, it did not work as intended. [But see next item.]
391    
392    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
393        pattern fragments (but not containing any | characters). If A and B are
394        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
395        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
396        D. In other words, Perl considers parentheses that do not contain any |
397        characters to be part of a surrounding alternative, whereas PCRE was
398        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
399        differently. PCRE now behaves in the same way as Perl, except in the case
400        of subroutine/recursion calls such as (?1) which have in any case always
401        been different (but PCRE had them first :-).
402    
403    16. Related to 15 above: Perl does not treat the | in a conditional group as
404        creating alternatives. Such a group is treated in the same way as an
405        ordinary group without any | characters when processing (*THEN). PCRE has
406        been changed to match Perl's behaviour.
407    
408    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
409        RunGrepTest script failed.
410    
411    18. Change 22 for version 13 caused atomic groups to use more stack. This is
412        inevitable for groups that contain captures, but it can lead to a lot of
413        stack use in large patterns. The old behaviour has been restored for atomic
414        groups that do not contain any capturing parentheses.
415    
416    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
417        suppress the check for a minimum subject length at run time. (If it was
418        given to pcre_exec() or pcre_dfa_exec() it did work.)
419    
420    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
421        fail to work when decoding hex characters in data strings in EBCDIC
422        environments.
423    
424    21. It appears that in at least one Mac OS environment, the isxdigit() function
425        is implemented as a macro that evaluates to its argument more than once,
426        contravening the C 90 Standard (I haven't checked a later standard). There
427        was an instance in pcretest which caused it to go wrong when processing
428        \x{...} escapes in subject strings. The has been rewritten to avoid using
429        things like p++ in the argument of isxdigit().
430    
431    
432    Version 8.13 16-Aug-2011
433    ------------------------
434    
435    1.  The Unicode data tables have been updated to Unicode 6.0.0.
436    
437    2.  Two minor typos in pcre_internal.h have been fixed.
438    
439    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
440        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
441        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
442    
443    4.  There were a number of related bugs in the code for matching backrefences
444        caselessly in UTF-8 mode when codes for the characters concerned were
445        different numbers of bytes. For example, U+023A and U+2C65 are an upper
446        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
447        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
448        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
449        2-byte code at the end of the subject (it thought there wasn't enough data
450        left).
451    
452    5.  Comprehensive information about what went wrong is now returned by
453        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
454        as the output vector has at least 2 elements. The offset of the start of
455        the failing character and a reason code are placed in the vector.
456    
457    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
458        now returned is for the first byte of the failing character, instead of the
459        last byte inspected. This is an incompatible change, but I hope it is small
460        enough not to be a problem. It makes the returned offset consistent with
461        pcre_exec() and pcre_dfa_exec().
462    
463    7.  pcretest now gives a text phrase as well as the error number when
464        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
465        failure, the offset and reason code are output.
466    
467    8.  When \R was used with a maximizing quantifier it failed to skip backwards
468        over a \r\n pair if the subsequent match failed. Instead, it just skipped
469        back over a single character (\n). This seems wrong (because it treated the
470        two characters as a single entity when going forwards), conflicts with the
471        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
472        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
473        has been changed.
474    
475    9.  Some internal refactoring has changed the processing so that the handling
476        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
477        time (the PCRE_DOTALL option was changed this way some time ago: version
478        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
479        which was always a bit of a fudge. It also means that there is one less
480        argument for the match() function, which reduces its stack requirements
481        slightly. This change also fixes an incompatibility with Perl: the pattern
482        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
483    
484    10. More internal refactoring has drastically reduced the number of recursive
485        calls to match() for possessively repeated groups such as (abc)++ when
486        using pcre_exec().
487    
488    11. While implementing 10, a number of bugs in the handling of groups were
489        discovered and fixed:
490    
491        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
492        (a|)*(?1) gave a compile-time internal error.
493        ((a|)+)+  did not notice that the outer group could match an empty string.
494        (^a|^)+   was not marked as anchored.
495        (.*a|.*)+ was not marked as matching at start or after a newline.
496    
497    12. Yet more internal refactoring has removed another argument from the match()
498        function. Special calls to this function are now indicated by setting a
499        value in a variable in the "match data" data block.
500    
501    13. Be more explicit in pcre_study() instead of relying on "default" for
502        opcodes that mean there is no starting character; this means that when new
503        ones are added and accidentally left out of pcre_study(), testing should
504        pick them up.
505    
506    14. The -s option of pcretest has been documented for ages as being an old
507        synonym of -m (show memory usage). I have changed it to mean "force study
508        for every regex", that is, assume /S for every regex. This is similar to -i
509        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
510        using it. It makes it easier to run collections of tests with and without
511        study enabled, and thereby test pcre_study() more easily. All the standard
512        tests are now run with and without -s (but some patterns can be marked as
513        "never study" - see 20 below).
514    
515    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
516        restoration of the capturing data to the outer values was not happening
517        correctly.
518    
519    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
520        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
521        pattern had matched an empty string, and so incorrectly returned a no
522        match.
523    
524    17. There was optimizing code for the last branch of non-capturing parentheses,
525        and also for the obeyed branch of a conditional subexpression, which used
526        tail recursion to cut down on stack usage. Unfortunately, now that there is
527        the possibility of (*THEN) occurring in these branches, tail recursion is
528        no longer possible because the return has to be checked for (*THEN). These
529        two optimizations have therefore been removed. [But see 8.20/11 above.]
530    
531    18. If a pattern containing \R was studied, it was assumed that \R always
532        matched two bytes, thus causing the minimum subject length to be
533        incorrectly computed because \R can also match just one byte.
534    
535    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
536        was incorrectly computed.
537    
538    20. If /S is present twice on a test pattern in pcretest input, it now
539        *disables* studying, thereby overriding the use of -s on the command line
540        (see 14 above). This is necessary for one or two tests to keep the output
541        identical in both cases.
542    
543    21. When (*ACCEPT) was used in an assertion that matched an empty string and
544        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
545    
546    22. When an atomic group that contained a capturing parenthesis was
547        successfully matched, but the branch in which it appeared failed, the
548        capturing was not being forgotten if a higher numbered group was later
549        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
550        group 1 to "a", when in fact it should be unset. This applied to multi-
551        branched capturing and non-capturing groups, repeated or not, and also to
552        positive assertions (capturing in negative assertions does not happen
553        in PCRE) and also to nested atomic groups.
554    
555    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
556        subject after a captured substring, to make it easier to tell which of a
557        number of identical substrings has been captured.
558    
559    24. The way atomic groups are processed by pcre_exec() has been changed so that
560        if they are repeated, backtracking one repetition now resets captured
561        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
562        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
563        "aaa". Previously, it would have been "a". As part of this code
564        refactoring, the way recursive calls are handled has also been changed.
565    
566    25. If an assertion condition captured any substrings, they were not passed
567        back unless some other capturing happened later. For example, if
568        (?(?=(a))a) was matched against "a", no capturing was returned.
569    
570    26. When studying a pattern that contained subroutine calls or assertions,
571        the code for finding the minimum length of a possible match was handling
572        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
573        group 1 called group 2 while simultaneously a separate group 2 called group
574        1). A stack overflow occurred in this case. I have fixed this by limiting
575        the recursion depth to 10.
576    
577    27. Updated RunTest.bat in the distribution to the version supplied by Tom
578        Fortmann. This supports explicit test numbers on the command line, and has
579        argument validation and error reporting.
580    
581    28. An instance of \X with an unlimited repeat could fail if at any point the
582        first character it looked at was a mark character.
583    
584    29. Some minor code refactoring concerning Unicode properties and scripts
585        should reduce the stack requirement of match() slightly.
586    
587    30. Added the '=' option to pcretest to check the setting of unused capturing
588        slots at the end of the pattern, which are documented as being -1, but are
589        not included in the return count.
590    
591    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
592        compiled something random. Now it gives a compile-time error (as does
593        Perl).
594    
595    32. A *MARK encountered during the processing of a positive assertion is now
596        recorded and passed back (compatible with Perl).
597    
598    33. If --only-matching or --colour was set on a pcregrep call whose pattern
599        had alternative anchored branches, the search for a second match in a line
600        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
601        matched the line "0102" twice. The same bug affected patterns that started
602        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
603        twice.
604    
605    34. Previously, PCRE did not allow quantification of assertions. However, Perl
606        does, and because of capturing effects, quantifying parenthesized
607        assertions may at times be useful. Quantifiers are now allowed for
608        parenthesized assertions.
609    
610    35. A minor code tidy in pcre_compile() when checking options for \R usage.
611    
612    36. \g was being checked for fancy things in a character class, when it should
613        just be a literal "g".
614    
615    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
616        appearance of a nested POSIX class supersedes an apparent external class.
617        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
618        unescaped square brackets may also appear as part of class names. For
619        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
620        more like Perl. (But see 8.20/1 above.)
621    
622    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
623        was because it thought it was \N{name}, which is not supported).
624    
625    39. Add minix to OS list not supporting the -S option in pcretest.
626    
627    40. PCRE tries to detect cases of infinite recursion at compile time, but it
628        cannot analyze patterns in sufficient detail to catch mutual recursions
629        such as ((?1))((?2)). There is now a runtime test that gives an error if a
630        subgroup is called recursively as a subpattern for a second time at the
631        same position in the subject string. In previous releases this might have
632        been caught by the recursion limit, or it might have run out of stack.
633    
634    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
635        happen only once. PCRE was, however incorrectly giving a compile time error
636        "recursive call could loop indefinitely" because it cannot analyze the
637        pattern in sufficient detail. The compile time test no longer happens when
638        PCRE is compiling a conditional subpattern, but actual runaway loops are
639        now caught at runtime (see 40 above).
640    
641    42. It seems that Perl allows any characters other than a closing parenthesis
642        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
643        has been changed to be the same.
644    
645    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
646        as not to get warnings when autogen.sh is called. Also changed
647        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
648    
649    44. To help people who use pcregrep to scan files containing exceedingly long
650        lines, the following changes have been made:
651    
652        (a) The default value of the buffer size parameter has been increased from
653            8K to 20K. (The actual buffer used is three times this size.)
654    
655        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
656            PCRE is built.
657    
658        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
659            to be set at run time.
660    
661        (d) Numerical values in pcregrep options can be followed by K or M, for
662            example --buffer-size=50K.
663    
664        (e) If a line being scanned overflows pcregrep's buffer, an error is now
665            given and the return code is set to 2.
666    
667    45. Add a pointer to the latest mark to the callout data block.
668    
669    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
670        partial match of an empty string instead of no match. This was specific to
671        the use of ".".
672    
673    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
674        complete match instead of a partial match. This bug was dependent on both
675        the PCRE_UTF8 and PCRE_DOTALL options being set.
676    
677    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
678        starting byte set, because \b was not being ignored.
679    
680    
681    Version 8.12 15-Jan-2011
682    ------------------------
683    
684    1.  Fixed some typos in the markup of the man pages, and wrote a script that
685        checks for such things as part of the documentation building process.
686    
687    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
688        --match-limit and --recursion-limit options (added for 8.11). In
689        particular, this made one of the standard tests fail. (The integer value
690        went into the wrong half of a long int.)
691    
692    3.  If the --colour option was given to pcregrep with -v (invert match), it
693        did strange things, either producing crazy output, or crashing. It should,
694        of course, ignore a request for colour when reporting lines that do not
695        match.
696    
697    4.  Another pcregrep bug caused similar problems if --colour was specified with
698        -M (multiline) and the pattern match finished with a line ending.
699    
700    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
701        matched in multiline mode, the following line was shown as part of the
702        match. This seems wrong, so I have changed it.
703    
704    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
705        the check for further matches in the same line (so they could be coloured)
706        to overrun the end of the current line. If another match was found, it was
707        incorrectly shown (and then shown again when found in the next line).
708    
709    7.  If pcregrep was compiled under Windows, there was a reference to the
710        function pcregrep_exit() before it was defined. I am assuming this was
711        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
712        reported by a user. I've moved the definition above the reference.
713    
714    
715    Version 8.11 10-Dec-2010
716    ------------------------
717    
718    1.  (*THEN) was not working properly if there were untried alternatives prior
719        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
720        backtracked to try for "b" instead of moving to the next alternative branch
721        at the same level (in this case, to look for "c"). The Perl documentation
722        is clear that when (*THEN) is backtracked onto, it goes to the "next
723        alternative in the innermost enclosing group".
724    
725    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
726        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
727        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
728        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
729        (*THEN).
730    
731    3.  If \s appeared in a character class, it removed the VT character from
732        the class, even if it had been included by some previous item, for example
733        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
734        of \s, but is part of the POSIX "space" class.)
735    
736    4.  A partial match never returns an empty string (because you can always
737        match an empty string at the end of the subject); however the checking for
738        an empty string was starting at the "start of match" point. This has been
739        changed to the "earliest inspected character" point, because the returned
740        data for a partial match starts at this character. This means that, for
741        example, /(?<=abc)def/ gives a partial match for the subject "abc"
742        (previously it gave "no match").
743    
744    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
745        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
746        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
747        has an implication that the given string is incomplete (because a partial
748        match is preferred over a full match). For this reason, these items now
749        give a partial match in this situation. [Aside: previously, the one case
750        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
751        match rather than a full match, which was wrong by the old rules, but is
752        now correct.]
753    
754    6.  There was a bug in the handling of #-introduced comments, recognized when
755        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
756        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
757        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
758        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
759        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
760        places in pcre_compile().
761    
762    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
763        comments when looking ahead for named forward references to subpatterns,
764        the only newline sequence it recognized was NL. It now handles newlines
765        according to the set newline convention.
766    
767    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
768        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
769        cater for a lack of strerror(). These oversights have been fixed.
770    
771    9.  Added --match-limit and --recursion-limit to pcregrep.
772    
773    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
774    
775    11. When the -o option was used, pcregrep was setting a return code of 1, even
776        when matches were found, and --line-buffered was not being honoured.
777    
778    12. Added an optional parentheses number to the -o and --only-matching options
779        of pcregrep.
780    
781    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
782        can match an empty string. The code to do it in pcretest and pcredemo
783        needed fixing:
784    
785        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
786            only one byte after an empty string match just before CRLF (this case
787            just got forgotten; "any" and "anycrlf" were OK).
788    
789        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
790            mode when an empty string match preceded an ASCII character followed by
791            a non-ASCII character. (The code for advancing by one character rather
792            than one byte was nonsense.)
793    
794        (c) The pcredemo.c sample program did not have any code at all to handle
795            the cases when CRLF is a valid newline sequence.
796    
797    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
798        as a starting offset was within the subject string. There is now a new
799        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
800        negative or greater than the length of the string. In order to test this,
801        pcretest is extended to allow the setting of negative starting offsets.
802    
803    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
804        starting offset points to the beginning of a UTF-8 character was
805        unnecessarily clumsy. I tidied it up.
806    
807    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
808        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
809    
810    17. Nobody had reported that the --include_dir option, which was added in
811        release 7.7 should have been called --include-dir (hyphen, not underscore)
812        for compatibility with GNU grep. I have changed it to --include-dir, but
813        left --include_dir as an undocumented synonym, and the same for
814        --exclude-dir, though that is not available in GNU grep, at least as of
815        release 2.5.4.
816    
817    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
818        characters from a string of bytes) have been redefined so as not to use
819        loops, in order to improve performance in some environments. At the same
820        time, I abstracted some of the common code into auxiliary macros to save
821        repetition (this should not affect the compiled code).
822    
823    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
824        compile-time error is now given if \c is not followed by an ASCII
825        character, that is, a byte less than 128. (In EBCDIC mode, the code is
826        different, and any byte value is allowed.)
827    
828    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
829        START_OPTIMIZE option, which is now allowed at compile time - but just
830        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
831        to pcregrep and other applications that have no direct access to PCRE
832        options. The new /Y option in pcretest sets this option when calling
833        pcre_compile().
834    
835    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
836        back references. Groups containing recursive back references were forced to
837        be atomic by that change, but in the case of named groups, the amount of
838        memory required was incorrectly computed, leading to "Failed: internal
839        error: code overflow". This has been fixed.
840    
841    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
842        pcretest.c, to avoid build problems in some Borland environments.
843    
844    
845    Version 8.10 25-Jun-2010
846    ------------------------
847    
848    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
849        THEN.
850    
851    2.  (*ACCEPT) was not working when inside an atomic group.
852    
853    3.  Inside a character class, \B is treated as a literal by default, but
854        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
855        causes the error). The code is unchanged, but I tidied the documentation.
856    
857    4.  Inside a character class, PCRE always treated \R and \X as literals,
858        whereas Perl faults them if its -w option is set. I have changed PCRE so
859        that it faults them when PCRE_EXTRA is set.
860    
861    5.  Added support for \N, which always matches any character other than
862        newline. (It is the same as "." when PCRE_DOTALL is not set.)
863    
864    6.  When compiling pcregrep with newer versions of gcc which may have
865        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
866        declared with attribute warn_unused_result" were given. Just casting the
867        result to (void) does not stop the warnings; a more elaborate fudge is
868        needed. I've used a macro to implement this.
869    
870    7.  Minor change to pcretest.c to avoid a compiler warning.
871    
872    8.  Added four artifical Unicode properties to help with an option to make
873        \s etc use properties (see next item). The new properties are: Xan
874        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
875    
876    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
877        use Unicode properties. (*UCP) at the start of a pattern can be used to set
878        this option. Modified pcretest to add /W to test this facility. Added
879        REG_UCP to make it available via the POSIX interface.
880    
881    10. Added --line-buffered to pcregrep.
882    
883    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
884        studied, and the match started with a letter with a code point greater than
885        127 whose first byte was different to the first byte of the other case of
886        the letter, the other case of this starting letter was not recognized
887        (#976).
888    
889    12. If a pattern that was studied started with a repeated Unicode property
890        test, for example, \p{Nd}+, there was the theoretical possibility of
891        setting up an incorrect bitmap of starting bytes, but fortunately it could
892        not have actually happened in practice until change 8 above was made (it
893        added property types that matched character-matching opcodes).
894    
895    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
896        possible starting bytes for non-anchored patterns.
897    
898    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
899        \R, and also a number of cases that involve Unicode properties, both
900        explicit and implicit when PCRE_UCP is set.
901    
902    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
903        input, it could crash or give wrong results if characters with values
904        greater than 0xc0 were present in the subject string. (Detail: it assumed
905        UTF-8 input when processing these items.)
906    
907    16. Added a lot of (int) casts to avoid compiler warnings in systems where
908        size_t is 64-bit (#991).
909    
910    17. Added a check for running out of memory when PCRE is compiled with
911        --disable-stack-for-recursion (#990).
912    
913    18. If the last data line in a file for pcretest does not have a newline on
914        the end, a newline was missing in the output.
915    
916    19. The default pcre_chartables.c file recognizes only ASCII characters (values
917        less than 128) in its various bitmaps. However, there is a facility for
918        generating tables according to the current locale when PCRE is compiled. It
919        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
920        characters, are recognized by isspace() and therefore were getting set in
921        these tables, and indeed these tables seem to approximate to ISO 8859. This
922        caused a problem in UTF-8 mode when pcre_study() was used to create a list
923        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
924        which of course cannot start UTF-8 characters. I have changed the code so
925        that only real ASCII characters (less than 128) and the correct starting
926        bytes for UTF-8 encodings are set for characters greater than 127 when in
927        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
928        altogether.)
929    
930    20. Added the /T option to pcretest so as to be able to run tests with non-
931        standard character tables, thus making it possible to include the tests
932        used for 19 above in the standard set of tests.
933    
934    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
935        reference to a subpattern the other side of a comment that contains an
936        opening parenthesis caused either an internal compiling error, or a
937        reference to the wrong subpattern.
938    
939    
940    Version 8.02 19-Mar-2010
941  ------------------------  ------------------------
942    
943  1.  The Unicode data tables have been updated to Unicode 5.2.0.  1.  The Unicode data tables have been updated to Unicode 5.2.0.

Legend:
Removed from v.507  
changed lines
  Added in v.978

  ViewVC Help
Powered by ViewVC 1.1.5