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

Diff of /code/trunk/ChangeLog

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

revision 496 by ph10, Tue Mar 2 19:11:17 2010 UTC revision 773 by ph10, Wed Nov 30 18:10:27 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.02 01-Mar-2010  Version 8.21
5    ------------
6    
7    1.  Updating the JIT compiler.
8    
9    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
10        are added as well.
11    
12    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
13        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
14        calling _pcre_jit_exec. Some extra comments are added.
15    
16    4.  Mark settings inside atomic groups that do not contain any capturing
17        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
18        was introduced by change 18 for 8.20.
19    
20    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
21        ECMA-262 standard.
22    
23    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
24        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
25        This bug was probably introduced by change 9 of 8.13.
26    
27    7.  While fixing 6 above, I noticed that a number of other items were being
28        incorrectly rejected as "not fixed length". This arose partly because newer
29        opcodes had not been added to the fixed-length checking code. I have (a)
30        corrected the bug and added tests for these items, and (b) arranged for an
31        error to occur if an unknown opcode is encountered while checking for fixed
32        length instead of just assuming "not fixed length". The items that were
33        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
34        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
35        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
36    
37    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
38        being incorrectly compiled and would have given unpredicatble results.
39    
40    9.  A possessively repeated subpattern with minimum repeat count greater than
41        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
42        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
43        the first (A) could occur when it should not.
44    
45    10. Add a cast and remove a redundant test from the code.
46    
47    11. JIT should use pcre_malloc/pcre_free for allocation.
48    
49    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
50        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
51        is anything other than /usr, -L is still shown).
52    
53    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
54    
55    14. Perl does not support \N without a following name in a [] class; PCRE now
56        also gives an error.
57    
58    15. If a forward reference was repeated with an upper limit of around 2000,
59        it caused the error "internal error: overran compiling workspace". The
60        maximum number of forward references (including repeats) was limited by the
61        internal workspace, and dependent on the LINK_SIZE. The code has been
62        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
63        the default depends on LINK_SIZE. There is a new upper limit (for safety)
64        of around 200,000 forward references. While doing this, I also speeded up
65        the filling in of repeated forward references.
66    
67    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
68        incorrectly expecting the subject to contain another "a" after the start.
69    
70    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
71        in the match, the SKIP should be ignored. This was not happening; instead
72        the SKIP was being treated as NOMATCH. For patterns such as
73        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
74        tested.
75    
76    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
77        now much more compatible with Perl, in particular in cases where the result
78        is a non-match for a non-anchored pattern. For example, if
79        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
80        "m", where previously it did not return a name. A side effect of this
81        change is that for partial matches, the last encountered mark name is
82        returned, as for non matches. A number of tests that were previously not
83        Perl-compatible have been moved into the Perl-compatible test files. The
84        refactoring has had the pleasing side effect of removing one argument from
85        the match() function, thus reducing its stack requirements.
86    
87    
88    Version 8.20 21-Oct-2011
89    ------------------------
90    
91    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
92        a POSIX class. After further experiments with Perl, which convinced me that
93        Perl has bugs and confusions, a closing square bracket is no longer allowed
94        in a POSIX name. This bug also affected patterns with classes that started
95        with full stops.
96    
97    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
98        captured substring, but while checking the failing first alternative,
99        substring 1 is temporarily captured. If the output vector supplied to
100        pcre_exec() was not big enough for this capture, the yield of the function
101        was still zero ("insufficient space for captured substrings"). This cannot
102        be totally fixed without adding another stack variable, which seems a lot
103        of expense for a edge case. However, I have improved the situation in cases
104        such as /(a)(b)x|abc/ matched against "abc", where the return code
105        indicates that fewer than the maximum number of slots in the ovector have
106        been set.
107    
108    3.  Related to (2) above: when there are more back references in a pattern than
109        slots in the output vector, pcre_exec() uses temporary memory during
110        matching, and copies in the captures as far as possible afterwards. It was
111        using the entire output vector, but this conflicts with the specification
112        that only 2/3 is used for passing back captured substrings. Now it uses
113        only the first 2/3, for compatibility. This is, of course, another edge
114        case.
115    
116    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
117        main code base, and can be used by building with --enable-jit. When this is
118        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
119        runtime --no-jit option is given.
120    
121    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
122        ovector, the return from the function was zero, implying that there were
123        other matches that did not fit. The correct "exactly full" value is now
124        returned.
125    
126    6.  If a subpattern that was called recursively or as a subroutine contained
127        (*PRUNE) or any other control that caused it to give a non-standard return,
128        invalid errors such as "Error -26 (nested recursion at the same subject
129        position)" or even infinite loops could occur.
130    
131    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
132        computing the minimum length on reaching *ACCEPT, and so ended up with the
133        wrong value of 1 rather than 0. Further investigation indicates that
134        computing a minimum subject length in the presence of *ACCEPT is difficult
135        (think back references, subroutine calls), and so I have changed the code
136        so that no minimum is registered for a pattern that contains *ACCEPT.
137    
138    8.  If (*THEN) was present in the first (true) branch of a conditional group,
139        it was not handled as intended. [But see 16 below.]
140    
141    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
142        Sheri Pierce.
143    
144    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
145        the first byte in a match must be "a".
146    
147    11. Change 17 for 8.13 increased the recursion depth for patterns like
148        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
149        pattern contains any instances of (*THEN). If it does not, the old
150        optimizations are restored. It would be nice to do this on a per-group
151        basis, but at the moment that is not feasible.
152    
153    12. In some environments, the output of pcretest -C is CRLF terminated. This
154        broke RunTest's code that checks for the link size. A single white space
155        character after the value is now allowed for.
156    
157    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
158        For "fr", it uses the Windows-specific input and output files.
159    
160    14. If (*THEN) appeared in a group that was called recursively or as a
161        subroutine, it did not work as intended. [But see next item.]
162    
163    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
164        pattern fragments (but not containing any | characters). If A and B are
165        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
166        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
167        D. In other words, Perl considers parentheses that do not contain any |
168        characters to be part of a surrounding alternative, whereas PCRE was
169        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
170        differently. PCRE now behaves in the same way as Perl, except in the case
171        of subroutine/recursion calls such as (?1) which have in any case always
172        been different (but PCRE had them first :-).
173    
174    16. Related to 15 above: Perl does not treat the | in a conditional group as
175        creating alternatives. Such a group is treated in the same way as an
176        ordinary group without any | characters when processing (*THEN). PCRE has
177        been changed to match Perl's behaviour.
178    
179    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
180        RunGrepTest script failed.
181    
182    18. Change 22 for version 13 caused atomic groups to use more stack. This is
183        inevitable for groups that contain captures, but it can lead to a lot of
184        stack use in large patterns. The old behaviour has been restored for atomic
185        groups that do not contain any capturing parentheses.
186    
187    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
188        suppress the check for a minimum subject length at run time. (If it was
189        given to pcre_exec() or pcre_dfa_exec() it did work.)
190    
191    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
192        fail to work when decoding hex characters in data strings in EBCDIC
193        environments.
194    
195    21. It appears that in at least one Mac OS environment, the isxdigit() function
196        is implemented as a macro that evaluates to its argument more than once,
197        contravening the C 90 Standard (I haven't checked a later standard). There
198        was an instance in pcretest which caused it to go wrong when processing
199        \x{...} escapes in subject strings. The has been rewritten to avoid using
200        things like p++ in the argument of isxdigit().
201    
202    
203    Version 8.13 16-Aug-2011
204    ------------------------
205    
206    1.  The Unicode data tables have been updated to Unicode 6.0.0.
207    
208    2.  Two minor typos in pcre_internal.h have been fixed.
209    
210    3.  Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
211        pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
212        in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
213    
214    4.  There were a number of related bugs in the code for matching backrefences
215        caselessly in UTF-8 mode when codes for the characters concerned were
216        different numbers of bytes. For example, U+023A and U+2C65 are an upper
217        and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
218        (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
219        code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
220        2-byte code at the end of the subject (it thought there wasn't enough data
221        left).
222    
223    5.  Comprehensive information about what went wrong is now returned by
224        pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
225        as the output vector has at least 2 elements. The offset of the start of
226        the failing character and a reason code are placed in the vector.
227    
228    6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
229        now returned is for the first byte of the failing character, instead of the
230        last byte inspected. This is an incompatible change, but I hope it is small
231        enough not to be a problem. It makes the returned offset consistent with
232        pcre_exec() and pcre_dfa_exec().
233    
234    7.  pcretest now gives a text phrase as well as the error number when
235        pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
236        failure, the offset and reason code are output.
237    
238    8.  When \R was used with a maximizing quantifier it failed to skip backwards
239        over a \r\n pair if the subsequent match failed. Instead, it just skipped
240        back over a single character (\n). This seems wrong (because it treated the
241        two characters as a single entity when going forwards), conflicts with the
242        documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
243        behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
244        has been changed.
245    
246    9.  Some internal refactoring has changed the processing so that the handling
247        of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
248        time (the PCRE_DOTALL option was changed this way some time ago: version
249        7.7 change 16). This has made it possible to abolish the OP_OPT op code,
250        which was always a bit of a fudge. It also means that there is one less
251        argument for the match() function, which reduces its stack requirements
252        slightly. This change also fixes an incompatibility with Perl: the pattern
253        (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
254    
255    10. More internal refactoring has drastically reduced the number of recursive
256        calls to match() for possessively repeated groups such as (abc)++ when
257        using pcre_exec().
258    
259    11. While implementing 10, a number of bugs in the handling of groups were
260        discovered and fixed:
261    
262        (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
263        (a|)*(?1) gave a compile-time internal error.
264        ((a|)+)+  did not notice that the outer group could match an empty string.
265        (^a|^)+   was not marked as anchored.
266        (.*a|.*)+ was not marked as matching at start or after a newline.
267    
268    12. Yet more internal refactoring has removed another argument from the match()
269        function. Special calls to this function are now indicated by setting a
270        value in a variable in the "match data" data block.
271    
272    13. Be more explicit in pcre_study() instead of relying on "default" for
273        opcodes that mean there is no starting character; this means that when new
274        ones are added and accidentally left out of pcre_study(), testing should
275        pick them up.
276    
277    14. The -s option of pcretest has been documented for ages as being an old
278        synonym of -m (show memory usage). I have changed it to mean "force study
279        for every regex", that is, assume /S for every regex. This is similar to -i
280        and -d etc. It's slightly incompatible, but I'm hoping nobody is still
281        using it. It makes it easier to run collections of tests with and without
282        study enabled, and thereby test pcre_study() more easily. All the standard
283        tests are now run with and without -s (but some patterns can be marked as
284        "never study" - see 20 below).
285    
286    15. When (*ACCEPT) was used in a subpattern that was called recursively, the
287        restoration of the capturing data to the outer values was not happening
288        correctly.
289    
290    16. If a recursively called subpattern ended with (*ACCEPT) and matched an
291        empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
292        pattern had matched an empty string, and so incorrectly returned a no
293        match.
294    
295    17. There was optimizing code for the last branch of non-capturing parentheses,
296        and also for the obeyed branch of a conditional subexpression, which used
297        tail recursion to cut down on stack usage. Unfortunately, now that there is
298        the possibility of (*THEN) occurring in these branches, tail recursion is
299        no longer possible because the return has to be checked for (*THEN). These
300        two optimizations have therefore been removed. [But see 8.20/11 above.]
301    
302    18. If a pattern containing \R was studied, it was assumed that \R always
303        matched two bytes, thus causing the minimum subject length to be
304        incorrectly computed because \R can also match just one byte.
305    
306    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
307        was incorrectly computed.
308    
309    20. If /S is present twice on a test pattern in pcretest input, it now
310        *disables* studying, thereby overriding the use of -s on the command line
311        (see 14 above). This is necessary for one or two tests to keep the output
312        identical in both cases.
313    
314    21. When (*ACCEPT) was used in an assertion that matched an empty string and
315        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
316    
317    22. When an atomic group that contained a capturing parenthesis was
318        successfully matched, but the branch in which it appeared failed, the
319        capturing was not being forgotten if a higher numbered group was later
320        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
321        group 1 to "a", when in fact it should be unset. This applied to multi-
322        branched capturing and non-capturing groups, repeated or not, and also to
323        positive assertions (capturing in negative assertions does not happen
324        in PCRE) and also to nested atomic groups.
325    
326    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
327        subject after a captured substring, to make it easier to tell which of a
328        number of identical substrings has been captured.
329    
330    24. The way atomic groups are processed by pcre_exec() has been changed so that
331        if they are repeated, backtracking one repetition now resets captured
332        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
333        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
334        "aaa". Previously, it would have been "a". As part of this code
335        refactoring, the way recursive calls are handled has also been changed.
336    
337    25. If an assertion condition captured any substrings, they were not passed
338        back unless some other capturing happened later. For example, if
339        (?(?=(a))a) was matched against "a", no capturing was returned.
340    
341    26. When studying a pattern that contained subroutine calls or assertions,
342        the code for finding the minimum length of a possible match was handling
343        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
344        group 1 called group 2 while simultaneously a separate group 2 called group
345        1). A stack overflow occurred in this case. I have fixed this by limiting
346        the recursion depth to 10.
347    
348    27. Updated RunTest.bat in the distribution to the version supplied by Tom
349        Fortmann. This supports explicit test numbers on the command line, and has
350        argument validation and error reporting.
351    
352    28. An instance of \X with an unlimited repeat could fail if at any point the
353        first character it looked at was a mark character.
354    
355    29. Some minor code refactoring concerning Unicode properties and scripts
356        should reduce the stack requirement of match() slightly.
357    
358    30. Added the '=' option to pcretest to check the setting of unused capturing
359        slots at the end of the pattern, which are documented as being -1, but are
360        not included in the return count.
361    
362    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
363        compiled something random. Now it gives a compile-time error (as does
364        Perl).
365    
366    32. A *MARK encountered during the processing of a positive assertion is now
367        recorded and passed back (compatible with Perl).
368    
369    33. If --only-matching or --colour was set on a pcregrep call whose pattern
370        had alternative anchored branches, the search for a second match in a line
371        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
372        matched the line "0102" twice. The same bug affected patterns that started
373        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
374        twice.
375    
376    34. Previously, PCRE did not allow quantification of assertions. However, Perl
377        does, and because of capturing effects, quantifying parenthesized
378        assertions may at times be useful. Quantifiers are now allowed for
379        parenthesized assertions.
380    
381    35. A minor code tidy in pcre_compile() when checking options for \R usage.
382    
383    36. \g was being checked for fancy things in a character class, when it should
384        just be a literal "g".
385    
386    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
387        appearance of a nested POSIX class supersedes an apparent external class.
388        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
389        unescaped square brackets may also appear as part of class names. For
390        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
391        more like Perl. (But see 8.20/1 above.)
392    
393    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
394        was because it thought it was \N{name}, which is not supported).
395    
396    39. Add minix to OS list not supporting the -S option in pcretest.
397    
398    40. PCRE tries to detect cases of infinite recursion at compile time, but it
399        cannot analyze patterns in sufficient detail to catch mutual recursions
400        such as ((?1))((?2)). There is now a runtime test that gives an error if a
401        subgroup is called recursively as a subpattern for a second time at the
402        same position in the subject string. In previous releases this might have
403        been caught by the recursion limit, or it might have run out of stack.
404    
405    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
406        happen only once. PCRE was, however incorrectly giving a compile time error
407        "recursive call could loop indefinitely" because it cannot analyze the
408        pattern in sufficient detail. The compile time test no longer happens when
409        PCRE is compiling a conditional subpattern, but actual runaway loops are
410        now caught at runtime (see 40 above).
411    
412    42. It seems that Perl allows any characters other than a closing parenthesis
413        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
414        has been changed to be the same.
415    
416    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
417        as not to get warnings when autogen.sh is called. Also changed
418        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
419    
420    44. To help people who use pcregrep to scan files containing exceedingly long
421        lines, the following changes have been made:
422    
423        (a) The default value of the buffer size parameter has been increased from
424            8K to 20K. (The actual buffer used is three times this size.)
425    
426        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
427            PCRE is built.
428    
429        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
430            to be set at run time.
431    
432        (d) Numerical values in pcregrep options can be followed by K or M, for
433            example --buffer-size=50K.
434    
435        (e) If a line being scanned overflows pcregrep's buffer, an error is now
436            given and the return code is set to 2.
437    
438    45. Add a pointer to the latest mark to the callout data block.
439    
440    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
441        partial match of an empty string instead of no match. This was specific to
442        the use of ".".
443    
444    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
445        complete match instead of a partial match. This bug was dependent on both
446        the PCRE_UTF8 and PCRE_DOTALL options being set.
447    
448    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
449        starting byte set, because \b was not being ignored.
450    
451    
452    Version 8.12 15-Jan-2011
453    ------------------------
454    
455    1.  Fixed some typos in the markup of the man pages, and wrote a script that
456        checks for such things as part of the documentation building process.
457    
458    2.  On a big-endian 64-bit system, pcregrep did not correctly process the
459        --match-limit and --recursion-limit options (added for 8.11). In
460        particular, this made one of the standard tests fail. (The integer value
461        went into the wrong half of a long int.)
462    
463    3.  If the --colour option was given to pcregrep with -v (invert match), it
464        did strange things, either producing crazy output, or crashing. It should,
465        of course, ignore a request for colour when reporting lines that do not
466        match.
467    
468    4.  Another pcregrep bug caused similar problems if --colour was specified with
469        -M (multiline) and the pattern match finished with a line ending.
470    
471    5.  In pcregrep, when a pattern that ended with a literal newline sequence was
472        matched in multiline mode, the following line was shown as part of the
473        match. This seems wrong, so I have changed it.
474    
475    6.  Another pcregrep bug in multiline mode, when --colour was specified, caused
476        the check for further matches in the same line (so they could be coloured)
477        to overrun the end of the current line. If another match was found, it was
478        incorrectly shown (and then shown again when found in the next line).
479    
480    7.  If pcregrep was compiled under Windows, there was a reference to the
481        function pcregrep_exit() before it was defined. I am assuming this was
482        the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
483        reported by a user. I've moved the definition above the reference.
484    
485    
486    Version 8.11 10-Dec-2010
487    ------------------------
488    
489    1.  (*THEN) was not working properly if there were untried alternatives prior
490        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
491        backtracked to try for "b" instead of moving to the next alternative branch
492        at the same level (in this case, to look for "c"). The Perl documentation
493        is clear that when (*THEN) is backtracked onto, it goes to the "next
494        alternative in the innermost enclosing group".
495    
496    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
497        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
498        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
499        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
500        (*THEN).
501    
502    3.  If \s appeared in a character class, it removed the VT character from
503        the class, even if it had been included by some previous item, for example
504        in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
505        of \s, but is part of the POSIX "space" class.)
506    
507    4.  A partial match never returns an empty string (because you can always
508        match an empty string at the end of the subject); however the checking for
509        an empty string was starting at the "start of match" point. This has been
510        changed to the "earliest inspected character" point, because the returned
511        data for a partial match starts at this character. This means that, for
512        example, /(?<=abc)def/ gives a partial match for the subject "abc"
513        (previously it gave "no match").
514    
515    5.  Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
516        of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
517        previously a full match would be given. However, setting PCRE_PARTIAL_HARD
518        has an implication that the given string is incomplete (because a partial
519        match is preferred over a full match). For this reason, these items now
520        give a partial match in this situation. [Aside: previously, the one case
521        /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
522        match rather than a full match, which was wrong by the old rules, but is
523        now correct.]
524    
525    6.  There was a bug in the handling of #-introduced comments, recognized when
526        PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
527        If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
528        UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
529        scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
530        but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
531        places in pcre_compile().
532    
533    7.  Related to (6) above, when pcre_compile() was skipping #-introduced
534        comments when looking ahead for named forward references to subpatterns,
535        the only newline sequence it recognized was NL. It now handles newlines
536        according to the set newline convention.
537    
538    8.  SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
539        former, but used strtoul(), whereas pcretest avoided strtoul() but did not
540        cater for a lack of strerror(). These oversights have been fixed.
541    
542    9.  Added --match-limit and --recursion-limit to pcregrep.
543    
544    10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
545    
546    11. When the -o option was used, pcregrep was setting a return code of 1, even
547        when matches were found, and --line-buffered was not being honoured.
548    
549    12. Added an optional parentheses number to the -o and --only-matching options
550        of pcregrep.
551    
552    13. Imitating Perl's /g action for multiple matches is tricky when the pattern
553        can match an empty string. The code to do it in pcretest and pcredemo
554        needed fixing:
555    
556        (a) When the newline convention was "crlf", pcretest got it wrong, skipping
557            only one byte after an empty string match just before CRLF (this case
558            just got forgotten; "any" and "anycrlf" were OK).
559    
560        (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
561            mode when an empty string match preceded an ASCII character followed by
562            a non-ASCII character. (The code for advancing by one character rather
563            than one byte was nonsense.)
564    
565        (c) The pcredemo.c sample program did not have any code at all to handle
566            the cases when CRLF is a valid newline sequence.
567    
568    14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
569        as a starting offset was within the subject string. There is now a new
570        error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
571        negative or greater than the length of the string. In order to test this,
572        pcretest is extended to allow the setting of negative starting offsets.
573    
574    15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
575        starting offset points to the beginning of a UTF-8 character was
576        unnecessarily clumsy. I tidied it up.
577    
578    16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
579        bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
580    
581    17. Nobody had reported that the --include_dir option, which was added in
582        release 7.7 should have been called --include-dir (hyphen, not underscore)
583        for compatibility with GNU grep. I have changed it to --include-dir, but
584        left --include_dir as an undocumented synonym, and the same for
585        --exclude-dir, though that is not available in GNU grep, at least as of
586        release 2.5.4.
587    
588    18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
589        characters from a string of bytes) have been redefined so as not to use
590        loops, in order to improve performance in some environments. At the same
591        time, I abstracted some of the common code into auxiliary macros to save
592        repetition (this should not affect the compiled code).
593    
594    19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
595        compile-time error is now given if \c is not followed by an ASCII
596        character, that is, a byte less than 128. (In EBCDIC mode, the code is
597        different, and any byte value is allowed.)
598    
599    20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
600        START_OPTIMIZE option, which is now allowed at compile time - but just
601        passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
602        to pcregrep and other applications that have no direct access to PCRE
603        options. The new /Y option in pcretest sets this option when calling
604        pcre_compile().
605    
606    21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
607        back references. Groups containing recursive back references were forced to
608        be atomic by that change, but in the case of named groups, the amount of
609        memory required was incorrectly computed, leading to "Failed: internal
610        error: code overflow". This has been fixed.
611    
612    22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
613        pcretest.c, to avoid build problems in some Borland environments.
614    
615    
616    Version 8.10 25-Jun-2010
617    ------------------------
618    
619    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
620        THEN.
621    
622    2.  (*ACCEPT) was not working when inside an atomic group.
623    
624    3.  Inside a character class, \B is treated as a literal by default, but
625        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
626        causes the error). The code is unchanged, but I tidied the documentation.
627    
628    4.  Inside a character class, PCRE always treated \R and \X as literals,
629        whereas Perl faults them if its -w option is set. I have changed PCRE so
630        that it faults them when PCRE_EXTRA is set.
631    
632    5.  Added support for \N, which always matches any character other than
633        newline. (It is the same as "." when PCRE_DOTALL is not set.)
634    
635    6.  When compiling pcregrep with newer versions of gcc which may have
636        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
637        declared with attribute warn_unused_result" were given. Just casting the
638        result to (void) does not stop the warnings; a more elaborate fudge is
639        needed. I've used a macro to implement this.
640    
641    7.  Minor change to pcretest.c to avoid a compiler warning.
642    
643    8.  Added four artifical Unicode properties to help with an option to make
644        \s etc use properties (see next item). The new properties are: Xan
645        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
646    
647    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
648        use Unicode properties. (*UCP) at the start of a pattern can be used to set
649        this option. Modified pcretest to add /W to test this facility. Added
650        REG_UCP to make it available via the POSIX interface.
651    
652    10. Added --line-buffered to pcregrep.
653    
654    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
655        studied, and the match started with a letter with a code point greater than
656        127 whose first byte was different to the first byte of the other case of
657        the letter, the other case of this starting letter was not recognized
658        (#976).
659    
660    12. If a pattern that was studied started with a repeated Unicode property
661        test, for example, \p{Nd}+, there was the theoretical possibility of
662        setting up an incorrect bitmap of starting bytes, but fortunately it could
663        not have actually happened in practice until change 8 above was made (it
664        added property types that matched character-matching opcodes).
665    
666    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
667        possible starting bytes for non-anchored patterns.
668    
669    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
670        \R, and also a number of cases that involve Unicode properties, both
671        explicit and implicit when PCRE_UCP is set.
672    
673    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
674        input, it could crash or give wrong results if characters with values
675        greater than 0xc0 were present in the subject string. (Detail: it assumed
676        UTF-8 input when processing these items.)
677    
678    16. Added a lot of (int) casts to avoid compiler warnings in systems where
679        size_t is 64-bit (#991).
680    
681    17. Added a check for running out of memory when PCRE is compiled with
682        --disable-stack-for-recursion (#990).
683    
684    18. If the last data line in a file for pcretest does not have a newline on
685        the end, a newline was missing in the output.
686    
687    19. The default pcre_chartables.c file recognizes only ASCII characters (values
688        less than 128) in its various bitmaps. However, there is a facility for
689        generating tables according to the current locale when PCRE is compiled. It
690        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
691        characters, are recognized by isspace() and therefore were getting set in
692        these tables, and indeed these tables seem to approximate to ISO 8859. This
693        caused a problem in UTF-8 mode when pcre_study() was used to create a list
694        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
695        which of course cannot start UTF-8 characters. I have changed the code so
696        that only real ASCII characters (less than 128) and the correct starting
697        bytes for UTF-8 encodings are set for characters greater than 127 when in
698        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
699        altogether.)
700    
701    20. Added the /T option to pcretest so as to be able to run tests with non-
702        standard character tables, thus making it possible to include the tests
703        used for 19 above in the standard set of tests.
704    
705    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
706        reference to a subpattern the other side of a comment that contains an
707        opening parenthesis caused either an internal compiling error, or a
708        reference to the wrong subpattern.
709    
710    
711    Version 8.02 19-Mar-2010
712  ------------------------  ------------------------
713    
714  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.
715    
716  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
717      configured.      configured.
718    
719  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the  3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
720      original author of that file, following a query about its status.      original author of that file, following a query about its status.
721    
722  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include  4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
723      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.      inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
724    
725  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive  5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
726      quantifier applied to a forward-referencing subroutine call, could compile      quantifier applied to a forward-referencing subroutine call, could compile
727      incorrect code or give the error "internal error: previously-checked      incorrect code or give the error "internal error: previously-checked
728      referenced subpattern not found".      referenced subpattern not found".
729    
730    6.  Both MS Visual Studio and Symbian OS have problems with initializing
731        variables to point to external functions. For these systems, therefore,
732        pcre_malloc etc. are now initialized to local functions that call the
733        relevant global functions.
734    
735    7.  There were two entries missing in the vectors called coptable and poptable
736        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
737        I've fixed the data, and added a kludgy way of testing at compile time that
738        the lengths are correct (equal to the number of opcodes).
739    
740    8.  Following on from 7, I added a similar kludge to check the length of the
741        eint vector in pcreposix.c.
742    
743    9.  Error texts for pcre_compile() are held as one long string to avoid too
744        much relocation at load time. To find a text, the string is searched,
745        counting zeros. There was no check for running off the end of the string,
746        which could happen if a new error number was added without updating the
747        string.
748    
749    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
750    
751    11. \K was not working if it appeared in an atomic group or in a group that
752        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
753        \K is "not well defined" if used in an assertion. PCRE now accepts it if
754        the assertion is positive, but not if it is negative.
755    
756    12. Change 11 fortuitously reduced the size of the stack frame used in the
757        "match()" function of pcre_exec.c by one pointer. Forthcoming
758        implementation of support for (*MARK) will need an extra pointer on the
759        stack; I have reserved it now, so that the stack frame size does not
760        decrease.
761    
762    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
763        item in branch that calls a recursion is a subroutine call - as in the
764        second branch in the above example - was incorrectly given the compile-
765        time error "recursive call could loop indefinitely" because pcre_compile()
766        was not correctly checking the subroutine for matching a non-empty string.
767    
768    14. The checks for overrunning compiling workspace could trigger after an
769        overrun had occurred. This is a "should never occur" error, but it can be
770        triggered by pathological patterns such as hundreds of nested parentheses.
771        The checks now trigger 100 bytes before the end of the workspace.
772    
773    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
774    
775    
776  Version 8.01 19-Jan-2010  Version 8.01 19-Jan-2010
777  ------------------------  ------------------------

Legend:
Removed from v.496  
changed lines
  Added in v.773

  ViewVC Help
Powered by ViewVC 1.1.5