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

Diff of /code/trunk/ChangeLog

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

revision 659 by ph10, Tue Aug 16 09:48:29 2011 UTC revision 745 by ph10, Mon Nov 14 11:41:03 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    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    
24    Version 8.20 21-Oct-2011
25    ------------------------
26    
27    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
28        a POSIX class. After further experiments with Perl, which convinced me that
29        Perl has bugs and confusions, a closing square bracket is no longer allowed
30        in a POSIX name. This bug also affected patterns with classes that started
31        with full stops.
32    
33    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
34        captured substring, but while checking the failing first alternative,
35        substring 1 is temporarily captured. If the output vector supplied to
36        pcre_exec() was not big enough for this capture, the yield of the function
37        was still zero ("insufficient space for captured substrings"). This cannot
38        be totally fixed without adding another stack variable, which seems a lot
39        of expense for a edge case. However, I have improved the situation in cases
40        such as /(a)(b)x|abc/ matched against "abc", where the return code
41        indicates that fewer than the maximum number of slots in the ovector have
42        been set.
43    
44    3.  Related to (2) above: when there are more back references in a pattern than
45        slots in the output vector, pcre_exec() uses temporary memory during
46        matching, and copies in the captures as far as possible afterwards. It was
47        using the entire output vector, but this conflicts with the specification
48        that only 2/3 is used for passing back captured substrings. Now it uses
49        only the first 2/3, for compatibility. This is, of course, another edge
50        case.
51    
52    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
53        main code base, and can be used by building with --enable-jit. When this is
54        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
55        runtime --no-jit option is given.
56    
57    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
58        ovector, the return from the function was zero, implying that there were
59        other matches that did not fit. The correct "exactly full" value is now
60        returned.
61    
62    6.  If a subpattern that was called recursively or as a subroutine contained
63        (*PRUNE) or any other control that caused it to give a non-standard return,
64        invalid errors such as "Error -26 (nested recursion at the same subject
65        position)" or even infinite loops could occur.
66    
67    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
68        computing the minimum length on reaching *ACCEPT, and so ended up with the
69        wrong value of 1 rather than 0. Further investigation indicates that
70        computing a minimum subject length in the presence of *ACCEPT is difficult
71        (think back references, subroutine calls), and so I have changed the code
72        so that no minimum is registered for a pattern that contains *ACCEPT.
73    
74    8.  If (*THEN) was present in the first (true) branch of a conditional group,
75        it was not handled as intended. [But see 16 below.]
76    
77    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
78        Sheri Pierce.
79    
80    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
81        the first byte in a match must be "a".
82    
83    11. Change 17 for 8.13 increased the recursion depth for patterns like
84        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
85        pattern contains any instances of (*THEN). If it does not, the old
86        optimizations are restored. It would be nice to do this on a per-group
87        basis, but at the moment that is not feasible.
88    
89    12. In some environments, the output of pcretest -C is CRLF terminated. This
90        broke RunTest's code that checks for the link size. A single white space
91        character after the value is now allowed for.
92    
93    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
94        For "fr", it uses the Windows-specific input and output files.
95    
96    14. If (*THEN) appeared in a group that was called recursively or as a
97        subroutine, it did not work as intended. [But see next item.]
98    
99    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
100        pattern fragments (but not containing any | characters). If A and B are
101        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
102        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
103        D. In other words, Perl considers parentheses that do not contain any |
104        characters to be part of a surrounding alternative, whereas PCRE was
105        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
106        differently. PCRE now behaves in the same way as Perl, except in the case
107        of subroutine/recursion calls such as (?1) which have in any case always
108        been different (but PCRE had them first :-).
109    
110    16. Related to 15 above: Perl does not treat the | in a conditional group as
111        creating alternatives. Such a group is treated in the same way as an
112        ordinary group without any | characters when processing (*THEN). PCRE has
113        been changed to match Perl's behaviour.
114    
115    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
116        RunGrepTest script failed.
117    
118    18. Change 22 for version 13 caused atomic groups to use more stack. This is
119        inevitable for groups that contain captures, but it can lead to a lot of
120        stack use in large patterns. The old behaviour has been restored for atomic
121        groups that do not contain any capturing parentheses.
122    
123    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
124        suppress the check for a minimum subject length at run time. (If it was
125        given to pcre_exec() or pcre_dfa_exec() it did work.)
126    
127    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
128        fail to work when decoding hex characters in data strings in EBCDIC
129        environments.
130    
131    21. It appears that in at least one Mac OS environment, the isxdigit() function
132        is implemented as a macro that evaluates to its argument more than once,
133        contravening the C 90 Standard (I haven't checked a later standard). There
134        was an instance in pcretest which caused it to go wrong when processing
135        \x{...} escapes in subject strings. The has been rewritten to avoid using
136        things like p++ in the argument of isxdigit().
137    
138    
139  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
140  ------------------------  ------------------------
141    
# Line 98  Version 8.13 16-Aug-2011 Line 233  Version 8.13 16-Aug-2011
233      tail recursion to cut down on stack usage. Unfortunately, now that there is      tail recursion to cut down on stack usage. Unfortunately, now that there is
234      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
235      no longer possible because the return has to be checked for (*THEN). These      no longer possible because the return has to be checked for (*THEN). These
236      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
237    
238  18. If a pattern containing \R was studied, it was assumed that \R always  18. If a pattern containing \R was studied, it was assumed that \R always
239      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be
# Line 189  Version 8.13 16-Aug-2011 Line 324  Version 8.13 16-Aug-2011
324      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
325      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
326      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
327      more like Perl.      more like Perl. (But see 8.20/1 above.)
328    
329  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this  38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
330      was because it thought it was \N{name}, which is not supported).      was because it thought it was \N{name}, which is not supported).

Legend:
Removed from v.659  
changed lines
  Added in v.745

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12