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revision 654 by ph10, Tue Aug 2 11:00:40 2011 UTC revision 778 by ph10, Thu Dec 1 17:38:47 2011 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 02-Aug-2011  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    19. If the /S+ option was used in pcretest to study a pattern using JIT,
88        subsequent uses of /S (without +) incorrectly behaved like /S+.
89    
90    21. Retrieve executable code size support for the JIT compiler and fixing
91        some warnings.
92    
93    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
94        not work when the shorter character appeared right at the end of the
95        subject string.
96    
97    
98    Version 8.20 21-Oct-2011
99    ------------------------
100    
101    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
102        a POSIX class. After further experiments with Perl, which convinced me that
103        Perl has bugs and confusions, a closing square bracket is no longer allowed
104        in a POSIX name. This bug also affected patterns with classes that started
105        with full stops.
106    
107    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
108        captured substring, but while checking the failing first alternative,
109        substring 1 is temporarily captured. If the output vector supplied to
110        pcre_exec() was not big enough for this capture, the yield of the function
111        was still zero ("insufficient space for captured substrings"). This cannot
112        be totally fixed without adding another stack variable, which seems a lot
113        of expense for a edge case. However, I have improved the situation in cases
114        such as /(a)(b)x|abc/ matched against "abc", where the return code
115        indicates that fewer than the maximum number of slots in the ovector have
116        been set.
117    
118    3.  Related to (2) above: when there are more back references in a pattern than
119        slots in the output vector, pcre_exec() uses temporary memory during
120        matching, and copies in the captures as far as possible afterwards. It was
121        using the entire output vector, but this conflicts with the specification
122        that only 2/3 is used for passing back captured substrings. Now it uses
123        only the first 2/3, for compatibility. This is, of course, another edge
124        case.
125    
126    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
127        main code base, and can be used by building with --enable-jit. When this is
128        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
129        runtime --no-jit option is given.
130    
131    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
132        ovector, the return from the function was zero, implying that there were
133        other matches that did not fit. The correct "exactly full" value is now
134        returned.
135    
136    6.  If a subpattern that was called recursively or as a subroutine contained
137        (*PRUNE) or any other control that caused it to give a non-standard return,
138        invalid errors such as "Error -26 (nested recursion at the same subject
139        position)" or even infinite loops could occur.
140    
141    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
142        computing the minimum length on reaching *ACCEPT, and so ended up with the
143        wrong value of 1 rather than 0. Further investigation indicates that
144        computing a minimum subject length in the presence of *ACCEPT is difficult
145        (think back references, subroutine calls), and so I have changed the code
146        so that no minimum is registered for a pattern that contains *ACCEPT.
147    
148    8.  If (*THEN) was present in the first (true) branch of a conditional group,
149        it was not handled as intended. [But see 16 below.]
150    
151    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
152        Sheri Pierce.
153    
154    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
155        the first byte in a match must be "a".
156    
157    11. Change 17 for 8.13 increased the recursion depth for patterns like
158        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
159        pattern contains any instances of (*THEN). If it does not, the old
160        optimizations are restored. It would be nice to do this on a per-group
161        basis, but at the moment that is not feasible.
162    
163    12. In some environments, the output of pcretest -C is CRLF terminated. This
164        broke RunTest's code that checks for the link size. A single white space
165        character after the value is now allowed for.
166    
167    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
168        For "fr", it uses the Windows-specific input and output files.
169    
170    14. If (*THEN) appeared in a group that was called recursively or as a
171        subroutine, it did not work as intended. [But see next item.]
172    
173    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
174        pattern fragments (but not containing any | characters). If A and B are
175        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
176        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
177        D. In other words, Perl considers parentheses that do not contain any |
178        characters to be part of a surrounding alternative, whereas PCRE was
179        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
180        differently. PCRE now behaves in the same way as Perl, except in the case
181        of subroutine/recursion calls such as (?1) which have in any case always
182        been different (but PCRE had them first :-).
183    
184    16. Related to 15 above: Perl does not treat the | in a conditional group as
185        creating alternatives. Such a group is treated in the same way as an
186        ordinary group without any | characters when processing (*THEN). PCRE has
187        been changed to match Perl's behaviour.
188    
189    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
190        RunGrepTest script failed.
191    
192    18. Change 22 for version 13 caused atomic groups to use more stack. This is
193        inevitable for groups that contain captures, but it can lead to a lot of
194        stack use in large patterns. The old behaviour has been restored for atomic
195        groups that do not contain any capturing parentheses.
196    
197    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
198        suppress the check for a minimum subject length at run time. (If it was
199        given to pcre_exec() or pcre_dfa_exec() it did work.)
200    
201    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
202        fail to work when decoding hex characters in data strings in EBCDIC
203        environments.
204    
205    21. It appears that in at least one Mac OS environment, the isxdigit() function
206        is implemented as a macro that evaluates to its argument more than once,
207        contravening the C 90 Standard (I haven't checked a later standard). There
208        was an instance in pcretest which caused it to go wrong when processing
209        \x{...} escapes in subject strings. The has been rewritten to avoid using
210        things like p++ in the argument of isxdigit().
211    
212    
213    Version 8.13 16-Aug-2011
214  ------------------------  ------------------------
215    
216  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 98  Version 8.13 02-Aug-2011 Line 307  Version 8.13 02-Aug-2011
307      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
308      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
309      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
310      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
311    
312  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
313      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 02-Aug-2011 Line 398  Version 8.13 02-Aug-2011
398      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
399      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
400      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
401      more like Perl.      more like Perl. (But see 8.20/1 above.)
402    
403  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
404      was because it thought it was \N{name}, which is not supported).      was because it thought it was \N{name}, which is not supported).
# Line 224  Version 8.13 02-Aug-2011 Line 433  Version 8.13 02-Aug-2011
433      (a) The default value of the buffer size parameter has been increased from      (a) The default value of the buffer size parameter has been increased from
434          8K to 20K. (The actual buffer used is three times this size.)          8K to 20K. (The actual buffer used is three times this size.)
435    
436      (b) The default can be changed by ./configure --with-pcregrep-bufsiz when      (b) The default can be changed by ./configure --with-pcregrep-bufsize when
437          PCRE is built.          PCRE is built.
438    
439      (c) A --buffer-size=n option has been added to pcregrep, to allow the size      (c) A --buffer-size=n option has been added to pcregrep, to allow the size
# Line 246  Version 8.13 02-Aug-2011 Line 455  Version 8.13 02-Aug-2011
455      complete match instead of a partial match. This bug was dependent on both      complete match instead of a partial match. This bug was dependent on both
456      the PCRE_UTF8 and PCRE_DOTALL options being set.      the PCRE_UTF8 and PCRE_DOTALL options being set.
457    
458    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
459        starting byte set, because \b was not being ignored.
460    
461    
462  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
463  ------------------------  ------------------------

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