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revision 702 by ph10, Tue Sep 20 15:45:06 2011 UTC revision 779 by ph10, Fri Dec 2 10:39:32 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.20 12-Sep-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    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
98        systems.
99    
100    
101    Version 8.20 21-Oct-2011
102  ------------------------  ------------------------
103    
104  1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had  1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
# Line 9  Version 8.20 12-Sep-2011 Line 106  Version 8.20 12-Sep-2011
106      Perl has bugs and confusions, a closing square bracket is no longer allowed      Perl has bugs and confusions, a closing square bracket is no longer allowed
107      in a POSIX name. This bug also affected patterns with classes that started      in a POSIX name. This bug also affected patterns with classes that started
108      with full stops.      with full stops.
109    
110  2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no  2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
111      captured substring, but while checking the failing first alternative,      captured substring, but while checking the failing first alternative,
112      substring 1 is temporarily captured. If the output vector supplied to      substring 1 is temporarily captured. If the output vector supplied to
# Line 20  Version 8.20 12-Sep-2011 Line 117  Version 8.20 12-Sep-2011
117      such as /(a)(b)x|abc/ matched against "abc", where the return code      such as /(a)(b)x|abc/ matched against "abc", where the return code
118      indicates that fewer than the maximum number of slots in the ovector have      indicates that fewer than the maximum number of slots in the ovector have
119      been set.      been set.
120    
121  3.  Related to (2) above: when there are more back references in a pattern than  3.  Related to (2) above: when there are more back references in a pattern than
122      slots in the output vector, pcre_exec() uses temporary memory during      slots in the output vector, pcre_exec() uses temporary memory during
123      matching, and copies in the captures as far as possible afterwards. It was      matching, and copies in the captures as far as possible afterwards. It was
# Line 28  Version 8.20 12-Sep-2011 Line 125  Version 8.20 12-Sep-2011
125      that only 2/3 is used for passing back captured substrings. Now it uses      that only 2/3 is used for passing back captured substrings. Now it uses
126      only the first 2/3, for compatibility. This is, of course, another edge      only the first 2/3, for compatibility. This is, of course, another edge
127      case.      case.
128    
129  4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the  4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
130      main code base, and can be used by building with --enable-jit. When this is      main code base, and can be used by building with --enable-jit. When this is
131      done, pcregrep automatically uses it unless --disable-pcregrep-jit or the      done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
132      runtime --no-jit option is given.      runtime --no-jit option is given.
133    
134  5.  When the number of matches in a pcre_dfa_exec() run exactly filled the  5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
135      ovector, the return from the function was zero, implying that there were      ovector, the return from the function was zero, implying that there were
136      other matches that did not fit. The correct "exactly full" value is now      other matches that did not fit. The correct "exactly full" value is now
137      returned.      returned.
138    
139  6.  If a subpattern that was called recursively or as a subroutine contained  6.  If a subpattern that was called recursively or as a subroutine contained
140      (*PRUNE) or any other control that caused it to give a non-standard return,      (*PRUNE) or any other control that caused it to give a non-standard return,
141      invalid errors such as "Error -26 (nested recursion at the same subject      invalid errors such as "Error -26 (nested recursion at the same subject
142      position)" or even infinite loops could occur.      position)" or even infinite loops could occur.
143    
144  7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped  7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
145      computing the minimum length on reaching *ACCEPT, and so ended up with the      computing the minimum length on reaching *ACCEPT, and so ended up with the
146      wrong value of 1 rather than 0. Further investigation indicates that      wrong value of 1 rather than 0. Further investigation indicates that
147      computing a minimum subject length in the presence of *ACCEPT is difficult      computing a minimum subject length in the presence of *ACCEPT is difficult
148      (think back references, subroutine calls), and so I have changed the code      (think back references, subroutine calls), and so I have changed the code
149      so that no minimum is registered for a pattern that contains *ACCEPT.      so that no minimum is registered for a pattern that contains *ACCEPT.
150    
151  8.  If (*THEN) was present in the first (true) branch of a conditional group,  8.  If (*THEN) was present in the first (true) branch of a conditional group,
152      it was not handled as intended.      it was not handled as intended. [But see 16 below.]
153    
154  9.  Replaced RunTest.bat with the much improved version provided by Sheri  9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
155      Pierce.      Sheri Pierce.
156    
157  10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that  10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
158      the first byte in a match must be "a".      the first byte in a match must be "a".
159    
160  11. Change 17 for 8.13 increased the recursion depth for patterns like  11. Change 17 for 8.13 increased the recursion depth for patterns like
161      /a(?:.)*?a/ drastically. I've improved things by remembering whether a      /a(?:.)*?a/ drastically. I've improved things by remembering whether a
162      pattern contains any instances of (*THEN). If it does not, the old      pattern contains any instances of (*THEN). If it does not, the old
163      optimizations are restored. It would be nice to do this on a per-group      optimizations are restored. It would be nice to do this on a per-group
164      basis, but at the moment that is not feasible.      basis, but at the moment that is not feasible.
165    
166    12. In some environments, the output of pcretest -C is CRLF terminated. This
167        broke RunTest's code that checks for the link size. A single white space
168        character after the value is now allowed for.
169    
170    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
171        For "fr", it uses the Windows-specific input and output files.
172    
173    14. If (*THEN) appeared in a group that was called recursively or as a
174        subroutine, it did not work as intended. [But see next item.]
175    
176    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
177        pattern fragments (but not containing any | characters). If A and B are
178        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
179        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
180        D. In other words, Perl considers parentheses that do not contain any |
181        characters to be part of a surrounding alternative, whereas PCRE was
182        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
183        differently. PCRE now behaves in the same way as Perl, except in the case
184        of subroutine/recursion calls such as (?1) which have in any case always
185        been different (but PCRE had them first :-).
186    
187    16. Related to 15 above: Perl does not treat the | in a conditional group as
188        creating alternatives. Such a group is treated in the same way as an
189        ordinary group without any | characters when processing (*THEN). PCRE has
190        been changed to match Perl's behaviour.
191    
192    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
193        RunGrepTest script failed.
194    
195    18. Change 22 for version 13 caused atomic groups to use more stack. This is
196        inevitable for groups that contain captures, but it can lead to a lot of
197        stack use in large patterns. The old behaviour has been restored for atomic
198        groups that do not contain any capturing parentheses.
199    
200    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
201        suppress the check for a minimum subject length at run time. (If it was
202        given to pcre_exec() or pcre_dfa_exec() it did work.)
203    
204    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
205        fail to work when decoding hex characters in data strings in EBCDIC
206        environments.
207    
208    21. It appears that in at least one Mac OS environment, the isxdigit() function
209        is implemented as a macro that evaluates to its argument more than once,
210        contravening the C 90 Standard (I haven't checked a later standard). There
211        was an instance in pcretest which caused it to go wrong when processing
212        \x{...} escapes in subject strings. The has been rewritten to avoid using
213        things like p++ in the argument of isxdigit().
214    
215    
216  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
217  ------------------------  ------------------------
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