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revision 701 by ph10, Tue Sep 20 11:30:56 2011 UTC revision 807 by ph10, Sun Dec 18 10:03:38 2011 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.20 12-Sep-2011  Version 8.22
5    ------------
6    
7    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
8        name is defined in ctype.h.
9    
10    2.  Fixed a bug in the code for calculating the fixed length of lookbehind
11        assertions.
12    
13    
14    Version 8.21 12-Dec-2011
15    ------------------------
16    
17    1.  Updating the JIT compiler.
18    
19    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
20        are added as well.
21    
22    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
23        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
24        calling _pcre_jit_exec. Some extra comments are added.
25    
26    4.  (*MARK) settings inside atomic groups that do not contain any capturing
27        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
28        was introduced by change 18 for 8.20.
29    
30    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
31        ECMA-262 standard.
32    
33    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
34        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
35        This bug was probably introduced by change 9 of 8.13.
36    
37    7.  While fixing 6 above, I noticed that a number of other items were being
38        incorrectly rejected as "not fixed length". This arose partly because newer
39        opcodes had not been added to the fixed-length checking code. I have (a)
40        corrected the bug and added tests for these items, and (b) arranged for an
41        error to occur if an unknown opcode is encountered while checking for fixed
42        length instead of just assuming "not fixed length". The items that were
43        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
44        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
45        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
46    
47    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
48        being incorrectly compiled and would have given unpredicatble results.
49    
50    9.  A possessively repeated subpattern with minimum repeat count greater than
51        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
52        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
53        the first (A) could occur when it should not.
54    
55    10. Add a cast and remove a redundant test from the code.
56    
57    11. JIT should use pcre_malloc/pcre_free for allocation.
58    
59    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
60        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
61        is anything other than /usr, -L is still shown).
62    
63    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
64    
65    14. Perl does not support \N without a following name in a [] class; PCRE now
66        also gives an error.
67    
68    15. If a forward reference was repeated with an upper limit of around 2000,
69        it caused the error "internal error: overran compiling workspace". The
70        maximum number of forward references (including repeats) was limited by the
71        internal workspace, and dependent on the LINK_SIZE. The code has been
72        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
73        the default depends on LINK_SIZE. There is a new upper limit (for safety)
74        of around 200,000 forward references. While doing this, I also speeded up
75        the filling in of repeated forward references.
76    
77    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
78        incorrectly expecting the subject to contain another "a" after the start.
79    
80    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
81        in the match, the SKIP should be ignored. This was not happening; instead
82        the SKIP was being treated as NOMATCH. For patterns such as
83        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
84        tested.
85    
86    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
87        now much more compatible with Perl, in particular in cases where the result
88        is a non-match for a non-anchored pattern. For example, if
89        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
90        "m", where previously it did not return a name. A side effect of this
91        change is that for partial matches, the last encountered mark name is
92        returned, as for non matches. A number of tests that were previously not
93        Perl-compatible have been moved into the Perl-compatible test files. The
94        refactoring has had the pleasing side effect of removing one argument from
95        the match() function, thus reducing its stack requirements.
96    
97    19. If the /S+ option was used in pcretest to study a pattern using JIT,
98        subsequent uses of /S (without +) incorrectly behaved like /S+.
99    
100    21. Retrieve executable code size support for the JIT compiler and fixing
101        some warnings.
102    
103    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
104        not work when the shorter character appeared right at the end of the
105        subject string.
106    
107    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
108        systems.
109    
110    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
111        output it when the /M option is used in pcretest.
112    
113    25. The CheckMan script was not being included in the distribution. Also, added
114        an explicit "perl" to run Perl scripts from the PrepareRelease script
115        because this is reportedly needed in Windows.
116    
117    26. If study data was being save in a file and studying had not found a set of
118        "starts with" bytes for the pattern, the data written to the file (though
119        never used) was taken from uninitialized memory and so caused valgrind to
120        complain.
121    
122    27. Updated RunTest.bat as provided by Sheri Pierce.
123    
124    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
125    
126    29. Computation of memory usage for the table of capturing group names was
127        giving an unnecessarily large value.
128    
129    
130    Version 8.20 21-Oct-2011
131  ------------------------  ------------------------
132    
133  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 135  Version 8.20 12-Sep-2011
135      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
136      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
137      with full stops.      with full stops.
138    
139  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
140      captured substring, but while checking the failing first alternative,      captured substring, but while checking the failing first alternative,
141      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 146  Version 8.20 12-Sep-2011
146      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
147      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
148      been set.      been set.
149    
150  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
151      slots in the output vector, pcre_exec() uses temporary memory during      slots in the output vector, pcre_exec() uses temporary memory during
152      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 154  Version 8.20 12-Sep-2011
154      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
155      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
156      case.      case.
157    
158  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
159      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
160      done, pcregrep automatically uses it unless --disable-pcregrep-jit or the      done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
161      runtime --no-jit option is given.      runtime --no-jit option is given.
162    
163  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
164      ovector, the return from the function was zero, implying that there were      ovector, the return from the function was zero, implying that there were
165      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
166      returned.      returned.
167    
168  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
169      (*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,
170      invalid errors such as "Error -26 (nested recursion at the same subject      invalid errors such as "Error -26 (nested recursion at the same subject
171      position)" or even infinite loops could occur.      position)" or even infinite loops could occur.
172    
173  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
174      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
175      wrong value of 1 rather than 0. Further investigation indicates that      wrong value of 1 rather than 0. Further investigation indicates that
176      computing a minimum subject length in the presence of *ACCEPT is difficult      computing a minimum subject length in the presence of *ACCEPT is difficult
177      (think back references, subroutine calls), and so I have changed the code      (think back references, subroutine calls), and so I have changed the code
178      so that no minimum is registered for a pattern that contains *ACCEPT.      so that no minimum is registered for a pattern that contains *ACCEPT.
179    
180  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,
181      it was not handled as intended.      it was not handled as intended. [But see 16 below.]
182    
183  9.  Replaced RunTest.bat with the much improved version provided by Sheri  9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
184      Pierce.      Sheri Pierce.
185    
186  10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that  10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
187      the first byte in a match must be "a".      the first byte in a match must be "a".
188    
189    11. Change 17 for 8.13 increased the recursion depth for patterns like
190        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
191        pattern contains any instances of (*THEN). If it does not, the old
192        optimizations are restored. It would be nice to do this on a per-group
193        basis, but at the moment that is not feasible.
194    
195    12. In some environments, the output of pcretest -C is CRLF terminated. This
196        broke RunTest's code that checks for the link size. A single white space
197        character after the value is now allowed for.
198    
199    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
200        For "fr", it uses the Windows-specific input and output files.
201    
202    14. If (*THEN) appeared in a group that was called recursively or as a
203        subroutine, it did not work as intended. [But see next item.]
204    
205    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
206        pattern fragments (but not containing any | characters). If A and B are
207        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
208        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
209        D. In other words, Perl considers parentheses that do not contain any |
210        characters to be part of a surrounding alternative, whereas PCRE was
211        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
212        differently. PCRE now behaves in the same way as Perl, except in the case
213        of subroutine/recursion calls such as (?1) which have in any case always
214        been different (but PCRE had them first :-).
215    
216    16. Related to 15 above: Perl does not treat the | in a conditional group as
217        creating alternatives. Such a group is treated in the same way as an
218        ordinary group without any | characters when processing (*THEN). PCRE has
219        been changed to match Perl's behaviour.
220    
221    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
222        RunGrepTest script failed.
223    
224    18. Change 22 for version 13 caused atomic groups to use more stack. This is
225        inevitable for groups that contain captures, but it can lead to a lot of
226        stack use in large patterns. The old behaviour has been restored for atomic
227        groups that do not contain any capturing parentheses.
228    
229    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
230        suppress the check for a minimum subject length at run time. (If it was
231        given to pcre_exec() or pcre_dfa_exec() it did work.)
232    
233    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
234        fail to work when decoding hex characters in data strings in EBCDIC
235        environments.
236    
237    21. It appears that in at least one Mac OS environment, the isxdigit() function
238        is implemented as a macro that evaluates to its argument more than once,
239        contravening the C 90 Standard (I haven't checked a later standard). There
240        was an instance in pcretest which caused it to go wrong when processing
241        \x{...} escapes in subject strings. The has been rewritten to avoid using
242        things like p++ in the argument of isxdigit().
243    
244    
245  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
246  ------------------------  ------------------------
# Line 158  Version 8.13 16-Aug-2011 Line 339  Version 8.13 16-Aug-2011
339      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
340      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
341      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
342      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
343    
344  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
345      matched two bytes, thus causing the minimum subject length to be      matched two bytes, thus causing the minimum subject length to be

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