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revision 659 by ph10, Tue Aug 16 09:48:29 2011 UTC revision 912 by ph10, Sun Feb 12 16:53:39 2012 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.31
5    -----------------------------
6    
7    1.  Fixing a wrong JIT test case and some compiler warnings.
8    
9    2.  Removed a bashism from the RunTest script.
10    
11    
12    Version 8.30 04-February-2012
13    -----------------------------
14    
15    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
16        name is defined in ctype.h.
17    
18    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
19        only in quite long subpatterns.
20    
21    3.  Removed the function pcre_info(), which has been obsolete and deprecated
22        since it was replaced by pcre_fullinfo() in February 2000.
23    
24    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
25        match a (*MARK), and the match failed at the start of the subject, a
26        reference to memory before the start of the subject could occur. This bug
27        was introduced by fix 17 of release 8.21.
28    
29    5.  A reference to an unset group with zero minimum repetition was giving
30        totally wrong answers (in non-JavaScript-compatibility mode). For example,
31        /(another)?(\1?)test/ matched against "hello world test". This bug was
32        introduced in release 8.13.
33    
34    6.  Add support for 16-bit character strings (a large amount of work involving
35        many changes and refactorings).
36    
37    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
38        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
39        from a file.
40    
41    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
42        rounding is not applied in this particular case).
43    
44    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
45        if they appear, or are escaped, in patterns.
46    
47    10. Get rid of a number of -Wunused-but-set-variable warnings.
48    
49    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
50        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
51        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
52        also returns the mark "x". This bug applied to capturing parentheses,
53        non-capturing parentheses, and atomic parentheses. It also applied to some
54        assertions.
55    
56    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
57        information out of configure.ac instead of relying on pcre.h.generic, which
58        is not stored in the repository.
59    
60    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
61        -lreadline.
62    
63    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
64    
65    15. Applied Graycode's patch to put the top-level frame on the stack rather
66        than the heap when not using the stack for recursion. This gives a
67        performance improvement in many cases when recursion is not deep.
68    
69    16. Experimental code added to "pcretest -C" to output the stack frame size.
70    
71    
72    Version 8.21 12-Dec-2011
73    ------------------------
74    
75    1.  Updating the JIT compiler.
76    
77    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
78        are added as well.
79    
80    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
81        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
82        calling _pcre_jit_exec. Some extra comments are added.
83    
84    4.  (*MARK) settings inside atomic groups that do not contain any capturing
85        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
86        was introduced by change 18 for 8.20.
87    
88    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
89        ECMA-262 standard.
90    
91    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
92        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
93        This bug was probably introduced by change 9 of 8.13.
94    
95    7.  While fixing 6 above, I noticed that a number of other items were being
96        incorrectly rejected as "not fixed length". This arose partly because newer
97        opcodes had not been added to the fixed-length checking code. I have (a)
98        corrected the bug and added tests for these items, and (b) arranged for an
99        error to occur if an unknown opcode is encountered while checking for fixed
100        length instead of just assuming "not fixed length". The items that were
101        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
102        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
103        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
104    
105    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
106        being incorrectly compiled and would have given unpredicatble results.
107    
108    9.  A possessively repeated subpattern with minimum repeat count greater than
109        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
110        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
111        the first (A) could occur when it should not.
112    
113    10. Add a cast and remove a redundant test from the code.
114    
115    11. JIT should use pcre_malloc/pcre_free for allocation.
116    
117    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
118        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
119        is anything other than /usr, -L is still shown).
120    
121    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
122    
123    14. Perl does not support \N without a following name in a [] class; PCRE now
124        also gives an error.
125    
126    15. If a forward reference was repeated with an upper limit of around 2000,
127        it caused the error "internal error: overran compiling workspace". The
128        maximum number of forward references (including repeats) was limited by the
129        internal workspace, and dependent on the LINK_SIZE. The code has been
130        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
131        the default depends on LINK_SIZE. There is a new upper limit (for safety)
132        of around 200,000 forward references. While doing this, I also speeded up
133        the filling in of repeated forward references.
134    
135    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
136        incorrectly expecting the subject to contain another "a" after the start.
137    
138    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
139        in the match, the SKIP should be ignored. This was not happening; instead
140        the SKIP was being treated as NOMATCH. For patterns such as
141        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
142        tested.
143    
144    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
145        now much more compatible with Perl, in particular in cases where the result
146        is a non-match for a non-anchored pattern. For example, if
147        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
148        "m", where previously it did not return a name. A side effect of this
149        change is that for partial matches, the last encountered mark name is
150        returned, as for non matches. A number of tests that were previously not
151        Perl-compatible have been moved into the Perl-compatible test files. The
152        refactoring has had the pleasing side effect of removing one argument from
153        the match() function, thus reducing its stack requirements.
154    
155    19. If the /S+ option was used in pcretest to study a pattern using JIT,
156        subsequent uses of /S (without +) incorrectly behaved like /S+.
157    
158    21. Retrieve executable code size support for the JIT compiler and fixing
159        some warnings.
160    
161    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
162        not work when the shorter character appeared right at the end of the
163        subject string.
164    
165    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
166        systems.
167    
168    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
169        output it when the /M option is used in pcretest.
170    
171    25. The CheckMan script was not being included in the distribution. Also, added
172        an explicit "perl" to run Perl scripts from the PrepareRelease script
173        because this is reportedly needed in Windows.
174    
175    26. If study data was being save in a file and studying had not found a set of
176        "starts with" bytes for the pattern, the data written to the file (though
177        never used) was taken from uninitialized memory and so caused valgrind to
178        complain.
179    
180    27. Updated RunTest.bat as provided by Sheri Pierce.
181    
182    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
183    
184    29. Computation of memory usage for the table of capturing group names was
185        giving an unnecessarily large value.
186    
187    
188    Version 8.20 21-Oct-2011
189    ------------------------
190    
191    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
192        a POSIX class. After further experiments with Perl, which convinced me that
193        Perl has bugs and confusions, a closing square bracket is no longer allowed
194        in a POSIX name. This bug also affected patterns with classes that started
195        with full stops.
196    
197    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
198        captured substring, but while checking the failing first alternative,
199        substring 1 is temporarily captured. If the output vector supplied to
200        pcre_exec() was not big enough for this capture, the yield of the function
201        was still zero ("insufficient space for captured substrings"). This cannot
202        be totally fixed without adding another stack variable, which seems a lot
203        of expense for a edge case. However, I have improved the situation in cases
204        such as /(a)(b)x|abc/ matched against "abc", where the return code
205        indicates that fewer than the maximum number of slots in the ovector have
206        been set.
207    
208    3.  Related to (2) above: when there are more back references in a pattern than
209        slots in the output vector, pcre_exec() uses temporary memory during
210        matching, and copies in the captures as far as possible afterwards. It was
211        using the entire output vector, but this conflicts with the specification
212        that only 2/3 is used for passing back captured substrings. Now it uses
213        only the first 2/3, for compatibility. This is, of course, another edge
214        case.
215    
216    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
217        main code base, and can be used by building with --enable-jit. When this is
218        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
219        runtime --no-jit option is given.
220    
221    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
222        ovector, the return from the function was zero, implying that there were
223        other matches that did not fit. The correct "exactly full" value is now
224        returned.
225    
226    6.  If a subpattern that was called recursively or as a subroutine contained
227        (*PRUNE) or any other control that caused it to give a non-standard return,
228        invalid errors such as "Error -26 (nested recursion at the same subject
229        position)" or even infinite loops could occur.
230    
231    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
232        computing the minimum length on reaching *ACCEPT, and so ended up with the
233        wrong value of 1 rather than 0. Further investigation indicates that
234        computing a minimum subject length in the presence of *ACCEPT is difficult
235        (think back references, subroutine calls), and so I have changed the code
236        so that no minimum is registered for a pattern that contains *ACCEPT.
237    
238    8.  If (*THEN) was present in the first (true) branch of a conditional group,
239        it was not handled as intended. [But see 16 below.]
240    
241    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
242        Sheri Pierce.
243    
244    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
245        the first byte in a match must be "a".
246    
247    11. Change 17 for 8.13 increased the recursion depth for patterns like
248        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
249        pattern contains any instances of (*THEN). If it does not, the old
250        optimizations are restored. It would be nice to do this on a per-group
251        basis, but at the moment that is not feasible.
252    
253    12. In some environments, the output of pcretest -C is CRLF terminated. This
254        broke RunTest's code that checks for the link size. A single white space
255        character after the value is now allowed for.
256    
257    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
258        For "fr", it uses the Windows-specific input and output files.
259    
260    14. If (*THEN) appeared in a group that was called recursively or as a
261        subroutine, it did not work as intended. [But see next item.]
262    
263    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
264        pattern fragments (but not containing any | characters). If A and B are
265        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
266        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
267        D. In other words, Perl considers parentheses that do not contain any |
268        characters to be part of a surrounding alternative, whereas PCRE was
269        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
270        differently. PCRE now behaves in the same way as Perl, except in the case
271        of subroutine/recursion calls such as (?1) which have in any case always
272        been different (but PCRE had them first :-).
273    
274    16. Related to 15 above: Perl does not treat the | in a conditional group as
275        creating alternatives. Such a group is treated in the same way as an
276        ordinary group without any | characters when processing (*THEN). PCRE has
277        been changed to match Perl's behaviour.
278    
279    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
280        RunGrepTest script failed.
281    
282    18. Change 22 for version 13 caused atomic groups to use more stack. This is
283        inevitable for groups that contain captures, but it can lead to a lot of
284        stack use in large patterns. The old behaviour has been restored for atomic
285        groups that do not contain any capturing parentheses.
286    
287    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
288        suppress the check for a minimum subject length at run time. (If it was
289        given to pcre_exec() or pcre_dfa_exec() it did work.)
290    
291    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
292        fail to work when decoding hex characters in data strings in EBCDIC
293        environments.
294    
295    21. It appears that in at least one Mac OS environment, the isxdigit() function
296        is implemented as a macro that evaluates to its argument more than once,
297        contravening the C 90 Standard (I haven't checked a later standard). There
298        was an instance in pcretest which caused it to go wrong when processing
299        \x{...} escapes in subject strings. The has been rewritten to avoid using
300        things like p++ in the argument of isxdigit().
301    
302    
303  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
304  ------------------------  ------------------------
305    
# Line 98  Version 8.13 16-Aug-2011 Line 397  Version 8.13 16-Aug-2011
397      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
398      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
399      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
400      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
401    
402  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
403      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 488  Version 8.13 16-Aug-2011
488      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,      For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
489      unescaped square brackets may also appear as part of class names. For      unescaped square brackets may also appear as part of class names. For
490      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves      example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
491      more like Perl.      more like Perl. (But see 8.20/1 above.)
492    
493  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
494      was because it thought it was \N{name}, which is not supported).      was because it thought it was \N{name}, which is not supported).

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