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revision 699 by ph10, Tue Sep 20 10:46:54 2011 UTC revision 919 by ph10, Fri Feb 17 11:48:02 2012 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.20 12-Sep-2011  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    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
12        to unsigned type, result still unsigned" that was given by an MS compiler
13        on encountering the code "-sizeof(xxx)".
14    
15    4.  Partial matching support is added to the JIT compiler.
16    
17    5.  Fixed several bugs concerned with partial matching of items that consist
18        of more than one character:
19    
20        (a) /^(..)\1/ did not partially match "aba" because checking references was
21            done on an "all or nothing" basis. This also applied to repeated
22            references.
23    
24        (b) \R did not give a hard partial match if \r was found at the end of the
25            subject.
26    
27        (c) \X did not give a hard partial match after matching one or more
28            characters at the end of the subject.
29    
30        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
31            a partial match for the string "\r".
32    
33        (e) When newline was set to CRLF, the metacharacter "." did not recognize
34            a partial match for a CR character at the end of the subject string.
35    
36    
37    Version 8.30 04-February-2012
38    -----------------------------
39    
40    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
41        name is defined in ctype.h.
42    
43    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
44        only in quite long subpatterns.
45    
46    3.  Removed the function pcre_info(), which has been obsolete and deprecated
47        since it was replaced by pcre_fullinfo() in February 2000.
48    
49    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
50        match a (*MARK), and the match failed at the start of the subject, a
51        reference to memory before the start of the subject could occur. This bug
52        was introduced by fix 17 of release 8.21.
53    
54    5.  A reference to an unset group with zero minimum repetition was giving
55        totally wrong answers (in non-JavaScript-compatibility mode). For example,
56        /(another)?(\1?)test/ matched against "hello world test". This bug was
57        introduced in release 8.13.
58    
59    6.  Add support for 16-bit character strings (a large amount of work involving
60        many changes and refactorings).
61    
62    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
63        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
64        from a file.
65    
66    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
67        rounding is not applied in this particular case).
68    
69    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
70        if they appear, or are escaped, in patterns.
71    
72    10. Get rid of a number of -Wunused-but-set-variable warnings.
73    
74    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
75        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
76        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
77        also returns the mark "x". This bug applied to capturing parentheses,
78        non-capturing parentheses, and atomic parentheses. It also applied to some
79        assertions.
80    
81    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
82        information out of configure.ac instead of relying on pcre.h.generic, which
83        is not stored in the repository.
84    
85    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
86        -lreadline.
87    
88    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
89    
90    15. Applied Graycode's patch to put the top-level frame on the stack rather
91        than the heap when not using the stack for recursion. This gives a
92        performance improvement in many cases when recursion is not deep.
93    
94    16. Experimental code added to "pcretest -C" to output the stack frame size.
95    
96    
97    Version 8.21 12-Dec-2011
98    ------------------------
99    
100    1.  Updating the JIT compiler.
101    
102    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
103        are added as well.
104    
105    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
106        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
107        calling _pcre_jit_exec. Some extra comments are added.
108    
109    4.  (*MARK) settings inside atomic groups that do not contain any capturing
110        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
111        was introduced by change 18 for 8.20.
112    
113    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
114        ECMA-262 standard.
115    
116    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
117        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
118        This bug was probably introduced by change 9 of 8.13.
119    
120    7.  While fixing 6 above, I noticed that a number of other items were being
121        incorrectly rejected as "not fixed length". This arose partly because newer
122        opcodes had not been added to the fixed-length checking code. I have (a)
123        corrected the bug and added tests for these items, and (b) arranged for an
124        error to occur if an unknown opcode is encountered while checking for fixed
125        length instead of just assuming "not fixed length". The items that were
126        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
127        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
128        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
129    
130    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
131        being incorrectly compiled and would have given unpredicatble results.
132    
133    9.  A possessively repeated subpattern with minimum repeat count greater than
134        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
135        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
136        the first (A) could occur when it should not.
137    
138    10. Add a cast and remove a redundant test from the code.
139    
140    11. JIT should use pcre_malloc/pcre_free for allocation.
141    
142    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
143        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
144        is anything other than /usr, -L is still shown).
145    
146    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
147    
148    14. Perl does not support \N without a following name in a [] class; PCRE now
149        also gives an error.
150    
151    15. If a forward reference was repeated with an upper limit of around 2000,
152        it caused the error "internal error: overran compiling workspace". The
153        maximum number of forward references (including repeats) was limited by the
154        internal workspace, and dependent on the LINK_SIZE. The code has been
155        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
156        the default depends on LINK_SIZE. There is a new upper limit (for safety)
157        of around 200,000 forward references. While doing this, I also speeded up
158        the filling in of repeated forward references.
159    
160    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
161        incorrectly expecting the subject to contain another "a" after the start.
162    
163    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
164        in the match, the SKIP should be ignored. This was not happening; instead
165        the SKIP was being treated as NOMATCH. For patterns such as
166        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
167        tested.
168    
169    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
170        now much more compatible with Perl, in particular in cases where the result
171        is a non-match for a non-anchored pattern. For example, if
172        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
173        "m", where previously it did not return a name. A side effect of this
174        change is that for partial matches, the last encountered mark name is
175        returned, as for non matches. A number of tests that were previously not
176        Perl-compatible have been moved into the Perl-compatible test files. The
177        refactoring has had the pleasing side effect of removing one argument from
178        the match() function, thus reducing its stack requirements.
179    
180    19. If the /S+ option was used in pcretest to study a pattern using JIT,
181        subsequent uses of /S (without +) incorrectly behaved like /S+.
182    
183    21. Retrieve executable code size support for the JIT compiler and fixing
184        some warnings.
185    
186    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
187        not work when the shorter character appeared right at the end of the
188        subject string.
189    
190    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
191        systems.
192    
193    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
194        output it when the /M option is used in pcretest.
195    
196    25. The CheckMan script was not being included in the distribution. Also, added
197        an explicit "perl" to run Perl scripts from the PrepareRelease script
198        because this is reportedly needed in Windows.
199    
200    26. If study data was being save in a file and studying had not found a set of
201        "starts with" bytes for the pattern, the data written to the file (though
202        never used) was taken from uninitialized memory and so caused valgrind to
203        complain.
204    
205    27. Updated RunTest.bat as provided by Sheri Pierce.
206    
207    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
208    
209    29. Computation of memory usage for the table of capturing group names was
210        giving an unnecessarily large value.
211    
212    
213    Version 8.20 21-Oct-2011
214  ------------------------  ------------------------
215    
216  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
217     a POSIX class. After further experiments with Perl, which convinced me that      a POSIX class. After further experiments with Perl, which convinced me that
218     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
219     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
220     with full stops.      with full stops.
221    
222  2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no captured  2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
223     substring, but while checking the failing first alternative, substring 1 is      captured substring, but while checking the failing first alternative,
224     temporarily captured. If the output vector supplied to pcre_exec() was not      substring 1 is temporarily captured. If the output vector supplied to
225     big enough for this capture, the yield of the function was still zero      pcre_exec() was not big enough for this capture, the yield of the function
226     ("insufficient space for captured substrings"). This cannot be totally fixed      was still zero ("insufficient space for captured substrings"). This cannot
227     without adding another stack variable, which seems a lot of expense for a      be totally fixed without adding another stack variable, which seems a lot
228     edge case. However, I have improved the situation in cases such as      of expense for a edge case. However, I have improved the situation in cases
229     /(a)(b)x|abc/ matched against "abc", where the return code indicates that      such as /(a)(b)x|abc/ matched against "abc", where the return code
230     fewer than the maximum number of slots in the ovector have been set.      indicates that fewer than the maximum number of slots in the ovector have
231        been set.
232  3. Related to (2) above: when there are more back references in a pattern than  
233     slots in the output vector, pcre_exec() uses temporary memory during  3.  Related to (2) above: when there are more back references in a pattern than
234     matching, and copies in the captures as far as possible afterwards. It was      slots in the output vector, pcre_exec() uses temporary memory during
235     using the entire output vector, but this conflicts with the specification      matching, and copies in the captures as far as possible afterwards. It was
236     that only 2/3 is used for passing back captured substrings. Now it uses only      using the entire output vector, but this conflicts with the specification
237     the first 2/3, for compatibility. This is, of course, another edge case.      that only 2/3 is used for passing back captured substrings. Now it uses
238        only the first 2/3, for compatibility. This is, of course, another edge
239  4. Zoltan Herczeg's just-in-time compiler support has been integrated into the      case.
240     main code base, and can be used by building with --enable-jit. When this is  
241     done, pcregrep automatically uses it unless --disable-pcregrep-jit or the  4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
242     runtime --no-jit option is given.      main code base, and can be used by building with --enable-jit. When this is
243        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
244  5. When the number of matches in a pcre_dfa_exec() run exactly filled the      runtime --no-jit option is given.
245     ovector, the return from the function was zero, implying that there were  
246     other matches that did not fit. The correct "exactly full" value is now  5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
247     returned.      ovector, the return from the function was zero, implying that there were
248        other matches that did not fit. The correct "exactly full" value is now
249  6. If a subpattern that was called recursively or as a subroutine contained      returned.
250     (*PRUNE) or any other control that caused it to give a non-standard return,  
251     invalid errors such as "Error -26 (nested recursion at the same subject  6.  If a subpattern that was called recursively or as a subroutine contained
252     position)" or even infinite loops could occur.      (*PRUNE) or any other control that caused it to give a non-standard return,
253        invalid errors such as "Error -26 (nested recursion at the same subject
254  7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped      position)" or even infinite loops could occur.
255     computing the minimum length on reaching *ACCEPT, and so ended up with the  
256     wrong value of 1 rather than 0. Further investigation indicates that  7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
257     computing a minimum subject length in the presence of *ACCEPT is difficult      computing the minimum length on reaching *ACCEPT, and so ended up with the
258     (think back references, subroutine calls), and so I have changed the code so      wrong value of 1 rather than 0. Further investigation indicates that
259     that no minimum is registered for a pattern that contains *ACCEPT.      computing a minimum subject length in the presence of *ACCEPT is difficult
260        (think back references, subroutine calls), and so I have changed the code
261  8. If (*THEN) was present in the first (true) branch of a conditional group,      so that no minimum is registered for a pattern that contains *ACCEPT.
262     it was not handled as intended.  
263    8.  If (*THEN) was present in the first (true) branch of a conditional group,
264        it was not handled as intended. [But see 16 below.]
265    
266    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
267        Sheri Pierce.
268    
269    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
270        the first byte in a match must be "a".
271    
272    11. Change 17 for 8.13 increased the recursion depth for patterns like
273        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
274        pattern contains any instances of (*THEN). If it does not, the old
275        optimizations are restored. It would be nice to do this on a per-group
276        basis, but at the moment that is not feasible.
277    
278    12. In some environments, the output of pcretest -C is CRLF terminated. This
279        broke RunTest's code that checks for the link size. A single white space
280        character after the value is now allowed for.
281    
282    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
283        For "fr", it uses the Windows-specific input and output files.
284    
285    14. If (*THEN) appeared in a group that was called recursively or as a
286        subroutine, it did not work as intended. [But see next item.]
287    
288    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
289        pattern fragments (but not containing any | characters). If A and B are
290        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
291        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
292        D. In other words, Perl considers parentheses that do not contain any |
293        characters to be part of a surrounding alternative, whereas PCRE was
294        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
295        differently. PCRE now behaves in the same way as Perl, except in the case
296        of subroutine/recursion calls such as (?1) which have in any case always
297        been different (but PCRE had them first :-).
298    
299    16. Related to 15 above: Perl does not treat the | in a conditional group as
300        creating alternatives. Such a group is treated in the same way as an
301        ordinary group without any | characters when processing (*THEN). PCRE has
302        been changed to match Perl's behaviour.
303    
304    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
305        RunGrepTest script failed.
306    
307    18. Change 22 for version 13 caused atomic groups to use more stack. This is
308        inevitable for groups that contain captures, but it can lead to a lot of
309        stack use in large patterns. The old behaviour has been restored for atomic
310        groups that do not contain any capturing parentheses.
311    
312    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
313        suppress the check for a minimum subject length at run time. (If it was
314        given to pcre_exec() or pcre_dfa_exec() it did work.)
315    
316    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
317        fail to work when decoding hex characters in data strings in EBCDIC
318        environments.
319    
320    21. It appears that in at least one Mac OS environment, the isxdigit() function
321        is implemented as a macro that evaluates to its argument more than once,
322        contravening the C 90 Standard (I haven't checked a later standard). There
323        was an instance in pcretest which caused it to go wrong when processing
324        \x{...} escapes in subject strings. The has been rewritten to avoid using
325        things like p++ in the argument of isxdigit().
326    
327    
328  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
# Line 150  Version 8.13 16-Aug-2011 Line 422  Version 8.13 16-Aug-2011
422      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
423      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
424      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
425      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
426    
427  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
428      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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