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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    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
37        running pcretest, the text "(JIT)" added to the output whenever JIT is
38        actually used to run the match.
39    
40    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
41        or /S+[+] with a digit between 1 and 7.
42    
43    8.  OP_NOT now supports any UTF character not just single-byte ones.
44    
45    9.  (*MARK) control verb is now supported by the JIT compiler.
46    
47    10. The command "./RunTest list" lists the available tests without actually
48        running any of them. (Because I keep forgetting what they all are.)
49    
50    11. Add PCRE_INFO_MAXLOOKBEHIND.
51    
52    12. Applied a (slightly modified) user-supplied patch that improves performance
53        when the heap is used for recursion (compiled with --disable-stack-for-
54        recursion). Instead of malloc and free for each heap frame each time a
55        logical recursion happens, frames are retained on a chain and re-used where
56        possible. This sometimes gives as much as 30% improvement.
57    
58    13. (*COMMIT) is now correctly confined to within a recursive subpattern call.
59    
60    
61    Version 8.30 04-February-2012
62    -----------------------------
63    
64    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
65        name is defined in ctype.h.
66    
67    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
68        only in quite long subpatterns.
69    
70    3.  Removed the function pcre_info(), which has been obsolete and deprecated
71        since it was replaced by pcre_fullinfo() in February 2000.
72    
73    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
74        match a (*MARK), and the match failed at the start of the subject, a
75        reference to memory before the start of the subject could occur. This bug
76        was introduced by fix 17 of release 8.21.
77    
78    5.  A reference to an unset group with zero minimum repetition was giving
79        totally wrong answers (in non-JavaScript-compatibility mode). For example,
80        /(another)?(\1?)test/ matched against "hello world test". This bug was
81        introduced in release 8.13.
82    
83    6.  Add support for 16-bit character strings (a large amount of work involving
84        many changes and refactorings).
85    
86    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
87        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
88        from a file.
89    
90    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
91        rounding is not applied in this particular case).
92    
93    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
94        if they appear, or are escaped, in patterns.
95    
96    10. Get rid of a number of -Wunused-but-set-variable warnings.
97    
98    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
99        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
100        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
101        also returns the mark "x". This bug applied to capturing parentheses,
102        non-capturing parentheses, and atomic parentheses. It also applied to some
103        assertions.
104    
105    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
106        information out of configure.ac instead of relying on pcre.h.generic, which
107        is not stored in the repository.
108    
109    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
110        -lreadline.
111    
112    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
113    
114    15. Applied Graycode's patch to put the top-level frame on the stack rather
115        than the heap when not using the stack for recursion. This gives a
116        performance improvement in many cases when recursion is not deep.
117    
118    16. Experimental code added to "pcretest -C" to output the stack frame size.
119    
120    
121    Version 8.21 12-Dec-2011
122    ------------------------
123    
124    1.  Updating the JIT compiler.
125    
126    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
127        are added as well.
128    
129    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
130        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
131        calling _pcre_jit_exec. Some extra comments are added.
132    
133    4.  (*MARK) settings inside atomic groups that do not contain any capturing
134        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
135        was introduced by change 18 for 8.20.
136    
137    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
138        ECMA-262 standard.
139    
140    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
141        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
142        This bug was probably introduced by change 9 of 8.13.
143    
144    7.  While fixing 6 above, I noticed that a number of other items were being
145        incorrectly rejected as "not fixed length". This arose partly because newer
146        opcodes had not been added to the fixed-length checking code. I have (a)
147        corrected the bug and added tests for these items, and (b) arranged for an
148        error to occur if an unknown opcode is encountered while checking for fixed
149        length instead of just assuming "not fixed length". The items that were
150        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
151        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
152        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
153    
154    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
155        being incorrectly compiled and would have given unpredicatble results.
156    
157    9.  A possessively repeated subpattern with minimum repeat count greater than
158        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
159        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
160        the first (A) could occur when it should not.
161    
162    10. Add a cast and remove a redundant test from the code.
163    
164    11. JIT should use pcre_malloc/pcre_free for allocation.
165    
166    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
167        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
168        is anything other than /usr, -L is still shown).
169    
170    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
171    
172    14. Perl does not support \N without a following name in a [] class; PCRE now
173        also gives an error.
174    
175    15. If a forward reference was repeated with an upper limit of around 2000,
176        it caused the error "internal error: overran compiling workspace". The
177        maximum number of forward references (including repeats) was limited by the
178        internal workspace, and dependent on the LINK_SIZE. The code has been
179        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
180        the default depends on LINK_SIZE. There is a new upper limit (for safety)
181        of around 200,000 forward references. While doing this, I also speeded up
182        the filling in of repeated forward references.
183    
184    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
185        incorrectly expecting the subject to contain another "a" after the start.
186    
187    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
188        in the match, the SKIP should be ignored. This was not happening; instead
189        the SKIP was being treated as NOMATCH. For patterns such as
190        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
191        tested.
192    
193    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
194        now much more compatible with Perl, in particular in cases where the result
195        is a non-match for a non-anchored pattern. For example, if
196        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
197        "m", where previously it did not return a name. A side effect of this
198        change is that for partial matches, the last encountered mark name is
199        returned, as for non matches. A number of tests that were previously not
200        Perl-compatible have been moved into the Perl-compatible test files. The
201        refactoring has had the pleasing side effect of removing one argument from
202        the match() function, thus reducing its stack requirements.
203    
204    19. If the /S+ option was used in pcretest to study a pattern using JIT,
205        subsequent uses of /S (without +) incorrectly behaved like /S+.
206    
207    21. Retrieve executable code size support for the JIT compiler and fixing
208        some warnings.
209    
210    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
211        not work when the shorter character appeared right at the end of the
212        subject string.
213    
214    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
215        systems.
216    
217    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
218        output it when the /M option is used in pcretest.
219    
220    25. The CheckMan script was not being included in the distribution. Also, added
221        an explicit "perl" to run Perl scripts from the PrepareRelease script
222        because this is reportedly needed in Windows.
223    
224    26. If study data was being save in a file and studying had not found a set of
225        "starts with" bytes for the pattern, the data written to the file (though
226        never used) was taken from uninitialized memory and so caused valgrind to
227        complain.
228    
229    27. Updated RunTest.bat as provided by Sheri Pierce.
230    
231    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
232    
233    29. Computation of memory usage for the table of capturing group names was
234        giving an unnecessarily large value.
235    
236    
237    Version 8.20 21-Oct-2011
238  ------------------------  ------------------------
239    
240  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
241     a POSIX class. After further experiments with Perl, which convinced me that      a POSIX class. After further experiments with Perl, which convinced me that
242     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
243     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
244     with full stops.      with full stops.
245    
246  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
247     substring, but while checking the failing first alternative, substring 1 is      captured substring, but while checking the failing first alternative,
248     temporarily captured. If the output vector supplied to pcre_exec() was not      substring 1 is temporarily captured. If the output vector supplied to
249     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
250     ("insufficient space for captured substrings"). This cannot be totally fixed      was still zero ("insufficient space for captured substrings"). This cannot
251     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
252     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
253     /(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
254     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
255        been set.
256  3. Related to (2) above: when there are more back references in a pattern than  
257     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
258     matching, and copies in the captures as far as possible afterwards. It was      slots in the output vector, pcre_exec() uses temporary memory during
259     using the entire output vector, but this conflicts with the specification      matching, and copies in the captures as far as possible afterwards. It was
260     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
261     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
262        only the first 2/3, for compatibility. This is, of course, another edge
263  4. Zoltan Herczeg's just-in-time compiler support has been integrated into the      case.
264     main code base, and can be used by building with --enable-jit. When this is  
265     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
266     runtime --no-jit option is given.      main code base, and can be used by building with --enable-jit. When this is
267        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
268  5. When the number of matches in a pcre_dfa_exec() run exactly filled the      runtime --no-jit option is given.
269     ovector, the return from the function was zero, implying that there were  
270     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
271     returned.      ovector, the return from the function was zero, implying that there were
272        other matches that did not fit. The correct "exactly full" value is now
273  6. If a subpattern that was called recursively or as a subroutine contained      returned.
274     (*PRUNE) or any other control that caused it to give a non-standard return,  
275     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
276     position)" or even infinite loops could occur.      (*PRUNE) or any other control that caused it to give a non-standard return,
277        invalid errors such as "Error -26 (nested recursion at the same subject
278  7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped      position)" or even infinite loops could occur.
279     computing the minimum length on reaching *ACCEPT, and so ended up with the  
280     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
281     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
282     (think back references, subroutine calls), and so I have changed the code so      wrong value of 1 rather than 0. Further investigation indicates that
283     that no minimum is registered for a pattern that contains *ACCEPT.      computing a minimum subject length in the presence of *ACCEPT is difficult
284        (think back references, subroutine calls), and so I have changed the code
285  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.
286     it was not handled as intended.  
287    8.  If (*THEN) was present in the first (true) branch of a conditional group,
288        it was not handled as intended. [But see 16 below.]
289    
290    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
291        Sheri Pierce.
292    
293    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
294        the first byte in a match must be "a".
295    
296    11. Change 17 for 8.13 increased the recursion depth for patterns like
297        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
298        pattern contains any instances of (*THEN). If it does not, the old
299        optimizations are restored. It would be nice to do this on a per-group
300        basis, but at the moment that is not feasible.
301    
302    12. In some environments, the output of pcretest -C is CRLF terminated. This
303        broke RunTest's code that checks for the link size. A single white space
304        character after the value is now allowed for.
305    
306    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
307        For "fr", it uses the Windows-specific input and output files.
308    
309    14. If (*THEN) appeared in a group that was called recursively or as a
310        subroutine, it did not work as intended. [But see next item.]
311    
312    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
313        pattern fragments (but not containing any | characters). If A and B are
314        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
315        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
316        D. In other words, Perl considers parentheses that do not contain any |
317        characters to be part of a surrounding alternative, whereas PCRE was
318        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
319        differently. PCRE now behaves in the same way as Perl, except in the case
320        of subroutine/recursion calls such as (?1) which have in any case always
321        been different (but PCRE had them first :-).
322    
323    16. Related to 15 above: Perl does not treat the | in a conditional group as
324        creating alternatives. Such a group is treated in the same way as an
325        ordinary group without any | characters when processing (*THEN). PCRE has
326        been changed to match Perl's behaviour.
327    
328    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
329        RunGrepTest script failed.
330    
331    18. Change 22 for version 13 caused atomic groups to use more stack. This is
332        inevitable for groups that contain captures, but it can lead to a lot of
333        stack use in large patterns. The old behaviour has been restored for atomic
334        groups that do not contain any capturing parentheses.
335    
336    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
337        suppress the check for a minimum subject length at run time. (If it was
338        given to pcre_exec() or pcre_dfa_exec() it did work.)
339    
340    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
341        fail to work when decoding hex characters in data strings in EBCDIC
342        environments.
343    
344    21. It appears that in at least one Mac OS environment, the isxdigit() function
345        is implemented as a macro that evaluates to its argument more than once,
346        contravening the C 90 Standard (I haven't checked a later standard). There
347        was an instance in pcretest which caused it to go wrong when processing
348        \x{...} escapes in subject strings. The has been rewritten to avoid using
349        things like p++ in the argument of isxdigit().
350    
351    
352  Version 8.13 16-Aug-2011  Version 8.13 16-Aug-2011
# Line 150  Version 8.13 16-Aug-2011 Line 446  Version 8.13 16-Aug-2011
446      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
447      the possibility of (*THEN) occurring in these branches, tail recursion is      the possibility of (*THEN) occurring in these branches, tail recursion is
448      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
449      two optimizations have therefore been removed.      two optimizations have therefore been removed. [But see 8.20/11 above.]
450    
451  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
452      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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