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revision 1238 by ph10, Sat Jan 5 16:27:59 2013 UTC revision 1392 by ph10, Wed Nov 6 18:00:09 2013 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.33 xx-xxxx-201x  Version 8.34 xx-xxxx-201x
5  -------------------------  --------------------------
6    
7    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
8        executable memory. Patch inspired by Carsten Klein.
9    
10    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
11        this macro is never tested and has no effect, because the work to support
12        coverage involves only compiling and linking options and special targets in
13        the Makefile. The comment in config.h implied that defining the macro would
14        enable coverage support, which is totally false. There was also support for
15        setting this macro in the CMake files (my fault, I just copied it from
16        configure). SUPPORT_GCOV has now been removed.
17    
18    3.  Make a small performance improvement in strlen16() and strlen32() in
19        pcretest.
20    
21    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
22        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
23        these cases). There was also one in pcretest.c.
24    
25    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
26    
27    6.  In UTF mode, the code for checking whether a group could match an empty
28        string (which is used for indefinitely repeated groups to allow for
29        breaking an infinite loop) was broken when the group contained a repeated
30        negated single-character class with a character that occupied more than one
31        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
32        UTF-8 mode). The effect was undefined: the group might or might not be
33        deemed as matching an empty string, or the program might have crashed.
34    
35    7.  The code for checking whether a group could match an empty string was not
36        recognizing that \h, \H, \v, \V, and \R must match a character.
37    
38    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
39        an empty string. If it can, pcretest shows this in its information output.
40    
41    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
42        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
43        matched by pcre_exec() without using JIT:
44    
45        (a) If the rest of the pattern did not match after a maximal run of
46            grapheme clusters, the code for backing up to try with fewer of them
47            did not always back up over a full grapheme when characters that do not
48            have the modifier quality were involved, e.g. Hangul syllables.
49    
50        (b) If the match point in a subject started with modifier character, and
51            there was no match, the code could incorrectly back up beyond the match
52            point, and potentially beyond the first character in the subject,
53            leading to a segfault or an incorrect match result.
54    
55    10. A conditional group with an assertion condition could lead to PCRE
56        recording an incorrect first data item for a match if no other first data
57        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
58        first data item, and therefore matched "ca" after "c" instead of at the
59        start.
60    
61    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
62        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
63    
64    12. The source of pcregrep now includes z/OS-specific code so that it can be
65        compiled for z/OS as part of the special z/OS distribution.
66    
67    13. Added the -T and -TM options to pcretest.
68    
69    14. The code in pcre_compile.c for creating the table of named capturing groups
70        has been refactored. Instead of creating the table dynamically during the
71        actual compiling pass, the information is remembered during the pre-compile
72        pass (on the stack unless there are more than 20 named groups, in which
73        case malloc() is used) and the whole table is created before the actual
74        compile happens. This has simplified the code (it is now nearly 150 lines
75        shorter) and prepared the way for better handling of references to groups
76        with duplicate names.
77    
78    15. A back reference to a named subpattern when there is more than one of the
79        same name now checks them in the order in which they appear in the pattern.
80        The first one that is set is used for the reference. Previously only the
81        first one was inspected. This change makes PCRE more compatible with Perl.
82    
83    16. Unicode character properties were updated from Unicode 6.3.0.
84    
85    17. The compile-time code for auto-possessification has been refactored, based
86        on a patch by Zoltan Herczeg. It now happens after instead of during
87        compilation. The code is cleaner, and more cases are handled. The option
88        PCRE_NO_AUTO_POSSESSIFY is added for testing purposes, and the -O and /O
89        options in pcretest are provided to set it.
90    
91    18. The character VT has been added to the set of characters that match \s and
92        are generally treated as white space, following this same change in Perl
93        5.18. There is now no difference between "Perl space" and "POSIX space".
94    
95    19. The code for checking named groups as conditions, either for being set or
96        for being recursed, has been refactored (this is related to 14 and 15
97        above). Processing unduplicated named groups should now be as fast at
98        numerical groups, and processing duplicated groups should be faster than
99        before.
100    
101    20. Two patches to the CMake build system, by Alexander Barkov:
102    
103          (1) Replace the "source" command by "." in CMakeLists.txt because
104              "source" is a bash-ism.
105    
106          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
107              without these the CMake build does not work on Solaris.
108    
109    21. Perl has changed its handling of \8 and \9. If there is no previously
110        encountered capturing group of those numbers, they are treated as the
111        literal characters 8 and 9 instead of a binary zero followed by the
112        literals. PCRE now does the same.
113    
114    22. Following Perl, added \o{} to specify codepoints in octal, making it
115        possible to specify values greater than 0777 and also making them
116        unambiguous.
117    
118    23. Perl now gives an error for missing closing braces after \x{... instead of
119        treating the string as literal. PCRE now does the same.
120    
121    24. RunTest used to grumble if an inappropriate test was selected explicitly,
122        but just skip it when running all tests. This make it awkward to run ranges
123        of tests when one of them was inappropriate. Now it just skips any
124        inappropriate tests, as it always did when running all tests.
125    
126    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
127        character types such as \d or \w, too many callouts were inserted, and the
128        data that they returned was rubbish.
129    
130    26. In UCP mode, \s was not matching two of the characters that Perl matches,
131        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
132        were matched by \h. The code has now been refactored so that the lists of
133        the horizontal and vertical whitespace characters used for \h and \v (which
134        are defined only in one place) are now also used for \s.
135    
136    27. Add JIT support for the 64 bit TileGX architecture.
137        Patch by Jiong Wang (Tilera Corporation).
138    
139    28. Possessive quantifiers for classes (both explicit and automatically
140        generated) now use special opcodes instead of wrapping in ONCE brackets.
141    
142    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
143        (because it's meaningless), this was not happening when PCRE_CASELESS was
144        set. Not wrong, but inefficient.
145    
146    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
147        properties for \w, \d, etc) is present in a test regex. Otherwise if the
148        test contains no characters greater than 255, Perl doesn't realise it
149        should be using Unicode semantics.
150    
151    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
152        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
153        does in Unicode mode.
154    
155    32. Added the "forbid" facility to pcretest so that putting tests into the
156        wrong test files can sometimes be quickly detected.
157    
158    33. There is now a limit (default 250) on the depth of nesting of parentheses.
159        This limit is imposed to control the amount of system stack used at compile
160        time. It can be changed at build time by --with-parens-nest-limit=xxx or
161        the equivalent in CMake.
162    
163    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
164        errors. Perl warns for these when in warning mode, but PCRE has no facility
165        for giving warnings.
166    
167    
168    Version 8.33 28-May-2013
169    ------------------------
170    
171  1.  Added 'U' to some constants that are compared to unsigned integers, to  1.  Added 'U' to some constants that are compared to unsigned integers, to
172      avoid compiler signed/unsigned warnings. Added (int) casts to unsigned      avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
173      variables that are added to signed variables, to ensure the result is      variables that are added to signed variables, to ensure the result is
174      signed and can be negated.      signed and can be negated.
175    
176  2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the  2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
177      CMake config files.      CMake config files.
178    
179  3.  Revise the creation of config.h.generic so that all boolean macros are  3.  Revise the creation of config.h.generic so that all boolean macros are
180      #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes      #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
181      overriding via -D on the command line possible.      overriding via -D on the command line possible.
182    
183  4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar  4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
184      to unsigned int is reported to make a quite noticeable speed difference in      to unsigned int is reported to make a quite noticeable speed difference in
185      a specific Windows environment. Testing on Linux did also appear to show      a specific Windows environment. Testing on Linux did also appear to show
186      some benefit (and it is clearly not harmful). Also fixed the definition of      some benefit (and it is clearly not harmful). Also fixed the definition of
187      Xop which should be unsigned.      Xop which should be unsigned.
188    
189  5.  Related to (4), changing the definition of the intermediate variable cc  5.  Related to (4), changing the definition of the intermediate variable cc
190      in repeated character loops from pcre_uchar to pcre_uint32 also gave speed      in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
191      improvements.      improvements.
192    
193    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
194        unnecessary spaces.
195    
196    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
197        and later.
198    
199    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
200    
201    9.  Optimizing fast_forward_start_bits in JIT.
202    
203    10. Adding support for callouts in JIT, and fixing some issues revealed
204        during this work. Namely:
205    
206        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
207    
208        (b) Minimum length was not checked before the matching is started.
209    
210    11. The value of capture_last that is passed to callouts was incorrect in some
211        cases when there was a capture on one path that was subsequently abandoned
212        after a backtrack. Also, the capture_last value is now reset after a
213        recursion, since all captures are also reset in this case.
214    
215    12. The interpreter no longer returns the "too many substrings" error in the
216        case when an overflowing capture is in a branch that is subsequently
217        abandoned after a backtrack.
218    
219    13. In the pathological case when an offset vector of size 2 is used, pcretest
220        now prints out the matched string after a yield of 0 or 1.
221    
222    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
223        Only supported by the JIT compiler at the moment.
224    
225    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
226    
227    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
228        offset of the starting point of the matching process, provided the offsets
229        vector is large enough.
230    
231    17. The \A escape now records a lookbehind value of 1, though its execution
232        does not actually inspect the previous character. This is to ensure that,
233        in partial multi-segment matching, at least one character from the old
234        segment is retained when a new segment is processed. Otherwise, if there
235        are no lookbehinds in the pattern, \A might match incorrectly at the start
236        of a new segment.
237    
238    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
239    
240    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
241        gives some modest performance improvement in 8-bit mode.
242    
243    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
244        be expressed in certain programming languages using Universal Character
245        Names.
246    
247    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
248        which points out that "non characters" are not "characters that may not
249        appear in Unicode strings" but rather "characters that are reserved for
250        internal use and have only local meaning".
251    
252    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
253        there was a conditional group that depended on an assertion, if the
254        assertion was false, the callout that immediately followed the alternation
255        in the condition was skipped when pcre_exec() was used for matching.
256    
257    23. Allow an explicit callout to be inserted before an assertion that is the
258        condition for a conditional group, for compatibility with automatic
259        callouts, which always insert a callout at this point.
260    
261    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
262        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
263    
264    25. (*PRUNE) is now supported by the JIT compiler.
265    
266    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
267    
268    27. Fix the case where there are two or more SKIPs with arguments that may be
269        ignored.
270    
271    28. (*SKIP) is now supported by the JIT compiler.
272    
273    29. (*THEN) is now supported by the JIT compiler.
274    
275    30. Update RunTest with additional test selector options.
276    
277    31. The way PCRE handles backtracking verbs has been changed in two ways.
278    
279        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
280        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
281        backtracking. In some cases this makes it more Perl-compatible, but Perl's
282        rather obscure rules do not always do the same thing.
283    
284        (2) Previously, backtracking verbs were confined within assertions. This is
285        no longer the case for positive assertions, except for (*ACCEPT). Again,
286        this sometimes improves Perl compatibility, and sometimes does not.
287    
288    32. A number of tests that were in test 2 because Perl did things differently
289        have been moved to test 1, because either Perl or PCRE has changed, and
290        these tests are now compatible.
291    
292    32. Backtracking control verbs are now handled in the same way in JIT and
293        interpreter.
294    
295    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
296        contained a forward subroutine reference caused a compile error.
297    
298    34. Auto-detect and optimize limited repetitions in JIT.
299    
300    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
301        blocking (*UTF) etc.
302    
303    36. In the interpreter, maximizing pattern repetitions for characters and
304        character types now use tail recursion, which reduces stack usage.
305    
306    37. The value of the max lookbehind was not correctly preserved if a compiled
307        and saved regex was reloaded on a host of different endianness.
308    
309    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
310        of the compiled pattern block, expand the flags field from 16 to 32 bits
311        because it was almost full.
312    
313    39. Try madvise first before posix_madvise.
314    
315    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
316        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
317        original change locked out all matches of empty strings. This has been
318        changed so that one match of an empty string per line is recognized.
319        Subsequent searches on the same line (for colouring or for --only-matching,
320        for example) do not recognize empty strings.
321    
322    41. Applied a user patch to fix a number of spelling mistakes in comments.
323    
324    42. Data lines longer than 65536 caused pcretest to crash.
325    
326    43. Clarified the data type for length and startoffset arguments for pcre_exec
327        and pcre_dfa_exec in the function-specific man pages, where they were
328        explicitly stated to be in bytes, never having been updated. I also added
329        some clarification to the pcreapi man page.
330    
331    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
332        a segmentation fault.
333    
334    
335  Version 8.32 30-November-2012  Version 8.32 30-November-2012
336  -----------------------------  -----------------------------
# Line 1534  Version 7.9 11-Apr-09 Line 1839  Version 7.9 11-Apr-09
1839  7.  A pattern that could match an empty string could cause pcregrep to loop; it  7.  A pattern that could match an empty string could cause pcregrep to loop; it
1840      doesn't make sense to accept an empty string match in pcregrep, so I have      doesn't make sense to accept an empty string match in pcregrep, so I have
1841      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1842      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1843        8.33.]
1844    
1845  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at  8.  The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1846      start or after a newline", because the conditional assertion was not being      start or after a newline", because the conditional assertion was not being
# Line 1777  Version 7.7 07-May-08 Line 2083  Version 7.7 07-May-08
2083      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2084      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2085      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2086      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2087      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2088      was subsequently set up correctly.)      was subsequently set up correctly.)
2089    

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