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revision 1322 by zherczeg, Wed May 1 19:42:31 2013 UTC revision 1425 by ph10, Tue Dec 31 17:44:40 2013 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.33 28-April-2013  Version 8.35-RC1 xx-xxxx-201x
5  --------------------------  -----------------------------
6    
7    1.  A new flag is set, when property checks are present in an XCLASS.
8        When this flag is not set, PCRE can perform certain optimizations
9        such as studying these XCLASS-es.
10    
11    2.  The auto-possessification of character sets were improved: a normal
12        and an extended character set can be compared now. Furthermore
13        the JIT compiler optimizes more character set checks.
14    
15    3.  Got rid of some compiler warnings for potentially uninitialized variables
16        that show up only when compiled with -O2.
17    
18    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
19        of a match later then the end of the match. The pcretest program was not
20        handling the case sensibly - it was outputting from the start to the next
21        binary zero. It now reports this situation in a message, and outputs the
22        text from the end to the start.
23    
24    5.  Fast forward search is improved in JIT. Instead of the first three
25        characters, any three characters with fixed position can be searched.
26        Search order: first, last, middle.
27    
28    6.  Improve character range checks in JIT. Characters are read by an inprecise
29        function now, which returns with an unknown value if the character code is
30        above a certain treshold (e.g: 256). The only limitation is that the value
31        must be bigger than the treshold as well. This function is useful, when
32        the characters above the treshold are handled in the same way.
33    
34    7.  The macros RAWUCHAR and RAWUCHARTEST were identical (and the latter was not
35        testing anything, contrary to its name and comment) and were not really
36        fulfilling any useful function, so I have replaced their use by plain code.
37        Similarly for RAWUCHARINC and RAWUCHARINCTEST.
38    
39    
40    Version 8.34 15-December-2013
41    -----------------------------
42    
43    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
44        executable memory. Patch inspired by Carsten Klein.
45    
46    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
47        this macro is never tested and has no effect, because the work to support
48        coverage involves only compiling and linking options and special targets in
49        the Makefile. The comment in config.h implied that defining the macro would
50        enable coverage support, which is totally false. There was also support for
51        setting this macro in the CMake files (my fault, I just copied it from
52        configure). SUPPORT_GCOV has now been removed.
53    
54    3.  Make a small performance improvement in strlen16() and strlen32() in
55        pcretest.
56    
57    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
58        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
59        these cases). There was also one in pcretest.c.
60    
61    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
62    
63    6.  In UTF mode, the code for checking whether a group could match an empty
64        string (which is used for indefinitely repeated groups to allow for
65        breaking an infinite loop) was broken when the group contained a repeated
66        negated single-character class with a character that occupied more than one
67        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
68        UTF-8 mode). The effect was undefined: the group might or might not be
69        deemed as matching an empty string, or the program might have crashed.
70    
71    7.  The code for checking whether a group could match an empty string was not
72        recognizing that \h, \H, \v, \V, and \R must match a character.
73    
74    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
75        an empty string. If it can, pcretest shows this in its information output.
76    
77    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
78        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
79        matched by pcre_exec() without using JIT:
80    
81        (a) If the rest of the pattern did not match after a maximal run of
82            grapheme clusters, the code for backing up to try with fewer of them
83            did not always back up over a full grapheme when characters that do not
84            have the modifier quality were involved, e.g. Hangul syllables.
85    
86        (b) If the match point in a subject started with modifier character, and
87            there was no match, the code could incorrectly back up beyond the match
88            point, and potentially beyond the first character in the subject,
89            leading to a segfault or an incorrect match result.
90    
91    10. A conditional group with an assertion condition could lead to PCRE
92        recording an incorrect first data item for a match if no other first data
93        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
94        first data item, and therefore matched "ca" after "c" instead of at the
95        start.
96    
97    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
98        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
99    
100    12. The source of pcregrep now includes z/OS-specific code so that it can be
101        compiled for z/OS as part of the special z/OS distribution.
102    
103    13. Added the -T and -TM options to pcretest.
104    
105    14. The code in pcre_compile.c for creating the table of named capturing groups
106        has been refactored. Instead of creating the table dynamically during the
107        actual compiling pass, the information is remembered during the pre-compile
108        pass (on the stack unless there are more than 20 named groups, in which
109        case malloc() is used) and the whole table is created before the actual
110        compile happens. This has simplified the code (it is now nearly 150 lines
111        shorter) and prepared the way for better handling of references to groups
112        with duplicate names.
113    
114    15. A back reference to a named subpattern when there is more than one of the
115        same name now checks them in the order in which they appear in the pattern.
116        The first one that is set is used for the reference. Previously only the
117        first one was inspected. This change makes PCRE more compatible with Perl.
118    
119    16. Unicode character properties were updated from Unicode 6.3.0.
120    
121    17. The compile-time code for auto-possessification has been refactored, based
122        on a patch by Zoltan Herczeg. It now happens after instead of during
123        compilation. The code is cleaner, and more cases are handled. The option
124        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
125        options in pcretest are provided to set it. It can also be set by
126        (*NO_AUTO_POSSESS) at the start of a pattern.
127    
128    18. The character VT has been added to the default ("C" locale) set of
129        characters that match \s and are generally treated as white space,
130        following this same change in Perl 5.18. There is now no difference between
131        "Perl space" and "POSIX space". Whether VT is treated as white space in
132        other locales depends on the locale.
133    
134    19. The code for checking named groups as conditions, either for being set or
135        for being recursed, has been refactored (this is related to 14 and 15
136        above). Processing unduplicated named groups should now be as fast at
137        numerical groups, and processing duplicated groups should be faster than
138        before.
139    
140    20. Two patches to the CMake build system, by Alexander Barkov:
141    
142          (1) Replace the "source" command by "." in CMakeLists.txt because
143              "source" is a bash-ism.
144    
145          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
146              without these the CMake build does not work on Solaris.
147    
148    21. Perl has changed its handling of \8 and \9. If there is no previously
149        encountered capturing group of those numbers, they are treated as the
150        literal characters 8 and 9 instead of a binary zero followed by the
151        literals. PCRE now does the same.
152    
153    22. Following Perl, added \o{} to specify codepoints in octal, making it
154        possible to specify values greater than 0777 and also making them
155        unambiguous.
156    
157    23. Perl now gives an error for missing closing braces after \x{... instead of
158        treating the string as literal. PCRE now does the same.
159    
160    24. RunTest used to grumble if an inappropriate test was selected explicitly,
161        but just skip it when running all tests. This make it awkward to run ranges
162        of tests when one of them was inappropriate. Now it just skips any
163        inappropriate tests, as it always did when running all tests.
164    
165    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
166        character types such as \d or \w, too many callouts were inserted, and the
167        data that they returned was rubbish.
168    
169    26. In UCP mode, \s was not matching two of the characters that Perl matches,
170        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
171        were matched by \h. The code has now been refactored so that the lists of
172        the horizontal and vertical whitespace characters used for \h and \v (which
173        are defined only in one place) are now also used for \s.
174    
175    27. Add JIT support for the 64 bit TileGX architecture.
176        Patch by Jiong Wang (Tilera Corporation).
177    
178    28. Possessive quantifiers for classes (both explicit and automatically
179        generated) now use special opcodes instead of wrapping in ONCE brackets.
180    
181    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
182        (because it's meaningless), this was not happening when PCRE_CASELESS was
183        set. Not wrong, but inefficient.
184    
185    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
186        properties for \w, \d, etc) is present in a test regex. Otherwise if the
187        test contains no characters greater than 255, Perl doesn't realise it
188        should be using Unicode semantics.
189    
190    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
191        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
192        does in Unicode mode.
193    
194    32. Added the "forbid" facility to pcretest so that putting tests into the
195        wrong test files can sometimes be quickly detected.
196    
197    33. There is now a limit (default 250) on the depth of nesting of parentheses.
198        This limit is imposed to control the amount of system stack used at compile
199        time. It can be changed at build time by --with-parens-nest-limit=xxx or
200        the equivalent in CMake.
201    
202    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
203        errors. Perl warns for these when in warning mode, but PCRE has no facility
204        for giving warnings.
205    
206    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
207        However, this was not working for (?!) because it is optimized to (*FAIL),
208        for which PCRE does not allow quantifiers. The optimization is now disabled
209        when a quantifier follows (?!). I can't see any use for this, but it makes
210        things uniform.
211    
212    36. Perl no longer allows group names to start with digits, so I have made this
213        change also in PCRE. It simplifies the code a bit.
214    
215    37. In extended mode, Perl ignores spaces before a + that indicates a
216        possessive quantifier. PCRE allowed a space before the quantifier, but not
217        before the possessive +. It now does.
218    
219    38. The use of \K (reset reported match start) within a repeated possessive
220        group such as (a\Kb)*+ was not working.
221    
222    40. Document that the same character tables must be used at compile time and
223        run time, and that the facility to pass tables to pcre_exec() and
224        pcre_dfa_exec() is for use only with saved/restored patterns.
225    
226    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
227        features for Builds with MSVC:
228    
229        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
230           builds). The .rc files can be used to set FileDescription and many other
231           attributes.
232    
233        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
234           This allows higher-level build scripts which want .pdb files to avoid
235           hard-coding the exact files needed."
236    
237    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
238        mean "start of word" and "end of word", respectively, as a transition aid.
239    
240    43. A minimizing repeat of a class containing codepoints greater than 255 in
241        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
242        compiled to use the heap for recursion.
243    
244    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
245        is configured.
246    
247    
248    Version 8.33 28-May-2013
249    ------------------------
250    
251  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
252      avoid compiler signed/unsigned warnings. Added (int) casts to unsigned      avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
# Line 36  Version 8.33 28-April-2013 Line 280  Version 8.33 28-April-2013
280    
281  9.  Optimizing fast_forward_start_bits in JIT.  9.  Optimizing fast_forward_start_bits in JIT.
282    
283  10. Adding experimental support for callouts in JIT, and fixing some  10. Adding support for callouts in JIT, and fixing some issues revealed
284      issues revealed during this work. Namely:      during this work. Namely:
285    
286      (a) Unoptimized capturing brackets incorrectly reset on backtrack.      (a) Unoptimized capturing brackets incorrectly reset on backtrack.
287    
# Line 125  Version 8.33 28-April-2013 Line 369  Version 8.33 28-April-2013
369      have been moved to test 1, because either Perl or PCRE has changed, and      have been moved to test 1, because either Perl or PCRE has changed, and
370      these tests are now compatible.      these tests are now compatible.
371    
372  32. Control verbs are handled in the same way in JIT and interpreter.  32. Backtracking control verbs are now handled in the same way in JIT and
373        interpreter.
374    
375  33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that  33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
376      contained a forward subroutine reference caused a compile error.      contained a forward subroutine reference caused a compile error.
# Line 147  Version 8.33 28-April-2013 Line 392  Version 8.33 28-April-2013
392    
393  39. Try madvise first before posix_madvise.  39. Try madvise first before posix_madvise.
394    
395    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
396        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
397        original change locked out all matches of empty strings. This has been
398        changed so that one match of an empty string per line is recognized.
399        Subsequent searches on the same line (for colouring or for --only-matching,
400        for example) do not recognize empty strings.
401    
402    41. Applied a user patch to fix a number of spelling mistakes in comments.
403    
404    42. Data lines longer than 65536 caused pcretest to crash.
405    
406    43. Clarified the data type for length and startoffset arguments for pcre_exec
407        and pcre_dfa_exec in the function-specific man pages, where they were
408        explicitly stated to be in bytes, never having been updated. I also added
409        some clarification to the pcreapi man page.
410    
411    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
412        a segmentation fault.
413    
414    
415  Version 8.32 30-November-2012  Version 8.32 30-November-2012
416  -----------------------------  -----------------------------
# Line 1655  Version 7.9 11-Apr-09 Line 1919  Version 7.9 11-Apr-09
1919  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
1920      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
1921      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1922      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1923        8.33.]
1924    
1925  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
1926      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 1898  Version 7.7 07-May-08 Line 2163  Version 7.7 07-May-08
2163      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2164      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2165      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2166      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2167      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2168      was subsequently set up correctly.)      was subsequently set up correctly.)
2169    

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