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revision 1322 by zherczeg, Wed May 1 19:42:31 2013 UTC revision 1432 by ph10, Thu Jan 2 17:50:25 2014 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 whose names start with RAWUCHAR are placeholders for a future
35        mode in which only the bottom 21 bits of 32-bit data items are used. To
36        make this more memorable for those maintaining the code, the names have
37        been changed to start with UCHAR21, and an extensive comment has been added
38        to their definition.
39    
40    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
41        to the export list in Makefile.am (they were accidentally omitted from the
42        8.34 tarball).
43    
44    
45    Version 8.34 15-December-2013
46    -----------------------------
47    
48    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
49        executable memory. Patch inspired by Carsten Klein.
50    
51    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
52        this macro is never tested and has no effect, because the work to support
53        coverage involves only compiling and linking options and special targets in
54        the Makefile. The comment in config.h implied that defining the macro would
55        enable coverage support, which is totally false. There was also support for
56        setting this macro in the CMake files (my fault, I just copied it from
57        configure). SUPPORT_GCOV has now been removed.
58    
59    3.  Make a small performance improvement in strlen16() and strlen32() in
60        pcretest.
61    
62    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
63        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
64        these cases). There was also one in pcretest.c.
65    
66    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
67    
68    6.  In UTF mode, the code for checking whether a group could match an empty
69        string (which is used for indefinitely repeated groups to allow for
70        breaking an infinite loop) was broken when the group contained a repeated
71        negated single-character class with a character that occupied more than one
72        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
73        UTF-8 mode). The effect was undefined: the group might or might not be
74        deemed as matching an empty string, or the program might have crashed.
75    
76    7.  The code for checking whether a group could match an empty string was not
77        recognizing that \h, \H, \v, \V, and \R must match a character.
78    
79    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
80        an empty string. If it can, pcretest shows this in its information output.
81    
82    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
83        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
84        matched by pcre_exec() without using JIT:
85    
86        (a) If the rest of the pattern did not match after a maximal run of
87            grapheme clusters, the code for backing up to try with fewer of them
88            did not always back up over a full grapheme when characters that do not
89            have the modifier quality were involved, e.g. Hangul syllables.
90    
91        (b) If the match point in a subject started with modifier character, and
92            there was no match, the code could incorrectly back up beyond the match
93            point, and potentially beyond the first character in the subject,
94            leading to a segfault or an incorrect match result.
95    
96    10. A conditional group with an assertion condition could lead to PCRE
97        recording an incorrect first data item for a match if no other first data
98        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
99        first data item, and therefore matched "ca" after "c" instead of at the
100        start.
101    
102    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
103        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
104    
105    12. The source of pcregrep now includes z/OS-specific code so that it can be
106        compiled for z/OS as part of the special z/OS distribution.
107    
108    13. Added the -T and -TM options to pcretest.
109    
110    14. The code in pcre_compile.c for creating the table of named capturing groups
111        has been refactored. Instead of creating the table dynamically during the
112        actual compiling pass, the information is remembered during the pre-compile
113        pass (on the stack unless there are more than 20 named groups, in which
114        case malloc() is used) and the whole table is created before the actual
115        compile happens. This has simplified the code (it is now nearly 150 lines
116        shorter) and prepared the way for better handling of references to groups
117        with duplicate names.
118    
119    15. A back reference to a named subpattern when there is more than one of the
120        same name now checks them in the order in which they appear in the pattern.
121        The first one that is set is used for the reference. Previously only the
122        first one was inspected. This change makes PCRE more compatible with Perl.
123    
124    16. Unicode character properties were updated from Unicode 6.3.0.
125    
126    17. The compile-time code for auto-possessification has been refactored, based
127        on a patch by Zoltan Herczeg. It now happens after instead of during
128        compilation. The code is cleaner, and more cases are handled. The option
129        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
130        options in pcretest are provided to set it. It can also be set by
131        (*NO_AUTO_POSSESS) at the start of a pattern.
132    
133    18. The character VT has been added to the default ("C" locale) set of
134        characters that match \s and are generally treated as white space,
135        following this same change in Perl 5.18. There is now no difference between
136        "Perl space" and "POSIX space". Whether VT is treated as white space in
137        other locales depends on the locale.
138    
139    19. The code for checking named groups as conditions, either for being set or
140        for being recursed, has been refactored (this is related to 14 and 15
141        above). Processing unduplicated named groups should now be as fast at
142        numerical groups, and processing duplicated groups should be faster than
143        before.
144    
145    20. Two patches to the CMake build system, by Alexander Barkov:
146    
147          (1) Replace the "source" command by "." in CMakeLists.txt because
148              "source" is a bash-ism.
149    
150          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
151              without these the CMake build does not work on Solaris.
152    
153    21. Perl has changed its handling of \8 and \9. If there is no previously
154        encountered capturing group of those numbers, they are treated as the
155        literal characters 8 and 9 instead of a binary zero followed by the
156        literals. PCRE now does the same.
157    
158    22. Following Perl, added \o{} to specify codepoints in octal, making it
159        possible to specify values greater than 0777 and also making them
160        unambiguous.
161    
162    23. Perl now gives an error for missing closing braces after \x{... instead of
163        treating the string as literal. PCRE now does the same.
164    
165    24. RunTest used to grumble if an inappropriate test was selected explicitly,
166        but just skip it when running all tests. This make it awkward to run ranges
167        of tests when one of them was inappropriate. Now it just skips any
168        inappropriate tests, as it always did when running all tests.
169    
170    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
171        character types such as \d or \w, too many callouts were inserted, and the
172        data that they returned was rubbish.
173    
174    26. In UCP mode, \s was not matching two of the characters that Perl matches,
175        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
176        were matched by \h. The code has now been refactored so that the lists of
177        the horizontal and vertical whitespace characters used for \h and \v (which
178        are defined only in one place) are now also used for \s.
179    
180    27. Add JIT support for the 64 bit TileGX architecture.
181        Patch by Jiong Wang (Tilera Corporation).
182    
183    28. Possessive quantifiers for classes (both explicit and automatically
184        generated) now use special opcodes instead of wrapping in ONCE brackets.
185    
186    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
187        (because it's meaningless), this was not happening when PCRE_CASELESS was
188        set. Not wrong, but inefficient.
189    
190    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
191        properties for \w, \d, etc) is present in a test regex. Otherwise if the
192        test contains no characters greater than 255, Perl doesn't realise it
193        should be using Unicode semantics.
194    
195    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
196        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
197        does in Unicode mode.
198    
199    32. Added the "forbid" facility to pcretest so that putting tests into the
200        wrong test files can sometimes be quickly detected.
201    
202    33. There is now a limit (default 250) on the depth of nesting of parentheses.
203        This limit is imposed to control the amount of system stack used at compile
204        time. It can be changed at build time by --with-parens-nest-limit=xxx or
205        the equivalent in CMake.
206    
207    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
208        errors. Perl warns for these when in warning mode, but PCRE has no facility
209        for giving warnings.
210    
211    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
212        However, this was not working for (?!) because it is optimized to (*FAIL),
213        for which PCRE does not allow quantifiers. The optimization is now disabled
214        when a quantifier follows (?!). I can't see any use for this, but it makes
215        things uniform.
216    
217    36. Perl no longer allows group names to start with digits, so I have made this
218        change also in PCRE. It simplifies the code a bit.
219    
220    37. In extended mode, Perl ignores spaces before a + that indicates a
221        possessive quantifier. PCRE allowed a space before the quantifier, but not
222        before the possessive +. It now does.
223    
224    38. The use of \K (reset reported match start) within a repeated possessive
225        group such as (a\Kb)*+ was not working.
226    
227    40. Document that the same character tables must be used at compile time and
228        run time, and that the facility to pass tables to pcre_exec() and
229        pcre_dfa_exec() is for use only with saved/restored patterns.
230    
231    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
232        features for Builds with MSVC:
233    
234        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
235           builds). The .rc files can be used to set FileDescription and many other
236           attributes.
237    
238        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
239           This allows higher-level build scripts which want .pdb files to avoid
240           hard-coding the exact files needed."
241    
242    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
243        mean "start of word" and "end of word", respectively, as a transition aid.
244    
245    43. A minimizing repeat of a class containing codepoints greater than 255 in
246        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
247        compiled to use the heap for recursion.
248    
249    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
250        is configured.
251    
252    
253    Version 8.33 28-May-2013
254    ------------------------
255    
256  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
257      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 285  Version 8.33 28-April-2013
285    
286  9.  Optimizing fast_forward_start_bits in JIT.  9.  Optimizing fast_forward_start_bits in JIT.
287    
288  10. Adding experimental support for callouts in JIT, and fixing some  10. Adding support for callouts in JIT, and fixing some issues revealed
289      issues revealed during this work. Namely:      during this work. Namely:
290    
291      (a) Unoptimized capturing brackets incorrectly reset on backtrack.      (a) Unoptimized capturing brackets incorrectly reset on backtrack.
292    
# Line 125  Version 8.33 28-April-2013 Line 374  Version 8.33 28-April-2013
374      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
375      these tests are now compatible.      these tests are now compatible.
376    
377  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
378        interpreter.
379    
380  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
381      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 397  Version 8.33 28-April-2013
397    
398  39. Try madvise first before posix_madvise.  39. Try madvise first before posix_madvise.
399    
400    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
401        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
402        original change locked out all matches of empty strings. This has been
403        changed so that one match of an empty string per line is recognized.
404        Subsequent searches on the same line (for colouring or for --only-matching,
405        for example) do not recognize empty strings.
406    
407    41. Applied a user patch to fix a number of spelling mistakes in comments.
408    
409    42. Data lines longer than 65536 caused pcretest to crash.
410    
411    43. Clarified the data type for length and startoffset arguments for pcre_exec
412        and pcre_dfa_exec in the function-specific man pages, where they were
413        explicitly stated to be in bytes, never having been updated. I also added
414        some clarification to the pcreapi man page.
415    
416    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
417        a segmentation fault.
418    
419    
420  Version 8.32 30-November-2012  Version 8.32 30-November-2012
421  -----------------------------  -----------------------------
# Line 1655  Version 7.9 11-Apr-09 Line 1924  Version 7.9 11-Apr-09
1924  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
1925      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
1926      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1927      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1928        8.33.]
1929    
1930  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
1931      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 2168  Version 7.7 07-May-08
2168      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2169      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2170      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2171      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2172      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2173      was subsequently set up correctly.)      was subsequently set up correctly.)
2174    

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