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revision 1322 by zherczeg, Wed May 1 19:42:31 2013 UTC revision 1449 by ph10, Fri Jan 17 16:59:52 2014 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.33 28-April-2013  Version 8.35-RC1 xx-xxxx-201x
5  --------------------------  -----------------------------
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.
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.
15    3.  Got rid of some compiler warnings for potentially uninitialized variables
16        that show up only when compiled with -O2.
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.
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.
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.
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.
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).
44    9.  The informational output from pcretest used the phrase "starting byte set"
45        which is inappropriate for the 16-bit and 32-bit libraries. As the output
46        for "first char" and "need char" really means "non-UTF-char", I've changed
47        "byte" to "char", and slightly reworded the output. The documentation about
48        these values has also been (I hope) clarified.
50    10. Another JIT related optimization: use table jumps for selecting the correct
51        backtracking path, when more than four alternatives are present inside a
52        bracket.
54    11. Empty match is not possible, when the minimum length is greater than zero,
55        and there is no \K in the pattern. JIT should avoid empty match checks in
56        such cases.
58    12. In a caseless character class with UCP support, when a character with more
59        than one alternative case was not the first character of a range, not all
60        the alternative cases were added to the class. For example, s and \x{17f}
61        are both alternative cases for S: the class [RST] was handled correctly,
62        but [R-T] was not.
64    13. The configure.ac file always checked for pthread support when JIT was
65        enabled. This is not used in Windows, so I have put this test inside a
66        check for the presence of windows.h (which was already tested for).
68    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
69        The algorithm provides a way to skip certain starting offsets, and usually
70        faster than linear prefix searches.
72    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
73        as for 'fr_FR' and 'french'. For some reason, however, it then used the
74        Windows-specific input and output files, which have 'french' screwed in.
75        So this could never have worked. One of the problems with locales is that
76        they aren't always the same. I have now updated RunTest so that it checks
77        the output of the locale test (test 3) against three different output
78        files, and it allows the test to pass if any one of them matches. With luck
79        this should make the test pass on some versions of Solaris where it was
80        failing. Because of the uncertainty, the script did not used to stop if
81        test 3 failed; it now does. If further versions of a French locale ever
82        come to light, they can now easily be added.
84    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
85        there was a message during ./configure, but it did not stop. This now
86        provokes an error. The invalid example in README has been corrected.
87        If a value less than the minimum is given, the minimum value has always
88        been used, but now a warning is given.
91    Version 8.34 15-December-2013
92    -----------------------------
94    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
95        executable memory. Patch inspired by Carsten Klein.
97    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
98        this macro is never tested and has no effect, because the work to support
99        coverage involves only compiling and linking options and special targets in
100        the Makefile. The comment in config.h implied that defining the macro would
101        enable coverage support, which is totally false. There was also support for
102        setting this macro in the CMake files (my fault, I just copied it from
103        configure). SUPPORT_GCOV has now been removed.
105    3.  Make a small performance improvement in strlen16() and strlen32() in
106        pcretest.
108    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
109        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
110        these cases). There was also one in pcretest.c.
112    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
114    6.  In UTF mode, the code for checking whether a group could match an empty
115        string (which is used for indefinitely repeated groups to allow for
116        breaking an infinite loop) was broken when the group contained a repeated
117        negated single-character class with a character that occupied more than one
118        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
119        UTF-8 mode). The effect was undefined: the group might or might not be
120        deemed as matching an empty string, or the program might have crashed.
122    7.  The code for checking whether a group could match an empty string was not
123        recognizing that \h, \H, \v, \V, and \R must match a character.
125    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
126        an empty string. If it can, pcretest shows this in its information output.
128    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
129        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
130        matched by pcre_exec() without using JIT:
132        (a) If the rest of the pattern did not match after a maximal run of
133            grapheme clusters, the code for backing up to try with fewer of them
134            did not always back up over a full grapheme when characters that do not
135            have the modifier quality were involved, e.g. Hangul syllables.
137        (b) If the match point in a subject started with modifier character, and
138            there was no match, the code could incorrectly back up beyond the match
139            point, and potentially beyond the first character in the subject,
140            leading to a segfault or an incorrect match result.
142    10. A conditional group with an assertion condition could lead to PCRE
143        recording an incorrect first data item for a match if no other first data
144        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
145        first data item, and therefore matched "ca" after "c" instead of at the
146        start.
148    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
149        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
151    12. The source of pcregrep now includes z/OS-specific code so that it can be
152        compiled for z/OS as part of the special z/OS distribution.
154    13. Added the -T and -TM options to pcretest.
156    14. The code in pcre_compile.c for creating the table of named capturing groups
157        has been refactored. Instead of creating the table dynamically during the
158        actual compiling pass, the information is remembered during the pre-compile
159        pass (on the stack unless there are more than 20 named groups, in which
160        case malloc() is used) and the whole table is created before the actual
161        compile happens. This has simplified the code (it is now nearly 150 lines
162        shorter) and prepared the way for better handling of references to groups
163        with duplicate names.
165    15. A back reference to a named subpattern when there is more than one of the
166        same name now checks them in the order in which they appear in the pattern.
167        The first one that is set is used for the reference. Previously only the
168        first one was inspected. This change makes PCRE more compatible with Perl.
170    16. Unicode character properties were updated from Unicode 6.3.0.
172    17. The compile-time code for auto-possessification has been refactored, based
173        on a patch by Zoltan Herczeg. It now happens after instead of during
174        compilation. The code is cleaner, and more cases are handled. The option
175        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
176        options in pcretest are provided to set it. It can also be set by
177        (*NO_AUTO_POSSESS) at the start of a pattern.
179    18. The character VT has been added to the default ("C" locale) set of
180        characters that match \s and are generally treated as white space,
181        following this same change in Perl 5.18. There is now no difference between
182        "Perl space" and "POSIX space". Whether VT is treated as white space in
183        other locales depends on the locale.
185    19. The code for checking named groups as conditions, either for being set or
186        for being recursed, has been refactored (this is related to 14 and 15
187        above). Processing unduplicated named groups should now be as fast at
188        numerical groups, and processing duplicated groups should be faster than
189        before.
191    20. Two patches to the CMake build system, by Alexander Barkov:
193          (1) Replace the "source" command by "." in CMakeLists.txt because
194              "source" is a bash-ism.
196          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
197              without these the CMake build does not work on Solaris.
199    21. Perl has changed its handling of \8 and \9. If there is no previously
200        encountered capturing group of those numbers, they are treated as the
201        literal characters 8 and 9 instead of a binary zero followed by the
202        literals. PCRE now does the same.
204    22. Following Perl, added \o{} to specify codepoints in octal, making it
205        possible to specify values greater than 0777 and also making them
206        unambiguous.
208    23. Perl now gives an error for missing closing braces after \x{... instead of
209        treating the string as literal. PCRE now does the same.
211    24. RunTest used to grumble if an inappropriate test was selected explicitly,
212        but just skip it when running all tests. This make it awkward to run ranges
213        of tests when one of them was inappropriate. Now it just skips any
214        inappropriate tests, as it always did when running all tests.
216    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
217        character types such as \d or \w, too many callouts were inserted, and the
218        data that they returned was rubbish.
220    26. In UCP mode, \s was not matching two of the characters that Perl matches,
221        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
222        were matched by \h. The code has now been refactored so that the lists of
223        the horizontal and vertical whitespace characters used for \h and \v (which
224        are defined only in one place) are now also used for \s.
226    27. Add JIT support for the 64 bit TileGX architecture.
227        Patch by Jiong Wang (Tilera Corporation).
229    28. Possessive quantifiers for classes (both explicit and automatically
230        generated) now use special opcodes instead of wrapping in ONCE brackets.
232    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
233        (because it's meaningless), this was not happening when PCRE_CASELESS was
234        set. Not wrong, but inefficient.
236    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
237        properties for \w, \d, etc) is present in a test regex. Otherwise if the
238        test contains no characters greater than 255, Perl doesn't realise it
239        should be using Unicode semantics.
241    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
242        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
243        does in Unicode mode.
245    32. Added the "forbid" facility to pcretest so that putting tests into the
246        wrong test files can sometimes be quickly detected.
248    33. There is now a limit (default 250) on the depth of nesting of parentheses.
249        This limit is imposed to control the amount of system stack used at compile
250        time. It can be changed at build time by --with-parens-nest-limit=xxx or
251        the equivalent in CMake.
253    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
254        errors. Perl warns for these when in warning mode, but PCRE has no facility
255        for giving warnings.
257    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
258        However, this was not working for (?!) because it is optimized to (*FAIL),
259        for which PCRE does not allow quantifiers. The optimization is now disabled
260        when a quantifier follows (?!). I can't see any use for this, but it makes
261        things uniform.
263    36. Perl no longer allows group names to start with digits, so I have made this
264        change also in PCRE. It simplifies the code a bit.
266    37. In extended mode, Perl ignores spaces before a + that indicates a
267        possessive quantifier. PCRE allowed a space before the quantifier, but not
268        before the possessive +. It now does.
270    38. The use of \K (reset reported match start) within a repeated possessive
271        group such as (a\Kb)*+ was not working.
273    40. Document that the same character tables must be used at compile time and
274        run time, and that the facility to pass tables to pcre_exec() and
275        pcre_dfa_exec() is for use only with saved/restored patterns.
277    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
278        features for Builds with MSVC:
280        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
281           builds). The .rc files can be used to set FileDescription and many other
282           attributes.
284        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
285           This allows higher-level build scripts which want .pdb files to avoid
286           hard-coding the exact files needed."
288    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
289        mean "start of word" and "end of word", respectively, as a transition aid.
291    43. A minimizing repeat of a class containing codepoints greater than 255 in
292        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
293        compiled to use the heap for recursion.
295    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
296        is configured.
299    Version 8.33 28-May-2013
300    ------------------------
302  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
303      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 331  Version 8.33 28-April-2013
332  9.  Optimizing fast_forward_start_bits in JIT.  9.  Optimizing fast_forward_start_bits in JIT.
334  10. Adding experimental support for callouts in JIT, and fixing some  10. Adding support for callouts in JIT, and fixing some issues revealed
335      issues revealed during this work. Namely:      during this work. Namely:
337      (a) Unoptimized capturing brackets incorrectly reset on backtrack.      (a) Unoptimized capturing brackets incorrectly reset on backtrack.
# Line 125  Version 8.33 28-April-2013 Line 420  Version 8.33 28-April-2013
420      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
421      these tests are now compatible.      these tests are now compatible.
423  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
424        interpreter.
426  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
427      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 443  Version 8.33 28-April-2013
444  39. Try madvise first before posix_madvise.  39. Try madvise first before posix_madvise.
446    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
447        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
448        original change locked out all matches of empty strings. This has been
449        changed so that one match of an empty string per line is recognized.
450        Subsequent searches on the same line (for colouring or for --only-matching,
451        for example) do not recognize empty strings.
453    41. Applied a user patch to fix a number of spelling mistakes in comments.
455    42. Data lines longer than 65536 caused pcretest to crash.
457    43. Clarified the data type for length and startoffset arguments for pcre_exec
458        and pcre_dfa_exec in the function-specific man pages, where they were
459        explicitly stated to be in bytes, never having been updated. I also added
460        some clarification to the pcreapi man page.
462    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
463        a segmentation fault.
466  Version 8.32 30-November-2012  Version 8.32 30-November-2012
467  -----------------------------  -----------------------------
# Line 1655  Version 7.9 11-Apr-09 Line 1970  Version 7.9 11-Apr-09
1970  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
1971      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
1972      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1973      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1974        8.33.]
1976  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
1977      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 2214  Version 7.7 07-May-08
2214      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2215      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2216      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2217      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2218      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2219      was subsequently set up correctly.)      was subsequently set up correctly.)

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