/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1320 by ph10, Wed May 1 16:39:35 2013 UTC revision 1459 by ph10, Tue Mar 4 10:45:15 2014 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.33 28-April-2013  Version 8.35-RC1 04-March-2014
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    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.
49    
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.
53    
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.
57    
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.
63    
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).
67    
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.
71    
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.
83    
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.
89    
90    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
91        was a bug in the test system, which is now fixed. Also, the list of various
92        configurations that are tested for each release did not have one with both
93        16/32 bits and --enable-bar-anycrlf. It now does.
94    
95    18. pcretest was missing "-C bsr" for displaying the \R default setting.
96    
97    19. Little endian PowerPC systems are supported now by the JIT compiler.
98    
99    20. The fast forward newline mechanism could enter to an infinite loop on
100        certain invalid UTF-8 input. Although we don't support these cases
101        this issue can be fixed by a performance optimization.
102    
103    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
104        not take account if existing stack usage. There is now a new global
105        variable called pcre_stack_guard that can be set to point to an external
106        function to check stack availability. It is called at the start of
107        processing every parenthesized group.
108    
109    
110    Version 8.34 15-December-2013
111    -----------------------------
112    
113    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
114        executable memory. Patch inspired by Carsten Klein.
115    
116    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
117        this macro is never tested and has no effect, because the work to support
118        coverage involves only compiling and linking options and special targets in
119        the Makefile. The comment in config.h implied that defining the macro would
120        enable coverage support, which is totally false. There was also support for
121        setting this macro in the CMake files (my fault, I just copied it from
122        configure). SUPPORT_GCOV has now been removed.
123    
124    3.  Make a small performance improvement in strlen16() and strlen32() in
125        pcretest.
126    
127    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
128        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
129        these cases). There was also one in pcretest.c.
130    
131    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
132    
133    6.  In UTF mode, the code for checking whether a group could match an empty
134        string (which is used for indefinitely repeated groups to allow for
135        breaking an infinite loop) was broken when the group contained a repeated
136        negated single-character class with a character that occupied more than one
137        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
138        UTF-8 mode). The effect was undefined: the group might or might not be
139        deemed as matching an empty string, or the program might have crashed.
140    
141    7.  The code for checking whether a group could match an empty string was not
142        recognizing that \h, \H, \v, \V, and \R must match a character.
143    
144    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
145        an empty string. If it can, pcretest shows this in its information output.
146    
147    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
148        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
149        matched by pcre_exec() without using JIT:
150    
151        (a) If the rest of the pattern did not match after a maximal run of
152            grapheme clusters, the code for backing up to try with fewer of them
153            did not always back up over a full grapheme when characters that do not
154            have the modifier quality were involved, e.g. Hangul syllables.
155    
156        (b) If the match point in a subject started with modifier character, and
157            there was no match, the code could incorrectly back up beyond the match
158            point, and potentially beyond the first character in the subject,
159            leading to a segfault or an incorrect match result.
160    
161    10. A conditional group with an assertion condition could lead to PCRE
162        recording an incorrect first data item for a match if no other first data
163        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
164        first data item, and therefore matched "ca" after "c" instead of at the
165        start.
166    
167    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
168        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
169    
170    12. The source of pcregrep now includes z/OS-specific code so that it can be
171        compiled for z/OS as part of the special z/OS distribution.
172    
173    13. Added the -T and -TM options to pcretest.
174    
175    14. The code in pcre_compile.c for creating the table of named capturing groups
176        has been refactored. Instead of creating the table dynamically during the
177        actual compiling pass, the information is remembered during the pre-compile
178        pass (on the stack unless there are more than 20 named groups, in which
179        case malloc() is used) and the whole table is created before the actual
180        compile happens. This has simplified the code (it is now nearly 150 lines
181        shorter) and prepared the way for better handling of references to groups
182        with duplicate names.
183    
184    15. A back reference to a named subpattern when there is more than one of the
185        same name now checks them in the order in which they appear in the pattern.
186        The first one that is set is used for the reference. Previously only the
187        first one was inspected. This change makes PCRE more compatible with Perl.
188    
189    16. Unicode character properties were updated from Unicode 6.3.0.
190    
191    17. The compile-time code for auto-possessification has been refactored, based
192        on a patch by Zoltan Herczeg. It now happens after instead of during
193        compilation. The code is cleaner, and more cases are handled. The option
194        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
195        options in pcretest are provided to set it. It can also be set by
196        (*NO_AUTO_POSSESS) at the start of a pattern.
197    
198    18. The character VT has been added to the default ("C" locale) set of
199        characters that match \s and are generally treated as white space,
200        following this same change in Perl 5.18. There is now no difference between
201        "Perl space" and "POSIX space". Whether VT is treated as white space in
202        other locales depends on the locale.
203    
204    19. The code for checking named groups as conditions, either for being set or
205        for being recursed, has been refactored (this is related to 14 and 15
206        above). Processing unduplicated named groups should now be as fast at
207        numerical groups, and processing duplicated groups should be faster than
208        before.
209    
210    20. Two patches to the CMake build system, by Alexander Barkov:
211    
212          (1) Replace the "source" command by "." in CMakeLists.txt because
213              "source" is a bash-ism.
214    
215          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
216              without these the CMake build does not work on Solaris.
217    
218    21. Perl has changed its handling of \8 and \9. If there is no previously
219        encountered capturing group of those numbers, they are treated as the
220        literal characters 8 and 9 instead of a binary zero followed by the
221        literals. PCRE now does the same.
222    
223    22. Following Perl, added \o{} to specify codepoints in octal, making it
224        possible to specify values greater than 0777 and also making them
225        unambiguous.
226    
227    23. Perl now gives an error for missing closing braces after \x{... instead of
228        treating the string as literal. PCRE now does the same.
229    
230    24. RunTest used to grumble if an inappropriate test was selected explicitly,
231        but just skip it when running all tests. This make it awkward to run ranges
232        of tests when one of them was inappropriate. Now it just skips any
233        inappropriate tests, as it always did when running all tests.
234    
235    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
236        character types such as \d or \w, too many callouts were inserted, and the
237        data that they returned was rubbish.
238    
239    26. In UCP mode, \s was not matching two of the characters that Perl matches,
240        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
241        were matched by \h. The code has now been refactored so that the lists of
242        the horizontal and vertical whitespace characters used for \h and \v (which
243        are defined only in one place) are now also used for \s.
244    
245    27. Add JIT support for the 64 bit TileGX architecture.
246        Patch by Jiong Wang (Tilera Corporation).
247    
248    28. Possessive quantifiers for classes (both explicit and automatically
249        generated) now use special opcodes instead of wrapping in ONCE brackets.
250    
251    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
252        (because it's meaningless), this was not happening when PCRE_CASELESS was
253        set. Not wrong, but inefficient.
254    
255    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
256        properties for \w, \d, etc) is present in a test regex. Otherwise if the
257        test contains no characters greater than 255, Perl doesn't realise it
258        should be using Unicode semantics.
259    
260    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
261        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
262        does in Unicode mode.
263    
264    32. Added the "forbid" facility to pcretest so that putting tests into the
265        wrong test files can sometimes be quickly detected.
266    
267    33. There is now a limit (default 250) on the depth of nesting of parentheses.
268        This limit is imposed to control the amount of system stack used at compile
269        time. It can be changed at build time by --with-parens-nest-limit=xxx or
270        the equivalent in CMake.
271    
272    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
273        errors. Perl warns for these when in warning mode, but PCRE has no facility
274        for giving warnings.
275    
276    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
277        However, this was not working for (?!) because it is optimized to (*FAIL),
278        for which PCRE does not allow quantifiers. The optimization is now disabled
279        when a quantifier follows (?!). I can't see any use for this, but it makes
280        things uniform.
281    
282    36. Perl no longer allows group names to start with digits, so I have made this
283        change also in PCRE. It simplifies the code a bit.
284    
285    37. In extended mode, Perl ignores spaces before a + that indicates a
286        possessive quantifier. PCRE allowed a space before the quantifier, but not
287        before the possessive +. It now does.
288    
289    38. The use of \K (reset reported match start) within a repeated possessive
290        group such as (a\Kb)*+ was not working.
291    
292    40. Document that the same character tables must be used at compile time and
293        run time, and that the facility to pass tables to pcre_exec() and
294        pcre_dfa_exec() is for use only with saved/restored patterns.
295    
296    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
297        features for Builds with MSVC:
298    
299        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
300           builds). The .rc files can be used to set FileDescription and many other
301           attributes.
302    
303        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
304           This allows higher-level build scripts which want .pdb files to avoid
305           hard-coding the exact files needed."
306    
307    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
308        mean "start of word" and "end of word", respectively, as a transition aid.
309    
310    43. A minimizing repeat of a class containing codepoints greater than 255 in
311        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
312        compiled to use the heap for recursion.
313    
314    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
315        is configured.
316    
317    
318    Version 8.33 28-May-2013
319    ------------------------
320    
321  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
322      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 350  Version 8.33 28-April-2013
350    
351  9.  Optimizing fast_forward_start_bits in JIT.  9.  Optimizing fast_forward_start_bits in JIT.
352    
353  10. Adding experimental support for callouts in JIT, and fixing some  10. Adding support for callouts in JIT, and fixing some issues revealed
354      issues revealed during this work. Namely:      during this work. Namely:
355    
356      (a) Unoptimized capturing brackets incorrectly reset on backtrack.      (a) Unoptimized capturing brackets incorrectly reset on backtrack.
357    
# Line 125  Version 8.33 28-April-2013 Line 439  Version 8.33 28-April-2013
439      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
440      these tests are now compatible.      these tests are now compatible.
441    
442  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
443        interpreter.
444    
445  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
446      contained a forward subroutine reference caused a compile error.      contained a forward subroutine reference caused a compile error.
# Line 145  Version 8.33 28-April-2013 Line 460  Version 8.33 28-April-2013
460      of the compiled pattern block, expand the flags field from 16 to 32 bits      of the compiled pattern block, expand the flags field from 16 to 32 bits
461      because it was almost full.      because it was almost full.
462    
463    39. Try madvise first before posix_madvise.
464    
465    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
466        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
467        original change locked out all matches of empty strings. This has been
468        changed so that one match of an empty string per line is recognized.
469        Subsequent searches on the same line (for colouring or for --only-matching,
470        for example) do not recognize empty strings.
471    
472    41. Applied a user patch to fix a number of spelling mistakes in comments.
473    
474    42. Data lines longer than 65536 caused pcretest to crash.
475    
476    43. Clarified the data type for length and startoffset arguments for pcre_exec
477        and pcre_dfa_exec in the function-specific man pages, where they were
478        explicitly stated to be in bytes, never having been updated. I also added
479        some clarification to the pcreapi man page.
480    
481    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
482        a segmentation fault.
483    
484    
485  Version 8.32 30-November-2012  Version 8.32 30-November-2012
486  -----------------------------  -----------------------------
# Line 1653  Version 7.9 11-Apr-09 Line 1989  Version 7.9 11-Apr-09
1989  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
1990      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
1991      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1992      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1993        8.33.]
1994    
1995  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
1996      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 1896  Version 7.7 07-May-08 Line 2233  Version 7.7 07-May-08
2233      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2234      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2235      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2236      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2237      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2238      was subsequently set up correctly.)      was subsequently set up correctly.)
2239    

Legend:
Removed from v.1320  
changed lines
  Added in v.1459

  ViewVC Help
Powered by ViewVC 1.1.5