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revision 1033 by ph10, Mon Sep 10 11:02:48 2012 UTC revision 1370 by ph10, Wed Oct 9 10:18:26 2013 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.32  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    
127    
128    Version 8.33 28-May-2013
129    ------------------------
130    
131    1.  Added 'U' to some constants that are compared to unsigned integers, to
132        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
133        variables that are added to signed variables, to ensure the result is
134        signed and can be negated.
135    
136    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
137        CMake config files.
138    
139    3.  Revise the creation of config.h.generic so that all boolean macros are
140        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
141        overriding via -D on the command line possible.
142    
143    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
144        to unsigned int is reported to make a quite noticeable speed difference in
145        a specific Windows environment. Testing on Linux did also appear to show
146        some benefit (and it is clearly not harmful). Also fixed the definition of
147        Xop which should be unsigned.
148    
149    5.  Related to (4), changing the definition of the intermediate variable cc
150        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
151        improvements.
152    
153    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
154        unnecessary spaces.
155    
156    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
157        and later.
158    
159    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
160    
161    9.  Optimizing fast_forward_start_bits in JIT.
162    
163    10. Adding support for callouts in JIT, and fixing some issues revealed
164        during this work. Namely:
165    
166        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
167    
168        (b) Minimum length was not checked before the matching is started.
169    
170    11. The value of capture_last that is passed to callouts was incorrect in some
171        cases when there was a capture on one path that was subsequently abandoned
172        after a backtrack. Also, the capture_last value is now reset after a
173        recursion, since all captures are also reset in this case.
174    
175    12. The interpreter no longer returns the "too many substrings" error in the
176        case when an overflowing capture is in a branch that is subsequently
177        abandoned after a backtrack.
178    
179    13. In the pathological case when an offset vector of size 2 is used, pcretest
180        now prints out the matched string after a yield of 0 or 1.
181    
182    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
183        Only supported by the JIT compiler at the moment.
184    
185    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
186    
187    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
188        offset of the starting point of the matching process, provided the offsets
189        vector is large enough.
190    
191    17. The \A escape now records a lookbehind value of 1, though its execution
192        does not actually inspect the previous character. This is to ensure that,
193        in partial multi-segment matching, at least one character from the old
194        segment is retained when a new segment is processed. Otherwise, if there
195        are no lookbehinds in the pattern, \A might match incorrectly at the start
196        of a new segment.
197    
198    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
199    
200    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
201        gives some modest performance improvement in 8-bit mode.
202    
203    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
204        be expressed in certain programming languages using Universal Character
205        Names.
206    
207    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
208        which points out that "non characters" are not "characters that may not
209        appear in Unicode strings" but rather "characters that are reserved for
210        internal use and have only local meaning".
211    
212    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
213        there was a conditional group that depended on an assertion, if the
214        assertion was false, the callout that immediately followed the alternation
215        in the condition was skipped when pcre_exec() was used for matching.
216    
217    23. Allow an explicit callout to be inserted before an assertion that is the
218        condition for a conditional group, for compatibility with automatic
219        callouts, which always insert a callout at this point.
220    
221    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
222        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
223    
224    25. (*PRUNE) is now supported by the JIT compiler.
225    
226    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
227    
228    27. Fix the case where there are two or more SKIPs with arguments that may be
229        ignored.
230    
231    28. (*SKIP) is now supported by the JIT compiler.
232    
233    29. (*THEN) is now supported by the JIT compiler.
234    
235    30. Update RunTest with additional test selector options.
236    
237    31. The way PCRE handles backtracking verbs has been changed in two ways.
238    
239        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
240        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
241        backtracking. In some cases this makes it more Perl-compatible, but Perl's
242        rather obscure rules do not always do the same thing.
243    
244        (2) Previously, backtracking verbs were confined within assertions. This is
245        no longer the case for positive assertions, except for (*ACCEPT). Again,
246        this sometimes improves Perl compatibility, and sometimes does not.
247    
248    32. A number of tests that were in test 2 because Perl did things differently
249        have been moved to test 1, because either Perl or PCRE has changed, and
250        these tests are now compatible.
251    
252    32. Backtracking control verbs are now handled in the same way in JIT and
253        interpreter.
254    
255    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
256        contained a forward subroutine reference caused a compile error.
257    
258    34. Auto-detect and optimize limited repetitions in JIT.
259    
260    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
261        blocking (*UTF) etc.
262    
263    36. In the interpreter, maximizing pattern repetitions for characters and
264        character types now use tail recursion, which reduces stack usage.
265    
266    37. The value of the max lookbehind was not correctly preserved if a compiled
267        and saved regex was reloaded on a host of different endianness.
268    
269    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
270        of the compiled pattern block, expand the flags field from 16 to 32 bits
271        because it was almost full.
272    
273    39. Try madvise first before posix_madvise.
274    
275    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
276        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
277        original change locked out all matches of empty strings. This has been
278        changed so that one match of an empty string per line is recognized.
279        Subsequent searches on the same line (for colouring or for --only-matching,
280        for example) do not recognize empty strings.
281    
282    41. Applied a user patch to fix a number of spelling mistakes in comments.
283    
284    42. Data lines longer than 65536 caused pcretest to crash.
285    
286    43. Clarified the data type for length and startoffset arguments for pcre_exec
287        and pcre_dfa_exec in the function-specific man pages, where they were
288        explicitly stated to be in bytes, never having been updated. I also added
289        some clarification to the pcreapi man page.
290    
291    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
292        a segmentation fault.
293    
294    
295    Version 8.32 30-November-2012
296    -----------------------------
297    
298  1.  Improved JIT compiler optimizations for first character search and single  1.  Improved JIT compiler optimizations for first character search and single
299      character iterators.      character iterators.
# Line 16  Version 8.32 Line 307  Version 8.32
307    
308  5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.  5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
309      Reported by Giuseppe D'Angelo.      Reported by Giuseppe D'Angelo.
310    
311  6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start  6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
312      of a line, was being set incorrectly in cases where .* appeared inside      of a line, was being set incorrectly in cases where .* appeared inside
313      atomic brackets at the start of a pattern, or where there was a subsequent      atomic brackets at the start of a pattern, or where there was a subsequent
314      *PRUNE or *SKIP.      *PRUNE or *SKIP.
315    
316  7.  Improved instruction cache flush for POWER/PowerPC.  7.  Improved instruction cache flush for POWER/PowerPC.
317      Patch by Daniel Richard G.      Patch by Daniel Richard G.
318    
319  8.  Fixed a number of issues in pcregrep, making it more compatible with GNU  8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
320      grep:      grep:
321    
322      (a) There is now no limit to the number of patterns to be matched.      (a) There is now no limit to the number of patterns to be matched.
323    
324      (b) An error is given if a pattern is too long.      (b) An error is given if a pattern is too long.
325    
326      (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir      (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
327          are now supported.          are now supported.
328    
329      (d) --exclude-from and --include-from (multiple use) have been added.      (d) --exclude-from and --include-from (multiple use) have been added.
330    
331      (e) Exclusions and inclusions now apply to all files and directories, not      (e) Exclusions and inclusions now apply to all files and directories, not
332          just to those obtained from scanning a directory recursively.          just to those obtained from scanning a directory recursively.
333    
334      (f) Multiple uses of -f and --file-list are now supported.      (f) Multiple uses of -f and --file-list are now supported.
335    
336      (g) In a Windows environment, the default for -d has been changed from      (g) In a Windows environment, the default for -d has been changed from
337          "read" (the GNU grep default) to "skip", because otherwise the presence          "read" (the GNU grep default) to "skip", because otherwise the presence
338          of a directory in the file list provokes an error.          of a directory in the file list provokes an error.
339    
340      (h) The documentation has been revised and clarified in places.      (h) The documentation has been revised and clarified in places.
341    
342  9.  Improve the matching speed of capturing brackets.  9.  Improve the matching speed of capturing brackets.
343    
344  10. Changed the meaning of \X so that it now matches a Unicode extended  10. Changed the meaning of \X so that it now matches a Unicode extended
345      grapheme cluster.      grapheme cluster.
346    
347  11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting  11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
348      out POSIX threads when JIT support is configured.      out POSIX threads when JIT support is configured.
349    
350  12. Added support for PCRE_STUDY_EXTRA_NEEDED.  12. Added support for PCRE_STUDY_EXTRA_NEEDED.
351    
352  13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg  13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
353      structure could go wrong in environments where size_t is not the same size      structure could go wrong in environments where size_t is not the same size
354      as int.      as int.
355    
356  14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be  14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
357      set.      set.
358    
359  15. The EBCDIC support had decayed; later updates to the code had included  15. The EBCDIC support had decayed; later updates to the code had included
360      explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a      explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
361      general tidy up of EBCDIC-related issues, and the documentation was also      general tidy up of EBCDIC-related issues, and the documentation was also
362      not quite right. There is now a test that can be run on ASCII systems to      not quite right. There is now a test that can be run on ASCII systems to
363      check some of the EBCDIC-related things (but is it not a full test).      check some of the EBCDIC-related things (but is it not a full test).
364    
365    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
366        in a small tidy to the code.
367    
368    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
369    
370    18. If the --only-matching (-o) option in pcregrep is specified multiple
371        times, each one causes appropriate output. For example, -o1 -o2 outputs the
372        substrings matched by the 1st and 2nd capturing parentheses. A separating
373        string can be specified by --om-separator (default empty).
374    
375    19. Improving the first n character searches.
376    
377    20. Turn case lists for horizontal and vertical white space into macros so that
378        they are defined only once.
379    
380    21. This set of changes together give more compatible Unicode case-folding
381        behaviour for characters that have more than one other case when UCP
382        support is available.
383    
384        (a) The Unicode property table now has offsets into a new table of sets of
385            three or more characters that are case-equivalent. The MultiStage2.py
386            script that generates these tables (the pcre_ucd.c file) now scans
387            CaseFolding.txt instead of UnicodeData.txt for character case
388            information.
389    
390        (b) The code for adding characters or ranges of characters to a character
391            class has been abstracted into a generalized function that also handles
392            case-independence. In UTF-mode with UCP support, this uses the new data
393            to handle characters with more than one other case.
394    
395        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
396            whose other case is greater than 256 are now correctly matched
397            caselessly. Previously, the high codepoint matched the low one, but not
398            vice versa.
399    
400        (d) The processing of \h, \H, \v, and \ in character classes now makes use
401            of the new class addition function, using character lists defined as
402            macros alongside the case definitions of 20 above.
403    
404        (e) Caseless back references now work with characters that have more than
405            one other case.
406    
407        (f) General caseless matching of characters with more than one other case
408            is supported.
409    
410    22. Unicode character properties were updated from Unicode 6.2.0
411    
412    23. Improved CMake support under Windows. Patch by Daniel Richard G.
413    
414    24. Add support for 32-bit character strings, and UTF-32
415    
416    25. Major JIT compiler update (code refactoring and bugfixing).
417        Experimental Sparc 32 support is added.
418    
419    26. Applied a modified version of Daniel Richard G's patch to create
420        pcre.h.generic and config.h.generic by "make" instead of in the
421        PrepareRelease script.
422    
423    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
424        pcre_compile.c when checking for a zero character.
425    
426    28. Introducing a native interface for JIT. Through this interface, the compiled
427        machine code can be directly executed. The purpose of this interface is to
428        provide fast pattern matching, so several sanity checks are not performed.
429        However, feature tests are still performed. The new interface provides
430        1.4x speedup compared to the old one.
431    
432    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
433        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
434        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
435    
436    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
437        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
438        the "old" RFC 2279). Instead, it ended up passing a negative length to
439        pcre_exec().
440    
441    31. Add support for GCC's visibility feature to hide internal functions.
442    
443    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
444        "unknown -C option" after outputting 0 or 1.
445    
446    33. There is now support for generating a code coverage report for the test
447        suite in environments where gcc is the compiler and lcov is installed. This
448        is mainly for the benefit of the developers.
449    
450    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
451        unaddressable using valgrind annotations, allowing valgrind to detect
452        invalid memory accesses. This is mainly for the benefit of the developers.
453    
454    25. (*UTF) can now be used to start a pattern in any of the three libraries.
455    
456    26. Give configure error if --enable-cpp but no C++ compiler found.
457    
458    
459  Version 8.31 06-July-2012  Version 8.31 06-July-2012
# Line 1416  Version 7.9 11-Apr-09 Line 1799  Version 7.9 11-Apr-09
1799  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
1800      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
1801      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1802      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1803        8.33.]
1804    
1805  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
1806      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 1659  Version 7.7 07-May-08 Line 2043  Version 7.7 07-May-08
2043      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2044      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2045      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2046      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2047      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2048      was subsequently set up correctly.)      was subsequently set up correctly.)
2049    

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