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revision 1022 by ph10, Tue Aug 28 12:28:15 2012 UTC revision 1357 by ph10, Tue Aug 27 15:49:16 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    
70    Version 8.33 28-May-2013
71    ------------------------
72    
73    1.  Added 'U' to some constants that are compared to unsigned integers, to
74        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
75        variables that are added to signed variables, to ensure the result is
76        signed and can be negated.
77    
78    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
79        CMake config files.
80    
81    3.  Revise the creation of config.h.generic so that all boolean macros are
82        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
83        overriding via -D on the command line possible.
84    
85    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
86        to unsigned int is reported to make a quite noticeable speed difference in
87        a specific Windows environment. Testing on Linux did also appear to show
88        some benefit (and it is clearly not harmful). Also fixed the definition of
89        Xop which should be unsigned.
90    
91    5.  Related to (4), changing the definition of the intermediate variable cc
92        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
93        improvements.
94    
95    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
96        unnecessary spaces.
97    
98    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
99        and later.
100    
101    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
102    
103    9.  Optimizing fast_forward_start_bits in JIT.
104    
105    10. Adding support for callouts in JIT, and fixing some issues revealed
106        during this work. Namely:
107    
108        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
109    
110        (b) Minimum length was not checked before the matching is started.
111    
112    11. The value of capture_last that is passed to callouts was incorrect in some
113        cases when there was a capture on one path that was subsequently abandoned
114        after a backtrack. Also, the capture_last value is now reset after a
115        recursion, since all captures are also reset in this case.
116    
117    12. The interpreter no longer returns the "too many substrings" error in the
118        case when an overflowing capture is in a branch that is subsequently
119        abandoned after a backtrack.
120    
121    13. In the pathological case when an offset vector of size 2 is used, pcretest
122        now prints out the matched string after a yield of 0 or 1.
123    
124    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
125        Only supported by the JIT compiler at the moment.
126    
127    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
128    
129    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
130        offset of the starting point of the matching process, provided the offsets
131        vector is large enough.
132    
133    17. The \A escape now records a lookbehind value of 1, though its execution
134        does not actually inspect the previous character. This is to ensure that,
135        in partial multi-segment matching, at least one character from the old
136        segment is retained when a new segment is processed. Otherwise, if there
137        are no lookbehinds in the pattern, \A might match incorrectly at the start
138        of a new segment.
139    
140    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
141    
142    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
143        gives some modest performance improvement in 8-bit mode.
144    
145    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
146        be expressed in certain programming languages using Universal Character
147        Names.
148    
149    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
150        which points out that "non characters" are not "characters that may not
151        appear in Unicode strings" but rather "characters that are reserved for
152        internal use and have only local meaning".
153    
154    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
155        there was a conditional group that depended on an assertion, if the
156        assertion was false, the callout that immediately followed the alternation
157        in the condition was skipped when pcre_exec() was used for matching.
158    
159    23. Allow an explicit callout to be inserted before an assertion that is the
160        condition for a conditional group, for compatibility with automatic
161        callouts, which always insert a callout at this point.
162    
163    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
164        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
165    
166    25. (*PRUNE) is now supported by the JIT compiler.
167    
168    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
169    
170    27. Fix the case where there are two or more SKIPs with arguments that may be
171        ignored.
172    
173    28. (*SKIP) is now supported by the JIT compiler.
174    
175    29. (*THEN) is now supported by the JIT compiler.
176    
177    30. Update RunTest with additional test selector options.
178    
179    31. The way PCRE handles backtracking verbs has been changed in two ways.
180    
181        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
182        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
183        backtracking. In some cases this makes it more Perl-compatible, but Perl's
184        rather obscure rules do not always do the same thing.
185    
186        (2) Previously, backtracking verbs were confined within assertions. This is
187        no longer the case for positive assertions, except for (*ACCEPT). Again,
188        this sometimes improves Perl compatibility, and sometimes does not.
189    
190    32. A number of tests that were in test 2 because Perl did things differently
191        have been moved to test 1, because either Perl or PCRE has changed, and
192        these tests are now compatible.
193    
194    32. Backtracking control verbs are now handled in the same way in JIT and
195        interpreter.
196    
197    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
198        contained a forward subroutine reference caused a compile error.
199    
200    34. Auto-detect and optimize limited repetitions in JIT.
201    
202    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
203        blocking (*UTF) etc.
204    
205    36. In the interpreter, maximizing pattern repetitions for characters and
206        character types now use tail recursion, which reduces stack usage.
207    
208    37. The value of the max lookbehind was not correctly preserved if a compiled
209        and saved regex was reloaded on a host of different endianness.
210    
211    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
212        of the compiled pattern block, expand the flags field from 16 to 32 bits
213        because it was almost full.
214    
215    39. Try madvise first before posix_madvise.
216    
217    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
218        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
219        original change locked out all matches of empty strings. This has been
220        changed so that one match of an empty string per line is recognized.
221        Subsequent searches on the same line (for colouring or for --only-matching,
222        for example) do not recognize empty strings.
223    
224    41. Applied a user patch to fix a number of spelling mistakes in comments.
225    
226    42. Data lines longer than 65536 caused pcretest to crash.
227    
228    43. Clarified the data type for length and startoffset arguments for pcre_exec
229        and pcre_dfa_exec in the function-specific man pages, where they were
230        explicitly stated to be in bytes, never having been updated. I also added
231        some clarification to the pcreapi man page.
232    
233    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
234        a segmentation fault.
235    
236    
237    Version 8.32 30-November-2012
238    -----------------------------
239    
240  1.  Improved JIT compiler optimizations for first character search and single  1.  Improved JIT compiler optimizations for first character search and single
241      character iterators.      character iterators.
# Line 16  Version 8.32 Line 249  Version 8.32
249    
250  5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.  5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
251      Reported by Giuseppe D'Angelo.      Reported by Giuseppe D'Angelo.
252    
253  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
254      of a line, was being set incorrectly in cases where .* appeared inside      of a line, was being set incorrectly in cases where .* appeared inside
255      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
256      *PRUNE or *SKIP.      *PRUNE or *SKIP.
257    
258  7.  Improved instruction cache flush for POWER/PowerPC.  7.  Improved instruction cache flush for POWER/PowerPC.
259      Patch by Daniel Richard G.      Patch by Daniel Richard G.
260    
261  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
262      grep:      grep:
263    
264      (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.
265    
266      (b) An error is given if a pattern is too long.      (b) An error is given if a pattern is too long.
267    
268      (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir      (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
269          are now supported.          are now supported.
270    
271      (d) --exclude-from and --include-from (multiple use) have been added.      (d) --exclude-from and --include-from (multiple use) have been added.
272    
273      (e) Exclusions and inclusions now apply to all files and directories, not      (e) Exclusions and inclusions now apply to all files and directories, not
274          just to those obtained from scanning a directory recursively.          just to those obtained from scanning a directory recursively.
275    
276      (f) Multiple uses of -f and --file-list are now supported.      (f) Multiple uses of -f and --file-list are now supported.
277    
278      (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
279          "read" (the GNU grep default) to "skip", because otherwise the presence          "read" (the GNU grep default) to "skip", because otherwise the presence
280          of a directory in the file list provokes an error.          of a directory in the file list provokes an error.
281    
282      (h) The documentation has been revised and clarified in places.      (h) The documentation has been revised and clarified in places.
283    
284  9.  Improve the matching speed of capturing brackets.  9.  Improve the matching speed of capturing brackets.
285    
286  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
287      grapheme cluster.      grapheme cluster.
288    
289  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
290      out POSIX threads when JIT support is configured.      out POSIX threads when JIT support is configured.
291    
292  12. Added support for PCRE_STUDY_EXTRA_NEEDED.  12. Added support for PCRE_STUDY_EXTRA_NEEDED.
293    
294    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
295        structure could go wrong in environments where size_t is not the same size
296        as int.
297    
298    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
299        set.
300    
301    15. The EBCDIC support had decayed; later updates to the code had included
302        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
303        general tidy up of EBCDIC-related issues, and the documentation was also
304        not quite right. There is now a test that can be run on ASCII systems to
305        check some of the EBCDIC-related things (but is it not a full test).
306    
307    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
308        in a small tidy to the code.
309    
310    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
311    
312    18. If the --only-matching (-o) option in pcregrep is specified multiple
313        times, each one causes appropriate output. For example, -o1 -o2 outputs the
314        substrings matched by the 1st and 2nd capturing parentheses. A separating
315        string can be specified by --om-separator (default empty).
316    
317    19. Improving the first n character searches.
318    
319    20. Turn case lists for horizontal and vertical white space into macros so that
320        they are defined only once.
321    
322    21. This set of changes together give more compatible Unicode case-folding
323        behaviour for characters that have more than one other case when UCP
324        support is available.
325    
326        (a) The Unicode property table now has offsets into a new table of sets of
327            three or more characters that are case-equivalent. The MultiStage2.py
328            script that generates these tables (the pcre_ucd.c file) now scans
329            CaseFolding.txt instead of UnicodeData.txt for character case
330            information.
331    
332        (b) The code for adding characters or ranges of characters to a character
333            class has been abstracted into a generalized function that also handles
334            case-independence. In UTF-mode with UCP support, this uses the new data
335            to handle characters with more than one other case.
336    
337        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
338            whose other case is greater than 256 are now correctly matched
339            caselessly. Previously, the high codepoint matched the low one, but not
340            vice versa.
341    
342        (d) The processing of \h, \H, \v, and \ in character classes now makes use
343            of the new class addition function, using character lists defined as
344            macros alongside the case definitions of 20 above.
345    
346        (e) Caseless back references now work with characters that have more than
347            one other case.
348    
349        (f) General caseless matching of characters with more than one other case
350            is supported.
351    
352    22. Unicode character properties were updated from Unicode 6.2.0
353    
354    23. Improved CMake support under Windows. Patch by Daniel Richard G.
355    
356    24. Add support for 32-bit character strings, and UTF-32
357    
358    25. Major JIT compiler update (code refactoring and bugfixing).
359        Experimental Sparc 32 support is added.
360    
361    26. Applied a modified version of Daniel Richard G's patch to create
362        pcre.h.generic and config.h.generic by "make" instead of in the
363        PrepareRelease script.
364    
365    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
366        pcre_compile.c when checking for a zero character.
367    
368    28. Introducing a native interface for JIT. Through this interface, the compiled
369        machine code can be directly executed. The purpose of this interface is to
370        provide fast pattern matching, so several sanity checks are not performed.
371        However, feature tests are still performed. The new interface provides
372        1.4x speedup compared to the old one.
373    
374    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
375        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
376        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
377    
378    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
379        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
380        the "old" RFC 2279). Instead, it ended up passing a negative length to
381        pcre_exec().
382    
383    31. Add support for GCC's visibility feature to hide internal functions.
384    
385    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
386        "unknown -C option" after outputting 0 or 1.
387    
388    33. There is now support for generating a code coverage report for the test
389        suite in environments where gcc is the compiler and lcov is installed. This
390        is mainly for the benefit of the developers.
391    
392    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
393        unaddressable using valgrind annotations, allowing valgrind to detect
394        invalid memory accesses. This is mainly for the benefit of the developers.
395    
396    25. (*UTF) can now be used to start a pattern in any of the three libraries.
397    
398    26. Give configure error if --enable-cpp but no C++ compiler found.
399    
400    
401  Version 8.31 06-July-2012  Version 8.31 06-July-2012
# Line 1403  Version 7.9 11-Apr-09 Line 1741  Version 7.9 11-Apr-09
1741  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
1742      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
1743      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1744      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
1745        8.33.]
1746    
1747  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
1748      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 1646  Version 7.7 07-May-08 Line 1985  Version 7.7 07-May-08
1985      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
1986      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
1987      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
1988      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
1989      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
1990      was subsequently set up correctly.)      was subsequently set up correctly.)
1991    

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