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

Diff of /code/trunk/ChangeLog

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

revision 608 by ph10, Sun Jun 12 16:25:55 2011 UTC revision 1488 by ph10, Wed Jun 18 18:38:00 2014 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.13 30-Apr-2011  Version 8.36 xx-xxx-2014
5    ------------------------
6    
7    1.  Got rid of some compiler warnings in the C++ modules that were shown up by
8        -Wmissing-field-initializers and -Wunused-parameter.
9    
10    2.  The tests for quantifiers being too big (greater than 65535) were being
11        applied after reading the number, and stupidly assuming that integer
12        overflow would give a negative number. The tests are now applied as the
13        numbers are read.
14    
15    3.  Tidy code in pcre_exec.c where two branches that used to be different are
16        now the same.
17    
18    4.  The JIT compiler did not generate match limit checks for certain
19        bracketed expressions with quantifiers. This may lead to exponential
20        backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
21        issue should be resolved now.
22    
23    5.  Fixed an issue, which occures when nested alternatives are optimized
24        with table jumps.
25    
26    6.  Inserted two casts and changed some ints to size_t in the light of some
27        reported 64-bit compiler warnings (Bugzilla 1477).
28    
29    7.  Fixed a bug concerned with zero-minimum possessive groups that could match
30        an empty string, which sometimes were behaving incorrectly in the
31        interpreter (though correctly in the JIT matcher). This pcretest input is
32        an example:
33    
34          '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
35          NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
36    
37        the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
38        JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
39        for an empty string was breaking the inner loop and carrying on at a lower
40        level, when possessive repeated groups should always return to a higher
41        level as they have no backtrack points in them. The empty string test now
42        occurs at the outer level.
43    
44    8.  Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
45        ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
46    
47    9.  Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
48        doesn't).
49    
50    10. Change 8.34/15 introduced a bug that caused the amount of memory needed
51        to hold a pattern to be incorrectly computed (too small) when there were
52        named back references to duplicated names. This could cause "internal
53        error: code overflow" or "double free or corruption" or other memory
54        handling errors.
55    
56    11. When named subpatterns had the same prefixes, back references could be
57        confused. For example, in this pattern:
58    
59          /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
60    
61        the reference to 'Name' was incorrectly treated as a reference to a
62        duplicate name.
63    
64    12. A pattern such as /^s?c/mi8 where the optional character has more than
65        one "other case" was incorrectly compiled such that it would only try to
66        match starting at "c".
67    
68    13. When a pattern starting with \s was studied, VT was not included in the
69        list of possible starting characters; this should have been part of the
70        8.34/18 patch.
71    
72    14. If a character class started [\Qx]... where x is any character, the class
73        was incorrectly terminated at the ].
74    
75    15. If a pattern that started with a caseless match for a character with more
76        than one "other case" was studied, PCRE did not set up the starting code
77        unit bit map for the list of possible characters. Now it does. This is an
78        optimization improvement, not a bug fix.
79    
80    
81    Version 8.35 04-April-2014
82    --------------------------
83    
84    1.  A new flag is set, when property checks are present in an XCLASS.
85        When this flag is not set, PCRE can perform certain optimizations
86        such as studying these XCLASS-es.
87    
88    2.  The auto-possessification of character sets were improved: a normal
89        and an extended character set can be compared now. Furthermore
90        the JIT compiler optimizes more character set checks.
91    
92    3.  Got rid of some compiler warnings for potentially uninitialized variables
93        that show up only when compiled with -O2.
94    
95    4.  A pattern such as (?=ab\K) that uses \K in an assertion can set the start
96        of a match later then the end of the match. The pcretest program was not
97        handling the case sensibly - it was outputting from the start to the next
98        binary zero. It now reports this situation in a message, and outputs the
99        text from the end to the start.
100    
101    5.  Fast forward search is improved in JIT. Instead of the first three
102        characters, any three characters with fixed position can be searched.
103        Search order: first, last, middle.
104    
105    6.  Improve character range checks in JIT. Characters are read by an inprecise
106        function now, which returns with an unknown value if the character code is
107        above a certain treshold (e.g: 256). The only limitation is that the value
108        must be bigger than the treshold as well. This function is useful, when
109        the characters above the treshold are handled in the same way.
110    
111    7.  The macros whose names start with RAWUCHAR are placeholders for a future
112        mode in which only the bottom 21 bits of 32-bit data items are used. To
113        make this more memorable for those maintaining the code, the names have
114        been changed to start with UCHAR21, and an extensive comment has been added
115        to their definition.
116    
117    8.  Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
118        to the export list in Makefile.am (they were accidentally omitted from the
119        8.34 tarball).
120    
121    9.  The informational output from pcretest used the phrase "starting byte set"
122        which is inappropriate for the 16-bit and 32-bit libraries. As the output
123        for "first char" and "need char" really means "non-UTF-char", I've changed
124        "byte" to "char", and slightly reworded the output. The documentation about
125        these values has also been (I hope) clarified.
126    
127    10. Another JIT related optimization: use table jumps for selecting the correct
128        backtracking path, when more than four alternatives are present inside a
129        bracket.
130    
131    11. Empty match is not possible, when the minimum length is greater than zero,
132        and there is no \K in the pattern. JIT should avoid empty match checks in
133        such cases.
134    
135    12. In a caseless character class with UCP support, when a character with more
136        than one alternative case was not the first character of a range, not all
137        the alternative cases were added to the class. For example, s and \x{17f}
138        are both alternative cases for S: the class [RST] was handled correctly,
139        but [R-T] was not.
140    
141    13. The configure.ac file always checked for pthread support when JIT was
142        enabled. This is not used in Windows, so I have put this test inside a
143        check for the presence of windows.h (which was already tested for).
144    
145    14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
146        The algorithm provides a way to skip certain starting offsets, and usually
147        faster than linear prefix searches.
148    
149    15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
150        as for 'fr_FR' and 'french'. For some reason, however, it then used the
151        Windows-specific input and output files, which have 'french' screwed in.
152        So this could never have worked. One of the problems with locales is that
153        they aren't always the same. I have now updated RunTest so that it checks
154        the output of the locale test (test 3) against three different output
155        files, and it allows the test to pass if any one of them matches. With luck
156        this should make the test pass on some versions of Solaris where it was
157        failing. Because of the uncertainty, the script did not used to stop if
158        test 3 failed; it now does. If further versions of a French locale ever
159        come to light, they can now easily be added.
160    
161    16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
162        there was a message during ./configure, but it did not stop. This now
163        provokes an error. The invalid example in README has been corrected.
164        If a value less than the minimum is given, the minimum value has always
165        been used, but now a warning is given.
166    
167    17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
168        was a bug in the test system, which is now fixed. Also, the list of various
169        configurations that are tested for each release did not have one with both
170        16/32 bits and --enable-bar-anycrlf. It now does.
171    
172    18. pcretest was missing "-C bsr" for displaying the \R default setting.
173    
174    19. Little endian PowerPC systems are supported now by the JIT compiler.
175    
176    20. The fast forward newline mechanism could enter to an infinite loop on
177        certain invalid UTF-8 input. Although we don't support these cases
178        this issue can be fixed by a performance optimization.
179    
180    21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
181        not take account if existing stack usage. There is now a new global
182        variable called pcre_stack_guard that can be set to point to an external
183        function to check stack availability. It is called at the start of
184        processing every parenthesized group.
185    
186    22. A typo in the code meant that in ungreedy mode the max/min qualifier
187        behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
188        not match "ab".
189    
190    23. When UTF was disabled, the JIT program reported some incorrect compile
191        errors. These messages are silenced now.
192    
193    24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
194        compiler.
195    
196    25. Change all the temporary files used in RunGrepTest to be different to those
197        used by RunTest so that the tests can be run simultaneously, for example by
198        "make -j check".
199    
200    
201    Version 8.34 15-December-2013
202    -----------------------------
203    
204    1.  Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
205        executable memory. Patch inspired by Carsten Klein.
206    
207    2.  ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
208        this macro is never tested and has no effect, because the work to support
209        coverage involves only compiling and linking options and special targets in
210        the Makefile. The comment in config.h implied that defining the macro would
211        enable coverage support, which is totally false. There was also support for
212        setting this macro in the CMake files (my fault, I just copied it from
213        configure). SUPPORT_GCOV has now been removed.
214    
215    3.  Make a small performance improvement in strlen16() and strlen32() in
216        pcretest.
217    
218    4.  Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
219        detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
220        these cases). There was also one in pcretest.c.
221    
222    5.  Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
223    
224    6.  In UTF mode, the code for checking whether a group could match an empty
225        string (which is used for indefinitely repeated groups to allow for
226        breaking an infinite loop) was broken when the group contained a repeated
227        negated single-character class with a character that occupied more than one
228        data item and had a minimum repetition of zero (for example, [^\x{100}]* in
229        UTF-8 mode). The effect was undefined: the group might or might not be
230        deemed as matching an empty string, or the program might have crashed.
231    
232    7.  The code for checking whether a group could match an empty string was not
233        recognizing that \h, \H, \v, \V, and \R must match a character.
234    
235    8.  Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
236        an empty string. If it can, pcretest shows this in its information output.
237    
238    9.  Fixed two related bugs that applied to Unicode extended grapheme clusters
239        that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
240        matched by pcre_exec() without using JIT:
241    
242        (a) If the rest of the pattern did not match after a maximal run of
243            grapheme clusters, the code for backing up to try with fewer of them
244            did not always back up over a full grapheme when characters that do not
245            have the modifier quality were involved, e.g. Hangul syllables.
246    
247        (b) If the match point in a subject started with modifier character, and
248            there was no match, the code could incorrectly back up beyond the match
249            point, and potentially beyond the first character in the subject,
250            leading to a segfault or an incorrect match result.
251    
252    10. A conditional group with an assertion condition could lead to PCRE
253        recording an incorrect first data item for a match if no other first data
254        item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
255        first data item, and therefore matched "ca" after "c" instead of at the
256        start.
257    
258    11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
259        bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
260    
261    12. The source of pcregrep now includes z/OS-specific code so that it can be
262        compiled for z/OS as part of the special z/OS distribution.
263    
264    13. Added the -T and -TM options to pcretest.
265    
266    14. The code in pcre_compile.c for creating the table of named capturing groups
267        has been refactored. Instead of creating the table dynamically during the
268        actual compiling pass, the information is remembered during the pre-compile
269        pass (on the stack unless there are more than 20 named groups, in which
270        case malloc() is used) and the whole table is created before the actual
271        compile happens. This has simplified the code (it is now nearly 150 lines
272        shorter) and prepared the way for better handling of references to groups
273        with duplicate names.
274    
275    15. A back reference to a named subpattern when there is more than one of the
276        same name now checks them in the order in which they appear in the pattern.
277        The first one that is set is used for the reference. Previously only the
278        first one was inspected. This change makes PCRE more compatible with Perl.
279    
280    16. Unicode character properties were updated from Unicode 6.3.0.
281    
282    17. The compile-time code for auto-possessification has been refactored, based
283        on a patch by Zoltan Herczeg. It now happens after instead of during
284        compilation. The code is cleaner, and more cases are handled. The option
285        PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
286        options in pcretest are provided to set it. It can also be set by
287        (*NO_AUTO_POSSESS) at the start of a pattern.
288    
289    18. The character VT has been added to the default ("C" locale) set of
290        characters that match \s and are generally treated as white space,
291        following this same change in Perl 5.18. There is now no difference between
292        "Perl space" and "POSIX space". Whether VT is treated as white space in
293        other locales depends on the locale.
294    
295    19. The code for checking named groups as conditions, either for being set or
296        for being recursed, has been refactored (this is related to 14 and 15
297        above). Processing unduplicated named groups should now be as fast at
298        numerical groups, and processing duplicated groups should be faster than
299        before.
300    
301    20. Two patches to the CMake build system, by Alexander Barkov:
302    
303          (1) Replace the "source" command by "." in CMakeLists.txt because
304              "source" is a bash-ism.
305    
306          (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
307              without these the CMake build does not work on Solaris.
308    
309    21. Perl has changed its handling of \8 and \9. If there is no previously
310        encountered capturing group of those numbers, they are treated as the
311        literal characters 8 and 9 instead of a binary zero followed by the
312        literals. PCRE now does the same.
313    
314    22. Following Perl, added \o{} to specify codepoints in octal, making it
315        possible to specify values greater than 0777 and also making them
316        unambiguous.
317    
318    23. Perl now gives an error for missing closing braces after \x{... instead of
319        treating the string as literal. PCRE now does the same.
320    
321    24. RunTest used to grumble if an inappropriate test was selected explicitly,
322        but just skip it when running all tests. This make it awkward to run ranges
323        of tests when one of them was inappropriate. Now it just skips any
324        inappropriate tests, as it always did when running all tests.
325    
326    25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
327        character types such as \d or \w, too many callouts were inserted, and the
328        data that they returned was rubbish.
329    
330    26. In UCP mode, \s was not matching two of the characters that Perl matches,
331        namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
332        were matched by \h. The code has now been refactored so that the lists of
333        the horizontal and vertical whitespace characters used for \h and \v (which
334        are defined only in one place) are now also used for \s.
335    
336    27. Add JIT support for the 64 bit TileGX architecture.
337        Patch by Jiong Wang (Tilera Corporation).
338    
339    28. Possessive quantifiers for classes (both explicit and automatically
340        generated) now use special opcodes instead of wrapping in ONCE brackets.
341    
342    29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
343        (because it's meaningless), this was not happening when PCRE_CASELESS was
344        set. Not wrong, but inefficient.
345    
346    30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
347        properties for \w, \d, etc) is present in a test regex. Otherwise if the
348        test contains no characters greater than 255, Perl doesn't realise it
349        should be using Unicode semantics.
350    
351    31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
352        [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
353        does in Unicode mode.
354    
355    32. Added the "forbid" facility to pcretest so that putting tests into the
356        wrong test files can sometimes be quickly detected.
357    
358    33. There is now a limit (default 250) on the depth of nesting of parentheses.
359        This limit is imposed to control the amount of system stack used at compile
360        time. It can be changed at build time by --with-parens-nest-limit=xxx or
361        the equivalent in CMake.
362    
363    34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
364        errors. Perl warns for these when in warning mode, but PCRE has no facility
365        for giving warnings.
366    
367    35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
368        However, this was not working for (?!) because it is optimized to (*FAIL),
369        for which PCRE does not allow quantifiers. The optimization is now disabled
370        when a quantifier follows (?!). I can't see any use for this, but it makes
371        things uniform.
372    
373    36. Perl no longer allows group names to start with digits, so I have made this
374        change also in PCRE. It simplifies the code a bit.
375    
376    37. In extended mode, Perl ignores spaces before a + that indicates a
377        possessive quantifier. PCRE allowed a space before the quantifier, but not
378        before the possessive +. It now does.
379    
380    38. The use of \K (reset reported match start) within a repeated possessive
381        group such as (a\Kb)*+ was not working.
382    
383    40. Document that the same character tables must be used at compile time and
384        run time, and that the facility to pass tables to pcre_exec() and
385        pcre_dfa_exec() is for use only with saved/restored patterns.
386    
387    41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
388        features for Builds with MSVC:
389    
390        1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
391           builds). The .rc files can be used to set FileDescription and many other
392           attributes.
393    
394        2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
395           This allows higher-level build scripts which want .pdb files to avoid
396           hard-coding the exact files needed."
397    
398    42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
399        mean "start of word" and "end of word", respectively, as a transition aid.
400    
401    43. A minimizing repeat of a class containing codepoints greater than 255 in
402        non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
403        compiled to use the heap for recursion.
404    
405    44. Got rid of some compiler warnings for unused variables when UTF but not UCP
406        is configured.
407    
408    
409    Version 8.33 28-May-2013
410    ------------------------
411    
412    1.  Added 'U' to some constants that are compared to unsigned integers, to
413        avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
414        variables that are added to signed variables, to ensure the result is
415        signed and can be negated.
416    
417    2.  Applied patch by Daniel Richard G for quashing MSVC warnings to the
418        CMake config files.
419    
420    3.  Revise the creation of config.h.generic so that all boolean macros are
421        #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
422        overriding via -D on the command line possible.
423    
424    4.  Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
425        to unsigned int is reported to make a quite noticeable speed difference in
426        a specific Windows environment. Testing on Linux did also appear to show
427        some benefit (and it is clearly not harmful). Also fixed the definition of
428        Xop which should be unsigned.
429    
430    5.  Related to (4), changing the definition of the intermediate variable cc
431        in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
432        improvements.
433    
434    6.  Fix forward search in JIT when link size is 3 or greater. Also removed some
435        unnecessary spaces.
436    
437    7.  Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
438        and later.
439    
440    8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
441    
442    9.  Optimizing fast_forward_start_bits in JIT.
443    
444    10. Adding support for callouts in JIT, and fixing some issues revealed
445        during this work. Namely:
446    
447        (a) Unoptimized capturing brackets incorrectly reset on backtrack.
448    
449        (b) Minimum length was not checked before the matching is started.
450    
451    11. The value of capture_last that is passed to callouts was incorrect in some
452        cases when there was a capture on one path that was subsequently abandoned
453        after a backtrack. Also, the capture_last value is now reset after a
454        recursion, since all captures are also reset in this case.
455    
456    12. The interpreter no longer returns the "too many substrings" error in the
457        case when an overflowing capture is in a branch that is subsequently
458        abandoned after a backtrack.
459    
460    13. In the pathological case when an offset vector of size 2 is used, pcretest
461        now prints out the matched string after a yield of 0 or 1.
462    
463    14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
464        Only supported by the JIT compiler at the moment.
465    
466    15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
467    
468    16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
469        offset of the starting point of the matching process, provided the offsets
470        vector is large enough.
471    
472    17. The \A escape now records a lookbehind value of 1, though its execution
473        does not actually inspect the previous character. This is to ensure that,
474        in partial multi-segment matching, at least one character from the old
475        segment is retained when a new segment is processed. Otherwise, if there
476        are no lookbehinds in the pattern, \A might match incorrectly at the start
477        of a new segment.
478    
479    18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
480    
481    19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
482        gives some modest performance improvement in 8-bit mode.
483    
484    20. Added the PCRE-specific property \p{Xuc} for matching characters that can
485        be expressed in certain programming languages using Universal Character
486        Names.
487    
488    21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
489        which points out that "non characters" are not "characters that may not
490        appear in Unicode strings" but rather "characters that are reserved for
491        internal use and have only local meaning".
492    
493    22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
494        there was a conditional group that depended on an assertion, if the
495        assertion was false, the callout that immediately followed the alternation
496        in the condition was skipped when pcre_exec() was used for matching.
497    
498    23. Allow an explicit callout to be inserted before an assertion that is the
499        condition for a conditional group, for compatibility with automatic
500        callouts, which always insert a callout at this point.
501    
502    24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
503        confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
504    
505    25. (*PRUNE) is now supported by the JIT compiler.
506    
507    26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
508    
509    27. Fix the case where there are two or more SKIPs with arguments that may be
510        ignored.
511    
512    28. (*SKIP) is now supported by the JIT compiler.
513    
514    29. (*THEN) is now supported by the JIT compiler.
515    
516    30. Update RunTest with additional test selector options.
517    
518    31. The way PCRE handles backtracking verbs has been changed in two ways.
519    
520        (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
521        SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
522        backtracking. In some cases this makes it more Perl-compatible, but Perl's
523        rather obscure rules do not always do the same thing.
524    
525        (2) Previously, backtracking verbs were confined within assertions. This is
526        no longer the case for positive assertions, except for (*ACCEPT). Again,
527        this sometimes improves Perl compatibility, and sometimes does not.
528    
529    32. A number of tests that were in test 2 because Perl did things differently
530        have been moved to test 1, because either Perl or PCRE has changed, and
531        these tests are now compatible.
532    
533    32. Backtracking control verbs are now handled in the same way in JIT and
534        interpreter.
535    
536    33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
537        contained a forward subroutine reference caused a compile error.
538    
539    34. Auto-detect and optimize limited repetitions in JIT.
540    
541    35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
542        blocking (*UTF) etc.
543    
544    36. In the interpreter, maximizing pattern repetitions for characters and
545        character types now use tail recursion, which reduces stack usage.
546    
547    37. The value of the max lookbehind was not correctly preserved if a compiled
548        and saved regex was reloaded on a host of different endianness.
549    
550    38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
551        of the compiled pattern block, expand the flags field from 16 to 32 bits
552        because it was almost full.
553    
554    39. Try madvise first before posix_madvise.
555    
556    40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
557        with a pattern such as ^$. It has taken 4 years for anybody to notice! The
558        original change locked out all matches of empty strings. This has been
559        changed so that one match of an empty string per line is recognized.
560        Subsequent searches on the same line (for colouring or for --only-matching,
561        for example) do not recognize empty strings.
562    
563    41. Applied a user patch to fix a number of spelling mistakes in comments.
564    
565    42. Data lines longer than 65536 caused pcretest to crash.
566    
567    43. Clarified the data type for length and startoffset arguments for pcre_exec
568        and pcre_dfa_exec in the function-specific man pages, where they were
569        explicitly stated to be in bytes, never having been updated. I also added
570        some clarification to the pcreapi man page.
571    
572    44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
573        a segmentation fault.
574    
575    
576    Version 8.32 30-November-2012
577    -----------------------------
578    
579    1.  Improved JIT compiler optimizations for first character search and single
580        character iterators.
581    
582    2.  Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
583        Patch by Daniel Richard G.
584    
585    3.  Single character iterator optimizations in the JIT compiler.
586    
587    4.  Improved JIT compiler optimizations for character ranges.
588    
589    5.  Rename the "leave" variable names to "quit" to improve WinCE compatibility.
590        Reported by Giuseppe D'Angelo.
591    
592    6.  The PCRE_STARTLINE bit, indicating that a match can occur only at the start
593        of a line, was being set incorrectly in cases where .* appeared inside
594        atomic brackets at the start of a pattern, or where there was a subsequent
595        *PRUNE or *SKIP.
596    
597    7.  Improved instruction cache flush for POWER/PowerPC.
598        Patch by Daniel Richard G.
599    
600    8.  Fixed a number of issues in pcregrep, making it more compatible with GNU
601        grep:
602    
603        (a) There is now no limit to the number of patterns to be matched.
604    
605        (b) An error is given if a pattern is too long.
606    
607        (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
608            are now supported.
609    
610        (d) --exclude-from and --include-from (multiple use) have been added.
611    
612        (e) Exclusions and inclusions now apply to all files and directories, not
613            just to those obtained from scanning a directory recursively.
614    
615        (f) Multiple uses of -f and --file-list are now supported.
616    
617        (g) In a Windows environment, the default for -d has been changed from
618            "read" (the GNU grep default) to "skip", because otherwise the presence
619            of a directory in the file list provokes an error.
620    
621        (h) The documentation has been revised and clarified in places.
622    
623    9.  Improve the matching speed of capturing brackets.
624    
625    10. Changed the meaning of \X so that it now matches a Unicode extended
626        grapheme cluster.
627    
628    11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
629        out POSIX threads when JIT support is configured.
630    
631    12. Added support for PCRE_STUDY_EXTRA_NEEDED.
632    
633    13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
634        structure could go wrong in environments where size_t is not the same size
635        as int.
636    
637    14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
638        set.
639    
640    15. The EBCDIC support had decayed; later updates to the code had included
641        explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
642        general tidy up of EBCDIC-related issues, and the documentation was also
643        not quite right. There is now a test that can be run on ASCII systems to
644        check some of the EBCDIC-related things (but is it not a full test).
645    
646    16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
647        in a small tidy to the code.
648    
649    17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
650    
651    18. If the --only-matching (-o) option in pcregrep is specified multiple
652        times, each one causes appropriate output. For example, -o1 -o2 outputs the
653        substrings matched by the 1st and 2nd capturing parentheses. A separating
654        string can be specified by --om-separator (default empty).
655    
656    19. Improving the first n character searches.
657    
658    20. Turn case lists for horizontal and vertical white space into macros so that
659        they are defined only once.
660    
661    21. This set of changes together give more compatible Unicode case-folding
662        behaviour for characters that have more than one other case when UCP
663        support is available.
664    
665        (a) The Unicode property table now has offsets into a new table of sets of
666            three or more characters that are case-equivalent. The MultiStage2.py
667            script that generates these tables (the pcre_ucd.c file) now scans
668            CaseFolding.txt instead of UnicodeData.txt for character case
669            information.
670    
671        (b) The code for adding characters or ranges of characters to a character
672            class has been abstracted into a generalized function that also handles
673            case-independence. In UTF-mode with UCP support, this uses the new data
674            to handle characters with more than one other case.
675    
676        (c) A bug that is fixed as a result of (b) is that codepoints less than 256
677            whose other case is greater than 256 are now correctly matched
678            caselessly. Previously, the high codepoint matched the low one, but not
679            vice versa.
680    
681        (d) The processing of \h, \H, \v, and \ in character classes now makes use
682            of the new class addition function, using character lists defined as
683            macros alongside the case definitions of 20 above.
684    
685        (e) Caseless back references now work with characters that have more than
686            one other case.
687    
688        (f) General caseless matching of characters with more than one other case
689            is supported.
690    
691    22. Unicode character properties were updated from Unicode 6.2.0
692    
693    23. Improved CMake support under Windows. Patch by Daniel Richard G.
694    
695    24. Add support for 32-bit character strings, and UTF-32
696    
697    25. Major JIT compiler update (code refactoring and bugfixing).
698        Experimental Sparc 32 support is added.
699    
700    26. Applied a modified version of Daniel Richard G's patch to create
701        pcre.h.generic and config.h.generic by "make" instead of in the
702        PrepareRelease script.
703    
704    27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
705        pcre_compile.c when checking for a zero character.
706    
707    28. Introducing a native interface for JIT. Through this interface, the compiled
708        machine code can be directly executed. The purpose of this interface is to
709        provide fast pattern matching, so several sanity checks are not performed.
710        However, feature tests are still performed. The new interface provides
711        1.4x speedup compared to the old one.
712    
713    29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
714        the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
715        was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
716    
717    30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
718        greater than 0x7fffffff (which cannot be represented in UTF-8, even under
719        the "old" RFC 2279). Instead, it ended up passing a negative length to
720        pcre_exec().
721    
722    31. Add support for GCC's visibility feature to hide internal functions.
723    
724    32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
725        "unknown -C option" after outputting 0 or 1.
726    
727    33. There is now support for generating a code coverage report for the test
728        suite in environments where gcc is the compiler and lcov is installed. This
729        is mainly for the benefit of the developers.
730    
731    34. If PCRE is built with --enable-valgrind, certain memory regions are marked
732        unaddressable using valgrind annotations, allowing valgrind to detect
733        invalid memory accesses. This is mainly for the benefit of the developers.
734    
735    25. (*UTF) can now be used to start a pattern in any of the three libraries.
736    
737    26. Give configure error if --enable-cpp but no C++ compiler found.
738    
739    
740    Version 8.31 06-July-2012
741    -------------------------
742    
743    1.  Fixing a wrong JIT test case and some compiler warnings.
744    
745    2.  Removed a bashism from the RunTest script.
746    
747    3.  Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
748        to unsigned type, result still unsigned" that was given by an MS compiler
749        on encountering the code "-sizeof(xxx)".
750    
751    4.  Partial matching support is added to the JIT compiler.
752    
753    5.  Fixed several bugs concerned with partial matching of items that consist
754        of more than one character:
755    
756        (a) /^(..)\1/ did not partially match "aba" because checking references was
757            done on an "all or nothing" basis. This also applied to repeated
758            references.
759    
760        (b) \R did not give a hard partial match if \r was found at the end of the
761            subject.
762    
763        (c) \X did not give a hard partial match after matching one or more
764            characters at the end of the subject.
765    
766        (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
767            a partial match for the string "\r".
768    
769        (e) When newline was set to CRLF, the metacharacter "." did not recognize
770            a partial match for a CR character at the end of the subject string.
771    
772    6.  If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
773        running pcretest, the text "(JIT)" added to the output whenever JIT is
774        actually used to run the match.
775    
776    7.  Individual JIT compile options can be set in pcretest by following -s+[+]
777        or /S+[+] with a digit between 1 and 7.
778    
779    8.  OP_NOT now supports any UTF character not just single-byte ones.
780    
781    9.  (*MARK) control verb is now supported by the JIT compiler.
782    
783    10. The command "./RunTest list" lists the available tests without actually
784        running any of them. (Because I keep forgetting what they all are.)
785    
786    11. Add PCRE_INFO_MAXLOOKBEHIND.
787    
788    12. Applied a (slightly modified) user-supplied patch that improves performance
789        when the heap is used for recursion (compiled with --disable-stack-for-
790        recursion). Instead of malloc and free for each heap frame each time a
791        logical recursion happens, frames are retained on a chain and re-used where
792        possible. This sometimes gives as much as 30% improvement.
793    
794    13. As documented, (*COMMIT) is now confined to within a recursive subpattern
795        call.
796    
797    14. As documented, (*COMMIT) is now confined to within a positive assertion.
798    
799    15. It is now possible to link pcretest with libedit as an alternative to
800        libreadline.
801    
802    16. (*COMMIT) control verb is now supported by the JIT compiler.
803    
804    17. The Unicode data tables have been updated to Unicode 6.1.0.
805    
806    18. Added --file-list option to pcregrep.
807    
808    19. Added binary file support to pcregrep, including the -a, --binary-files,
809        -I, and --text options.
810    
811    20. The madvise function is renamed for posix_madvise for QNX compatibility
812        reasons. Fixed by Giuseppe D'Angelo.
813    
814    21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
815    
816    22. Changed the option for creating symbolic links for 16-bit man pages from
817        -s to -sf so that re-installing does not cause issues.
818    
819    23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
820    
821    24. Fixed a very old bug in pcretest that caused errors with restarted DFA
822        matches in certain environments (the workspace was not being correctly
823        retained). Also added to pcre_dfa_exec() a simple plausibility check on
824        some of the workspace data at the beginning of a restart.
825    
826    25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
827        was not doing so when it should - probably a typo introduced by SVN 528
828        (change 8.10/14).
829    
830    26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
831        \w+ when the character tables indicated that \x{c4} was a word character.
832        There were several related cases, all because the tests for doing a table
833        lookup were testing for characters less than 127 instead of 255.
834    
835    27. If a pattern contains capturing parentheses that are not used in a match,
836        their slots in the ovector are set to -1. For those that are higher than
837        any matched groups, this happens at the end of processing. In the case when
838        there were back references that the ovector was too small to contain
839        (causing temporary malloc'd memory to be used during matching), and the
840        highest capturing number was not used, memory off the end of the ovector
841        was incorrectly being set to -1. (It was using the size of the temporary
842        memory instead of the true size.)
843    
844    28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
845        ovector size, it uses memory at the end of the block that it has got.
846    
847    29. Check for an overlong MARK name and give an error at compile time. The
848        limit is 255 for the 8-bit library and 65535 for the 16-bit library.
849    
850    30. JIT compiler update.
851    
852    31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
853        Rill for the patch.
854    
855    32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
856    
857    33. Variable renamings in the PCRE-JIT compiler. No functionality change.
858    
859    34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
860        SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
861        was enabled.
862    
863    35. Improve JIT code generation for greedy plus quantifier.
864    
865    36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
866        1 to "aa" instead of to an empty string. The bug affected repeated groups
867        that could potentially match an empty string.
868    
869    37. Optimizing single character iterators in JIT.
870    
871    38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
872        the same checks as \x{...} characters in non-JavaScript mode. Specifically,
873        codepoints that are too big for the mode are faulted, and in a UTF mode,
874        disallowed codepoints are also faulted.
875    
876    39. If PCRE was compiled with UTF support, in three places in the DFA
877        matcher there was code that should only have been obeyed in UTF mode, but
878        was being obeyed unconditionally. In 8-bit mode this could cause incorrect
879        processing when bytes with values greater than 127 were present. In 16-bit
880        mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
881        both cases the values are those that cannot be the first data item in a UTF
882        character. The three items that might have provoked this were recursions,
883        possessively repeated groups, and atomic groups.
884    
885    40. Ensure that libpcre is explicitly listed in the link commands for pcretest
886        and pcregrep, because some OS require shared objects to be explicitly
887        passed to ld, causing the link step to fail if they are not.
888    
889    41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
890        mode, patterns that started with \h* or \R* might be incorrectly matched.
891    
892    
893    Version 8.30 04-February-2012
894    -----------------------------
895    
896    1.  Renamed "isnumber" as "is_a_number" because in some Mac environments this
897        name is defined in ctype.h.
898    
899    2.  Fixed a bug in fixed-length calculation for lookbehinds that would show up
900        only in quite long subpatterns.
901    
902    3.  Removed the function pcre_info(), which has been obsolete and deprecated
903        since it was replaced by pcre_fullinfo() in February 2000.
904    
905    4.  For a non-anchored pattern, if (*SKIP) was given with a name that did not
906        match a (*MARK), and the match failed at the start of the subject, a
907        reference to memory before the start of the subject could occur. This bug
908        was introduced by fix 17 of release 8.21.
909    
910    5.  A reference to an unset group with zero minimum repetition was giving
911        totally wrong answers (in non-JavaScript-compatibility mode). For example,
912        /(another)?(\1?)test/ matched against "hello world test". This bug was
913        introduced in release 8.13.
914    
915    6.  Add support for 16-bit character strings (a large amount of work involving
916        many changes and refactorings).
917    
918    7.  RunGrepTest failed on msys because \r\n was replaced by whitespace when the
919        command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
920        from a file.
921    
922    8.  Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
923        rounding is not applied in this particular case).
924    
925    9.  The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
926        if they appear, or are escaped, in patterns.
927    
928    10. Get rid of a number of -Wunused-but-set-variable warnings.
929    
930    11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
931        "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
932        Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
933        also returns the mark "x". This bug applied to capturing parentheses,
934        non-capturing parentheses, and atomic parentheses. It also applied to some
935        assertions.
936    
937    12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
938        information out of configure.ac instead of relying on pcre.h.generic, which
939        is not stored in the repository.
940    
941    13. Applied Dmitry V. Levin's patch for a more portable method for linking with
942        -lreadline.
943    
944    14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
945    
946    15. Applied Graycode's patch to put the top-level frame on the stack rather
947        than the heap when not using the stack for recursion. This gives a
948        performance improvement in many cases when recursion is not deep.
949    
950    16. Experimental code added to "pcretest -C" to output the stack frame size.
951    
952    
953    Version 8.21 12-Dec-2011
954    ------------------------
955    
956    1.  Updating the JIT compiler.
957    
958    2.  JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
959        are added as well.
960    
961    3.  Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
962        PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
963        calling _pcre_jit_exec. Some extra comments are added.
964    
965    4.  (*MARK) settings inside atomic groups that do not contain any capturing
966        parentheses, for example, (?>a(*:m)), were not being passed out. This bug
967        was introduced by change 18 for 8.20.
968    
969    5.  Supporting of \x, \U and \u in JavaScript compatibility mode based on the
970        ECMA-262 standard.
971    
972    6.  Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
973        erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
974        This bug was probably introduced by change 9 of 8.13.
975    
976    7.  While fixing 6 above, I noticed that a number of other items were being
977        incorrectly rejected as "not fixed length". This arose partly because newer
978        opcodes had not been added to the fixed-length checking code. I have (a)
979        corrected the bug and added tests for these items, and (b) arranged for an
980        error to occur if an unknown opcode is encountered while checking for fixed
981        length instead of just assuming "not fixed length". The items that were
982        rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
983        (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
984        repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
985    
986    8.  A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
987        being incorrectly compiled and would have given unpredicatble results.
988    
989    9.  A possessively repeated subpattern with minimum repeat count greater than
990        one behaved incorrectly. For example, (A){2,}+ behaved as if it was
991        (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
992        the first (A) could occur when it should not.
993    
994    10. Add a cast and remove a redundant test from the code.
995    
996    11. JIT should use pcre_malloc/pcre_free for allocation.
997    
998    12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
999        best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1000        is anything other than /usr, -L is still shown).
1001    
1002    13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1003    
1004    14. Perl does not support \N without a following name in a [] class; PCRE now
1005        also gives an error.
1006    
1007    15. If a forward reference was repeated with an upper limit of around 2000,
1008        it caused the error "internal error: overran compiling workspace". The
1009        maximum number of forward references (including repeats) was limited by the
1010        internal workspace, and dependent on the LINK_SIZE. The code has been
1011        rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1012        the default depends on LINK_SIZE. There is a new upper limit (for safety)
1013        of around 200,000 forward references. While doing this, I also speeded up
1014        the filling in of repeated forward references.
1015    
1016    16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1017        incorrectly expecting the subject to contain another "a" after the start.
1018    
1019    17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1020        in the match, the SKIP should be ignored. This was not happening; instead
1021        the SKIP was being treated as NOMATCH. For patterns such as
1022        /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1023        tested.
1024    
1025    18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1026        now much more compatible with Perl, in particular in cases where the result
1027        is a non-match for a non-anchored pattern. For example, if
1028        /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1029        "m", where previously it did not return a name. A side effect of this
1030        change is that for partial matches, the last encountered mark name is
1031        returned, as for non matches. A number of tests that were previously not
1032        Perl-compatible have been moved into the Perl-compatible test files. The
1033        refactoring has had the pleasing side effect of removing one argument from
1034        the match() function, thus reducing its stack requirements.
1035    
1036    19. If the /S+ option was used in pcretest to study a pattern using JIT,
1037        subsequent uses of /S (without +) incorrectly behaved like /S+.
1038    
1039    21. Retrieve executable code size support for the JIT compiler and fixing
1040        some warnings.
1041    
1042    22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1043        not work when the shorter character appeared right at the end of the
1044        subject string.
1045    
1046    23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1047        systems.
1048    
1049    24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1050        output it when the /M option is used in pcretest.
1051    
1052    25. The CheckMan script was not being included in the distribution. Also, added
1053        an explicit "perl" to run Perl scripts from the PrepareRelease script
1054        because this is reportedly needed in Windows.
1055    
1056    26. If study data was being save in a file and studying had not found a set of
1057        "starts with" bytes for the pattern, the data written to the file (though
1058        never used) was taken from uninitialized memory and so caused valgrind to
1059        complain.
1060    
1061    27. Updated RunTest.bat as provided by Sheri Pierce.
1062    
1063    28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1064    
1065    29. Computation of memory usage for the table of capturing group names was
1066        giving an unnecessarily large value.
1067    
1068    
1069    Version 8.20 21-Oct-2011
1070    ------------------------
1071    
1072    1.  Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1073        a POSIX class. After further experiments with Perl, which convinced me that
1074        Perl has bugs and confusions, a closing square bracket is no longer allowed
1075        in a POSIX name. This bug also affected patterns with classes that started
1076        with full stops.
1077    
1078    2.  If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1079        captured substring, but while checking the failing first alternative,
1080        substring 1 is temporarily captured. If the output vector supplied to
1081        pcre_exec() was not big enough for this capture, the yield of the function
1082        was still zero ("insufficient space for captured substrings"). This cannot
1083        be totally fixed without adding another stack variable, which seems a lot
1084        of expense for a edge case. However, I have improved the situation in cases
1085        such as /(a)(b)x|abc/ matched against "abc", where the return code
1086        indicates that fewer than the maximum number of slots in the ovector have
1087        been set.
1088    
1089    3.  Related to (2) above: when there are more back references in a pattern than
1090        slots in the output vector, pcre_exec() uses temporary memory during
1091        matching, and copies in the captures as far as possible afterwards. It was
1092        using the entire output vector, but this conflicts with the specification
1093        that only 2/3 is used for passing back captured substrings. Now it uses
1094        only the first 2/3, for compatibility. This is, of course, another edge
1095        case.
1096    
1097    4.  Zoltan Herczeg's just-in-time compiler support has been integrated into the
1098        main code base, and can be used by building with --enable-jit. When this is
1099        done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1100        runtime --no-jit option is given.
1101    
1102    5.  When the number of matches in a pcre_dfa_exec() run exactly filled the
1103        ovector, the return from the function was zero, implying that there were
1104        other matches that did not fit. The correct "exactly full" value is now
1105        returned.
1106    
1107    6.  If a subpattern that was called recursively or as a subroutine contained
1108        (*PRUNE) or any other control that caused it to give a non-standard return,
1109        invalid errors such as "Error -26 (nested recursion at the same subject
1110        position)" or even infinite loops could occur.
1111    
1112    7.  If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1113        computing the minimum length on reaching *ACCEPT, and so ended up with the
1114        wrong value of 1 rather than 0. Further investigation indicates that
1115        computing a minimum subject length in the presence of *ACCEPT is difficult
1116        (think back references, subroutine calls), and so I have changed the code
1117        so that no minimum is registered for a pattern that contains *ACCEPT.
1118    
1119    8.  If (*THEN) was present in the first (true) branch of a conditional group,
1120        it was not handled as intended. [But see 16 below.]
1121    
1122    9.  Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1123        Sheri Pierce.
1124    
1125    10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1126        the first byte in a match must be "a".
1127    
1128    11. Change 17 for 8.13 increased the recursion depth for patterns like
1129        /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1130        pattern contains any instances of (*THEN). If it does not, the old
1131        optimizations are restored. It would be nice to do this on a per-group
1132        basis, but at the moment that is not feasible.
1133    
1134    12. In some environments, the output of pcretest -C is CRLF terminated. This
1135        broke RunTest's code that checks for the link size. A single white space
1136        character after the value is now allowed for.
1137    
1138    13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1139        For "fr", it uses the Windows-specific input and output files.
1140    
1141    14. If (*THEN) appeared in a group that was called recursively or as a
1142        subroutine, it did not work as intended. [But see next item.]
1143    
1144    15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1145        pattern fragments (but not containing any | characters). If A and B are
1146        matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1147        was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1148        D. In other words, Perl considers parentheses that do not contain any |
1149        characters to be part of a surrounding alternative, whereas PCRE was
1150        treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1151        differently. PCRE now behaves in the same way as Perl, except in the case
1152        of subroutine/recursion calls such as (?1) which have in any case always
1153        been different (but PCRE had them first :-).
1154    
1155    16. Related to 15 above: Perl does not treat the | in a conditional group as
1156        creating alternatives. Such a group is treated in the same way as an
1157        ordinary group without any | characters when processing (*THEN). PCRE has
1158        been changed to match Perl's behaviour.
1159    
1160    17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1161        RunGrepTest script failed.
1162    
1163    18. Change 22 for version 13 caused atomic groups to use more stack. This is
1164        inevitable for groups that contain captures, but it can lead to a lot of
1165        stack use in large patterns. The old behaviour has been restored for atomic
1166        groups that do not contain any capturing parentheses.
1167    
1168    19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1169        suppress the check for a minimum subject length at run time. (If it was
1170        given to pcre_exec() or pcre_dfa_exec() it did work.)
1171    
1172    20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1173        fail to work when decoding hex characters in data strings in EBCDIC
1174        environments.
1175    
1176    21. It appears that in at least one Mac OS environment, the isxdigit() function
1177        is implemented as a macro that evaluates to its argument more than once,
1178        contravening the C 90 Standard (I haven't checked a later standard). There
1179        was an instance in pcretest which caused it to go wrong when processing
1180        \x{...} escapes in subject strings. The has been rewritten to avoid using
1181        things like p++ in the argument of isxdigit().
1182    
1183    
1184    Version 8.13 16-Aug-2011
1185  ------------------------  ------------------------
1186    
1187  1.  The Unicode data tables have been updated to Unicode 6.0.0.  1.  The Unicode data tables have been updated to Unicode 6.0.0.
# Line 20  Version 8.13 30-Apr-2011 Line 1200  Version 8.13 30-Apr-2011
1200      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a      code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1201      2-byte code at the end of the subject (it thought there wasn't enough data      2-byte code at the end of the subject (it thought there wasn't enough data
1202      left).      left).
1203    
1204  5.  Comprehensive information about what went wrong is now returned by  5.  Comprehensive information about what went wrong is now returned by
1205      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long      pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1206      as the output vector has at least 2 elements. The offset of the start of      as the output vector has at least 2 elements. The offset of the start of
1207      the failing character and a reason code are placed in the vector.      the failing character and a reason code are placed in the vector.
1208    
1209  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is  6.  When the UTF-8 string check fails for pcre_compile(), the offset that is
1210      now returned is for the first byte of the failing character, instead of the      now returned is for the first byte of the failing character, instead of the
1211      last byte inspected. This is an incompatible change, but I hope it is small      last byte inspected. This is an incompatible change, but I hope it is small
1212      enough not to be a problem. It makes the returned offset consistent with      enough not to be a problem. It makes the returned offset consistent with
1213      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
1214    
1215  7.  pcretest now gives a text phrase as well as the error number when  7.  pcretest now gives a text phrase as well as the error number when
1216      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check      pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1217      failure, the offset and reason code are output.      failure, the offset and reason code are output.
1218    
1219  8.  When \R was used with a maximizing quantifier it failed to skip backwards  8.  When \R was used with a maximizing quantifier it failed to skip backwards
1220      over a \r\n pair if the subsequent match failed. Instead, it just skipped      over a \r\n pair if the subsequent match failed. Instead, it just skipped
1221      back over a single character (\n). This seems wrong (because it treated the      back over a single character (\n). This seems wrong (because it treated the
1222      two characters as a single entity when going forwards), conflicts with the      two characters as a single entity when going forwards), conflicts with the
1223      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the      documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1224      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour      behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1225      has been changed.      has been changed.
1226    
1227  9.  Some internal refactoring has changed the processing so that the handling  9.  Some internal refactoring has changed the processing so that the handling
1228      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile      of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1229      time (the PCRE_DOTALL option was changed this way some time ago: version      time (the PCRE_DOTALL option was changed this way some time ago: version
1230      7.7 change 16). This has made it possible to abolish the OP_OPT op code,      7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1231      which was always a bit of a fudge. It also means that there is one less      which was always a bit of a fudge. It also means that there is one less
1232      argument for the match() function, which reduces its stack requirements      argument for the match() function, which reduces its stack requirements
1233      slightly. This change also fixes an incompatibility with Perl: the pattern      slightly. This change also fixes an incompatibility with Perl: the pattern
1234      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.      (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1235    
1236  10. More internal refactoring has drastically reduced the number of recursive  10. More internal refactoring has drastically reduced the number of recursive
1237      calls to match() for possessively repeated groups such as (abc)++ when      calls to match() for possessively repeated groups such as (abc)++ when
1238      using pcre_exec().      using pcre_exec().
1239    
1240  11. While implementing 10, a number of bugs in the handling of groups were  11. While implementing 10, a number of bugs in the handling of groups were
1241      discovered and fixed:      discovered and fixed:
1242    
1243      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).      (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1244      (a|)*(?1) gave a compile-time internal error.      (a|)*(?1) gave a compile-time internal error.
1245      ((a|)+)+  did not notice that the outer group could match an empty string.      ((a|)+)+  did not notice that the outer group could match an empty string.
1246      (^a|^)+   was not marked as anchored.      (^a|^)+   was not marked as anchored.
1247      (.*a|.*)+ was not marked as matching at start or after a newline.      (.*a|.*)+ was not marked as matching at start or after a newline.
1248    
1249  12. Yet more internal refactoring has removed another argument from the match()  12. Yet more internal refactoring has removed another argument from the match()
1250      function. Special calls to this function are now indicated by setting a      function. Special calls to this function are now indicated by setting a
1251      value in a variable in the "match data" data block.      value in a variable in the "match data" data block.
1252    
1253  13. Be more explicit in pcre_study() instead of relying on "default" for  13. Be more explicit in pcre_study() instead of relying on "default" for
1254      opcodes that mean there is no starting character; this means that when new      opcodes that mean there is no starting character; this means that when new
1255      ones are added and accidentally left out of pcre_study(), testing should      ones are added and accidentally left out of pcre_study(), testing should
1256      pick them up.      pick them up.
1257    
1258  14. The -s option of pcretest has been documented for ages as being an old  14. The -s option of pcretest has been documented for ages as being an old
1259      synonym of -m (show memory usage). I have changed it to mean "force study      synonym of -m (show memory usage). I have changed it to mean "force study
1260      for every regex", that is, assume /S for every regex. This is similar to -i      for every regex", that is, assume /S for every regex. This is similar to -i
1261      and -d etc. It's slightly incompatible, but I'm hoping nobody is still      and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1262      using it. It makes it easier to run collection of tests with study enabled,      using it. It makes it easier to run collections of tests with and without
1263      and thereby test pcre_study() more easily.      study enabled, and thereby test pcre_study() more easily. All the standard
1264        tests are now run with and without -s (but some patterns can be marked as
1265        "never study" - see 20 below).
1266    
1267  15. When (*ACCEPT) was used in a subpattern that was called recursively, the  15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1268      restoration of the capturing data to the outer values was not happening      restoration of the capturing data to the outer values was not happening
1269      correctly.      correctly.
1270    
1271  16. If a recursively called subpattern ended with (*ACCEPT) and matched an  16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1272      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole      empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1273      pattern had matched an empty string, and so incorrectly returned a no      pattern had matched an empty string, and so incorrectly returned a no
1274      match.      match.
1275    
1276    17. There was optimizing code for the last branch of non-capturing parentheses,
1277        and also for the obeyed branch of a conditional subexpression, which used
1278        tail recursion to cut down on stack usage. Unfortunately, now that there is
1279        the possibility of (*THEN) occurring in these branches, tail recursion is
1280        no longer possible because the return has to be checked for (*THEN). These
1281        two optimizations have therefore been removed. [But see 8.20/11 above.]
1282    
1283    18. If a pattern containing \R was studied, it was assumed that \R always
1284        matched two bytes, thus causing the minimum subject length to be
1285        incorrectly computed because \R can also match just one byte.
1286    
1287    19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1288        was incorrectly computed.
1289    
1290    20. If /S is present twice on a test pattern in pcretest input, it now
1291        *disables* studying, thereby overriding the use of -s on the command line
1292        (see 14 above). This is necessary for one or two tests to keep the output
1293        identical in both cases.
1294    
1295    21. When (*ACCEPT) was used in an assertion that matched an empty string and
1296        PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1297    
1298    22. When an atomic group that contained a capturing parenthesis was
1299        successfully matched, but the branch in which it appeared failed, the
1300        capturing was not being forgotten if a higher numbered group was later
1301        captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1302        group 1 to "a", when in fact it should be unset. This applied to multi-
1303        branched capturing and non-capturing groups, repeated or not, and also to
1304        positive assertions (capturing in negative assertions does not happen
1305        in PCRE) and also to nested atomic groups.
1306    
1307    23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1308        subject after a captured substring, to make it easier to tell which of a
1309        number of identical substrings has been captured.
1310    
1311    24. The way atomic groups are processed by pcre_exec() has been changed so that
1312        if they are repeated, backtracking one repetition now resets captured
1313        values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1314        "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1315        "aaa". Previously, it would have been "a". As part of this code
1316        refactoring, the way recursive calls are handled has also been changed.
1317    
1318    25. If an assertion condition captured any substrings, they were not passed
1319        back unless some other capturing happened later. For example, if
1320        (?(?=(a))a) was matched against "a", no capturing was returned.
1321    
1322    26. When studying a pattern that contained subroutine calls or assertions,
1323        the code for finding the minimum length of a possible match was handling
1324        direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1325        group 1 called group 2 while simultaneously a separate group 2 called group
1326        1). A stack overflow occurred in this case. I have fixed this by limiting
1327        the recursion depth to 10.
1328    
1329    27. Updated RunTest.bat in the distribution to the version supplied by Tom
1330        Fortmann. This supports explicit test numbers on the command line, and has
1331        argument validation and error reporting.
1332    
1333    28. An instance of \X with an unlimited repeat could fail if at any point the
1334        first character it looked at was a mark character.
1335    
1336    29. Some minor code refactoring concerning Unicode properties and scripts
1337        should reduce the stack requirement of match() slightly.
1338    
1339    30. Added the '=' option to pcretest to check the setting of unused capturing
1340        slots at the end of the pattern, which are documented as being -1, but are
1341        not included in the return count.
1342    
1343    31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1344        compiled something random. Now it gives a compile-time error (as does
1345        Perl).
1346    
1347    32. A *MARK encountered during the processing of a positive assertion is now
1348        recorded and passed back (compatible with Perl).
1349    
1350    33. If --only-matching or --colour was set on a pcregrep call whose pattern
1351        had alternative anchored branches, the search for a second match in a line
1352        was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1353        matched the line "0102" twice. The same bug affected patterns that started
1354        with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1355        twice.
1356    
1357    34. Previously, PCRE did not allow quantification of assertions. However, Perl
1358        does, and because of capturing effects, quantifying parenthesized
1359        assertions may at times be useful. Quantifiers are now allowed for
1360        parenthesized assertions.
1361    
1362    35. A minor code tidy in pcre_compile() when checking options for \R usage.
1363    
1364    36. \g was being checked for fancy things in a character class, when it should
1365        just be a literal "g".
1366    
1367    37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1368        appearance of a nested POSIX class supersedes an apparent external class.
1369        For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1370        unescaped square brackets may also appear as part of class names. For
1371        example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1372        more like Perl. (But see 8.20/1 above.)
1373    
1374    38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1375        was because it thought it was \N{name}, which is not supported).
1376    
1377    39. Add minix to OS list not supporting the -S option in pcretest.
1378    
1379    40. PCRE tries to detect cases of infinite recursion at compile time, but it
1380        cannot analyze patterns in sufficient detail to catch mutual recursions
1381        such as ((?1))((?2)). There is now a runtime test that gives an error if a
1382        subgroup is called recursively as a subpattern for a second time at the
1383        same position in the subject string. In previous releases this might have
1384        been caught by the recursion limit, or it might have run out of stack.
1385    
1386    41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1387        happen only once. PCRE was, however incorrectly giving a compile time error
1388        "recursive call could loop indefinitely" because it cannot analyze the
1389        pattern in sufficient detail. The compile time test no longer happens when
1390        PCRE is compiling a conditional subpattern, but actual runaway loops are
1391        now caught at runtime (see 40 above).
1392    
1393    42. It seems that Perl allows any characters other than a closing parenthesis
1394        to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1395        has been changed to be the same.
1396    
1397    43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1398        as not to get warnings when autogen.sh is called. Also changed
1399        AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1400    
1401    44. To help people who use pcregrep to scan files containing exceedingly long
1402        lines, the following changes have been made:
1403    
1404        (a) The default value of the buffer size parameter has been increased from
1405            8K to 20K. (The actual buffer used is three times this size.)
1406    
1407        (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1408            PCRE is built.
1409    
1410        (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1411            to be set at run time.
1412    
1413        (d) Numerical values in pcregrep options can be followed by K or M, for
1414            example --buffer-size=50K.
1415    
1416        (e) If a line being scanned overflows pcregrep's buffer, an error is now
1417            given and the return code is set to 2.
1418    
1419    45. Add a pointer to the latest mark to the callout data block.
1420    
1421    46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1422        partial match of an empty string instead of no match. This was specific to
1423        the use of ".".
1424    
1425    47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1426        complete match instead of a partial match. This bug was dependent on both
1427        the PCRE_UTF8 and PCRE_DOTALL options being set.
1428    
1429    48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1430        starting byte set, because \b was not being ignored.
1431    
1432    
1433  Version 8.12 15-Jan-2011  Version 8.12 15-Jan-2011
1434  ------------------------  ------------------------
# Line 742  Version 7.9 11-Apr-09 Line 2080  Version 7.9 11-Apr-09
2080  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
2081      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
2082      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this      locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2083      seems to be how GNU grep behaves.      seems to be how GNU grep behaves. [But see later change 40 for release
2084        8.33.]
2085    
2086  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
2087      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 985  Version 7.7 07-May-08 Line 2324  Version 7.7 07-May-08
2324      containing () gave an internal compiling error instead of "reference to      containing () gave an internal compiling error instead of "reference to
2325      non-existent subpattern". Fortunately, when the pattern did exist, the      non-existent subpattern". Fortunately, when the pattern did exist, the
2326      compiled code was correct. (When scanning forwards to check for the      compiled code was correct. (When scanning forwards to check for the
2327      existencd of the subpattern, it was treating the data ']' as terminating      existence of the subpattern, it was treating the data ']' as terminating
2328      the class, so got the count wrong. When actually compiling, the reference      the class, so got the count wrong. When actually compiling, the reference
2329      was subsequently set up correctly.)      was subsequently set up correctly.)
2330    

Legend:
Removed from v.608  
changed lines
  Added in v.1488

  ViewVC Help
Powered by ViewVC 1.1.5