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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.9 xx-xxx-09  Version 8.10 03 May-2010
5    ------------------------
6    
7    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8        THEN.
9    
10    2.  (*ACCEPT) was not working when inside an atomic group.
11    
12    3.  Inside a character class, \B is treated as a literal by default, but
13        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14        causes the error). The code is unchanged, but I tidied the documentation.
15    
16    4.  Inside a character class, PCRE always treated \R and \X as literals,
17        whereas Perl faults them if its -w option is set. I have changed PCRE so
18        that it faults them when PCRE_EXTRA is set.
19    
20    5.  Added support for \N, which always matches any character other than
21        newline. (It is the same as "." when PCRE_DOTALL is not set.)
22    
23    6.  When compiling pcregrep with newer versions of gcc which may have
24        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25        declared with attribute warn_unused_result" were given. Just casting the
26        result to (void) does not stop the warnings; a more elaborate fudge is
27        needed. I've used a macro to implement this.
28    
29    7.  Minor change to pcretest.c to avoid a compiler warning.
30    
31    8.  Added four artifical Unicode properties to help with an option to make
32        \s etc use properties. The new properties are: Xan (alphanumeric), Xsp
33        (Perl space), Xps (POSIX space), and Xwd (word).
34    
35    
36    Version 8.02 19-Mar-2010
37    ------------------------
38    
39    1.  The Unicode data tables have been updated to Unicode 5.2.0.
40    
41    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
42        configured.
43    
44    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
45        original author of that file, following a query about its status.
46    
47    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
48        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
49    
50    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
51        quantifier applied to a forward-referencing subroutine call, could compile
52        incorrect code or give the error "internal error: previously-checked
53        referenced subpattern not found".
54    
55    6.  Both MS Visual Studio and Symbian OS have problems with initializing
56        variables to point to external functions. For these systems, therefore,
57        pcre_malloc etc. are now initialized to local functions that call the
58        relevant global functions.
59    
60    7.  There were two entries missing in the vectors called coptable and poptable
61        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
62        I've fixed the data, and added a kludgy way of testing at compile time that
63        the lengths are correct (equal to the number of opcodes).
64    
65    8.  Following on from 7, I added a similar kludge to check the length of the
66        eint vector in pcreposix.c.
67    
68    9.  Error texts for pcre_compile() are held as one long string to avoid too
69        much relocation at load time. To find a text, the string is searched,
70        counting zeros. There was no check for running off the end of the string,
71        which could happen if a new error number was added without updating the
72        string.
73    
74    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
75    
76    11. \K was not working if it appeared in an atomic group or in a group that
77        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
78        \K is "not well defined" if used in an assertion. PCRE now accepts it if
79        the assertion is positive, but not if it is negative.
80    
81    12. Change 11 fortuitously reduced the size of the stack frame used in the
82        "match()" function of pcre_exec.c by one pointer. Forthcoming
83        implementation of support for (*MARK) will need an extra pointer on the
84        stack; I have reserved it now, so that the stack frame size does not
85        decrease.
86    
87    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
88        item in branch that calls a recursion is a subroutine call - as in the
89        second branch in the above example - was incorrectly given the compile-
90        time error "recursive call could loop indefinitely" because pcre_compile()
91        was not correctly checking the subroutine for matching a non-empty string.
92    
93    14. The checks for overrunning compiling workspace could trigger after an
94        overrun had occurred. This is a "should never occur" error, but it can be
95        triggered by pathological patterns such as hundreds of nested parentheses.
96        The checks now trigger 100 bytes before the end of the workspace.
97    
98    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
99    
100    
101    Version 8.01 19-Jan-2010
102    ------------------------
103    
104    1.  If a pattern contained a conditional subpattern with only one branch (in
105        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
106        computed the wrong minimum data length (which is of course zero for such
107        subpatterns). This could cause incorrect "no match" results.
108    
109    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
110        the pattern is reset in the first branch, pcre_compile() failed with
111        "internal error: code overflow at offset...". This happened only when
112        the reset was to the original external option setting. (An optimization
113        abstracts leading options settings into an external setting, which was the
114        cause of this.)
115    
116    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
117        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
118        assertion pattern did not match (meaning that the assertion was true), it
119        was incorrectly treated as false if the SKIP had been reached during the
120        matching. This also applied to assertions used as conditions.
121    
122    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
123        assertion subpattern, including such a pattern used as a condition,
124        unpredictable results occurred, instead of the error return
125        PCRE_ERROR_DFA_UITEM.
126    
127    5.  The C++ GlobalReplace function was not working like Perl for the special
128        situation when an empty string is matched. It now does the fancy magic
129        stuff that is necessary.
130    
131    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
132        removed. (These were left over from very, very early versions of PCRE.)
133    
134    7.  Some cosmetic changes to the code to make life easier when compiling it
135        as part of something else:
136    
137        (a) Change DEBUG to PCRE_DEBUG.
138    
139        (b) In pcre_compile(), rename the member of the "branch_chain" structure
140            called "current" as "current_branch", to prevent a collision with the
141            Linux macro when compiled as a kernel module.
142    
143        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
144            prevent a collision with the Linux macro when compiled as a kernel
145            module.
146    
147    8.  In pcre_compile() there are some checks for integer overflows that used to
148        cast potentially large values to (double). This has been changed to that
149        when building, a check for int64_t is made, and if it is found, it is used
150        instead, thus avoiding the use of floating point arithmetic. (There is no
151        other use of FP in PCRE.) If int64_t is not found, the fallback is to
152        double.
153    
154    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
155        2005 (difference between two addresses compared to an unsigned value).
156    
157    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
158        custom one, because of the following reported problem in Windows:
159    
160          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
161              under Win32.
162          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
163              therefore missing the function definition.
164          - The compiler thus generates a "C" signature for the test function.
165          - The linker fails to find the "C" function.
166          - PCRE fails to configure if asked to do so against libbz2.
167    
168    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
169        messages were output:
170    
171          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
172          rerunning libtoolize, to keep the correct libtool macros in-tree.
173          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
174    
175        I have done both of these things.
176    
177    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
178        most of the time, it *can* run out if it is given a pattern that contains a
179        runaway infinite recursion. I updated the discussion in the pcrestack man
180        page.
181    
182    13. Now that we have gone to the x.xx style of version numbers, the minor
183        version may start with zero. Using 08 or 09 is a bad idea because users
184        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
185        interpreted as invalid octal numbers. I've updated the previous comment in
186        configure.ac, and also added a check that gives an error if 08 or 09 are
187        used.
188    
189    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
190        causing partial matching to fail when the end of the subject matched \W
191        in a UTF-8 pattern where \W was quantified with a minimum of 3.
192    
193    15. There were some discrepancies between the declarations in pcre_internal.h
194        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
195        their definitions. The declarations used "const uschar *" and the
196        definitions used USPTR. Even though USPTR is normally defined as "const
197        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
198        reported that: "This difference in casting confuses some C++ compilers, for
199        example, SunCC recognizes above declarations as different functions and
200        generates broken code for hbpcre." I have changed the declarations to use
201        USPTR.
202    
203    16. GNU libtool is named differently on some systems. The autogen.sh script now
204        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
205        (FreeBSD).
206    
207    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
208        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
209        comment: "Figure out how to create a longlong from a string: strtoll and
210        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
211        instance, but it only takes 2 args instead of 3!"
212    
213    18. A subtle bug concerned with back references has been fixed by a change of
214        specification, with a corresponding code fix. A pattern such as
215        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
216        refers, was giving matches when it shouldn't. For example, xa=xaaa would
217        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
218        same bug. Such groups have to be quantified to be useful, or contained
219        inside another quantified group. (If there's no repetition, the reference
220        can never match.) The problem arises because, having left the group and
221        moved on to the rest of the pattern, a later failure that backtracks into
222        the group uses the captured value from the final iteration of the group
223        rather than the correct earlier one. I have fixed this in PCRE by forcing
224        any group that contains a reference to itself to be an atomic group; that
225        is, there cannot be any backtracking into it once it has completed. This is
226        similar to recursive and subroutine calls.
227    
228    
229    Version 8.00 19-Oct-09
230    ----------------------
231    
232    1.  The table for translating pcre_compile() error codes into POSIX error codes
233        was out-of-date, and there was no check on the pcre_compile() error code
234        being within the table. This could lead to an OK return being given in
235        error.
236    
237    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
238        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
239        in a Windows environment.
240    
241    3.  The pcregrep --count option prints the count for each file even when it is
242        zero, as does GNU grep. However, pcregrep was also printing all files when
243        --files-with-matches was added. Now, when both options are given, it prints
244        counts only for those files that have at least one match. (GNU grep just
245        prints the file name in this circumstance, but including the count seems
246        more useful - otherwise, why use --count?) Also ensured that the
247        combination -clh just lists non-zero counts, with no names.
248    
249    4.  The long form of the pcregrep -F option was incorrectly implemented as
250        --fixed_strings instead of --fixed-strings. This is an incompatible change,
251        but it seems right to fix it, and I didn't think it was worth preserving
252        the old behaviour.
253    
254    5.  The command line items --regex=pattern and --regexp=pattern were not
255        recognized by pcregrep, which required --regex pattern or --regexp pattern
256        (with a space rather than an '='). The man page documented the '=' forms,
257        which are compatible with GNU grep; these now work.
258    
259    6.  No libpcreposix.pc file was created for pkg-config; there was just
260        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
261    
262    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
263        when UCP support is not needed, by modifying the Python script that
264        generates it from Unicode data files. This should not matter if the module
265        is correctly used as a library, but I received one complaint about 50K of
266        unwanted data. My guess is that the person linked everything into his
267        program rather than using a library. Anyway, it does no harm.
268    
269    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
270        was a minimum greater than 1 for a wide character in a possessive
271        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
272        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
273        character. Chaos in the form of incorrect output or a compiling loop could
274        result.
275    
276    9.  The restrictions on what a pattern can contain when partial matching is
277        requested for pcre_exec() have been removed. All patterns can now be
278        partially matched by this function. In addition, if there are at least two
279        slots in the offset vector, the offset of the earliest inspected character
280        for the match and the offset of the end of the subject are set in them when
281        PCRE_ERROR_PARTIAL is returned.
282    
283    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
284        synonymous with PCRE_PARTIAL, for backwards compatibility, and
285        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
286        and may be more useful for multi-segment matching.
287    
288    11. Partial matching with pcre_exec() is now more intuitive. A partial match
289        used to be given if ever the end of the subject was reached; now it is
290        given only if matching could not proceed because another character was
291        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
292        string "Z", which now yields "no match" instead of "partial match". In the
293        case of pcre_dfa_exec(), "no match" is given if every matching path for the
294        final character ended with (*FAIL).
295    
296    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
297        if the pattern had a "must contain" character that was already found in the
298        earlier partial match, unless partial matching was again requested. For
299        example, with the pattern /dog.(body)?/, the "must contain" character is
300        "g". If the first part-match was for the string "dog", restarting with
301        "sbody" failed. This bug has been fixed.
302    
303    13. The string returned by pcre_dfa_exec() after a partial match has been
304        changed so that it starts at the first inspected character rather than the
305        first character of the match. This makes a difference only if the pattern
306        starts with a lookbehind assertion or \b or \B (\K is not supported by
307        pcre_dfa_exec()). It's an incompatible change, but it makes the two
308        matching functions compatible, and I think it's the right thing to do.
309    
310    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
311        so that the demonstration program is easily available in environments where
312        PCRE has not been installed from source.
313    
314    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
315        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
316        library.
317    
318    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
319        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
320        is not the first non-POSIX option to be added. Clearly some people find
321        these options useful.
322    
323    17. If a caller to the POSIX matching function regexec() passes a non-zero
324        value for nmatch with a NULL value for pmatch, the value of
325        nmatch is forced to zero.
326    
327    18. RunGrepTest did not have a test for the availability of the -u option of
328        the diff command, as RunTest does. It now checks in the same way as
329        RunTest, and also checks for the -b option.
330    
331    19. If an odd number of negated classes containing just a single character
332        interposed, within parentheses, between a forward reference to a named
333        subpattern and the definition of the subpattern, compilation crashed with
334        an internal error, complaining that it could not find the referenced
335        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
336        [The bug was that it was starting one character too far in when skipping
337        over the character class, thus treating the ] as data rather than
338        terminating the class. This meant it could skip too much.]
339    
340    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
341        /g option in pcretest when the pattern contains \K, which makes it possible
342        to have an empty string match not at the start, even when the pattern is
343        anchored. Updated pcretest and pcredemo to use this option.
344    
345    21. If the maximum number of capturing subpatterns in a recursion was greater
346        than the maximum at the outer level, the higher number was returned, but
347        with unset values at the outer level. The correct (outer level) value is
348        now given.
349    
350    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
351        PCRE did not set those parentheses (unlike Perl). I have now found a way to
352        make it do so. The string so far is captured, making this feature
353        compatible with Perl.
354    
355    23. The tests have been re-organized, adding tests 11 and 12, to make it
356        possible to check the Perl 5.10 features against Perl 5.10.
357    
358    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
359        pattern matches a fixed length string. PCRE did not allow this; now it
360        does. Neither allows recursion.
361    
362    25. I finally figured out how to implement a request to provide the minimum
363        length of subject string that was needed in order to match a given pattern.
364        (It was back references and recursion that I had previously got hung up
365        on.) This code has now been added to pcre_study(); it finds a lower bound
366        to the length of subject needed. It is not necessarily the greatest lower
367        bound, but using it to avoid searching strings that are too short does give
368        some useful speed-ups. The value is available to calling programs via
369        pcre_fullinfo().
370    
371    26. While implementing 25, I discovered to my embarrassment that pcretest had
372        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
373        study optimizations had never been tested with that matching function.
374        Oops. What is worse, even when it was passed study data, there was a bug in
375        pcre_dfa_exec() that meant it never actually used it. Double oops. There
376        were also very few tests of studied patterns with pcre_dfa_exec().
377    
378    27. If (?| is used to create subpatterns with duplicate numbers, they are now
379        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
380        on the other side of the coin, they are no longer allowed to have different
381        names, because these cannot be distinguished in PCRE, and this has caused
382        confusion. (This is a difference from Perl.)
383    
384    28. When duplicate subpattern names are present (necessarily with different
385        numbers, as required by 27 above), and a test is made by name in a
386        conditional pattern, either for a subpattern having been matched, or for
387        recursion in such a pattern, all the associated numbered subpatterns are
388        tested, and the overall condition is true if the condition is true for any
389        one of them. This is the way Perl works, and is also more like the way
390        testing by number works.
391    
392    
393    Version 7.9 11-Apr-09
394  ---------------------  ---------------------
395    
396  1.  When building with support for bzlib/zlib (pcregrep) and/or readline  1.  When building with support for bzlib/zlib (pcregrep) and/or readline
# Line 17  Version 7.9 xx-xxx-09 Line 406  Version 7.9 xx-xxx-09
406      but BOOL is not.      but BOOL is not.
407    
408  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
409      PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.      PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
410    
411  4.  The pcregrep documentation said spaces were inserted as well as colons (or  4.  The pcregrep documentation said spaces were inserted as well as colons (or
412      hyphens) following file names and line numbers when outputting matching      hyphens) following file names and line numbers when outputting matching
# Line 94  Version 7.9 xx-xxx-09 Line 483  Version 7.9 xx-xxx-09
483  23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name  23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
484      CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is      CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
485      included within another project.      included within another project.
486    
487  24. Steven Van Ingelgem's patches to add more options to the CMake support,  24. Steven Van Ingelgem's patches to add more options to the CMake support,
488      slightly modified by me:      slightly modified by me:
489    
490        (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including        (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
491            not building pcregrep.            not building pcregrep.
492    
493        (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only        (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
494            if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.            if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
495    
496    25. Forward references, both numeric and by name, in patterns that made use of
497        duplicate group numbers, could behave incorrectly or give incorrect errors,
498        because when scanning forward to find the reference group, PCRE was not
499        taking into account the duplicate group numbers. A pattern such as
500        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
501    
502    26. Changed a few more instances of "const unsigned char *" to USPTR, making
503        the feature of a custom pointer more persuasive (as requested by a user).
504    
505    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
506        pcretest.c, inside #ifndefs, because it seems they are sometimes already
507        pre-defined.
508    
509    28. Added support for (*UTF8) at the start of a pattern.
510    
511    29. Arrange for flags added by the "release type" setting in CMake to be shown
512        in the configuration summary.
513    
514    
515  Version 7.8 05-Sep-08  Version 7.8 05-Sep-08

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