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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.9 xx-xxx-09  Version 8.10 03 May-2010
5    ------------------------
7    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8        THEN.
10    2.  (*ACCEPT) was not working when inside an atomic group.
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.
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.
21    Version 8.02 19-Mar-2010
22    ------------------------
24    1.  The Unicode data tables have been updated to Unicode 5.2.0.
26    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
27        configured.
29    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
30        original author of that file, following a query about its status.
32    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
33        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
35    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
36        quantifier applied to a forward-referencing subroutine call, could compile
37        incorrect code or give the error "internal error: previously-checked
38        referenced subpattern not found".
40    6.  Both MS Visual Studio and Symbian OS have problems with initializing
41        variables to point to external functions. For these systems, therefore,
42        pcre_malloc etc. are now initialized to local functions that call the
43        relevant global functions.
45    7.  There were two entries missing in the vectors called coptable and poptable
46        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
47        I've fixed the data, and added a kludgy way of testing at compile time that
48        the lengths are correct (equal to the number of opcodes).
50    8.  Following on from 7, I added a similar kludge to check the length of the
51        eint vector in pcreposix.c.
53    9.  Error texts for pcre_compile() are held as one long string to avoid too
54        much relocation at load time. To find a text, the string is searched,
55        counting zeros. There was no check for running off the end of the string,
56        which could happen if a new error number was added without updating the
57        string.
59    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
61    11. \K was not working if it appeared in an atomic group or in a group that
62        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
63        \K is "not well defined" if used in an assertion. PCRE now accepts it if
64        the assertion is positive, but not if it is negative.
66    12. Change 11 fortuitously reduced the size of the stack frame used in the
67        "match()" function of pcre_exec.c by one pointer. Forthcoming
68        implementation of support for (*MARK) will need an extra pointer on the
69        stack; I have reserved it now, so that the stack frame size does not
70        decrease.
72    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
73        item in branch that calls a recursion is a subroutine call - as in the
74        second branch in the above example - was incorrectly given the compile-
75        time error "recursive call could loop indefinitely" because pcre_compile()
76        was not correctly checking the subroutine for matching a non-empty string.
78    14. The checks for overrunning compiling workspace could trigger after an
79        overrun had occurred. This is a "should never occur" error, but it can be
80        triggered by pathological patterns such as hundreds of nested parentheses.
81        The checks now trigger 100 bytes before the end of the workspace.
83    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
86    Version 8.01 19-Jan-2010
87    ------------------------
89    1.  If a pattern contained a conditional subpattern with only one branch (in
90        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
91        computed the wrong minimum data length (which is of course zero for such
92        subpatterns). This could cause incorrect "no match" results.
94    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
95        the pattern is reset in the first branch, pcre_compile() failed with
96        "internal error: code overflow at offset...". This happened only when
97        the reset was to the original external option setting. (An optimization
98        abstracts leading options settings into an external setting, which was the
99        cause of this.)
101    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
102        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
103        assertion pattern did not match (meaning that the assertion was true), it
104        was incorrectly treated as false if the SKIP had been reached during the
105        matching. This also applied to assertions used as conditions.
107    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
108        assertion subpattern, including such a pattern used as a condition,
109        unpredictable results occurred, instead of the error return
112    5.  The C++ GlobalReplace function was not working like Perl for the special
113        situation when an empty string is matched. It now does the fancy magic
114        stuff that is necessary.
116    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
117        removed. (These were left over from very, very early versions of PCRE.)
119    7.  Some cosmetic changes to the code to make life easier when compiling it
120        as part of something else:
122        (a) Change DEBUG to PCRE_DEBUG.
124        (b) In pcre_compile(), rename the member of the "branch_chain" structure
125            called "current" as "current_branch", to prevent a collision with the
126            Linux macro when compiled as a kernel module.
128        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
129            prevent a collision with the Linux macro when compiled as a kernel
130            module.
132    8.  In pcre_compile() there are some checks for integer overflows that used to
133        cast potentially large values to (double). This has been changed to that
134        when building, a check for int64_t is made, and if it is found, it is used
135        instead, thus avoiding the use of floating point arithmetic. (There is no
136        other use of FP in PCRE.) If int64_t is not found, the fallback is to
137        double.
139    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
140        2005 (difference between two addresses compared to an unsigned value).
142    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
143        custom one, because of the following reported problem in Windows:
145          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
146              under Win32.
147          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
148              therefore missing the function definition.
149          - The compiler thus generates a "C" signature for the test function.
150          - The linker fails to find the "C" function.
151          - PCRE fails to configure if asked to do so against libbz2.
153    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
154        messages were output:
156          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
157          rerunning libtoolize, to keep the correct libtool macros in-tree.
158          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
160        I have done both of these things.
162    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
163        most of the time, it *can* run out if it is given a pattern that contains a
164        runaway infinite recursion. I updated the discussion in the pcrestack man
165        page.
167    13. Now that we have gone to the x.xx style of version numbers, the minor
168        version may start with zero. Using 08 or 09 is a bad idea because users
169        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
170        interpreted as invalid octal numbers. I've updated the previous comment in
171        configure.ac, and also added a check that gives an error if 08 or 09 are
172        used.
174    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
175        causing partial matching to fail when the end of the subject matched \W
176        in a UTF-8 pattern where \W was quantified with a minimum of 3.
178    15. There were some discrepancies between the declarations in pcre_internal.h
179        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
180        their definitions. The declarations used "const uschar *" and the
181        definitions used USPTR. Even though USPTR is normally defined as "const
182        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
183        reported that: "This difference in casting confuses some C++ compilers, for
184        example, SunCC recognizes above declarations as different functions and
185        generates broken code for hbpcre." I have changed the declarations to use
186        USPTR.
188    16. GNU libtool is named differently on some systems. The autogen.sh script now
189        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
190        (FreeBSD).
192    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
193        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
194        comment: "Figure out how to create a longlong from a string: strtoll and
195        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
196        instance, but it only takes 2 args instead of 3!"
198    18. A subtle bug concerned with back references has been fixed by a change of
199        specification, with a corresponding code fix. A pattern such as
200        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
201        refers, was giving matches when it shouldn't. For example, xa=xaaa would
202        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
203        same bug. Such groups have to be quantified to be useful, or contained
204        inside another quantified group. (If there's no repetition, the reference
205        can never match.) The problem arises because, having left the group and
206        moved on to the rest of the pattern, a later failure that backtracks into
207        the group uses the captured value from the final iteration of the group
208        rather than the correct earlier one. I have fixed this in PCRE by forcing
209        any group that contains a reference to itself to be an atomic group; that
210        is, there cannot be any backtracking into it once it has completed. This is
211        similar to recursive and subroutine calls.
214    Version 8.00 19-Oct-09
215    ----------------------
217    1.  The table for translating pcre_compile() error codes into POSIX error codes
218        was out-of-date, and there was no check on the pcre_compile() error code
219        being within the table. This could lead to an OK return being given in
220        error.
222    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
223        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
224        in a Windows environment.
226    3.  The pcregrep --count option prints the count for each file even when it is
227        zero, as does GNU grep. However, pcregrep was also printing all files when
228        --files-with-matches was added. Now, when both options are given, it prints
229        counts only for those files that have at least one match. (GNU grep just
230        prints the file name in this circumstance, but including the count seems
231        more useful - otherwise, why use --count?) Also ensured that the
232        combination -clh just lists non-zero counts, with no names.
234    4.  The long form of the pcregrep -F option was incorrectly implemented as
235        --fixed_strings instead of --fixed-strings. This is an incompatible change,
236        but it seems right to fix it, and I didn't think it was worth preserving
237        the old behaviour.
239    5.  The command line items --regex=pattern and --regexp=pattern were not
240        recognized by pcregrep, which required --regex pattern or --regexp pattern
241        (with a space rather than an '='). The man page documented the '=' forms,
242        which are compatible with GNU grep; these now work.
244    6.  No libpcreposix.pc file was created for pkg-config; there was just
245        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
247    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
248        when UCP support is not needed, by modifying the Python script that
249        generates it from Unicode data files. This should not matter if the module
250        is correctly used as a library, but I received one complaint about 50K of
251        unwanted data. My guess is that the person linked everything into his
252        program rather than using a library. Anyway, it does no harm.
254    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
255        was a minimum greater than 1 for a wide character in a possessive
256        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
257        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
258        character. Chaos in the form of incorrect output or a compiling loop could
259        result.
261    9.  The restrictions on what a pattern can contain when partial matching is
262        requested for pcre_exec() have been removed. All patterns can now be
263        partially matched by this function. In addition, if there are at least two
264        slots in the offset vector, the offset of the earliest inspected character
265        for the match and the offset of the end of the subject are set in them when
266        PCRE_ERROR_PARTIAL is returned.
268    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
269        synonymous with PCRE_PARTIAL, for backwards compatibility, and
270        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
271        and may be more useful for multi-segment matching.
273    11. Partial matching with pcre_exec() is now more intuitive. A partial match
274        used to be given if ever the end of the subject was reached; now it is
275        given only if matching could not proceed because another character was
276        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
277        string "Z", which now yields "no match" instead of "partial match". In the
278        case of pcre_dfa_exec(), "no match" is given if every matching path for the
279        final character ended with (*FAIL).
281    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
282        if the pattern had a "must contain" character that was already found in the
283        earlier partial match, unless partial matching was again requested. For
284        example, with the pattern /dog.(body)?/, the "must contain" character is
285        "g". If the first part-match was for the string "dog", restarting with
286        "sbody" failed. This bug has been fixed.
288    13. The string returned by pcre_dfa_exec() after a partial match has been
289        changed so that it starts at the first inspected character rather than the
290        first character of the match. This makes a difference only if the pattern
291        starts with a lookbehind assertion or \b or \B (\K is not supported by
292        pcre_dfa_exec()). It's an incompatible change, but it makes the two
293        matching functions compatible, and I think it's the right thing to do.
295    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
296        so that the demonstration program is easily available in environments where
297        PCRE has not been installed from source.
299    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
300        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
301        library.
303    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
304        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
305        is not the first non-POSIX option to be added. Clearly some people find
306        these options useful.
308    17. If a caller to the POSIX matching function regexec() passes a non-zero
309        value for nmatch with a NULL value for pmatch, the value of
310        nmatch is forced to zero.
312    18. RunGrepTest did not have a test for the availability of the -u option of
313        the diff command, as RunTest does. It now checks in the same way as
314        RunTest, and also checks for the -b option.
316    19. If an odd number of negated classes containing just a single character
317        interposed, within parentheses, between a forward reference to a named
318        subpattern and the definition of the subpattern, compilation crashed with
319        an internal error, complaining that it could not find the referenced
320        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
321        [The bug was that it was starting one character too far in when skipping
322        over the character class, thus treating the ] as data rather than
323        terminating the class. This meant it could skip too much.]
325    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
326        /g option in pcretest when the pattern contains \K, which makes it possible
327        to have an empty string match not at the start, even when the pattern is
328        anchored. Updated pcretest and pcredemo to use this option.
330    21. If the maximum number of capturing subpatterns in a recursion was greater
331        than the maximum at the outer level, the higher number was returned, but
332        with unset values at the outer level. The correct (outer level) value is
333        now given.
335    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
336        PCRE did not set those parentheses (unlike Perl). I have now found a way to
337        make it do so. The string so far is captured, making this feature
338        compatible with Perl.
340    23. The tests have been re-organized, adding tests 11 and 12, to make it
341        possible to check the Perl 5.10 features against Perl 5.10.
343    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
344        pattern matches a fixed length string. PCRE did not allow this; now it
345        does. Neither allows recursion.
347    25. I finally figured out how to implement a request to provide the minimum
348        length of subject string that was needed in order to match a given pattern.
349        (It was back references and recursion that I had previously got hung up
350        on.) This code has now been added to pcre_study(); it finds a lower bound
351        to the length of subject needed. It is not necessarily the greatest lower
352        bound, but using it to avoid searching strings that are too short does give
353        some useful speed-ups. The value is available to calling programs via
354        pcre_fullinfo().
356    26. While implementing 25, I discovered to my embarrassment that pcretest had
357        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
358        study optimizations had never been tested with that matching function.
359        Oops. What is worse, even when it was passed study data, there was a bug in
360        pcre_dfa_exec() that meant it never actually used it. Double oops. There
361        were also very few tests of studied patterns with pcre_dfa_exec().
363    27. If (?| is used to create subpatterns with duplicate numbers, they are now
364        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
365        on the other side of the coin, they are no longer allowed to have different
366        names, because these cannot be distinguished in PCRE, and this has caused
367        confusion. (This is a difference from Perl.)
369    28. When duplicate subpattern names are present (necessarily with different
370        numbers, as required by 27 above), and a test is made by name in a
371        conditional pattern, either for a subpattern having been matched, or for
372        recursion in such a pattern, all the associated numbered subpatterns are
373        tested, and the overall condition is true if the condition is true for any
374        one of them. This is the way Perl works, and is also more like the way
375        testing by number works.
378    Version 7.9 11-Apr-09
379  ---------------------  ---------------------
381  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 391  Version 7.9 xx-xxx-09
391      but BOOL is not.      but BOOL is not.
393  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
394      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.
396  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
397      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 468  Version 7.9 xx-xxx-09
468  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
469      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
470      included within another project.      included within another project.
472  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,
473      slightly modified by me:      slightly modified by me:
475        (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
476            not building pcregrep.            not building pcregrep.
478        (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
479            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.
481    25. Forward references, both numeric and by name, in patterns that made use of
482        duplicate group numbers, could behave incorrectly or give incorrect errors,
483        because when scanning forward to find the reference group, PCRE was not
484        taking into account the duplicate group numbers. A pattern such as
485        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
487    26. Changed a few more instances of "const unsigned char *" to USPTR, making
488        the feature of a custom pointer more persuasive (as requested by a user).
490    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
491        pcretest.c, inside #ifndefs, because it seems they are sometimes already
492        pre-defined.
494    28. Added support for (*UTF8) at the start of a pattern.
496    29. Arrange for flags added by the "release type" setting in CMake to be shown
497        in the configuration summary.
500  Version 7.8 05-Sep-08  Version 7.8 05-Sep-08

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