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revision 474 by ph10, Sat Jan 2 16:30:46 2010 UTC revision 517 by ph10, Wed May 5 10:44:20 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.01 11-Dec-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  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()      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      computed the wrong minimum data length (which is of course zero for such
107      subpatterns).      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  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      the pattern is reset in the first branch, pcre_compile() failed with
# Line 26  Version 8.01 11-Dec-09 Line 123  Version 8.01 11-Dec-09
123      assertion subpattern, including such a pattern used as a condition,      assertion subpattern, including such a pattern used as a condition,
124      unpredictable results occurred, instead of the error return      unpredictable results occurred, instead of the error return
125      PCRE_ERROR_DFA_UITEM.      PCRE_ERROR_DFA_UITEM.
126    
127  5.  The C++ GlobalReplace function was not working like Perl for the special  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      situation when an empty string is matched. It now does the fancy magic
129      stuff that is necessary.      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  Version 8.00 19-Oct-09

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