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revision 461 by ph10, Mon Oct 5 10:59:35 2009 UTC revision 515 by ph10, Tue May 4 09:12:25 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.00 05-Oct-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    
30    Version 8.02 19-Mar-2010
31    ------------------------
32    
33    1.  The Unicode data tables have been updated to Unicode 5.2.0.
34    
35    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
36        configured.
37    
38    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
39        original author of that file, following a query about its status.
40    
41    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
42        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
43    
44    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
45        quantifier applied to a forward-referencing subroutine call, could compile
46        incorrect code or give the error "internal error: previously-checked
47        referenced subpattern not found".
48    
49    6.  Both MS Visual Studio and Symbian OS have problems with initializing
50        variables to point to external functions. For these systems, therefore,
51        pcre_malloc etc. are now initialized to local functions that call the
52        relevant global functions.
53    
54    7.  There were two entries missing in the vectors called coptable and poptable
55        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
56        I've fixed the data, and added a kludgy way of testing at compile time that
57        the lengths are correct (equal to the number of opcodes).
58    
59    8.  Following on from 7, I added a similar kludge to check the length of the
60        eint vector in pcreposix.c.
61    
62    9.  Error texts for pcre_compile() are held as one long string to avoid too
63        much relocation at load time. To find a text, the string is searched,
64        counting zeros. There was no check for running off the end of the string,
65        which could happen if a new error number was added without updating the
66        string.
67    
68    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
69    
70    11. \K was not working if it appeared in an atomic group or in a group that
71        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
72        \K is "not well defined" if used in an assertion. PCRE now accepts it if
73        the assertion is positive, but not if it is negative.
74    
75    12. Change 11 fortuitously reduced the size of the stack frame used in the
76        "match()" function of pcre_exec.c by one pointer. Forthcoming
77        implementation of support for (*MARK) will need an extra pointer on the
78        stack; I have reserved it now, so that the stack frame size does not
79        decrease.
80    
81    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
82        item in branch that calls a recursion is a subroutine call - as in the
83        second branch in the above example - was incorrectly given the compile-
84        time error "recursive call could loop indefinitely" because pcre_compile()
85        was not correctly checking the subroutine for matching a non-empty string.
86    
87    14. The checks for overrunning compiling workspace could trigger after an
88        overrun had occurred. This is a "should never occur" error, but it can be
89        triggered by pathological patterns such as hundreds of nested parentheses.
90        The checks now trigger 100 bytes before the end of the workspace.
91    
92    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
93    
94    
95    Version 8.01 19-Jan-2010
96    ------------------------
97    
98    1.  If a pattern contained a conditional subpattern with only one branch (in
99        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
100        computed the wrong minimum data length (which is of course zero for such
101        subpatterns). This could cause incorrect "no match" results.
102    
103    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
104        the pattern is reset in the first branch, pcre_compile() failed with
105        "internal error: code overflow at offset...". This happened only when
106        the reset was to the original external option setting. (An optimization
107        abstracts leading options settings into an external setting, which was the
108        cause of this.)
109    
110    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
111        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
112        assertion pattern did not match (meaning that the assertion was true), it
113        was incorrectly treated as false if the SKIP had been reached during the
114        matching. This also applied to assertions used as conditions.
115    
116    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
117        assertion subpattern, including such a pattern used as a condition,
118        unpredictable results occurred, instead of the error return
119        PCRE_ERROR_DFA_UITEM.
120    
121    5.  The C++ GlobalReplace function was not working like Perl for the special
122        situation when an empty string is matched. It now does the fancy magic
123        stuff that is necessary.
124    
125    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
126        removed. (These were left over from very, very early versions of PCRE.)
127    
128    7.  Some cosmetic changes to the code to make life easier when compiling it
129        as part of something else:
130    
131        (a) Change DEBUG to PCRE_DEBUG.
132    
133        (b) In pcre_compile(), rename the member of the "branch_chain" structure
134            called "current" as "current_branch", to prevent a collision with the
135            Linux macro when compiled as a kernel module.
136    
137        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
138            prevent a collision with the Linux macro when compiled as a kernel
139            module.
140    
141    8.  In pcre_compile() there are some checks for integer overflows that used to
142        cast potentially large values to (double). This has been changed to that
143        when building, a check for int64_t is made, and if it is found, it is used
144        instead, thus avoiding the use of floating point arithmetic. (There is no
145        other use of FP in PCRE.) If int64_t is not found, the fallback is to
146        double.
147    
148    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
149        2005 (difference between two addresses compared to an unsigned value).
150    
151    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
152        custom one, because of the following reported problem in Windows:
153    
154          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
155              under Win32.
156          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
157              therefore missing the function definition.
158          - The compiler thus generates a "C" signature for the test function.
159          - The linker fails to find the "C" function.
160          - PCRE fails to configure if asked to do so against libbz2.
161    
162    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
163        messages were output:
164    
165          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
166          rerunning libtoolize, to keep the correct libtool macros in-tree.
167          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
168    
169        I have done both of these things.
170    
171    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
172        most of the time, it *can* run out if it is given a pattern that contains a
173        runaway infinite recursion. I updated the discussion in the pcrestack man
174        page.
175    
176    13. Now that we have gone to the x.xx style of version numbers, the minor
177        version may start with zero. Using 08 or 09 is a bad idea because users
178        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
179        interpreted as invalid octal numbers. I've updated the previous comment in
180        configure.ac, and also added a check that gives an error if 08 or 09 are
181        used.
182    
183    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
184        causing partial matching to fail when the end of the subject matched \W
185        in a UTF-8 pattern where \W was quantified with a minimum of 3.
186    
187    15. There were some discrepancies between the declarations in pcre_internal.h
188        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
189        their definitions. The declarations used "const uschar *" and the
190        definitions used USPTR. Even though USPTR is normally defined as "const
191        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
192        reported that: "This difference in casting confuses some C++ compilers, for
193        example, SunCC recognizes above declarations as different functions and
194        generates broken code for hbpcre." I have changed the declarations to use
195        USPTR.
196    
197    16. GNU libtool is named differently on some systems. The autogen.sh script now
198        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
199        (FreeBSD).
200    
201    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
202        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
203        comment: "Figure out how to create a longlong from a string: strtoll and
204        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
205        instance, but it only takes 2 args instead of 3!"
206    
207    18. A subtle bug concerned with back references has been fixed by a change of
208        specification, with a corresponding code fix. A pattern such as
209        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
210        refers, was giving matches when it shouldn't. For example, xa=xaaa would
211        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
212        same bug. Such groups have to be quantified to be useful, or contained
213        inside another quantified group. (If there's no repetition, the reference
214        can never match.) The problem arises because, having left the group and
215        moved on to the rest of the pattern, a later failure that backtracks into
216        the group uses the captured value from the final iteration of the group
217        rather than the correct earlier one. I have fixed this in PCRE by forcing
218        any group that contains a reference to itself to be an atomic group; that
219        is, there cannot be any backtracking into it once it has completed. This is
220        similar to recursive and subroutine calls.
221    
222    
223    Version 8.00 19-Oct-09
224  ----------------------  ----------------------
225    
226  1.  The table for translating pcre_compile() error codes into POSIX error codes  1.  The table for translating pcre_compile() error codes into POSIX error codes
# Line 58  Version 8.00 05-Oct-09 Line 277  Version 8.00 05-Oct-09
277  10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is  10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
278      synonymous with PCRE_PARTIAL, for backwards compatibility, and      synonymous with PCRE_PARTIAL, for backwards compatibility, and
279      PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,      PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
280      and may be more useful for multi-segment matching, especially with      and may be more useful for multi-segment matching.
     pcre_exec().  
281    
282  11. Partial matching with pcre_exec() is now more intuitive. A partial match  11. Partial matching with pcre_exec() is now more intuitive. A partial match
283      used to be given if ever the end of the subject was reached; now it is      used to be given if ever the end of the subject was reached; now it is

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