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revision 474 by ph10, Sat Jan 2 16:30:46 2010 UTC revision 532 by ph10, Tue Jun 1 16:21:42 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 (see next item). The new properties are: Xan
33        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
34    
35    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36        use Unicode properties. (*UCP) at the start of a pattern can be used to set
37        this option. Modified pcretest to add /W to test this facility. Added
38        REG_UCP to make it available via the POSIX interface.
39    
40    10. Added --line-buffered to pcregrep.
41    
42    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43        studied, and the match started with a letter with a code point greater than
44        127 whose first byte was different to the first byte of the other case of
45        the letter, the other case of this starting letter was not recognized.
46    
47    12. pcreposix.c included pcre.h before including pcre_internal.h. This caused a
48        conflict in the definition of PCRE_EXP_DECL. I have removed the include of
49        pcre.h as pcre_internal.h includes pcre.h itself. (This may be a bit of
50        historical tidying that never got done.)
51    
52    13. If a pattern that was studied started with a repeated Unicode property
53        test, for example, \p{Nd}+, there was the theoretical possibility of
54        setting up an incorrect bitmap of starting bytes, but fortunately it could
55        not have actually happened in practice until change 8 above was made (it
56        added property types that matched character-matching opcodes).
57    
58    14. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
59        possible starting bytes for non-anchored patterns.
60    
61    15. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
62        \R, and also a number of cases that involve Unicode properties, both
63        explicit and implicit when PCRE_UCP is set.
64    
65    16. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
66        input, it could crash or give wrong results if characters with values
67        greater than 0xc0 were present in the subject string. (Detail: it assumed
68        UTF-8 input when processing these items.)
69    
70    17. Added a lot of (int) casts to avoid compiler warnings in systems where
71        size_t is 64-bit.
72    
73    18. Added a check for running out of memory when PCRE is compiled with
74        --disable-stack-for-recursion.
75    
76    
77    
78    Version 8.02 19-Mar-2010
79    ------------------------
80    
81    1.  The Unicode data tables have been updated to Unicode 5.2.0.
82    
83    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
84        configured.
85    
86    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
87        original author of that file, following a query about its status.
88    
89    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
90        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
91    
92    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
93        quantifier applied to a forward-referencing subroutine call, could compile
94        incorrect code or give the error "internal error: previously-checked
95        referenced subpattern not found".
96    
97    6.  Both MS Visual Studio and Symbian OS have problems with initializing
98        variables to point to external functions. For these systems, therefore,
99        pcre_malloc etc. are now initialized to local functions that call the
100        relevant global functions.
101    
102    7.  There were two entries missing in the vectors called coptable and poptable
103        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
104        I've fixed the data, and added a kludgy way of testing at compile time that
105        the lengths are correct (equal to the number of opcodes).
106    
107    8.  Following on from 7, I added a similar kludge to check the length of the
108        eint vector in pcreposix.c.
109    
110    9.  Error texts for pcre_compile() are held as one long string to avoid too
111        much relocation at load time. To find a text, the string is searched,
112        counting zeros. There was no check for running off the end of the string,
113        which could happen if a new error number was added without updating the
114        string.
115    
116    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
117    
118    11. \K was not working if it appeared in an atomic group or in a group that
119        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
120        \K is "not well defined" if used in an assertion. PCRE now accepts it if
121        the assertion is positive, but not if it is negative.
122    
123    12. Change 11 fortuitously reduced the size of the stack frame used in the
124        "match()" function of pcre_exec.c by one pointer. Forthcoming
125        implementation of support for (*MARK) will need an extra pointer on the
126        stack; I have reserved it now, so that the stack frame size does not
127        decrease.
128    
129    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
130        item in branch that calls a recursion is a subroutine call - as in the
131        second branch in the above example - was incorrectly given the compile-
132        time error "recursive call could loop indefinitely" because pcre_compile()
133        was not correctly checking the subroutine for matching a non-empty string.
134    
135    14. The checks for overrunning compiling workspace could trigger after an
136        overrun had occurred. This is a "should never occur" error, but it can be
137        triggered by pathological patterns such as hundreds of nested parentheses.
138        The checks now trigger 100 bytes before the end of the workspace.
139    
140    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
141    
142    
143    Version 8.01 19-Jan-2010
144    ------------------------
145    
146  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
147      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
148      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
149      subpatterns).      subpatterns). This could cause incorrect "no match" results.
150    
151  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
152      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 165  Version 8.01 11-Dec-09
165      assertion subpattern, including such a pattern used as a condition,      assertion subpattern, including such a pattern used as a condition,
166      unpredictable results occurred, instead of the error return      unpredictable results occurred, instead of the error return
167      PCRE_ERROR_DFA_UITEM.      PCRE_ERROR_DFA_UITEM.
168    
169  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
170      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
171      stuff that is necessary.      stuff that is necessary.
172    
173    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
174        removed. (These were left over from very, very early versions of PCRE.)
175    
176    7.  Some cosmetic changes to the code to make life easier when compiling it
177        as part of something else:
178    
179        (a) Change DEBUG to PCRE_DEBUG.
180    
181        (b) In pcre_compile(), rename the member of the "branch_chain" structure
182            called "current" as "current_branch", to prevent a collision with the
183            Linux macro when compiled as a kernel module.
184    
185        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
186            prevent a collision with the Linux macro when compiled as a kernel
187            module.
188    
189    8.  In pcre_compile() there are some checks for integer overflows that used to
190        cast potentially large values to (double). This has been changed to that
191        when building, a check for int64_t is made, and if it is found, it is used
192        instead, thus avoiding the use of floating point arithmetic. (There is no
193        other use of FP in PCRE.) If int64_t is not found, the fallback is to
194        double.
195    
196    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
197        2005 (difference between two addresses compared to an unsigned value).
198    
199    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
200        custom one, because of the following reported problem in Windows:
201    
202          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
203              under Win32.
204          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
205              therefore missing the function definition.
206          - The compiler thus generates a "C" signature for the test function.
207          - The linker fails to find the "C" function.
208          - PCRE fails to configure if asked to do so against libbz2.
209    
210    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
211        messages were output:
212    
213          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
214          rerunning libtoolize, to keep the correct libtool macros in-tree.
215          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
216    
217        I have done both of these things.
218    
219    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
220        most of the time, it *can* run out if it is given a pattern that contains a
221        runaway infinite recursion. I updated the discussion in the pcrestack man
222        page.
223    
224    13. Now that we have gone to the x.xx style of version numbers, the minor
225        version may start with zero. Using 08 or 09 is a bad idea because users
226        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
227        interpreted as invalid octal numbers. I've updated the previous comment in
228        configure.ac, and also added a check that gives an error if 08 or 09 are
229        used.
230    
231    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
232        causing partial matching to fail when the end of the subject matched \W
233        in a UTF-8 pattern where \W was quantified with a minimum of 3.
234    
235    15. There were some discrepancies between the declarations in pcre_internal.h
236        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
237        their definitions. The declarations used "const uschar *" and the
238        definitions used USPTR. Even though USPTR is normally defined as "const
239        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
240        reported that: "This difference in casting confuses some C++ compilers, for
241        example, SunCC recognizes above declarations as different functions and
242        generates broken code for hbpcre." I have changed the declarations to use
243        USPTR.
244    
245    16. GNU libtool is named differently on some systems. The autogen.sh script now
246        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
247        (FreeBSD).
248    
249    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
250        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
251        comment: "Figure out how to create a longlong from a string: strtoll and
252        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
253        instance, but it only takes 2 args instead of 3!"
254    
255    18. A subtle bug concerned with back references has been fixed by a change of
256        specification, with a corresponding code fix. A pattern such as
257        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
258        refers, was giving matches when it shouldn't. For example, xa=xaaa would
259        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
260        same bug. Such groups have to be quantified to be useful, or contained
261        inside another quantified group. (If there's no repetition, the reference
262        can never match.) The problem arises because, having left the group and
263        moved on to the rest of the pattern, a later failure that backtracks into
264        the group uses the captured value from the final iteration of the group
265        rather than the correct earlier one. I have fixed this in PCRE by forcing
266        any group that contains a reference to itself to be an atomic group; that
267        is, there cannot be any backtracking into it once it has completed. This is
268        similar to recursive and subroutine calls.
269    
270    
271  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09

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