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revision 476 by ph10, Sun Jan 3 15:37:24 2010 UTC revision 551 by ph10, Sun Oct 10 17:33:07 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 8.01 11-Dec-09  Version 8.11 10-Oct-2010
5  ----------------------  ------------------------
6    
7    1.  (*THEN) was not working properly if there were untried alternatives prior
8        to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9        backtracked to try for "b" instead of moving to the next alternative branch
10        at the same level (in this case, to look for "c"). The Perl documentation
11        is clear that when (*THEN) is backtracked onto, it goes to the "next
12        alternative in the innermost enclosing group".
13    
14    2.  (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15        such as   (A(*COMMIT)B(*THEN)C|D)  any failure after matching A should
16        result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17        (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18        (*THEN).
19    
20    
21    Version 8.10 25-Jun-2010
22    ------------------------
23    
24    1.  Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
25        THEN.
26    
27    2.  (*ACCEPT) was not working when inside an atomic group.
28    
29    3.  Inside a character class, \B is treated as a literal by default, but
30        faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
31        causes the error). The code is unchanged, but I tidied the documentation.
32    
33    4.  Inside a character class, PCRE always treated \R and \X as literals,
34        whereas Perl faults them if its -w option is set. I have changed PCRE so
35        that it faults them when PCRE_EXTRA is set.
36    
37    5.  Added support for \N, which always matches any character other than
38        newline. (It is the same as "." when PCRE_DOTALL is not set.)
39    
40    6.  When compiling pcregrep with newer versions of gcc which may have
41        FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
42        declared with attribute warn_unused_result" were given. Just casting the
43        result to (void) does not stop the warnings; a more elaborate fudge is
44        needed. I've used a macro to implement this.
45    
46    7.  Minor change to pcretest.c to avoid a compiler warning.
47    
48    8.  Added four artifical Unicode properties to help with an option to make
49        \s etc use properties (see next item). The new properties are: Xan
50        (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
51    
52    9.  Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
53        use Unicode properties. (*UCP) at the start of a pattern can be used to set
54        this option. Modified pcretest to add /W to test this facility. Added
55        REG_UCP to make it available via the POSIX interface.
56    
57    10. Added --line-buffered to pcregrep.
58    
59    11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
60        studied, and the match started with a letter with a code point greater than
61        127 whose first byte was different to the first byte of the other case of
62        the letter, the other case of this starting letter was not recognized
63        (#976).
64    
65    12. If a pattern that was studied started with a repeated Unicode property
66        test, for example, \p{Nd}+, there was the theoretical possibility of
67        setting up an incorrect bitmap of starting bytes, but fortunately it could
68        not have actually happened in practice until change 8 above was made (it
69        added property types that matched character-matching opcodes).
70    
71    13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
72        possible starting bytes for non-anchored patterns.
73    
74    14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
75        \R, and also a number of cases that involve Unicode properties, both
76        explicit and implicit when PCRE_UCP is set.
77    
78    15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
79        input, it could crash or give wrong results if characters with values
80        greater than 0xc0 were present in the subject string. (Detail: it assumed
81        UTF-8 input when processing these items.)
82    
83    16. Added a lot of (int) casts to avoid compiler warnings in systems where
84        size_t is 64-bit (#991).
85    
86    17. Added a check for running out of memory when PCRE is compiled with
87        --disable-stack-for-recursion (#990).
88    
89    18. If the last data line in a file for pcretest does not have a newline on
90        the end, a newline was missing in the output.
91    
92    19. The default pcre_chartables.c file recognizes only ASCII characters (values
93        less than 128) in its various bitmaps. However, there is a facility for
94        generating tables according to the current locale when PCRE is compiled. It
95        turns out that in some environments, 0x85 and 0xa0, which are Unicode space
96        characters, are recognized by isspace() and therefore were getting set in
97        these tables, and indeed these tables seem to approximate to ISO 8859. This
98        caused a problem in UTF-8 mode when pcre_study() was used to create a list
99        of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
100        which of course cannot start UTF-8 characters. I have changed the code so
101        that only real ASCII characters (less than 128) and the correct starting
102        bytes for UTF-8 encodings are set for characters greater than 127 when in
103        UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
104        altogether.)
105    
106    20. Added the /T option to pcretest so as to be able to run tests with non-
107        standard character tables, thus making it possible to include the tests
108        used for 19 above in the standard set of tests.
109    
110    21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
111        reference to a subpattern the other side of a comment that contains an
112        opening parenthesis caused either an internal compiling error, or a
113        reference to the wrong subpattern.
114    
115    
116    Version 8.02 19-Mar-2010
117    ------------------------
118    
119    1.  The Unicode data tables have been updated to Unicode 5.2.0.
120    
121    2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
122        configured.
123    
124    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
125        original author of that file, following a query about its status.
126    
127    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
128        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
129    
130    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
131        quantifier applied to a forward-referencing subroutine call, could compile
132        incorrect code or give the error "internal error: previously-checked
133        referenced subpattern not found".
134    
135    6.  Both MS Visual Studio and Symbian OS have problems with initializing
136        variables to point to external functions. For these systems, therefore,
137        pcre_malloc etc. are now initialized to local functions that call the
138        relevant global functions.
139    
140    7.  There were two entries missing in the vectors called coptable and poptable
141        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
142        I've fixed the data, and added a kludgy way of testing at compile time that
143        the lengths are correct (equal to the number of opcodes).
144    
145    8.  Following on from 7, I added a similar kludge to check the length of the
146        eint vector in pcreposix.c.
147    
148    9.  Error texts for pcre_compile() are held as one long string to avoid too
149        much relocation at load time. To find a text, the string is searched,
150        counting zeros. There was no check for running off the end of the string,
151        which could happen if a new error number was added without updating the
152        string.
153    
154    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
155    
156    11. \K was not working if it appeared in an atomic group or in a group that
157        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
158        \K is "not well defined" if used in an assertion. PCRE now accepts it if
159        the assertion is positive, but not if it is negative.
160    
161    12. Change 11 fortuitously reduced the size of the stack frame used in the
162        "match()" function of pcre_exec.c by one pointer. Forthcoming
163        implementation of support for (*MARK) will need an extra pointer on the
164        stack; I have reserved it now, so that the stack frame size does not
165        decrease.
166    
167    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
168        item in branch that calls a recursion is a subroutine call - as in the
169        second branch in the above example - was incorrectly given the compile-
170        time error "recursive call could loop indefinitely" because pcre_compile()
171        was not correctly checking the subroutine for matching a non-empty string.
172    
173    14. The checks for overrunning compiling workspace could trigger after an
174        overrun had occurred. This is a "should never occur" error, but it can be
175        triggered by pathological patterns such as hundreds of nested parentheses.
176        The checks now trigger 100 bytes before the end of the workspace.
177    
178    15. Fix typo in configure.ac: "srtoq" should be "strtoq".
179    
180    
181    Version 8.01 19-Jan-2010
182    ------------------------
183    
184  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
185      particular, this includes all (DEFINE) patterns), a call to pcre_study()      particular, this includes all (*DEFINE) patterns), a call to pcre_study()
186      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
187      subpatterns).      subpatterns). This could cause incorrect "no match" results.
188    
189  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
190      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 203  Version 8.01 11-Dec-09
203      assertion subpattern, including such a pattern used as a condition,      assertion subpattern, including such a pattern used as a condition,
204      unpredictable results occurred, instead of the error return      unpredictable results occurred, instead of the error return
205      PCRE_ERROR_DFA_UITEM.      PCRE_ERROR_DFA_UITEM.
206    
207  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
208      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
209      stuff that is necessary.      stuff that is necessary.
210    
211  6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been  6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
212      removed. (These were left over from very, very early versions of PCRE.)      removed. (These were left over from very, very early versions of PCRE.)
213    
214  7.  Some cosmetic changes to the code to make life easier when compiling it  7.  Some cosmetic changes to the code to make life easier when compiling it
215      as part of something else:      as part of something else:
216    
217      (a) Change DEBUG to PCRE_DEBUG.      (a) Change DEBUG to PCRE_DEBUG.
218    
219      (b) In pcre_compile(), rename the member of the "branch_chain" structure      (b) In pcre_compile(), rename the member of the "branch_chain" structure
220          called "current" as "current_branch", to prevent a collision with the          called "current" as "current_branch", to prevent a collision with the
221          Linux macro when compiled as a kernel module.          Linux macro when compiled as a kernel module.
222    
223      (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to      (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
224          prevent a collision with the Linux macro when compiled as a kernel          prevent a collision with the Linux macro when compiled as a kernel
225          module.          module.
226    
227  8.  In pcre_compile() there are some checks for integer overflows that used to  8.  In pcre_compile() there are some checks for integer overflows that used to
228      cast potentially large values to (double). This has been changed to that      cast potentially large values to (double). This has been changed to that
229      when building, a check for int64_t is made, and if it is found, it is used      when building, a check for int64_t is made, and if it is found, it is used
230      instead, thus avoiding the use of floating point arithmetic. (There is no      instead, thus avoiding the use of floating point arithmetic. (There is no
231      other use of FP in PCRE.) If int64_t is not found, the fallback is to      other use of FP in PCRE.) If int64_t is not found, the fallback is to
232      double.      double.
233    
234  9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express  9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
235      2005 (difference between two addresses compared to an unsigned value).      2005 (difference between two addresses compared to an unsigned value).
236    
237    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
238        custom one, because of the following reported problem in Windows:
239    
240          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
241              under Win32.
242          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
243              therefore missing the function definition.
244          - The compiler thus generates a "C" signature for the test function.
245          - The linker fails to find the "C" function.
246          - PCRE fails to configure if asked to do so against libbz2.
247    
248    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
249        messages were output:
250    
251          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
252          rerunning libtoolize, to keep the correct libtool macros in-tree.
253          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
254    
255        I have done both of these things.
256    
257    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
258        most of the time, it *can* run out if it is given a pattern that contains a
259        runaway infinite recursion. I updated the discussion in the pcrestack man
260        page.
261    
262    13. Now that we have gone to the x.xx style of version numbers, the minor
263        version may start with zero. Using 08 or 09 is a bad idea because users
264        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
265        interpreted as invalid octal numbers. I've updated the previous comment in
266        configure.ac, and also added a check that gives an error if 08 or 09 are
267        used.
268    
269    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
270        causing partial matching to fail when the end of the subject matched \W
271        in a UTF-8 pattern where \W was quantified with a minimum of 3.
272    
273    15. There were some discrepancies between the declarations in pcre_internal.h
274        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
275        their definitions. The declarations used "const uschar *" and the
276        definitions used USPTR. Even though USPTR is normally defined as "const
277        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
278        reported that: "This difference in casting confuses some C++ compilers, for
279        example, SunCC recognizes above declarations as different functions and
280        generates broken code for hbpcre." I have changed the declarations to use
281        USPTR.
282    
283    16. GNU libtool is named differently on some systems. The autogen.sh script now
284        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
285        (FreeBSD).
286    
287    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
288        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
289        comment: "Figure out how to create a longlong from a string: strtoll and
290        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
291        instance, but it only takes 2 args instead of 3!"
292    
293    18. A subtle bug concerned with back references has been fixed by a change of
294        specification, with a corresponding code fix. A pattern such as
295        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
296        refers, was giving matches when it shouldn't. For example, xa=xaaa would
297        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
298        same bug. Such groups have to be quantified to be useful, or contained
299        inside another quantified group. (If there's no repetition, the reference
300        can never match.) The problem arises because, having left the group and
301        moved on to the rest of the pattern, a later failure that backtracks into
302        the group uses the captured value from the final iteration of the group
303        rather than the correct earlier one. I have fixed this in PCRE by forcing
304        any group that contains a reference to itself to be an atomic group; that
305        is, there cannot be any backtracking into it once it has completed. This is
306        similar to recursive and subroutine calls.
307    
308    
309  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09

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