/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 184 by ph10, Tue Jun 19 13:26:46 2007 UTC revision 232 by ph10, Tue Sep 11 11:18:50 2007 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.2 19-June-07  Version 7.4 10-Sep-07
5    ---------------------
6    
7    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
8        means that a class such as [\s] counted as "explicit reference to CR or
9        LF". That isn't really right - the whole point of the change was to try to
10        help when there was an actual mention of one of the two characters. So now
11        the change happens only if \r or \n (or a literal CR or LF) character is
12        encountered.
13    
14    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
15        of both had grown to the point where there were only 3 bits left.
16        Fortunately, there was spare space in the data structure, and so I have
17        moved the internal flags into a new 16-bit field to free up more option
18        bits.
19    
20    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
21        but did not set the internal JCHANGED flag - either of these is enough to
22        control the way the "get" function works - but the PCRE_INFO_JCHANGED
23        facility is supposed to tell if (?J) was ever used, so now (?J) at the
24        start sets both bits.
25    
26    4.  Added options (at build time, compile time, exec time) to change \R from
27        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
28    
29    5.  doc/pcresyntax.html was missing from the distribution.
30    
31    
32    Version 7.3 28-Aug-07
33    ---------------------
34    
35     1. In the rejigging of the build system that eventually resulted in 7.1, the
36        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
37        brackets there is not right, since it causes compilers to look for an
38        installed pcre.h, not the version that is in the source that is being
39        compiled (which of course may be different). I have changed it back to:
40    
41          #include "pcre.h"
42    
43        I have a vague recollection that the change was concerned with compiling in
44        different directories, but in the new build system, that is taken care of
45        by the VPATH setting the Makefile.
46    
47     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
48        when the subject happened to end in the byte 0x85 (e.g. if the last
49        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
50        characters but of course it shouldn't be taken as a newline when it is part
51        of another character. The bug was that, for an unlimited repeat of . in
52        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
53        characters when looking for a newline.
54    
55     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
56    
57     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
58        in debug output.
59    
60     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
61        long printing in the pcrecpp unittest when running under MinGW.
62    
63     6. ESC_K was left out of the EBCDIC table.
64    
65     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
66        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
67        limit also applies to "virtual nesting" when a pattern is recursive, and in
68        this case 1000 isn't so big. I have been able to remove this limit at the
69        expense of backing off one optimization in certain circumstances. Normally,
70        when pcre_exec() would call its internal match() function recursively and
71        immediately return the result unconditionally, it uses a "tail recursion"
72        feature to save stack. However, when a subpattern that can match an empty
73        string has an unlimited repetition quantifier, it no longer makes this
74        optimization. That gives it a stack frame in which to save the data for
75        checking that an empty string has been matched. Previously this was taken
76        from the 1000-entry workspace that had been reserved. So now there is no
77        explicit limit, but more stack is used.
78    
79     8. Applied Daniel's patches to solve problems with the import/export magic
80        syntax that is required for Windows, and which was going wrong for the
81        pcreposix and pcrecpp parts of the library. These were overlooked when this
82        problem was solved for the main library.
83    
84     9. There were some crude static tests to avoid integer overflow when computing
85        the size of patterns that contain repeated groups with explicit upper
86        limits. As the maximum quantifier is 65535, the maximum group length was
87        set at 30,000 so that the product of these two numbers did not overflow a
88        32-bit integer. However, it turns out that people want to use groups that
89        are longer than 30,000 bytes (though not repeat them that many times).
90        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
91        made it possible to implement the integer overflow checks in a much more
92        dynamic way, which I have now done. The artificial limitation on group
93        length has been removed - we now have only the limit on the total length of
94        the compiled pattern, which depends on the LINK_SIZE setting.
95    
96    10. Fixed a bug in the documentation for get/copy named substring when
97        duplicate names are permitted. If none of the named substrings are set, the
98        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
99        empty string.
100    
101    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
102        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
103        because the ] is interpreted as the first data character and the
104        terminating ] is not found. PCRE has been made compatible with Perl in this
105        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
106        cause memory overwriting.
107    
108    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
109        string has been matched (to stop an infinite loop). It was not recognizing
110        a conditional subpattern that could match an empty string if that
111        subpattern was within another subpattern. For example, it looped when
112        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
113        condition was not nested. This bug has been fixed.
114    
115    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
116        past the start of the subject in the presence of bytes with the top bit
117        set, for example "\x8aBCD".
118    
119    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
120        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
121    
122    14. Optimized (?!) to (*FAIL).
123    
124    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
125        This restricts code points to be within the range 0 to 0x10FFFF, excluding
126        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
127        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
128        does: it's just the validity check that is more restrictive.
129    
130    16. Inserted checks for integer overflows during escape sequence (backslash)
131        processing, and also fixed erroneous offset values for syntax errors during
132        backslash processing.
133    
134    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
135        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
136    
137    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
138        caused an overrun.
139    
140    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
141        something other than just ASCII characters) inside a group that had an
142        unlimited repeat caused a loop at compile time (while checking to see
143        whether the group could match an empty string).
144    
145    20. Debugging a pattern containing \p or \P could cause a crash. For example,
146        [\P{Any}] did so. (Error in the code for printing property names.)
147    
148    21. An orphan \E inside a character class could cause a crash.
149    
150    22. A repeated capturing bracket such as (A)? could cause a wild memory
151        reference during compilation.
152    
153    23. There are several functions in pcre_compile() that scan along a compiled
154        expression for various reasons (e.g. to see if it's fixed length for look
155        behind). There were bugs in these functions when a repeated \p or \P was
156        present in the pattern. These operators have additional parameters compared
157        with \d, etc, and these were not being taken into account when moving along
158        the compiled data. Specifically:
159    
160        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
161            length.
162    
163        (b) An item such as \pL+ within a repeated group could cause crashes or
164            loops.
165    
166        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
167            "reference to non-existent subpattern" error.
168    
169        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
170    
171    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
172        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
173    
174    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
175    
176    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
177        character were causing crashes (broken optimization).
178    
179    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
180        \p or \P) caused a compile-time loop.
181    
182    28. More problems have arisen in unanchored patterns when CRLF is a valid line
183        break. For example, the unstudied pattern [\r\n]A does not match the string
184        "\r\nA" because change 7.0/46 below moves the current point on by two
185        characters after failing to match at the start. However, the pattern \nA
186        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
187        the same is true. There doesn't seem any very clean way out of this, but
188        what I have chosen to do makes the common cases work: PCRE now takes note
189        of whether there can be an explicit match for \r or \n anywhere in the
190        pattern, and if so, 7.0/46 no longer applies. As part of this change,
191        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
192        pattern has explicit CR or LF references.
193    
194    29. Added (*CR) etc for changing newline setting at start of pattern.
195    
196    
197    Version 7.2 19-Jun-07
198  ---------------------  ---------------------
199    
200   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,   1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
# Line 68  Version 7.2 19-June-07 Line 261  Version 7.2 19-June-07
261        pcrecpp::RE("a*").FullMatch("aaa") matches, while        pcrecpp::RE("a*").FullMatch("aaa") matches, while
262        pcrecpp::RE("a*?").FullMatch("aaa") does not, and        pcrecpp::RE("a*?").FullMatch("aaa") does not, and
263        pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.        pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
264    
265  12. If \p or \P was used in non-UTF-8 mode on a character greater than 127  12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
266      it matched the wrong number of bytes.      it matched the wrong number of bytes.
267    
268    
269  Version 7.1 24-Apr-07  Version 7.1 24-Apr-07

Legend:
Removed from v.184  
changed lines
  Added in v.232

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12