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

Diff of /code/trunk/ChangeLog

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

revision 93 by nigel, Sat Feb 24 21:41:42 2007 UTC revision 207 by ph10, Mon Aug 6 09:32:14 2007 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 7.3 05-Jul-07
5    ---------------------
6    
7     1. In the rejigging of the build system that eventually resulted in 7.1, the
8        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
9        brackets there is not right, since it causes compilers to look for an
10        installed pcre.h, not the version that is in the source that is being
11        compiled (which of course may be different). I have changed it back to:
12    
13          #include "pcre.h"
14    
15        I have a vague recollection that the change was concerned with compiling in
16        different directories, but in the new build system, that is taken care of
17        by the VPATH setting the Makefile.
18    
19     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
20        when the subject happened to end in the byte 0x85 (e.g. if the last
21        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
22        characters but of course it shouldn't be taken as a newline when it is part
23        of another character. The bug was that, for an unlimited repeat of . in
24        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
25        characters when looking for a newline.
26    
27     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
28    
29     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
30        in debug output.
31    
32     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
33        long printing in the pcrecpp unittest when running under MinGW.
34    
35     6. ESC_K was left out of the EBCDIC table.
36    
37     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
38        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
39        limit also applies to "virtual nesting" when a pattern is recursive, and in
40        this case 1000 isn't so big. I have been able to remove this limit at the
41        expense of backing off one optimization in certain circumstances. Normally,
42        when pcre_exec() would call its internal match() function recursively and
43        immediately return the result unconditionally, it uses a "tail recursion"
44        feature to save stack. However, when a subpattern that can match an empty
45        string has an unlimited repetition quantifier, it no longer makes this
46        optimization. That gives it a stack frame in which to save the data for
47        checking that an empty string has been matched. Previously this was taken
48        from the 1000-entry workspace that had been reserved. So now there is no
49        explicit limit, but more stack is used.
50    
51     8. Applied Daniel's patches to solve problems with the import/export magic
52        syntax that is required for Windows, and which was going wrong for the
53        pcreposix and pcrecpp parts of the library. These were overlooked when this
54        problem was solved for the main library.
55    
56     9. There were some crude static tests to avoid integer overflow when computing
57        the size of patterns that contain repeated groups with explicit upper
58        limits. As the maximum quantifier is 65535, the maximum group length was
59        set at 30,000 so that the product of these two numbers did not overflow a
60        32-bit integer. However, it turns out that people want to use groups that
61        are longer than 30,000 bytes (though not repeat them that many times).
62        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
63        made it possible to implement the integer overflow checks in a much more
64        dynamic way, which I have now done. The artificial limitation on group
65        length has been removed - we now have only the limit on the total length of
66        the compiled pattern, which depends on the LINK_SIZE setting.
67    
68    10. Fixed a bug in the documentation for get/copy named substring when
69        duplicate names are permitted. If none of the named substrings are set, the
70        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
71        empty string.
72    
73    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
74        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
75        because the ] is interpreted as the first data character and the
76        terminating ] is not found. PCRE has been made compatible with Perl in this
77        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
78        cause memory overwriting.
79    
80    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
81        string has been matched (to stop an infinite loop). It was not recognizing
82        a conditional subpattern that could match an empty string if that
83        subpattern was within another subpattern. For example, it looped when
84        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
85        condition was not nested. This bug has been fixed.
86    
87    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
88        past the start of the subject in the presence of bytes with the top bit
89        set, for example "\x8aBCD".
90    
91    
92    Version 7.2 19-Jun-07
93    ---------------------
94    
95     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
96        which is apparently normally available under Windows.
97    
98     2. Re-jig the pcregrep tests with different newline settings in an attempt
99        to make them independent of the local environment's newline setting.
100    
101     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
102    
103     4. Some of the "internals" tests were previously cut out when the link size
104        was not 2, because the output contained actual offsets. The recent new
105        "Z" feature of pcretest means that these can be cut out, making the tests
106        usable with all link sizes.
107    
108     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
109        stack recursion. This gives a massive performance boost under BSD, but just
110        a small improvement under Linux. However, it saves one field in the frame
111        in all cases.
112    
113     6. Added more features from the forthcoming Perl 5.10:
114    
115        (a) (?-n) (where n is a string of digits) is a relative subroutine or
116            recursion call. It refers to the nth most recently opened parentheses.
117    
118        (b) (?+n) is also a relative subroutine call; it refers to the nth next
119            to be opened parentheses.
120    
121        (c) Conditions that refer to capturing parentheses can be specified
122            relatively, for example, (?(-2)... or (?(+3)...
123    
124        (d) \K resets the start of the current match so that everything before
125            is not part of it.
126    
127        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
128    
129        (f) \g{name} is another synonym - part of Perl 5.10's unification of
130            reference syntax.
131    
132        (g) (?| introduces a group in which the numbering of parentheses in each
133            alternative starts with the same number.
134    
135        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
136    
137     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
138        PCRE_INFO_JCHANGED.
139    
140     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
141        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
142        for detecting groups that can match an empty string.
143    
144     9. A pattern with a very large number of alternatives (more than several
145        hundred) was running out of internal workspace during the pre-compile
146        phase, where pcre_compile() figures out how much memory will be needed. A
147        bit of new cunning has reduced the workspace needed for groups with
148        alternatives. The 1000-alternative test pattern now uses 12 bytes of
149        workspace instead of running out of the 4096 that are available.
150    
151    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
152    
153    11. Applied patch from Google to remove an optimization that didn't quite work.
154        The report of the bug said:
155    
156          pcrecpp::RE("a*").FullMatch("aaa") matches, while
157          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
158          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
159    
160    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
161        it matched the wrong number of bytes.
162    
163    
164    Version 7.1 24-Apr-07
165    ---------------------
166    
167     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
168        that is more "standard", making use of automake and other Autotools. There
169        is some re-arrangement of the files and adjustment of comments consequent
170        on this.
171    
172     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
173        for recursive directory scanning broke on some systems because the files
174        are not scanned in any specific order and on different systems the order
175        was different. A call to "sort" has been inserted into RunGrepTest for the
176        approprate test as a short-term fix. In the longer term there may be an
177        alternative.
178    
179     3. I had an email from Eric Raymond about problems translating some of PCRE's
180        man pages to HTML (despite the fact that I distribute HTML pages, some
181        people do their own conversions for various reasons). The problems
182        concerned the use of low-level troff macros .br and .in. I have therefore
183        removed all such uses from the man pages (some were redundant, some could
184        be replaced by .nf/.fi pairs). The 132html script that I use to generate
185        HTML has been updated to handle .nf/.fi and to complain if it encounters
186        .br or .in.
187    
188     4. Updated comments in configure.ac that get placed in config.h.in and also
189        arranged for config.h to be included in the distribution, with the name
190        config.h.generic, for the benefit of those who have to compile without
191        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
192    
193     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
194        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
195        makevp.bat for the current PCRE, using the additional files
196        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
197    
198     6. A Windows user reported a minor discrepancy with test 2, which turned out
199        to be caused by a trailing space on an input line that had got lost in his
200        copy. The trailing space was an accident, so I've just removed it.
201    
202     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
203        that is needed.
204    
205     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
206        as "const" (a) because they are and (b) because it helps the PHP
207        maintainers who have recently made a script to detect big data structures
208        in the php code that should be moved to the .rodata section. I remembered
209        to update Builducptable as well, so it won't revert if ucptable.h is ever
210        re-created.
211    
212     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
213        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
214        order to be able to cut out the UTF-8 tables in the latter when UTF-8
215        support is not required. This saves 1.5-2K of code, which is important in
216        some applications.
217    
218        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
219        so as not to refer to the tables, even though these functions will never be
220        called when UTF-8 support is disabled. Otherwise there are problems with a
221        shared library.
222    
223    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
224    
225        (a) It was defining its arguments as char * instead of void *.
226    
227        (b) It was assuming that all moves were upwards in memory; this was true
228            a long time ago when I wrote it, but is no longer the case.
229    
230        The emulated memove() is provided for those environments that have neither
231        memmove() nor bcopy(). I didn't think anyone used it these days, but that
232        is clearly not the case, as these two bugs were recently reported.
233    
234    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
235        and Detrail to create the HTML documentation, the .txt form of the man
236        pages, and it removes trailing spaces from listed files. It also creates
237        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
238        case, it wraps all the #defines with #ifndefs. This script should be run
239        before "make dist".
240    
241    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
242        with Unicode property support.
243    
244        (a) For a maximizing quantifier, if the two different cases of the
245            character were of different lengths in their UTF-8 codings (there are
246            some cases like this - I found 11), and the matching function had to
247            back up over a mixture of the two cases, it incorrectly assumed they
248            were both the same length.
249    
250        (b) When PCRE was configured to use the heap rather than the stack for
251            recursion during matching, it was not correctly preserving the data for
252            the other case of a UTF-8 character when checking ahead for a match
253            while processing a minimizing repeat. If the check also involved
254            matching a wide character, but failed, corruption could cause an
255            erroneous result when trying to check for a repeat of the original
256            character.
257    
258    13. Some tidying changes to the testing mechanism:
259    
260        (a) The RunTest script now detects the internal link size and whether there
261            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
262            values substituted by "configure". (The RunGrepTest script already did
263            this for UTF-8.) The configure.ac script no longer substitutes the
264            relevant variables.
265    
266        (b) The debugging options /B and /D in pcretest show the compiled bytecode
267            with length and offset values. This means that the output is different
268            for different internal link sizes. Test 2 is skipped for link sizes
269            other than 2 because of this, bypassing the problem. Unfortunately,
270            there was also a test in test 3 (the locale tests) that used /B and
271            failed for link sizes other than 2. Rather than cut the whole test out,
272            I have added a new /Z option to pcretest that replaces the length and
273            offset values with spaces. This is now used to make test 3 independent
274            of link size. (Test 2 will be tidied up later.)
275    
276    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
277        segmentation fault instead of returning the appropriate error message.
278    
279    15. In multiline mode when the newline sequence was set to "any", the pattern
280        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
281        This doesn't seem right; it now treats the CRLF combination as the line
282        ending, and so does not match in that case. It's only a pattern such as ^$
283        that would hit this one: something like ^ABC$ would have failed after \r
284        and then tried again after \r\n.
285    
286    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
287        in an attempt to make files that differ only in their line terminators
288        compare equal. This works on Linux.
289    
290    17. Under certain error circumstances pcregrep might try to free random memory
291        as it exited. This is now fixed, thanks to valgrind.
292    
293    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
294        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
295        was because its rules for how to advance for /g after matching an empty
296        string at the end of a line did not allow for this case. They now check for
297        it specially.
298    
299    20. pcretest is supposed to handle patterns and data of any length, by
300        extending its buffers when necessary. It was getting this wrong when the
301        buffer for a data line had to be extended.
302    
303    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
304        CRLF as a newline sequence.
305    
306    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
307        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
308        I have nevertheless tidied it up.
309    
310    23. Added some casts to kill warnings from HP-UX ia64 compiler.
311    
312    24. Added a man page for pcre-config.
313    
314    
315  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
316  ---------------------  ---------------------
317    

Legend:
Removed from v.93  
changed lines
  Added in v.207

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12