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revision 111 by ph10, Thu Mar 8 16:53:09 2007 UTC revision 212 by ph10, Thu Aug 9 11:16:34 2007 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 05-Mar-07  Version 7.3 09-Aug-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    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
92        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
93    
94    14. Optimized (?!) to (*FAIL).
95    
96    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
97        This restricts code points to be within the range 0 to 0x10FFFF, excluding
98        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
99        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
100        does: it's just the validity check that is more restrictive.
101    
102    
103    Version 7.2 19-Jun-07
104    ---------------------
105    
106     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
107        which is apparently normally available under Windows.
108    
109     2. Re-jig the pcregrep tests with different newline settings in an attempt
110        to make them independent of the local environment's newline setting.
111    
112     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
113    
114     4. Some of the "internals" tests were previously cut out when the link size
115        was not 2, because the output contained actual offsets. The recent new
116        "Z" feature of pcretest means that these can be cut out, making the tests
117        usable with all link sizes.
118    
119     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
120        stack recursion. This gives a massive performance boost under BSD, but just
121        a small improvement under Linux. However, it saves one field in the frame
122        in all cases.
123    
124     6. Added more features from the forthcoming Perl 5.10:
125    
126        (a) (?-n) (where n is a string of digits) is a relative subroutine or
127            recursion call. It refers to the nth most recently opened parentheses.
128    
129        (b) (?+n) is also a relative subroutine call; it refers to the nth next
130            to be opened parentheses.
131    
132        (c) Conditions that refer to capturing parentheses can be specified
133            relatively, for example, (?(-2)... or (?(+3)...
134    
135        (d) \K resets the start of the current match so that everything before
136            is not part of it.
137    
138        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
139    
140        (f) \g{name} is another synonym - part of Perl 5.10's unification of
141            reference syntax.
142    
143        (g) (?| introduces a group in which the numbering of parentheses in each
144            alternative starts with the same number.
145    
146        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
147    
148     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
149        PCRE_INFO_JCHANGED.
150    
151     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
152        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
153        for detecting groups that can match an empty string.
154    
155     9. A pattern with a very large number of alternatives (more than several
156        hundred) was running out of internal workspace during the pre-compile
157        phase, where pcre_compile() figures out how much memory will be needed. A
158        bit of new cunning has reduced the workspace needed for groups with
159        alternatives. The 1000-alternative test pattern now uses 12 bytes of
160        workspace instead of running out of the 4096 that are available.
161    
162    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
163    
164    11. Applied patch from Google to remove an optimization that didn't quite work.
165        The report of the bug said:
166    
167          pcrecpp::RE("a*").FullMatch("aaa") matches, while
168          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
169          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
170    
171    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
172        it matched the wrong number of bytes.
173    
174    
175    Version 7.1 24-Apr-07
176  ---------------------  ---------------------
177    
178   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
179      that is more "standard", making use of automake and other autotools. There      that is more "standard", making use of automake and other Autotools. There
180      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
181      on this.      on this.
182    
# Line 21  Version 7.1 05-Mar-07 Line 192  Version 7.1 05-Mar-07
192      people do their own conversions for various reasons). The problems      people do their own conversions for various reasons). The problems
193      concerned the use of low-level troff macros .br and .in. I have therefore      concerned the use of low-level troff macros .br and .in. I have therefore
194      removed all such uses from the man pages (some were redundant, some could      removed all such uses from the man pages (some were redundant, some could
195      be replaced by .nf/.fi pairs). The maintain/132html script that I use to      be replaced by .nf/.fi pairs). The 132html script that I use to generate
196      generate HTML has been updated to handle .nf/.fi and to complain if it      HTML has been updated to handle .nf/.fi and to complain if it encounters
197      encounters .br or .in.      .br or .in.
198    
199   4. Updated comments in configure.ac that get placed in config.h.in and also   4. Updated comments in configure.ac that get placed in config.h.in and also
200      arranged for config.h to be included in the distribution, with the name      arranged for config.h to be included in the distribution, with the name
201      config.h.generic, for the benefit of those who have to compile without      config.h.generic, for the benefit of those who have to compile without
202      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
203    
204   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan   5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
205      Weber: (1) pcre_internal.h was missing some function renames; (2) updated      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
206      makevp.bat for the current PCRE, using the additional files !compile.txt,      makevp.bat for the current PCRE, using the additional files
207      !linklib.txt, and pcregexp.pas.      makevp_c.txt, makevp_l.txt, and pcregexp.pas.
208    
209   6. A Windows user reported a minor discrepancy with test 2, which turned out   6. A Windows user reported a minor discrepancy with test 2, which turned out
210      to be caused by a trailing space on an input line that had got lost in his      to be caused by a trailing space on an input line that had got lost in his
# Line 60  Version 7.1 05-Mar-07 Line 231  Version 7.1 05-Mar-07
231      called when UTF-8 support is disabled. Otherwise there are problems with a      called when UTF-8 support is disabled. Otherwise there are problems with a
232      shared library.      shared library.
233    
234  10. The emulated memmove() function in pcre_internal.h (provided for those  10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
235      environments that have neither memmove() nor bcopy()) was defining its  
236      arguments as char * instead of void *.      (a) It was defining its arguments as char * instead of void *.
237    
238        (b) It was assuming that all moves were upwards in memory; this was true
239            a long time ago when I wrote it, but is no longer the case.
240    
241        The emulated memove() is provided for those environments that have neither
242        memmove() nor bcopy(). I didn't think anyone used it these days, but that
243        is clearly not the case, as these two bugs were recently reported.
244    
245  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
246      and Detrail to create the HTML documentation, the .txt form of the man      and Detrail to create the HTML documentation, the .txt form of the man
247      pages, and it removes trailing spaces from listed files. It also creates      pages, and it removes trailing spaces from listed files. It also creates
248      pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter      pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
249      case, it wraps all the #defines with #ifndefs. This script should be run      case, it wraps all the #defines with #ifndefs. This script should be run
250      before "make dist".      before "make dist".
251    
252    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
253        with Unicode property support.
254    
255        (a) For a maximizing quantifier, if the two different cases of the
256            character were of different lengths in their UTF-8 codings (there are
257            some cases like this - I found 11), and the matching function had to
258            back up over a mixture of the two cases, it incorrectly assumed they
259            were both the same length.
260    
261        (b) When PCRE was configured to use the heap rather than the stack for
262            recursion during matching, it was not correctly preserving the data for
263            the other case of a UTF-8 character when checking ahead for a match
264            while processing a minimizing repeat. If the check also involved
265            matching a wide character, but failed, corruption could cause an
266            erroneous result when trying to check for a repeat of the original
267            character.
268    
269    13. Some tidying changes to the testing mechanism:
270    
271        (a) The RunTest script now detects the internal link size and whether there
272            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
273            values substituted by "configure". (The RunGrepTest script already did
274            this for UTF-8.) The configure.ac script no longer substitutes the
275            relevant variables.
276    
277        (b) The debugging options /B and /D in pcretest show the compiled bytecode
278            with length and offset values. This means that the output is different
279            for different internal link sizes. Test 2 is skipped for link sizes
280            other than 2 because of this, bypassing the problem. Unfortunately,
281            there was also a test in test 3 (the locale tests) that used /B and
282            failed for link sizes other than 2. Rather than cut the whole test out,
283            I have added a new /Z option to pcretest that replaces the length and
284            offset values with spaces. This is now used to make test 3 independent
285            of link size. (Test 2 will be tidied up later.)
286    
287    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
288        segmentation fault instead of returning the appropriate error message.
289    
290    15. In multiline mode when the newline sequence was set to "any", the pattern
291        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
292        This doesn't seem right; it now treats the CRLF combination as the line
293        ending, and so does not match in that case. It's only a pattern such as ^$
294        that would hit this one: something like ^ABC$ would have failed after \r
295        and then tried again after \r\n.
296    
297    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
298        in an attempt to make files that differ only in their line terminators
299        compare equal. This works on Linux.
300    
301    17. Under certain error circumstances pcregrep might try to free random memory
302        as it exited. This is now fixed, thanks to valgrind.
303    
304    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
305        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
306        was because its rules for how to advance for /g after matching an empty
307        string at the end of a line did not allow for this case. They now check for
308        it specially.
309    
310    20. pcretest is supposed to handle patterns and data of any length, by
311        extending its buffers when necessary. It was getting this wrong when the
312        buffer for a data line had to be extended.
313    
314    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
315        CRLF as a newline sequence.
316    
317    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
318        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
319        I have nevertheless tidied it up.
320    
321    23. Added some casts to kill warnings from HP-UX ia64 compiler.
322    
323    24. Added a man page for pcre-config.
324    
325    
326  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
327  ---------------------  ---------------------

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