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revision 115 by ph10, Fri Mar 9 12:23:37 2007 UTC revision 206 by ph10, Fri Aug 3 14:53:04 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 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    
88    Version 7.2 19-Jun-07
89    ---------------------
90    
91     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
92        which is apparently normally available under Windows.
93    
94     2. Re-jig the pcregrep tests with different newline settings in an attempt
95        to make them independent of the local environment's newline setting.
96    
97     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
98    
99     4. Some of the "internals" tests were previously cut out when the link size
100        was not 2, because the output contained actual offsets. The recent new
101        "Z" feature of pcretest means that these can be cut out, making the tests
102        usable with all link sizes.
103    
104     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
105        stack recursion. This gives a massive performance boost under BSD, but just
106        a small improvement under Linux. However, it saves one field in the frame
107        in all cases.
108    
109     6. Added more features from the forthcoming Perl 5.10:
110    
111        (a) (?-n) (where n is a string of digits) is a relative subroutine or
112            recursion call. It refers to the nth most recently opened parentheses.
113    
114        (b) (?+n) is also a relative subroutine call; it refers to the nth next
115            to be opened parentheses.
116    
117        (c) Conditions that refer to capturing parentheses can be specified
118            relatively, for example, (?(-2)... or (?(+3)...
119    
120        (d) \K resets the start of the current match so that everything before
121            is not part of it.
122    
123        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
124    
125        (f) \g{name} is another synonym - part of Perl 5.10's unification of
126            reference syntax.
127    
128        (g) (?| introduces a group in which the numbering of parentheses in each
129            alternative starts with the same number.
130    
131        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
132    
133     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
134        PCRE_INFO_JCHANGED.
135    
136     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
137        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
138        for detecting groups that can match an empty string.
139    
140     9. A pattern with a very large number of alternatives (more than several
141        hundred) was running out of internal workspace during the pre-compile
142        phase, where pcre_compile() figures out how much memory will be needed. A
143        bit of new cunning has reduced the workspace needed for groups with
144        alternatives. The 1000-alternative test pattern now uses 12 bytes of
145        workspace instead of running out of the 4096 that are available.
146    
147    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
148    
149    11. Applied patch from Google to remove an optimization that didn't quite work.
150        The report of the bug said:
151    
152          pcrecpp::RE("a*").FullMatch("aaa") matches, while
153          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
154          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
155    
156    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
157        it matched the wrong number of bytes.
158    
159    
160    Version 7.1 24-Apr-07
161  ---------------------  ---------------------
162    
163   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
164      that is more "standard", making use of automake and other autotools. There      that is more "standard", making use of automake and other Autotools. There
165      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
166      on this.      on this.
167    
# Line 26  Version 7.1 05-Mar-07 Line 182  Version 7.1 05-Mar-07
182      .br or .in.      .br or .in.
183    
184   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
185      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
186      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
187      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).      Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
188    
189   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
190      Weber: (1) pcre_internal.h was missing some function renames; (2) updated      Weber: (1) pcre_internal.h was missing some function renames; (2) updated
191      makevp.bat for the current PCRE, using the additional files !compile.txt,      makevp.bat for the current PCRE, using the additional files
192      !linklib.txt, and pcregexp.pas.      makevp_c.txt, makevp_l.txt, and pcregexp.pas.
193    
194   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
195      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 216  Version 7.1 05-Mar-07
216      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
217      shared library.      shared library.
218    
219  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:
220      environments that have neither memmove() nor bcopy()) was defining its  
221      arguments as char * instead of void *.      (a) It was defining its arguments as char * instead of void *.
222    
223        (b) It was assuming that all moves were upwards in memory; this was true
224            a long time ago when I wrote it, but is no longer the case.
225    
226        The emulated memove() is provided for those environments that have neither
227        memmove() nor bcopy(). I didn't think anyone used it these days, but that
228        is clearly not the case, as these two bugs were recently reported.
229    
230  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,  11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
231      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
232      pages, and it removes trailing spaces from listed files. It also creates      pages, and it removes trailing spaces from listed files. It also creates
233      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
234      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
235      before "make dist".      before "make dist".
236    
237  12. Fixed two fairly obscure bugs concerned with quantified caseless matching  12. Fixed two fairly obscure bugs concerned with quantified caseless matching
238      with Unicode property support.      with Unicode property support.
239    
240      (a) For a maximizing quantifier, if the two different cases of the      (a) For a maximizing quantifier, if the two different cases of the
241          character were of different lengths in their UTF-8 codings (there are          character were of different lengths in their UTF-8 codings (there are
242          some cases like this - I found 11), and the matching function had to          some cases like this - I found 11), and the matching function had to
243          back up over a mixture of the two cases, it incorrectly assumed they          back up over a mixture of the two cases, it incorrectly assumed they
244          were both the same length.          were both the same length.
245    
246      (b) When PCRE was configured to use the heap rather than the stack for      (b) When PCRE was configured to use the heap rather than the stack for
247          recursion during matching, it was not correctly preserving the data for          recursion during matching, it was not correctly preserving the data for
248          the other case of a UTF-8 character when checking ahead for a match          the other case of a UTF-8 character when checking ahead for a match
249          while processing a minimizing repeat. If the check also involved          while processing a minimizing repeat. If the check also involved
250          matching a wide character, but failed, corruption could cause an          matching a wide character, but failed, corruption could cause an
251          erroneous result when trying to check for a repeat of the original          erroneous result when trying to check for a repeat of the original
252          character.          character.
253    
254    13. Some tidying changes to the testing mechanism:
255    
256        (a) The RunTest script now detects the internal link size and whether there
257            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
258            values substituted by "configure". (The RunGrepTest script already did
259            this for UTF-8.) The configure.ac script no longer substitutes the
260            relevant variables.
261    
262        (b) The debugging options /B and /D in pcretest show the compiled bytecode
263            with length and offset values. This means that the output is different
264            for different internal link sizes. Test 2 is skipped for link sizes
265            other than 2 because of this, bypassing the problem. Unfortunately,
266            there was also a test in test 3 (the locale tests) that used /B and
267            failed for link sizes other than 2. Rather than cut the whole test out,
268            I have added a new /Z option to pcretest that replaces the length and
269            offset values with spaces. This is now used to make test 3 independent
270            of link size. (Test 2 will be tidied up later.)
271    
272    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
273        segmentation fault instead of returning the appropriate error message.
274    
275    15. In multiline mode when the newline sequence was set to "any", the pattern
276        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
277        This doesn't seem right; it now treats the CRLF combination as the line
278        ending, and so does not match in that case. It's only a pattern such as ^$
279        that would hit this one: something like ^ABC$ would have failed after \r
280        and then tried again after \r\n.
281    
282    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
283        in an attempt to make files that differ only in their line terminators
284        compare equal. This works on Linux.
285    
286    17. Under certain error circumstances pcregrep might try to free random memory
287        as it exited. This is now fixed, thanks to valgrind.
288    
289    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
290        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
291        was because its rules for how to advance for /g after matching an empty
292        string at the end of a line did not allow for this case. They now check for
293        it specially.
294    
295    20. pcretest is supposed to handle patterns and data of any length, by
296        extending its buffers when necessary. It was getting this wrong when the
297        buffer for a data line had to be extended.
298    
299    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
300        CRLF as a newline sequence.
301    
302    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
303        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
304        I have nevertheless tidied it up.
305    
306    23. Added some casts to kill warnings from HP-UX ia64 compiler.
307    
308    24. Added a man page for pcre-config.
309    
310    
311  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
312  ---------------------  ---------------------

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