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revision 100 by ph10, Tue Mar 6 14:53:10 2007 UTC revision 202 by ph10, Fri Aug 3 09:44:26 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. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. In the rejigging of the build system that eventually resulted in 7.1, the
8      that is more "standard", making use of automake and other autotools. There      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    
69    Version 7.2 19-Jun-07
70    ---------------------
71    
72     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
73        which is apparently normally available under Windows.
74    
75     2. Re-jig the pcregrep tests with different newline settings in an attempt
76        to make them independent of the local environment's newline setting.
77    
78     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
79    
80     4. Some of the "internals" tests were previously cut out when the link size
81        was not 2, because the output contained actual offsets. The recent new
82        "Z" feature of pcretest means that these can be cut out, making the tests
83        usable with all link sizes.
84    
85     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
86        stack recursion. This gives a massive performance boost under BSD, but just
87        a small improvement under Linux. However, it saves one field in the frame
88        in all cases.
89    
90     6. Added more features from the forthcoming Perl 5.10:
91    
92        (a) (?-n) (where n is a string of digits) is a relative subroutine or
93            recursion call. It refers to the nth most recently opened parentheses.
94    
95        (b) (?+n) is also a relative subroutine call; it refers to the nth next
96            to be opened parentheses.
97    
98        (c) Conditions that refer to capturing parentheses can be specified
99            relatively, for example, (?(-2)... or (?(+3)...
100    
101        (d) \K resets the start of the current match so that everything before
102            is not part of it.
103    
104        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
105    
106        (f) \g{name} is another synonym - part of Perl 5.10's unification of
107            reference syntax.
108    
109        (g) (?| introduces a group in which the numbering of parentheses in each
110            alternative starts with the same number.
111    
112        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
113    
114     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
115        PCRE_INFO_JCHANGED.
116    
117     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
118        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
119        for detecting groups that can match an empty string.
120    
121     9. A pattern with a very large number of alternatives (more than several
122        hundred) was running out of internal workspace during the pre-compile
123        phase, where pcre_compile() figures out how much memory will be needed. A
124        bit of new cunning has reduced the workspace needed for groups with
125        alternatives. The 1000-alternative test pattern now uses 12 bytes of
126        workspace instead of running out of the 4096 that are available.
127    
128    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
129    
130    11. Applied patch from Google to remove an optimization that didn't quite work.
131        The report of the bug said:
132    
133          pcrecpp::RE("a*").FullMatch("aaa") matches, while
134          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
135          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
136    
137    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
138        it matched the wrong number of bytes.
139    
140    
141    Version 7.1 24-Apr-07
142    ---------------------
143    
144     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
145        that is more "standard", making use of automake and other Autotools. There
146      is some re-arrangement of the files and adjustment of comments consequent      is some re-arrangement of the files and adjustment of comments consequent
147      on this.      on this.
148    
149   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r   2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
150      for recursive directory scanning broke on some systems because the files      for recursive directory scanning broke on some systems because the files
151      are not scanned in any specific order and on different systems the order      are not scanned in any specific order and on different systems the order
152      was different. A call to "sort" has been inserted into RunGrepTest for the      was different. A call to "sort" has been inserted into RunGrepTest for the
153      approprate test as a short-term fix. In the longer term there may be an      approprate test as a short-term fix. In the longer term there may be an
154      alternative.      alternative.
155    
156   3. I had an email from Eric Raymond about problems translating some of PCRE's   3. I had an email from Eric Raymond about problems translating some of PCRE's
157      man pages to HTML (despite the fact that I distribute HTML pages, some      man pages to HTML (despite the fact that I distribute HTML pages, some
158      people do their own conversions for various reasons). The problems      people do their own conversions for various reasons). The problems
159      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
160      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
161      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
162      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
163      encounters .br or .in.      .br or .in.
164    
165   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
166      arranged for config.h to be included in the distribution, for the benefit      arranged for config.h to be included in the distribution, with the name
167      of those who have to compile without Autotools (compare pcre.h).      config.h.generic, for the benefit of those who have to compile without
168        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
169    
170     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
171        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
172        makevp.bat for the current PCRE, using the additional files
173        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
174    
175     6. A Windows user reported a minor discrepancy with test 2, which turned out
176        to be caused by a trailing space on an input line that had got lost in his
177        copy. The trailing space was an accident, so I've just removed it.
178    
179     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
180        that is needed.
181    
182     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
183        as "const" (a) because they are and (b) because it helps the PHP
184        maintainers who have recently made a script to detect big data structures
185        in the php code that should be moved to the .rodata section. I remembered
186        to update Builducptable as well, so it won't revert if ucptable.h is ever
187        re-created.
188    
189     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
190        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
191        order to be able to cut out the UTF-8 tables in the latter when UTF-8
192        support is not required. This saves 1.5-2K of code, which is important in
193        some applications.
194    
195        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
196        so as not to refer to the tables, even though these functions will never be
197        called when UTF-8 support is disabled. Otherwise there are problems with a
198        shared library.
199    
200    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
201    
202        (a) It was defining its arguments as char * instead of void *.
203    
204        (b) It was assuming that all moves were upwards in memory; this was true
205            a long time ago when I wrote it, but is no longer the case.
206    
207        The emulated memove() is provided for those environments that have neither
208        memmove() nor bcopy(). I didn't think anyone used it these days, but that
209        is clearly not the case, as these two bugs were recently reported.
210    
211    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
212        and Detrail to create the HTML documentation, the .txt form of the man
213        pages, and it removes trailing spaces from listed files. It also creates
214        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
215        case, it wraps all the #defines with #ifndefs. This script should be run
216        before "make dist".
217    
218    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
219        with Unicode property support.
220    
221        (a) For a maximizing quantifier, if the two different cases of the
222            character were of different lengths in their UTF-8 codings (there are
223            some cases like this - I found 11), and the matching function had to
224            back up over a mixture of the two cases, it incorrectly assumed they
225            were both the same length.
226    
227        (b) When PCRE was configured to use the heap rather than the stack for
228            recursion during matching, it was not correctly preserving the data for
229            the other case of a UTF-8 character when checking ahead for a match
230            while processing a minimizing repeat. If the check also involved
231            matching a wide character, but failed, corruption could cause an
232            erroneous result when trying to check for a repeat of the original
233            character.
234    
235    13. Some tidying changes to the testing mechanism:
236    
237        (a) The RunTest script now detects the internal link size and whether there
238            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
239            values substituted by "configure". (The RunGrepTest script already did
240            this for UTF-8.) The configure.ac script no longer substitutes the
241            relevant variables.
242    
243        (b) The debugging options /B and /D in pcretest show the compiled bytecode
244            with length and offset values. This means that the output is different
245            for different internal link sizes. Test 2 is skipped for link sizes
246            other than 2 because of this, bypassing the problem. Unfortunately,
247            there was also a test in test 3 (the locale tests) that used /B and
248            failed for link sizes other than 2. Rather than cut the whole test out,
249            I have added a new /Z option to pcretest that replaces the length and
250            offset values with spaces. This is now used to make test 3 independent
251            of link size. (Test 2 will be tidied up later.)
252    
253    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
254        segmentation fault instead of returning the appropriate error message.
255    
256    15. In multiline mode when the newline sequence was set to "any", the pattern
257        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
258        This doesn't seem right; it now treats the CRLF combination as the line
259        ending, and so does not match in that case. It's only a pattern such as ^$
260        that would hit this one: something like ^ABC$ would have failed after \r
261        and then tried again after \r\n.
262    
263    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
264        in an attempt to make files that differ only in their line terminators
265        compare equal. This works on Linux.
266    
267    17. Under certain error circumstances pcregrep might try to free random memory
268        as it exited. This is now fixed, thanks to valgrind.
269    
270    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
271        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
272        was because its rules for how to advance for /g after matching an empty
273        string at the end of a line did not allow for this case. They now check for
274        it specially.
275    
276    20. pcretest is supposed to handle patterns and data of any length, by
277        extending its buffers when necessary. It was getting this wrong when the
278        buffer for a data line had to be extended.
279    
280    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
281        CRLF as a newline sequence.
282    
283    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
284        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
285        I have nevertheless tidied it up.
286    
287    23. Added some casts to kill warnings from HP-UX ia64 compiler.
288    
289    24. Added a man page for pcre-config.
290    
291    
292  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
293  ---------------------  ---------------------

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