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

Diff of /code/trunk/ChangeLog

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

revision 399 by ph10, Sat Mar 21 12:34:15 2009 UTC revision 475 by ph10, Sat Jan 2 18:21:30 2010 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.9 xx-xxx-09  Version 8.01 11-Dec-09
5    ----------------------
6    
7    1.  If a pattern contained a conditional subpattern with only one branch (in
8        particular, this includes all (DEFINE) patterns), a call to pcre_study()
9        computed the wrong minimum data length (which is of course zero for such
10        subpatterns).
11    
12    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
13        the pattern is reset in the first branch, pcre_compile() failed with
14        "internal error: code overflow at offset...". This happened only when
15        the reset was to the original external option setting. (An optimization
16        abstracts leading options settings into an external setting, which was the
17        cause of this.)
18    
19    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
20        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
21        assertion pattern did not match (meaning that the assertion was true), it
22        was incorrectly treated as false if the SKIP had been reached during the
23        matching. This also applied to assertions used as conditions.
24    
25    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
26        assertion subpattern, including such a pattern used as a condition,
27        unpredictable results occurred, instead of the error return
28        PCRE_ERROR_DFA_UITEM.
29    
30    5.  The C++ GlobalReplace function was not working like Perl for the special
31        situation when an empty string is matched. It now does the fancy magic
32        stuff that is necessary.
33    
34    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
35        removed. (These were left over from very, very early versions of PCRE.)
36    
37    7.  Some cosmetic changes to the code to make life easier when compiling it
38        as part of something else:
39    
40        (a) Change DEBUG to PCRE_DEBUG.
41    
42        (b) In pcre_compile(), rename the member of the "branch_chain" structure
43            called "current" as "current_branch", to prevent a collision with the
44            Linux macro when compiled as a kernel module.
45    
46        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
47            prevent a collision with the Linux macro when compiled as a kernel
48            module.
49    
50    8.  In pcre_compile() there are some checks for integer overflows that used to
51        cast potentially large values to (double). This has been changed to that
52        when building, a check for int64_t is made, and if it is found, it is used
53        instead, thus avoiding the use of floating point arithmetic. (There is no
54        other use of FP in PCRE.) If int64_t is not found, the fallback is to
55        double.
56    
57    
58    
59    Version 8.00 19-Oct-09
60    ----------------------
61    
62    1.  The table for translating pcre_compile() error codes into POSIX error codes
63        was out-of-date, and there was no check on the pcre_compile() error code
64        being within the table. This could lead to an OK return being given in
65        error.
66    
67    2.  Changed the call to open a subject file in pcregrep from fopen(pathname,
68        "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
69        in a Windows environment.
70    
71    3.  The pcregrep --count option prints the count for each file even when it is
72        zero, as does GNU grep. However, pcregrep was also printing all files when
73        --files-with-matches was added. Now, when both options are given, it prints
74        counts only for those files that have at least one match. (GNU grep just
75        prints the file name in this circumstance, but including the count seems
76        more useful - otherwise, why use --count?) Also ensured that the
77        combination -clh just lists non-zero counts, with no names.
78    
79    4.  The long form of the pcregrep -F option was incorrectly implemented as
80        --fixed_strings instead of --fixed-strings. This is an incompatible change,
81        but it seems right to fix it, and I didn't think it was worth preserving
82        the old behaviour.
83    
84    5.  The command line items --regex=pattern and --regexp=pattern were not
85        recognized by pcregrep, which required --regex pattern or --regexp pattern
86        (with a space rather than an '='). The man page documented the '=' forms,
87        which are compatible with GNU grep; these now work.
88    
89    6.  No libpcreposix.pc file was created for pkg-config; there was just
90        libpcre.pc and libpcrecpp.pc. The omission has been rectified.
91    
92    7.  Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
93        when UCP support is not needed, by modifying the Python script that
94        generates it from Unicode data files. This should not matter if the module
95        is correctly used as a library, but I received one complaint about 50K of
96        unwanted data. My guess is that the person linked everything into his
97        program rather than using a library. Anyway, it does no harm.
98    
99    8.  A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
100        was a minimum greater than 1 for a wide character in a possessive
101        repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
102        which had an unlimited repeat of a nested, fixed maximum repeat of a wide
103        character. Chaos in the form of incorrect output or a compiling loop could
104        result.
105    
106    9.  The restrictions on what a pattern can contain when partial matching is
107        requested for pcre_exec() have been removed. All patterns can now be
108        partially matched by this function. In addition, if there are at least two
109        slots in the offset vector, the offset of the earliest inspected character
110        for the match and the offset of the end of the subject are set in them when
111        PCRE_ERROR_PARTIAL is returned.
112    
113    10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
114        synonymous with PCRE_PARTIAL, for backwards compatibility, and
115        PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
116        and may be more useful for multi-segment matching.
117    
118    11. Partial matching with pcre_exec() is now more intuitive. A partial match
119        used to be given if ever the end of the subject was reached; now it is
120        given only if matching could not proceed because another character was
121        needed. This makes a difference in some odd cases such as Z(*FAIL) with the
122        string "Z", which now yields "no match" instead of "partial match". In the
123        case of pcre_dfa_exec(), "no match" is given if every matching path for the
124        final character ended with (*FAIL).
125    
126    12. Restarting a match using pcre_dfa_exec() after a partial match did not work
127        if the pattern had a "must contain" character that was already found in the
128        earlier partial match, unless partial matching was again requested. For
129        example, with the pattern /dog.(body)?/, the "must contain" character is
130        "g". If the first part-match was for the string "dog", restarting with
131        "sbody" failed. This bug has been fixed.
132    
133    13. The string returned by pcre_dfa_exec() after a partial match has been
134        changed so that it starts at the first inspected character rather than the
135        first character of the match. This makes a difference only if the pattern
136        starts with a lookbehind assertion or \b or \B (\K is not supported by
137        pcre_dfa_exec()). It's an incompatible change, but it makes the two
138        matching functions compatible, and I think it's the right thing to do.
139    
140    14. Added a pcredemo man page, created automatically from the pcredemo.c file,
141        so that the demonstration program is easily available in environments where
142        PCRE has not been installed from source.
143    
144    15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
145        libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
146        library.
147    
148    16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
149        It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
150        is not the first non-POSIX option to be added. Clearly some people find
151        these options useful.
152    
153    17. If a caller to the POSIX matching function regexec() passes a non-zero
154        value for nmatch with a NULL value for pmatch, the value of
155        nmatch is forced to zero.
156    
157    18. RunGrepTest did not have a test for the availability of the -u option of
158        the diff command, as RunTest does. It now checks in the same way as
159        RunTest, and also checks for the -b option.
160    
161    19. If an odd number of negated classes containing just a single character
162        interposed, within parentheses, between a forward reference to a named
163        subpattern and the definition of the subpattern, compilation crashed with
164        an internal error, complaining that it could not find the referenced
165        subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
166        [The bug was that it was starting one character too far in when skipping
167        over the character class, thus treating the ] as data rather than
168        terminating the class. This meant it could skip too much.]
169    
170    20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
171        /g option in pcretest when the pattern contains \K, which makes it possible
172        to have an empty string match not at the start, even when the pattern is
173        anchored. Updated pcretest and pcredemo to use this option.
174    
175    21. If the maximum number of capturing subpatterns in a recursion was greater
176        than the maximum at the outer level, the higher number was returned, but
177        with unset values at the outer level. The correct (outer level) value is
178        now given.
179    
180    22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
181        PCRE did not set those parentheses (unlike Perl). I have now found a way to
182        make it do so. The string so far is captured, making this feature
183        compatible with Perl.
184    
185    23. The tests have been re-organized, adding tests 11 and 12, to make it
186        possible to check the Perl 5.10 features against Perl 5.10.
187    
188    24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
189        pattern matches a fixed length string. PCRE did not allow this; now it
190        does. Neither allows recursion.
191    
192    25. I finally figured out how to implement a request to provide the minimum
193        length of subject string that was needed in order to match a given pattern.
194        (It was back references and recursion that I had previously got hung up
195        on.) This code has now been added to pcre_study(); it finds a lower bound
196        to the length of subject needed. It is not necessarily the greatest lower
197        bound, but using it to avoid searching strings that are too short does give
198        some useful speed-ups. The value is available to calling programs via
199        pcre_fullinfo().
200    
201    26. While implementing 25, I discovered to my embarrassment that pcretest had
202        not been passing the result of pcre_study() to pcre_dfa_exec(), so the
203        study optimizations had never been tested with that matching function.
204        Oops. What is worse, even when it was passed study data, there was a bug in
205        pcre_dfa_exec() that meant it never actually used it. Double oops. There
206        were also very few tests of studied patterns with pcre_dfa_exec().
207    
208    27. If (?| is used to create subpatterns with duplicate numbers, they are now
209        allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
210        on the other side of the coin, they are no longer allowed to have different
211        names, because these cannot be distinguished in PCRE, and this has caused
212        confusion. (This is a difference from Perl.)
213    
214    28. When duplicate subpattern names are present (necessarily with different
215        numbers, as required by 27 above), and a test is made by name in a
216        conditional pattern, either for a subpattern having been matched, or for
217        recursion in such a pattern, all the associated numbered subpatterns are
218        tested, and the overall condition is true if the condition is true for any
219        one of them. This is the way Perl works, and is also more like the way
220        testing by number works.
221    
222    
223    Version 7.9 11-Apr-09
224  ---------------------  ---------------------
225    
226  1.  When building with support for bzlib/zlib (pcregrep) and/or readline  1.  When building with support for bzlib/zlib (pcregrep) and/or readline
# Line 17  Version 7.9 xx-xxx-09 Line 236  Version 7.9 xx-xxx-09
236      but BOOL is not.      but BOOL is not.
237    
238  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and  3.  The pcre_config() function was treating the PCRE_MATCH_LIMIT and
239      PCRE_MATCH_LIMIT_RETURSION values as ints, when they should be long ints.      PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
240    
241  4.  The pcregrep documentation said spaces were inserted as well as colons (or  4.  The pcregrep documentation said spaces were inserted as well as colons (or
242      hyphens) following file names and line numbers when outputting matching      hyphens) following file names and line numbers when outputting matching
# Line 42  Version 7.9 xx-xxx-09 Line 261  Version 7.9 xx-xxx-09
261      correctly handled. The rule now is that both the assertion and what follows      correctly handled. The rule now is that both the assertion and what follows
262      in the first alternative must satisfy the test.      in the first alternative must satisfy the test.
263    
264  9.  If auto-callout was enabled in a pattern with a conditional group whose  9.  If auto-callout was enabled in a pattern with a conditional group whose
265      condition was an assertion, PCRE could crash during matching, both with      condition was an assertion, PCRE could crash during matching, both with
266      pcre_exec() and pcre_dfa_exec().      pcre_exec() and pcre_dfa_exec().
267    
# Line 64  Version 7.9 xx-xxx-09 Line 283  Version 7.9 xx-xxx-09
283  17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch  17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
284      from Martin Jerabek that uses macro names for all relevant character and      from Martin Jerabek that uses macro names for all relevant character and
285      string constants.      string constants.
286    
287  18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and  18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
288      SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without      SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
289      SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of      SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
290      these, but not everybody uses configure.      these, but not everybody uses configure.
291    
292  19. A conditional group that had only one branch was not being correctly  19. A conditional group that had only one branch was not being correctly
293      recognized as an item that could match an empty string. This meant that an      recognized as an item that could match an empty string. This meant that an
294      enclosing group might also not be so recognized, causing infinite looping      enclosing group might also not be so recognized, causing infinite looping
295      (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$      (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
296      with the subject "ab", where knowledge that the repeated group can match      with the subject "ab", where knowledge that the repeated group can match
297      nothing is needed in order to break the loop.      nothing is needed in order to break the loop.
298    
299  20. If a pattern that was compiled with callouts was matched using pcre_dfa_  20. If a pattern that was compiled with callouts was matched using pcre_dfa_
300      exec(), but without supplying a callout function, matching went wrong.      exec(), but without supplying a callout function, matching went wrong.
301    
302    21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
303        leak if the size of the offset vector was greater than 30. When the vector
304        is smaller, the saved offsets during recursion go onto a local stack
305        vector, but for larger vectors malloc() is used. It was failing to free
306        when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
307        error, in fact).
308    
309    22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
310        heapframe that is used only when UTF-8 support is enabled. This caused no
311        problem, but was untidy.
312    
313    23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
314        CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
315        included within another project.
316    
317    24. Steven Van Ingelgem's patches to add more options to the CMake support,
318        slightly modified by me:
319    
320          (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
321              not building pcregrep.
322    
323          (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
324              if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
325    
326    25. Forward references, both numeric and by name, in patterns that made use of
327        duplicate group numbers, could behave incorrectly or give incorrect errors,
328        because when scanning forward to find the reference group, PCRE was not
329        taking into account the duplicate group numbers. A pattern such as
330        ^X(?3)(a)(?|(b)|(q))(Y) is an example.
331    
332    26. Changed a few more instances of "const unsigned char *" to USPTR, making
333        the feature of a custom pointer more persuasive (as requested by a user).
334    
335    27. Wrapped the definitions of fileno and isatty for Windows, which appear in
336        pcretest.c, inside #ifndefs, because it seems they are sometimes already
337        pre-defined.
338    
339    28. Added support for (*UTF8) at the start of a pattern.
340    
341    29. Arrange for flags added by the "release type" setting in CMake to be shown
342        in the configuration summary.
343    
344    
345  Version 7.8 05-Sep-08  Version 7.8 05-Sep-08

Legend:
Removed from v.399  
changed lines
  Added in v.475

  ViewVC Help
Powered by ViewVC 1.1.5