ViewVC logotype

Diff of /code/trunk/ChangeLog

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

revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC revision 175 by ph10, Mon Jun 11 13:38:38 2007 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 7.2 05-June-07
5    ---------------------
7     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
8        which is apparently normally available under Windows.
10     2. Re-jig the pcregrep tests with different newline settings in an attempt
11        to make them independent of the local environment's newline setting.
13     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
15     4. Some of the "internals" tests were previously cut out when the link size
16        was not 2, because the output contained actual offsets. The recent new
17        "Z" feature of pcretest means that these can be cut out, making the tests
18        usable with all link sizes.
20     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
21        stack recursion. This gives a massive performance boost under BSD, but just
22        a small improvement under Linux. However, it saves one field in the frame
23        in all cases.
25     6. Added more features from the forthcoming Perl 5.10:
27        (a) (?-n) (where n is a string of digits) is a relative subroutine or
28            recursion call. It refers to the nth most recently opened parentheses.
30        (b) (?+n) is also a relative subroutine call; it refers to the nth next
31            to be opened parentheses.
33        (c) Conditions that refer to capturing parentheses can be specified
34            relatively, for example, (?(-2)... or (?(+3)...
36        (d) \K resets the start of the current match so that everything before
37            is not part of it.
39        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
41        (f) \g{name} is another synonym - part of Perl 5.10's unification of
42            reference syntax.
44        (g) (?| introduces a group in which the numbering of parentheses in each
45            alternative starts with the same number.
47     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
50     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
51        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
52        for detecting groups that can match an empty string.
54     9. A pattern with a very large number of alternatives (more than several
55        hundred) was running out of internal workspace during the pre-compile
56        phase, where pcre_compile() figures out how much memory will be needed. A
57        bit of new cunning has reduced the workspace needed for groups with
58        alternatives. The 1000-alternative test pattern now uses 12 bytes of
59        workspace instead of running out of the 4096 that are available.
62    Version 7.1 24-Apr-07
63    ---------------------
65     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
66        that is more "standard", making use of automake and other Autotools. There
67        is some re-arrangement of the files and adjustment of comments consequent
68        on this.
70     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
71        for recursive directory scanning broke on some systems because the files
72        are not scanned in any specific order and on different systems the order
73        was different. A call to "sort" has been inserted into RunGrepTest for the
74        approprate test as a short-term fix. In the longer term there may be an
75        alternative.
77     3. I had an email from Eric Raymond about problems translating some of PCRE's
78        man pages to HTML (despite the fact that I distribute HTML pages, some
79        people do their own conversions for various reasons). The problems
80        concerned the use of low-level troff macros .br and .in. I have therefore
81        removed all such uses from the man pages (some were redundant, some could
82        be replaced by .nf/.fi pairs). The 132html script that I use to generate
83        HTML has been updated to handle .nf/.fi and to complain if it encounters
84        .br or .in.
86     4. Updated comments in configure.ac that get placed in config.h.in and also
87        arranged for config.h to be included in the distribution, with the name
88        config.h.generic, for the benefit of those who have to compile without
89        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
91     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
92        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
93        makevp.bat for the current PCRE, using the additional files
94        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
96     6. A Windows user reported a minor discrepancy with test 2, which turned out
97        to be caused by a trailing space on an input line that had got lost in his
98        copy. The trailing space was an accident, so I've just removed it.
100     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
101        that is needed.
103     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
104        as "const" (a) because they are and (b) because it helps the PHP
105        maintainers who have recently made a script to detect big data structures
106        in the php code that should be moved to the .rodata section. I remembered
107        to update Builducptable as well, so it won't revert if ucptable.h is ever
108        re-created.
110     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
111        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
112        order to be able to cut out the UTF-8 tables in the latter when UTF-8
113        support is not required. This saves 1.5-2K of code, which is important in
114        some applications.
116        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
117        so as not to refer to the tables, even though these functions will never be
118        called when UTF-8 support is disabled. Otherwise there are problems with a
119        shared library.
121    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
123        (a) It was defining its arguments as char * instead of void *.
125        (b) It was assuming that all moves were upwards in memory; this was true
126            a long time ago when I wrote it, but is no longer the case.
128        The emulated memove() is provided for those environments that have neither
129        memmove() nor bcopy(). I didn't think anyone used it these days, but that
130        is clearly not the case, as these two bugs were recently reported.
132    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
133        and Detrail to create the HTML documentation, the .txt form of the man
134        pages, and it removes trailing spaces from listed files. It also creates
135        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
136        case, it wraps all the #defines with #ifndefs. This script should be run
137        before "make dist".
139    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
140        with Unicode property support.
142        (a) For a maximizing quantifier, if the two different cases of the
143            character were of different lengths in their UTF-8 codings (there are
144            some cases like this - I found 11), and the matching function had to
145            back up over a mixture of the two cases, it incorrectly assumed they
146            were both the same length.
148        (b) When PCRE was configured to use the heap rather than the stack for
149            recursion during matching, it was not correctly preserving the data for
150            the other case of a UTF-8 character when checking ahead for a match
151            while processing a minimizing repeat. If the check also involved
152            matching a wide character, but failed, corruption could cause an
153            erroneous result when trying to check for a repeat of the original
154            character.
156    13. Some tidying changes to the testing mechanism:
158        (a) The RunTest script now detects the internal link size and whether there
159            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
160            values substituted by "configure". (The RunGrepTest script already did
161            this for UTF-8.) The configure.ac script no longer substitutes the
162            relevant variables.
164        (b) The debugging options /B and /D in pcretest show the compiled bytecode
165            with length and offset values. This means that the output is different
166            for different internal link sizes. Test 2 is skipped for link sizes
167            other than 2 because of this, bypassing the problem. Unfortunately,
168            there was also a test in test 3 (the locale tests) that used /B and
169            failed for link sizes other than 2. Rather than cut the whole test out,
170            I have added a new /Z option to pcretest that replaces the length and
171            offset values with spaces. This is now used to make test 3 independent
172            of link size. (Test 2 will be tidied up later.)
174    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
175        segmentation fault instead of returning the appropriate error message.
177    15. In multiline mode when the newline sequence was set to "any", the pattern
178        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
179        This doesn't seem right; it now treats the CRLF combination as the line
180        ending, and so does not match in that case. It's only a pattern such as ^$
181        that would hit this one: something like ^ABC$ would have failed after \r
182        and then tried again after \r\n.
184    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
185        in an attempt to make files that differ only in their line terminators
186        compare equal. This works on Linux.
188    17. Under certain error circumstances pcregrep might try to free random memory
189        as it exited. This is now fixed, thanks to valgrind.
191    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
192        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
193        was because its rules for how to advance for /g after matching an empty
194        string at the end of a line did not allow for this case. They now check for
195        it specially.
197    20. pcretest is supposed to handle patterns and data of any length, by
198        extending its buffers when necessary. It was getting this wrong when the
199        buffer for a data line had to be extended.
201    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
202        CRLF as a newline sequence.
204    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
205        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
206        I have nevertheless tidied it up.
208    23. Added some casts to kill warnings from HP-UX ia64 compiler.
210    24. Added a man page for pcre-config.
213    Version 7.0 19-Dec-06
214    ---------------------
216     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
217        moving to gcc 4.1.1.
219     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
220        sys/time.h, which is documented as needed for this function. It doesn't
221        seem to matter on Linux, but it showed up on some releases of OS X.
223     3. It seems that there are systems where bytes whose values are greater than
224        127 match isprint() in the "C" locale. The "C" locale should be the
225        default when a C program starts up. In most systems, only ASCII printing
226        characters match isprint(). This difference caused the output from pcretest
227        to vary, making some of the tests fail. I have changed pcretest so that:
229        (a) When it is outputting text in the compiled version of a pattern, bytes
230            other than 32-126 are always shown as hex escapes.
232        (b) When it is outputting text that is a matched part of a subject string,
233            it does the same, unless a different locale has been set for the match
234            (using the /L modifier). In this case, it uses isprint() to decide.
236     4. Fixed a major bug that caused incorrect computation of the amount of memory
237        required for a compiled pattern when options that changed within the
238        pattern affected the logic of the preliminary scan that determines the
239        length. The relevant options are -x, and -i in UTF-8 mode. The result was
240        that the computed length was too small. The symptoms of this bug were
241        either the PCRE error "internal error: code overflow" from pcre_compile(),
242        or a glibc crash with a message such as "pcretest: free(): invalid next
243        size (fast)". Examples of patterns that provoked this bug (shown in
244        pcretest format) are:
246          /(?-x: )/x
247          /(?x)(?-x: \s*#\s*)/
248          /((?i)[\x{c0}])/8
249          /(?i:[\x{c0}])/8
251        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
252        is now done differently.
254     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
255        wrapper classes; (b) implement a new function in the C++ scanner that is
256        more efficient than the old way of doing things because it avoids levels of
257        recursion in the regex matching; (c) add a paragraph to the documentation
258        for the FullMatch() function.
260     6. The escape sequence \n was being treated as whatever was defined as
261        "newline". Not only was this contrary to the documentation, which states
262        that \n is character 10 (hex 0A), but it also went horribly wrong when
263        "newline" was defined as CRLF. This has been fixed.
265     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
266        was being set to -1 for the "end of line" case (supposedly a value that no
267        character can have). Though this value is never used (the check for end of
268        line is "zero bytes in current character"), it caused compiler complaints.
269        I've changed it to 0xffffffff.
271     8. In pcre_version.c, the version string was being built by a sequence of
272        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
273        string (as it is for production releases) called a macro with an empty
274        argument. The C standard says the result of this is undefined. The gcc
275        compiler treats it as an empty string (which was what was wanted) but it is
276        reported that Visual C gives an error. The source has been hacked around to
277        avoid this problem.
279     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
280        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
281        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
282        of them did).
284    10. Originally, pcretest opened its input and output without "b"; then I was
285        told that "b" was needed in some environments, so it was added for release
286        5.0 to both the input and output. (It makes no difference on Unix-like
287        systems.) Later I was told that it is wrong for the input on Windows. I've
288        now abstracted the modes into two macros, to make it easier to fiddle with
289        them, and removed "b" from the input mode under Windows.
291    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
293    12. Added -help and --help to pcretest as an official way of being reminded
294        of the options.
296    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
297        and pcrecpp.cc because they annoy compilers at high warning levels.
299    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
301    15. Fixed an occurrence of == in configure.ac that should have been = (shell
302        scripts are not C programs :-) and which was not noticed because it works
303        on Linux.
305    16. pcretest is supposed to handle any length of pattern and data line (as one
306        line or as a continued sequence of lines) by extending its input buffer if
307        necessary. This feature was broken for very long pattern lines, leading to
308        a string of junk being passed to pcre_compile() if the pattern was longer
309        than about 50K.
311    17. I have done a major re-factoring of the way pcre_compile() computes the
312        amount of memory needed for a compiled pattern. Previously, there was code
313        that made a preliminary scan of the pattern in order to do this. That was
314        OK when PCRE was new, but as the facilities have expanded, it has become
315        harder and harder to keep it in step with the real compile phase, and there
316        have been a number of bugs (see for example, 4 above). I have now found a
317        cunning way of running the real compile function in a "fake" mode that
318        enables it to compute how much memory it would need, while actually only
319        ever using a few hundred bytes of working memory and without too many
320        tests of the mode. This should make future maintenance and development
321        easier. A side effect of this work is that the limit of 200 on the nesting
322        depth of parentheses has been removed (though this was never a serious
323        limitation, I suspect). However, there is a downside: pcre_compile() now
324        runs more slowly than before (30% or more, depending on the pattern). I
325        hope this isn't a big issue. There is no effect on runtime performance.
327    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
328        newline (only possible for the last line of a file) and it was a
329        pattern that set a locale (followed by /Lsomething), pcretest crashed.
331    19. Added additional timing features to pcretest. (1) The -tm option now times
332        matching only, not compiling. (2) Both -t and -tm can be followed, as a
333        separate command line item, by a number that specifies the number of
334        repeats to use when timing. The default is 50000; this gives better
335        precision, but takes uncomfortably long for very large patterns.
337    20. Extended pcre_study() to be more clever in cases where a branch of a
338        subpattern has no definite first character. For example, (a*|b*)[cd] would
339        previously give no result from pcre_study(). Now it recognizes that the
340        first character must be a, b, c, or d.
342    21. There was an incorrect error "recursive call could loop indefinitely" if
343        a subpattern (or the entire pattern) that was being tested for matching an
344        empty string contained only one non-empty item after a nested subpattern.
345        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
346        incorrectly, because the \d was being skipped in the check.
348    22. The pcretest program now has a new pattern option /B and a command line
349        option -b, which is equivalent to adding /B to every pattern. This causes
350        it to show the compiled bytecode, without the additional information that
351        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
352        is the same as /B/I).
354    23. A new optimization is now able automatically to treat some sequences such
355        as a*b as a*+b. More specifically, if something simple (such as a character
356        or a simple class like \d) has an unlimited quantifier, and is followed by
357        something that cannot possibly match the quantified thing, the quantifier
358        is automatically "possessified".
360    24. A recursive reference to a subpattern whose number was greater than 39
361        went wrong under certain circumstances in UTF-8 mode. This bug could also
362        have affected the operation of pcre_study().
364    25. Realized that a little bit of performance could be had by replacing
365        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
367    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
369    27. Possessive quantifiers such as a++ were previously implemented by turning
370        them into atomic groups such as ($>a+). Now they have their own opcodes,
371        which improves performance. This includes the automatically created ones
372        from 23 above.
374    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
375        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
376        the first matched character to be a colon. This applied both to named and
377        numbered groups.
379    29. The ucpinternal.h header file was missing its idempotency #ifdef.
381    30. I was sent a "project" file called libpcre.a.dev which I understand makes
382        building PCRE on Windows easier, so I have included it in the distribution.
384    31. There is now a check in pcretest against a ridiculously large number being
385        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
386        loop, the loop is abandoned.
388    32. Forward references to subpatterns in conditions such as (?(2)...) where
389        subpattern 2 is defined later cause pcre_compile() to search forwards in
390        the pattern for the relevant set of parentheses. This search went wrong
391        when there were unescaped parentheses in a character class, parentheses
392        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
394    33. "Subroutine" calls and backreferences were previously restricted to
395        referencing subpatterns earlier in the regex. This restriction has now
396        been removed.
398    34. Added a number of extra features that are going to be in Perl 5.10. On the
399        whole, these are just syntactic alternatives for features that PCRE had
400        previously implemented using the Python syntax or my own invention. The
401        other formats are all retained for compatibility.
403        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
404            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
405            also .NET compatible.
407        (b) A recursion or subroutine call to a named group can now be defined as
408            (?&name) as well as (?P>name).
410        (c) A backreference to a named group can now be defined as \k<name> or
411            \k'name' as well as (?P=name). The new forms, as well as being in Perl
412            5.10, are also .NET compatible.
414        (d) A conditional reference to a named group can now use the syntax
415            (?(<name>) or (?('name') as well as (?(name).
417        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
418            groups (named and numbered) that are never evaluated inline, but can be
419            called as "subroutines" from elsewhere. In effect, the DEFINE condition
420            is always false. There may be only one alternative in such a group.
422        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
423            as the simple (?(R). The condition is true only if the most recent
424            recursion is that of the given number or name. It does not search out
425            through the entire recursion stack.
427        (g) The escape \gN or \g{N} has been added, where N is a positive or
428            negative number, specifying an absolute or relative reference.
430    35. Tidied to get rid of some further signed/unsigned compiler warnings and
431        some "unreachable code" warnings.
433    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
434        things, this adds five new scripts.
436    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
437        There were also incompatibilities regarding the handling of \Q..\E inside
438        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
439        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
441    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
442        matches an empty string, and forcibly breaks the loop. There were bugs in
443        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
444        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
445        separate and independent bugs (that affected different cases) have been
446        fixed.
448    39. Refactored the code to abolish the use of different opcodes for small
449        capturing bracket numbers. This is a tidy that I avoided doing when I
450        removed the limit on the number of capturing brackets for 3.5 back in 2001.
451        The new approach is not only tidier, it makes it possible to reduce the
452        memory needed to fix the previous bug (38).
454    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
455        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
456        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
457        mode.
459    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
460        report.
462    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
463        copy construction and assignment in the C++ wrapper.
465    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
466        couple of bugs that could have given wrong results in the "--newline=crlf"
467        case.
469    44. Added a number of casts and did some reorganization of signed/unsigned int
470        variables following suggestions from Dair Grant. Also renamed the variable
471        "this" as "item" because it is a C++ keyword.
473    45. Arranged for dftables to add
475          #include "pcre_internal.h"
477        to pcre_chartables.c because without it, gcc 4.x may remove the array
478        definition from the final binary if PCRE is built into a static library and
479        dead code stripping is activated.
481    46. For an unanchored pattern, if a match attempt fails at the start of a
482        newline sequence, and the newline setting is CRLF or ANY, and the next two
483        characters are CRLF, advance by two characters instead of one.
486  Version 6.7 04-Jul-06  Version 6.7 04-Jul-06
487  ---------------------  ---------------------

Removed from v.91  
changed lines
  Added in v.175

  ViewVC Help
Powered by ViewVC 1.1.5