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revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC revision 332 by ph10, Sat Apr 5 16:11:05 2008 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 7.7 05-Mar-08
5    ---------------------
6    
7    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
8        a string to a long long, pretend we don't even have a long long." This is
9        done by checking for the strtoq, strtoll, and _strtoi64 functions.
10    
11    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
12        pre-7.6 versions, which defined a global no_arg variable instead of putting
13        it in the RE class. (See also #8 below.)
14    
15    3.  Remove a line of dead code, identified by coverity and reported by Nuno
16        Lopes.
17    
18    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
19    
20        (1) The include/exclude patterns were being applied to the whole pathnames
21            of files, instead of just to the final components.
22    
23        (2) If there was more than one level of directory, the subdirectories were
24            skipped unless they satisfied the include/exclude conditions. This is
25            inconsistent with GNU grep (and could even be seen as contrary to the
26            pcregrep specification - which I improved to make it absolutely clear).
27            The action now is always to scan all levels of directory, and just
28            apply the include/exclude patterns to regular files.
29    
30    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
31        --exclude_dir in the tests to avoid scanning .svn directories.
32    
33    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
34        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
35        doesn't support NULs in patterns.
36    
37    7.  Added some missing "const"s to declarations of static tables in
38        pcre_compile.c and pcre_dfa_exec.c.
39    
40    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
41        caused by fix #2  above. (Subsequently also a second patch to fix the
42        first patch. And a third patch - this was a messy problem.)
43    
44    9.  Applied Craig's patch to remove the use of push_back().
45    
46    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
47        matching function regexec().
48    
49    
50    Version 7.6 28-Jan-08
51    ---------------------
52    
53    1.  A character class containing a very large number of characters with
54        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
55        overflow.
56    
57    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
58        HAVE_LONG_LONG is not defined.
59    
60    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
61        bring them up to date and include new features. This patch includes:
62    
63        - Fixed PH's badly added libz and libbz2 support.
64        - Fixed a problem with static linking.
65        - Added pcredemo. [But later removed - see 7 below.]
66        - Fixed dftables problem and added an option.
67        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
68            HAVE_LONG_LONG.
69        - Added readline support for pcretest.
70        - Added an listing of the option settings after cmake has run.
71    
72    4.  A user submitted a patch to Makefile that makes it easy to create
73        "pcre.dll" under mingw when using Configure/Make. I added stuff to
74        Makefile.am that cause it to include this special target, without
75        affecting anything else. Note that the same mingw target plus all
76        the other distribution libraries and programs are now supported
77        when configuring with CMake (see 6 below) instead of with
78        Configure/Make.
79    
80    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
81        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
82        exported in the Windows port". It has not yet been confirmed that the patch
83        solves the problem, but it does no harm.
84    
85    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
86        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
87        with CMake, and also correct the comment about stack recursion.
88    
89    7.  Remove the automatic building of pcredemo from the ./configure system and
90        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
91        of a program that users should build themselves after PCRE is installed, so
92        building it automatically is not really right. What is more, it gave
93        trouble in some build environments.
94    
95    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
96    
97    
98    Version 7.5 10-Jan-08
99    ---------------------
100    
101    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
102        values in parens when parsing an RE using the C++ wrapper."
103    
104    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
105        Characters greater than 255 were excluded from the class instead of being
106        included.
107    
108    3.  The same bug as (2) above applied to negated POSIX classes such as
109        [:^space:].
110    
111    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
112        defined or documented. It seems to have been a typo for PCRE_STATIC, so
113        I have changed it.
114    
115    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
116        first named subpattern) and a construct such as (?&a) would reference the
117        first named subpattern whose name started with "a" (in other words, the
118        length check was missing). Both these problems are fixed. "Subpattern name
119        expected" is now given for (?&) (a zero-length name), and this patch also
120        makes it give the same error for \k'' (previously it complained that that
121        was a reference to a non-existent subpattern).
122    
123    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
124        this is right because (?- can be followed by option settings as well as by
125        digits. I have, however, made the messages clearer.
126    
127    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
128        than the number used in the conditional) now cause a compile-time error.
129        This is actually not compatible with Perl, which accepts such patterns, but
130        treats the conditional as always being FALSE (as PCRE used to), but it
131        seems to me that giving a diagnostic is better.
132    
133    8.  Change "alphameric" to the more common word "alphanumeric" in comments
134        and messages.
135    
136    9.  Fix two occurrences of "backslash" in comments that should have been
137        "backspace".
138    
139    10. Remove two redundant lines of code that can never be obeyed (their function
140        was moved elsewhere).
141    
142    11. The program that makes PCRE's Unicode character property table had a bug
143        which caused it to generate incorrect table entries for sequences of
144        characters that have the same character type, but are in different scripts.
145        It amalgamated them into a single range, with the script of the first of
146        them. In other words, some characters were in the wrong script. There were
147        thirteen such cases, affecting characters in the following ranges:
148    
149          U+002b0 - U+002c1
150          U+0060c - U+0060d
151          U+0061e - U+00612
152          U+0064b - U+0065e
153          U+0074d - U+0076d
154          U+01800 - U+01805
155          U+01d00 - U+01d77
156          U+01d9b - U+01dbf
157          U+0200b - U+0200f
158          U+030fc - U+030fe
159          U+03260 - U+0327f
160          U+0fb46 - U+0fbb1
161          U+10450 - U+1049d
162    
163    12. The -o option (show only the matching part of a line) for pcregrep was not
164        compatible with GNU grep in that, if there was more than one match in a
165        line, it showed only the first of them. It now behaves in the same way as
166        GNU grep.
167    
168    13. If the -o and -v options were combined for pcregrep, it printed a blank
169        line for every non-matching line. GNU grep prints nothing, and pcregrep now
170        does the same. The return code can be used to tell if there were any
171        non-matching lines.
172    
173    14. Added --file-offsets and --line-offsets to pcregrep.
174    
175    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
176        infinitely looping recursion. The bug was that positive lookaheads were not
177        being skipped when checking for a possible empty match (negative lookaheads
178        and both kinds of lookbehind were skipped).
179    
180    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
181        inclusion of <windows.h> to before rather than after the definition of
182        INVALID_FILE_ATTRIBUTES (patch from David Byron).
183    
184    17. Specifying a possessive quantifier with a specific limit for a Unicode
185        character property caused pcre_compile() to compile bad code, which led at
186        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
187        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
188        caused the error; without that there was no problem.
189    
190    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
191    
192    19. Added --enable-pcretest-libreadline.
193    
194    20. In pcrecpp.cc, the variable 'count' was incremented twice in
195        RE::GlobalReplace(). As a result, the number of replacements returned was
196        double what it should be. I removed one of the increments, but Craig sent a
197        later patch that removed the other one (the right fix) and added unit tests
198        that check the return values (which was not done before).
199    
200    21. Several CMake things:
201    
202        (1) Arranged that, when cmake is used on Unix, the libraries end up with
203            the names libpcre and libpcreposix, not just pcre and pcreposix.
204    
205        (2) The above change means that pcretest and pcregrep are now correctly
206            linked with the newly-built libraries, not previously installed ones.
207    
208        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
209    
210    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
211        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
212        UTF-8 newline character). The key issue is that the pattern starts .*;
213        this means that the match must be either at the beginning, or after a
214        newline. The bug was in the code for advancing after a failed match and
215        checking that the new position followed a newline. It was not taking
216        account of UTF-8 characters correctly.
217    
218    23. PCRE was behaving differently from Perl in the way it recognized POSIX
219        character classes. PCRE was not treating the sequence [:...:] as a
220        character class unless the ... were all letters. Perl, however, seems to
221        allow any characters between [: and :], though of course it rejects as
222        unknown any "names" that contain non-letters, because all the known class
223        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
224        for example, whereas PCRE did not - it did not recognize a POSIX character
225        class. This seemed a bit dangerous, so the code has been changed to be
226        closer to Perl. The behaviour is not identical to Perl, because PCRE will
227        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
228        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
229        Perl does, and where it didn't before.
230    
231    24. Rewrite so as to remove the single use of %n from pcregrep because in some
232        Windows environments %n is disabled by default.
233    
234    
235    Version 7.4 21-Sep-07
236    ---------------------
237    
238    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
239        means that a class such as [\s] counted as "explicit reference to CR or
240        LF". That isn't really right - the whole point of the change was to try to
241        help when there was an actual mention of one of the two characters. So now
242        the change happens only if \r or \n (or a literal CR or LF) character is
243        encountered.
244    
245    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
246        of both had grown to the point where there were only 3 bits left.
247        Fortunately, there was spare space in the data structure, and so I have
248        moved the internal flags into a new 16-bit field to free up more option
249        bits.
250    
251    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
252        but did not set the internal JCHANGED flag - either of these is enough to
253        control the way the "get" function works - but the PCRE_INFO_JCHANGED
254        facility is supposed to tell if (?J) was ever used, so now (?J) at the
255        start sets both bits.
256    
257    4.  Added options (at build time, compile time, exec time) to change \R from
258        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
259    
260    5.  doc/pcresyntax.html was missing from the distribution.
261    
262    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
263        compatibility, even though it is no longer used.
264    
265    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
266        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
267        windows.h file is present (where different names are used). [This was
268        reversed later after testing - see 16 below.]
269    
270    8.  Changed all #include <config.h> to #include "config.h". There were also
271        some further <pcre.h> cases that I changed to "pcre.h".
272    
273    9.  When pcregrep was used with the --colour option, it missed the line ending
274        sequence off the lines that it output.
275    
276    10. It was pointed out to me that arrays of string pointers cause lots of
277        relocations when a shared library is dynamically loaded. A technique of
278        using a single long string with a table of offsets can drastically reduce
279        these. I have refactored PCRE in four places to do this. The result is
280        dramatic:
281    
282          Originally:                          290
283          After changing UCP table:            187
284          After changing error message table:   43
285          After changing table of "verbs"       36
286          After changing table of Posix names   22
287    
288        Thanks to the folks working on Gregex for glib for this insight.
289    
290    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
291        unicode-properties was also set.
292    
293    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
294    
295    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
296        checked only for CRLF.
297    
298    14. Added casts to pcretest.c to avoid compiler warnings.
299    
300    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
301    
302    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
303        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
304        entirely. This removes changes made in 7 above.
305    
306    17. The CMake files have been updated, and there is now more information about
307        building with CMake in the NON-UNIX-USE document.
308    
309    
310    Version 7.3 28-Aug-07
311    ---------------------
312    
313     1. In the rejigging of the build system that eventually resulted in 7.1, the
314        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
315        brackets there is not right, since it causes compilers to look for an
316        installed pcre.h, not the version that is in the source that is being
317        compiled (which of course may be different). I have changed it back to:
318    
319          #include "pcre.h"
320    
321        I have a vague recollection that the change was concerned with compiling in
322        different directories, but in the new build system, that is taken care of
323        by the VPATH setting the Makefile.
324    
325     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
326        when the subject happened to end in the byte 0x85 (e.g. if the last
327        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
328        characters but of course it shouldn't be taken as a newline when it is part
329        of another character. The bug was that, for an unlimited repeat of . in
330        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
331        characters when looking for a newline.
332    
333     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
334    
335     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
336        in debug output.
337    
338     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
339        long printing in the pcrecpp unittest when running under MinGW.
340    
341     6. ESC_K was left out of the EBCDIC table.
342    
343     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
344        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
345        limit also applies to "virtual nesting" when a pattern is recursive, and in
346        this case 1000 isn't so big. I have been able to remove this limit at the
347        expense of backing off one optimization in certain circumstances. Normally,
348        when pcre_exec() would call its internal match() function recursively and
349        immediately return the result unconditionally, it uses a "tail recursion"
350        feature to save stack. However, when a subpattern that can match an empty
351        string has an unlimited repetition quantifier, it no longer makes this
352        optimization. That gives it a stack frame in which to save the data for
353        checking that an empty string has been matched. Previously this was taken
354        from the 1000-entry workspace that had been reserved. So now there is no
355        explicit limit, but more stack is used.
356    
357     8. Applied Daniel's patches to solve problems with the import/export magic
358        syntax that is required for Windows, and which was going wrong for the
359        pcreposix and pcrecpp parts of the library. These were overlooked when this
360        problem was solved for the main library.
361    
362     9. There were some crude static tests to avoid integer overflow when computing
363        the size of patterns that contain repeated groups with explicit upper
364        limits. As the maximum quantifier is 65535, the maximum group length was
365        set at 30,000 so that the product of these two numbers did not overflow a
366        32-bit integer. However, it turns out that people want to use groups that
367        are longer than 30,000 bytes (though not repeat them that many times).
368        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
369        made it possible to implement the integer overflow checks in a much more
370        dynamic way, which I have now done. The artificial limitation on group
371        length has been removed - we now have only the limit on the total length of
372        the compiled pattern, which depends on the LINK_SIZE setting.
373    
374    10. Fixed a bug in the documentation for get/copy named substring when
375        duplicate names are permitted. If none of the named substrings are set, the
376        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
377        empty string.
378    
379    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
380        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
381        because the ] is interpreted as the first data character and the
382        terminating ] is not found. PCRE has been made compatible with Perl in this
383        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
384        cause memory overwriting.
385    
386    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
387        string has been matched (to stop an infinite loop). It was not recognizing
388        a conditional subpattern that could match an empty string if that
389        subpattern was within another subpattern. For example, it looped when
390        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
391        condition was not nested. This bug has been fixed.
392    
393    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
394        past the start of the subject in the presence of bytes with the top bit
395        set, for example "\x8aBCD".
396    
397    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
398        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
399    
400    14. Optimized (?!) to (*FAIL).
401    
402    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
403        This restricts code points to be within the range 0 to 0x10FFFF, excluding
404        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
405        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
406        does: it's just the validity check that is more restrictive.
407    
408    16. Inserted checks for integer overflows during escape sequence (backslash)
409        processing, and also fixed erroneous offset values for syntax errors during
410        backslash processing.
411    
412    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
413        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
414    
415    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
416        caused an overrun.
417    
418    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
419        something other than just ASCII characters) inside a group that had an
420        unlimited repeat caused a loop at compile time (while checking to see
421        whether the group could match an empty string).
422    
423    20. Debugging a pattern containing \p or \P could cause a crash. For example,
424        [\P{Any}] did so. (Error in the code for printing property names.)
425    
426    21. An orphan \E inside a character class could cause a crash.
427    
428    22. A repeated capturing bracket such as (A)? could cause a wild memory
429        reference during compilation.
430    
431    23. There are several functions in pcre_compile() that scan along a compiled
432        expression for various reasons (e.g. to see if it's fixed length for look
433        behind). There were bugs in these functions when a repeated \p or \P was
434        present in the pattern. These operators have additional parameters compared
435        with \d, etc, and these were not being taken into account when moving along
436        the compiled data. Specifically:
437    
438        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
439            length.
440    
441        (b) An item such as \pL+ within a repeated group could cause crashes or
442            loops.
443    
444        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
445            "reference to non-existent subpattern" error.
446    
447        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
448    
449    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
450        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
451    
452    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
453    
454    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
455        character were causing crashes (broken optimization).
456    
457    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
458        \p or \P) caused a compile-time loop.
459    
460    28. More problems have arisen in unanchored patterns when CRLF is a valid line
461        break. For example, the unstudied pattern [\r\n]A does not match the string
462        "\r\nA" because change 7.0/46 below moves the current point on by two
463        characters after failing to match at the start. However, the pattern \nA
464        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
465        the same is true. There doesn't seem any very clean way out of this, but
466        what I have chosen to do makes the common cases work: PCRE now takes note
467        of whether there can be an explicit match for \r or \n anywhere in the
468        pattern, and if so, 7.0/46 no longer applies. As part of this change,
469        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
470        pattern has explicit CR or LF references.
471    
472    29. Added (*CR) etc for changing newline setting at start of pattern.
473    
474    
475    Version 7.2 19-Jun-07
476    ---------------------
477    
478     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
479        which is apparently normally available under Windows.
480    
481     2. Re-jig the pcregrep tests with different newline settings in an attempt
482        to make them independent of the local environment's newline setting.
483    
484     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
485    
486     4. Some of the "internals" tests were previously cut out when the link size
487        was not 2, because the output contained actual offsets. The recent new
488        "Z" feature of pcretest means that these can be cut out, making the tests
489        usable with all link sizes.
490    
491     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
492        stack recursion. This gives a massive performance boost under BSD, but just
493        a small improvement under Linux. However, it saves one field in the frame
494        in all cases.
495    
496     6. Added more features from the forthcoming Perl 5.10:
497    
498        (a) (?-n) (where n is a string of digits) is a relative subroutine or
499            recursion call. It refers to the nth most recently opened parentheses.
500    
501        (b) (?+n) is also a relative subroutine call; it refers to the nth next
502            to be opened parentheses.
503    
504        (c) Conditions that refer to capturing parentheses can be specified
505            relatively, for example, (?(-2)... or (?(+3)...
506    
507        (d) \K resets the start of the current match so that everything before
508            is not part of it.
509    
510        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
511    
512        (f) \g{name} is another synonym - part of Perl 5.10's unification of
513            reference syntax.
514    
515        (g) (?| introduces a group in which the numbering of parentheses in each
516            alternative starts with the same number.
517    
518        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
519    
520     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
521        PCRE_INFO_JCHANGED.
522    
523     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
524        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
525        for detecting groups that can match an empty string.
526    
527     9. A pattern with a very large number of alternatives (more than several
528        hundred) was running out of internal workspace during the pre-compile
529        phase, where pcre_compile() figures out how much memory will be needed. A
530        bit of new cunning has reduced the workspace needed for groups with
531        alternatives. The 1000-alternative test pattern now uses 12 bytes of
532        workspace instead of running out of the 4096 that are available.
533    
534    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
535    
536    11. Applied patch from Google to remove an optimization that didn't quite work.
537        The report of the bug said:
538    
539          pcrecpp::RE("a*").FullMatch("aaa") matches, while
540          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
541          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
542    
543    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
544        it matched the wrong number of bytes.
545    
546    
547    Version 7.1 24-Apr-07
548    ---------------------
549    
550     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
551        that is more "standard", making use of automake and other Autotools. There
552        is some re-arrangement of the files and adjustment of comments consequent
553        on this.
554    
555     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
556        for recursive directory scanning broke on some systems because the files
557        are not scanned in any specific order and on different systems the order
558        was different. A call to "sort" has been inserted into RunGrepTest for the
559        approprate test as a short-term fix. In the longer term there may be an
560        alternative.
561    
562     3. I had an email from Eric Raymond about problems translating some of PCRE's
563        man pages to HTML (despite the fact that I distribute HTML pages, some
564        people do their own conversions for various reasons). The problems
565        concerned the use of low-level troff macros .br and .in. I have therefore
566        removed all such uses from the man pages (some were redundant, some could
567        be replaced by .nf/.fi pairs). The 132html script that I use to generate
568        HTML has been updated to handle .nf/.fi and to complain if it encounters
569        .br or .in.
570    
571     4. Updated comments in configure.ac that get placed in config.h.in and also
572        arranged for config.h to be included in the distribution, with the name
573        config.h.generic, for the benefit of those who have to compile without
574        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
575    
576     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
577        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
578        makevp.bat for the current PCRE, using the additional files
579        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
580    
581     6. A Windows user reported a minor discrepancy with test 2, which turned out
582        to be caused by a trailing space on an input line that had got lost in his
583        copy. The trailing space was an accident, so I've just removed it.
584    
585     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
586        that is needed.
587    
588     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
589        as "const" (a) because they are and (b) because it helps the PHP
590        maintainers who have recently made a script to detect big data structures
591        in the php code that should be moved to the .rodata section. I remembered
592        to update Builducptable as well, so it won't revert if ucptable.h is ever
593        re-created.
594    
595     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
596        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
597        order to be able to cut out the UTF-8 tables in the latter when UTF-8
598        support is not required. This saves 1.5-2K of code, which is important in
599        some applications.
600    
601        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
602        so as not to refer to the tables, even though these functions will never be
603        called when UTF-8 support is disabled. Otherwise there are problems with a
604        shared library.
605    
606    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
607    
608        (a) It was defining its arguments as char * instead of void *.
609    
610        (b) It was assuming that all moves were upwards in memory; this was true
611            a long time ago when I wrote it, but is no longer the case.
612    
613        The emulated memove() is provided for those environments that have neither
614        memmove() nor bcopy(). I didn't think anyone used it these days, but that
615        is clearly not the case, as these two bugs were recently reported.
616    
617    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
618        and Detrail to create the HTML documentation, the .txt form of the man
619        pages, and it removes trailing spaces from listed files. It also creates
620        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
621        case, it wraps all the #defines with #ifndefs. This script should be run
622        before "make dist".
623    
624    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
625        with Unicode property support.
626    
627        (a) For a maximizing quantifier, if the two different cases of the
628            character were of different lengths in their UTF-8 codings (there are
629            some cases like this - I found 11), and the matching function had to
630            back up over a mixture of the two cases, it incorrectly assumed they
631            were both the same length.
632    
633        (b) When PCRE was configured to use the heap rather than the stack for
634            recursion during matching, it was not correctly preserving the data for
635            the other case of a UTF-8 character when checking ahead for a match
636            while processing a minimizing repeat. If the check also involved
637            matching a wide character, but failed, corruption could cause an
638            erroneous result when trying to check for a repeat of the original
639            character.
640    
641    13. Some tidying changes to the testing mechanism:
642    
643        (a) The RunTest script now detects the internal link size and whether there
644            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
645            values substituted by "configure". (The RunGrepTest script already did
646            this for UTF-8.) The configure.ac script no longer substitutes the
647            relevant variables.
648    
649        (b) The debugging options /B and /D in pcretest show the compiled bytecode
650            with length and offset values. This means that the output is different
651            for different internal link sizes. Test 2 is skipped for link sizes
652            other than 2 because of this, bypassing the problem. Unfortunately,
653            there was also a test in test 3 (the locale tests) that used /B and
654            failed for link sizes other than 2. Rather than cut the whole test out,
655            I have added a new /Z option to pcretest that replaces the length and
656            offset values with spaces. This is now used to make test 3 independent
657            of link size. (Test 2 will be tidied up later.)
658    
659    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
660        segmentation fault instead of returning the appropriate error message.
661    
662    15. In multiline mode when the newline sequence was set to "any", the pattern
663        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
664        This doesn't seem right; it now treats the CRLF combination as the line
665        ending, and so does not match in that case. It's only a pattern such as ^$
666        that would hit this one: something like ^ABC$ would have failed after \r
667        and then tried again after \r\n.
668    
669    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
670        in an attempt to make files that differ only in their line terminators
671        compare equal. This works on Linux.
672    
673    17. Under certain error circumstances pcregrep might try to free random memory
674        as it exited. This is now fixed, thanks to valgrind.
675    
676    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
677        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
678        was because its rules for how to advance for /g after matching an empty
679        string at the end of a line did not allow for this case. They now check for
680        it specially.
681    
682    20. pcretest is supposed to handle patterns and data of any length, by
683        extending its buffers when necessary. It was getting this wrong when the
684        buffer for a data line had to be extended.
685    
686    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
687        CRLF as a newline sequence.
688    
689    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
690        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
691        I have nevertheless tidied it up.
692    
693    23. Added some casts to kill warnings from HP-UX ia64 compiler.
694    
695    24. Added a man page for pcre-config.
696    
697    
698    Version 7.0 19-Dec-06
699    ---------------------
700    
701     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
702        moving to gcc 4.1.1.
703    
704     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
705        sys/time.h, which is documented as needed for this function. It doesn't
706        seem to matter on Linux, but it showed up on some releases of OS X.
707    
708     3. It seems that there are systems where bytes whose values are greater than
709        127 match isprint() in the "C" locale. The "C" locale should be the
710        default when a C program starts up. In most systems, only ASCII printing
711        characters match isprint(). This difference caused the output from pcretest
712        to vary, making some of the tests fail. I have changed pcretest so that:
713    
714        (a) When it is outputting text in the compiled version of a pattern, bytes
715            other than 32-126 are always shown as hex escapes.
716    
717        (b) When it is outputting text that is a matched part of a subject string,
718            it does the same, unless a different locale has been set for the match
719            (using the /L modifier). In this case, it uses isprint() to decide.
720    
721     4. Fixed a major bug that caused incorrect computation of the amount of memory
722        required for a compiled pattern when options that changed within the
723        pattern affected the logic of the preliminary scan that determines the
724        length. The relevant options are -x, and -i in UTF-8 mode. The result was
725        that the computed length was too small. The symptoms of this bug were
726        either the PCRE error "internal error: code overflow" from pcre_compile(),
727        or a glibc crash with a message such as "pcretest: free(): invalid next
728        size (fast)". Examples of patterns that provoked this bug (shown in
729        pcretest format) are:
730    
731          /(?-x: )/x
732          /(?x)(?-x: \s*#\s*)/
733          /((?i)[\x{c0}])/8
734          /(?i:[\x{c0}])/8
735    
736        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
737        is now done differently.
738    
739     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
740        wrapper classes; (b) implement a new function in the C++ scanner that is
741        more efficient than the old way of doing things because it avoids levels of
742        recursion in the regex matching; (c) add a paragraph to the documentation
743        for the FullMatch() function.
744    
745     6. The escape sequence \n was being treated as whatever was defined as
746        "newline". Not only was this contrary to the documentation, which states
747        that \n is character 10 (hex 0A), but it also went horribly wrong when
748        "newline" was defined as CRLF. This has been fixed.
749    
750     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
751        was being set to -1 for the "end of line" case (supposedly a value that no
752        character can have). Though this value is never used (the check for end of
753        line is "zero bytes in current character"), it caused compiler complaints.
754        I've changed it to 0xffffffff.
755    
756     8. In pcre_version.c, the version string was being built by a sequence of
757        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
758        string (as it is for production releases) called a macro with an empty
759        argument. The C standard says the result of this is undefined. The gcc
760        compiler treats it as an empty string (which was what was wanted) but it is
761        reported that Visual C gives an error. The source has been hacked around to
762        avoid this problem.
763    
764     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
765        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
766        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
767        of them did).
768    
769    10. Originally, pcretest opened its input and output without "b"; then I was
770        told that "b" was needed in some environments, so it was added for release
771        5.0 to both the input and output. (It makes no difference on Unix-like
772        systems.) Later I was told that it is wrong for the input on Windows. I've
773        now abstracted the modes into two macros, to make it easier to fiddle with
774        them, and removed "b" from the input mode under Windows.
775    
776    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
777    
778    12. Added -help and --help to pcretest as an official way of being reminded
779        of the options.
780    
781    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
782        and pcrecpp.cc because they annoy compilers at high warning levels.
783    
784    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
785    
786    15. Fixed an occurrence of == in configure.ac that should have been = (shell
787        scripts are not C programs :-) and which was not noticed because it works
788        on Linux.
789    
790    16. pcretest is supposed to handle any length of pattern and data line (as one
791        line or as a continued sequence of lines) by extending its input buffer if
792        necessary. This feature was broken for very long pattern lines, leading to
793        a string of junk being passed to pcre_compile() if the pattern was longer
794        than about 50K.
795    
796    17. I have done a major re-factoring of the way pcre_compile() computes the
797        amount of memory needed for a compiled pattern. Previously, there was code
798        that made a preliminary scan of the pattern in order to do this. That was
799        OK when PCRE was new, but as the facilities have expanded, it has become
800        harder and harder to keep it in step with the real compile phase, and there
801        have been a number of bugs (see for example, 4 above). I have now found a
802        cunning way of running the real compile function in a "fake" mode that
803        enables it to compute how much memory it would need, while actually only
804        ever using a few hundred bytes of working memory and without too many
805        tests of the mode. This should make future maintenance and development
806        easier. A side effect of this work is that the limit of 200 on the nesting
807        depth of parentheses has been removed (though this was never a serious
808        limitation, I suspect). However, there is a downside: pcre_compile() now
809        runs more slowly than before (30% or more, depending on the pattern). I
810        hope this isn't a big issue. There is no effect on runtime performance.
811    
812    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
813        newline (only possible for the last line of a file) and it was a
814        pattern that set a locale (followed by /Lsomething), pcretest crashed.
815    
816    19. Added additional timing features to pcretest. (1) The -tm option now times
817        matching only, not compiling. (2) Both -t and -tm can be followed, as a
818        separate command line item, by a number that specifies the number of
819        repeats to use when timing. The default is 50000; this gives better
820        precision, but takes uncomfortably long for very large patterns.
821    
822    20. Extended pcre_study() to be more clever in cases where a branch of a
823        subpattern has no definite first character. For example, (a*|b*)[cd] would
824        previously give no result from pcre_study(). Now it recognizes that the
825        first character must be a, b, c, or d.
826    
827    21. There was an incorrect error "recursive call could loop indefinitely" if
828        a subpattern (or the entire pattern) that was being tested for matching an
829        empty string contained only one non-empty item after a nested subpattern.
830        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
831        incorrectly, because the \d was being skipped in the check.
832    
833    22. The pcretest program now has a new pattern option /B and a command line
834        option -b, which is equivalent to adding /B to every pattern. This causes
835        it to show the compiled bytecode, without the additional information that
836        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
837        is the same as /B/I).
838    
839    23. A new optimization is now able automatically to treat some sequences such
840        as a*b as a*+b. More specifically, if something simple (such as a character
841        or a simple class like \d) has an unlimited quantifier, and is followed by
842        something that cannot possibly match the quantified thing, the quantifier
843        is automatically "possessified".
844    
845    24. A recursive reference to a subpattern whose number was greater than 39
846        went wrong under certain circumstances in UTF-8 mode. This bug could also
847        have affected the operation of pcre_study().
848    
849    25. Realized that a little bit of performance could be had by replacing
850        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
851    
852    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
853    
854    27. Possessive quantifiers such as a++ were previously implemented by turning
855        them into atomic groups such as ($>a+). Now they have their own opcodes,
856        which improves performance. This includes the automatically created ones
857        from 23 above.
858    
859    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
860        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
861        the first matched character to be a colon. This applied both to named and
862        numbered groups.
863    
864    29. The ucpinternal.h header file was missing its idempotency #ifdef.
865    
866    30. I was sent a "project" file called libpcre.a.dev which I understand makes
867        building PCRE on Windows easier, so I have included it in the distribution.
868    
869    31. There is now a check in pcretest against a ridiculously large number being
870        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
871        loop, the loop is abandoned.
872    
873    32. Forward references to subpatterns in conditions such as (?(2)...) where
874        subpattern 2 is defined later cause pcre_compile() to search forwards in
875        the pattern for the relevant set of parentheses. This search went wrong
876        when there were unescaped parentheses in a character class, parentheses
877        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
878    
879    33. "Subroutine" calls and backreferences were previously restricted to
880        referencing subpatterns earlier in the regex. This restriction has now
881        been removed.
882    
883    34. Added a number of extra features that are going to be in Perl 5.10. On the
884        whole, these are just syntactic alternatives for features that PCRE had
885        previously implemented using the Python syntax or my own invention. The
886        other formats are all retained for compatibility.
887    
888        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
889            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
890            also .NET compatible.
891    
892        (b) A recursion or subroutine call to a named group can now be defined as
893            (?&name) as well as (?P>name).
894    
895        (c) A backreference to a named group can now be defined as \k<name> or
896            \k'name' as well as (?P=name). The new forms, as well as being in Perl
897            5.10, are also .NET compatible.
898    
899        (d) A conditional reference to a named group can now use the syntax
900            (?(<name>) or (?('name') as well as (?(name).
901    
902        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
903            groups (named and numbered) that are never evaluated inline, but can be
904            called as "subroutines" from elsewhere. In effect, the DEFINE condition
905            is always false. There may be only one alternative in such a group.
906    
907        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
908            as the simple (?(R). The condition is true only if the most recent
909            recursion is that of the given number or name. It does not search out
910            through the entire recursion stack.
911    
912        (g) The escape \gN or \g{N} has been added, where N is a positive or
913            negative number, specifying an absolute or relative reference.
914    
915    35. Tidied to get rid of some further signed/unsigned compiler warnings and
916        some "unreachable code" warnings.
917    
918    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
919        things, this adds five new scripts.
920    
921    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
922        There were also incompatibilities regarding the handling of \Q..\E inside
923        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
924        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
925    
926    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
927        matches an empty string, and forcibly breaks the loop. There were bugs in
928        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
929        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
930        separate and independent bugs (that affected different cases) have been
931        fixed.
932    
933    39. Refactored the code to abolish the use of different opcodes for small
934        capturing bracket numbers. This is a tidy that I avoided doing when I
935        removed the limit on the number of capturing brackets for 3.5 back in 2001.
936        The new approach is not only tidier, it makes it possible to reduce the
937        memory needed to fix the previous bug (38).
938    
939    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
940        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
941        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
942        mode.
943    
944    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
945        report.
946    
947    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
948        copy construction and assignment in the C++ wrapper.
949    
950    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
951        couple of bugs that could have given wrong results in the "--newline=crlf"
952        case.
953    
954    44. Added a number of casts and did some reorganization of signed/unsigned int
955        variables following suggestions from Dair Grant. Also renamed the variable
956        "this" as "item" because it is a C++ keyword.
957    
958    45. Arranged for dftables to add
959    
960          #include "pcre_internal.h"
961    
962        to pcre_chartables.c because without it, gcc 4.x may remove the array
963        definition from the final binary if PCRE is built into a static library and
964        dead code stripping is activated.
965    
966    46. For an unanchored pattern, if a match attempt fails at the start of a
967        newline sequence, and the newline setting is CRLF or ANY, and the next two
968        characters are CRLF, advance by two characters instead of one.
969    
970    
971  Version 6.7 04-Jul-06  Version 6.7 04-Jul-06
972  ---------------------  ---------------------
973    

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