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revision 69 by nigel, Sat Feb 24 21:40:18 2007 UTC revision 331 by ph10, Sat Apr 5 15:38:53 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.
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    
47    Version 7.6 28-Jan-08
48    ---------------------
49    
50    1.  A character class containing a very large number of characters with
51        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
52        overflow.
53    
54    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
55        HAVE_LONG_LONG is not defined.
56    
57    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
58        bring them up to date and include new features. This patch includes:
59    
60        - Fixed PH's badly added libz and libbz2 support.
61        - Fixed a problem with static linking.
62        - Added pcredemo. [But later removed - see 7 below.]
63        - Fixed dftables problem and added an option.
64        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
65            HAVE_LONG_LONG.
66        - Added readline support for pcretest.
67        - Added an listing of the option settings after cmake has run.
68    
69    4.  A user submitted a patch to Makefile that makes it easy to create
70        "pcre.dll" under mingw when using Configure/Make. I added stuff to
71        Makefile.am that cause it to include this special target, without
72        affecting anything else. Note that the same mingw target plus all
73        the other distribution libraries and programs are now supported
74        when configuring with CMake (see 6 below) instead of with
75        Configure/Make.
76    
77    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
78        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
79        exported in the Windows port". It has not yet been confirmed that the patch
80        solves the problem, but it does no harm.
81    
82    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
83        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
84        with CMake, and also correct the comment about stack recursion.
85    
86    7.  Remove the automatic building of pcredemo from the ./configure system and
87        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
88        of a program that users should build themselves after PCRE is installed, so
89        building it automatically is not really right. What is more, it gave
90        trouble in some build environments.
91    
92    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
93    
94    
95    Version 7.5 10-Jan-08
96    ---------------------
97    
98    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
99        values in parens when parsing an RE using the C++ wrapper."
100    
101    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
102        Characters greater than 255 were excluded from the class instead of being
103        included.
104    
105    3.  The same bug as (2) above applied to negated POSIX classes such as
106        [:^space:].
107    
108    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
109        defined or documented. It seems to have been a typo for PCRE_STATIC, so
110        I have changed it.
111    
112    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
113        first named subpattern) and a construct such as (?&a) would reference the
114        first named subpattern whose name started with "a" (in other words, the
115        length check was missing). Both these problems are fixed. "Subpattern name
116        expected" is now given for (?&) (a zero-length name), and this patch also
117        makes it give the same error for \k'' (previously it complained that that
118        was a reference to a non-existent subpattern).
119    
120    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
121        this is right because (?- can be followed by option settings as well as by
122        digits. I have, however, made the messages clearer.
123    
124    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
125        than the number used in the conditional) now cause a compile-time error.
126        This is actually not compatible with Perl, which accepts such patterns, but
127        treats the conditional as always being FALSE (as PCRE used to), but it
128        seems to me that giving a diagnostic is better.
129    
130    8.  Change "alphameric" to the more common word "alphanumeric" in comments
131        and messages.
132    
133    9.  Fix two occurrences of "backslash" in comments that should have been
134        "backspace".
135    
136    10. Remove two redundant lines of code that can never be obeyed (their function
137        was moved elsewhere).
138    
139    11. The program that makes PCRE's Unicode character property table had a bug
140        which caused it to generate incorrect table entries for sequences of
141        characters that have the same character type, but are in different scripts.
142        It amalgamated them into a single range, with the script of the first of
143        them. In other words, some characters were in the wrong script. There were
144        thirteen such cases, affecting characters in the following ranges:
145    
146          U+002b0 - U+002c1
147          U+0060c - U+0060d
148          U+0061e - U+00612
149          U+0064b - U+0065e
150          U+0074d - U+0076d
151          U+01800 - U+01805
152          U+01d00 - U+01d77
153          U+01d9b - U+01dbf
154          U+0200b - U+0200f
155          U+030fc - U+030fe
156          U+03260 - U+0327f
157          U+0fb46 - U+0fbb1
158          U+10450 - U+1049d
159    
160    12. The -o option (show only the matching part of a line) for pcregrep was not
161        compatible with GNU grep in that, if there was more than one match in a
162        line, it showed only the first of them. It now behaves in the same way as
163        GNU grep.
164    
165    13. If the -o and -v options were combined for pcregrep, it printed a blank
166        line for every non-matching line. GNU grep prints nothing, and pcregrep now
167        does the same. The return code can be used to tell if there were any
168        non-matching lines.
169    
170    14. Added --file-offsets and --line-offsets to pcregrep.
171    
172    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
173        infinitely looping recursion. The bug was that positive lookaheads were not
174        being skipped when checking for a possible empty match (negative lookaheads
175        and both kinds of lookbehind were skipped).
176    
177    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
178        inclusion of <windows.h> to before rather than after the definition of
179        INVALID_FILE_ATTRIBUTES (patch from David Byron).
180    
181    17. Specifying a possessive quantifier with a specific limit for a Unicode
182        character property caused pcre_compile() to compile bad code, which led at
183        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
184        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
185        caused the error; without that there was no problem.
186    
187    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
188    
189    19. Added --enable-pcretest-libreadline.
190    
191    20. In pcrecpp.cc, the variable 'count' was incremented twice in
192        RE::GlobalReplace(). As a result, the number of replacements returned was
193        double what it should be. I removed one of the increments, but Craig sent a
194        later patch that removed the other one (the right fix) and added unit tests
195        that check the return values (which was not done before).
196    
197    21. Several CMake things:
198    
199        (1) Arranged that, when cmake is used on Unix, the libraries end up with
200            the names libpcre and libpcreposix, not just pcre and pcreposix.
201    
202        (2) The above change means that pcretest and pcregrep are now correctly
203            linked with the newly-built libraries, not previously installed ones.
204    
205        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
206    
207    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
208        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
209        UTF-8 newline character). The key issue is that the pattern starts .*;
210        this means that the match must be either at the beginning, or after a
211        newline. The bug was in the code for advancing after a failed match and
212        checking that the new position followed a newline. It was not taking
213        account of UTF-8 characters correctly.
214    
215    23. PCRE was behaving differently from Perl in the way it recognized POSIX
216        character classes. PCRE was not treating the sequence [:...:] as a
217        character class unless the ... were all letters. Perl, however, seems to
218        allow any characters between [: and :], though of course it rejects as
219        unknown any "names" that contain non-letters, because all the known class
220        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
221        for example, whereas PCRE did not - it did not recognize a POSIX character
222        class. This seemed a bit dangerous, so the code has been changed to be
223        closer to Perl. The behaviour is not identical to Perl, because PCRE will
224        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
225        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
226        Perl does, and where it didn't before.
227    
228    24. Rewrite so as to remove the single use of %n from pcregrep because in some
229        Windows environments %n is disabled by default.
230    
231    
232    Version 7.4 21-Sep-07
233    ---------------------
234    
235    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
236        means that a class such as [\s] counted as "explicit reference to CR or
237        LF". That isn't really right - the whole point of the change was to try to
238        help when there was an actual mention of one of the two characters. So now
239        the change happens only if \r or \n (or a literal CR or LF) character is
240        encountered.
241    
242    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
243        of both had grown to the point where there were only 3 bits left.
244        Fortunately, there was spare space in the data structure, and so I have
245        moved the internal flags into a new 16-bit field to free up more option
246        bits.
247    
248    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
249        but did not set the internal JCHANGED flag - either of these is enough to
250        control the way the "get" function works - but the PCRE_INFO_JCHANGED
251        facility is supposed to tell if (?J) was ever used, so now (?J) at the
252        start sets both bits.
253    
254    4.  Added options (at build time, compile time, exec time) to change \R from
255        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
256    
257    5.  doc/pcresyntax.html was missing from the distribution.
258    
259    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
260        compatibility, even though it is no longer used.
261    
262    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
263        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
264        windows.h file is present (where different names are used). [This was
265        reversed later after testing - see 16 below.]
266    
267    8.  Changed all #include <config.h> to #include "config.h". There were also
268        some further <pcre.h> cases that I changed to "pcre.h".
269    
270    9.  When pcregrep was used with the --colour option, it missed the line ending
271        sequence off the lines that it output.
272    
273    10. It was pointed out to me that arrays of string pointers cause lots of
274        relocations when a shared library is dynamically loaded. A technique of
275        using a single long string with a table of offsets can drastically reduce
276        these. I have refactored PCRE in four places to do this. The result is
277        dramatic:
278    
279          Originally:                          290
280          After changing UCP table:            187
281          After changing error message table:   43
282          After changing table of "verbs"       36
283          After changing table of Posix names   22
284    
285        Thanks to the folks working on Gregex for glib for this insight.
286    
287    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
288        unicode-properties was also set.
289    
290    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
291    
292    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
293        checked only for CRLF.
294    
295    14. Added casts to pcretest.c to avoid compiler warnings.
296    
297    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
298    
299    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
300        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
301        entirely. This removes changes made in 7 above.
302    
303    17. The CMake files have been updated, and there is now more information about
304        building with CMake in the NON-UNIX-USE document.
305    
306    
307    Version 7.3 28-Aug-07
308    ---------------------
309    
310     1. In the rejigging of the build system that eventually resulted in 7.1, the
311        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
312        brackets there is not right, since it causes compilers to look for an
313        installed pcre.h, not the version that is in the source that is being
314        compiled (which of course may be different). I have changed it back to:
315    
316          #include "pcre.h"
317    
318        I have a vague recollection that the change was concerned with compiling in
319        different directories, but in the new build system, that is taken care of
320        by the VPATH setting the Makefile.
321    
322     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
323        when the subject happened to end in the byte 0x85 (e.g. if the last
324        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
325        characters but of course it shouldn't be taken as a newline when it is part
326        of another character. The bug was that, for an unlimited repeat of . in
327        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
328        characters when looking for a newline.
329    
330     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
331    
332     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
333        in debug output.
334    
335     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
336        long printing in the pcrecpp unittest when running under MinGW.
337    
338     6. ESC_K was left out of the EBCDIC table.
339    
340     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
341        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
342        limit also applies to "virtual nesting" when a pattern is recursive, and in
343        this case 1000 isn't so big. I have been able to remove this limit at the
344        expense of backing off one optimization in certain circumstances. Normally,
345        when pcre_exec() would call its internal match() function recursively and
346        immediately return the result unconditionally, it uses a "tail recursion"
347        feature to save stack. However, when a subpattern that can match an empty
348        string has an unlimited repetition quantifier, it no longer makes this
349        optimization. That gives it a stack frame in which to save the data for
350        checking that an empty string has been matched. Previously this was taken
351        from the 1000-entry workspace that had been reserved. So now there is no
352        explicit limit, but more stack is used.
353    
354     8. Applied Daniel's patches to solve problems with the import/export magic
355        syntax that is required for Windows, and which was going wrong for the
356        pcreposix and pcrecpp parts of the library. These were overlooked when this
357        problem was solved for the main library.
358    
359     9. There were some crude static tests to avoid integer overflow when computing
360        the size of patterns that contain repeated groups with explicit upper
361        limits. As the maximum quantifier is 65535, the maximum group length was
362        set at 30,000 so that the product of these two numbers did not overflow a
363        32-bit integer. However, it turns out that people want to use groups that
364        are longer than 30,000 bytes (though not repeat them that many times).
365        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
366        made it possible to implement the integer overflow checks in a much more
367        dynamic way, which I have now done. The artificial limitation on group
368        length has been removed - we now have only the limit on the total length of
369        the compiled pattern, which depends on the LINK_SIZE setting.
370    
371    10. Fixed a bug in the documentation for get/copy named substring when
372        duplicate names are permitted. If none of the named substrings are set, the
373        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
374        empty string.
375    
376    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
377        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
378        because the ] is interpreted as the first data character and the
379        terminating ] is not found. PCRE has been made compatible with Perl in this
380        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
381        cause memory overwriting.
382    
383    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
384        string has been matched (to stop an infinite loop). It was not recognizing
385        a conditional subpattern that could match an empty string if that
386        subpattern was within another subpattern. For example, it looped when
387        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
388        condition was not nested. This bug has been fixed.
389    
390    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
391        past the start of the subject in the presence of bytes with the top bit
392        set, for example "\x8aBCD".
393    
394    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
395        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
396    
397    14. Optimized (?!) to (*FAIL).
398    
399    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
400        This restricts code points to be within the range 0 to 0x10FFFF, excluding
401        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
402        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
403        does: it's just the validity check that is more restrictive.
404    
405    16. Inserted checks for integer overflows during escape sequence (backslash)
406        processing, and also fixed erroneous offset values for syntax errors during
407        backslash processing.
408    
409    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
410        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
411    
412    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
413        caused an overrun.
414    
415    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
416        something other than just ASCII characters) inside a group that had an
417        unlimited repeat caused a loop at compile time (while checking to see
418        whether the group could match an empty string).
419    
420    20. Debugging a pattern containing \p or \P could cause a crash. For example,
421        [\P{Any}] did so. (Error in the code for printing property names.)
422    
423    21. An orphan \E inside a character class could cause a crash.
424    
425    22. A repeated capturing bracket such as (A)? could cause a wild memory
426        reference during compilation.
427    
428    23. There are several functions in pcre_compile() that scan along a compiled
429        expression for various reasons (e.g. to see if it's fixed length for look
430        behind). There were bugs in these functions when a repeated \p or \P was
431        present in the pattern. These operators have additional parameters compared
432        with \d, etc, and these were not being taken into account when moving along
433        the compiled data. Specifically:
434    
435        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
436            length.
437    
438        (b) An item such as \pL+ within a repeated group could cause crashes or
439            loops.
440    
441        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
442            "reference to non-existent subpattern" error.
443    
444        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
445    
446    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
447        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
448    
449    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
450    
451    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
452        character were causing crashes (broken optimization).
453    
454    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
455        \p or \P) caused a compile-time loop.
456    
457    28. More problems have arisen in unanchored patterns when CRLF is a valid line
458        break. For example, the unstudied pattern [\r\n]A does not match the string
459        "\r\nA" because change 7.0/46 below moves the current point on by two
460        characters after failing to match at the start. However, the pattern \nA
461        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
462        the same is true. There doesn't seem any very clean way out of this, but
463        what I have chosen to do makes the common cases work: PCRE now takes note
464        of whether there can be an explicit match for \r or \n anywhere in the
465        pattern, and if so, 7.0/46 no longer applies. As part of this change,
466        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
467        pattern has explicit CR or LF references.
468    
469    29. Added (*CR) etc for changing newline setting at start of pattern.
470    
471    
472    Version 7.2 19-Jun-07
473    ---------------------
474    
475     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
476        which is apparently normally available under Windows.
477    
478     2. Re-jig the pcregrep tests with different newline settings in an attempt
479        to make them independent of the local environment's newline setting.
480    
481     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
482    
483     4. Some of the "internals" tests were previously cut out when the link size
484        was not 2, because the output contained actual offsets. The recent new
485        "Z" feature of pcretest means that these can be cut out, making the tests
486        usable with all link sizes.
487    
488     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
489        stack recursion. This gives a massive performance boost under BSD, but just
490        a small improvement under Linux. However, it saves one field in the frame
491        in all cases.
492    
493     6. Added more features from the forthcoming Perl 5.10:
494    
495        (a) (?-n) (where n is a string of digits) is a relative subroutine or
496            recursion call. It refers to the nth most recently opened parentheses.
497    
498        (b) (?+n) is also a relative subroutine call; it refers to the nth next
499            to be opened parentheses.
500    
501        (c) Conditions that refer to capturing parentheses can be specified
502            relatively, for example, (?(-2)... or (?(+3)...
503    
504        (d) \K resets the start of the current match so that everything before
505            is not part of it.
506    
507        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
508    
509        (f) \g{name} is another synonym - part of Perl 5.10's unification of
510            reference syntax.
511    
512        (g) (?| introduces a group in which the numbering of parentheses in each
513            alternative starts with the same number.
514    
515        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
516    
517     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
518        PCRE_INFO_JCHANGED.
519    
520     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
521        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
522        for detecting groups that can match an empty string.
523    
524     9. A pattern with a very large number of alternatives (more than several
525        hundred) was running out of internal workspace during the pre-compile
526        phase, where pcre_compile() figures out how much memory will be needed. A
527        bit of new cunning has reduced the workspace needed for groups with
528        alternatives. The 1000-alternative test pattern now uses 12 bytes of
529        workspace instead of running out of the 4096 that are available.
530    
531    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
532    
533    11. Applied patch from Google to remove an optimization that didn't quite work.
534        The report of the bug said:
535    
536          pcrecpp::RE("a*").FullMatch("aaa") matches, while
537          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
538          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
539    
540    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
541        it matched the wrong number of bytes.
542    
543    
544    Version 7.1 24-Apr-07
545    ---------------------
546    
547     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
548        that is more "standard", making use of automake and other Autotools. There
549        is some re-arrangement of the files and adjustment of comments consequent
550        on this.
551    
552     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
553        for recursive directory scanning broke on some systems because the files
554        are not scanned in any specific order and on different systems the order
555        was different. A call to "sort" has been inserted into RunGrepTest for the
556        approprate test as a short-term fix. In the longer term there may be an
557        alternative.
558    
559     3. I had an email from Eric Raymond about problems translating some of PCRE's
560        man pages to HTML (despite the fact that I distribute HTML pages, some
561        people do their own conversions for various reasons). The problems
562        concerned the use of low-level troff macros .br and .in. I have therefore
563        removed all such uses from the man pages (some were redundant, some could
564        be replaced by .nf/.fi pairs). The 132html script that I use to generate
565        HTML has been updated to handle .nf/.fi and to complain if it encounters
566        .br or .in.
567    
568     4. Updated comments in configure.ac that get placed in config.h.in and also
569        arranged for config.h to be included in the distribution, with the name
570        config.h.generic, for the benefit of those who have to compile without
571        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
572    
573     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
574        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
575        makevp.bat for the current PCRE, using the additional files
576        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
577    
578     6. A Windows user reported a minor discrepancy with test 2, which turned out
579        to be caused by a trailing space on an input line that had got lost in his
580        copy. The trailing space was an accident, so I've just removed it.
581    
582     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
583        that is needed.
584    
585     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
586        as "const" (a) because they are and (b) because it helps the PHP
587        maintainers who have recently made a script to detect big data structures
588        in the php code that should be moved to the .rodata section. I remembered
589        to update Builducptable as well, so it won't revert if ucptable.h is ever
590        re-created.
591    
592     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
593        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
594        order to be able to cut out the UTF-8 tables in the latter when UTF-8
595        support is not required. This saves 1.5-2K of code, which is important in
596        some applications.
597    
598        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
599        so as not to refer to the tables, even though these functions will never be
600        called when UTF-8 support is disabled. Otherwise there are problems with a
601        shared library.
602    
603    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
604    
605        (a) It was defining its arguments as char * instead of void *.
606    
607        (b) It was assuming that all moves were upwards in memory; this was true
608            a long time ago when I wrote it, but is no longer the case.
609    
610        The emulated memove() is provided for those environments that have neither
611        memmove() nor bcopy(). I didn't think anyone used it these days, but that
612        is clearly not the case, as these two bugs were recently reported.
613    
614    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
615        and Detrail to create the HTML documentation, the .txt form of the man
616        pages, and it removes trailing spaces from listed files. It also creates
617        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
618        case, it wraps all the #defines with #ifndefs. This script should be run
619        before "make dist".
620    
621    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
622        with Unicode property support.
623    
624        (a) For a maximizing quantifier, if the two different cases of the
625            character were of different lengths in their UTF-8 codings (there are
626            some cases like this - I found 11), and the matching function had to
627            back up over a mixture of the two cases, it incorrectly assumed they
628            were both the same length.
629    
630        (b) When PCRE was configured to use the heap rather than the stack for
631            recursion during matching, it was not correctly preserving the data for
632            the other case of a UTF-8 character when checking ahead for a match
633            while processing a minimizing repeat. If the check also involved
634            matching a wide character, but failed, corruption could cause an
635            erroneous result when trying to check for a repeat of the original
636            character.
637    
638    13. Some tidying changes to the testing mechanism:
639    
640        (a) The RunTest script now detects the internal link size and whether there
641            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
642            values substituted by "configure". (The RunGrepTest script already did
643            this for UTF-8.) The configure.ac script no longer substitutes the
644            relevant variables.
645    
646        (b) The debugging options /B and /D in pcretest show the compiled bytecode
647            with length and offset values. This means that the output is different
648            for different internal link sizes. Test 2 is skipped for link sizes
649            other than 2 because of this, bypassing the problem. Unfortunately,
650            there was also a test in test 3 (the locale tests) that used /B and
651            failed for link sizes other than 2. Rather than cut the whole test out,
652            I have added a new /Z option to pcretest that replaces the length and
653            offset values with spaces. This is now used to make test 3 independent
654            of link size. (Test 2 will be tidied up later.)
655    
656    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
657        segmentation fault instead of returning the appropriate error message.
658    
659    15. In multiline mode when the newline sequence was set to "any", the pattern
660        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
661        This doesn't seem right; it now treats the CRLF combination as the line
662        ending, and so does not match in that case. It's only a pattern such as ^$
663        that would hit this one: something like ^ABC$ would have failed after \r
664        and then tried again after \r\n.
665    
666    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
667        in an attempt to make files that differ only in their line terminators
668        compare equal. This works on Linux.
669    
670    17. Under certain error circumstances pcregrep might try to free random memory
671        as it exited. This is now fixed, thanks to valgrind.
672    
673    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
674        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
675        was because its rules for how to advance for /g after matching an empty
676        string at the end of a line did not allow for this case. They now check for
677        it specially.
678    
679    20. pcretest is supposed to handle patterns and data of any length, by
680        extending its buffers when necessary. It was getting this wrong when the
681        buffer for a data line had to be extended.
682    
683    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
684        CRLF as a newline sequence.
685    
686    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
687        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
688        I have nevertheless tidied it up.
689    
690    23. Added some casts to kill warnings from HP-UX ia64 compiler.
691    
692    24. Added a man page for pcre-config.
693    
694    
695    Version 7.0 19-Dec-06
696    ---------------------
697    
698     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
699        moving to gcc 4.1.1.
700    
701     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
702        sys/time.h, which is documented as needed for this function. It doesn't
703        seem to matter on Linux, but it showed up on some releases of OS X.
704    
705     3. It seems that there are systems where bytes whose values are greater than
706        127 match isprint() in the "C" locale. The "C" locale should be the
707        default when a C program starts up. In most systems, only ASCII printing
708        characters match isprint(). This difference caused the output from pcretest
709        to vary, making some of the tests fail. I have changed pcretest so that:
710    
711        (a) When it is outputting text in the compiled version of a pattern, bytes
712            other than 32-126 are always shown as hex escapes.
713    
714        (b) When it is outputting text that is a matched part of a subject string,
715            it does the same, unless a different locale has been set for the match
716            (using the /L modifier). In this case, it uses isprint() to decide.
717    
718     4. Fixed a major bug that caused incorrect computation of the amount of memory
719        required for a compiled pattern when options that changed within the
720        pattern affected the logic of the preliminary scan that determines the
721        length. The relevant options are -x, and -i in UTF-8 mode. The result was
722        that the computed length was too small. The symptoms of this bug were
723        either the PCRE error "internal error: code overflow" from pcre_compile(),
724        or a glibc crash with a message such as "pcretest: free(): invalid next
725        size (fast)". Examples of patterns that provoked this bug (shown in
726        pcretest format) are:
727    
728          /(?-x: )/x
729          /(?x)(?-x: \s*#\s*)/
730          /((?i)[\x{c0}])/8
731          /(?i:[\x{c0}])/8
732    
733        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
734        is now done differently.
735    
736     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
737        wrapper classes; (b) implement a new function in the C++ scanner that is
738        more efficient than the old way of doing things because it avoids levels of
739        recursion in the regex matching; (c) add a paragraph to the documentation
740        for the FullMatch() function.
741    
742     6. The escape sequence \n was being treated as whatever was defined as
743        "newline". Not only was this contrary to the documentation, which states
744        that \n is character 10 (hex 0A), but it also went horribly wrong when
745        "newline" was defined as CRLF. This has been fixed.
746    
747     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
748        was being set to -1 for the "end of line" case (supposedly a value that no
749        character can have). Though this value is never used (the check for end of
750        line is "zero bytes in current character"), it caused compiler complaints.
751        I've changed it to 0xffffffff.
752    
753     8. In pcre_version.c, the version string was being built by a sequence of
754        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
755        string (as it is for production releases) called a macro with an empty
756        argument. The C standard says the result of this is undefined. The gcc
757        compiler treats it as an empty string (which was what was wanted) but it is
758        reported that Visual C gives an error. The source has been hacked around to
759        avoid this problem.
760    
761     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
762        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
763        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
764        of them did).
765    
766    10. Originally, pcretest opened its input and output without "b"; then I was
767        told that "b" was needed in some environments, so it was added for release
768        5.0 to both the input and output. (It makes no difference on Unix-like
769        systems.) Later I was told that it is wrong for the input on Windows. I've
770        now abstracted the modes into two macros, to make it easier to fiddle with
771        them, and removed "b" from the input mode under Windows.
772    
773    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
774    
775    12. Added -help and --help to pcretest as an official way of being reminded
776        of the options.
777    
778    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
779        and pcrecpp.cc because they annoy compilers at high warning levels.
780    
781    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
782    
783    15. Fixed an occurrence of == in configure.ac that should have been = (shell
784        scripts are not C programs :-) and which was not noticed because it works
785        on Linux.
786    
787    16. pcretest is supposed to handle any length of pattern and data line (as one
788        line or as a continued sequence of lines) by extending its input buffer if
789        necessary. This feature was broken for very long pattern lines, leading to
790        a string of junk being passed to pcre_compile() if the pattern was longer
791        than about 50K.
792    
793    17. I have done a major re-factoring of the way pcre_compile() computes the
794        amount of memory needed for a compiled pattern. Previously, there was code
795        that made a preliminary scan of the pattern in order to do this. That was
796        OK when PCRE was new, but as the facilities have expanded, it has become
797        harder and harder to keep it in step with the real compile phase, and there
798        have been a number of bugs (see for example, 4 above). I have now found a
799        cunning way of running the real compile function in a "fake" mode that
800        enables it to compute how much memory it would need, while actually only
801        ever using a few hundred bytes of working memory and without too many
802        tests of the mode. This should make future maintenance and development
803        easier. A side effect of this work is that the limit of 200 on the nesting
804        depth of parentheses has been removed (though this was never a serious
805        limitation, I suspect). However, there is a downside: pcre_compile() now
806        runs more slowly than before (30% or more, depending on the pattern). I
807        hope this isn't a big issue. There is no effect on runtime performance.
808    
809    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
810        newline (only possible for the last line of a file) and it was a
811        pattern that set a locale (followed by /Lsomething), pcretest crashed.
812    
813    19. Added additional timing features to pcretest. (1) The -tm option now times
814        matching only, not compiling. (2) Both -t and -tm can be followed, as a
815        separate command line item, by a number that specifies the number of
816        repeats to use when timing. The default is 50000; this gives better
817        precision, but takes uncomfortably long for very large patterns.
818    
819    20. Extended pcre_study() to be more clever in cases where a branch of a
820        subpattern has no definite first character. For example, (a*|b*)[cd] would
821        previously give no result from pcre_study(). Now it recognizes that the
822        first character must be a, b, c, or d.
823    
824    21. There was an incorrect error "recursive call could loop indefinitely" if
825        a subpattern (or the entire pattern) that was being tested for matching an
826        empty string contained only one non-empty item after a nested subpattern.
827        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
828        incorrectly, because the \d was being skipped in the check.
829    
830    22. The pcretest program now has a new pattern option /B and a command line
831        option -b, which is equivalent to adding /B to every pattern. This causes
832        it to show the compiled bytecode, without the additional information that
833        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
834        is the same as /B/I).
835    
836    23. A new optimization is now able automatically to treat some sequences such
837        as a*b as a*+b. More specifically, if something simple (such as a character
838        or a simple class like \d) has an unlimited quantifier, and is followed by
839        something that cannot possibly match the quantified thing, the quantifier
840        is automatically "possessified".
841    
842    24. A recursive reference to a subpattern whose number was greater than 39
843        went wrong under certain circumstances in UTF-8 mode. This bug could also
844        have affected the operation of pcre_study().
845    
846    25. Realized that a little bit of performance could be had by replacing
847        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
848    
849    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
850    
851    27. Possessive quantifiers such as a++ were previously implemented by turning
852        them into atomic groups such as ($>a+). Now they have their own opcodes,
853        which improves performance. This includes the automatically created ones
854        from 23 above.
855    
856    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
857        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
858        the first matched character to be a colon. This applied both to named and
859        numbered groups.
860    
861    29. The ucpinternal.h header file was missing its idempotency #ifdef.
862    
863    30. I was sent a "project" file called libpcre.a.dev which I understand makes
864        building PCRE on Windows easier, so I have included it in the distribution.
865    
866    31. There is now a check in pcretest against a ridiculously large number being
867        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
868        loop, the loop is abandoned.
869    
870    32. Forward references to subpatterns in conditions such as (?(2)...) where
871        subpattern 2 is defined later cause pcre_compile() to search forwards in
872        the pattern for the relevant set of parentheses. This search went wrong
873        when there were unescaped parentheses in a character class, parentheses
874        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
875    
876    33. "Subroutine" calls and backreferences were previously restricted to
877        referencing subpatterns earlier in the regex. This restriction has now
878        been removed.
879    
880    34. Added a number of extra features that are going to be in Perl 5.10. On the
881        whole, these are just syntactic alternatives for features that PCRE had
882        previously implemented using the Python syntax or my own invention. The
883        other formats are all retained for compatibility.
884    
885        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
886            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
887            also .NET compatible.
888    
889        (b) A recursion or subroutine call to a named group can now be defined as
890            (?&name) as well as (?P>name).
891    
892        (c) A backreference to a named group can now be defined as \k<name> or
893            \k'name' as well as (?P=name). The new forms, as well as being in Perl
894            5.10, are also .NET compatible.
895    
896        (d) A conditional reference to a named group can now use the syntax
897            (?(<name>) or (?('name') as well as (?(name).
898    
899        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
900            groups (named and numbered) that are never evaluated inline, but can be
901            called as "subroutines" from elsewhere. In effect, the DEFINE condition
902            is always false. There may be only one alternative in such a group.
903    
904        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
905            as the simple (?(R). The condition is true only if the most recent
906            recursion is that of the given number or name. It does not search out
907            through the entire recursion stack.
908    
909        (g) The escape \gN or \g{N} has been added, where N is a positive or
910            negative number, specifying an absolute or relative reference.
911    
912    35. Tidied to get rid of some further signed/unsigned compiler warnings and
913        some "unreachable code" warnings.
914    
915    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
916        things, this adds five new scripts.
917    
918    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
919        There were also incompatibilities regarding the handling of \Q..\E inside
920        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
921        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
922    
923    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
924        matches an empty string, and forcibly breaks the loop. There were bugs in
925        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
926        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
927        separate and independent bugs (that affected different cases) have been
928        fixed.
929    
930    39. Refactored the code to abolish the use of different opcodes for small
931        capturing bracket numbers. This is a tidy that I avoided doing when I
932        removed the limit on the number of capturing brackets for 3.5 back in 2001.
933        The new approach is not only tidier, it makes it possible to reduce the
934        memory needed to fix the previous bug (38).
935    
936    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
937        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
938        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
939        mode.
940    
941    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
942        report.
943    
944    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
945        copy construction and assignment in the C++ wrapper.
946    
947    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
948        couple of bugs that could have given wrong results in the "--newline=crlf"
949        case.
950    
951    44. Added a number of casts and did some reorganization of signed/unsigned int
952        variables following suggestions from Dair Grant. Also renamed the variable
953        "this" as "item" because it is a C++ keyword.
954    
955    45. Arranged for dftables to add
956    
957          #include "pcre_internal.h"
958    
959        to pcre_chartables.c because without it, gcc 4.x may remove the array
960        definition from the final binary if PCRE is built into a static library and
961        dead code stripping is activated.
962    
963    46. For an unanchored pattern, if a match attempt fails at the start of a
964        newline sequence, and the newline setting is CRLF or ANY, and the next two
965        characters are CRLF, advance by two characters instead of one.
966    
967    
968    Version 6.7 04-Jul-06
969    ---------------------
970    
971     1. In order to handle tests when input lines are enormously long, pcretest has
972        been re-factored so that it automatically extends its buffers when
973        necessary. The code is crude, but this _is_ just a test program. The
974        default size has been increased from 32K to 50K.
975    
976     2. The code in pcre_study() was using the value of the re argument before
977        testing it for NULL. (Of course, in any sensible call of the function, it
978        won't be NULL.)
979    
980     3. The memmove() emulation function in pcre_internal.h, which is used on
981        systems that lack both memmove() and bcopy() - that is, hardly ever -
982        was missing a "static" storage class specifier.
983    
984     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
985        containing an extended class (one that cannot be represented by a bitmap
986        because it contains high-valued characters or Unicode property items, e.g.
987        [\pZ]). Almost always one would set UTF-8 mode when processing such a
988        pattern, but PCRE should not loop if you do not (it no longer does).
989        [Detail: two cases were found: (a) a repeated subpattern containing an
990        extended class; (b) a recursive reference to a subpattern that followed a
991        previous extended class. It wasn't skipping over the extended class
992        correctly when UTF-8 mode was not set.]
993    
994     5. A negated single-character class was not being recognized as fixed-length
995        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
996        compile error "lookbehind assertion is not fixed length".
997    
998     6. The RunPerlTest auxiliary script was showing an unexpected difference
999        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1000        write a Perl script that can interpret lines of an input file either as
1001        byte characters or as UTF-8, which is what "perltest" was being required to
1002        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1003        can't do is switch easily at run time between having the "use utf8;" pragma
1004        or not. In the end, I fudged it by using the RunPerlTest script to insert
1005        "use utf8;" explicitly for the UTF-8 tests.
1006    
1007     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1008        the end of the subject string, contrary to the documentation and to what
1009        Perl does. This was true of both matching functions. Now it matches only at
1010        the start of the subject and immediately after *internal* newlines.
1011    
1012     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1013        a pointer to an int instead of a pointer to an unsigned long int. This
1014        caused problems on 64-bit systems.
1015    
1016     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1017        instance of the 'standard' template library not being so standard".
1018    
1019    10. There was no check on the number of named subpatterns nor the maximum
1020        length of a subpattern name. The product of these values is used to compute
1021        the size of the memory block for a compiled pattern. By supplying a very
1022        long subpattern name and a large number of named subpatterns, the size
1023        computation could be caused to overflow. This is now prevented by limiting
1024        the length of names to 32 characters, and the number of named subpatterns
1025        to 10,000.
1026    
1027    11. Subpatterns that are repeated with specific counts have to be replicated in
1028        the compiled pattern. The size of memory for this was computed from the
1029        length of the subpattern and the repeat count. The latter is limited to
1030        65535, but there was no limit on the former, meaning that integer overflow
1031        could in principle occur. The compiled length of a repeated subpattern is
1032        now limited to 30,000 bytes in order to prevent this.
1033    
1034    12. Added the optional facility to have named substrings with the same name.
1035    
1036    13. Added the ability to use a named substring as a condition, using the
1037        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1038        are numbers (not recommended). Forward references are permitted.
1039    
1040    14. Added forward references in named backreferences (if you see what I mean).
1041    
1042    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1043        pattern could run off the end of the subject. For example, the pattern
1044        "(?s)(.{1,5})"8 did this with the subject "ab".
1045    
1046    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1047        PCRE_CASELESS was set when matching characters that were quantified with ?
1048        or *.
1049    
1050    17. A character class other than a single negated character that had a minimum
1051        but no maximum quantifier - for example [ab]{6,} - was not handled
1052        correctly by pce_dfa_exec(). It would match only one character.
1053    
1054    18. A valid (though odd) pattern that looked like a POSIX character
1055        class but used an invalid character after [ (for example [[,abc,]]) caused
1056        pcre_compile() to give the error "Failed: internal error: code overflow" or
1057        in some cases to crash with a glibc free() error. This could even happen if
1058        the pattern terminated after [[ but there just happened to be a sequence of
1059        letters, a binary zero, and a closing ] in the memory that followed.
1060    
1061    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1062        over the years. Originally (before any Unicode support), just the bottom 8
1063        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1064        output from "man perlunicode" includes this:
1065    
1066          The regular expression compiler produces polymorphic opcodes.  That
1067          is, the pattern adapts to the data and automatically switches to
1068          the Unicode character scheme when presented with Unicode data--or
1069          instead uses a traditional byte scheme when presented with byte
1070          data.
1071    
1072        Sadly, a wide octal escape does not cause a switch, and in a string with
1073        no other multibyte characters, these octal escapes are treated as before.
1074        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1075        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1076        Unicode string.
1077    
1078        I have not perpetrated such confusion in PCRE. Up till now, it took just
1079        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1080        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1081        translate to the appropriate multibyte character.
1082    
1083    29. Applied some refactoring to reduce the number of warnings from Microsoft
1084        and Borland compilers. This has included removing the fudge introduced
1085        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1086        a warning about an unused variable.
1087    
1088    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1089        characters since release 4.0, because Perl (from release 5.004) does not.
1090        [Or at least, is documented not to: some releases seem to be in conflict
1091        with the documentation.] However, when a pattern was studied with
1092        pcre_study() and all its branches started with \s, PCRE still included VT
1093        as a possible starting character. Of course, this did no harm; it just
1094        caused an unnecessary match attempt.
1095    
1096    22. Removed a now-redundant internal flag bit that recorded the fact that case
1097        dependency changed within the pattern. This was once needed for "required
1098        byte" processing, but is no longer used. This recovers a now-scarce options
1099        bit. Also moved the least significant internal flag bit to the most-
1100        significant bit of the word, which was not previously used (hangover from
1101        the days when it was an int rather than a uint) to free up another bit for
1102        the future.
1103    
1104    23. Added support for CRLF line endings as well as CR and LF. As well as the
1105        default being selectable at build time, it can now be changed at runtime
1106        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1107        specify that it is scanning data with non-default line endings.
1108    
1109    24. Changed the definition of CXXLINK to make it agree with the definition of
1110        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1111    
1112    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1113        recursions. This makes a big different to stack usage for some patterns.
1114    
1115    26. If a subpattern containing a named recursion or subroutine reference such
1116        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1117        the space required for the compiled pattern went wrong and gave too small a
1118        value. Depending on the environment, this could lead to "Failed: internal
1119        error: code overflow at offset 49" or "glibc detected double free or
1120        corruption" errors.
1121    
1122    27. Applied patches from Google (a) to support the new newline modes and (b) to
1123        advance over multibyte UTF-8 characters in GlobalReplace.
1124    
1125    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1126        difference for some implementation of PCRE in some Windows version.
1127    
1128    29. Added some extra testing facilities to pcretest:
1129    
1130        \q<number>   in a data line sets the "match limit" value
1131        \Q<number>   in a data line sets the "match recursion limt" value
1132        -S <number>  sets the stack size, where <number> is in megabytes
1133    
1134        The -S option isn't available for Windows.
1135    
1136    
1137    Version 6.6 06-Feb-06
1138    ---------------------
1139    
1140     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1141        in pcreposix.h. I have copied the definition from pcre.h.
1142    
1143     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1144        because pcre.h is no longer a built file.
1145    
1146     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1147        not normally included in the compiled code.
1148    
1149    
1150    Version 6.5 01-Feb-06
1151    ---------------------
1152    
1153     1. When using the partial match feature with pcre_dfa_exec(), it was not
1154        anchoring the second and subsequent partial matches at the new starting
1155        point. This could lead to incorrect results. For example, with the pattern
1156        /1234/, partially matching against "123" and then "a4" gave a match.
1157    
1158     2. Changes to pcregrep:
1159    
1160        (a) All non-match returns from pcre_exec() were being treated as failures
1161            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1162            error message is output. Some extra information is given for the
1163            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1164            probably the only errors that are likely to be caused by users (by
1165            specifying a regex that has nested indefinite repeats, for instance).
1166            If there are more than 20 of these errors, pcregrep is abandoned.
1167    
1168        (b) A binary zero was treated as data while matching, but terminated the
1169            output line if it was written out. This has been fixed: binary zeroes
1170            are now no different to any other data bytes.
1171    
1172        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1173            used to set a locale for matching. The --locale=xxxx long option has
1174            been added (no short equivalent) to specify a locale explicitly on the
1175            pcregrep command, overriding the environment variables.
1176    
1177        (d) When -B was used with -n, some line numbers in the output were one less
1178            than they should have been.
1179    
1180        (e) Added the -o (--only-matching) option.
1181    
1182        (f) If -A or -C was used with -c (count only), some lines of context were
1183            accidentally printed for the final match.
1184    
1185        (g) Added the -H (--with-filename) option.
1186    
1187        (h) The combination of options -rh failed to suppress file names for files
1188            that were found from directory arguments.
1189    
1190        (i) Added the -D (--devices) and -d (--directories) options.
1191    
1192        (j) Added the -F (--fixed-strings) option.
1193    
1194        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1195    
1196        (l) Added the --colo(u)r option.
1197    
1198        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1199            is not present by default.
1200    
1201     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1202        items such as (?R) or (?1), when the recursion could match a number of
1203        alternatives. If it matched one of the alternatives, but subsequently,
1204        outside the recursion, there was a failure, the code tried to back up into
1205        the recursion. However, because of the way PCRE is implemented, this is not
1206        possible, and the result was an incorrect result from the match.
1207    
1208        In order to prevent this happening, the specification of recursion has
1209        been changed so that all such subpatterns are automatically treated as
1210        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1211    
1212     4. I had overlooked the fact that, in some locales, there are characters for
1213        which isalpha() is true but neither isupper() nor islower() are true. In
1214        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1215        and ordfeminine) are like this. This affected the treatment of \w and \W
1216        when they appeared in character classes, but not when they appeared outside
1217        a character class. The bit map for "word" characters is now created
1218        separately from the results of isalnum() instead of just taking it from the
1219        upper, lower, and digit maps. (Plus the underscore character, of course.)
1220    
1221     5. The above bug also affected the handling of POSIX character classes such as
1222        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1223        permanent tables. Instead, the bit maps for such a class were previously
1224        created as the appropriate unions of the upper, lower, and digit bitmaps.
1225        Now they are created by subtraction from the [[:word:]] class, which has
1226        its own bitmap.
1227    
1228     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1229        It is created by subtracting the vertical space characters (\x09, \x0a,
1230        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1231        subtraction was done in the overall bitmap for a character class, meaning
1232        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1233        be recognized. This bug has been fixed.
1234    
1235     7. Patches from the folks at Google:
1236    
1237          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1238          real life, but is still worth protecting against".
1239    
1240          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1241          regular expressions".
1242    
1243          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1244          have it.
1245    
1246          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1247          "configure" and the latter not, in order to fix a problem somebody had
1248          with compiling the Arg class on HP-UX.
1249    
1250          (e) Improve the error-handling of the C++ wrapper a little bit.
1251    
1252          (f) New tests for checking recursion limiting.
1253    
1254     8. The pcre_memmove() function, which is used only if the environment does not
1255        have a standard memmove() function (and is therefore rarely compiled),
1256        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1257        returning a result (though PCRE never actually uses the result).
1258    
1259     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1260        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1261        returned instead of calling malloc() with an overflowing number that would
1262        most likely cause subsequent chaos.
1263    
1264    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1265    
1266    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1267        with this option is matched, the nmatch and pmatch options of regexec() are
1268        ignored.
1269    
1270    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1271        provided in case anyone wants to the the POSIX interface with UTF-8
1272        strings.
1273    
1274    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1275        C++ linking (needed for some HP-UX environments).
1276    
1277    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1278        (unused parameter) and in the pcre_printint() function (omitted "default"
1279        switch label when the default is to do nothing).
1280    
1281    15. Added some code to make it possible, when PCRE is compiled as a C++
1282        library, to replace subject pointers for pcre_exec() with a smart pointer
1283        class, thus making it possible to process discontinuous strings.
1284    
1285    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1286        much the same function. They were added by different people who were trying
1287        to make PCRE easy to compile on non-Unix systems. It has been suggested
1288        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1289        for compiling on Windows systems. I have therefore replaced it with
1290        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1291        defaults to "extern" for C or "extern C" for C++, which works fine on
1292        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1293        SCOPE with something explicit in config.h. In addition:
1294    
1295        (a) pcreposix.h still had just "extern" instead of either of these macros;
1296            I have replaced it with PCRE_DATA_SCOPE.
1297    
1298        (b) Functions such as _pcre_xclass(), which are internal to the library,
1299            but external in the C sense, all had PCRE_EXPORT in their definitions.
1300            This is apparently wrong for the Windows case, so I have removed it.
1301            (It makes no difference on Unix-like systems.)
1302    
1303    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1304        of recursive calls to match(). This is different to MATCH_LIMIT because
1305        that limits the total number of calls to match(), not all of which increase
1306        the depth of recursion. Limiting the recursion depth limits the amount of
1307        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1308        when PCRE is compiled, and changed at run time. A patch from Google adds
1309        this functionality to the C++ interface.
1310    
1311    18. Changes to the handling of Unicode character properties:
1312    
1313        (a) Updated the table to Unicode 4.1.0.
1314    
1315        (b) Recognize characters that are not in the table as "Cn" (undefined).
1316    
1317        (c) I revised the way the table is implemented to a much improved format
1318            which includes recognition of ranges. It now supports the ranges that
1319            are defined in UnicodeData.txt, and it also amalgamates other
1320            characters into ranges. This has reduced the number of entries in the
1321            table from around 16,000 to around 3,000, thus reducing its size
1322            considerably. I realized I did not need to use a tree structure after
1323            all - a binary chop search is just as efficient. Having reduced the
1324            number of entries, I extended their size from 6 bytes to 8 bytes to
1325            allow for more data.
1326    
1327        (d) Added support for Unicode script names via properties such as \p{Han}.
1328    
1329    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1330        matching that character.
1331    
1332    20. When matching a repeated Unicode property with a minimum greater than zero,
1333        (for example \pL{2,}), PCRE could look past the end of the subject if it
1334        reached it while seeking the minimum number of characters. This could
1335        happen only if some of the characters were more than one byte long, because
1336        there is a check for at least the minimum number of bytes.
1337    
1338    21. Refactored the implementation of \p and \P so as to be more general, to
1339        allow for more different types of property in future. This has changed the
1340        compiled form incompatibly. Anybody with saved compiled patterns that use
1341        \p or \P will have to recompile them.
1342    
1343    22. Added "Any" and "L&" to the supported property types.
1344    
1345    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1346        but give a compile time error if the value is greater than 0xff.
1347    
1348    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1349        accidentally not being installed or uninstalled.
1350    
1351    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1352        made were to insert the current release number. This seemed silly, because
1353        it made things harder for people building PCRE on systems that don't run
1354        "configure". I have turned pcre.h into a distributed file, no longer built
1355        by "configure", with the version identification directly included. There is
1356        no longer a pcre.h.in file.
1357    
1358        However, this change necessitated a change to the pcre-config script as
1359        well. It is built from pcre-config.in, and one of the substitutions was the
1360        release number. I have updated configure.ac so that ./configure now finds
1361        the release number by grepping pcre.h.
1362    
1363    26. Added the ability to run the tests under valgrind.
1364    
1365    
1366    Version 6.4 05-Sep-05
1367    ---------------------
1368    
1369     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1370        "--" to be printed when multiple files were scanned, even when none of the
1371        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1372        consider it to be a bug, and have restored the previous behaviour.
1373    
1374     2. A couple of code tidies to get rid of compiler warnings.
1375    
1376     3. The pcretest program used to cheat by referring to symbols in the library
1377        whose names begin with _pcre_. These are internal symbols that are not
1378        really supposed to be visible externally, and in some environments it is
1379        possible to suppress them. The cheating is now confined to including
1380        certain files from the library's source, which is a bit cleaner.
1381    
1382     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1383        file's purpose clearer.
1384    
1385     5. Reorganized pcre_ucp_findchar().
1386    
1387    
1388    Version 6.3 15-Aug-05
1389    ---------------------
1390    
1391     1. The file libpcre.pc.in did not have general read permission in the tarball.
1392    
1393     2. There were some problems when building without C++ support:
1394    
1395        (a) If C++ support was not built, "make install" and "make test" still
1396            tried to test it.
1397    
1398        (b) There were problems when the value of CXX was explicitly set. Some
1399            changes have been made to try to fix these, and ...
1400    
1401        (c) --disable-cpp can now be used to explicitly disable C++ support.
1402    
1403        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1404            backslash in a target when C++ was disabled. This confuses some
1405            versions of "make", apparently. Using an intermediate variable solves
1406            this. (Same for CPP_LOBJ.)
1407    
1408     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1409        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1410        necessary on certain architectures.
1411    
1412     4. Added a setting of -export-symbols-regex to the link command to remove
1413        those symbols that are exported in the C sense, but actually are local
1414        within the library, and not documented. Their names all begin with
1415        "_pcre_". This is not a perfect job, because (a) we have to except some
1416        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1417        available (and never for static libraries). I have made a note to try to
1418        find a way round (a) in the future.
1419    
1420    
1421    Version 6.2 01-Aug-05
1422    ---------------------
1423    
1424     1. There was no test for integer overflow of quantifier values. A construction
1425        such as {1111111111111111} would give undefined results. What is worse, if
1426        a minimum quantifier for a parenthesized subpattern overflowed and became
1427        negative, the calculation of the memory size went wrong. This could have
1428        led to memory overwriting.
1429    
1430     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1431    
1432     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1433        operating environments where this matters.
1434    
1435     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1436        PCRE options from within the C++ wrapper.
1437    
1438     5. Named capturing subpatterns were not being correctly counted when a pattern
1439        was compiled. This caused two problems: (a) If there were more than 100
1440        such subpatterns, the calculation of the memory needed for the whole
1441        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1442        back references of the form \12, where the number was greater than 9, were
1443        not recognized as back references, even though there were sufficient
1444        previous subpatterns.
1445    
1446     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1447        versions of gcc, e.g. 2.95.4.
1448    
1449    
1450    Version 6.1 21-Jun-05
1451    ---------------------
1452    
1453     1. There was one reference to the variable "posix" in pcretest.c that was not
1454        surrounded by "#if !defined NOPOSIX".
1455    
1456     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1457        the cross-check on the old pcre_info() function, for the benefit of the
1458        cut-down version of PCRE that is currently imported into Exim.
1459    
1460     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1461        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1462        patterns that start (?i) but I don't think that matters. The use of (?i) is
1463        just an example; this all applies to the other options as well.
1464    
1465     4. Since libtool seems to echo the compile commands it is issuing, the output
1466        from "make" can be reduced a bit by putting "@" in front of each libtool
1467        compile command.
1468    
1469     5. Patch from the folks at Google for configure.in to be a bit more thorough
1470        in checking for a suitable C++ installation before trying to compile the
1471        C++ stuff. This should fix a reported problem when a compiler was present,
1472        but no suitable headers.
1473    
1474     6. The man pages all had just "PCRE" as their title. I have changed them to
1475        be the relevant file name. I have also arranged that these names are
1476        retained in the file doc/pcre.txt, which is a concatenation in text format
1477        of all the man pages except the little individual ones for each function.
1478    
1479     7. The NON-UNIX-USE file had not been updated for the different set of source
1480        files that come with release 6. I also added a few comments about the C++
1481        wrapper.
1482    
1483    
1484    Version 6.0 07-Jun-05
1485    ---------------------
1486    
1487     1. Some minor internal re-organization to help with my DFA experiments.
1488    
1489     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1490        didn't matter for the library itself when fully configured, but did matter
1491        when compiling without UCP support, or within Exim, where the ucp files are
1492        not imported.
1493    
1494     3. Refactoring of the library code to split up the various functions into
1495        different source modules. The addition of the new DFA matching code (see
1496        below) to a single monolithic source would have made it really too
1497        unwieldy, quite apart from causing all the code to be include in a
1498        statically linked application, when only some functions are used. This is
1499        relevant even without the DFA addition now that patterns can be compiled in
1500        one application and matched in another.
1501    
1502        The downside of splitting up is that there have to be some external
1503        functions and data tables that are used internally in different modules of
1504        the library but which are not part of the API. These have all had their
1505        names changed to start with "_pcre_" so that they are unlikely to clash
1506        with other external names.
1507    
1508     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1509        a different (DFA) algorithm. Although it is slower than the original
1510        function, it does have some advantages for certain types of matching
1511        problem.
1512    
1513     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1514        including restarting after a partial match.
1515    
1516     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1517        defined when compiling for Windows was sent to me. I have put it into the
1518        code, though I have no means of testing or verifying it.
1519    
1520     7. Added the pcre_refcount() auxiliary function.
1521    
1522     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1523        match before or at the first newline in the subject string. In pcretest,
1524        the /f option on a pattern can be used to set this.
1525    
1526     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1527        would behave wrongly. This has been present in PCRE since release 4.0.
1528    
1529    10. A number of changes to the pcregrep command:
1530    
1531        (a) Refactored how -x works; insert ^(...)$ instead of setting
1532            PCRE_ANCHORED and checking the length, in preparation for adding
1533            something similar for -w.
1534    
1535        (b) Added the -w (match as a word) option.
1536    
1537        (c) Refactored the way lines are read and buffered so as to have more
1538            than one at a time available.
1539    
1540        (d) Implemented a pcregrep test script.
1541    
1542        (e) Added the -M (multiline match) option. This allows patterns to match
1543            over several lines of the subject. The buffering ensures that at least
1544            8K, or the rest of the document (whichever is the shorter) is available
1545            for matching (and similarly the previous 8K for lookbehind assertions).
1546    
1547        (f) Changed the --help output so that it now says
1548    
1549              -w, --word-regex(p)
1550    
1551            instead of two lines, one with "regex" and the other with "regexp"
1552            because that confused at least one person since the short forms are the
1553            same. (This required a bit of code, as the output is generated
1554            automatically from a table. It wasn't just a text change.)
1555    
1556        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1557            option but starts with a hyphen. Could be a pattern or a path name
1558            starting with a hyphen, for instance.
1559    
1560        (h) "-" can be given as a file name to represent stdin.
1561    
1562        (i) When file names are being printed, "(standard input)" is used for
1563            the standard input, for compatibility with GNU grep. Previously
1564            "<stdin>" was used.
1565    
1566        (j) The option --label=xxx can be used to supply a name to be used for
1567            stdin when file names are being printed. There is no short form.
1568    
1569        (k) Re-factored the options decoding logic because we are going to add
1570            two more options that take data. Such options can now be given in four
1571            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1572    
1573        (l) Added the -A, -B, and -C options for requesting that lines of context
1574            around matches be printed.
1575    
1576        (m) Added the -L option to print the names of files that do not contain
1577            any matching lines, that is, the complement of -l.
1578    
1579        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1580            continue to scan other files.
1581    
1582        (o) The -s option was incorrectly implemented. For compatibility with other
1583            greps, it now suppresses the error message for a non-existent or non-
1584            accessible file (but not the return code). There is a new option called
1585            -q that suppresses the output of matching lines, which was what -s was
1586            previously doing.
1587    
1588        (p) Added --include and --exclude options to specify files for inclusion
1589            and exclusion when recursing.
1590    
1591    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1592        Hopefully, it now does.
1593    
1594    12. Missing cast in pcre_study().
1595    
1596    13. Added an "uninstall" target to the makefile.
1597    
1598    14. Replaced "extern" in the function prototypes in Makefile.in with
1599        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1600        world, but is set differently for Windows.
1601    
1602    15. Added a second compiling function called pcre_compile2(). The only
1603        difference is that it has an extra argument, which is a pointer to an
1604        integer error code. When there is a compile-time failure, this is set
1605        non-zero, in addition to the error test pointer being set to point to an
1606        error message. The new argument may be NULL if no error number is required
1607        (but then you may as well call pcre_compile(), which is now just a
1608        wrapper). This facility is provided because some applications need a
1609        numeric error indication, but it has also enabled me to tidy up the way
1610        compile-time errors are handled in the POSIX wrapper.
1611    
1612    16. Added VPATH=.libs to the makefile; this should help when building with one
1613        prefix path and installing with another. (Or so I'm told by someone who
1614        knows more about this stuff than I do.)
1615    
1616    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1617        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1618        match everything, including newlines. This is not POSIX-compatible, but
1619        somebody wanted the feature. From pcretest it can be activated by using
1620        both the P and the s flags.
1621    
1622    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1623    
1624    19. libpcre.pc was being incorrectly installed as executable.
1625    
1626    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1627        it now also looks for '\r' so that it will work unmodified on Windows.
1628    
1629    21. Added Google's contributed C++ wrapper to the distribution.
1630    
1631    22. Added some untidy missing memory free() calls in pcretest, to keep
1632        Electric Fence happy when testing.
1633    
1634    
1635    
1636    Version 5.0 13-Sep-04
1637    ---------------------
1638    
1639     1. Internal change: literal characters are no longer packed up into items
1640        containing multiple characters in a single byte-string. Each character
1641        is now matched using a separate opcode. However, there may be more than one
1642        byte in the character in UTF-8 mode.
1643    
1644     2. The pcre_callout_block structure has two new fields: pattern_position and
1645        next_item_length. These contain the offset in the pattern to the next match
1646        item, and its length, respectively.
1647    
1648     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1649        insertion of callouts before each pattern item. Added the /C option to
1650        pcretest to make use of this.
1651    
1652     4. On the advice of a Windows user, the lines
1653    
1654          #if defined(_WIN32) || defined(WIN32)
1655          _setmode( _fileno( stdout ), 0x8000 );
1656          #endif  /* defined(_WIN32) || defined(WIN32) */
1657    
1658        have been added to the source of pcretest. This apparently does useful
1659        magic in relation to line terminators.
1660    
1661     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1662        for the benefit of those environments where the "b" makes a difference.
1663    
1664     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1665        to know about it. I have put a hack into configure.in that adds in code
1666        to set GCC=yes if CC=icc. This seems to end up at a point in the
1667        generated configure script that is early enough to affect the setting of
1668        compiler options, which is what is needed, but I have no means of testing
1669        whether it really works. (The user who reported this had patched the
1670        generated configure script, which of course I cannot do.)
1671    
1672        LATER: After change 22 below (new libtool files), the configure script
1673        seems to know about icc (and also ecc). Therefore, I have commented out
1674        this hack in configure.in.
1675    
1676     7. Added support for pkg-config (2 patches were sent in).
1677    
1678     8. Negated POSIX character classes that used a combination of internal tables
1679        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1680        [[:^ascii]]. Typically, they would match almost any characters. The other
1681        POSIX classes were not broken in this way.
1682    
1683     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1684        to find the match, as PCRE was deluded into thinking that the match had to
1685        start at the start point or following a newline. The same bug applied to
1686        patterns with negative forward assertions or any backward assertions
1687        preceding ".*" at the start, unless the pattern required a fixed first
1688        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1689    
1690    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1691        starting at the last subject character, bytes beyond the end of the subject
1692        string were read.
1693    
1694    11. Renamed the variable "class" as "classbits" to make life easier for C++
1695        users. (Previously there was a macro definition, but it apparently wasn't
1696        enough.)
1697    
1698    12. Added the new field "tables" to the extra data so that tables can be passed
1699        in at exec time, or the internal tables can be re-selected. This allows
1700        a compiled regex to be saved and re-used at a later time by a different
1701        program that might have everything at different addresses.
1702    
1703    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1704        -R library as well as a -L library.
1705    
1706    14. The debugging options of pcretest (-d on the command line or D on a
1707        pattern) showed incorrect output for anything following an extended class
1708        that contained multibyte characters and which was followed by a quantifier.
1709    
1710    15. Added optional support for general category Unicode character properties
1711        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1712        support. It adds about 90K to the size of the library. The meanings of the
1713        inbuilt class escapes such as \d and \s have NOT been changed.
1714    
1715    16. Updated pcredemo.c to include calls to free() to release the memory for the
1716        compiled pattern.
1717    
1718    17. The generated file chartables.c was being created in the source directory
1719        instead of in the building directory. This caused the build to fail if the
1720        source directory was different from the building directory, and was
1721        read-only.
1722    
1723    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1724        file. No doubt somebody will tell me if they don't make sense... Also added
1725        Dan Mooney's comments about building on OpenVMS.
1726    
1727    19. Added support for partial matching via the PCRE_PARTIAL option for
1728        pcre_exec() and the \P data escape in pcretest.
1729    
1730    20. Extended pcretest with 3 new pattern features:
1731    
1732        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1733              write the compiled pattern to the file whose name is "rest-of-line".
1734              This is a straight binary dump of the data, with the saved pointer to
1735              the character tables forced to be NULL. The study data, if any, is
1736              written too. After writing, pcretest reads a new pattern.
1737    
1738        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1739              compiled pattern from the given file. There must not be any
1740              occurrences of "<" in the file name (pretty unlikely); if there are,
1741              pcretest will instead treat the initial "<" as a pattern delimiter.
1742              After reading in the pattern, pcretest goes on to read data lines as
1743              usual.
1744    
1745        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1746              and 16-bit fields in a compiled pattern, to simulate a pattern that
1747              was compiled on a host of opposite endianness.
1748    
1749    21. The pcre-exec() function can now cope with patterns that were compiled on
1750        hosts of opposite endianness, with this restriction:
1751    
1752          As for any compiled expression that is saved and used later, the tables
1753          pointer field cannot be preserved; the extra_data field in the arguments
1754          to pcre_exec() should be used to pass in a tables address if a value
1755          other than the default internal tables were used at compile time.
1756    
1757    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1758        now diagnosed as an error. Previously, most of the time, a negative number
1759        would have been treated as zero, but if in addition "ovector" was passed as
1760        NULL, a crash could occur.
1761    
1762    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1763        new versions from the libtool 1.5 distribution (the last one is a copy of
1764        a file called libtool.m4). This seems to have fixed the need to patch
1765        "configure" to support Darwin 1.3 (which I used to do). However, I still
1766        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1767        workstation).
1768    
1769    24. Changed the PCRE licence to be the more standard "BSD" licence.
1770    
1771    
1772    Version 4.5 01-Dec-03
1773    ---------------------
1774    
1775     1. There has been some re-arrangement of the code for the match() function so
1776        that it can be compiled in a version that does not call itself recursively.
1777        Instead, it keeps those local variables that need separate instances for
1778        each "recursion" in a frame on the heap, and gets/frees frames whenever it
1779        needs to "recurse". Keeping track of where control must go is done by means
1780        of setjmp/longjmp. The whole thing is implemented by a set of macros that
1781        hide most of the details from the main code, and operates only if
1782        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1783        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1784        operating.
1785    
1786        To make it easier for callers to provide specially tailored get/free
1787        functions for this usage, two new functions, pcre_stack_malloc, and
1788        pcre_stack_free, are used. They are always called in strict stacking order,
1789        and the size of block requested is always the same.
1790    
1791        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1792        PCRE has been compiled to use the stack or the heap for recursion. The
1793        -C option of pcretest uses this to show which version is compiled.
1794    
1795        A new data escape \S, is added to pcretest; it causes the amounts of store
1796        obtained and freed by both kinds of malloc/free at match time to be added
1797        to the output.
1798    
1799     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1800        what's available on my current Linux desktop machine.
1801    
1802     3. When matching a UTF-8 string, the test for a valid string at the start has
1803        been extended. If start_offset is not zero, PCRE now checks that it points
1804        to a byte that is the start of a UTF-8 character. If not, it returns
1805        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1806        this is necessary because there may be backward assertions in the pattern.
1807        When matching the same subject several times, it may save resources to use
1808        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1809    
1810     4. The code for checking the validity of UTF-8 strings has been tightened so
1811        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1812        containing "overlong sequences".
1813    
1814     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1815        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1816        should have been "&", but it just so happened that all the cases this let
1817        through by mistake were picked up later in the function.
1818    
1819     6. I had used a variable called "isblank" - this is a C99 function, causing
1820        some compilers to warn. To avoid this, I renamed it (as "blankclass").
1821    
1822     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1823        prompting; (b) run "./pcretest /dev/null" at the start of the test script
1824        so the version is shown; (c) stop "make test" echoing "./RunTest".
1825    
1826     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1827    
1828     9. The prototype for memmove() for systems that don't have it was using
1829        size_t, but the inclusion of the header that defines size_t was later. I've
1830        moved the #includes for the C headers earlier to avoid this.
1831    
1832    10. Added some adjustments to the code to make it easier to compiler on certain
1833        special systems:
1834    
1835          (a) Some "const" qualifiers were missing.
1836          (b) Added the macro EXPORT before all exported functions; by default this
1837              is defined to be empty.
1838          (c) Changed the dftables auxiliary program (that builds chartables.c) so
1839              that it reads its output file name as an argument instead of writing
1840              to the standard output and assuming this can be redirected.
1841    
1842    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1843        class containing characters with values greater than 255, PCRE compilation
1844        went into a loop.
1845    
1846    12. A recursive reference to a subpattern that was within another subpattern
1847        that had a minimum quantifier of zero caused PCRE to crash. For example,
1848        (x(y(?2))z)? provoked this bug with a subject that got as far as the
1849        recursion. If the recursively-called subpattern itself had a zero repeat,
1850        that was OK.
1851    
1852    13. In pcretest, the buffer for reading a data line was set at 30K, but the
1853        buffer into which it was copied (for escape processing) was still set at
1854        1024, so long lines caused crashes.
1855    
1856    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1857        "internal error: code overflow...". This applied to any character class
1858        that was followed by a possessive quantifier.
1859    
1860    15. Modified the Makefile to add libpcre.la as a prerequisite for
1861        libpcreposix.la because I was told this is needed for a parallel build to
1862        work.
1863    
1864    16. If a pattern that contained .* following optional items at the start was
1865        studied, the wrong optimizing data was generated, leading to matching
1866        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1867        matching string must start with a or b or c. The correct conclusion for
1868        this pattern is that a match can start with any character.
1869    
1870    
1871    Version 4.4 13-Aug-03
1872    ---------------------
1873    
1874     1. In UTF-8 mode, a character class containing characters with values between
1875        127 and 255 was not handled correctly if the compiled pattern was studied.
1876        In fixing this, I have also improved the studying algorithm for such
1877        classes (slightly).
1878    
1879     2. Three internal functions had redundant arguments passed to them. Removal
1880        might give a very teeny performance improvement.
1881    
1882     3. Documentation bug: the value of the capture_top field in a callout is *one
1883        more than* the number of the hightest numbered captured substring.
1884    
1885     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1886        in incorrectly linking with a previously installed version. They now link
1887        explicitly with libpcre.la.
1888    
1889     5. configure.in no longer needs to recognize Cygwin specially.
1890    
1891     6. A problem in pcre.in for Windows platforms is fixed.
1892    
1893     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1894        pcretest, it used to include the size of the study block as part of its
1895        output. Unfortunately, the structure contains a field that has a different
1896        size on different hardware architectures. This meant that the tests that
1897        showed this size failed. As the block is currently always of a fixed size,
1898        this information isn't actually particularly useful in pcretest output, so
1899        I have just removed it.
1900    
1901     8. Three pre-processor statements accidentally did not start in column 1.
1902        Sadly, there are *still* compilers around that complain, even though
1903        standard C has not required this for well over a decade. Sigh.
1904    
1905     9. In pcretest, the code for checking callouts passed small integers in the
1906        callout_data field, which is a void * field. However, some picky compilers
1907        complained about the casts involved for this on 64-bit systems. Now
1908        pcretest passes the address of the small integer instead, which should get
1909        rid of the warnings.
1910    
1911    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1912        both compile and run time, and gives an error if an invalid UTF-8 sequence
1913        is found. There is a option for disabling this check in cases where the
1914        string is known to be correct and/or the maximum performance is wanted.
1915    
1916    11. In response to a bug report, I changed one line in Makefile.in from
1917    
1918            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1919        to
1920            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1921    
1922        to look similar to other lines, but I have no way of telling whether this
1923        is the right thing to do, as I do not use Windows. No doubt I'll get told
1924        if it's wrong...
1925    
1926    
1927  Version 4.3 21-May-03  Version 4.3 21-May-03
1928  ---------------------  ---------------------
1929    

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