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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 8.0 02 Jul-08
5    ---------------------
6    
7    1.  Replaced UCP searching code with optimized version as implemented for Ad
8        Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
9        stage table and inline lookup instead of a function, giving speed ups of 2
10        to 5 times on some simple patterns that I tested. Permission was given to
11        distribute the MultiStage2.py script that generates the tables (it's not in
12        the tarball, but is in the Subversion repository).
13    
14    2.  Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
15        scripts.
16    
17    3.  Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
18        a group with a zero qualifier. The result of the study could be incorrect,
19        or the function might crash, depending on the pattern.
20    
21    4.  Caseless matching was not working for non-ASCII characters in back
22        references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23        It now works when Unicode Property Support is available.
24    
25    5.  In pcretest, an escape such as \x{de} in the data was always generating
26        a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
27        non-UTF-8 mode. If the value is greater than 255, it gives a warning about
28        truncation.
29    
30    
31    Version 7.7 07-May-08
32    ---------------------
33    
34    1.  Applied Craig's patch to sort out a long long problem: "If we can't convert
35        a string to a long long, pretend we don't even have a long long." This is
36        done by checking for the strtoq, strtoll, and _strtoi64 functions.
37    
38    2.  Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
39        pre-7.6 versions, which defined a global no_arg variable instead of putting
40        it in the RE class. (See also #8 below.)
41    
42    3.  Remove a line of dead code, identified by coverity and reported by Nuno
43        Lopes.
44    
45    4.  Fixed two related pcregrep bugs involving -r with --include or --exclude:
46    
47        (1) The include/exclude patterns were being applied to the whole pathnames
48            of files, instead of just to the final components.
49    
50        (2) If there was more than one level of directory, the subdirectories were
51            skipped unless they satisfied the include/exclude conditions. This is
52            inconsistent with GNU grep (and could even be seen as contrary to the
53            pcregrep specification - which I improved to make it absolutely clear).
54            The action now is always to scan all levels of directory, and just
55            apply the include/exclude patterns to regular files.
56    
57    5.  Added the --include_dir and --exclude_dir patterns to pcregrep, and used
58        --exclude_dir in the tests to avoid scanning .svn directories.
59    
60    6.  Applied Craig's patch to the QuoteMeta function so that it escapes the
61        NUL character as backslash + 0 rather than backslash + NUL, because PCRE
62        doesn't support NULs in patterns.
63    
64    7.  Added some missing "const"s to declarations of static tables in
65        pcre_compile.c and pcre_dfa_exec.c.
66    
67    8.  Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
68        caused by fix #2  above. (Subsequently also a second patch to fix the
69        first patch. And a third patch - this was a messy problem.)
70    
71    9.  Applied Craig's patch to remove the use of push_back().
72    
73    10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
74        matching function regexec().
75    
76    11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
77        which, however, unlike Perl's \g{...}, are subroutine calls, not back
78        references. PCRE supports relative numbers with this syntax (I don't think
79        Oniguruma does).
80    
81    12. Previously, a group with a zero repeat such as (...){0} was completely
82        omitted from the compiled regex. However, this means that if the group
83        was called as a subroutine from elsewhere in the pattern, things went wrong
84        (an internal error was given). Such groups are now left in the compiled
85        pattern, with a new opcode that causes them to be skipped at execution
86        time.
87    
88    13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
89        to the way PCRE behaves:
90    
91        (a) A lone ] character is dis-allowed (Perl treats it as data).
92    
93        (b) A back reference to an unmatched subpattern matches an empty string
94            (Perl fails the current match path).
95    
96        (c) A data ] in a character class must be notated as \] because if the
97            first data character in a class is ], it defines an empty class. (In
98            Perl it is not possible to have an empty class.) The empty class []
99            never matches; it forces failure and is equivalent to (*FAIL) or (?!).
100            The negative empty class [^] matches any one character, independently
101            of the DOTALL setting.
102    
103    14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
104        non-existent subpattern following a character class starting with ']' and
105        containing () gave an internal compiling error instead of "reference to
106        non-existent subpattern". Fortunately, when the pattern did exist, the
107        compiled code was correct. (When scanning forwards to check for the
108        existencd of the subpattern, it was treating the data ']' as terminating
109        the class, so got the count wrong. When actually compiling, the reference
110        was subsequently set up correctly.)
111    
112    15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
113        it was being rejected as not supported by pcre_dfa_exec(), even though
114        other assertions are supported. I have made pcre_dfa_exec() support
115        (*FAIL).
116    
117    16. The implementation of 13c above involved the invention of a new opcode,
118        OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
119        cannot be changed at match time, I realized I could make a small
120        improvement to matching performance by compiling OP_ALLANY instead of
121        OP_ANY for "." when DOTALL was set, and then removing the runtime tests
122        on the OP_ANY path.
123    
124    17. Compiling pcretest on Windows with readline support failed without the
125        following two fixes: (1) Make the unistd.h include conditional on
126        HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
127    
128    18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
129        ncurses library to be included for pcretest when ReadLine support is
130        requested, but also to allow for it to be overridden. This patch came from
131        Daniel Bergström.
132    
133    19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
134        as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
135        any errors with the current Unicode tables. Thanks to Peter Kankowski for
136        spotting this.
137    
138    
139    Version 7.6 28-Jan-08
140    ---------------------
141    
142    1.  A character class containing a very large number of characters with
143        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
144        overflow.
145    
146    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
147        HAVE_LONG_LONG is not defined.
148    
149    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
150        bring them up to date and include new features. This patch includes:
151    
152        - Fixed PH's badly added libz and libbz2 support.
153        - Fixed a problem with static linking.
154        - Added pcredemo. [But later removed - see 7 below.]
155        - Fixed dftables problem and added an option.
156        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
157            HAVE_LONG_LONG.
158        - Added readline support for pcretest.
159        - Added an listing of the option settings after cmake has run.
160    
161    4.  A user submitted a patch to Makefile that makes it easy to create
162        "pcre.dll" under mingw when using Configure/Make. I added stuff to
163        Makefile.am that cause it to include this special target, without
164        affecting anything else. Note that the same mingw target plus all
165        the other distribution libraries and programs are now supported
166        when configuring with CMake (see 6 below) instead of with
167        Configure/Make.
168    
169    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
170        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
171        exported in the Windows port". It has not yet been confirmed that the patch
172        solves the problem, but it does no harm.
173    
174    6.  Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
175        NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
176        with CMake, and also correct the comment about stack recursion.
177    
178    7.  Remove the automatic building of pcredemo from the ./configure system and
179        from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
180        of a program that users should build themselves after PCRE is installed, so
181        building it automatically is not really right. What is more, it gave
182        trouble in some build environments.
183    
184    8.  Further tidies to CMakeLists.txt from Sheri and Christian.
185    
186    
187    Version 7.5 10-Jan-08
188    ---------------------
189    
190    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
191        values in parens when parsing an RE using the C++ wrapper."
192    
193    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
194        Characters greater than 255 were excluded from the class instead of being
195        included.
196    
197    3.  The same bug as (2) above applied to negated POSIX classes such as
198        [:^space:].
199    
200    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
201        defined or documented. It seems to have been a typo for PCRE_STATIC, so
202        I have changed it.
203    
204    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
205        first named subpattern) and a construct such as (?&a) would reference the
206        first named subpattern whose name started with "a" (in other words, the
207        length check was missing). Both these problems are fixed. "Subpattern name
208        expected" is now given for (?&) (a zero-length name), and this patch also
209        makes it give the same error for \k'' (previously it complained that that
210        was a reference to a non-existent subpattern).
211    
212    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
213        this is right because (?- can be followed by option settings as well as by
214        digits. I have, however, made the messages clearer.
215    
216    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
217        than the number used in the conditional) now cause a compile-time error.
218        This is actually not compatible with Perl, which accepts such patterns, but
219        treats the conditional as always being FALSE (as PCRE used to), but it
220        seems to me that giving a diagnostic is better.
221    
222    8.  Change "alphameric" to the more common word "alphanumeric" in comments
223        and messages.
224    
225    9.  Fix two occurrences of "backslash" in comments that should have been
226        "backspace".
227    
228    10. Remove two redundant lines of code that can never be obeyed (their function
229        was moved elsewhere).
230    
231    11. The program that makes PCRE's Unicode character property table had a bug
232        which caused it to generate incorrect table entries for sequences of
233        characters that have the same character type, but are in different scripts.
234        It amalgamated them into a single range, with the script of the first of
235        them. In other words, some characters were in the wrong script. There were
236        thirteen such cases, affecting characters in the following ranges:
237    
238          U+002b0 - U+002c1
239          U+0060c - U+0060d
240          U+0061e - U+00612
241          U+0064b - U+0065e
242          U+0074d - U+0076d
243          U+01800 - U+01805
244          U+01d00 - U+01d77
245          U+01d9b - U+01dbf
246          U+0200b - U+0200f
247          U+030fc - U+030fe
248          U+03260 - U+0327f
249          U+0fb46 - U+0fbb1
250          U+10450 - U+1049d
251    
252    12. The -o option (show only the matching part of a line) for pcregrep was not
253        compatible with GNU grep in that, if there was more than one match in a
254        line, it showed only the first of them. It now behaves in the same way as
255        GNU grep.
256    
257    13. If the -o and -v options were combined for pcregrep, it printed a blank
258        line for every non-matching line. GNU grep prints nothing, and pcregrep now
259        does the same. The return code can be used to tell if there were any
260        non-matching lines.
261    
262    14. Added --file-offsets and --line-offsets to pcregrep.
263    
264    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
265        infinitely looping recursion. The bug was that positive lookaheads were not
266        being skipped when checking for a possible empty match (negative lookaheads
267        and both kinds of lookbehind were skipped).
268    
269    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
270        inclusion of <windows.h> to before rather than after the definition of
271        INVALID_FILE_ATTRIBUTES (patch from David Byron).
272    
273    17. Specifying a possessive quantifier with a specific limit for a Unicode
274        character property caused pcre_compile() to compile bad code, which led at
275        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
276        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
277        caused the error; without that there was no problem.
278    
279    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
280    
281    19. Added --enable-pcretest-libreadline.
282    
283    20. In pcrecpp.cc, the variable 'count' was incremented twice in
284        RE::GlobalReplace(). As a result, the number of replacements returned was
285        double what it should be. I removed one of the increments, but Craig sent a
286        later patch that removed the other one (the right fix) and added unit tests
287        that check the return values (which was not done before).
288    
289    21. Several CMake things:
290    
291        (1) Arranged that, when cmake is used on Unix, the libraries end up with
292            the names libpcre and libpcreposix, not just pcre and pcreposix.
293    
294        (2) The above change means that pcretest and pcregrep are now correctly
295            linked with the newly-built libraries, not previously installed ones.
296    
297        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
298    
299    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
300        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
301        UTF-8 newline character). The key issue is that the pattern starts .*;
302        this means that the match must be either at the beginning, or after a
303        newline. The bug was in the code for advancing after a failed match and
304        checking that the new position followed a newline. It was not taking
305        account of UTF-8 characters correctly.
306    
307    23. PCRE was behaving differently from Perl in the way it recognized POSIX
308        character classes. PCRE was not treating the sequence [:...:] as a
309        character class unless the ... were all letters. Perl, however, seems to
310        allow any characters between [: and :], though of course it rejects as
311        unknown any "names" that contain non-letters, because all the known class
312        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
313        for example, whereas PCRE did not - it did not recognize a POSIX character
314        class. This seemed a bit dangerous, so the code has been changed to be
315        closer to Perl. The behaviour is not identical to Perl, because PCRE will
316        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
317        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
318        Perl does, and where it didn't before.
319    
320    24. Rewrite so as to remove the single use of %n from pcregrep because in some
321        Windows environments %n is disabled by default.
322    
323    
324    Version 7.4 21-Sep-07
325    ---------------------
326    
327    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
328        means that a class such as [\s] counted as "explicit reference to CR or
329        LF". That isn't really right - the whole point of the change was to try to
330        help when there was an actual mention of one of the two characters. So now
331        the change happens only if \r or \n (or a literal CR or LF) character is
332        encountered.
333    
334    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
335        of both had grown to the point where there were only 3 bits left.
336        Fortunately, there was spare space in the data structure, and so I have
337        moved the internal flags into a new 16-bit field to free up more option
338        bits.
339    
340    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
341        but did not set the internal JCHANGED flag - either of these is enough to
342        control the way the "get" function works - but the PCRE_INFO_JCHANGED
343        facility is supposed to tell if (?J) was ever used, so now (?J) at the
344        start sets both bits.
345    
346    4.  Added options (at build time, compile time, exec time) to change \R from
347        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
348    
349    5.  doc/pcresyntax.html was missing from the distribution.
350    
351    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
352        compatibility, even though it is no longer used.
353    
354    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
355        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
356        windows.h file is present (where different names are used). [This was
357        reversed later after testing - see 16 below.]
358    
359    8.  Changed all #include <config.h> to #include "config.h". There were also
360        some further <pcre.h> cases that I changed to "pcre.h".
361    
362    9.  When pcregrep was used with the --colour option, it missed the line ending
363        sequence off the lines that it output.
364    
365    10. It was pointed out to me that arrays of string pointers cause lots of
366        relocations when a shared library is dynamically loaded. A technique of
367        using a single long string with a table of offsets can drastically reduce
368        these. I have refactored PCRE in four places to do this. The result is
369        dramatic:
370    
371          Originally:                          290
372          After changing UCP table:            187
373          After changing error message table:   43
374          After changing table of "verbs"       36
375          After changing table of Posix names   22
376    
377        Thanks to the folks working on Gregex for glib for this insight.
378    
379    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
380        unicode-properties was also set.
381    
382    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
383    
384    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
385        checked only for CRLF.
386    
387    14. Added casts to pcretest.c to avoid compiler warnings.
388    
389    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
390    
391    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
392        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
393        entirely. This removes changes made in 7 above.
394    
395    17. The CMake files have been updated, and there is now more information about
396        building with CMake in the NON-UNIX-USE document.
397    
398    
399    Version 7.3 28-Aug-07
400    ---------------------
401    
402     1. In the rejigging of the build system that eventually resulted in 7.1, the
403        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
404        brackets there is not right, since it causes compilers to look for an
405        installed pcre.h, not the version that is in the source that is being
406        compiled (which of course may be different). I have changed it back to:
407    
408          #include "pcre.h"
409    
410        I have a vague recollection that the change was concerned with compiling in
411        different directories, but in the new build system, that is taken care of
412        by the VPATH setting the Makefile.
413    
414     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
415        when the subject happened to end in the byte 0x85 (e.g. if the last
416        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
417        characters but of course it shouldn't be taken as a newline when it is part
418        of another character. The bug was that, for an unlimited repeat of . in
419        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
420        characters when looking for a newline.
421    
422     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
423    
424     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
425        in debug output.
426    
427     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
428        long printing in the pcrecpp unittest when running under MinGW.
429    
430     6. ESC_K was left out of the EBCDIC table.
431    
432     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
433        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
434        limit also applies to "virtual nesting" when a pattern is recursive, and in
435        this case 1000 isn't so big. I have been able to remove this limit at the
436        expense of backing off one optimization in certain circumstances. Normally,
437        when pcre_exec() would call its internal match() function recursively and
438        immediately return the result unconditionally, it uses a "tail recursion"
439        feature to save stack. However, when a subpattern that can match an empty
440        string has an unlimited repetition quantifier, it no longer makes this
441        optimization. That gives it a stack frame in which to save the data for
442        checking that an empty string has been matched. Previously this was taken
443        from the 1000-entry workspace that had been reserved. So now there is no
444        explicit limit, but more stack is used.
445    
446     8. Applied Daniel's patches to solve problems with the import/export magic
447        syntax that is required for Windows, and which was going wrong for the
448        pcreposix and pcrecpp parts of the library. These were overlooked when this
449        problem was solved for the main library.
450    
451     9. There were some crude static tests to avoid integer overflow when computing
452        the size of patterns that contain repeated groups with explicit upper
453        limits. As the maximum quantifier is 65535, the maximum group length was
454        set at 30,000 so that the product of these two numbers did not overflow a
455        32-bit integer. However, it turns out that people want to use groups that
456        are longer than 30,000 bytes (though not repeat them that many times).
457        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
458        made it possible to implement the integer overflow checks in a much more
459        dynamic way, which I have now done. The artificial limitation on group
460        length has been removed - we now have only the limit on the total length of
461        the compiled pattern, which depends on the LINK_SIZE setting.
462    
463    10. Fixed a bug in the documentation for get/copy named substring when
464        duplicate names are permitted. If none of the named substrings are set, the
465        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
466        empty string.
467    
468    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
469        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
470        because the ] is interpreted as the first data character and the
471        terminating ] is not found. PCRE has been made compatible with Perl in this
472        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
473        cause memory overwriting.
474    
475    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
476        string has been matched (to stop an infinite loop). It was not recognizing
477        a conditional subpattern that could match an empty string if that
478        subpattern was within another subpattern. For example, it looped when
479        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
480        condition was not nested. This bug has been fixed.
481    
482    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
483        past the start of the subject in the presence of bytes with the top bit
484        set, for example "\x8aBCD".
485    
486    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
487        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
488    
489    14. Optimized (?!) to (*FAIL).
490    
491    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
492        This restricts code points to be within the range 0 to 0x10FFFF, excluding
493        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
494        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
495        does: it's just the validity check that is more restrictive.
496    
497    16. Inserted checks for integer overflows during escape sequence (backslash)
498        processing, and also fixed erroneous offset values for syntax errors during
499        backslash processing.
500    
501    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
502        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
503    
504    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
505        caused an overrun.
506    
507    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
508        something other than just ASCII characters) inside a group that had an
509        unlimited repeat caused a loop at compile time (while checking to see
510        whether the group could match an empty string).
511    
512    20. Debugging a pattern containing \p or \P could cause a crash. For example,
513        [\P{Any}] did so. (Error in the code for printing property names.)
514    
515    21. An orphan \E inside a character class could cause a crash.
516    
517    22. A repeated capturing bracket such as (A)? could cause a wild memory
518        reference during compilation.
519    
520    23. There are several functions in pcre_compile() that scan along a compiled
521        expression for various reasons (e.g. to see if it's fixed length for look
522        behind). There were bugs in these functions when a repeated \p or \P was
523        present in the pattern. These operators have additional parameters compared
524        with \d, etc, and these were not being taken into account when moving along
525        the compiled data. Specifically:
526    
527        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
528            length.
529    
530        (b) An item such as \pL+ within a repeated group could cause crashes or
531            loops.
532    
533        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
534            "reference to non-existent subpattern" error.
535    
536        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
537    
538    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
539        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
540    
541    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
542    
543    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
544        character were causing crashes (broken optimization).
545    
546    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
547        \p or \P) caused a compile-time loop.
548    
549    28. More problems have arisen in unanchored patterns when CRLF is a valid line
550        break. For example, the unstudied pattern [\r\n]A does not match the string
551        "\r\nA" because change 7.0/46 below moves the current point on by two
552        characters after failing to match at the start. However, the pattern \nA
553        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
554        the same is true. There doesn't seem any very clean way out of this, but
555        what I have chosen to do makes the common cases work: PCRE now takes note
556        of whether there can be an explicit match for \r or \n anywhere in the
557        pattern, and if so, 7.0/46 no longer applies. As part of this change,
558        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
559        pattern has explicit CR or LF references.
560    
561    29. Added (*CR) etc for changing newline setting at start of pattern.
562    
563    
564    Version 7.2 19-Jun-07
565    ---------------------
566    
567     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
568        which is apparently normally available under Windows.
569    
570     2. Re-jig the pcregrep tests with different newline settings in an attempt
571        to make them independent of the local environment's newline setting.
572    
573     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
574    
575     4. Some of the "internals" tests were previously cut out when the link size
576        was not 2, because the output contained actual offsets. The recent new
577        "Z" feature of pcretest means that these can be cut out, making the tests
578        usable with all link sizes.
579    
580     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
581        stack recursion. This gives a massive performance boost under BSD, but just
582        a small improvement under Linux. However, it saves one field in the frame
583        in all cases.
584    
585     6. Added more features from the forthcoming Perl 5.10:
586    
587        (a) (?-n) (where n is a string of digits) is a relative subroutine or
588            recursion call. It refers to the nth most recently opened parentheses.
589    
590        (b) (?+n) is also a relative subroutine call; it refers to the nth next
591            to be opened parentheses.
592    
593        (c) Conditions that refer to capturing parentheses can be specified
594            relatively, for example, (?(-2)... or (?(+3)...
595    
596        (d) \K resets the start of the current match so that everything before
597            is not part of it.
598    
599        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
600    
601        (f) \g{name} is another synonym - part of Perl 5.10's unification of
602            reference syntax.
603    
604        (g) (?| introduces a group in which the numbering of parentheses in each
605            alternative starts with the same number.
606    
607        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
608    
609     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
610        PCRE_INFO_JCHANGED.
611    
612     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
613        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
614        for detecting groups that can match an empty string.
615    
616     9. A pattern with a very large number of alternatives (more than several
617        hundred) was running out of internal workspace during the pre-compile
618        phase, where pcre_compile() figures out how much memory will be needed. A
619        bit of new cunning has reduced the workspace needed for groups with
620        alternatives. The 1000-alternative test pattern now uses 12 bytes of
621        workspace instead of running out of the 4096 that are available.
622    
623    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
624    
625    11. Applied patch from Google to remove an optimization that didn't quite work.
626        The report of the bug said:
627    
628          pcrecpp::RE("a*").FullMatch("aaa") matches, while
629          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
630          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
631    
632    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
633        it matched the wrong number of bytes.
634    
635    
636    Version 7.1 24-Apr-07
637    ---------------------
638    
639     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
640        that is more "standard", making use of automake and other Autotools. There
641        is some re-arrangement of the files and adjustment of comments consequent
642        on this.
643    
644     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
645        for recursive directory scanning broke on some systems because the files
646        are not scanned in any specific order and on different systems the order
647        was different. A call to "sort" has been inserted into RunGrepTest for the
648        approprate test as a short-term fix. In the longer term there may be an
649        alternative.
650    
651     3. I had an email from Eric Raymond about problems translating some of PCRE's
652        man pages to HTML (despite the fact that I distribute HTML pages, some
653        people do their own conversions for various reasons). The problems
654        concerned the use of low-level troff macros .br and .in. I have therefore
655        removed all such uses from the man pages (some were redundant, some could
656        be replaced by .nf/.fi pairs). The 132html script that I use to generate
657        HTML has been updated to handle .nf/.fi and to complain if it encounters
658        .br or .in.
659    
660     4. Updated comments in configure.ac that get placed in config.h.in and also
661        arranged for config.h to be included in the distribution, with the name
662        config.h.generic, for the benefit of those who have to compile without
663        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
664    
665     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
666        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
667        makevp.bat for the current PCRE, using the additional files
668        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
669    
670     6. A Windows user reported a minor discrepancy with test 2, which turned out
671        to be caused by a trailing space on an input line that had got lost in his
672        copy. The trailing space was an accident, so I've just removed it.
673    
674     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
675        that is needed.
676    
677     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
678        as "const" (a) because they are and (b) because it helps the PHP
679        maintainers who have recently made a script to detect big data structures
680        in the php code that should be moved to the .rodata section. I remembered
681        to update Builducptable as well, so it won't revert if ucptable.h is ever
682        re-created.
683    
684     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
685        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
686        order to be able to cut out the UTF-8 tables in the latter when UTF-8
687        support is not required. This saves 1.5-2K of code, which is important in
688        some applications.
689    
690        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
691        so as not to refer to the tables, even though these functions will never be
692        called when UTF-8 support is disabled. Otherwise there are problems with a
693        shared library.
694    
695    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
696    
697        (a) It was defining its arguments as char * instead of void *.
698    
699        (b) It was assuming that all moves were upwards in memory; this was true
700            a long time ago when I wrote it, but is no longer the case.
701    
702        The emulated memove() is provided for those environments that have neither
703        memmove() nor bcopy(). I didn't think anyone used it these days, but that
704        is clearly not the case, as these two bugs were recently reported.
705    
706    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
707        and Detrail to create the HTML documentation, the .txt form of the man
708        pages, and it removes trailing spaces from listed files. It also creates
709        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
710        case, it wraps all the #defines with #ifndefs. This script should be run
711        before "make dist".
712    
713    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
714        with Unicode property support.
715    
716        (a) For a maximizing quantifier, if the two different cases of the
717            character were of different lengths in their UTF-8 codings (there are
718            some cases like this - I found 11), and the matching function had to
719            back up over a mixture of the two cases, it incorrectly assumed they
720            were both the same length.
721    
722        (b) When PCRE was configured to use the heap rather than the stack for
723            recursion during matching, it was not correctly preserving the data for
724            the other case of a UTF-8 character when checking ahead for a match
725            while processing a minimizing repeat. If the check also involved
726            matching a wide character, but failed, corruption could cause an
727            erroneous result when trying to check for a repeat of the original
728            character.
729    
730    13. Some tidying changes to the testing mechanism:
731    
732        (a) The RunTest script now detects the internal link size and whether there
733            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
734            values substituted by "configure". (The RunGrepTest script already did
735            this for UTF-8.) The configure.ac script no longer substitutes the
736            relevant variables.
737    
738        (b) The debugging options /B and /D in pcretest show the compiled bytecode
739            with length and offset values. This means that the output is different
740            for different internal link sizes. Test 2 is skipped for link sizes
741            other than 2 because of this, bypassing the problem. Unfortunately,
742            there was also a test in test 3 (the locale tests) that used /B and
743            failed for link sizes other than 2. Rather than cut the whole test out,
744            I have added a new /Z option to pcretest that replaces the length and
745            offset values with spaces. This is now used to make test 3 independent
746            of link size. (Test 2 will be tidied up later.)
747    
748    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
749        segmentation fault instead of returning the appropriate error message.
750    
751    15. In multiline mode when the newline sequence was set to "any", the pattern
752        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
753        This doesn't seem right; it now treats the CRLF combination as the line
754        ending, and so does not match in that case. It's only a pattern such as ^$
755        that would hit this one: something like ^ABC$ would have failed after \r
756        and then tried again after \r\n.
757    
758    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
759        in an attempt to make files that differ only in their line terminators
760        compare equal. This works on Linux.
761    
762    17. Under certain error circumstances pcregrep might try to free random memory
763        as it exited. This is now fixed, thanks to valgrind.
764    
765    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
766        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
767        was because its rules for how to advance for /g after matching an empty
768        string at the end of a line did not allow for this case. They now check for
769        it specially.
770    
771    20. pcretest is supposed to handle patterns and data of any length, by
772        extending its buffers when necessary. It was getting this wrong when the
773        buffer for a data line had to be extended.
774    
775    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
776        CRLF as a newline sequence.
777    
778    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
779        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
780        I have nevertheless tidied it up.
781    
782    23. Added some casts to kill warnings from HP-UX ia64 compiler.
783    
784    24. Added a man page for pcre-config.
785    
786    
787    Version 7.0 19-Dec-06
788    ---------------------
789    
790     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
791        moving to gcc 4.1.1.
792    
793     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
794        sys/time.h, which is documented as needed for this function. It doesn't
795        seem to matter on Linux, but it showed up on some releases of OS X.
796    
797     3. It seems that there are systems where bytes whose values are greater than
798        127 match isprint() in the "C" locale. The "C" locale should be the
799        default when a C program starts up. In most systems, only ASCII printing
800        characters match isprint(). This difference caused the output from pcretest
801        to vary, making some of the tests fail. I have changed pcretest so that:
802    
803        (a) When it is outputting text in the compiled version of a pattern, bytes
804            other than 32-126 are always shown as hex escapes.
805    
806        (b) When it is outputting text that is a matched part of a subject string,
807            it does the same, unless a different locale has been set for the match
808            (using the /L modifier). In this case, it uses isprint() to decide.
809    
810     4. Fixed a major bug that caused incorrect computation of the amount of memory
811        required for a compiled pattern when options that changed within the
812        pattern affected the logic of the preliminary scan that determines the
813        length. The relevant options are -x, and -i in UTF-8 mode. The result was
814        that the computed length was too small. The symptoms of this bug were
815        either the PCRE error "internal error: code overflow" from pcre_compile(),
816        or a glibc crash with a message such as "pcretest: free(): invalid next
817        size (fast)". Examples of patterns that provoked this bug (shown in
818        pcretest format) are:
819    
820          /(?-x: )/x
821          /(?x)(?-x: \s*#\s*)/
822          /((?i)[\x{c0}])/8
823          /(?i:[\x{c0}])/8
824    
825        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
826        is now done differently.
827    
828     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
829        wrapper classes; (b) implement a new function in the C++ scanner that is
830        more efficient than the old way of doing things because it avoids levels of
831        recursion in the regex matching; (c) add a paragraph to the documentation
832        for the FullMatch() function.
833    
834     6. The escape sequence \n was being treated as whatever was defined as
835        "newline". Not only was this contrary to the documentation, which states
836        that \n is character 10 (hex 0A), but it also went horribly wrong when
837        "newline" was defined as CRLF. This has been fixed.
838    
839     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
840        was being set to -1 for the "end of line" case (supposedly a value that no
841        character can have). Though this value is never used (the check for end of
842        line is "zero bytes in current character"), it caused compiler complaints.
843        I've changed it to 0xffffffff.
844    
845     8. In pcre_version.c, the version string was being built by a sequence of
846        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
847        string (as it is for production releases) called a macro with an empty
848        argument. The C standard says the result of this is undefined. The gcc
849        compiler treats it as an empty string (which was what was wanted) but it is
850        reported that Visual C gives an error. The source has been hacked around to
851        avoid this problem.
852    
853     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
854        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
855        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
856        of them did).
857    
858    10. Originally, pcretest opened its input and output without "b"; then I was
859        told that "b" was needed in some environments, so it was added for release
860        5.0 to both the input and output. (It makes no difference on Unix-like
861        systems.) Later I was told that it is wrong for the input on Windows. I've
862        now abstracted the modes into two macros, to make it easier to fiddle with
863        them, and removed "b" from the input mode under Windows.
864    
865    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
866    
867    12. Added -help and --help to pcretest as an official way of being reminded
868        of the options.
869    
870    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
871        and pcrecpp.cc because they annoy compilers at high warning levels.
872    
873    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
874    
875    15. Fixed an occurrence of == in configure.ac that should have been = (shell
876        scripts are not C programs :-) and which was not noticed because it works
877        on Linux.
878    
879    16. pcretest is supposed to handle any length of pattern and data line (as one
880        line or as a continued sequence of lines) by extending its input buffer if
881        necessary. This feature was broken for very long pattern lines, leading to
882        a string of junk being passed to pcre_compile() if the pattern was longer
883        than about 50K.
884    
885    17. I have done a major re-factoring of the way pcre_compile() computes the
886        amount of memory needed for a compiled pattern. Previously, there was code
887        that made a preliminary scan of the pattern in order to do this. That was
888        OK when PCRE was new, but as the facilities have expanded, it has become
889        harder and harder to keep it in step with the real compile phase, and there
890        have been a number of bugs (see for example, 4 above). I have now found a
891        cunning way of running the real compile function in a "fake" mode that
892        enables it to compute how much memory it would need, while actually only
893        ever using a few hundred bytes of working memory and without too many
894        tests of the mode. This should make future maintenance and development
895        easier. A side effect of this work is that the limit of 200 on the nesting
896        depth of parentheses has been removed (though this was never a serious
897        limitation, I suspect). However, there is a downside: pcre_compile() now
898        runs more slowly than before (30% or more, depending on the pattern). I
899        hope this isn't a big issue. There is no effect on runtime performance.
900    
901    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
902        newline (only possible for the last line of a file) and it was a
903        pattern that set a locale (followed by /Lsomething), pcretest crashed.
904    
905    19. Added additional timing features to pcretest. (1) The -tm option now times
906        matching only, not compiling. (2) Both -t and -tm can be followed, as a
907        separate command line item, by a number that specifies the number of
908        repeats to use when timing. The default is 50000; this gives better
909        precision, but takes uncomfortably long for very large patterns.
910    
911    20. Extended pcre_study() to be more clever in cases where a branch of a
912        subpattern has no definite first character. For example, (a*|b*)[cd] would
913        previously give no result from pcre_study(). Now it recognizes that the
914        first character must be a, b, c, or d.
915    
916    21. There was an incorrect error "recursive call could loop indefinitely" if
917        a subpattern (or the entire pattern) that was being tested for matching an
918        empty string contained only one non-empty item after a nested subpattern.
919        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
920        incorrectly, because the \d was being skipped in the check.
921    
922    22. The pcretest program now has a new pattern option /B and a command line
923        option -b, which is equivalent to adding /B to every pattern. This causes
924        it to show the compiled bytecode, without the additional information that
925        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
926        is the same as /B/I).
927    
928    23. A new optimization is now able automatically to treat some sequences such
929        as a*b as a*+b. More specifically, if something simple (such as a character
930        or a simple class like \d) has an unlimited quantifier, and is followed by
931        something that cannot possibly match the quantified thing, the quantifier
932        is automatically "possessified".
933    
934    24. A recursive reference to a subpattern whose number was greater than 39
935        went wrong under certain circumstances in UTF-8 mode. This bug could also
936        have affected the operation of pcre_study().
937    
938    25. Realized that a little bit of performance could be had by replacing
939        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
940    
941    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
942    
943    27. Possessive quantifiers such as a++ were previously implemented by turning
944        them into atomic groups such as ($>a+). Now they have their own opcodes,
945        which improves performance. This includes the automatically created ones
946        from 23 above.
947    
948    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
949        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
950        the first matched character to be a colon. This applied both to named and
951        numbered groups.
952    
953    29. The ucpinternal.h header file was missing its idempotency #ifdef.
954    
955    30. I was sent a "project" file called libpcre.a.dev which I understand makes
956        building PCRE on Windows easier, so I have included it in the distribution.
957    
958    31. There is now a check in pcretest against a ridiculously large number being
959        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
960        loop, the loop is abandoned.
961    
962    32. Forward references to subpatterns in conditions such as (?(2)...) where
963        subpattern 2 is defined later cause pcre_compile() to search forwards in
964        the pattern for the relevant set of parentheses. This search went wrong
965        when there were unescaped parentheses in a character class, parentheses
966        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
967    
968    33. "Subroutine" calls and backreferences were previously restricted to
969        referencing subpatterns earlier in the regex. This restriction has now
970        been removed.
971    
972    34. Added a number of extra features that are going to be in Perl 5.10. On the
973        whole, these are just syntactic alternatives for features that PCRE had
974        previously implemented using the Python syntax or my own invention. The
975        other formats are all retained for compatibility.
976    
977        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
978            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
979            also .NET compatible.
980    
981        (b) A recursion or subroutine call to a named group can now be defined as
982            (?&name) as well as (?P>name).
983    
984        (c) A backreference to a named group can now be defined as \k<name> or
985            \k'name' as well as (?P=name). The new forms, as well as being in Perl
986            5.10, are also .NET compatible.
987    
988        (d) A conditional reference to a named group can now use the syntax
989            (?(<name>) or (?('name') as well as (?(name).
990    
991        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
992            groups (named and numbered) that are never evaluated inline, but can be
993            called as "subroutines" from elsewhere. In effect, the DEFINE condition
994            is always false. There may be only one alternative in such a group.
995    
996        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
997            as the simple (?(R). The condition is true only if the most recent
998            recursion is that of the given number or name. It does not search out
999            through the entire recursion stack.
1000    
1001        (g) The escape \gN or \g{N} has been added, where N is a positive or
1002            negative number, specifying an absolute or relative reference.
1003    
1004    35. Tidied to get rid of some further signed/unsigned compiler warnings and
1005        some "unreachable code" warnings.
1006    
1007    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1008        things, this adds five new scripts.
1009    
1010    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1011        There were also incompatibilities regarding the handling of \Q..\E inside
1012        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1013        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1014    
1015    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1016        matches an empty string, and forcibly breaks the loop. There were bugs in
1017        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
1018        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
1019        separate and independent bugs (that affected different cases) have been
1020        fixed.
1021    
1022    39. Refactored the code to abolish the use of different opcodes for small
1023        capturing bracket numbers. This is a tidy that I avoided doing when I
1024        removed the limit on the number of capturing brackets for 3.5 back in 2001.
1025        The new approach is not only tidier, it makes it possible to reduce the
1026        memory needed to fix the previous bug (38).
1027    
1028    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1029        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1030        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1031        mode.
1032    
1033    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1034        report.
1035    
1036    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1037        copy construction and assignment in the C++ wrapper.
1038    
1039    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1040        couple of bugs that could have given wrong results in the "--newline=crlf"
1041        case.
1042    
1043    44. Added a number of casts and did some reorganization of signed/unsigned int
1044        variables following suggestions from Dair Grant. Also renamed the variable
1045        "this" as "item" because it is a C++ keyword.
1046    
1047    45. Arranged for dftables to add
1048    
1049          #include "pcre_internal.h"
1050    
1051        to pcre_chartables.c because without it, gcc 4.x may remove the array
1052        definition from the final binary if PCRE is built into a static library and
1053        dead code stripping is activated.
1054    
1055    46. For an unanchored pattern, if a match attempt fails at the start of a
1056        newline sequence, and the newline setting is CRLF or ANY, and the next two
1057        characters are CRLF, advance by two characters instead of one.
1058    
1059    
1060    Version 6.7 04-Jul-06
1061    ---------------------
1062    
1063     1. In order to handle tests when input lines are enormously long, pcretest has
1064        been re-factored so that it automatically extends its buffers when
1065        necessary. The code is crude, but this _is_ just a test program. The
1066        default size has been increased from 32K to 50K.
1067    
1068     2. The code in pcre_study() was using the value of the re argument before
1069        testing it for NULL. (Of course, in any sensible call of the function, it
1070        won't be NULL.)
1071    
1072     3. The memmove() emulation function in pcre_internal.h, which is used on
1073        systems that lack both memmove() and bcopy() - that is, hardly ever -
1074        was missing a "static" storage class specifier.
1075    
1076     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1077        containing an extended class (one that cannot be represented by a bitmap
1078        because it contains high-valued characters or Unicode property items, e.g.
1079        [\pZ]). Almost always one would set UTF-8 mode when processing such a
1080        pattern, but PCRE should not loop if you do not (it no longer does).
1081        [Detail: two cases were found: (a) a repeated subpattern containing an
1082        extended class; (b) a recursive reference to a subpattern that followed a
1083        previous extended class. It wasn't skipping over the extended class
1084        correctly when UTF-8 mode was not set.]
1085    
1086     5. A negated single-character class was not being recognized as fixed-length
1087        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1088        compile error "lookbehind assertion is not fixed length".
1089    
1090     6. The RunPerlTest auxiliary script was showing an unexpected difference
1091        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1092        write a Perl script that can interpret lines of an input file either as
1093        byte characters or as UTF-8, which is what "perltest" was being required to
1094        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1095        can't do is switch easily at run time between having the "use utf8;" pragma
1096        or not. In the end, I fudged it by using the RunPerlTest script to insert
1097        "use utf8;" explicitly for the UTF-8 tests.
1098    
1099     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1100        the end of the subject string, contrary to the documentation and to what
1101        Perl does. This was true of both matching functions. Now it matches only at
1102        the start of the subject and immediately after *internal* newlines.
1103    
1104     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1105        a pointer to an int instead of a pointer to an unsigned long int. This
1106        caused problems on 64-bit systems.
1107    
1108     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1109        instance of the 'standard' template library not being so standard".
1110    
1111    10. There was no check on the number of named subpatterns nor the maximum
1112        length of a subpattern name. The product of these values is used to compute
1113        the size of the memory block for a compiled pattern. By supplying a very
1114        long subpattern name and a large number of named subpatterns, the size
1115        computation could be caused to overflow. This is now prevented by limiting
1116        the length of names to 32 characters, and the number of named subpatterns
1117        to 10,000.
1118    
1119    11. Subpatterns that are repeated with specific counts have to be replicated in
1120        the compiled pattern. The size of memory for this was computed from the
1121        length of the subpattern and the repeat count. The latter is limited to
1122        65535, but there was no limit on the former, meaning that integer overflow
1123        could in principle occur. The compiled length of a repeated subpattern is
1124        now limited to 30,000 bytes in order to prevent this.
1125    
1126    12. Added the optional facility to have named substrings with the same name.
1127    
1128    13. Added the ability to use a named substring as a condition, using the
1129        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1130        are numbers (not recommended). Forward references are permitted.
1131    
1132    14. Added forward references in named backreferences (if you see what I mean).
1133    
1134    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1135        pattern could run off the end of the subject. For example, the pattern
1136        "(?s)(.{1,5})"8 did this with the subject "ab".
1137    
1138    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1139        PCRE_CASELESS was set when matching characters that were quantified with ?
1140        or *.
1141    
1142    17. A character class other than a single negated character that had a minimum
1143        but no maximum quantifier - for example [ab]{6,} - was not handled
1144        correctly by pce_dfa_exec(). It would match only one character.
1145    
1146    18. A valid (though odd) pattern that looked like a POSIX character
1147        class but used an invalid character after [ (for example [[,abc,]]) caused
1148        pcre_compile() to give the error "Failed: internal error: code overflow" or
1149        in some cases to crash with a glibc free() error. This could even happen if
1150        the pattern terminated after [[ but there just happened to be a sequence of
1151        letters, a binary zero, and a closing ] in the memory that followed.
1152    
1153    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1154        over the years. Originally (before any Unicode support), just the bottom 8
1155        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1156        output from "man perlunicode" includes this:
1157    
1158          The regular expression compiler produces polymorphic opcodes.  That
1159          is, the pattern adapts to the data and automatically switches to
1160          the Unicode character scheme when presented with Unicode data--or
1161          instead uses a traditional byte scheme when presented with byte
1162          data.
1163    
1164        Sadly, a wide octal escape does not cause a switch, and in a string with
1165        no other multibyte characters, these octal escapes are treated as before.
1166        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
1167        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1168        Unicode string.
1169    
1170        I have not perpetrated such confusion in PCRE. Up till now, it took just
1171        the bottom 8 bits, as in old Perl. I have now made octal escapes with
1172        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1173        translate to the appropriate multibyte character.
1174    
1175    29. Applied some refactoring to reduce the number of warnings from Microsoft
1176        and Borland compilers. This has included removing the fudge introduced
1177        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1178        a warning about an unused variable.
1179    
1180    21. PCRE has not included VT (character 0x0b) in the set of whitespace
1181        characters since release 4.0, because Perl (from release 5.004) does not.
1182        [Or at least, is documented not to: some releases seem to be in conflict
1183        with the documentation.] However, when a pattern was studied with
1184        pcre_study() and all its branches started with \s, PCRE still included VT
1185        as a possible starting character. Of course, this did no harm; it just
1186        caused an unnecessary match attempt.
1187    
1188    22. Removed a now-redundant internal flag bit that recorded the fact that case
1189        dependency changed within the pattern. This was once needed for "required
1190        byte" processing, but is no longer used. This recovers a now-scarce options
1191        bit. Also moved the least significant internal flag bit to the most-
1192        significant bit of the word, which was not previously used (hangover from
1193        the days when it was an int rather than a uint) to free up another bit for
1194        the future.
1195    
1196    23. Added support for CRLF line endings as well as CR and LF. As well as the
1197        default being selectable at build time, it can now be changed at runtime
1198        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1199        specify that it is scanning data with non-default line endings.
1200    
1201    24. Changed the definition of CXXLINK to make it agree with the definition of
1202        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1203    
1204    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1205        recursions. This makes a big different to stack usage for some patterns.
1206    
1207    26. If a subpattern containing a named recursion or subroutine reference such
1208        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1209        the space required for the compiled pattern went wrong and gave too small a
1210        value. Depending on the environment, this could lead to "Failed: internal
1211        error: code overflow at offset 49" or "glibc detected double free or
1212        corruption" errors.
1213    
1214    27. Applied patches from Google (a) to support the new newline modes and (b) to
1215        advance over multibyte UTF-8 characters in GlobalReplace.
1216    
1217    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1218        difference for some implementation of PCRE in some Windows version.
1219    
1220    29. Added some extra testing facilities to pcretest:
1221    
1222        \q<number>   in a data line sets the "match limit" value
1223        \Q<number>   in a data line sets the "match recursion limt" value
1224        -S <number>  sets the stack size, where <number> is in megabytes
1225    
1226        The -S option isn't available for Windows.
1227    
1228    
1229    Version 6.6 06-Feb-06
1230    ---------------------
1231    
1232     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1233        in pcreposix.h. I have copied the definition from pcre.h.
1234    
1235     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1236        because pcre.h is no longer a built file.
1237    
1238     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1239        not normally included in the compiled code.
1240    
1241    
1242    Version 6.5 01-Feb-06
1243    ---------------------
1244    
1245     1. When using the partial match feature with pcre_dfa_exec(), it was not
1246        anchoring the second and subsequent partial matches at the new starting
1247        point. This could lead to incorrect results. For example, with the pattern
1248        /1234/, partially matching against "123" and then "a4" gave a match.
1249    
1250     2. Changes to pcregrep:
1251    
1252        (a) All non-match returns from pcre_exec() were being treated as failures
1253            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1254            error message is output. Some extra information is given for the
1255            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1256            probably the only errors that are likely to be caused by users (by
1257            specifying a regex that has nested indefinite repeats, for instance).
1258            If there are more than 20 of these errors, pcregrep is abandoned.
1259    
1260        (b) A binary zero was treated as data while matching, but terminated the
1261            output line if it was written out. This has been fixed: binary zeroes
1262            are now no different to any other data bytes.
1263    
1264        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1265            used to set a locale for matching. The --locale=xxxx long option has
1266            been added (no short equivalent) to specify a locale explicitly on the
1267            pcregrep command, overriding the environment variables.
1268    
1269        (d) When -B was used with -n, some line numbers in the output were one less
1270            than they should have been.
1271    
1272        (e) Added the -o (--only-matching) option.
1273    
1274        (f) If -A or -C was used with -c (count only), some lines of context were
1275            accidentally printed for the final match.
1276    
1277        (g) Added the -H (--with-filename) option.
1278    
1279        (h) The combination of options -rh failed to suppress file names for files
1280            that were found from directory arguments.
1281    
1282        (i) Added the -D (--devices) and -d (--directories) options.
1283    
1284        (j) Added the -F (--fixed-strings) option.
1285    
1286        (k) Allow "-" to be used as a file name for -f as well as for a data file.
1287    
1288        (l) Added the --colo(u)r option.
1289    
1290        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1291            is not present by default.
1292    
1293     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1294        items such as (?R) or (?1), when the recursion could match a number of
1295        alternatives. If it matched one of the alternatives, but subsequently,
1296        outside the recursion, there was a failure, the code tried to back up into
1297        the recursion. However, because of the way PCRE is implemented, this is not
1298        possible, and the result was an incorrect result from the match.
1299    
1300        In order to prevent this happening, the specification of recursion has
1301        been changed so that all such subpatterns are automatically treated as
1302        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1303    
1304     4. I had overlooked the fact that, in some locales, there are characters for
1305        which isalpha() is true but neither isupper() nor islower() are true. In
1306        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1307        and ordfeminine) are like this. This affected the treatment of \w and \W
1308        when they appeared in character classes, but not when they appeared outside
1309        a character class. The bit map for "word" characters is now created
1310        separately from the results of isalnum() instead of just taking it from the
1311        upper, lower, and digit maps. (Plus the underscore character, of course.)
1312    
1313     5. The above bug also affected the handling of POSIX character classes such as
1314        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1315        permanent tables. Instead, the bit maps for such a class were previously
1316        created as the appropriate unions of the upper, lower, and digit bitmaps.
1317        Now they are created by subtraction from the [[:word:]] class, which has
1318        its own bitmap.
1319    
1320     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1321        It is created by subtracting the vertical space characters (\x09, \x0a,
1322        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1323        subtraction was done in the overall bitmap for a character class, meaning
1324        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1325        be recognized. This bug has been fixed.
1326    
1327     7. Patches from the folks at Google:
1328    
1329          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1330          real life, but is still worth protecting against".
1331    
1332          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1333          regular expressions".
1334    
1335          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1336          have it.
1337    
1338          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1339          "configure" and the latter not, in order to fix a problem somebody had
1340          with compiling the Arg class on HP-UX.
1341    
1342          (e) Improve the error-handling of the C++ wrapper a little bit.
1343    
1344          (f) New tests for checking recursion limiting.
1345    
1346     8. The pcre_memmove() function, which is used only if the environment does not
1347        have a standard memmove() function (and is therefore rarely compiled),
1348        contained two bugs: (a) use of int instead of size_t, and (b) it was not
1349        returning a result (though PCRE never actually uses the result).
1350    
1351     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1352        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1353        returned instead of calling malloc() with an overflowing number that would
1354        most likely cause subsequent chaos.
1355    
1356    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1357    
1358    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1359        with this option is matched, the nmatch and pmatch options of regexec() are
1360        ignored.
1361    
1362    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1363        provided in case anyone wants to the the POSIX interface with UTF-8
1364        strings.
1365    
1366    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1367        C++ linking (needed for some HP-UX environments).
1368    
1369    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1370        (unused parameter) and in the pcre_printint() function (omitted "default"
1371        switch label when the default is to do nothing).
1372    
1373    15. Added some code to make it possible, when PCRE is compiled as a C++
1374        library, to replace subject pointers for pcre_exec() with a smart pointer
1375        class, thus making it possible to process discontinuous strings.
1376    
1377    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1378        much the same function. They were added by different people who were trying
1379        to make PCRE easy to compile on non-Unix systems. It has been suggested
1380        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1381        for compiling on Windows systems. I have therefore replaced it with
1382        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1383        defaults to "extern" for C or "extern C" for C++, which works fine on
1384        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1385        SCOPE with something explicit in config.h. In addition:
1386    
1387        (a) pcreposix.h still had just "extern" instead of either of these macros;
1388            I have replaced it with PCRE_DATA_SCOPE.
1389    
1390        (b) Functions such as _pcre_xclass(), which are internal to the library,
1391            but external in the C sense, all had PCRE_EXPORT in their definitions.
1392            This is apparently wrong for the Windows case, so I have removed it.
1393            (It makes no difference on Unix-like systems.)
1394    
1395    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1396        of recursive calls to match(). This is different to MATCH_LIMIT because
1397        that limits the total number of calls to match(), not all of which increase
1398        the depth of recursion. Limiting the recursion depth limits the amount of
1399        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1400        when PCRE is compiled, and changed at run time. A patch from Google adds
1401        this functionality to the C++ interface.
1402    
1403    18. Changes to the handling of Unicode character properties:
1404    
1405        (a) Updated the table to Unicode 4.1.0.
1406    
1407        (b) Recognize characters that are not in the table as "Cn" (undefined).
1408    
1409        (c) I revised the way the table is implemented to a much improved format
1410            which includes recognition of ranges. It now supports the ranges that
1411            are defined in UnicodeData.txt, and it also amalgamates other
1412            characters into ranges. This has reduced the number of entries in the
1413            table from around 16,000 to around 3,000, thus reducing its size
1414            considerably. I realized I did not need to use a tree structure after
1415            all - a binary chop search is just as efficient. Having reduced the
1416            number of entries, I extended their size from 6 bytes to 8 bytes to
1417            allow for more data.
1418    
1419        (d) Added support for Unicode script names via properties such as \p{Han}.
1420    
1421    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1422        matching that character.
1423    
1424    20. When matching a repeated Unicode property with a minimum greater than zero,
1425        (for example \pL{2,}), PCRE could look past the end of the subject if it
1426        reached it while seeking the minimum number of characters. This could
1427        happen only if some of the characters were more than one byte long, because
1428        there is a check for at least the minimum number of bytes.
1429    
1430    21. Refactored the implementation of \p and \P so as to be more general, to
1431        allow for more different types of property in future. This has changed the
1432        compiled form incompatibly. Anybody with saved compiled patterns that use
1433        \p or \P will have to recompile them.
1434    
1435    22. Added "Any" and "L&" to the supported property types.
1436    
1437    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1438        but give a compile time error if the value is greater than 0xff.
1439    
1440    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1441        accidentally not being installed or uninstalled.
1442    
1443    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1444        made were to insert the current release number. This seemed silly, because
1445        it made things harder for people building PCRE on systems that don't run
1446        "configure". I have turned pcre.h into a distributed file, no longer built
1447        by "configure", with the version identification directly included. There is
1448        no longer a pcre.h.in file.
1449    
1450        However, this change necessitated a change to the pcre-config script as
1451        well. It is built from pcre-config.in, and one of the substitutions was the
1452        release number. I have updated configure.ac so that ./configure now finds
1453        the release number by grepping pcre.h.
1454    
1455    26. Added the ability to run the tests under valgrind.
1456    
1457    
1458    Version 6.4 05-Sep-05
1459    ---------------------
1460    
1461     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1462        "--" to be printed when multiple files were scanned, even when none of the
1463        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1464        consider it to be a bug, and have restored the previous behaviour.
1465    
1466     2. A couple of code tidies to get rid of compiler warnings.
1467    
1468     3. The pcretest program used to cheat by referring to symbols in the library
1469        whose names begin with _pcre_. These are internal symbols that are not
1470        really supposed to be visible externally, and in some environments it is
1471        possible to suppress them. The cheating is now confined to including
1472        certain files from the library's source, which is a bit cleaner.
1473    
1474     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1475        file's purpose clearer.
1476    
1477     5. Reorganized pcre_ucp_findchar().
1478    
1479    
1480    Version 6.3 15-Aug-05
1481    ---------------------
1482    
1483     1. The file libpcre.pc.in did not have general read permission in the tarball.
1484    
1485     2. There were some problems when building without C++ support:
1486    
1487        (a) If C++ support was not built, "make install" and "make test" still
1488            tried to test it.
1489    
1490        (b) There were problems when the value of CXX was explicitly set. Some
1491            changes have been made to try to fix these, and ...
1492    
1493        (c) --disable-cpp can now be used to explicitly disable C++ support.
1494    
1495        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1496            backslash in a target when C++ was disabled. This confuses some
1497            versions of "make", apparently. Using an intermediate variable solves
1498            this. (Same for CPP_LOBJ.)
1499    
1500     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1501        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1502        necessary on certain architectures.
1503    
1504     4. Added a setting of -export-symbols-regex to the link command to remove
1505        those symbols that are exported in the C sense, but actually are local
1506        within the library, and not documented. Their names all begin with
1507        "_pcre_". This is not a perfect job, because (a) we have to except some
1508        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1509        available (and never for static libraries). I have made a note to try to
1510        find a way round (a) in the future.
1511    
1512    
1513    Version 6.2 01-Aug-05
1514    ---------------------
1515    
1516     1. There was no test for integer overflow of quantifier values. A construction
1517        such as {1111111111111111} would give undefined results. What is worse, if
1518        a minimum quantifier for a parenthesized subpattern overflowed and became
1519        negative, the calculation of the memory size went wrong. This could have
1520        led to memory overwriting.
1521    
1522     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1523    
1524     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1525        operating environments where this matters.
1526    
1527     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1528        PCRE options from within the C++ wrapper.
1529    
1530     5. Named capturing subpatterns were not being correctly counted when a pattern
1531        was compiled. This caused two problems: (a) If there were more than 100
1532        such subpatterns, the calculation of the memory needed for the whole
1533        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1534        back references of the form \12, where the number was greater than 9, were
1535        not recognized as back references, even though there were sufficient
1536        previous subpatterns.
1537    
1538     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1539        versions of gcc, e.g. 2.95.4.
1540    
1541    
1542    Version 6.1 21-Jun-05
1543    ---------------------
1544    
1545     1. There was one reference to the variable "posix" in pcretest.c that was not
1546        surrounded by "#if !defined NOPOSIX".
1547    
1548     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1549        the cross-check on the old pcre_info() function, for the benefit of the
1550        cut-down version of PCRE that is currently imported into Exim.
1551    
1552     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1553        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1554        patterns that start (?i) but I don't think that matters. The use of (?i) is
1555        just an example; this all applies to the other options as well.
1556    
1557     4. Since libtool seems to echo the compile commands it is issuing, the output
1558        from "make" can be reduced a bit by putting "@" in front of each libtool
1559        compile command.
1560    
1561     5. Patch from the folks at Google for configure.in to be a bit more thorough
1562        in checking for a suitable C++ installation before trying to compile the
1563        C++ stuff. This should fix a reported problem when a compiler was present,
1564        but no suitable headers.
1565    
1566     6. The man pages all had just "PCRE" as their title. I have changed them to
1567        be the relevant file name. I have also arranged that these names are
1568        retained in the file doc/pcre.txt, which is a concatenation in text format
1569        of all the man pages except the little individual ones for each function.
1570    
1571     7. The NON-UNIX-USE file had not been updated for the different set of source
1572        files that come with release 6. I also added a few comments about the C++
1573        wrapper.
1574    
1575    
1576    Version 6.0 07-Jun-05
1577    ---------------------
1578    
1579     1. Some minor internal re-organization to help with my DFA experiments.
1580    
1581     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1582        didn't matter for the library itself when fully configured, but did matter
1583        when compiling without UCP support, or within Exim, where the ucp files are
1584        not imported.
1585    
1586     3. Refactoring of the library code to split up the various functions into
1587        different source modules. The addition of the new DFA matching code (see
1588        below) to a single monolithic source would have made it really too
1589        unwieldy, quite apart from causing all the code to be include in a
1590        statically linked application, when only some functions are used. This is
1591        relevant even without the DFA addition now that patterns can be compiled in
1592        one application and matched in another.
1593    
1594        The downside of splitting up is that there have to be some external
1595        functions and data tables that are used internally in different modules of
1596        the library but which are not part of the API. These have all had their
1597        names changed to start with "_pcre_" so that they are unlikely to clash
1598        with other external names.
1599    
1600     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1601        a different (DFA) algorithm. Although it is slower than the original
1602        function, it does have some advantages for certain types of matching
1603        problem.
1604    
1605     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1606        including restarting after a partial match.
1607    
1608     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1609        defined when compiling for Windows was sent to me. I have put it into the
1610        code, though I have no means of testing or verifying it.
1611    
1612     7. Added the pcre_refcount() auxiliary function.
1613    
1614     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1615        match before or at the first newline in the subject string. In pcretest,
1616        the /f option on a pattern can be used to set this.
1617    
1618     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1619        would behave wrongly. This has been present in PCRE since release 4.0.
1620    
1621    10. A number of changes to the pcregrep command:
1622    
1623        (a) Refactored how -x works; insert ^(...)$ instead of setting
1624            PCRE_ANCHORED and checking the length, in preparation for adding
1625            something similar for -w.
1626    
1627        (b) Added the -w (match as a word) option.
1628    
1629        (c) Refactored the way lines are read and buffered so as to have more
1630            than one at a time available.
1631    
1632        (d) Implemented a pcregrep test script.
1633    
1634        (e) Added the -M (multiline match) option. This allows patterns to match
1635            over several lines of the subject. The buffering ensures that at least
1636            8K, or the rest of the document (whichever is the shorter) is available
1637            for matching (and similarly the previous 8K for lookbehind assertions).
1638    
1639        (f) Changed the --help output so that it now says
1640    
1641              -w, --word-regex(p)
1642    
1643            instead of two lines, one with "regex" and the other with "regexp"
1644            because that confused at least one person since the short forms are the
1645            same. (This required a bit of code, as the output is generated
1646            automatically from a table. It wasn't just a text change.)
1647    
1648        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1649            option but starts with a hyphen. Could be a pattern or a path name
1650            starting with a hyphen, for instance.
1651    
1652        (h) "-" can be given as a file name to represent stdin.
1653    
1654        (i) When file names are being printed, "(standard input)" is used for
1655            the standard input, for compatibility with GNU grep. Previously
1656            "<stdin>" was used.
1657    
1658        (j) The option --label=xxx can be used to supply a name to be used for
1659            stdin when file names are being printed. There is no short form.
1660    
1661        (k) Re-factored the options decoding logic because we are going to add
1662            two more options that take data. Such options can now be given in four
1663            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1664    
1665        (l) Added the -A, -B, and -C options for requesting that lines of context
1666            around matches be printed.
1667    
1668        (m) Added the -L option to print the names of files that do not contain
1669            any matching lines, that is, the complement of -l.
1670    
1671        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1672            continue to scan other files.
1673    
1674        (o) The -s option was incorrectly implemented. For compatibility with other
1675            greps, it now suppresses the error message for a non-existent or non-
1676            accessible file (but not the return code). There is a new option called
1677            -q that suppresses the output of matching lines, which was what -s was
1678            previously doing.
1679    
1680        (p) Added --include and --exclude options to specify files for inclusion
1681            and exclusion when recursing.
1682    
1683    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1684        Hopefully, it now does.
1685    
1686    12. Missing cast in pcre_study().
1687    
1688    13. Added an "uninstall" target to the makefile.
1689    
1690    14. Replaced "extern" in the function prototypes in Makefile.in with
1691        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1692        world, but is set differently for Windows.
1693    
1694    15. Added a second compiling function called pcre_compile2(). The only
1695        difference is that it has an extra argument, which is a pointer to an
1696        integer error code. When there is a compile-time failure, this is set
1697        non-zero, in addition to the error test pointer being set to point to an
1698        error message. The new argument may be NULL if no error number is required
1699        (but then you may as well call pcre_compile(), which is now just a
1700        wrapper). This facility is provided because some applications need a
1701        numeric error indication, but it has also enabled me to tidy up the way
1702        compile-time errors are handled in the POSIX wrapper.
1703    
1704    16. Added VPATH=.libs to the makefile; this should help when building with one
1705        prefix path and installing with another. (Or so I'm told by someone who
1706        knows more about this stuff than I do.)
1707    
1708    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1709        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1710        match everything, including newlines. This is not POSIX-compatible, but
1711        somebody wanted the feature. From pcretest it can be activated by using
1712        both the P and the s flags.
1713    
1714    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1715    
1716    19. libpcre.pc was being incorrectly installed as executable.
1717    
1718    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1719        it now also looks for '\r' so that it will work unmodified on Windows.
1720    
1721    21. Added Google's contributed C++ wrapper to the distribution.
1722    
1723    22. Added some untidy missing memory free() calls in pcretest, to keep
1724        Electric Fence happy when testing.
1725    
1726    
1727    
1728    Version 5.0 13-Sep-04
1729    ---------------------
1730    
1731     1. Internal change: literal characters are no longer packed up into items
1732        containing multiple characters in a single byte-string. Each character
1733        is now matched using a separate opcode. However, there may be more than one
1734        byte in the character in UTF-8 mode.
1735    
1736     2. The pcre_callout_block structure has two new fields: pattern_position and
1737        next_item_length. These contain the offset in the pattern to the next match
1738        item, and its length, respectively.
1739    
1740     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1741        insertion of callouts before each pattern item. Added the /C option to
1742        pcretest to make use of this.
1743    
1744     4. On the advice of a Windows user, the lines
1745    
1746          #if defined(_WIN32) || defined(WIN32)
1747          _setmode( _fileno( stdout ), 0x8000 );
1748          #endif  /* defined(_WIN32) || defined(WIN32) */
1749    
1750        have been added to the source of pcretest. This apparently does useful
1751        magic in relation to line terminators.
1752    
1753     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1754        for the benefit of those environments where the "b" makes a difference.
1755    
1756     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1757        to know about it. I have put a hack into configure.in that adds in code
1758        to set GCC=yes if CC=icc. This seems to end up at a point in the
1759        generated configure script that is early enough to affect the setting of
1760        compiler options, which is what is needed, but I have no means of testing
1761        whether it really works. (The user who reported this had patched the
1762        generated configure script, which of course I cannot do.)
1763    
1764        LATER: After change 22 below (new libtool files), the configure script
1765        seems to know about icc (and also ecc). Therefore, I have commented out
1766        this hack in configure.in.
1767    
1768     7. Added support for pkg-config (2 patches were sent in).
1769    
1770     8. Negated POSIX character classes that used a combination of internal tables
1771        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1772        [[:^ascii]]. Typically, they would match almost any characters. The other
1773        POSIX classes were not broken in this way.
1774    
1775     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1776        to find the match, as PCRE was deluded into thinking that the match had to
1777        start at the start point or following a newline. The same bug applied to
1778        patterns with negative forward assertions or any backward assertions
1779        preceding ".*" at the start, unless the pattern required a fixed first
1780        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1781    
1782    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1783        starting at the last subject character, bytes beyond the end of the subject
1784        string were read.
1785    
1786    11. Renamed the variable "class" as "classbits" to make life easier for C++
1787        users. (Previously there was a macro definition, but it apparently wasn't
1788        enough.)
1789    
1790    12. Added the new field "tables" to the extra data so that tables can be passed
1791        in at exec time, or the internal tables can be re-selected. This allows
1792        a compiled regex to be saved and re-used at a later time by a different
1793        program that might have everything at different addresses.
1794    
1795    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1796        -R library as well as a -L library.
1797    
1798    14. The debugging options of pcretest (-d on the command line or D on a
1799        pattern) showed incorrect output for anything following an extended class
1800        that contained multibyte characters and which was followed by a quantifier.
1801    
1802    15. Added optional support for general category Unicode character properties
1803        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1804        support. It adds about 90K to the size of the library. The meanings of the
1805        inbuilt class escapes such as \d and \s have NOT been changed.
1806    
1807    16. Updated pcredemo.c to include calls to free() to release the memory for the
1808        compiled pattern.
1809    
1810    17. The generated file chartables.c was being created in the source directory
1811        instead of in the building directory. This caused the build to fail if the
1812        source directory was different from the building directory, and was
1813        read-only.
1814    
1815    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1816        file. No doubt somebody will tell me if they don't make sense... Also added
1817        Dan Mooney's comments about building on OpenVMS.
1818    
1819    19. Added support for partial matching via the PCRE_PARTIAL option for
1820        pcre_exec() and the \P data escape in pcretest.
1821    
1822    20. Extended pcretest with 3 new pattern features:
1823    
1824        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1825              write the compiled pattern to the file whose name is "rest-of-line".
1826              This is a straight binary dump of the data, with the saved pointer to
1827              the character tables forced to be NULL. The study data, if any, is
1828              written too. After writing, pcretest reads a new pattern.
1829    
1830        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1831              compiled pattern from the given file. There must not be any
1832              occurrences of "<" in the file name (pretty unlikely); if there are,
1833              pcretest will instead treat the initial "<" as a pattern delimiter.
1834              After reading in the pattern, pcretest goes on to read data lines as
1835              usual.
1836    
1837        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1838              and 16-bit fields in a compiled pattern, to simulate a pattern that
1839              was compiled on a host of opposite endianness.
1840    
1841    21. The pcre-exec() function can now cope with patterns that were compiled on
1842        hosts of opposite endianness, with this restriction:
1843    
1844          As for any compiled expression that is saved and used later, the tables
1845          pointer field cannot be preserved; the extra_data field in the arguments
1846          to pcre_exec() should be used to pass in a tables address if a value
1847          other than the default internal tables were used at compile time.
1848    
1849    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1850        now diagnosed as an error. Previously, most of the time, a negative number
1851        would have been treated as zero, but if in addition "ovector" was passed as
1852        NULL, a crash could occur.
1853    
1854    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1855        new versions from the libtool 1.5 distribution (the last one is a copy of
1856        a file called libtool.m4). This seems to have fixed the need to patch
1857        "configure" to support Darwin 1.3 (which I used to do). However, I still
1858        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1859        workstation).
1860    
1861    24. Changed the PCRE licence to be the more standard "BSD" licence.
1862    
1863    
1864    Version 4.5 01-Dec-03
1865    ---------------------
1866    
1867     1. There has been some re-arrangement of the code for the match() function so
1868        that it can be compiled in a version that does not call itself recursively.
1869        Instead, it keeps those local variables that need separate instances for
1870        each "recursion" in a frame on the heap, and gets/frees frames whenever it
1871        needs to "recurse". Keeping track of where control must go is done by means
1872        of setjmp/longjmp. The whole thing is implemented by a set of macros that
1873        hide most of the details from the main code, and operates only if
1874        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1875        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1876        operating.
1877    
1878        To make it easier for callers to provide specially tailored get/free
1879        functions for this usage, two new functions, pcre_stack_malloc, and
1880        pcre_stack_free, are used. They are always called in strict stacking order,
1881        and the size of block requested is always the same.
1882    
1883        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1884        PCRE has been compiled to use the stack or the heap for recursion. The
1885        -C option of pcretest uses this to show which version is compiled.
1886    
1887        A new data escape \S, is added to pcretest; it causes the amounts of store
1888        obtained and freed by both kinds of malloc/free at match time to be added
1889        to the output.
1890    
1891     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1892        what's available on my current Linux desktop machine.
1893    
1894     3. When matching a UTF-8 string, the test for a valid string at the start has
1895        been extended. If start_offset is not zero, PCRE now checks that it points
1896        to a byte that is the start of a UTF-8 character. If not, it returns
1897        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1898        this is necessary because there may be backward assertions in the pattern.
1899        When matching the same subject several times, it may save resources to use
1900        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1901    
1902     4. The code for checking the validity of UTF-8 strings has been tightened so
1903        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1904        containing "overlong sequences".
1905    
1906     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1907        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1908        should have been "&", but it just so happened that all the cases this let
1909        through by mistake were picked up later in the function.
1910    
1911     6. I had used a variable called "isblank" - this is a C99 function, causing
1912        some compilers to warn. To avoid this, I renamed it (as "blankclass").
1913    
1914     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1915        prompting; (b) run "./pcretest /dev/null" at the start of the test script
1916        so the version is shown; (c) stop "make test" echoing "./RunTest".
1917    
1918     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1919    
1920     9. The prototype for memmove() for systems that don't have it was using
1921        size_t, but the inclusion of the header that defines size_t was later. I've
1922        moved the #includes for the C headers earlier to avoid this.
1923    
1924    10. Added some adjustments to the code to make it easier to compiler on certain
1925        special systems:
1926    
1927          (a) Some "const" qualifiers were missing.
1928          (b) Added the macro EXPORT before all exported functions; by default this
1929              is defined to be empty.
1930          (c) Changed the dftables auxiliary program (that builds chartables.c) so
1931              that it reads its output file name as an argument instead of writing
1932              to the standard output and assuming this can be redirected.
1933    
1934    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1935        class containing characters with values greater than 255, PCRE compilation
1936        went into a loop.
1937    
1938    12. A recursive reference to a subpattern that was within another subpattern
1939        that had a minimum quantifier of zero caused PCRE to crash. For example,
1940        (x(y(?2))z)? provoked this bug with a subject that got as far as the
1941        recursion. If the recursively-called subpattern itself had a zero repeat,
1942        that was OK.
1943    
1944    13. In pcretest, the buffer for reading a data line was set at 30K, but the
1945        buffer into which it was copied (for escape processing) was still set at
1946        1024, so long lines caused crashes.
1947    
1948    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1949        "internal error: code overflow...". This applied to any character class
1950        that was followed by a possessive quantifier.
1951    
1952    15. Modified the Makefile to add libpcre.la as a prerequisite for
1953        libpcreposix.la because I was told this is needed for a parallel build to
1954        work.
1955    
1956    16. If a pattern that contained .* following optional items at the start was
1957        studied, the wrong optimizing data was generated, leading to matching
1958        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1959        matching string must start with a or b or c. The correct conclusion for
1960        this pattern is that a match can start with any character.
1961    
1962    
1963    Version 4.4 13-Aug-03
1964    ---------------------
1965    
1966     1. In UTF-8 mode, a character class containing characters with values between
1967        127 and 255 was not handled correctly if the compiled pattern was studied.
1968        In fixing this, I have also improved the studying algorithm for such
1969        classes (slightly).
1970    
1971     2. Three internal functions had redundant arguments passed to them. Removal
1972        might give a very teeny performance improvement.
1973    
1974     3. Documentation bug: the value of the capture_top field in a callout is *one
1975        more than* the number of the hightest numbered captured substring.
1976    
1977     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1978        in incorrectly linking with a previously installed version. They now link
1979        explicitly with libpcre.la.
1980    
1981     5. configure.in no longer needs to recognize Cygwin specially.
1982    
1983     6. A problem in pcre.in for Windows platforms is fixed.
1984    
1985     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1986        pcretest, it used to include the size of the study block as part of its
1987        output. Unfortunately, the structure contains a field that has a different
1988        size on different hardware architectures. This meant that the tests that
1989        showed this size failed. As the block is currently always of a fixed size,
1990        this information isn't actually particularly useful in pcretest output, so
1991        I have just removed it.
1992    
1993     8. Three pre-processor statements accidentally did not start in column 1.
1994        Sadly, there are *still* compilers around that complain, even though
1995        standard C has not required this for well over a decade. Sigh.
1996    
1997     9. In pcretest, the code for checking callouts passed small integers in the
1998        callout_data field, which is a void * field. However, some picky compilers
1999        complained about the casts involved for this on 64-bit systems. Now
2000        pcretest passes the address of the small integer instead, which should get
2001        rid of the warnings.
2002    
2003    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2004        both compile and run time, and gives an error if an invalid UTF-8 sequence
2005        is found. There is a option for disabling this check in cases where the
2006        string is known to be correct and/or the maximum performance is wanted.
2007    
2008    11. In response to a bug report, I changed one line in Makefile.in from
2009    
2010            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2011        to
2012            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2013    
2014        to look similar to other lines, but I have no way of telling whether this
2015        is the right thing to do, as I do not use Windows. No doubt I'll get told
2016        if it's wrong...
2017    
2018    
2019    Version 4.3 21-May-03
2020    ---------------------
2021    
2022    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2023       Makefile.
2024    
2025    2. Some refactoring to improve the quality of the code:
2026    
2027       (i)   The utf8_table... variables are now declared "const".
2028    
2029       (ii)  The code for \cx, which used the "case flipping" table to upper case
2030             lower case letters, now just substracts 32. This is ASCII-specific,
2031             but the whole concept of \cx is ASCII-specific, so it seems
2032             reasonable.
2033    
2034       (iii) PCRE was using its character types table to recognize decimal and
2035             hexadecimal digits in the pattern. This is silly, because it handles
2036             only 0-9, a-f, and A-F, but the character types table is locale-
2037             specific, which means strange things might happen. A private
2038             table is now used for this - though it costs 256 bytes, a table is
2039             much faster than multiple explicit tests. Of course, the standard
2040             character types table is still used for matching digits in subject
2041             strings against \d.
2042    
2043       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2044             ending in _t are). So I've renamed it as ESC_tee.
2045    
2046    3. The first argument for regexec() in the POSIX wrapper should have been
2047       defined as "const".
2048    
2049    4. Changed pcretest to use malloc() for its buffers so that they can be
2050       Electric Fenced for debugging.
2051    
2052    5. There were several places in the code where, in UTF-8 mode, PCRE would try
2053       to read one or more bytes before the start of the subject string. Often this
2054       had no effect on PCRE's behaviour, but in some circumstances it could
2055       provoke a segmentation fault.
2056    
2057    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2058       to try to read one or more bytes before the start of the subject string.
2059    
2060    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2061       UTF-8 support could misbehave in various ways if the subject string
2062       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2063       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2064       back over UTF-8 characters.)
2065    
2066    
2067    Version 4.2 14-Apr-03
2068    ---------------------
2069    
2070    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2071    
2072    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2073         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2074         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2075         [WIN_PREFIX]: new variable, "cyg" for Cygwin
2076         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2077           and BUILD_EXEEXT
2078         Note: automatic setting of the BUILD variables is not yet working
2079         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2080           compile-time but not at link-time
2081         [LINK]: use for linking executables only
2082         make different versions for Windows and non-Windows
2083         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2084           libraries
2085         [LINK_FOR_BUILD]: new variable
2086         [OBJEXT]: use throughout
2087         [EXEEXT]: use throughout
2088         <winshared>: new target
2089         <wininstall>: new target
2090         <dftables.o>: use native compiler
2091         <dftables>: use native linker
2092         <install>: handle Windows platform correctly
2093         <clean>: ditto
2094         <check>: ditto
2095         copy DLL to top builddir before testing
2096    
2097       As part of these changes, -no-undefined was removed again. This was reported
2098       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2099       in any case.
2100    
2101    3. Some tidies to get rid of compiler warnings:
2102    
2103       . In the match_data structure, match_limit was an unsigned long int, whereas
2104         match_call_count was an int. I've made them both unsigned long ints.
2105    
2106       . In pcretest the fact that a const uschar * doesn't automatically cast to
2107         a void * provoked a warning.
2108    
2109       . Turning on some more compiler warnings threw up some "shadow" variables
2110         and a few more missing casts.
2111    
2112    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2113       option, a class that contained a single character with a value between 128
2114       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2115    
2116    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2117       option, a class that contained several characters, but with at least one
2118       whose value was between 128 and 255 caused PCRE to crash.
2119    
2120    
2121    Version 4.1 12-Mar-03
2122    ---------------------
2123    
2124    1. Compiling with gcc -pedantic found a couple of places where casts were
2125    needed, and a string in dftables.c that was longer than standard compilers are
2126    required to support.
2127    
2128    2. Compiling with Sun's compiler found a few more places where the code could
2129    be tidied up in order to avoid warnings.
2130    
2131    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2132    first of these names is deprecated in the latest Autoconf in favour of the name
2133    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2134    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2135    analogy I have changed it to CFLAGS_FOR_BUILD.
2136    
2137    4. Added -no-undefined to the linking command in the Makefile, because this is
2138    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2139    linking step for the pcreposix library.
2140    
2141    5. PCRE was failing to diagnose the case of two named groups with the same
2142    name.
2143    
2144    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2145    literal character that is needed in the subject for a match, and scans along to
2146    ensure that it is present before embarking on the full matching process. This
2147    saves time in cases of nested unlimited repeats that are never going to match.
2148    Problem: the scan can take a lot of time if the subject is very long (e.g.
2149    megabytes), thus penalizing straightforward matches. It is now done only if the
2150    amount of subject to be scanned is less than 1000 bytes.
2151    
2152    7. A lesser problem with the same optimization is that it was recording the
2153    first character of an anchored pattern as "needed", thus provoking a search
2154    right along the subject, even when the first match of the pattern was going to
2155    fail. The "needed" character is now not set for anchored patterns, unless it
2156    follows something in the pattern that is of non-fixed length. Thus, it still
2157    fulfils its original purpose of finding quick non-matches in cases of nested
2158    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2159    
2160    
2161    Version 4.0 17-Feb-03
2162    ---------------------
2163    
2164    1. If a comment in an extended regex that started immediately after a meta-item
2165    extended to the end of string, PCRE compiled incorrect data. This could lead to
2166    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2167    
2168    2. Moved to autoconf 2.53 and libtool 1.4.2.
2169    
2170    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2171    the special perltest8 script is no longer needed - all the tests can be run
2172    from a single perltest script.
2173    
2174    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2175    by \s. It has now been removed in PCRE. This means it isn't recognized as
2176    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2177    class [:space:] *does* include VT, thereby creating a mess.
2178    
2179    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2180    space and tab.
2181    
2182    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2183    its new features into the main test script, reducing the number of scripts.
2184    
2185    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2186    were backward compatible, and made the (?i) apply to the whole pattern, as if
2187    /i were given. Now it behaves more logically, and applies the option setting
2188    only to what follows. PCRE has been changed to follow suit. However, if it
2189    finds options settings right at the start of the pattern, it extracts them into
2190    the global options, as before. Thus, they show up in the info data.
2191    
2192    8. Added support for the \Q...\E escape sequence. Characters in between are
2193    treated as literals. This is slightly different from Perl in that $ and @ are
2194    also handled as literals inside the quotes. In Perl, they will cause variable
2195    interpolation. Note the following examples:
2196    
2197        Pattern            PCRE matches      Perl matches
2198    
2199        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
2200        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
2201        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
2202    
2203    For compatibility with Perl, \Q...\E sequences are recognized inside character
2204    classes as well as outside them.
2205    
2206    9. Re-organized 3 code statements in pcretest to avoid "overflow in
2207    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2208    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2209    signed/unsigned warnings.
2210    
2211    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2212    option for pcretest, so I've replaced it by a simple function that does just
2213    that job.
2214    
2215    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2216    "pcregrep -".
2217    
2218    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2219    Java package. This provides some syntactic sugar for simple cases of what my
2220    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2221    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2222    item, you can use this simplified notation. Note that only makes sense with
2223    greedy quantifiers. Consequently, the use of the possessive quantifier forces
2224    greediness, whatever the setting of the PCRE_UNGREEDY option.
2225    
2226    13. A change of greediness default within a pattern was not taking effect at
2227    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2228    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2229    was abstracted outside.
2230    
2231    14. PCRE now supports the \G assertion. It is true when the current matching
2232    position is at the start point of the match. This differs from \A when the
2233    starting offset is non-zero. Used with the /g option of pcretest (or similar
2234    code), it works in the same way as it does for Perl's /g option. If all
2235    alternatives of a regex begin with \G, the expression is anchored to the start
2236    match position, and the "anchored" flag is set in the compiled expression.
2237    
2238    15. Some bugs concerning the handling of certain option changes within patterns
2239    have been fixed. These applied to options other than (?ims). For example,
2240    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2241    been the other way round. Some of this was related to change 7 above.
2242    
2243    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2244    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2245    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2246    POSIX classes only within a class (e.g. /[[:alpha:]]/).
2247    
2248    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2249    mode. Unlike ".", it always matches newline, whatever the setting of
2250    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2251    assertions. Perl allows it, but it doesn't (in general) work because it can't
2252    calculate the length of the lookbehind. At least, that's the case for Perl
2253    5.8.0 - I've been told they are going to document that it doesn't work in
2254    future.
2255    
2256    18. Added an error diagnosis for escapes that PCRE does not support: these are
2257    \L, \l, \N, \P, \p, \U, \u, and \X.
2258    
2259    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2260    reading past the end of the pattern in cases such as /[abcd/.
2261    
2262    20. PCRE was getting more memory than necessary for patterns with classes that
2263    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2264    
2265    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2266    compiling PCRE for use with Virtual Pascal.
2267    
2268    22. Small fix to the Makefile to make it work properly if the build is done
2269    outside the source tree.
2270    
2271    23. Added a new extension: a condition to go with recursion. If a conditional
2272    subpattern starts with (?(R) the "true" branch is used if recursion has
2273    happened, whereas the "false" branch is used only at the top level.
2274    
2275    24. When there was a very long string of literal characters (over 255 bytes
2276    without UTF support, over 250 bytes with UTF support), the computation of how
2277    much memory was required could be incorrect, leading to segfaults or other
2278    strange effects.
2279    
2280    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2281    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2282    there was a subsequent back reference to those brackets. This meant that, for
2283    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2284    possible to check for precisely this case. All we can do is abandon the
2285    optimization if .* occurs inside capturing brackets when there are any back
2286    references whatsoever. (See below for a better fix that came later.)
2287    
2288    26. The handling of the optimization for finding the first character of a
2289    non-anchored pattern, and for finding a character that is required later in the
2290    match were failing in some cases. This didn't break the matching; it just
2291    failed to optimize when it could. The way this is done has been re-implemented.
2292    
2293    27. Fixed typo in error message for invalid (?R item (it said "(?p").
2294    
2295    28. Added a new feature that provides some of the functionality that Perl
2296    provides with (?{...}). The facility is termed a "callout". The way it is done
2297    in PCRE is for the caller to provide an optional function, by setting
2298    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2299    global variable. By default it is unset, which disables all calling out. To get
2300    the function called, the regex must include (?C) at appropriate points. This
2301    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2302    This provides a means of identifying different callout points. When PCRE
2303    reaches such a point in the regex, if pcre_callout has been set, the external
2304    function is called. It is provided with data in a structure called
2305    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2306    matching continues; if it returns a non-zero value, the match at the current
2307    point fails. However, backtracking will occur if possible. [This was changed
2308    later and other features added - see item 49 below.]
2309    
2310    29. pcretest is upgraded to test the callout functionality. It provides a
2311    callout function that displays information. By default, it shows the start of
2312    the match and the current position in the text. There are some new data escapes
2313    to vary what happens:
2314    
2315        \C+         in addition, show current contents of captured substrings
2316        \C-         do not supply a callout function
2317        \C!n        return 1 when callout number n is reached
2318        \C!n!m      return 1 when callout number n is reached for the mth time
2319    
2320    30. If pcregrep was called with the -l option and just a single file name, it
2321    output "<stdin>" if a match was found, instead of the file name.
2322    
2323    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2324    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2325    pcre_exec(). This saves a malloc/free per call. The default value of
2326    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2327    when configuring.
2328    
2329    32. The default maximum size of a compiled pattern is 64K. There have been a
2330    few cases of people hitting this limit. The code now uses macros to handle the
2331    storing of links as offsets within the compiled pattern. It defaults to 2-byte
2332    links, but this can be changed to 3 or 4 bytes by --with-link-size when
2333    configuring. Tests 2 and 5 work only with 2-byte links because they output
2334    debugging information about compiled patterns.
2335    
2336    33. Internal code re-arrangements:
2337    
2338    (a) Moved the debugging function for printing out a compiled regex into
2339        its own source file (printint.c) and used #include to pull it into
2340        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2341        separate copies.
2342    
2343    (b) Defined the list of op-code names for debugging as a macro in
2344        internal.h so that it is next to the definition of the opcodes.
2345    
2346    (c) Defined a table of op-code lengths for simpler skipping along compiled
2347        code. This is again a macro in internal.h so that it is next to the
2348        definition of the opcodes.
2349    
2350    34. Added support for recursive calls to individual subpatterns, along the
2351    lines of Robin Houston's patch (but implemented somewhat differently).
2352    
2353    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2354    allow it to read and process whole directories in Win32. This code was
2355    contributed by Lionel Fourquaux; it has not been tested by me.
2356    
2357    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2358    used to name a group. Names consist of alphanumerics and underscores, and must
2359    be unique. Back references use the syntax (?P=name) and recursive calls use
2360    (?P>name) which is a PCRE extension to the Python extension. Groups still have
2361    numbers. The function pcre_fullinfo() can be used after compilation to extract
2362    a name/number map. There are three relevant calls:
2363    
2364      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
2365      PCRE_INFO_NAMECOUNT            yields the number of entries
2366      PCRE_INFO_NAMETABLE            yields a pointer to the map.
2367    
2368    The map is a vector of fixed-size entries. The size of each entry depends on
2369    the length of the longest name used. The first two bytes of each entry are the
2370    group number, most significant byte first. There follows the corresponding
2371    name, zero terminated. The names are in alphabetical order.
2372    
2373    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2374    case instead of 255. Making it the same both with and without UTF-8 support
2375    means that the same test output works with both.
2376    
2377    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2378    calling malloc() with a zero argument.
2379    
2380    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2381    optimization. I've improved things by keeping a bitmap of backreferences with
2382    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2383    fact referenced, the optimization can be applied. It is unlikely that a
2384    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2385    the match to follow \n) will appear inside brackets with a number greater than
2386    31, but if it does, any back reference > 31 suppresses the optimization.
2387    
2388    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2389    of disabling numbered capturing parentheses. Any opening parenthesis that is
2390    not followed by ? behaves as if it were followed by ?: but named parentheses
2391    can still be used for capturing (and they will acquire numbers in the usual
2392    way).
2393    
2394    41. Redesigned the return codes from the match() function into yes/no/error so
2395    that errors can be passed back from deep inside the nested calls. A malloc
2396    failure while inside a recursive subpattern call now causes the
2397    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2398    
2399    42. It is now possible to set a limit on the number of times the match()
2400    function is called in a call to pcre_exec(). This facility makes it possible to
2401    limit the amount of recursion and backtracking, though not in a directly
2402    obvious way, because the match() function is used in a number of different
2403    circumstances. The count starts from zero for each position in the subject
2404    string (for non-anchored patterns). The default limit is, for compatibility, a
2405    large number, namely 10 000 000. You can change this in two ways:
2406    
2407    (a) When configuring PCRE before making, you can use --with-match-limit=n
2408        to set a default value for the compiled library.
2409    
2410    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2411        a different value is set. See 45 below.
2412    
2413    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2414    
2415    43. Added a new function pcre_config(int, void *) to enable run-time extraction
2416    of things that can be changed at compile time. The first argument specifies
2417    what is wanted and the second points to where the information is to be placed.
2418    The current list of available information is:
2419    
2420      PCRE_CONFIG_UTF8
2421    
2422    The output is an integer that is set to one if UTF-8 support is available;
2423    otherwise it is set to zero.
2424    
2425      PCRE_CONFIG_NEWLINE
2426    
2427    The output is an integer that it set to the value of the code that is used for
2428    newline. It is either LF (10) or CR (13).
2429    
2430      PCRE_CONFIG_LINK_SIZE
2431    
2432    The output is an integer that contains the number of bytes used for internal
2433    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2434    
2435      PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2436    
2437    The output is an integer that contains the threshold above which the POSIX
2438    interface uses malloc() for output vectors. See item 31 above.
2439    
2440      PCRE_CONFIG_MATCH_LIMIT
2441    
2442    The output is an unsigned integer that contains the default limit of the number
2443    of match() calls in a pcre_exec() execution. See 42 above.
2444    
2445    44. pcretest has been upgraded by the addition of the -C option. This causes it
2446    to extract all the available output from the new pcre_config() function, and to
2447    output it. The program then exits immediately.
2448    
2449    45. A need has arisen to pass over additional data with calls to pcre_exec() in
2450    order to support additional features. One way would have been to define
2451    pcre_exec2() (for example) with extra arguments, but this would not have been
2452    extensible, and would also have required all calls to the original function to
2453    be mapped to the new one. Instead, I have chosen to extend the mechanism that
2454    is used for passing in "extra" data from pcre_study().
2455    
2456    The pcre_extra structure is now exposed and defined in pcre.h. It currently
2457    contains the following fields:
2458    
2459      flags         a bitmap indicating which of the following fields are set
2460      study_data    opaque data from pcre_study()
2461      match_limit   a way of specifying a limit on match() calls for a specific
2462                      call to pcre_exec()
2463      callout_data  data for callouts (see 49 below)
2464    
2465    The flag bits are also defined in pcre.h, and are
2466    
2467      PCRE_EXTRA_STUDY_DATA
2468      PCRE_EXTRA_MATCH_LIMIT
2469      PCRE_EXTRA_CALLOUT_DATA
2470    
2471    The pcre_study() function now returns one of these new pcre_extra blocks, with
2472    the actual study data pointed to by the study_data field, and the
2473    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2474    before. That is, this change is entirely upwards-compatible and requires no
2475    change to existing code.
2476    
2477    If you want to pass in additional data to pcre_exec(), you can either place it
2478    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2479    block.
2480    
2481    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2482    data string contains the escape sequence \M, pcretest calls pcre_exec() several
2483    times with different match limits, until it finds the minimum value needed for
2484    pcre_exec() to complete. The value is then output. This can be instructive; for
2485    most simple matches the number is quite small, but for pathological cases it
2486    gets very large very quickly.
2487    
2488    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2489    returns the size of the data block pointed to by the study_data field in a
2490    pcre_extra block, that is, the value that was passed as the argument to
2491    pcre_malloc() when PCRE was getting memory in which to place the information
2492    created by pcre_study(). The fourth argument should point to a size_t variable.
2493    pcretest has been extended so that this information is shown after a successful
2494    pcre_study() call when information about the compiled regex is being displayed.
2495    
2496    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2497    because what follows is always an absolute path. (Later: it turns out that this
2498    is more than cosmetic for MinGW, because it doesn't like empty path
2499    components.)
2500    
2501    49. Some changes have been made to the callout feature (see 28 above):
2502    
2503    (i)  A callout function now has three choices for what it returns:
2504    
2505           0  =>  success, carry on matching
2506         > 0  =>  failure at this point, but backtrack if possible
2507         < 0  =>  serious error, return this value from pcre_exec()
2508    
2509         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2510         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2511         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2512         use by callout functions. It will never be used by PCRE itself.
2513    
2514    (ii) The pcre_extra structure (see 45 above) has a void * field called
2515         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2516         pcre_callout_block structure has a field of the same name. The contents of
2517         the field passed in the pcre_extra structure are passed to the callout
2518         function in the corresponding field in the callout block. This makes it
2519         easier to use the same callout-containing regex from multiple threads. For
2520         testing, the pcretest program has a new data escape
2521    
2522           \C*n        pass the number n (may be negative) as callout_data
2523    
2524         If the callout function in pcretest receives a non-zero value as
2525         callout_data, it returns that value.
2526    
2527    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2528    there were some redundant $(CFLAGS) in commands that are now specified as
2529    $(LINK), which already includes $(CFLAGS).
2530    
2531    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2532    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2533    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2534    one-byte characters throughout. Note that case-insensitive matching applies
2535    only to characters whose values are less than 256. PCRE doesn't support the
2536    notion of cases for higher-valued characters.
2537    
2538    (i)   A character class whose characters are all within 0-255 is handled as
2539          a bit map, and the map is inverted for negative classes. Previously, a
2540          character > 255 always failed to match such a class; however it should
2541          match if the class was a negative one (e.g. [^ab]). This has been fixed.
2542    
2543    (ii)  A negated character class with a single character < 255 is coded as
2544          "not this character" (OP_NOT). This wasn't working properly when the test
2545          character was multibyte, either singly or repeated.
2546    
2547    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2548          mode, for example: \x{100}{2,3}.
2549    
2550    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2551          singly or repeated) now correctly test multibyte characters. However,
2552          PCRE doesn't recognize any characters with values greater than 255 as
2553          digits, spaces, or word characters. Such characters always match \D, \S,
2554          and \W, and never match \d, \s, or \w.
2555    
2556    (v)   Classes may now contain characters and character ranges with values
2557          greater than 255. For example: [ab\x{100}-\x{400}].
2558    
2559    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
2560          PCRE in UTF-8 mode.
2561    
2562    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2563    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2564    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2565    value.)
2566    
2567    53. The single man page has become too large. I have therefore split it up into
2568    a number of separate man pages. These also give rise to individual HTML pages;
2569    these are now put in a separate directory, and there is an index.html page that
2570    lists them all. Some hyperlinking between the pages has been installed.
2571    
2572    54. Added convenience functions for handling named capturing parentheses.
2573    
2574    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2575    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2576    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2577    are faulted.
2578    
2579    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2580    calling configure. These values are used when compiling the dftables.c program
2581    which is run to generate the source of the default character tables. They
2582    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2583    you will need to set these values.
2584    
2585    57. Updated the building process for Windows DLL, as provided by Fred Cox.
2586    
2587    
2588    Version 3.9 02-Jan-02
2589    ---------------------
2590    
2591    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2592    
2593    2. If --disable-static was given, the building process failed when trying to
2594    build pcretest and pcregrep. (For some reason it was using libtool to compile
2595    them, which is not right, as they aren't part of the library.)
2596    
2597    
2598    Version 3.8 18-Dec-01
2599    ---------------------
2600    
2601    1. The experimental UTF-8 code was completely screwed up. It was packing the
2602    bytes in the wrong order. How dumb can you get?
2603    
2604    
2605    Version 3.7 29-Oct-01
2606    ---------------------
2607    
2608    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2609    This caused pcretest, when used on the test data, to segfault. Unfortunately,
2610    this didn't happen under Solaris 8, where I normally test things.
2611    
2612    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2613    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2614    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2615    this fix an hour or so after the initial 3.7 release.)
2616    
2617    
2618    Version 3.6 23-Oct-01
2619    ---------------------
2620    
2621    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2622    offsets passed as NULL with zero offset count.
2623    
2624    2. The config.guess and config.sub files had not been updated when I moved to
2625    the latest autoconf.
2626    
2627    
2628    Version 3.5 15-Aug-01
2629    ---------------------
2630    
2631    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2632    had been forgotten.
2633    
2634    2. By using declared but undefined structures, we can avoid using "void"
2635    definitions in pcre.h while keeping the internal definitions of the structures
2636    private.
2637    
2638    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2639    user point of view, this means that both static and shared libraries are built
2640    by default, but this can be individually controlled. More of the work of
2641    handling this static/shared cases is now inside libtool instead of PCRE's make
2642    file.
2643    
2644    4. The pcretest utility is now installed along with pcregrep because it is
2645    useful for users (to test regexs) and by doing this, it automatically gets
2646    relinked by libtool. The documentation has been turned into a man page, so
2647    there are now .1, .txt, and .html versions in /doc.
2648    
2649    5. Upgrades to pcregrep:
2650       (i)   Added long-form option names like gnu grep.
2651       (ii)  Added --help to list all options with an explanatory phrase.
2652       (iii) Added -r, --recursive to recurse into sub-directories.
2653       (iv)  Added -f, --file to read patterns from a file.
2654    
2655    6. pcre_exec() was referring to its "code" argument before testing that
2656    argument for NULL (and giving an error if it was NULL).
2657    
2658    7. Upgraded Makefile.in to allow for compiling in a different directory from
2659    the source directory.
2660    
2661    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2662    options bits, the pointer it was passed was to an int instead of to an unsigned
2663    long int. This mattered only on 64-bit systems.
2664    
2665    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2666    generated) instead of pcre.in, which it its source. Also made the same change
2667    in several of the .c files.
2668    
2669    10. A new release of gcc defines printf() as a macro, which broke pcretest
2670    because it had an ifdef in the middle of a string argument for printf(). Fixed
2671    by using separate calls to printf().
2672    
2673    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2674    script, to force use of CR or LF instead of \n in the source. On non-Unix
2675    systems, the value can be set in config.h.
2676    
2677    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2678    absolute limit. Changed the text of the error message to make this clear, and
2679    likewise updated the man page.
2680    
2681    13. The limit of 99 on the number of capturing subpatterns has been removed.
2682    The new limit is 65535, which I hope will not be a "real" limit.
2683    
2684    
2685    Version 3.4 22-Aug-00
2686    ---------------------
2687    
2688    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2689    
2690    2. Diagnose condition (?(0) as an error instead of crashing on matching.
2691    
2692    
2693    Version 3.3 01-Aug-00
2694    ---------------------
2695    
2696    1. If an octal character was given, but the value was greater than \377, it
2697    was not getting masked to the least significant bits, as documented. This could
2698    lead to crashes in some systems.
2699    
2700    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2701    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2702    
2703    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2704    These just pass their arguments on to (pcre_free)(), but they are provided
2705    because some uses of PCRE bind it to non-C systems that can call its functions,
2706    but cannot call free() or pcre_free() directly.
2707    
2708    4. Add "make test" as a synonym for "make check". Corrected some comments in
2709    the Makefile.
2710    
2711    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2712    Makefile.
2713    
2714    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2715    command called pgrep for grepping around the active processes.
2716    
2717    7. Added the beginnings of support for UTF-8 character strings.
2718    
2719    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2720    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2721    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2722    out for the ar command.)
2723    
2724    
2725    Version 3.2 12-May-00
2726    ---------------------
2727    
2728    This is purely a bug fixing release.
2729    
2730    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2731    of ZA. This was just one example of several cases that could provoke this bug,
2732    which was introduced by change 9 of version 2.00. The code for breaking
2733    infinite loops after an iteration that matches an empty string was't working
2734    correctly.
2735    
2736    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2737    when matched against abbab (for example). After matching an empty string, it
2738    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2739    caused it to match further down the string than it should.
2740    
2741    3. The code contained an inclusion of sys/types.h. It isn't clear why this
2742    was there because it doesn't seem to be needed, and it causes trouble on some
2743    systems, as it is not a Standard C header. It has been removed.
2744    
2745    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2746    were reported on the Macintosh. The changes were from
2747    
2748      while ((c = *(++ptr)) != 0 && c != '\n');
2749    to
2750      while ((c = *(++ptr)) != 0 && c != '\n') ;
2751    
2752    Totally extraordinary, but if that's what it takes...
2753    
2754    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2755    available. Added HAVE_BCOPY and an autoconf test for it; if neither
2756    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2757    assumes the way PCRE uses memmove() (always moving upwards).
2758    
2759    6. PCRE is being used in one environment where strchr() is not available. There
2760    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2761    faster code anyway.
2762    
2763    
2764    Version 3.1 09-Feb-00
2765    ---------------------
2766    
2767    The only change in this release is the fixing of some bugs in Makefile.in for
2768    the "install" target:
2769    
2770    (1) It was failing to install pcreposix.h.
2771    
2772    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2773    
2774    
2775    Version 3.0 01-Feb-00
2776    ---------------------
2777    
2778    1. Add support for the /+ modifier to perltest (to output $` like it does in
2779    pcretest).
2780    
2781    2. Add support for the /g modifier to perltest.
2782    
2783    3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2784    matches null strings.
2785    
2786    4. Fix perltest so that it doesn't do unwanted things when fed an empty
2787    pattern. Perl treats empty patterns specially - it reuses the most recent
2788    pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2789    effect.
2790    
2791    5. The POSIX interface was broken in that it was just handing over the POSIX
2792    captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2793    required a bigger vector, with some working space on the end. This means that
2794    the POSIX wrapper now has to get and free some memory, and copy the results.
2795    
2796    6. Added some simple autoconf support, placing the test data and the
2797    documentation in separate directories, re-organizing some of the
2798    information files, and making it build pcre-config (a GNU standard). Also added
2799    libtool support for building PCRE as a shared library, which is now the
2800    default.
2801    
2802    7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2803    09 are not valid octal constants. Single digits will be used for minor values
2804    less than 10.
2805    
2806    8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2807    existing programs that set these in the POSIX interface can use PCRE without
2808    modification.
2809    
2810    9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2811    return all that pcre_info() returns, plus additional data. The pcre_info()
2812    function is retained for compatibility, but is considered to be obsolete.
2813    
2814    10. Added experimental recursion feature (?R) to handle one common case that
2815    Perl 5.6 will be able to do with (?p{...}).
2816    
2817    11. Added support for POSIX character classes like [:alpha:], which Perl is
2818    adopting.
2819    
2820    
2821    Version 2.08 31-Aug-99
2822    ----------------------
2823    
2824    1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2825    trying to match at the startoffset position, but instead was moving forward to
2826    the next newline as if a previous match had failed.
2827    
2828    2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2829    and could get into a loop if a null string was matched other than at the start
2830    of the subject.
2831    
2832    3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2833    be distinguished at compile time, and for completeness also added PCRE_DATE.
2834    
2835    5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2836    in GnuWin32 environments.
2837    
2838    
2839    Version 2.07 29-Jul-99
2840    ----------------------
2841    
2842    1. The documentation is now supplied in plain text form and HTML as well as in
2843    the form of man page sources.
2844    
2845    2. C++ compilers don't like assigning (void *) values to other pointer types.
2846    In particular this affects malloc(). Although there is no problem in Standard
2847    C, I've put in casts to keep C++ compilers happy.
2848    
2849    3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2850    should be (const char *).
2851    
2852    4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2853    be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2854    However, I haven't made this a standard facility. The documentation doesn't
2855    mention it, and the Makefile doesn't support it.
2856    
2857    5. The Makefile now contains an "install" target, with editable destinations at
2858    the top of the file. The pcretest program is not installed.
2859    
2860    6. pgrep -V now gives the PCRE version number and date.
2861    
2862    7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2863    causing the entire string to be ignored, instead of just the last character.
2864    
2865    8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2866    non-matching string, it can take a very, very long time, even for strings of
2867    quite modest length, because of the nested recursion. PCRE now does better in
2868    some of these cases. It does this by remembering the last required literal
2869    character in the pattern, and pre-searching the subject to ensure it is present
2870    before running the real match. In other words, it applies a heuristic to detect
2871    some types of certain failure quickly, and in the above example, if presented
2872    with a string that has no trailing " it gives "no match" very quickly.
2873    
2874    9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2875    other alternatives are tried instead.
2876    
2877    
2878    Version 2.06 09-Jun-99
2879    ----------------------
2880    
2881    1. Change pcretest's output for amount of store used to show just the code
2882    space, because the remainder (the data block) varies in size between 32-bit and
2883    64-bit systems.
2884    
2885    2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2886    start matching at. This allows lookbehinds to work when searching for multiple
2887    occurrences in a string.
2888    
2889    3. Added additional options to pcretest for testing multiple occurrences:
2890    
2891       /+   outputs the rest of the string that follows a match
2892       /g   loops for multiple occurrences, using the new startoffset argument
2893       /G   loops for multiple occurrences by passing an incremented pointer
2894    
2895    4. PCRE wasn't doing the "first character" optimization for patterns starting
2896    with \b or \B, though it was doing it for other lookbehind assertions. That is,
2897    it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2898    the letter 'x'. On long subject strings, this gives a significant speed-up.
2899    
2900    
2901    Version 2.05 21-Apr-99
2902    ----------------------
2903    
2904    1. Changed the type of magic_number from int to long int so that it works
2905    properly on 16-bit systems.
2906    
2907    2. Fixed a bug which caused patterns starting with .* not to work correctly
2908    when the subject string contained newline characters. PCRE was assuming
2909    anchoring for such patterns in all cases, which is not correct because .* will
2910    not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2911    DOTALL is set at top level; otherwise it knows that patterns starting with .*
2912    must be retried after every newline in the subject.
2913    
2914    
2915    Version 2.04 18-Feb-99
2916    ----------------------
2917    
2918    1. For parenthesized subpatterns with repeats whose minimum was zero, the
2919    computation of the store needed to hold the pattern was incorrect (too large).
2920    If such patterns were nested a few deep, this could multiply and become a real
2921    problem.
2922    
2923    2. Added /M option to pcretest to show the memory requirement of a specific
2924    pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2925    
2926    3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2927    compiled in such a way that the backtracking after subsequent failure was
2928    pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2929    ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2930    
2931    
2932    Version 2.03 02-Feb-99
2933    ----------------------
2934    
2935    1. Fixed typo and small mistake in man page.
2936    
2937    2. Added 4th condition (GPL supersedes if conflict) and created separate
2938    LICENCE file containing the conditions.
2939    
2940    3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2941    Perl, that is the internal \ allows the delimiter to be included in the
2942    pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2943    the final delimiter, add \ to the end of the pattern (to test the error).
2944    
2945    4. Added the convenience functions for extracting substrings after a successful
2946    match. Updated pcretest to make it able to test these functions.
2947    
2948    
2949    Version 2.02 14-Jan-99
2950    ----------------------
2951    
2952    1. Initialized the working variables associated with each extraction so that
2953    their saving and restoring doesn't refer to uninitialized store.
2954    
2955    2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2956    compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2957    fix the problem.
2958    
2959    3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2960    calls, and wasn't printing the correct value for compiling calls. Increased the
2961    default value of LOOPREPEAT, and the number of significant figures in the
2962    times.
2963    
2964    4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2965    
2966    5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2967    a building problem on Windows NT with a FAT file system.
2968    
2969    
2970    Version 2.01 21-Oct-98
2971    ----------------------
2972    
2973    1. Changed the API for pcre_compile() to allow for the provision of a pointer
2974    to character tables built by pcre_maketables() in the current locale. If NULL
2975    is passed, the default tables are used.
2976    
2977    
2978    Version 2.00 24-Sep-98
2979    ----------------------
2980    
2981    1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2982    it any more.
2983    
2984    2. Allow quantification of (?>) groups, and make it work correctly.
2985    
2986    3. The first character computation wasn't working for (?>) groups.
2987    
2988    4. Correct the implementation of \Z (it is permitted to match on the \n at the
2989    end of the subject) and add 5.005's \z, which really does match only at the
2990    very end of the subject.
2991    
2992    5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2993    
2994    6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2995    DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2996    localized options. All options to pcre_study() were also removed.
2997    
2998    7. Add other new features from 5.005:
2999    
3000       $(?<=           positive lookbehind
3001       $(?<!           negative lookbehind
3002       (?imsx-imsx)    added the unsetting capability
3003                       such a setting is global if at outer level; local otherwise
3004       (?imsx-imsx:)   non-capturing groups with option setting
3005       (?(cond)re|re)  conditional pattern matching
3006    
3007       A backreference to itself in a repeated group matches the previous
3008       captured string.
3009    
3010    8. General tidying up of studying (both automatic and via "study")
3011    consequential on the addition of new assertions.
3012    
3013    9. As in 5.005, unlimited repeated groups that could match an empty substring
3014    are no longer faulted at compile time. Instead, the loop is forcibly broken at
3015    runtime if any iteration does actually match an empty substring.
3016    
3017    10. Include the RunTest script in the distribution.
3018    
3019    11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3020    discrepancies, some of which were old and were also with respect to 5.004. They
3021    have now been fixed.
3022    
3023    
3024    Version 1.09 28-Apr-98
3025    ----------------------
3026    
3027    1. A negated single character class followed by a quantifier with a minimum
3028    value of one (e.g.  [^x]{1,6}  ) was not compiled correctly. This could lead to
3029    program crashes, or just wrong answers. This did not apply to negated classes
3030    containing more than one character, or to minima other than one.
3031    
3032    
3033    Version 1.08 27-Mar-98
3034    ----------------------
3035    
3036    1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3037    
3038    2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3039    latter must appear before anything that relies on it in the pattern.
3040    
3041    
3042    Version 1.07 16-Feb-98
3043    ----------------------
3044    
3045    1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3046    repeat of a potentially empty string).
3047    
3048    
3049    Version 1.06 23-Jan-98
3050    ----------------------
3051    
3052    1. Added Markus Oberhumer's little patches for C++.
3053    
3054    2. Literal strings longer than 255 characters were broken.
3055    
3056    
3057    Version 1.05 23-Dec-97
3058    ----------------------
3059    
3060    1. Negated character classes containing more than one character were failing if
3061    PCRE_CASELESS was set at run time.
3062    
3063    
3064    Version 1.04 19-Dec-97
3065    ----------------------
3066    
3067    1. Corrected the man page, where some "const" qualifiers had been omitted.
3068    
3069    2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3070    input syntax.
3071    
3072    3. Fixed memory leak which occurred when a regex with back references was
3073    matched with an offsets vector that wasn't big enough. The temporary memory
3074    that is used in this case wasn't being freed if the match failed.
3075    
3076    4. Tidied pcretest to ensure it frees memory that it gets.
3077    
3078    5. Temporary memory was being obtained in the case where the passed offsets
3079    vector was exactly big enough.
3080    
3081    6. Corrected definition of offsetof() from change 5 below.
3082    
3083    7. I had screwed up change 6 below and broken the rules for the use of
3084    setjmp(). Now fixed.
3085    
3086    
3087    Version 1.03 18-Dec-97
3088    ----------------------
3089    
3090    1. A erroneous regex with a missing opening parenthesis was correctly
3091    diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3092    on some systems.
3093    
3094    2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3095    it was reported that one broken compiler failed on the former because "code" is
3096    also an independent variable.
3097    
3098    3. The erroneous regex a[]b caused an array overrun reference.
3099    
3100    4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3101    fail on data ending with that character. (It was going on too far, and checking
3102    the next character, typically a binary zero.) This was specific to the
3103    optimized code for single-character negative classes.
3104    
3105    5. Added a contributed patch from the TIN world which does the following:
3106    
3107      + Add an undef for memmove, in case the the system defines a macro for it.
3108    
3109      + Add a definition of offsetof(), in case there isn't one. (I don't know
3110        the reason behind this - offsetof() is part of the ANSI standard - but
3111        it does no harm).
3112    
3113      + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3114        most of the places where whitespace preceded '#'. I have given up and
3115        allowed the remaining 2 cases to be at the margin.
3116    
3117      + Rename some variables in pcre to eliminate shadowing. This seems very
3118        pedantic, but does no harm, of course.
3119    
3120    6. Moved the call to setjmp() into its own function, to get rid of warnings
3121    from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3122    
3123    7. Constructs such as \d{8,} were compiling into the equivalent of
3124    \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3125    outcome, but in this particular case used more store than had been allocated,
3126    which caused the bug to be discovered because it threw up an internal error.
3127    
3128    8. The debugging code in both pcre and pcretest for outputting the compiled
3129    form of a regex was going wrong in the case of back references followed by
3130    curly-bracketed repeats.
3131    
3132    
3133    Version 1.02 12-Dec-97
3134    ----------------------
3135    
3136    1. Typos in pcre.3 and comments in the source fixed.
3137    
3138    2. Applied a contributed patch to get rid of places where it used to remove
3139    'const' from variables, and fixed some signed/unsigned and uninitialized
3140    variable warnings.
3141    
3142    3. Added the "runtest" target to Makefile.
3143    
3144    4. Set default compiler flag to -O2 rather than just -O.
3145    
3146    
3147    Version 1.01 19-Nov-97
3148    ----------------------
3149    
3150    1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3151    like /([ab]*)*/, that is, for classes with more than one character in them.
3152    
3153    2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3154    as /((?>a*))*/ (a PCRE_EXTRA facility).
3155    
3156    
3157    Version 1.00 18-Nov-97
3158    ----------------------
3159    
3160    1. Added compile-time macros to support systems such as SunOS4 which don't have
3161    memmove() or strerror() but have other things that can be used instead.
3162    
3163    2. Arranged that "make clean" removes the executables.
3164    
3165    
3166  Version 0.99 27-Oct-97  Version 0.99 27-Oct-97
3167  ----------------------  ----------------------
3168    

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