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

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