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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 7.3 05-Jul-07
5    ---------------------
7     1. In the rejigging of the build system that eventually resulted in 7.1, the
8        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
9        brackets there is not right, since it causes compilers to look for an
10        installed pcre.h, not the version that is in the source that is being
11        compiled (which of course may be different). I have changed it back to:
13          #include "pcre.h"
15        I have a vague recollection that the change was concerned with compiling in
16        different directories, but in the new build system, that is taken care of
17        by the VPATH setting the Makefile.
19     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
20        when the subject happened to end in the byte 0x85 (e.g. if the last
21        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
22        characters but of course it shouldn't be taken as a newline when it is part
23        of another character. The bug was that, for an unlimited repeat of . in
24        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
25        characters when looking for a newline.
27     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
29     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
30        in debug output.
32     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
33        long printing in the pcrecpp unittest when running under MinGW.
35     6. ESC_K was left out of the EBCDIC table.
37     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
38        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
39        limit also applies to "virtual nesting" when a pattern is recursive, and in
40        this case 1000 isn't so big. I have been able to remove this limit at the
41        expense of backing off one optimization in certain circumstances. Normally,
42        when pcre_exec() would call its internal match() function recursively and
43        immediately return the result unconditionally, it uses a "tail recursion"
44        feature to save stack. However, when a subpattern that can match an empty
45        string has an unlimited repetition quantifier, it no longer makes this
46        optimization. That gives it a stack frame in which to save the data for
47        checking that an empty string has been matched. Previously this was taken
48        from the 1000-entry workspace that had been reserved. So now there is no
49        explicit limit, but more stack is used.
51     8. Applied Daniel's patches to solve problems with the import/export magic
52        syntax that is required for Windows, and which was going wrong for the
53        pcreposix and pcrecpp parts of the library. These were overlooked when this
54        problem was solved for the main library.
56     9. There were some crude static tests to avoid integer overflow when computing
57        the size of patterns that contain repeated groups with explicit upper
58        limits. As the maximum quantifier is 65535, the maximum group length was
59        set at 30,000 so that the product of these two numbers did not overflow a
60        32-bit integer. However, it turns out that people want to use groups that
61        are longer than 30,000 bytes (though not repeat them that many times).
62        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
63        made it possible to implement the integer overflow checks in a much more
64        dynamic way, which I have now done. The artificial limitation on group
65        length has been removed - we now have only the limit on the total length of
66        the compiled pattern, which depends on the LINK_SIZE setting.
69    Version 7.2 19-Jun-07
70    ---------------------
72     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
73        which is apparently normally available under Windows.
75     2. Re-jig the pcregrep tests with different newline settings in an attempt
76        to make them independent of the local environment's newline setting.
78     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
80     4. Some of the "internals" tests were previously cut out when the link size
81        was not 2, because the output contained actual offsets. The recent new
82        "Z" feature of pcretest means that these can be cut out, making the tests
83        usable with all link sizes.
85     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
86        stack recursion. This gives a massive performance boost under BSD, but just
87        a small improvement under Linux. However, it saves one field in the frame
88        in all cases.
90     6. Added more features from the forthcoming Perl 5.10:
92        (a) (?-n) (where n is a string of digits) is a relative subroutine or
93            recursion call. It refers to the nth most recently opened parentheses.
95        (b) (?+n) is also a relative subroutine call; it refers to the nth next
96            to be opened parentheses.
98        (c) Conditions that refer to capturing parentheses can be specified
99            relatively, for example, (?(-2)... or (?(+3)...
101        (d) \K resets the start of the current match so that everything before
102            is not part of it.
104        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
106        (f) \g{name} is another synonym - part of Perl 5.10's unification of
107            reference syntax.
109        (g) (?| introduces a group in which the numbering of parentheses in each
110            alternative starts with the same number.
112        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
114     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
117     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
118        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
119        for detecting groups that can match an empty string.
121     9. A pattern with a very large number of alternatives (more than several
122        hundred) was running out of internal workspace during the pre-compile
123        phase, where pcre_compile() figures out how much memory will be needed. A
124        bit of new cunning has reduced the workspace needed for groups with
125        alternatives. The 1000-alternative test pattern now uses 12 bytes of
126        workspace instead of running out of the 4096 that are available.
128    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
130    11. Applied patch from Google to remove an optimization that didn't quite work.
131        The report of the bug said:
133          pcrecpp::RE("a*").FullMatch("aaa") matches, while
134          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
135          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
137    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
138        it matched the wrong number of bytes.
141    Version 7.1 24-Apr-07
142    ---------------------
144     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
145        that is more "standard", making use of automake and other Autotools. There
146        is some re-arrangement of the files and adjustment of comments consequent
147        on this.
149     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
150        for recursive directory scanning broke on some systems because the files
151        are not scanned in any specific order and on different systems the order
152        was different. A call to "sort" has been inserted into RunGrepTest for the
153        approprate test as a short-term fix. In the longer term there may be an
154        alternative.
156     3. I had an email from Eric Raymond about problems translating some of PCRE's
157        man pages to HTML (despite the fact that I distribute HTML pages, some
158        people do their own conversions for various reasons). The problems
159        concerned the use of low-level troff macros .br and .in. I have therefore
160        removed all such uses from the man pages (some were redundant, some could
161        be replaced by .nf/.fi pairs). The 132html script that I use to generate
162        HTML has been updated to handle .nf/.fi and to complain if it encounters
163        .br or .in.
165     4. Updated comments in configure.ac that get placed in config.h.in and also
166        arranged for config.h to be included in the distribution, with the name
167        config.h.generic, for the benefit of those who have to compile without
168        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
170     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
171        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
172        makevp.bat for the current PCRE, using the additional files
173        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
175     6. A Windows user reported a minor discrepancy with test 2, which turned out
176        to be caused by a trailing space on an input line that had got lost in his
177        copy. The trailing space was an accident, so I've just removed it.
179     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
180        that is needed.
182     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
183        as "const" (a) because they are and (b) because it helps the PHP
184        maintainers who have recently made a script to detect big data structures
185        in the php code that should be moved to the .rodata section. I remembered
186        to update Builducptable as well, so it won't revert if ucptable.h is ever
187        re-created.
189     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
190        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
191        order to be able to cut out the UTF-8 tables in the latter when UTF-8
192        support is not required. This saves 1.5-2K of code, which is important in
193        some applications.
195        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
196        so as not to refer to the tables, even though these functions will never be
197        called when UTF-8 support is disabled. Otherwise there are problems with a
198        shared library.
200    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
202        (a) It was defining its arguments as char * instead of void *.
204        (b) It was assuming that all moves were upwards in memory; this was true
205            a long time ago when I wrote it, but is no longer the case.
207        The emulated memove() is provided for those environments that have neither
208        memmove() nor bcopy(). I didn't think anyone used it these days, but that
209        is clearly not the case, as these two bugs were recently reported.
211    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
212        and Detrail to create the HTML documentation, the .txt form of the man
213        pages, and it removes trailing spaces from listed files. It also creates
214        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
215        case, it wraps all the #defines with #ifndefs. This script should be run
216        before "make dist".
218    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
219        with Unicode property support.
221        (a) For a maximizing quantifier, if the two different cases of the
222            character were of different lengths in their UTF-8 codings (there are
223            some cases like this - I found 11), and the matching function had to
224            back up over a mixture of the two cases, it incorrectly assumed they
225            were both the same length.
227        (b) When PCRE was configured to use the heap rather than the stack for
228            recursion during matching, it was not correctly preserving the data for
229            the other case of a UTF-8 character when checking ahead for a match
230            while processing a minimizing repeat. If the check also involved
231            matching a wide character, but failed, corruption could cause an
232            erroneous result when trying to check for a repeat of the original
233            character.
235    13. Some tidying changes to the testing mechanism:
237        (a) The RunTest script now detects the internal link size and whether there
238            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
239            values substituted by "configure". (The RunGrepTest script already did
240            this for UTF-8.) The configure.ac script no longer substitutes the
241            relevant variables.
243        (b) The debugging options /B and /D in pcretest show the compiled bytecode
244            with length and offset values. This means that the output is different
245            for different internal link sizes. Test 2 is skipped for link sizes
246            other than 2 because of this, bypassing the problem. Unfortunately,
247            there was also a test in test 3 (the locale tests) that used /B and
248            failed for link sizes other than 2. Rather than cut the whole test out,
249            I have added a new /Z option to pcretest that replaces the length and
250            offset values with spaces. This is now used to make test 3 independent
251            of link size. (Test 2 will be tidied up later.)
253    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
254        segmentation fault instead of returning the appropriate error message.
256    15. In multiline mode when the newline sequence was set to "any", the pattern
257        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
258        This doesn't seem right; it now treats the CRLF combination as the line
259        ending, and so does not match in that case. It's only a pattern such as ^$
260        that would hit this one: something like ^ABC$ would have failed after \r
261        and then tried again after \r\n.
263    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
264        in an attempt to make files that differ only in their line terminators
265        compare equal. This works on Linux.
267    17. Under certain error circumstances pcregrep might try to free random memory
268        as it exited. This is now fixed, thanks to valgrind.
270    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
271        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
272        was because its rules for how to advance for /g after matching an empty
273        string at the end of a line did not allow for this case. They now check for
274        it specially.
276    20. pcretest is supposed to handle patterns and data of any length, by
277        extending its buffers when necessary. It was getting this wrong when the
278        buffer for a data line had to be extended.
280    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
281        CRLF as a newline sequence.
283    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
284        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
285        I have nevertheless tidied it up.
287    23. Added some casts to kill warnings from HP-UX ia64 compiler.
289    24. Added a man page for pcre-config.
292    Version 7.0 19-Dec-06
293    ---------------------
295     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
296        moving to gcc 4.1.1.
298     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
299        sys/time.h, which is documented as needed for this function. It doesn't
300        seem to matter on Linux, but it showed up on some releases of OS X.
302     3. It seems that there are systems where bytes whose values are greater than
303        127 match isprint() in the "C" locale. The "C" locale should be the
304        default when a C program starts up. In most systems, only ASCII printing
305        characters match isprint(). This difference caused the output from pcretest
306        to vary, making some of the tests fail. I have changed pcretest so that:
308        (a) When it is outputting text in the compiled version of a pattern, bytes
309            other than 32-126 are always shown as hex escapes.
311        (b) When it is outputting text that is a matched part of a subject string,
312            it does the same, unless a different locale has been set for the match
313            (using the /L modifier). In this case, it uses isprint() to decide.
315     4. Fixed a major bug that caused incorrect computation of the amount of memory
316        required for a compiled pattern when options that changed within the
317        pattern affected the logic of the preliminary scan that determines the
318        length. The relevant options are -x, and -i in UTF-8 mode. The result was
319        that the computed length was too small. The symptoms of this bug were
320        either the PCRE error "internal error: code overflow" from pcre_compile(),
321        or a glibc crash with a message such as "pcretest: free(): invalid next
322        size (fast)". Examples of patterns that provoked this bug (shown in
323        pcretest format) are:
325          /(?-x: )/x
326          /(?x)(?-x: \s*#\s*)/
327          /((?i)[\x{c0}])/8
328          /(?i:[\x{c0}])/8
330        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
331        is now done differently.
333     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
334        wrapper classes; (b) implement a new function in the C++ scanner that is
335        more efficient than the old way of doing things because it avoids levels of
336        recursion in the regex matching; (c) add a paragraph to the documentation
337        for the FullMatch() function.
339     6. The escape sequence \n was being treated as whatever was defined as
340        "newline". Not only was this contrary to the documentation, which states
341        that \n is character 10 (hex 0A), but it also went horribly wrong when
342        "newline" was defined as CRLF. This has been fixed.
344     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
345        was being set to -1 for the "end of line" case (supposedly a value that no
346        character can have). Though this value is never used (the check for end of
347        line is "zero bytes in current character"), it caused compiler complaints.
348        I've changed it to 0xffffffff.
350     8. In pcre_version.c, the version string was being built by a sequence of
351        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
352        string (as it is for production releases) called a macro with an empty
353        argument. The C standard says the result of this is undefined. The gcc
354        compiler treats it as an empty string (which was what was wanted) but it is
355        reported that Visual C gives an error. The source has been hacked around to
356        avoid this problem.
358     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
359        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
360        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
361        of them did).
363    10. Originally, pcretest opened its input and output without "b"; then I was
364        told that "b" was needed in some environments, so it was added for release
365        5.0 to both the input and output. (It makes no difference on Unix-like
366        systems.) Later I was told that it is wrong for the input on Windows. I've
367        now abstracted the modes into two macros, to make it easier to fiddle with
368        them, and removed "b" from the input mode under Windows.
370    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
372    12. Added -help and --help to pcretest as an official way of being reminded
373        of the options.
375    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
376        and pcrecpp.cc because they annoy compilers at high warning levels.
378    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
380    15. Fixed an occurrence of == in configure.ac that should have been = (shell
381        scripts are not C programs :-) and which was not noticed because it works
382        on Linux.
384    16. pcretest is supposed to handle any length of pattern and data line (as one
385        line or as a continued sequence of lines) by extending its input buffer if
386        necessary. This feature was broken for very long pattern lines, leading to
387        a string of junk being passed to pcre_compile() if the pattern was longer
388        than about 50K.
390    17. I have done a major re-factoring of the way pcre_compile() computes the
391        amount of memory needed for a compiled pattern. Previously, there was code
392        that made a preliminary scan of the pattern in order to do this. That was
393        OK when PCRE was new, but as the facilities have expanded, it has become
394        harder and harder to keep it in step with the real compile phase, and there
395        have been a number of bugs (see for example, 4 above). I have now found a
396        cunning way of running the real compile function in a "fake" mode that
397        enables it to compute how much memory it would need, while actually only
398        ever using a few hundred bytes of working memory and without too many
399        tests of the mode. This should make future maintenance and development
400        easier. A side effect of this work is that the limit of 200 on the nesting
401        depth of parentheses has been removed (though this was never a serious
402        limitation, I suspect). However, there is a downside: pcre_compile() now
403        runs more slowly than before (30% or more, depending on the pattern). I
404        hope this isn't a big issue. There is no effect on runtime performance.
406    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
407        newline (only possible for the last line of a file) and it was a
408        pattern that set a locale (followed by /Lsomething), pcretest crashed.
410    19. Added additional timing features to pcretest. (1) The -tm option now times
411        matching only, not compiling. (2) Both -t and -tm can be followed, as a
412        separate command line item, by a number that specifies the number of
413        repeats to use when timing. The default is 50000; this gives better
414        precision, but takes uncomfortably long for very large patterns.
416    20. Extended pcre_study() to be more clever in cases where a branch of a
417        subpattern has no definite first character. For example, (a*|b*)[cd] would
418        previously give no result from pcre_study(). Now it recognizes that the
419        first character must be a, b, c, or d.
421    21. There was an incorrect error "recursive call could loop indefinitely" if
422        a subpattern (or the entire pattern) that was being tested for matching an
423        empty string contained only one non-empty item after a nested subpattern.
424        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
425        incorrectly, because the \d was being skipped in the check.
427    22. The pcretest program now has a new pattern option /B and a command line
428        option -b, which is equivalent to adding /B to every pattern. This causes
429        it to show the compiled bytecode, without the additional information that
430        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
431        is the same as /B/I).
433    23. A new optimization is now able automatically to treat some sequences such
434        as a*b as a*+b. More specifically, if something simple (such as a character
435        or a simple class like \d) has an unlimited quantifier, and is followed by
436        something that cannot possibly match the quantified thing, the quantifier
437        is automatically "possessified".
439    24. A recursive reference to a subpattern whose number was greater than 39
440        went wrong under certain circumstances in UTF-8 mode. This bug could also
441        have affected the operation of pcre_study().
443    25. Realized that a little bit of performance could be had by replacing
444        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
446    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
448    27. Possessive quantifiers such as a++ were previously implemented by turning
449        them into atomic groups such as ($>a+). Now they have their own opcodes,
450        which improves performance. This includes the automatically created ones
451        from 23 above.
453    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
454        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
455        the first matched character to be a colon. This applied both to named and
456        numbered groups.
458    29. The ucpinternal.h header file was missing its idempotency #ifdef.
460    30. I was sent a "project" file called libpcre.a.dev which I understand makes
461        building PCRE on Windows easier, so I have included it in the distribution.
463    31. There is now a check in pcretest against a ridiculously large number being
464        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
465        loop, the loop is abandoned.
467    32. Forward references to subpatterns in conditions such as (?(2)...) where
468        subpattern 2 is defined later cause pcre_compile() to search forwards in
469        the pattern for the relevant set of parentheses. This search went wrong
470        when there were unescaped parentheses in a character class, parentheses
471        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
473    33. "Subroutine" calls and backreferences were previously restricted to
474        referencing subpatterns earlier in the regex. This restriction has now
475        been removed.
477    34. Added a number of extra features that are going to be in Perl 5.10. On the
478        whole, these are just syntactic alternatives for features that PCRE had
479        previously implemented using the Python syntax or my own invention. The
480        other formats are all retained for compatibility.
482        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
483            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
484            also .NET compatible.
486        (b) A recursion or subroutine call to a named group can now be defined as
487            (?&name) as well as (?P>name).
489        (c) A backreference to a named group can now be defined as \k<name> or
490            \k'name' as well as (?P=name). The new forms, as well as being in Perl
491            5.10, are also .NET compatible.
493        (d) A conditional reference to a named group can now use the syntax
494            (?(<name>) or (?('name') as well as (?(name).
496        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
497            groups (named and numbered) that are never evaluated inline, but can be
498            called as "subroutines" from elsewhere. In effect, the DEFINE condition
499            is always false. There may be only one alternative in such a group.
501        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
502            as the simple (?(R). The condition is true only if the most recent
503            recursion is that of the given number or name. It does not search out
504            through the entire recursion stack.
506        (g) The escape \gN or \g{N} has been added, where N is a positive or
507            negative number, specifying an absolute or relative reference.
509    35. Tidied to get rid of some further signed/unsigned compiler warnings and
510        some "unreachable code" warnings.
512    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
513        things, this adds five new scripts.
515    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
516        There were also incompatibilities regarding the handling of \Q..\E inside
517        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
518        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
520    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
521        matches an empty string, and forcibly breaks the loop. There were bugs in
522        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
523        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
524        separate and independent bugs (that affected different cases) have been
525        fixed.
527    39. Refactored the code to abolish the use of different opcodes for small
528        capturing bracket numbers. This is a tidy that I avoided doing when I
529        removed the limit on the number of capturing brackets for 3.5 back in 2001.
530        The new approach is not only tidier, it makes it possible to reduce the
531        memory needed to fix the previous bug (38).
533    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
534        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
535        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
536        mode.
538    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
539        report.
541    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
542        copy construction and assignment in the C++ wrapper.
544    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
545        couple of bugs that could have given wrong results in the "--newline=crlf"
546        case.
548    44. Added a number of casts and did some reorganization of signed/unsigned int
549        variables following suggestions from Dair Grant. Also renamed the variable
550        "this" as "item" because it is a C++ keyword.
552    45. Arranged for dftables to add
554          #include "pcre_internal.h"
556        to pcre_chartables.c because without it, gcc 4.x may remove the array
557        definition from the final binary if PCRE is built into a static library and
558        dead code stripping is activated.
560    46. For an unanchored pattern, if a match attempt fails at the start of a
561        newline sequence, and the newline setting is CRLF or ANY, and the next two
562        characters are CRLF, advance by two characters instead of one.
565    Version 6.7 04-Jul-06
566    ---------------------
568     1. In order to handle tests when input lines are enormously long, pcretest has
569        been re-factored so that it automatically extends its buffers when
570        necessary. The code is crude, but this _is_ just a test program. The
571        default size has been increased from 32K to 50K.
573     2. The code in pcre_study() was using the value of the re argument before
574        testing it for NULL. (Of course, in any sensible call of the function, it
575        won't be NULL.)
577     3. The memmove() emulation function in pcre_internal.h, which is used on
578        systems that lack both memmove() and bcopy() - that is, hardly ever -
579        was missing a "static" storage class specifier.
581     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
582        containing an extended class (one that cannot be represented by a bitmap
583        because it contains high-valued characters or Unicode property items, e.g.
584        [\pZ]). Almost always one would set UTF-8 mode when processing such a
585        pattern, but PCRE should not loop if you do not (it no longer does).
586        [Detail: two cases were found: (a) a repeated subpattern containing an
587        extended class; (b) a recursive reference to a subpattern that followed a
588        previous extended class. It wasn't skipping over the extended class
589        correctly when UTF-8 mode was not set.]
591     5. A negated single-character class was not being recognized as fixed-length
592        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
593        compile error "lookbehind assertion is not fixed length".
595     6. The RunPerlTest auxiliary script was showing an unexpected difference
596        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
597        write a Perl script that can interpret lines of an input file either as
598        byte characters or as UTF-8, which is what "perltest" was being required to
599        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
600        can't do is switch easily at run time between having the "use utf8;" pragma
601        or not. In the end, I fudged it by using the RunPerlTest script to insert
602        "use utf8;" explicitly for the UTF-8 tests.
604     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
605        the end of the subject string, contrary to the documentation and to what
606        Perl does. This was true of both matching functions. Now it matches only at
607        the start of the subject and immediately after *internal* newlines.
609     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
610        a pointer to an int instead of a pointer to an unsigned long int. This
611        caused problems on 64-bit systems.
613     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
614        instance of the 'standard' template library not being so standard".
616    10. There was no check on the number of named subpatterns nor the maximum
617        length of a subpattern name. The product of these values is used to compute
618        the size of the memory block for a compiled pattern. By supplying a very
619        long subpattern name and a large number of named subpatterns, the size
620        computation could be caused to overflow. This is now prevented by limiting
621        the length of names to 32 characters, and the number of named subpatterns
622        to 10,000.
624    11. Subpatterns that are repeated with specific counts have to be replicated in
625        the compiled pattern. The size of memory for this was computed from the
626        length of the subpattern and the repeat count. The latter is limited to
627        65535, but there was no limit on the former, meaning that integer overflow
628        could in principle occur. The compiled length of a repeated subpattern is
629        now limited to 30,000 bytes in order to prevent this.
631    12. Added the optional facility to have named substrings with the same name.
633    13. Added the ability to use a named substring as a condition, using the
634        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
635        are numbers (not recommended). Forward references are permitted.
637    14. Added forward references in named backreferences (if you see what I mean).
639    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
640        pattern could run off the end of the subject. For example, the pattern
641        "(?s)(.{1,5})"8 did this with the subject "ab".
643    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
644        PCRE_CASELESS was set when matching characters that were quantified with ?
645        or *.
647    17. A character class other than a single negated character that had a minimum
648        but no maximum quantifier - for example [ab]{6,} - was not handled
649        correctly by pce_dfa_exec(). It would match only one character.
651    18. A valid (though odd) pattern that looked like a POSIX character
652        class but used an invalid character after [ (for example [[,abc,]]) caused
653        pcre_compile() to give the error "Failed: internal error: code overflow" or
654        in some cases to crash with a glibc free() error. This could even happen if
655        the pattern terminated after [[ but there just happened to be a sequence of
656        letters, a binary zero, and a closing ] in the memory that followed.
658    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
659        over the years. Originally (before any Unicode support), just the bottom 8
660        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
661        output from "man perlunicode" includes this:
663          The regular expression compiler produces polymorphic opcodes.  That
664          is, the pattern adapts to the data and automatically switches to
665          the Unicode character scheme when presented with Unicode data--or
666          instead uses a traditional byte scheme when presented with byte
667          data.
669        Sadly, a wide octal escape does not cause a switch, and in a string with
670        no other multibyte characters, these octal escapes are treated as before.
671        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
672        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
673        Unicode string.
675        I have not perpetrated such confusion in PCRE. Up till now, it took just
676        the bottom 8 bits, as in old Perl. I have now made octal escapes with
677        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
678        translate to the appropriate multibyte character.
680    29. Applied some refactoring to reduce the number of warnings from Microsoft
681        and Borland compilers. This has included removing the fudge introduced
682        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
683        a warning about an unused variable.
685    21. PCRE has not included VT (character 0x0b) in the set of whitespace
686        characters since release 4.0, because Perl (from release 5.004) does not.
687        [Or at least, is documented not to: some releases seem to be in conflict
688        with the documentation.] However, when a pattern was studied with
689        pcre_study() and all its branches started with \s, PCRE still included VT
690        as a possible starting character. Of course, this did no harm; it just
691        caused an unnecessary match attempt.
693    22. Removed a now-redundant internal flag bit that recorded the fact that case
694        dependency changed within the pattern. This was once needed for "required
695        byte" processing, but is no longer used. This recovers a now-scarce options
696        bit. Also moved the least significant internal flag bit to the most-
697        significant bit of the word, which was not previously used (hangover from
698        the days when it was an int rather than a uint) to free up another bit for
699        the future.
701    23. Added support for CRLF line endings as well as CR and LF. As well as the
702        default being selectable at build time, it can now be changed at runtime
703        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
704        specify that it is scanning data with non-default line endings.
706    24. Changed the definition of CXXLINK to make it agree with the definition of
707        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
709    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
710        recursions. This makes a big different to stack usage for some patterns.
712    26. If a subpattern containing a named recursion or subroutine reference such
713        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
714        the space required for the compiled pattern went wrong and gave too small a
715        value. Depending on the environment, this could lead to "Failed: internal
716        error: code overflow at offset 49" or "glibc detected double free or
717        corruption" errors.
719    27. Applied patches from Google (a) to support the new newline modes and (b) to
720        advance over multibyte UTF-8 characters in GlobalReplace.
722    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
723        difference for some implementation of PCRE in some Windows version.
725    29. Added some extra testing facilities to pcretest:
727        \q<number>   in a data line sets the "match limit" value
728        \Q<number>   in a data line sets the "match recursion limt" value
729        -S <number>  sets the stack size, where <number> is in megabytes
731        The -S option isn't available for Windows.
734    Version 6.6 06-Feb-06
735    ---------------------
737     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
738        in pcreposix.h. I have copied the definition from pcre.h.
740     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
741        because pcre.h is no longer a built file.
743     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
744        not normally included in the compiled code.
747    Version 6.5 01-Feb-06
748    ---------------------
750     1. When using the partial match feature with pcre_dfa_exec(), it was not
751        anchoring the second and subsequent partial matches at the new starting
752        point. This could lead to incorrect results. For example, with the pattern
753        /1234/, partially matching against "123" and then "a4" gave a match.
755     2. Changes to pcregrep:
757        (a) All non-match returns from pcre_exec() were being treated as failures
758            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
759            error message is output. Some extra information is given for the
760            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
761            probably the only errors that are likely to be caused by users (by
762            specifying a regex that has nested indefinite repeats, for instance).
763            If there are more than 20 of these errors, pcregrep is abandoned.
765        (b) A binary zero was treated as data while matching, but terminated the
766            output line if it was written out. This has been fixed: binary zeroes
767            are now no different to any other data bytes.
769        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
770            used to set a locale for matching. The --locale=xxxx long option has
771            been added (no short equivalent) to specify a locale explicitly on the
772            pcregrep command, overriding the environment variables.
774        (d) When -B was used with -n, some line numbers in the output were one less
775            than they should have been.
777        (e) Added the -o (--only-matching) option.
779        (f) If -A or -C was used with -c (count only), some lines of context were
780            accidentally printed for the final match.
782        (g) Added the -H (--with-filename) option.
784        (h) The combination of options -rh failed to suppress file names for files
785            that were found from directory arguments.
787        (i) Added the -D (--devices) and -d (--directories) options.
789        (j) Added the -F (--fixed-strings) option.
791        (k) Allow "-" to be used as a file name for -f as well as for a data file.
793        (l) Added the --colo(u)r option.
795        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
796            is not present by default.
798     3. A nasty bug was discovered in the handling of recursive patterns, that is,
799        items such as (?R) or (?1), when the recursion could match a number of
800        alternatives. If it matched one of the alternatives, but subsequently,
801        outside the recursion, there was a failure, the code tried to back up into
802        the recursion. However, because of the way PCRE is implemented, this is not
803        possible, and the result was an incorrect result from the match.
805        In order to prevent this happening, the specification of recursion has
806        been changed so that all such subpatterns are automatically treated as
807        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
809     4. I had overlooked the fact that, in some locales, there are characters for
810        which isalpha() is true but neither isupper() nor islower() are true. In
811        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
812        and ordfeminine) are like this. This affected the treatment of \w and \W
813        when they appeared in character classes, but not when they appeared outside
814        a character class. The bit map for "word" characters is now created
815        separately from the results of isalnum() instead of just taking it from the
816        upper, lower, and digit maps. (Plus the underscore character, of course.)
818     5. The above bug also affected the handling of POSIX character classes such as
819        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
820        permanent tables. Instead, the bit maps for such a class were previously
821        created as the appropriate unions of the upper, lower, and digit bitmaps.
822        Now they are created by subtraction from the [[:word:]] class, which has
823        its own bitmap.
825     6. The [[:blank:]] character class matches horizontal, but not vertical space.
826        It is created by subtracting the vertical space characters (\x09, \x0a,
827        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
828        subtraction was done in the overall bitmap for a character class, meaning
829        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
830        be recognized. This bug has been fixed.
832     7. Patches from the folks at Google:
834          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
835          real life, but is still worth protecting against".
837          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
838          regular expressions".
840          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
841          have it.
843          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
844          "configure" and the latter not, in order to fix a problem somebody had
845          with compiling the Arg class on HP-UX.
847          (e) Improve the error-handling of the C++ wrapper a little bit.
849          (f) New tests for checking recursion limiting.
851     8. The pcre_memmove() function, which is used only if the environment does not
852        have a standard memmove() function (and is therefore rarely compiled),
853        contained two bugs: (a) use of int instead of size_t, and (b) it was not
854        returning a result (though PCRE never actually uses the result).
856     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
857        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
858        returned instead of calling malloc() with an overflowing number that would
859        most likely cause subsequent chaos.
861    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
863    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
864        with this option is matched, the nmatch and pmatch options of regexec() are
865        ignored.
867    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
868        provided in case anyone wants to the the POSIX interface with UTF-8
869        strings.
871    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
872        C++ linking (needed for some HP-UX environments).
874    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
875        (unused parameter) and in the pcre_printint() function (omitted "default"
876        switch label when the default is to do nothing).
878    15. Added some code to make it possible, when PCRE is compiled as a C++
879        library, to replace subject pointers for pcre_exec() with a smart pointer
880        class, thus making it possible to process discontinuous strings.
882    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
883        much the same function. They were added by different people who were trying
884        to make PCRE easy to compile on non-Unix systems. It has been suggested
885        that PCRE_EXPORT be abolished now that there is more automatic apparatus
886        for compiling on Windows systems. I have therefore replaced it with
887        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
888        defaults to "extern" for C or "extern C" for C++, which works fine on
889        Unix-like systems. It is now possible to override the value of PCRE_DATA_
890        SCOPE with something explicit in config.h. In addition:
892        (a) pcreposix.h still had just "extern" instead of either of these macros;
893            I have replaced it with PCRE_DATA_SCOPE.
895        (b) Functions such as _pcre_xclass(), which are internal to the library,
896            but external in the C sense, all had PCRE_EXPORT in their definitions.
897            This is apparently wrong for the Windows case, so I have removed it.
898            (It makes no difference on Unix-like systems.)
900    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
901        of recursive calls to match(). This is different to MATCH_LIMIT because
902        that limits the total number of calls to match(), not all of which increase
903        the depth of recursion. Limiting the recursion depth limits the amount of
904        stack (or heap if NO_RECURSE is set) that is used. The default can be set
905        when PCRE is compiled, and changed at run time. A patch from Google adds
906        this functionality to the C++ interface.
908    18. Changes to the handling of Unicode character properties:
910        (a) Updated the table to Unicode 4.1.0.
912        (b) Recognize characters that are not in the table as "Cn" (undefined).
914        (c) I revised the way the table is implemented to a much improved format
915            which includes recognition of ranges. It now supports the ranges that
916            are defined in UnicodeData.txt, and it also amalgamates other
917            characters into ranges. This has reduced the number of entries in the
918            table from around 16,000 to around 3,000, thus reducing its size
919            considerably. I realized I did not need to use a tree structure after
920            all - a binary chop search is just as efficient. Having reduced the
921            number of entries, I extended their size from 6 bytes to 8 bytes to
922            allow for more data.
924        (d) Added support for Unicode script names via properties such as \p{Han}.
926    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
927        matching that character.
929    20. When matching a repeated Unicode property with a minimum greater than zero,
930        (for example \pL{2,}), PCRE could look past the end of the subject if it
931        reached it while seeking the minimum number of characters. This could
932        happen only if some of the characters were more than one byte long, because
933        there is a check for at least the minimum number of bytes.
935    21. Refactored the implementation of \p and \P so as to be more general, to
936        allow for more different types of property in future. This has changed the
937        compiled form incompatibly. Anybody with saved compiled patterns that use
938        \p or \P will have to recompile them.
940    22. Added "Any" and "L&" to the supported property types.
942    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
943        but give a compile time error if the value is greater than 0xff.
945    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
946        accidentally not being installed or uninstalled.
948    25. The pcre.h file was built from pcre.h.in, but the only changes that were
949        made were to insert the current release number. This seemed silly, because
950        it made things harder for people building PCRE on systems that don't run
951        "configure". I have turned pcre.h into a distributed file, no longer built
952        by "configure", with the version identification directly included. There is
953        no longer a pcre.h.in file.
955        However, this change necessitated a change to the pcre-config script as
956        well. It is built from pcre-config.in, and one of the substitutions was the
957        release number. I have updated configure.ac so that ./configure now finds
958        the release number by grepping pcre.h.
960    26. Added the ability to run the tests under valgrind.
963    Version 6.4 05-Sep-05
964    ---------------------
966     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
967        "--" to be printed when multiple files were scanned, even when none of the
968        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
969        consider it to be a bug, and have restored the previous behaviour.
971     2. A couple of code tidies to get rid of compiler warnings.
973     3. The pcretest program used to cheat by referring to symbols in the library
974        whose names begin with _pcre_. These are internal symbols that are not
975        really supposed to be visible externally, and in some environments it is
976        possible to suppress them. The cheating is now confined to including
977        certain files from the library's source, which is a bit cleaner.
979     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
980        file's purpose clearer.
982     5. Reorganized pcre_ucp_findchar().
985    Version 6.3 15-Aug-05
986    ---------------------
988     1. The file libpcre.pc.in did not have general read permission in the tarball.
990     2. There were some problems when building without C++ support:
992        (a) If C++ support was not built, "make install" and "make test" still
993            tried to test it.
995        (b) There were problems when the value of CXX was explicitly set. Some
996            changes have been made to try to fix these, and ...
998        (c) --disable-cpp can now be used to explicitly disable C++ support.
1000        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1001            backslash in a target when C++ was disabled. This confuses some
1002            versions of "make", apparently. Using an intermediate variable solves
1003            this. (Same for CPP_LOBJ.)
1005     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1006        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1007        necessary on certain architectures.
1009     4. Added a setting of -export-symbols-regex to the link command to remove
1010        those symbols that are exported in the C sense, but actually are local
1011        within the library, and not documented. Their names all begin with
1012        "_pcre_". This is not a perfect job, because (a) we have to except some
1013        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1014        available (and never for static libraries). I have made a note to try to
1015        find a way round (a) in the future.
1018    Version 6.2 01-Aug-05
1019    ---------------------
1021     1. There was no test for integer overflow of quantifier values. A construction
1022        such as {1111111111111111} would give undefined results. What is worse, if
1023        a minimum quantifier for a parenthesized subpattern overflowed and became
1024        negative, the calculation of the memory size went wrong. This could have
1025        led to memory overwriting.
1027     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1029     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1030        operating environments where this matters.
1032     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1033        PCRE options from within the C++ wrapper.
1035     5. Named capturing subpatterns were not being correctly counted when a pattern
1036        was compiled. This caused two problems: (a) If there were more than 100
1037        such subpatterns, the calculation of the memory needed for the whole
1038        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1039        back references of the form \12, where the number was greater than 9, were
1040        not recognized as back references, even though there were sufficient
1041        previous subpatterns.
1043     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1044        versions of gcc, e.g. 2.95.4.
1047    Version 6.1 21-Jun-05
1048    ---------------------
1050     1. There was one reference to the variable "posix" in pcretest.c that was not
1051        surrounded by "#if !defined NOPOSIX".
1053     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1054        the cross-check on the old pcre_info() function, for the benefit of the
1055        cut-down version of PCRE that is currently imported into Exim.
1057     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1058        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1059        patterns that start (?i) but I don't think that matters. The use of (?i) is
1060        just an example; this all applies to the other options as well.
1062     4. Since libtool seems to echo the compile commands it is issuing, the output
1063        from "make" can be reduced a bit by putting "@" in front of each libtool
1064        compile command.
1066     5. Patch from the folks at Google for configure.in to be a bit more thorough
1067        in checking for a suitable C++ installation before trying to compile the
1068        C++ stuff. This should fix a reported problem when a compiler was present,
1069        but no suitable headers.
1071     6. The man pages all had just "PCRE" as their title. I have changed them to
1072        be the relevant file name. I have also arranged that these names are
1073        retained in the file doc/pcre.txt, which is a concatenation in text format
1074        of all the man pages except the little individual ones for each function.
1076     7. The NON-UNIX-USE file had not been updated for the different set of source
1077        files that come with release 6. I also added a few comments about the C++
1078        wrapper.
1081    Version 6.0 07-Jun-05
1082    ---------------------
1084     1. Some minor internal re-organization to help with my DFA experiments.
1086     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1087        didn't matter for the library itself when fully configured, but did matter
1088        when compiling without UCP support, or within Exim, where the ucp files are
1089        not imported.
1091     3. Refactoring of the library code to split up the various functions into
1092        different source modules. The addition of the new DFA matching code (see
1093        below) to a single monolithic source would have made it really too
1094        unwieldy, quite apart from causing all the code to be include in a
1095        statically linked application, when only some functions are used. This is
1096        relevant even without the DFA addition now that patterns can be compiled in
1097        one application and matched in another.
1099        The downside of splitting up is that there have to be some external
1100        functions and data tables that are used internally in different modules of
1101        the library but which are not part of the API. These have all had their
1102        names changed to start with "_pcre_" so that they are unlikely to clash
1103        with other external names.
1105     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1106        a different (DFA) algorithm. Although it is slower than the original
1107        function, it does have some advantages for certain types of matching
1108        problem.
1110     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1111        including restarting after a partial match.
1113     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1114        defined when compiling for Windows was sent to me. I have put it into the
1115        code, though I have no means of testing or verifying it.
1117     7. Added the pcre_refcount() auxiliary function.
1119     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1120        match before or at the first newline in the subject string. In pcretest,
1121        the /f option on a pattern can be used to set this.
1123     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1124        would behave wrongly. This has been present in PCRE since release 4.0.
1126    10. A number of changes to the pcregrep command:
1128        (a) Refactored how -x works; insert ^(...)$ instead of setting
1129            PCRE_ANCHORED and checking the length, in preparation for adding
1130            something similar for -w.
1132        (b) Added the -w (match as a word) option.
1134        (c) Refactored the way lines are read and buffered so as to have more
1135            than one at a time available.
1137        (d) Implemented a pcregrep test script.
1139        (e) Added the -M (multiline match) option. This allows patterns to match
1140            over several lines of the subject. The buffering ensures that at least
1141            8K, or the rest of the document (whichever is the shorter) is available
1142            for matching (and similarly the previous 8K for lookbehind assertions).
1144        (f) Changed the --help output so that it now says
1146              -w, --word-regex(p)
1148            instead of two lines, one with "regex" and the other with "regexp"
1149            because that confused at least one person since the short forms are the
1150            same. (This required a bit of code, as the output is generated
1151            automatically from a table. It wasn't just a text change.)
1153        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1154            option but starts with a hyphen. Could be a pattern or a path name
1155            starting with a hyphen, for instance.
1157        (h) "-" can be given as a file name to represent stdin.
1159        (i) When file names are being printed, "(standard input)" is used for
1160            the standard input, for compatibility with GNU grep. Previously
1161            "<stdin>" was used.
1163        (j) The option --label=xxx can be used to supply a name to be used for
1164            stdin when file names are being printed. There is no short form.
1166        (k) Re-factored the options decoding logic because we are going to add
1167            two more options that take data. Such options can now be given in four
1168            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1170        (l) Added the -A, -B, and -C options for requesting that lines of context
1171            around matches be printed.
1173        (m) Added the -L option to print the names of files that do not contain
1174            any matching lines, that is, the complement of -l.
1176        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1177            continue to scan other files.
1179        (o) The -s option was incorrectly implemented. For compatibility with other
1180            greps, it now suppresses the error message for a non-existent or non-
1181            accessible file (but not the return code). There is a new option called
1182            -q that suppresses the output of matching lines, which was what -s was
1183            previously doing.
1185        (p) Added --include and --exclude options to specify files for inclusion
1186            and exclusion when recursing.
1188    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1189        Hopefully, it now does.
1191    12. Missing cast in pcre_study().
1193    13. Added an "uninstall" target to the makefile.
1195    14. Replaced "extern" in the function prototypes in Makefile.in with
1196        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1197        world, but is set differently for Windows.
1199    15. Added a second compiling function called pcre_compile2(). The only
1200        difference is that it has an extra argument, which is a pointer to an
1201        integer error code. When there is a compile-time failure, this is set
1202        non-zero, in addition to the error test pointer being set to point to an
1203        error message. The new argument may be NULL if no error number is required
1204        (but then you may as well call pcre_compile(), which is now just a
1205        wrapper). This facility is provided because some applications need a
1206        numeric error indication, but it has also enabled me to tidy up the way
1207        compile-time errors are handled in the POSIX wrapper.
1209    16. Added VPATH=.libs to the makefile; this should help when building with one
1210        prefix path and installing with another. (Or so I'm told by someone who
1211        knows more about this stuff than I do.)
1213    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1214        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1215        match everything, including newlines. This is not POSIX-compatible, but
1216        somebody wanted the feature. From pcretest it can be activated by using
1217        both the P and the s flags.
1219    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1221    19. libpcre.pc was being incorrectly installed as executable.
1223    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1224        it now also looks for '\r' so that it will work unmodified on Windows.
1226    21. Added Google's contributed C++ wrapper to the distribution.
1228    22. Added some untidy missing memory free() calls in pcretest, to keep
1229        Electric Fence happy when testing.
1233    Version 5.0 13-Sep-04
1234    ---------------------
1236     1. Internal change: literal characters are no longer packed up into items
1237        containing multiple characters in a single byte-string. Each character
1238        is now matched using a separate opcode. However, there may be more than one
1239        byte in the character in UTF-8 mode.
1241     2. The pcre_callout_block structure has two new fields: pattern_position and
1242        next_item_length. These contain the offset in the pattern to the next match
1243        item, and its length, respectively.
1245     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1246        insertion of callouts before each pattern item. Added the /C option to
1247        pcretest to make use of this.
1249     4. On the advice of a Windows user, the lines
1251          #if defined(_WIN32) || defined(WIN32)
1252          _setmode( _fileno( stdout ), 0x8000 );
1253          #endif  /* defined(_WIN32) || defined(WIN32) */
1255        have been added to the source of pcretest. This apparently does useful
1256        magic in relation to line terminators.
1258     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1259        for the benefit of those environments where the "b" makes a difference.
1261     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1262        to know about it. I have put a hack into configure.in that adds in code
1263        to set GCC=yes if CC=icc. This seems to end up at a point in the
1264        generated configure script that is early enough to affect the setting of
1265        compiler options, which is what is needed, but I have no means of testing
1266        whether it really works. (The user who reported this had patched the
1267        generated configure script, which of course I cannot do.)
1269        LATER: After change 22 below (new libtool files), the configure script
1270        seems to know about icc (and also ecc). Therefore, I have commented out
1271        this hack in configure.in.
1273     7. Added support for pkg-config (2 patches were sent in).
1275     8. Negated POSIX character classes that used a combination of internal tables
1276        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1277        [[:^ascii]]. Typically, they would match almost any characters. The other
1278        POSIX classes were not broken in this way.
1280     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1281        to find the match, as PCRE was deluded into thinking that the match had to
1282        start at the start point or following a newline. The same bug applied to
1283        patterns with negative forward assertions or any backward assertions
1284        preceding ".*" at the start, unless the pattern required a fixed first
1285        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1287    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1288        starting at the last subject character, bytes beyond the end of the subject
1289        string were read.
1291    11. Renamed the variable "class" as "classbits" to make life easier for C++
1292        users. (Previously there was a macro definition, but it apparently wasn't
1293        enough.)
1295    12. Added the new field "tables" to the extra data so that tables can be passed
1296        in at exec time, or the internal tables can be re-selected. This allows
1297        a compiled regex to be saved and re-used at a later time by a different
1298        program that might have everything at different addresses.
1300    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1301        -R library as well as a -L library.
1303    14. The debugging options of pcretest (-d on the command line or D on a
1304        pattern) showed incorrect output for anything following an extended class
1305        that contained multibyte characters and which was followed by a quantifier.
1307    15. Added optional support for general category Unicode character properties
1308        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1309        support. It adds about 90K to the size of the library. The meanings of the
1310        inbuilt class escapes such as \d and \s have NOT been changed.
1312    16. Updated pcredemo.c to include calls to free() to release the memory for the
1313        compiled pattern.
1315    17. The generated file chartables.c was being created in the source directory
1316        instead of in the building directory. This caused the build to fail if the
1317        source directory was different from the building directory, and was
1318        read-only.
1320    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1321        file. No doubt somebody will tell me if they don't make sense... Also added
1322        Dan Mooney's comments about building on OpenVMS.
1324    19. Added support for partial matching via the PCRE_PARTIAL option for
1325        pcre_exec() and the \P data escape in pcretest.
1327    20. Extended pcretest with 3 new pattern features:
1329        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1330              write the compiled pattern to the file whose name is "rest-of-line".
1331              This is a straight binary dump of the data, with the saved pointer to
1332              the character tables forced to be NULL. The study data, if any, is
1333              written too. After writing, pcretest reads a new pattern.
1335        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1336              compiled pattern from the given file. There must not be any
1337              occurrences of "<" in the file name (pretty unlikely); if there are,
1338              pcretest will instead treat the initial "<" as a pattern delimiter.
1339              After reading in the pattern, pcretest goes on to read data lines as
1340              usual.
1342        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1343              and 16-bit fields in a compiled pattern, to simulate a pattern that
1344              was compiled on a host of opposite endianness.
1346    21. The pcre-exec() function can now cope with patterns that were compiled on
1347        hosts of opposite endianness, with this restriction:
1349          As for any compiled expression that is saved and used later, the tables
1350          pointer field cannot be preserved; the extra_data field in the arguments
1351          to pcre_exec() should be used to pass in a tables address if a value
1352          other than the default internal tables were used at compile time.
1354    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1355        now diagnosed as an error. Previously, most of the time, a negative number
1356        would have been treated as zero, but if in addition "ovector" was passed as
1357        NULL, a crash could occur.
1359    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1360        new versions from the libtool 1.5 distribution (the last one is a copy of
1361        a file called libtool.m4). This seems to have fixed the need to patch
1362        "configure" to support Darwin 1.3 (which I used to do). However, I still
1363        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1364        workstation).
1366    24. Changed the PCRE licence to be the more standard "BSD" licence.
1369  Version 4.5 01-Dec-03  Version 4.5 01-Dec-03
1370  ---------------------  ---------------------

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