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

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