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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" for long printing in the pcrecpp
33        unittest when running under MinGW.
34    
35     6. ESC_K was left out of the EBCDIC table.
36    
37    
38    
39    Version 7.2 19-Jun-07
40    ---------------------
41    
42     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
43        which is apparently normally available under Windows.
44    
45     2. Re-jig the pcregrep tests with different newline settings in an attempt
46        to make them independent of the local environment's newline setting.
47    
48     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
49    
50     4. Some of the "internals" tests were previously cut out when the link size
51        was not 2, because the output contained actual offsets. The recent new
52        "Z" feature of pcretest means that these can be cut out, making the tests
53        usable with all link sizes.
54    
55     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
56        stack recursion. This gives a massive performance boost under BSD, but just
57        a small improvement under Linux. However, it saves one field in the frame
58        in all cases.
59    
60     6. Added more features from the forthcoming Perl 5.10:
61    
62        (a) (?-n) (where n is a string of digits) is a relative subroutine or
63            recursion call. It refers to the nth most recently opened parentheses.
64    
65        (b) (?+n) is also a relative subroutine call; it refers to the nth next
66            to be opened parentheses.
67    
68        (c) Conditions that refer to capturing parentheses can be specified
69            relatively, for example, (?(-2)... or (?(+3)...
70    
71        (d) \K resets the start of the current match so that everything before
72            is not part of it.
73    
74        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
75    
76        (f) \g{name} is another synonym - part of Perl 5.10's unification of
77            reference syntax.
78    
79        (g) (?| introduces a group in which the numbering of parentheses in each
80            alternative starts with the same number.
81    
82        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
83    
84     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
85        PCRE_INFO_JCHANGED.
86    
87     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
88        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
89        for detecting groups that can match an empty string.
90    
91     9. A pattern with a very large number of alternatives (more than several
92        hundred) was running out of internal workspace during the pre-compile
93        phase, where pcre_compile() figures out how much memory will be needed. A
94        bit of new cunning has reduced the workspace needed for groups with
95        alternatives. The 1000-alternative test pattern now uses 12 bytes of
96        workspace instead of running out of the 4096 that are available.
97    
98    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
99    
100    11. Applied patch from Google to remove an optimization that didn't quite work.
101        The report of the bug said:
102    
103          pcrecpp::RE("a*").FullMatch("aaa") matches, while
104          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
105          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
106    
107    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
108        it matched the wrong number of bytes.
109    
110    
111    Version 7.1 24-Apr-07
112    ---------------------
113    
114     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
115        that is more "standard", making use of automake and other Autotools. There
116        is some re-arrangement of the files and adjustment of comments consequent
117        on this.
118    
119     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
120        for recursive directory scanning broke on some systems because the files
121        are not scanned in any specific order and on different systems the order
122        was different. A call to "sort" has been inserted into RunGrepTest for the
123        approprate test as a short-term fix. In the longer term there may be an
124        alternative.
125    
126     3. I had an email from Eric Raymond about problems translating some of PCRE's
127        man pages to HTML (despite the fact that I distribute HTML pages, some
128        people do their own conversions for various reasons). The problems
129        concerned the use of low-level troff macros .br and .in. I have therefore
130        removed all such uses from the man pages (some were redundant, some could
131        be replaced by .nf/.fi pairs). The 132html script that I use to generate
132        HTML has been updated to handle .nf/.fi and to complain if it encounters
133        .br or .in.
134    
135     4. Updated comments in configure.ac that get placed in config.h.in and also
136        arranged for config.h to be included in the distribution, with the name
137        config.h.generic, for the benefit of those who have to compile without
138        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
139    
140     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
141        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
142        makevp.bat for the current PCRE, using the additional files
143        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
144    
145     6. A Windows user reported a minor discrepancy with test 2, which turned out
146        to be caused by a trailing space on an input line that had got lost in his
147        copy. The trailing space was an accident, so I've just removed it.
148    
149     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
150        that is needed.
151    
152     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
153        as "const" (a) because they are and (b) because it helps the PHP
154        maintainers who have recently made a script to detect big data structures
155        in the php code that should be moved to the .rodata section. I remembered
156        to update Builducptable as well, so it won't revert if ucptable.h is ever
157        re-created.
158    
159     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
160        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
161        order to be able to cut out the UTF-8 tables in the latter when UTF-8
162        support is not required. This saves 1.5-2K of code, which is important in
163        some applications.
164    
165        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
166        so as not to refer to the tables, even though these functions will never be
167        called when UTF-8 support is disabled. Otherwise there are problems with a
168        shared library.
169    
170    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
171    
172        (a) It was defining its arguments as char * instead of void *.
173    
174        (b) It was assuming that all moves were upwards in memory; this was true
175            a long time ago when I wrote it, but is no longer the case.
176    
177        The emulated memove() is provided for those environments that have neither
178        memmove() nor bcopy(). I didn't think anyone used it these days, but that
179        is clearly not the case, as these two bugs were recently reported.
180    
181    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
182        and Detrail to create the HTML documentation, the .txt form of the man
183        pages, and it removes trailing spaces from listed files. It also creates
184        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
185        case, it wraps all the #defines with #ifndefs. This script should be run
186        before "make dist".
187    
188    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
189        with Unicode property support.
190    
191        (a) For a maximizing quantifier, if the two different cases of the
192            character were of different lengths in their UTF-8 codings (there are
193            some cases like this - I found 11), and the matching function had to
194            back up over a mixture of the two cases, it incorrectly assumed they
195            were both the same length.
196    
197        (b) When PCRE was configured to use the heap rather than the stack for
198            recursion during matching, it was not correctly preserving the data for
199            the other case of a UTF-8 character when checking ahead for a match
200            while processing a minimizing repeat. If the check also involved
201            matching a wide character, but failed, corruption could cause an
202            erroneous result when trying to check for a repeat of the original
203            character.
204    
205    13. Some tidying changes to the testing mechanism:
206    
207        (a) The RunTest script now detects the internal link size and whether there
208            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
209            values substituted by "configure". (The RunGrepTest script already did
210            this for UTF-8.) The configure.ac script no longer substitutes the
211            relevant variables.
212    
213        (b) The debugging options /B and /D in pcretest show the compiled bytecode
214            with length and offset values. This means that the output is different
215            for different internal link sizes. Test 2 is skipped for link sizes
216            other than 2 because of this, bypassing the problem. Unfortunately,
217            there was also a test in test 3 (the locale tests) that used /B and
218            failed for link sizes other than 2. Rather than cut the whole test out,
219            I have added a new /Z option to pcretest that replaces the length and
220            offset values with spaces. This is now used to make test 3 independent
221            of link size. (Test 2 will be tidied up later.)
222    
223    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
224        segmentation fault instead of returning the appropriate error message.
225    
226    15. In multiline mode when the newline sequence was set to "any", the pattern
227        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
228        This doesn't seem right; it now treats the CRLF combination as the line
229        ending, and so does not match in that case. It's only a pattern such as ^$
230        that would hit this one: something like ^ABC$ would have failed after \r
231        and then tried again after \r\n.
232    
233    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
234        in an attempt to make files that differ only in their line terminators
235        compare equal. This works on Linux.
236    
237    17. Under certain error circumstances pcregrep might try to free random memory
238        as it exited. This is now fixed, thanks to valgrind.
239    
240    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
241        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
242        was because its rules for how to advance for /g after matching an empty
243        string at the end of a line did not allow for this case. They now check for
244        it specially.
245    
246    20. pcretest is supposed to handle patterns and data of any length, by
247        extending its buffers when necessary. It was getting this wrong when the
248        buffer for a data line had to be extended.
249    
250    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
251        CRLF as a newline sequence.
252    
253    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
254        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
255        I have nevertheless tidied it up.
256    
257    23. Added some casts to kill warnings from HP-UX ia64 compiler.
258    
259    24. Added a man page for pcre-config.
260    
261    
262    Version 7.0 19-Dec-06
263    ---------------------
264    
265     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
266        moving to gcc 4.1.1.
267    
268     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
269        sys/time.h, which is documented as needed for this function. It doesn't
270        seem to matter on Linux, but it showed up on some releases of OS X.
271    
272     3. It seems that there are systems where bytes whose values are greater than
273        127 match isprint() in the "C" locale. The "C" locale should be the
274        default when a C program starts up. In most systems, only ASCII printing
275        characters match isprint(). This difference caused the output from pcretest
276        to vary, making some of the tests fail. I have changed pcretest so that:
277    
278        (a) When it is outputting text in the compiled version of a pattern, bytes
279            other than 32-126 are always shown as hex escapes.
280    
281        (b) When it is outputting text that is a matched part of a subject string,
282            it does the same, unless a different locale has been set for the match
283            (using the /L modifier). In this case, it uses isprint() to decide.
284    
285     4. Fixed a major bug that caused incorrect computation of the amount of memory
286        required for a compiled pattern when options that changed within the
287        pattern affected the logic of the preliminary scan that determines the
288        length. The relevant options are -x, and -i in UTF-8 mode. The result was
289        that the computed length was too small. The symptoms of this bug were
290        either the PCRE error "internal error: code overflow" from pcre_compile(),
291        or a glibc crash with a message such as "pcretest: free(): invalid next
292        size (fast)". Examples of patterns that provoked this bug (shown in
293        pcretest format) are:
294    
295          /(?-x: )/x
296          /(?x)(?-x: \s*#\s*)/
297          /((?i)[\x{c0}])/8
298          /(?i:[\x{c0}])/8
299    
300        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
301        is now done differently.
302    
303     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
304        wrapper classes; (b) implement a new function in the C++ scanner that is
305        more efficient than the old way of doing things because it avoids levels of
306        recursion in the regex matching; (c) add a paragraph to the documentation
307        for the FullMatch() function.
308    
309     6. The escape sequence \n was being treated as whatever was defined as
310        "newline". Not only was this contrary to the documentation, which states
311        that \n is character 10 (hex 0A), but it also went horribly wrong when
312        "newline" was defined as CRLF. This has been fixed.
313    
314     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
315        was being set to -1 for the "end of line" case (supposedly a value that no
316        character can have). Though this value is never used (the check for end of
317        line is "zero bytes in current character"), it caused compiler complaints.
318        I've changed it to 0xffffffff.
319    
320     8. In pcre_version.c, the version string was being built by a sequence of
321        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
322        string (as it is for production releases) called a macro with an empty
323        argument. The C standard says the result of this is undefined. The gcc
324        compiler treats it as an empty string (which was what was wanted) but it is
325        reported that Visual C gives an error. The source has been hacked around to
326        avoid this problem.
327    
328     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
329        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
330        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
331        of them did).
332    
333    10. Originally, pcretest opened its input and output without "b"; then I was
334        told that "b" was needed in some environments, so it was added for release
335        5.0 to both the input and output. (It makes no difference on Unix-like
336        systems.) Later I was told that it is wrong for the input on Windows. I've
337        now abstracted the modes into two macros, to make it easier to fiddle with
338        them, and removed "b" from the input mode under Windows.
339    
340    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
341    
342    12. Added -help and --help to pcretest as an official way of being reminded
343        of the options.
344    
345    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
346        and pcrecpp.cc because they annoy compilers at high warning levels.
347    
348    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
349    
350    15. Fixed an occurrence of == in configure.ac that should have been = (shell
351        scripts are not C programs :-) and which was not noticed because it works
352        on Linux.
353    
354    16. pcretest is supposed to handle any length of pattern and data line (as one
355        line or as a continued sequence of lines) by extending its input buffer if
356        necessary. This feature was broken for very long pattern lines, leading to
357        a string of junk being passed to pcre_compile() if the pattern was longer
358        than about 50K.
359    
360    17. I have done a major re-factoring of the way pcre_compile() computes the
361        amount of memory needed for a compiled pattern. Previously, there was code
362        that made a preliminary scan of the pattern in order to do this. That was
363        OK when PCRE was new, but as the facilities have expanded, it has become
364        harder and harder to keep it in step with the real compile phase, and there
365        have been a number of bugs (see for example, 4 above). I have now found a
366        cunning way of running the real compile function in a "fake" mode that
367        enables it to compute how much memory it would need, while actually only
368        ever using a few hundred bytes of working memory and without too many
369        tests of the mode. This should make future maintenance and development
370        easier. A side effect of this work is that the limit of 200 on the nesting
371        depth of parentheses has been removed (though this was never a serious
372        limitation, I suspect). However, there is a downside: pcre_compile() now
373        runs more slowly than before (30% or more, depending on the pattern). I
374        hope this isn't a big issue. There is no effect on runtime performance.
375    
376    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
377        newline (only possible for the last line of a file) and it was a
378        pattern that set a locale (followed by /Lsomething), pcretest crashed.
379    
380    19. Added additional timing features to pcretest. (1) The -tm option now times
381        matching only, not compiling. (2) Both -t and -tm can be followed, as a
382        separate command line item, by a number that specifies the number of
383        repeats to use when timing. The default is 50000; this gives better
384        precision, but takes uncomfortably long for very large patterns.
385    
386    20. Extended pcre_study() to be more clever in cases where a branch of a
387        subpattern has no definite first character. For example, (a*|b*)[cd] would
388        previously give no result from pcre_study(). Now it recognizes that the
389        first character must be a, b, c, or d.
390    
391    21. There was an incorrect error "recursive call could loop indefinitely" if
392        a subpattern (or the entire pattern) that was being tested for matching an
393        empty string contained only one non-empty item after a nested subpattern.
394        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
395        incorrectly, because the \d was being skipped in the check.
396    
397    22. The pcretest program now has a new pattern option /B and a command line
398        option -b, which is equivalent to adding /B to every pattern. This causes
399        it to show the compiled bytecode, without the additional information that
400        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
401        is the same as /B/I).
402    
403    23. A new optimization is now able automatically to treat some sequences such
404        as a*b as a*+b. More specifically, if something simple (such as a character
405        or a simple class like \d) has an unlimited quantifier, and is followed by
406        something that cannot possibly match the quantified thing, the quantifier
407        is automatically "possessified".
408    
409    24. A recursive reference to a subpattern whose number was greater than 39
410        went wrong under certain circumstances in UTF-8 mode. This bug could also
411        have affected the operation of pcre_study().
412    
413    25. Realized that a little bit of performance could be had by replacing
414        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
415    
416    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
417    
418    27. Possessive quantifiers such as a++ were previously implemented by turning
419        them into atomic groups such as ($>a+). Now they have their own opcodes,
420        which improves performance. This includes the automatically created ones
421        from 23 above.
422    
423    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
424        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
425        the first matched character to be a colon. This applied both to named and
426        numbered groups.
427    
428    29. The ucpinternal.h header file was missing its idempotency #ifdef.
429    
430    30. I was sent a "project" file called libpcre.a.dev which I understand makes
431        building PCRE on Windows easier, so I have included it in the distribution.
432    
433    31. There is now a check in pcretest against a ridiculously large number being
434        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
435        loop, the loop is abandoned.
436    
437    32. Forward references to subpatterns in conditions such as (?(2)...) where
438        subpattern 2 is defined later cause pcre_compile() to search forwards in
439        the pattern for the relevant set of parentheses. This search went wrong
440        when there were unescaped parentheses in a character class, parentheses
441        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
442    
443    33. "Subroutine" calls and backreferences were previously restricted to
444        referencing subpatterns earlier in the regex. This restriction has now
445        been removed.
446    
447    34. Added a number of extra features that are going to be in Perl 5.10. On the
448        whole, these are just syntactic alternatives for features that PCRE had
449        previously implemented using the Python syntax or my own invention. The
450        other formats are all retained for compatibility.
451    
452        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
453            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
454            also .NET compatible.
455    
456        (b) A recursion or subroutine call to a named group can now be defined as
457            (?&name) as well as (?P>name).
458    
459        (c) A backreference to a named group can now be defined as \k<name> or
460            \k'name' as well as (?P=name). The new forms, as well as being in Perl
461            5.10, are also .NET compatible.
462    
463        (d) A conditional reference to a named group can now use the syntax
464            (?(<name>) or (?('name') as well as (?(name).
465    
466        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
467            groups (named and numbered) that are never evaluated inline, but can be
468            called as "subroutines" from elsewhere. In effect, the DEFINE condition
469            is always false. There may be only one alternative in such a group.
470    
471        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
472            as the simple (?(R). The condition is true only if the most recent
473            recursion is that of the given number or name. It does not search out
474            through the entire recursion stack.
475    
476        (g) The escape \gN or \g{N} has been added, where N is a positive or
477            negative number, specifying an absolute or relative reference.
478    
479    35. Tidied to get rid of some further signed/unsigned compiler warnings and
480        some "unreachable code" warnings.
481    
482    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
483        things, this adds five new scripts.
484    
485    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
486        There were also incompatibilities regarding the handling of \Q..\E inside
487        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
488        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
489    
490    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
491        matches an empty string, and forcibly breaks the loop. There were bugs in
492        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
493        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
494        separate and independent bugs (that affected different cases) have been
495        fixed.
496    
497    39. Refactored the code to abolish the use of different opcodes for small
498        capturing bracket numbers. This is a tidy that I avoided doing when I
499        removed the limit on the number of capturing brackets for 3.5 back in 2001.
500        The new approach is not only tidier, it makes it possible to reduce the
501        memory needed to fix the previous bug (38).
502    
503    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
504        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
505        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
506        mode.
507    
508    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
509        report.
510    
511    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
512        copy construction and assignment in the C++ wrapper.
513    
514    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
515        couple of bugs that could have given wrong results in the "--newline=crlf"
516        case.
517    
518    44. Added a number of casts and did some reorganization of signed/unsigned int
519        variables following suggestions from Dair Grant. Also renamed the variable
520        "this" as "item" because it is a C++ keyword.
521    
522    45. Arranged for dftables to add
523    
524          #include "pcre_internal.h"
525    
526        to pcre_chartables.c because without it, gcc 4.x may remove the array
527        definition from the final binary if PCRE is built into a static library and
528        dead code stripping is activated.
529    
530    46. For an unanchored pattern, if a match attempt fails at the start of a
531        newline sequence, and the newline setting is CRLF or ANY, and the next two
532        characters are CRLF, advance by two characters instead of one.
533    
534    
535    Version 6.7 04-Jul-06
536    ---------------------
537    
538     1. In order to handle tests when input lines are enormously long, pcretest has
539        been re-factored so that it automatically extends its buffers when
540        necessary. The code is crude, but this _is_ just a test program. The
541        default size has been increased from 32K to 50K.
542    
543     2. The code in pcre_study() was using the value of the re argument before
544        testing it for NULL. (Of course, in any sensible call of the function, it
545        won't be NULL.)
546    
547     3. The memmove() emulation function in pcre_internal.h, which is used on
548        systems that lack both memmove() and bcopy() - that is, hardly ever -
549        was missing a "static" storage class specifier.
550    
551     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
552        containing an extended class (one that cannot be represented by a bitmap
553        because it contains high-valued characters or Unicode property items, e.g.
554        [\pZ]). Almost always one would set UTF-8 mode when processing such a
555        pattern, but PCRE should not loop if you do not (it no longer does).
556        [Detail: two cases were found: (a) a repeated subpattern containing an
557        extended class; (b) a recursive reference to a subpattern that followed a
558        previous extended class. It wasn't skipping over the extended class
559        correctly when UTF-8 mode was not set.]
560    
561     5. A negated single-character class was not being recognized as fixed-length
562        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
563        compile error "lookbehind assertion is not fixed length".
564    
565     6. The RunPerlTest auxiliary script was showing an unexpected difference
566        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
567        write a Perl script that can interpret lines of an input file either as
568        byte characters or as UTF-8, which is what "perltest" was being required to
569        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
570        can't do is switch easily at run time between having the "use utf8;" pragma
571        or not. In the end, I fudged it by using the RunPerlTest script to insert
572        "use utf8;" explicitly for the UTF-8 tests.
573    
574     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
575        the end of the subject string, contrary to the documentation and to what
576        Perl does. This was true of both matching functions. Now it matches only at
577        the start of the subject and immediately after *internal* newlines.
578    
579     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
580        a pointer to an int instead of a pointer to an unsigned long int. This
581        caused problems on 64-bit systems.
582    
583     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
584        instance of the 'standard' template library not being so standard".
585    
586    10. There was no check on the number of named subpatterns nor the maximum
587        length of a subpattern name. The product of these values is used to compute
588        the size of the memory block for a compiled pattern. By supplying a very
589        long subpattern name and a large number of named subpatterns, the size
590        computation could be caused to overflow. This is now prevented by limiting
591        the length of names to 32 characters, and the number of named subpatterns
592        to 10,000.
593    
594    11. Subpatterns that are repeated with specific counts have to be replicated in
595        the compiled pattern. The size of memory for this was computed from the
596        length of the subpattern and the repeat count. The latter is limited to
597        65535, but there was no limit on the former, meaning that integer overflow
598        could in principle occur. The compiled length of a repeated subpattern is
599        now limited to 30,000 bytes in order to prevent this.
600    
601    12. Added the optional facility to have named substrings with the same name.
602    
603    13. Added the ability to use a named substring as a condition, using the
604        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
605        are numbers (not recommended). Forward references are permitted.
606    
607    14. Added forward references in named backreferences (if you see what I mean).
608    
609    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
610        pattern could run off the end of the subject. For example, the pattern
611        "(?s)(.{1,5})"8 did this with the subject "ab".
612    
613    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
614        PCRE_CASELESS was set when matching characters that were quantified with ?
615        or *.
616    
617    17. A character class other than a single negated character that had a minimum
618        but no maximum quantifier - for example [ab]{6,} - was not handled
619        correctly by pce_dfa_exec(). It would match only one character.
620    
621    18. A valid (though odd) pattern that looked like a POSIX character
622        class but used an invalid character after [ (for example [[,abc,]]) caused
623        pcre_compile() to give the error "Failed: internal error: code overflow" or
624        in some cases to crash with a glibc free() error. This could even happen if
625        the pattern terminated after [[ but there just happened to be a sequence of
626        letters, a binary zero, and a closing ] in the memory that followed.
627    
628    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
629        over the years. Originally (before any Unicode support), just the bottom 8
630        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
631        output from "man perlunicode" includes this:
632    
633          The regular expression compiler produces polymorphic opcodes.  That
634          is, the pattern adapts to the data and automatically switches to
635          the Unicode character scheme when presented with Unicode data--or
636          instead uses a traditional byte scheme when presented with byte
637          data.
638    
639        Sadly, a wide octal escape does not cause a switch, and in a string with
640        no other multibyte characters, these octal escapes are treated as before.
641        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
642        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
643        Unicode string.
644    
645        I have not perpetrated such confusion in PCRE. Up till now, it took just
646        the bottom 8 bits, as in old Perl. I have now made octal escapes with
647        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
648        translate to the appropriate multibyte character.
649    
650    29. Applied some refactoring to reduce the number of warnings from Microsoft
651        and Borland compilers. This has included removing the fudge introduced
652        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
653        a warning about an unused variable.
654    
655    21. PCRE has not included VT (character 0x0b) in the set of whitespace
656        characters since release 4.0, because Perl (from release 5.004) does not.
657        [Or at least, is documented not to: some releases seem to be in conflict
658        with the documentation.] However, when a pattern was studied with
659        pcre_study() and all its branches started with \s, PCRE still included VT
660        as a possible starting character. Of course, this did no harm; it just
661        caused an unnecessary match attempt.
662    
663    22. Removed a now-redundant internal flag bit that recorded the fact that case
664        dependency changed within the pattern. This was once needed for "required
665        byte" processing, but is no longer used. This recovers a now-scarce options
666        bit. Also moved the least significant internal flag bit to the most-
667        significant bit of the word, which was not previously used (hangover from
668        the days when it was an int rather than a uint) to free up another bit for
669        the future.
670    
671    23. Added support for CRLF line endings as well as CR and LF. As well as the
672        default being selectable at build time, it can now be changed at runtime
673        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
674        specify that it is scanning data with non-default line endings.
675    
676    24. Changed the definition of CXXLINK to make it agree with the definition of
677        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
678    
679    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
680        recursions. This makes a big different to stack usage for some patterns.
681    
682    26. If a subpattern containing a named recursion or subroutine reference such
683        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
684        the space required for the compiled pattern went wrong and gave too small a
685        value. Depending on the environment, this could lead to "Failed: internal
686        error: code overflow at offset 49" or "glibc detected double free or
687        corruption" errors.
688    
689    27. Applied patches from Google (a) to support the new newline modes and (b) to
690        advance over multibyte UTF-8 characters in GlobalReplace.
691    
692    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
693        difference for some implementation of PCRE in some Windows version.
694    
695    29. Added some extra testing facilities to pcretest:
696    
697        \q<number>   in a data line sets the "match limit" value
698        \Q<number>   in a data line sets the "match recursion limt" value
699        -S <number>  sets the stack size, where <number> is in megabytes
700    
701        The -S option isn't available for Windows.
702    
703    
704    Version 6.6 06-Feb-06
705    ---------------------
706    
707     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
708        in pcreposix.h. I have copied the definition from pcre.h.
709    
710     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
711        because pcre.h is no longer a built file.
712    
713     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
714        not normally included in the compiled code.
715    
716    
717    Version 6.5 01-Feb-06
718    ---------------------
719    
720     1. When using the partial match feature with pcre_dfa_exec(), it was not
721        anchoring the second and subsequent partial matches at the new starting
722        point. This could lead to incorrect results. For example, with the pattern
723        /1234/, partially matching against "123" and then "a4" gave a match.
724    
725     2. Changes to pcregrep:
726    
727        (a) All non-match returns from pcre_exec() were being treated as failures
728            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
729            error message is output. Some extra information is given for the
730            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
731            probably the only errors that are likely to be caused by users (by
732            specifying a regex that has nested indefinite repeats, for instance).
733            If there are more than 20 of these errors, pcregrep is abandoned.
734    
735        (b) A binary zero was treated as data while matching, but terminated the
736            output line if it was written out. This has been fixed: binary zeroes
737            are now no different to any other data bytes.
738    
739        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
740            used to set a locale for matching. The --locale=xxxx long option has
741            been added (no short equivalent) to specify a locale explicitly on the
742            pcregrep command, overriding the environment variables.
743    
744        (d) When -B was used with -n, some line numbers in the output were one less
745            than they should have been.
746    
747        (e) Added the -o (--only-matching) option.
748    
749        (f) If -A or -C was used with -c (count only), some lines of context were
750            accidentally printed for the final match.
751    
752        (g) Added the -H (--with-filename) option.
753    
754        (h) The combination of options -rh failed to suppress file names for files
755            that were found from directory arguments.
756    
757        (i) Added the -D (--devices) and -d (--directories) options.
758    
759        (j) Added the -F (--fixed-strings) option.
760    
761        (k) Allow "-" to be used as a file name for -f as well as for a data file.
762    
763        (l) Added the --colo(u)r option.
764    
765        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
766            is not present by default.
767    
768     3. A nasty bug was discovered in the handling of recursive patterns, that is,
769        items such as (?R) or (?1), when the recursion could match a number of
770        alternatives. If it matched one of the alternatives, but subsequently,
771        outside the recursion, there was a failure, the code tried to back up into
772        the recursion. However, because of the way PCRE is implemented, this is not
773        possible, and the result was an incorrect result from the match.
774    
775        In order to prevent this happening, the specification of recursion has
776        been changed so that all such subpatterns are automatically treated as
777        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
778    
779     4. I had overlooked the fact that, in some locales, there are characters for
780        which isalpha() is true but neither isupper() nor islower() are true. In
781        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
782        and ordfeminine) are like this. This affected the treatment of \w and \W
783        when they appeared in character classes, but not when they appeared outside
784        a character class. The bit map for "word" characters is now created
785        separately from the results of isalnum() instead of just taking it from the
786        upper, lower, and digit maps. (Plus the underscore character, of course.)
787    
788     5. The above bug also affected the handling of POSIX character classes such as
789        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
790        permanent tables. Instead, the bit maps for such a class were previously
791        created as the appropriate unions of the upper, lower, and digit bitmaps.
792        Now they are created by subtraction from the [[:word:]] class, which has
793        its own bitmap.
794    
795     6. The [[:blank:]] character class matches horizontal, but not vertical space.
796        It is created by subtracting the vertical space characters (\x09, \x0a,
797        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
798        subtraction was done in the overall bitmap for a character class, meaning
799        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
800        be recognized. This bug has been fixed.
801    
802     7. Patches from the folks at Google:
803    
804          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
805          real life, but is still worth protecting against".
806    
807          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
808          regular expressions".
809    
810          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
811          have it.
812    
813          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
814          "configure" and the latter not, in order to fix a problem somebody had
815          with compiling the Arg class on HP-UX.
816    
817          (e) Improve the error-handling of the C++ wrapper a little bit.
818    
819          (f) New tests for checking recursion limiting.
820    
821     8. The pcre_memmove() function, which is used only if the environment does not
822        have a standard memmove() function (and is therefore rarely compiled),
823        contained two bugs: (a) use of int instead of size_t, and (b) it was not
824        returning a result (though PCRE never actually uses the result).
825    
826     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
827        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
828        returned instead of calling malloc() with an overflowing number that would
829        most likely cause subsequent chaos.
830    
831    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
832    
833    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
834        with this option is matched, the nmatch and pmatch options of regexec() are
835        ignored.
836    
837    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
838        provided in case anyone wants to the the POSIX interface with UTF-8
839        strings.
840    
841    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
842        C++ linking (needed for some HP-UX environments).
843    
844    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
845        (unused parameter) and in the pcre_printint() function (omitted "default"
846        switch label when the default is to do nothing).
847    
848    15. Added some code to make it possible, when PCRE is compiled as a C++
849        library, to replace subject pointers for pcre_exec() with a smart pointer
850        class, thus making it possible to process discontinuous strings.
851    
852    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
853        much the same function. They were added by different people who were trying
854        to make PCRE easy to compile on non-Unix systems. It has been suggested
855        that PCRE_EXPORT be abolished now that there is more automatic apparatus
856        for compiling on Windows systems. I have therefore replaced it with
857        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
858        defaults to "extern" for C or "extern C" for C++, which works fine on
859        Unix-like systems. It is now possible to override the value of PCRE_DATA_
860        SCOPE with something explicit in config.h. In addition:
861    
862        (a) pcreposix.h still had just "extern" instead of either of these macros;
863            I have replaced it with PCRE_DATA_SCOPE.
864    
865        (b) Functions such as _pcre_xclass(), which are internal to the library,
866            but external in the C sense, all had PCRE_EXPORT in their definitions.
867            This is apparently wrong for the Windows case, so I have removed it.
868            (It makes no difference on Unix-like systems.)
869    
870    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
871        of recursive calls to match(). This is different to MATCH_LIMIT because
872        that limits the total number of calls to match(), not all of which increase
873        the depth of recursion. Limiting the recursion depth limits the amount of
874        stack (or heap if NO_RECURSE is set) that is used. The default can be set
875        when PCRE is compiled, and changed at run time. A patch from Google adds
876        this functionality to the C++ interface.
877    
878    18. Changes to the handling of Unicode character properties:
879    
880        (a) Updated the table to Unicode 4.1.0.
881    
882        (b) Recognize characters that are not in the table as "Cn" (undefined).
883    
884        (c) I revised the way the table is implemented to a much improved format
885            which includes recognition of ranges. It now supports the ranges that
886            are defined in UnicodeData.txt, and it also amalgamates other
887            characters into ranges. This has reduced the number of entries in the
888            table from around 16,000 to around 3,000, thus reducing its size
889            considerably. I realized I did not need to use a tree structure after
890            all - a binary chop search is just as efficient. Having reduced the
891            number of entries, I extended their size from 6 bytes to 8 bytes to
892            allow for more data.
893    
894        (d) Added support for Unicode script names via properties such as \p{Han}.
895    
896    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
897        matching that character.
898    
899    20. When matching a repeated Unicode property with a minimum greater than zero,
900        (for example \pL{2,}), PCRE could look past the end of the subject if it
901        reached it while seeking the minimum number of characters. This could
902        happen only if some of the characters were more than one byte long, because
903        there is a check for at least the minimum number of bytes.
904    
905    21. Refactored the implementation of \p and \P so as to be more general, to
906        allow for more different types of property in future. This has changed the
907        compiled form incompatibly. Anybody with saved compiled patterns that use
908        \p or \P will have to recompile them.
909    
910    22. Added "Any" and "L&" to the supported property types.
911    
912    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
913        but give a compile time error if the value is greater than 0xff.
914    
915    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
916        accidentally not being installed or uninstalled.
917    
918    25. The pcre.h file was built from pcre.h.in, but the only changes that were
919        made were to insert the current release number. This seemed silly, because
920        it made things harder for people building PCRE on systems that don't run
921        "configure". I have turned pcre.h into a distributed file, no longer built
922        by "configure", with the version identification directly included. There is
923        no longer a pcre.h.in file.
924    
925        However, this change necessitated a change to the pcre-config script as
926        well. It is built from pcre-config.in, and one of the substitutions was the
927        release number. I have updated configure.ac so that ./configure now finds
928        the release number by grepping pcre.h.
929    
930    26. Added the ability to run the tests under valgrind.
931    
932    
933    Version 6.4 05-Sep-05
934    ---------------------
935    
936     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
937        "--" to be printed when multiple files were scanned, even when none of the
938        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
939        consider it to be a bug, and have restored the previous behaviour.
940    
941     2. A couple of code tidies to get rid of compiler warnings.
942    
943     3. The pcretest program used to cheat by referring to symbols in the library
944        whose names begin with _pcre_. These are internal symbols that are not
945        really supposed to be visible externally, and in some environments it is
946        possible to suppress them. The cheating is now confined to including
947        certain files from the library's source, which is a bit cleaner.
948    
949     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
950        file's purpose clearer.
951    
952     5. Reorganized pcre_ucp_findchar().
953    
954    
955    Version 6.3 15-Aug-05
956    ---------------------
957    
958     1. The file libpcre.pc.in did not have general read permission in the tarball.
959    
960     2. There were some problems when building without C++ support:
961    
962        (a) If C++ support was not built, "make install" and "make test" still
963            tried to test it.
964    
965        (b) There were problems when the value of CXX was explicitly set. Some
966            changes have been made to try to fix these, and ...
967    
968        (c) --disable-cpp can now be used to explicitly disable C++ support.
969    
970        (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
971            backslash in a target when C++ was disabled. This confuses some
972            versions of "make", apparently. Using an intermediate variable solves
973            this. (Same for CPP_LOBJ.)
974    
975     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
976        (non-Windows) now includes $(CFLAGS) because these flags are sometimes
977        necessary on certain architectures.
978    
979     4. Added a setting of -export-symbols-regex to the link command to remove
980        those symbols that are exported in the C sense, but actually are local
981        within the library, and not documented. Their names all begin with
982        "_pcre_". This is not a perfect job, because (a) we have to except some
983        symbols that pcretest ("illegally") uses, and (b) the facility isn't always
984        available (and never for static libraries). I have made a note to try to
985        find a way round (a) in the future.
986    
987    
988    Version 6.2 01-Aug-05
989    ---------------------
990    
991     1. There was no test for integer overflow of quantifier values. A construction
992        such as {1111111111111111} would give undefined results. What is worse, if
993        a minimum quantifier for a parenthesized subpattern overflowed and became
994        negative, the calculation of the memory size went wrong. This could have
995        led to memory overwriting.
996    
997     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
998    
999     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1000        operating environments where this matters.
1001    
1002     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1003        PCRE options from within the C++ wrapper.
1004    
1005     5. Named capturing subpatterns were not being correctly counted when a pattern
1006        was compiled. This caused two problems: (a) If there were more than 100
1007        such subpatterns, the calculation of the memory needed for the whole
1008        compiled pattern went wrong, leading to an overflow error. (b) Numerical
1009        back references of the form \12, where the number was greater than 9, were
1010        not recognized as back references, even though there were sufficient
1011        previous subpatterns.
1012    
1013     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1014        versions of gcc, e.g. 2.95.4.
1015    
1016    
1017    Version 6.1 21-Jun-05
1018    ---------------------
1019    
1020     1. There was one reference to the variable "posix" in pcretest.c that was not
1021        surrounded by "#if !defined NOPOSIX".
1022    
1023     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1024        the cross-check on the old pcre_info() function, for the benefit of the
1025        cut-down version of PCRE that is currently imported into Exim.
1026    
1027     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1028        allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1029        patterns that start (?i) but I don't think that matters. The use of (?i) is
1030        just an example; this all applies to the other options as well.
1031    
1032     4. Since libtool seems to echo the compile commands it is issuing, the output
1033        from "make" can be reduced a bit by putting "@" in front of each libtool
1034        compile command.
1035    
1036     5. Patch from the folks at Google for configure.in to be a bit more thorough
1037        in checking for a suitable C++ installation before trying to compile the
1038        C++ stuff. This should fix a reported problem when a compiler was present,
1039        but no suitable headers.
1040    
1041     6. The man pages all had just "PCRE" as their title. I have changed them to
1042        be the relevant file name. I have also arranged that these names are
1043        retained in the file doc/pcre.txt, which is a concatenation in text format
1044        of all the man pages except the little individual ones for each function.
1045    
1046     7. The NON-UNIX-USE file had not been updated for the different set of source
1047        files that come with release 6. I also added a few comments about the C++
1048        wrapper.
1049    
1050    
1051    Version 6.0 07-Jun-05
1052    ---------------------
1053    
1054     1. Some minor internal re-organization to help with my DFA experiments.
1055    
1056     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1057        didn't matter for the library itself when fully configured, but did matter
1058        when compiling without UCP support, or within Exim, where the ucp files are
1059        not imported.
1060    
1061     3. Refactoring of the library code to split up the various functions into
1062        different source modules. The addition of the new DFA matching code (see
1063        below) to a single monolithic source would have made it really too
1064        unwieldy, quite apart from causing all the code to be include in a
1065        statically linked application, when only some functions are used. This is
1066        relevant even without the DFA addition now that patterns can be compiled in
1067        one application and matched in another.
1068    
1069        The downside of splitting up is that there have to be some external
1070        functions and data tables that are used internally in different modules of
1071        the library but which are not part of the API. These have all had their
1072        names changed to start with "_pcre_" so that they are unlikely to clash
1073        with other external names.
1074    
1075     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1076        a different (DFA) algorithm. Although it is slower than the original
1077        function, it does have some advantages for certain types of matching
1078        problem.
1079    
1080     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1081        including restarting after a partial match.
1082    
1083     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1084        defined when compiling for Windows was sent to me. I have put it into the
1085        code, though I have no means of testing or verifying it.
1086    
1087     7. Added the pcre_refcount() auxiliary function.
1088    
1089     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1090        match before or at the first newline in the subject string. In pcretest,
1091        the /f option on a pattern can be used to set this.
1092    
1093     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1094        would behave wrongly. This has been present in PCRE since release 4.0.
1095    
1096    10. A number of changes to the pcregrep command:
1097    
1098        (a) Refactored how -x works; insert ^(...)$ instead of setting
1099            PCRE_ANCHORED and checking the length, in preparation for adding
1100            something similar for -w.
1101    
1102        (b) Added the -w (match as a word) option.
1103    
1104        (c) Refactored the way lines are read and buffered so as to have more
1105            than one at a time available.
1106    
1107        (d) Implemented a pcregrep test script.
1108    
1109        (e) Added the -M (multiline match) option. This allows patterns to match
1110            over several lines of the subject. The buffering ensures that at least
1111            8K, or the rest of the document (whichever is the shorter) is available
1112            for matching (and similarly the previous 8K for lookbehind assertions).
1113    
1114        (f) Changed the --help output so that it now says
1115    
1116              -w, --word-regex(p)
1117    
1118            instead of two lines, one with "regex" and the other with "regexp"
1119            because that confused at least one person since the short forms are the
1120            same. (This required a bit of code, as the output is generated
1121            automatically from a table. It wasn't just a text change.)
1122    
1123        (g) -- can be used to terminate pcregrep options if the next thing isn't an
1124            option but starts with a hyphen. Could be a pattern or a path name
1125            starting with a hyphen, for instance.
1126    
1127        (h) "-" can be given as a file name to represent stdin.
1128    
1129        (i) When file names are being printed, "(standard input)" is used for
1130            the standard input, for compatibility with GNU grep. Previously
1131            "<stdin>" was used.
1132    
1133        (j) The option --label=xxx can be used to supply a name to be used for
1134            stdin when file names are being printed. There is no short form.
1135    
1136        (k) Re-factored the options decoding logic because we are going to add
1137            two more options that take data. Such options can now be given in four
1138            different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1139    
1140        (l) Added the -A, -B, and -C options for requesting that lines of context
1141            around matches be printed.
1142    
1143        (m) Added the -L option to print the names of files that do not contain
1144            any matching lines, that is, the complement of -l.
1145    
1146        (n) The return code is 2 if any file cannot be opened, but pcregrep does
1147            continue to scan other files.
1148    
1149        (o) The -s option was incorrectly implemented. For compatibility with other
1150            greps, it now suppresses the error message for a non-existent or non-
1151            accessible file (but not the return code). There is a new option called
1152            -q that suppresses the output of matching lines, which was what -s was
1153            previously doing.
1154    
1155        (p) Added --include and --exclude options to specify files for inclusion
1156            and exclusion when recursing.
1157    
1158    11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1159        Hopefully, it now does.
1160    
1161    12. Missing cast in pcre_study().
1162    
1163    13. Added an "uninstall" target to the makefile.
1164    
1165    14. Replaced "extern" in the function prototypes in Makefile.in with
1166        "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1167        world, but is set differently for Windows.
1168    
1169    15. Added a second compiling function called pcre_compile2(). The only
1170        difference is that it has an extra argument, which is a pointer to an
1171        integer error code. When there is a compile-time failure, this is set
1172        non-zero, in addition to the error test pointer being set to point to an
1173        error message. The new argument may be NULL if no error number is required
1174        (but then you may as well call pcre_compile(), which is now just a
1175        wrapper). This facility is provided because some applications need a
1176        numeric error indication, but it has also enabled me to tidy up the way
1177        compile-time errors are handled in the POSIX wrapper.
1178    
1179    16. Added VPATH=.libs to the makefile; this should help when building with one
1180        prefix path and installing with another. (Or so I'm told by someone who
1181        knows more about this stuff than I do.)
1182    
1183    17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1184        passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1185        match everything, including newlines. This is not POSIX-compatible, but
1186        somebody wanted the feature. From pcretest it can be activated by using
1187        both the P and the s flags.
1188    
1189    18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1190    
1191    19. libpcre.pc was being incorrectly installed as executable.
1192    
1193    20. A couple of places in pcretest check for end-of-line by looking for '\n';
1194        it now also looks for '\r' so that it will work unmodified on Windows.
1195    
1196    21. Added Google's contributed C++ wrapper to the distribution.
1197    
1198    22. Added some untidy missing memory free() calls in pcretest, to keep
1199        Electric Fence happy when testing.
1200    
1201    
1202    
1203    Version 5.0 13-Sep-04
1204    ---------------------
1205    
1206     1. Internal change: literal characters are no longer packed up into items
1207        containing multiple characters in a single byte-string. Each character
1208        is now matched using a separate opcode. However, there may be more than one
1209        byte in the character in UTF-8 mode.
1210    
1211     2. The pcre_callout_block structure has two new fields: pattern_position and
1212        next_item_length. These contain the offset in the pattern to the next match
1213        item, and its length, respectively.
1214    
1215     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1216        insertion of callouts before each pattern item. Added the /C option to
1217        pcretest to make use of this.
1218    
1219     4. On the advice of a Windows user, the lines
1220    
1221          #if defined(_WIN32) || defined(WIN32)
1222          _setmode( _fileno( stdout ), 0x8000 );
1223          #endif  /* defined(_WIN32) || defined(WIN32) */
1224    
1225        have been added to the source of pcretest. This apparently does useful
1226        magic in relation to line terminators.
1227    
1228     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1229        for the benefit of those environments where the "b" makes a difference.
1230    
1231     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1232        to know about it. I have put a hack into configure.in that adds in code
1233        to set GCC=yes if CC=icc. This seems to end up at a point in the
1234        generated configure script that is early enough to affect the setting of
1235        compiler options, which is what is needed, but I have no means of testing
1236        whether it really works. (The user who reported this had patched the
1237        generated configure script, which of course I cannot do.)
1238    
1239        LATER: After change 22 below (new libtool files), the configure script
1240        seems to know about icc (and also ecc). Therefore, I have commented out
1241        this hack in configure.in.
1242    
1243     7. Added support for pkg-config (2 patches were sent in).
1244    
1245     8. Negated POSIX character classes that used a combination of internal tables
1246        were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1247        [[:^ascii]]. Typically, they would match almost any characters. The other
1248        POSIX classes were not broken in this way.
1249    
1250     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1251        to find the match, as PCRE was deluded into thinking that the match had to
1252        start at the start point or following a newline. The same bug applied to
1253        patterns with negative forward assertions or any backward assertions
1254        preceding ".*" at the start, unless the pattern required a fixed first
1255        character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1256    
1257    10. In UTF-8 mode, when moving forwards in the subject after a failed match
1258        starting at the last subject character, bytes beyond the end of the subject
1259        string were read.
1260    
1261    11. Renamed the variable "class" as "classbits" to make life easier for C++
1262        users. (Previously there was a macro definition, but it apparently wasn't
1263        enough.)
1264    
1265    12. Added the new field "tables" to the extra data so that tables can be passed
1266        in at exec time, or the internal tables can be re-selected. This allows
1267        a compiled regex to be saved and re-used at a later time by a different
1268        program that might have everything at different addresses.
1269    
1270    13. Modified the pcre-config script so that, when run on Solaris, it shows a
1271        -R library as well as a -L library.
1272    
1273    14. The debugging options of pcretest (-d on the command line or D on a
1274        pattern) showed incorrect output for anything following an extended class
1275        that contained multibyte characters and which was followed by a quantifier.
1276    
1277    15. Added optional support for general category Unicode character properties
1278        via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1279        support. It adds about 90K to the size of the library. The meanings of the
1280        inbuilt class escapes such as \d and \s have NOT been changed.
1281    
1282    16. Updated pcredemo.c to include calls to free() to release the memory for the
1283        compiled pattern.
1284    
1285    17. The generated file chartables.c was being created in the source directory
1286        instead of in the building directory. This caused the build to fail if the
1287        source directory was different from the building directory, and was
1288        read-only.
1289    
1290    18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1291        file. No doubt somebody will tell me if they don't make sense... Also added
1292        Dan Mooney's comments about building on OpenVMS.
1293    
1294    19. Added support for partial matching via the PCRE_PARTIAL option for
1295        pcre_exec() and the \P data escape in pcretest.
1296    
1297    20. Extended pcretest with 3 new pattern features:
1298    
1299        (i)   A pattern option of the form ">rest-of-line" causes pcretest to
1300              write the compiled pattern to the file whose name is "rest-of-line".
1301              This is a straight binary dump of the data, with the saved pointer to
1302              the character tables forced to be NULL. The study data, if any, is
1303              written too. After writing, pcretest reads a new pattern.
1304    
1305        (ii)  If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1306              compiled pattern from the given file. There must not be any
1307              occurrences of "<" in the file name (pretty unlikely); if there are,
1308              pcretest will instead treat the initial "<" as a pattern delimiter.
1309              After reading in the pattern, pcretest goes on to read data lines as
1310              usual.
1311    
1312        (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1313              and 16-bit fields in a compiled pattern, to simulate a pattern that
1314              was compiled on a host of opposite endianness.
1315    
1316    21. The pcre-exec() function can now cope with patterns that were compiled on
1317        hosts of opposite endianness, with this restriction:
1318    
1319          As for any compiled expression that is saved and used later, the tables
1320          pointer field cannot be preserved; the extra_data field in the arguments
1321          to pcre_exec() should be used to pass in a tables address if a value
1322          other than the default internal tables were used at compile time.
1323    
1324    22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1325        now diagnosed as an error. Previously, most of the time, a negative number
1326        would have been treated as zero, but if in addition "ovector" was passed as
1327        NULL, a crash could occur.
1328    
1329    23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1330        new versions from the libtool 1.5 distribution (the last one is a copy of
1331        a file called libtool.m4). This seems to have fixed the need to patch
1332        "configure" to support Darwin 1.3 (which I used to do). However, I still
1333        had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1334        workstation).
1335    
1336    24. Changed the PCRE licence to be the more standard "BSD" licence.
1337    
1338    
1339    Version 4.5 01-Dec-03
1340    ---------------------
1341    
1342     1. There has been some re-arrangement of the code for the match() function so
1343        that it can be compiled in a version that does not call itself recursively.
1344        Instead, it keeps those local variables that need separate instances for
1345        each "recursion" in a frame on the heap, and gets/frees frames whenever it
1346        needs to "recurse". Keeping track of where control must go is done by means
1347        of setjmp/longjmp. The whole thing is implemented by a set of macros that
1348        hide most of the details from the main code, and operates only if
1349        NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1350        "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1351        operating.
1352    
1353        To make it easier for callers to provide specially tailored get/free
1354        functions for this usage, two new functions, pcre_stack_malloc, and
1355        pcre_stack_free, are used. They are always called in strict stacking order,
1356        and the size of block requested is always the same.
1357    
1358        The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1359        PCRE has been compiled to use the stack or the heap for recursion. The
1360        -C option of pcretest uses this to show which version is compiled.
1361    
1362        A new data escape \S, is added to pcretest; it causes the amounts of store
1363        obtained and freed by both kinds of malloc/free at match time to be added
1364        to the output.
1365    
1366     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1367        what's available on my current Linux desktop machine.
1368    
1369     3. When matching a UTF-8 string, the test for a valid string at the start has
1370        been extended. If start_offset is not zero, PCRE now checks that it points
1371        to a byte that is the start of a UTF-8 character. If not, it returns
1372        PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1373        this is necessary because there may be backward assertions in the pattern.
1374        When matching the same subject several times, it may save resources to use
1375        PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1376    
1377     4. The code for checking the validity of UTF-8 strings has been tightened so
1378        that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1379        containing "overlong sequences".
1380    
1381     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1382        I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1383        should have been "&", but it just so happened that all the cases this let
1384        through by mistake were picked up later in the function.
1385    
1386     6. I had used a variable called "isblank" - this is a C99 function, causing
1387        some compilers to warn. To avoid this, I renamed it (as "blankclass").
1388    
1389     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1390        prompting; (b) run "./pcretest /dev/null" at the start of the test script
1391        so the version is shown; (c) stop "make test" echoing "./RunTest".
1392    
1393     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1394    
1395     9. The prototype for memmove() for systems that don't have it was using
1396        size_t, but the inclusion of the header that defines size_t was later. I've
1397        moved the #includes for the C headers earlier to avoid this.
1398    
1399    10. Added some adjustments to the code to make it easier to compiler on certain
1400        special systems:
1401    
1402          (a) Some "const" qualifiers were missing.
1403          (b) Added the macro EXPORT before all exported functions; by default this
1404              is defined to be empty.
1405          (c) Changed the dftables auxiliary program (that builds chartables.c) so
1406              that it reads its output file name as an argument instead of writing
1407              to the standard output and assuming this can be redirected.
1408    
1409    11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1410        class containing characters with values greater than 255, PCRE compilation
1411        went into a loop.
1412    
1413    12. A recursive reference to a subpattern that was within another subpattern
1414        that had a minimum quantifier of zero caused PCRE to crash. For example,
1415        (x(y(?2))z)? provoked this bug with a subject that got as far as the
1416        recursion. If the recursively-called subpattern itself had a zero repeat,
1417        that was OK.
1418    
1419    13. In pcretest, the buffer for reading a data line was set at 30K, but the
1420        buffer into which it was copied (for escape processing) was still set at
1421        1024, so long lines caused crashes.
1422    
1423    14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1424        "internal error: code overflow...". This applied to any character class
1425        that was followed by a possessive quantifier.
1426    
1427    15. Modified the Makefile to add libpcre.la as a prerequisite for
1428        libpcreposix.la because I was told this is needed for a parallel build to
1429        work.
1430    
1431    16. If a pattern that contained .* following optional items at the start was
1432        studied, the wrong optimizing data was generated, leading to matching
1433        errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1434        matching string must start with a or b or c. The correct conclusion for
1435        this pattern is that a match can start with any character.
1436    
1437    
1438    Version 4.4 13-Aug-03
1439    ---------------------
1440    
1441     1. In UTF-8 mode, a character class containing characters with values between
1442        127 and 255 was not handled correctly if the compiled pattern was studied.
1443        In fixing this, I have also improved the studying algorithm for such
1444        classes (slightly).
1445    
1446     2. Three internal functions had redundant arguments passed to them. Removal
1447        might give a very teeny performance improvement.
1448    
1449     3. Documentation bug: the value of the capture_top field in a callout is *one
1450        more than* the number of the hightest numbered captured substring.
1451    
1452     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1453        in incorrectly linking with a previously installed version. They now link
1454        explicitly with libpcre.la.
1455    
1456     5. configure.in no longer needs to recognize Cygwin specially.
1457    
1458     6. A problem in pcre.in for Windows platforms is fixed.
1459    
1460     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1461        pcretest, it used to include the size of the study block as part of its
1462        output. Unfortunately, the structure contains a field that has a different
1463        size on different hardware architectures. This meant that the tests that
1464        showed this size failed. As the block is currently always of a fixed size,
1465        this information isn't actually particularly useful in pcretest output, so
1466        I have just removed it.
1467    
1468     8. Three pre-processor statements accidentally did not start in column 1.
1469        Sadly, there are *still* compilers around that complain, even though
1470        standard C has not required this for well over a decade. Sigh.
1471    
1472     9. In pcretest, the code for checking callouts passed small integers in the
1473        callout_data field, which is a void * field. However, some picky compilers
1474        complained about the casts involved for this on 64-bit systems. Now
1475        pcretest passes the address of the small integer instead, which should get
1476        rid of the warnings.
1477    
1478    10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1479        both compile and run time, and gives an error if an invalid UTF-8 sequence
1480        is found. There is a option for disabling this check in cases where the
1481        string is known to be correct and/or the maximum performance is wanted.
1482    
1483    11. In response to a bug report, I changed one line in Makefile.in from
1484    
1485            -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1486        to
1487            -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1488    
1489        to look similar to other lines, but I have no way of telling whether this
1490        is the right thing to do, as I do not use Windows. No doubt I'll get told
1491        if it's wrong...
1492    
1493    
1494    Version 4.3 21-May-03
1495    ---------------------
1496    
1497    1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1498       Makefile.
1499    
1500    2. Some refactoring to improve the quality of the code:
1501    
1502       (i)   The utf8_table... variables are now declared "const".
1503    
1504       (ii)  The code for \cx, which used the "case flipping" table to upper case
1505             lower case letters, now just substracts 32. This is ASCII-specific,
1506             but the whole concept of \cx is ASCII-specific, so it seems
1507             reasonable.
1508    
1509       (iii) PCRE was using its character types table to recognize decimal and
1510             hexadecimal digits in the pattern. This is silly, because it handles
1511             only 0-9, a-f, and A-F, but the character types table is locale-
1512             specific, which means strange things might happen. A private
1513             table is now used for this - though it costs 256 bytes, a table is
1514             much faster than multiple explicit tests. Of course, the standard
1515             character types table is still used for matching digits in subject
1516             strings against \d.
1517    
1518       (iv)  Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1519             ending in _t are). So I've renamed it as ESC_tee.
1520    
1521    3. The first argument for regexec() in the POSIX wrapper should have been
1522       defined as "const".
1523    
1524    4. Changed pcretest to use malloc() for its buffers so that they can be
1525       Electric Fenced for debugging.
1526    
1527    5. There were several places in the code where, in UTF-8 mode, PCRE would try
1528       to read one or more bytes before the start of the subject string. Often this
1529       had no effect on PCRE's behaviour, but in some circumstances it could
1530       provoke a segmentation fault.
1531    
1532    6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1533       to try to read one or more bytes before the start of the subject string.
1534    
1535    7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1536       UTF-8 support could misbehave in various ways if the subject string
1537       contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1538       area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1539       back over UTF-8 characters.)
1540    
1541    
1542    Version 4.2 14-Apr-03
1543    ---------------------
1544    
1545    1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1546    
1547    2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1548         [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1549         [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1550         [WIN_PREFIX]: new variable, "cyg" for Cygwin
1551         * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1552           and BUILD_EXEEXT
1553         Note: automatic setting of the BUILD variables is not yet working
1554         set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1555           compile-time but not at link-time
1556         [LINK]: use for linking executables only
1557         make different versions for Windows and non-Windows
1558         [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1559           libraries
1560         [LINK_FOR_BUILD]: new variable
1561         [OBJEXT]: use throughout
1562         [EXEEXT]: use throughout
1563         <winshared>: new target
1564         <wininstall>: new target
1565         <dftables.o>: use native compiler
1566         <dftables>: use native linker
1567         <install>: handle Windows platform correctly
1568         <clean>: ditto
1569         <check>: ditto
1570         copy DLL to top builddir before testing
1571    
1572       As part of these changes, -no-undefined was removed again. This was reported
1573       to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1574       in any case.
1575    
1576    3. Some tidies to get rid of compiler warnings:
1577    
1578       . In the match_data structure, match_limit was an unsigned long int, whereas
1579         match_call_count was an int. I've made them both unsigned long ints.
1580    
1581       . In pcretest the fact that a const uschar * doesn't automatically cast to
1582         a void * provoked a warning.
1583    
1584       . Turning on some more compiler warnings threw up some "shadow" variables
1585         and a few more missing casts.
1586    
1587    4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1588       option, a class that contained a single character with a value between 128
1589       and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1590    
1591    5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1592       option, a class that contained several characters, but with at least one
1593       whose value was between 128 and 255 caused PCRE to crash.
1594    
1595    
1596    Version 4.1 12-Mar-03
1597    ---------------------
1598    
1599    1. Compiling with gcc -pedantic found a couple of places where casts were
1600    needed, and a string in dftables.c that was longer than standard compilers are
1601    required to support.
1602    
1603    2. Compiling with Sun's compiler found a few more places where the code could
1604    be tidied up in order to avoid warnings.
1605    
1606    3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1607    first of these names is deprecated in the latest Autoconf in favour of the name
1608    CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1609    compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1610    analogy I have changed it to CFLAGS_FOR_BUILD.
1611    
1612    4. Added -no-undefined to the linking command in the Makefile, because this is
1613    apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1614    linking step for the pcreposix library.
1615    
1616    5. PCRE was failing to diagnose the case of two named groups with the same
1617    name.
1618    
1619    6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1620    literal character that is needed in the subject for a match, and scans along to
1621    ensure that it is present before embarking on the full matching process. This
1622    saves time in cases of nested unlimited repeats that are never going to match.
1623    Problem: the scan can take a lot of time if the subject is very long (e.g.
1624    megabytes), thus penalizing straightforward matches. It is now done only if the
1625    amount of subject to be scanned is less than 1000 bytes.
1626    
1627    7. A lesser problem with the same optimization is that it was recording the
1628    first character of an anchored pattern as "needed", thus provoking a search
1629    right along the subject, even when the first match of the pattern was going to
1630    fail. The "needed" character is now not set for anchored patterns, unless it
1631    follows something in the pattern that is of non-fixed length. Thus, it still
1632    fulfils its original purpose of finding quick non-matches in cases of nested
1633    unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1634    
1635    
1636    Version 4.0 17-Feb-03
1637    ---------------------
1638    
1639    1. If a comment in an extended regex that started immediately after a meta-item
1640    extended to the end of string, PCRE compiled incorrect data. This could lead to
1641    all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1642    
1643    2. Moved to autoconf 2.53 and libtool 1.4.2.
1644    
1645    3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1646    the special perltest8 script is no longer needed - all the tests can be run
1647    from a single perltest script.
1648    
1649    4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1650    by \s. It has now been removed in PCRE. This means it isn't recognized as
1651    whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1652    class [:space:] *does* include VT, thereby creating a mess.
1653    
1654    5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1655    space and tab.
1656    
1657    6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1658    its new features into the main test script, reducing the number of scripts.
1659    
1660    7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1661    were backward compatible, and made the (?i) apply to the whole pattern, as if
1662    /i were given. Now it behaves more logically, and applies the option setting
1663    only to what follows. PCRE has been changed to follow suit. However, if it
1664    finds options settings right at the start of the pattern, it extracts them into
1665    the global options, as before. Thus, they show up in the info data.
1666    
1667    8. Added support for the \Q...\E escape sequence. Characters in between are
1668    treated as literals. This is slightly different from Perl in that $ and @ are
1669    also handled as literals inside the quotes. In Perl, they will cause variable
1670    interpolation. Note the following examples:
1671    
1672        Pattern            PCRE matches      Perl matches
1673    
1674        \Qabc$xyz\E        abc$xyz           abc followed by the contents of $xyz
1675        \Qabc\$xyz\E       abc\$xyz          abc\$xyz
1676        \Qabc\E\$\Qxyz\E   abc$xyz           abc$xyz
1677    
1678    For compatibility with Perl, \Q...\E sequences are recognized inside character
1679    classes as well as outside them.
1680    
1681    9. Re-organized 3 code statements in pcretest to avoid "overflow in
1682    floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1683    (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1684    signed/unsigned warnings.
1685    
1686    10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1687    option for pcretest, so I've replaced it by a simple function that does just
1688    that job.
1689    
1690    11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1691    "pcregrep -".
1692    
1693    12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1694    Java package. This provides some syntactic sugar for simple cases of what my
1695    documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1696    as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1697    item, you can use this simplified notation. Note that only makes sense with
1698    greedy quantifiers. Consequently, the use of the possessive quantifier forces
1699    greediness, whatever the setting of the PCRE_UNGREEDY option.
1700    
1701    13. A change of greediness default within a pattern was not taking effect at
1702    the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1703    subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1704    was abstracted outside.
1705    
1706    14. PCRE now supports the \G assertion. It is true when the current matching
1707    position is at the start point of the match. This differs from \A when the
1708    starting offset is non-zero. Used with the /g option of pcretest (or similar
1709    code), it works in the same way as it does for Perl's /g option. If all
1710    alternatives of a regex begin with \G, the expression is anchored to the start
1711    match position, and the "anchored" flag is set in the compiled expression.
1712    
1713    15. Some bugs concerning the handling of certain option changes within patterns
1714    have been fixed. These applied to options other than (?ims). For example,
1715    "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1716    been the other way round. Some of this was related to change 7 above.
1717    
1718    16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1719    features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1720    and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1721    POSIX classes only within a class (e.g. /[[:alpha:]]/).
1722    
1723    17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1724    mode. Unlike ".", it always matches newline, whatever the setting of
1725    PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1726    assertions. Perl allows it, but it doesn't (in general) work because it can't
1727    calculate the length of the lookbehind. At least, that's the case for Perl
1728    5.8.0 - I've been told they are going to document that it doesn't work in
1729    future.
1730    
1731    18. Added an error diagnosis for escapes that PCRE does not support: these are
1732    \L, \l, \N, \P, \p, \U, \u, and \X.
1733    
1734    19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1735    reading past the end of the pattern in cases such as /[abcd/.
1736    
1737    20. PCRE was getting more memory than necessary for patterns with classes that
1738    contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1739    
1740    21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1741    compiling PCRE for use with Virtual Pascal.
1742    
1743    22. Small fix to the Makefile to make it work properly if the build is done
1744    outside the source tree.
1745    
1746    23. Added a new extension: a condition to go with recursion. If a conditional
1747    subpattern starts with (?(R) the "true" branch is used if recursion has
1748    happened, whereas the "false" branch is used only at the top level.
1749    
1750    24. When there was a very long string of literal characters (over 255 bytes
1751    without UTF support, over 250 bytes with UTF support), the computation of how
1752    much memory was required could be incorrect, leading to segfaults or other
1753    strange effects.
1754    
1755    25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1756    start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1757    there was a subsequent back reference to those brackets. This meant that, for
1758    example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1759    possible to check for precisely this case. All we can do is abandon the
1760    optimization if .* occurs inside capturing brackets when there are any back
1761    references whatsoever. (See below for a better fix that came later.)
1762    
1763    26. The handling of the optimization for finding the first character of a
1764    non-anchored pattern, and for finding a character that is required later in the
1765    match were failing in some cases. This didn't break the matching; it just
1766    failed to optimize when it could. The way this is done has been re-implemented.
1767    
1768    27. Fixed typo in error message for invalid (?R item (it said "(?p").
1769    
1770    28. Added a new feature that provides some of the functionality that Perl
1771    provides with (?{...}). The facility is termed a "callout". The way it is done
1772    in PCRE is for the caller to provide an optional function, by setting
1773    pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1774    global variable. By default it is unset, which disables all calling out. To get
1775    the function called, the regex must include (?C) at appropriate points. This
1776    is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1777    This provides a means of identifying different callout points. When PCRE
1778    reaches such a point in the regex, if pcre_callout has been set, the external
1779    function is called. It is provided with data in a structure called
1780    pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1781    matching continues; if it returns a non-zero value, the match at the current
1782    point fails. However, backtracking will occur if possible. [This was changed
1783    later and other features added - see item 49 below.]
1784    
1785    29. pcretest is upgraded to test the callout functionality. It provides a
1786    callout function that displays information. By default, it shows the start of
1787    the match and the current position in the text. There are some new data escapes
1788    to vary what happens:
1789    
1790        \C+         in addition, show current contents of captured substrings
1791        \C-         do not supply a callout function
1792        \C!n        return 1 when callout number n is reached
1793        \C!n!m      return 1 when callout number n is reached for the mth time
1794    
1795    30. If pcregrep was called with the -l option and just a single file name, it
1796    output "<stdin>" if a match was found, instead of the file name.
1797    
1798    31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1799    slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1800    pcre_exec(). This saves a malloc/free per call. The default value of
1801    POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1802    when configuring.
1803    
1804    32. The default maximum size of a compiled pattern is 64K. There have been a
1805    few cases of people hitting this limit. The code now uses macros to handle the
1806    storing of links as offsets within the compiled pattern. It defaults to 2-byte
1807    links, but this can be changed to 3 or 4 bytes by --with-link-size when
1808    configuring. Tests 2 and 5 work only with 2-byte links because they output
1809    debugging information about compiled patterns.
1810    
1811    33. Internal code re-arrangements:
1812    
1813    (a) Moved the debugging function for printing out a compiled regex into
1814        its own source file (printint.c) and used #include to pull it into
1815        pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1816        separate copies.
1817    
1818    (b) Defined the list of op-code names for debugging as a macro in
1819        internal.h so that it is next to the definition of the opcodes.
1820    
1821    (c) Defined a table of op-code lengths for simpler skipping along compiled
1822        code. This is again a macro in internal.h so that it is next to the
1823        definition of the opcodes.
1824    
1825    34. Added support for recursive calls to individual subpatterns, along the
1826    lines of Robin Houston's patch (but implemented somewhat differently).
1827    
1828    35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1829    allow it to read and process whole directories in Win32. This code was
1830    contributed by Lionel Fourquaux; it has not been tested by me.
1831    
1832    36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1833    used to name a group. Names consist of alphanumerics and underscores, and must
1834    be unique. Back references use the syntax (?P=name) and recursive calls use
1835    (?P>name) which is a PCRE extension to the Python extension. Groups still have
1836    numbers. The function pcre_fullinfo() can be used after compilation to extract
1837    a name/number map. There are three relevant calls:
1838    
1839      PCRE_INFO_NAMEENTRYSIZE        yields the size of each entry in the map
1840      PCRE_INFO_NAMECOUNT            yields the number of entries
1841      PCRE_INFO_NAMETABLE            yields a pointer to the map.
1842    
1843    The map is a vector of fixed-size entries. The size of each entry depends on
1844    the length of the longest name used. The first two bytes of each entry are the
1845    group number, most significant byte first. There follows the corresponding
1846    name, zero terminated. The names are in alphabetical order.
1847    
1848    37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1849    case instead of 255. Making it the same both with and without UTF-8 support
1850    means that the same test output works with both.
1851    
1852    38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1853    calling malloc() with a zero argument.
1854    
1855    39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1856    optimization. I've improved things by keeping a bitmap of backreferences with
1857    numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1858    fact referenced, the optimization can be applied. It is unlikely that a
1859    relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1860    the match to follow \n) will appear inside brackets with a number greater than
1861    31, but if it does, any back reference > 31 suppresses the optimization.
1862    
1863    40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1864    of disabling numbered capturing parentheses. Any opening parenthesis that is
1865    not followed by ? behaves as if it were followed by ?: but named parentheses
1866    can still be used for capturing (and they will acquire numbers in the usual
1867    way).
1868    
1869    41. Redesigned the return codes from the match() function into yes/no/error so
1870    that errors can be passed back from deep inside the nested calls. A malloc
1871    failure while inside a recursive subpattern call now causes the
1872    PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
1873    
1874    42. It is now possible to set a limit on the number of times the match()
1875    function is called in a call to pcre_exec(). This facility makes it possible to
1876    limit the amount of recursion and backtracking, though not in a directly
1877    obvious way, because the match() function is used in a number of different
1878    circumstances. The count starts from zero for each position in the subject
1879    string (for non-anchored patterns). The default limit is, for compatibility, a
1880    large number, namely 10 000 000. You can change this in two ways:
1881    
1882    (a) When configuring PCRE before making, you can use --with-match-limit=n
1883        to set a default value for the compiled library.
1884    
1885    (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
1886        a different value is set. See 45 below.
1887    
1888    If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
1889    
1890    43. Added a new function pcre_config(int, void *) to enable run-time extraction
1891    of things that can be changed at compile time. The first argument specifies
1892    what is wanted and the second points to where the information is to be placed.
1893    The current list of available information is:
1894    
1895      PCRE_CONFIG_UTF8
1896    
1897    The output is an integer that is set to one if UTF-8 support is available;
1898    otherwise it is set to zero.
1899    
1900      PCRE_CONFIG_NEWLINE
1901    
1902    The output is an integer that it set to the value of the code that is used for
1903    newline. It is either LF (10) or CR (13).
1904    
1905      PCRE_CONFIG_LINK_SIZE
1906    
1907    The output is an integer that contains the number of bytes used for internal
1908    linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
1909    
1910      PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
1911    
1912    The output is an integer that contains the threshold above which the POSIX
1913    interface uses malloc() for output vectors. See item 31 above.
1914    
1915      PCRE_CONFIG_MATCH_LIMIT
1916    
1917    The output is an unsigned integer that contains the default limit of the number
1918    of match() calls in a pcre_exec() execution. See 42 above.
1919    
1920    44. pcretest has been upgraded by the addition of the -C option. This causes it
1921    to extract all the available output from the new pcre_config() function, and to
1922    output it. The program then exits immediately.
1923    
1924    45. A need has arisen to pass over additional data with calls to pcre_exec() in
1925    order to support additional features. One way would have been to define
1926    pcre_exec2() (for example) with extra arguments, but this would not have been
1927    extensible, and would also have required all calls to the original function to
1928    be mapped to the new one. Instead, I have chosen to extend the mechanism that
1929    is used for passing in "extra" data from pcre_study().
1930    
1931    The pcre_extra structure is now exposed and defined in pcre.h. It currently
1932    contains the following fields:
1933    
1934      flags         a bitmap indicating which of the following fields are set
1935      study_data    opaque data from pcre_study()
1936      match_limit   a way of specifying a limit on match() calls for a specific
1937                      call to pcre_exec()
1938      callout_data  data for callouts (see 49 below)
1939    
1940    The flag bits are also defined in pcre.h, and are
1941    
1942      PCRE_EXTRA_STUDY_DATA
1943      PCRE_EXTRA_MATCH_LIMIT
1944      PCRE_EXTRA_CALLOUT_DATA
1945    
1946    The pcre_study() function now returns one of these new pcre_extra blocks, with
1947    the actual study data pointed to by the study_data field, and the
1948    PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
1949    before. That is, this change is entirely upwards-compatible and requires no
1950    change to existing code.
1951    
1952    If you want to pass in additional data to pcre_exec(), you can either place it
1953    in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
1954    block.
1955    
1956    46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
1957    data string contains the escape sequence \M, pcretest calls pcre_exec() several
1958    times with different match limits, until it finds the minimum value needed for
1959    pcre_exec() to complete. The value is then output. This can be instructive; for
1960    most simple matches the number is quite small, but for pathological cases it
1961    gets very large very quickly.
1962    
1963    47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
1964    returns the size of the data block pointed to by the study_data field in a
1965    pcre_extra block, that is, the value that was passed as the argument to
1966    pcre_malloc() when PCRE was getting memory in which to place the information
1967    created by pcre_study(). The fourth argument should point to a size_t variable.
1968    pcretest has been extended so that this information is shown after a successful
1969    pcre_study() call when information about the compiled regex is being displayed.
1970    
1971    48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
1972    because what follows is always an absolute path. (Later: it turns out that this
1973    is more than cosmetic for MinGW, because it doesn't like empty path
1974    components.)
1975    
1976    49. Some changes have been made to the callout feature (see 28 above):
1977    
1978    (i)  A callout function now has three choices for what it returns:
1979    
1980           0  =>  success, carry on matching
1981         > 0  =>  failure at this point, but backtrack if possible
1982         < 0  =>  serious error, return this value from pcre_exec()
1983    
1984         Negative values should normally be chosen from the set of PCRE_ERROR_xxx
1985         values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
1986         "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
1987         use by callout functions. It will never be used by PCRE itself.
1988    
1989    (ii) The pcre_extra structure (see 45 above) has a void * field called
1990         callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
1991         pcre_callout_block structure has a field of the same name. The contents of
1992         the field passed in the pcre_extra structure are passed to the callout
1993         function in the corresponding field in the callout block. This makes it
1994         easier to use the same callout-containing regex from multiple threads. For
1995         testing, the pcretest program has a new data escape
1996    
1997           \C*n        pass the number n (may be negative) as callout_data
1998    
1999         If the callout function in pcretest receives a non-zero value as
2000         callout_data, it returns that value.
2001    
2002    50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2003    there were some redundant $(CFLAGS) in commands that are now specified as
2004    $(LINK), which already includes $(CFLAGS).
2005    
2006    51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2007    has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2008    with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2009    one-byte characters throughout. Note that case-insensitive matching applies
2010    only to characters whose values are less than 256. PCRE doesn't support the
2011    notion of cases for higher-valued characters.
2012    
2013    (i)   A character class whose characters are all within 0-255 is handled as
2014          a bit map, and the map is inverted for negative classes. Previously, a
2015          character > 255 always failed to match such a class; however it should
2016          match if the class was a negative one (e.g. [^ab]). This has been fixed.
2017    
2018    (ii)  A negated character class with a single character < 255 is coded as
2019          "not this character" (OP_NOT). This wasn't working properly when the test
2020          character was multibyte, either singly or repeated.
2021    
2022    (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2023          mode, for example: \x{100}{2,3}.
2024    
2025    (iv)  The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2026          singly or repeated) now correctly test multibyte characters. However,
2027          PCRE doesn't recognize any characters with values greater than 255 as
2028          digits, spaces, or word characters. Such characters always match \D, \S,
2029          and \W, and never match \d, \s, or \w.
2030    
2031    (v)   Classes may now contain characters and character ranges with values
2032          greater than 255. For example: [ab\x{100}-\x{400}].
2033    
2034    (vi)  pcregrep now has a --utf-8 option (synonym -u) which makes it call
2035          PCRE in UTF-8 mode.
2036    
2037    52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2038    PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2039    retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2040    value.)
2041    
2042    53. The single man page has become too large. I have therefore split it up into
2043    a number of separate man pages. These also give rise to individual HTML pages;
2044    these are now put in a separate directory, and there is an index.html page that
2045    lists them all. Some hyperlinking between the pages has been installed.
2046    
2047    54. Added convenience functions for handling named capturing parentheses.
2048    
2049    55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2050    aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2051    true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2052    are faulted.
2053    
2054    56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2055    calling configure. These values are used when compiling the dftables.c program
2056    which is run to generate the source of the default character tables. They
2057    default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2058    you will need to set these values.
2059    
2060    57. Updated the building process for Windows DLL, as provided by Fred Cox.
2061    
2062    
2063    Version 3.9 02-Jan-02
2064    ---------------------
2065    
2066    1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2067    
2068    2. If --disable-static was given, the building process failed when trying to
2069    build pcretest and pcregrep. (For some reason it was using libtool to compile
2070    them, which is not right, as they aren't part of the library.)
2071    
2072    
2073    Version 3.8 18-Dec-01
2074    ---------------------
2075    
2076    1. The experimental UTF-8 code was completely screwed up. It was packing the
2077    bytes in the wrong order. How dumb can you get?
2078    
2079    
2080    Version 3.7 29-Oct-01
2081    ---------------------
2082    
2083    1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2084    This caused pcretest, when used on the test data, to segfault. Unfortunately,
2085    this didn't happen under Solaris 8, where I normally test things.
2086    
2087    2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2088    doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2089    isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2090    this fix an hour or so after the initial 3.7 release.)
2091    
2092    
2093    Version 3.6 23-Oct-01
2094    ---------------------
2095    
2096    1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2097    offsets passed as NULL with zero offset count.
2098    
2099    2. The config.guess and config.sub files had not been updated when I moved to
2100    the latest autoconf.
2101    
2102    
2103    Version 3.5 15-Aug-01
2104    ---------------------
2105    
2106    1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2107    had been forgotten.
2108    
2109    2. By using declared but undefined structures, we can avoid using "void"
2110    definitions in pcre.h while keeping the internal definitions of the structures
2111    private.
2112    
2113    3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2114    user point of view, this means that both static and shared libraries are built
2115    by default, but this can be individually controlled. More of the work of
2116    handling this static/shared cases is now inside libtool instead of PCRE's make
2117    file.
2118    
2119    4. The pcretest utility is now installed along with pcregrep because it is
2120    useful for users (to test regexs) and by doing this, it automatically gets
2121    relinked by libtool. The documentation has been turned into a man page, so
2122    there are now .1, .txt, and .html versions in /doc.
2123    
2124    5. Upgrades to pcregrep:
2125       (i)   Added long-form option names like gnu grep.
2126       (ii)  Added --help to list all options with an explanatory phrase.
2127       (iii) Added -r, --recursive to recurse into sub-directories.
2128       (iv)  Added -f, --file to read patterns from a file.
2129    
2130    6. pcre_exec() was referring to its "code" argument before testing that
2131    argument for NULL (and giving an error if it was NULL).
2132    
2133    7. Upgraded Makefile.in to allow for compiling in a different directory from
2134    the source directory.
2135    
2136    8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2137    options bits, the pointer it was passed was to an int instead of to an unsigned
2138    long int. This mattered only on 64-bit systems.
2139    
2140    9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2141    generated) instead of pcre.in, which it its source. Also made the same change
2142    in several of the .c files.
2143    
2144    10. A new release of gcc defines printf() as a macro, which broke pcretest
2145    because it had an ifdef in the middle of a string argument for printf(). Fixed
2146    by using separate calls to printf().
2147    
2148    11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2149    script, to force use of CR or LF instead of \n in the source. On non-Unix
2150    systems, the value can be set in config.h.
2151    
2152    12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2153    absolute limit. Changed the text of the error message to make this clear, and
2154    likewise updated the man page.
2155    
2156    13. The limit of 99 on the number of capturing subpatterns has been removed.
2157    The new limit is 65535, which I hope will not be a "real" limit.
2158    
2159    
2160    Version 3.4 22-Aug-00
2161    ---------------------
2162    
2163    1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2164    
2165    2. Diagnose condition (?(0) as an error instead of crashing on matching.
2166    
2167    
2168    Version 3.3 01-Aug-00
2169    ---------------------
2170    
2171    1. If an octal character was given, but the value was greater than \377, it
2172    was not getting masked to the least significant bits, as documented. This could
2173    lead to crashes in some systems.
2174    
2175    2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2176    the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2177    
2178    3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2179    These just pass their arguments on to (pcre_free)(), but they are provided
2180    because some uses of PCRE bind it to non-C systems that can call its functions,
2181    but cannot call free() or pcre_free() directly.
2182    
2183    4. Add "make test" as a synonym for "make check". Corrected some comments in
2184    the Makefile.
2185    
2186    5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2187    Makefile.
2188    
2189    6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2190    command called pgrep for grepping around the active processes.
2191    
2192    7. Added the beginnings of support for UTF-8 character strings.
2193    
2194    8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2195    RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2196    the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2197    out for the ar command.)
2198    
2199    
2200    Version 3.2 12-May-00
2201    ---------------------
2202    
2203    This is purely a bug fixing release.
2204    
2205    1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2206    of ZA. This was just one example of several cases that could provoke this bug,
2207    which was introduced by change 9 of version 2.00. The code for breaking
2208    infinite loops after an iteration that matches an empty string was't working
2209    correctly.
2210    
2211    2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2212    when matched against abbab (for example). After matching an empty string, it
2213    wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2214    caused it to match further down the string than it should.
2215    
2216    3. The code contained an inclusion of sys/types.h. It isn't clear why this
2217    was there because it doesn't seem to be needed, and it causes trouble on some
2218    systems, as it is not a Standard C header. It has been removed.
2219    
2220    4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2221    were reported on the Macintosh. The changes were from
2222    
2223      while ((c = *(++ptr)) != 0 && c != '\n');
2224    to
2225      while ((c = *(++ptr)) != 0 && c != '\n') ;
2226    
2227    Totally extraordinary, but if that's what it takes...
2228    
2229    5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2230    available. Added HAVE_BCOPY and an autoconf test for it; if neither
2231    HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2232    assumes the way PCRE uses memmove() (always moving upwards).
2233    
2234    6. PCRE is being used in one environment where strchr() is not available. There
2235    was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2236    faster code anyway.
2237    
2238    
2239    Version 3.1 09-Feb-00
2240    ---------------------
2241    
2242    The only change in this release is the fixing of some bugs in Makefile.in for
2243    the "install" target:
2244    
2245    (1) It was failing to install pcreposix.h.
2246    
2247    (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2248    
2249  Version 2.09 14-Sep-99  
2250  ----------------------  Version 3.0 01-Feb-00
2251    ---------------------
2252    
2253  1. Add support for the /+ modifier to perltest (to output $` like it does in  1. Add support for the /+ modifier to perltest (to output $` like it does in
2254  pcretest).  pcretest).
# Line 23  captured string vector to pcre_exec(), b Line 2268  captured string vector to pcre_exec(), b
2268  required a bigger vector, with some working space on the end. This means that  required a bigger vector, with some working space on the end. This means that
2269  the POSIX wrapper now has to get and free some memory, and copy the results.  the POSIX wrapper now has to get and free some memory, and copy the results.
2270    
2271    6. Added some simple autoconf support, placing the test data and the
2272    documentation in separate directories, re-organizing some of the
2273    information files, and making it build pcre-config (a GNU standard). Also added
2274    libtool support for building PCRE as a shared library, which is now the
2275    default.
2276    
2277    7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2278    09 are not valid octal constants. Single digits will be used for minor values
2279    less than 10.
2280    
2281    8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2282    existing programs that set these in the POSIX interface can use PCRE without
2283    modification.
2284    
2285    9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2286    return all that pcre_info() returns, plus additional data. The pcre_info()
2287    function is retained for compatibility, but is considered to be obsolete.
2288    
2289    10. Added experimental recursion feature (?R) to handle one common case that
2290    Perl 5.6 will be able to do with (?p{...}).
2291    
2292    11. Added support for POSIX character classes like [:alpha:], which Perl is
2293    adopting.
2294    
2295    
2296  Version 2.08 31-Aug-99  Version 2.08 31-Aug-99
2297  ----------------------  ----------------------

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