/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Diff of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 83 by nigel, Sat Feb 24 21:41:06 2007 UTC revision 231 by ph10, Tue Sep 11 11:15:33 2007 UTC
# Line 1  Line 1 
1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4    Version 7.4 10-Sep-07
5    ---------------------
6    
7    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
8        means that a class such as [\s] counted as "explicit reference to CR or
9        LF". That isn't really right - the whole point of the change was to try to
10        help when there was an actual mention of one of the two characters. So now
11        the change happens only if \r or \n (or a literal CR or LF) character is
12        encountered.
13    
14    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
15        of both had grown to the point where there were only 3 bits left.
16        Fortunately, there was spare space in the data structure, and so I have
17        moved the internal flags into a new 16-bit field to free up more option
18        bits.
19    
20    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
21        but did not set the internal JCHANGED flag - either of these is enough to
22        control the way the "get" function works - but the PCRE_INFO_JCHANGED
23        facility is supposed to tell if (?J) was ever used, so now (?J) at the
24        start sets both bits.
25    
26    4.  Added options (at build time, compile time, exec time) to change \R from
27        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
28    
29    
30    Version 7.3 28-Aug-07
31    ---------------------
32    
33     1. In the rejigging of the build system that eventually resulted in 7.1, the
34        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
35        brackets there is not right, since it causes compilers to look for an
36        installed pcre.h, not the version that is in the source that is being
37        compiled (which of course may be different). I have changed it back to:
38    
39          #include "pcre.h"
40    
41        I have a vague recollection that the change was concerned with compiling in
42        different directories, but in the new build system, that is taken care of
43        by the VPATH setting the Makefile.
44    
45     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
46        when the subject happened to end in the byte 0x85 (e.g. if the last
47        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
48        characters but of course it shouldn't be taken as a newline when it is part
49        of another character. The bug was that, for an unlimited repeat of . in
50        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
51        characters when looking for a newline.
52    
53     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
54    
55     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
56        in debug output.
57    
58     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
59        long printing in the pcrecpp unittest when running under MinGW.
60    
61     6. ESC_K was left out of the EBCDIC table.
62    
63     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
64        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
65        limit also applies to "virtual nesting" when a pattern is recursive, and in
66        this case 1000 isn't so big. I have been able to remove this limit at the
67        expense of backing off one optimization in certain circumstances. Normally,
68        when pcre_exec() would call its internal match() function recursively and
69        immediately return the result unconditionally, it uses a "tail recursion"
70        feature to save stack. However, when a subpattern that can match an empty
71        string has an unlimited repetition quantifier, it no longer makes this
72        optimization. That gives it a stack frame in which to save the data for
73        checking that an empty string has been matched. Previously this was taken
74        from the 1000-entry workspace that had been reserved. So now there is no
75        explicit limit, but more stack is used.
76    
77     8. Applied Daniel's patches to solve problems with the import/export magic
78        syntax that is required for Windows, and which was going wrong for the
79        pcreposix and pcrecpp parts of the library. These were overlooked when this
80        problem was solved for the main library.
81    
82     9. There were some crude static tests to avoid integer overflow when computing
83        the size of patterns that contain repeated groups with explicit upper
84        limits. As the maximum quantifier is 65535, the maximum group length was
85        set at 30,000 so that the product of these two numbers did not overflow a
86        32-bit integer. However, it turns out that people want to use groups that
87        are longer than 30,000 bytes (though not repeat them that many times).
88        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
89        made it possible to implement the integer overflow checks in a much more
90        dynamic way, which I have now done. The artificial limitation on group
91        length has been removed - we now have only the limit on the total length of
92        the compiled pattern, which depends on the LINK_SIZE setting.
93    
94    10. Fixed a bug in the documentation for get/copy named substring when
95        duplicate names are permitted. If none of the named substrings are set, the
96        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
97        empty string.
98    
99    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
100        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
101        because the ] is interpreted as the first data character and the
102        terminating ] is not found. PCRE has been made compatible with Perl in this
103        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
104        cause memory overwriting.
105    
106    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
107        string has been matched (to stop an infinite loop). It was not recognizing
108        a conditional subpattern that could match an empty string if that
109        subpattern was within another subpattern. For example, it looped when
110        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
111        condition was not nested. This bug has been fixed.
112    
113    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
114        past the start of the subject in the presence of bytes with the top bit
115        set, for example "\x8aBCD".
116    
117    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
118        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
119    
120    14. Optimized (?!) to (*FAIL).
121    
122    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
123        This restricts code points to be within the range 0 to 0x10FFFF, excluding
124        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
125        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
126        does: it's just the validity check that is more restrictive.
127    
128    16. Inserted checks for integer overflows during escape sequence (backslash)
129        processing, and also fixed erroneous offset values for syntax errors during
130        backslash processing.
131    
132    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
133        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
134    
135    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
136        caused an overrun.
137    
138    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
139        something other than just ASCII characters) inside a group that had an
140        unlimited repeat caused a loop at compile time (while checking to see
141        whether the group could match an empty string).
142    
143    20. Debugging a pattern containing \p or \P could cause a crash. For example,
144        [\P{Any}] did so. (Error in the code for printing property names.)
145    
146    21. An orphan \E inside a character class could cause a crash.
147    
148    22. A repeated capturing bracket such as (A)? could cause a wild memory
149        reference during compilation.
150    
151    23. There are several functions in pcre_compile() that scan along a compiled
152        expression for various reasons (e.g. to see if it's fixed length for look
153        behind). There were bugs in these functions when a repeated \p or \P was
154        present in the pattern. These operators have additional parameters compared
155        with \d, etc, and these were not being taken into account when moving along
156        the compiled data. Specifically:
157    
158        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
159            length.
160    
161        (b) An item such as \pL+ within a repeated group could cause crashes or
162            loops.
163    
164        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
165            "reference to non-existent subpattern" error.
166    
167        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
168    
169    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
170        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
171    
172    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
173    
174    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
175        character were causing crashes (broken optimization).
176    
177    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
178        \p or \P) caused a compile-time loop.
179    
180    28. More problems have arisen in unanchored patterns when CRLF is a valid line
181        break. For example, the unstudied pattern [\r\n]A does not match the string
182        "\r\nA" because change 7.0/46 below moves the current point on by two
183        characters after failing to match at the start. However, the pattern \nA
184        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
185        the same is true. There doesn't seem any very clean way out of this, but
186        what I have chosen to do makes the common cases work: PCRE now takes note
187        of whether there can be an explicit match for \r or \n anywhere in the
188        pattern, and if so, 7.0/46 no longer applies. As part of this change,
189        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
190        pattern has explicit CR or LF references.
191    
192    29. Added (*CR) etc for changing newline setting at start of pattern.
193    
194    
195    Version 7.2 19-Jun-07
196    ---------------------
197    
198     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
199        which is apparently normally available under Windows.
200    
201     2. Re-jig the pcregrep tests with different newline settings in an attempt
202        to make them independent of the local environment's newline setting.
203    
204     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
205    
206     4. Some of the "internals" tests were previously cut out when the link size
207        was not 2, because the output contained actual offsets. The recent new
208        "Z" feature of pcretest means that these can be cut out, making the tests
209        usable with all link sizes.
210    
211     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
212        stack recursion. This gives a massive performance boost under BSD, but just
213        a small improvement under Linux. However, it saves one field in the frame
214        in all cases.
215    
216     6. Added more features from the forthcoming Perl 5.10:
217    
218        (a) (?-n) (where n is a string of digits) is a relative subroutine or
219            recursion call. It refers to the nth most recently opened parentheses.
220    
221        (b) (?+n) is also a relative subroutine call; it refers to the nth next
222            to be opened parentheses.
223    
224        (c) Conditions that refer to capturing parentheses can be specified
225            relatively, for example, (?(-2)... or (?(+3)...
226    
227        (d) \K resets the start of the current match so that everything before
228            is not part of it.
229    
230        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
231    
232        (f) \g{name} is another synonym - part of Perl 5.10's unification of
233            reference syntax.
234    
235        (g) (?| introduces a group in which the numbering of parentheses in each
236            alternative starts with the same number.
237    
238        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
239    
240     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
241        PCRE_INFO_JCHANGED.
242    
243     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
244        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
245        for detecting groups that can match an empty string.
246    
247     9. A pattern with a very large number of alternatives (more than several
248        hundred) was running out of internal workspace during the pre-compile
249        phase, where pcre_compile() figures out how much memory will be needed. A
250        bit of new cunning has reduced the workspace needed for groups with
251        alternatives. The 1000-alternative test pattern now uses 12 bytes of
252        workspace instead of running out of the 4096 that are available.
253    
254    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
255    
256    11. Applied patch from Google to remove an optimization that didn't quite work.
257        The report of the bug said:
258    
259          pcrecpp::RE("a*").FullMatch("aaa") matches, while
260          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
261          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
262    
263    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
264        it matched the wrong number of bytes.
265    
266    
267    Version 7.1 24-Apr-07
268    ---------------------
269    
270     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
271        that is more "standard", making use of automake and other Autotools. There
272        is some re-arrangement of the files and adjustment of comments consequent
273        on this.
274    
275     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
276        for recursive directory scanning broke on some systems because the files
277        are not scanned in any specific order and on different systems the order
278        was different. A call to "sort" has been inserted into RunGrepTest for the
279        approprate test as a short-term fix. In the longer term there may be an
280        alternative.
281    
282     3. I had an email from Eric Raymond about problems translating some of PCRE's
283        man pages to HTML (despite the fact that I distribute HTML pages, some
284        people do their own conversions for various reasons). The problems
285        concerned the use of low-level troff macros .br and .in. I have therefore
286        removed all such uses from the man pages (some were redundant, some could
287        be replaced by .nf/.fi pairs). The 132html script that I use to generate
288        HTML has been updated to handle .nf/.fi and to complain if it encounters
289        .br or .in.
290    
291     4. Updated comments in configure.ac that get placed in config.h.in and also
292        arranged for config.h to be included in the distribution, with the name
293        config.h.generic, for the benefit of those who have to compile without
294        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
295    
296     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
297        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
298        makevp.bat for the current PCRE, using the additional files
299        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
300    
301     6. A Windows user reported a minor discrepancy with test 2, which turned out
302        to be caused by a trailing space on an input line that had got lost in his
303        copy. The trailing space was an accident, so I've just removed it.
304    
305     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
306        that is needed.
307    
308     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
309        as "const" (a) because they are and (b) because it helps the PHP
310        maintainers who have recently made a script to detect big data structures
311        in the php code that should be moved to the .rodata section. I remembered
312        to update Builducptable as well, so it won't revert if ucptable.h is ever
313        re-created.
314    
315     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
316        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
317        order to be able to cut out the UTF-8 tables in the latter when UTF-8
318        support is not required. This saves 1.5-2K of code, which is important in
319        some applications.
320    
321        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
322        so as not to refer to the tables, even though these functions will never be
323        called when UTF-8 support is disabled. Otherwise there are problems with a
324        shared library.
325    
326    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
327    
328        (a) It was defining its arguments as char * instead of void *.
329    
330        (b) It was assuming that all moves were upwards in memory; this was true
331            a long time ago when I wrote it, but is no longer the case.
332    
333        The emulated memove() is provided for those environments that have neither
334        memmove() nor bcopy(). I didn't think anyone used it these days, but that
335        is clearly not the case, as these two bugs were recently reported.
336    
337    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
338        and Detrail to create the HTML documentation, the .txt form of the man
339        pages, and it removes trailing spaces from listed files. It also creates
340        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
341        case, it wraps all the #defines with #ifndefs. This script should be run
342        before "make dist".
343    
344    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
345        with Unicode property support.
346    
347        (a) For a maximizing quantifier, if the two different cases of the
348            character were of different lengths in their UTF-8 codings (there are
349            some cases like this - I found 11), and the matching function had to
350            back up over a mixture of the two cases, it incorrectly assumed they
351            were both the same length.
352    
353        (b) When PCRE was configured to use the heap rather than the stack for
354            recursion during matching, it was not correctly preserving the data for
355            the other case of a UTF-8 character when checking ahead for a match
356            while processing a minimizing repeat. If the check also involved
357            matching a wide character, but failed, corruption could cause an
358            erroneous result when trying to check for a repeat of the original
359            character.
360    
361    13. Some tidying changes to the testing mechanism:
362    
363        (a) The RunTest script now detects the internal link size and whether there
364            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
365            values substituted by "configure". (The RunGrepTest script already did
366            this for UTF-8.) The configure.ac script no longer substitutes the
367            relevant variables.
368    
369        (b) The debugging options /B and /D in pcretest show the compiled bytecode
370            with length and offset values. This means that the output is different
371            for different internal link sizes. Test 2 is skipped for link sizes
372            other than 2 because of this, bypassing the problem. Unfortunately,
373            there was also a test in test 3 (the locale tests) that used /B and
374            failed for link sizes other than 2. Rather than cut the whole test out,
375            I have added a new /Z option to pcretest that replaces the length and
376            offset values with spaces. This is now used to make test 3 independent
377            of link size. (Test 2 will be tidied up later.)
378    
379    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
380        segmentation fault instead of returning the appropriate error message.
381    
382    15. In multiline mode when the newline sequence was set to "any", the pattern
383        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
384        This doesn't seem right; it now treats the CRLF combination as the line
385        ending, and so does not match in that case. It's only a pattern such as ^$
386        that would hit this one: something like ^ABC$ would have failed after \r
387        and then tried again after \r\n.
388    
389    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
390        in an attempt to make files that differ only in their line terminators
391        compare equal. This works on Linux.
392    
393    17. Under certain error circumstances pcregrep might try to free random memory
394        as it exited. This is now fixed, thanks to valgrind.
395    
396    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
397        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
398        was because its rules for how to advance for /g after matching an empty
399        string at the end of a line did not allow for this case. They now check for
400        it specially.
401    
402    20. pcretest is supposed to handle patterns and data of any length, by
403        extending its buffers when necessary. It was getting this wrong when the
404        buffer for a data line had to be extended.
405    
406    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
407        CRLF as a newline sequence.
408    
409    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
410        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
411        I have nevertheless tidied it up.
412    
413    23. Added some casts to kill warnings from HP-UX ia64 compiler.
414    
415    24. Added a man page for pcre-config.
416    
417    
418    Version 7.0 19-Dec-06
419    ---------------------
420    
421     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
422        moving to gcc 4.1.1.
423    
424     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
425        sys/time.h, which is documented as needed for this function. It doesn't
426        seem to matter on Linux, but it showed up on some releases of OS X.
427    
428     3. It seems that there are systems where bytes whose values are greater than
429        127 match isprint() in the "C" locale. The "C" locale should be the
430        default when a C program starts up. In most systems, only ASCII printing
431        characters match isprint(). This difference caused the output from pcretest
432        to vary, making some of the tests fail. I have changed pcretest so that:
433    
434        (a) When it is outputting text in the compiled version of a pattern, bytes
435            other than 32-126 are always shown as hex escapes.
436    
437        (b) When it is outputting text that is a matched part of a subject string,
438            it does the same, unless a different locale has been set for the match
439            (using the /L modifier). In this case, it uses isprint() to decide.
440    
441     4. Fixed a major bug that caused incorrect computation of the amount of memory
442        required for a compiled pattern when options that changed within the
443        pattern affected the logic of the preliminary scan that determines the
444        length. The relevant options are -x, and -i in UTF-8 mode. The result was
445        that the computed length was too small. The symptoms of this bug were
446        either the PCRE error "internal error: code overflow" from pcre_compile(),
447        or a glibc crash with a message such as "pcretest: free(): invalid next
448        size (fast)". Examples of patterns that provoked this bug (shown in
449        pcretest format) are:
450    
451          /(?-x: )/x
452          /(?x)(?-x: \s*#\s*)/
453          /((?i)[\x{c0}])/8
454          /(?i:[\x{c0}])/8
455    
456        HOWEVER: Change 17 below makes this fix obsolete as the memory computation
457        is now done differently.
458    
459     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
460        wrapper classes; (b) implement a new function in the C++ scanner that is
461        more efficient than the old way of doing things because it avoids levels of
462        recursion in the regex matching; (c) add a paragraph to the documentation
463        for the FullMatch() function.
464    
465     6. The escape sequence \n was being treated as whatever was defined as
466        "newline". Not only was this contrary to the documentation, which states
467        that \n is character 10 (hex 0A), but it also went horribly wrong when
468        "newline" was defined as CRLF. This has been fixed.
469    
470     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
471        was being set to -1 for the "end of line" case (supposedly a value that no
472        character can have). Though this value is never used (the check for end of
473        line is "zero bytes in current character"), it caused compiler complaints.
474        I've changed it to 0xffffffff.
475    
476     8. In pcre_version.c, the version string was being built by a sequence of
477        C macros that, in the event of PCRE_PRERELEASE being defined as an empty
478        string (as it is for production releases) called a macro with an empty
479        argument. The C standard says the result of this is undefined. The gcc
480        compiler treats it as an empty string (which was what was wanted) but it is
481        reported that Visual C gives an error. The source has been hacked around to
482        avoid this problem.
483    
484     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
485        builds of pcretest, and changed the call to _setmode() to use _O_BINARY
486        instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
487        of them did).
488    
489    10. Originally, pcretest opened its input and output without "b"; then I was
490        told that "b" was needed in some environments, so it was added for release
491        5.0 to both the input and output. (It makes no difference on Unix-like
492        systems.) Later I was told that it is wrong for the input on Windows. I've
493        now abstracted the modes into two macros, to make it easier to fiddle with
494        them, and removed "b" from the input mode under Windows.
495    
496    11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
497    
498    12. Added -help and --help to pcretest as an official way of being reminded
499        of the options.
500    
501    13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
502        and pcrecpp.cc because they annoy compilers at high warning levels.
503    
504    14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
505    
506    15. Fixed an occurrence of == in configure.ac that should have been = (shell
507        scripts are not C programs :-) and which was not noticed because it works
508        on Linux.
509    
510    16. pcretest is supposed to handle any length of pattern and data line (as one
511        line or as a continued sequence of lines) by extending its input buffer if
512        necessary. This feature was broken for very long pattern lines, leading to
513        a string of junk being passed to pcre_compile() if the pattern was longer
514        than about 50K.
515    
516    17. I have done a major re-factoring of the way pcre_compile() computes the
517        amount of memory needed for a compiled pattern. Previously, there was code
518        that made a preliminary scan of the pattern in order to do this. That was
519        OK when PCRE was new, but as the facilities have expanded, it has become
520        harder and harder to keep it in step with the real compile phase, and there
521        have been a number of bugs (see for example, 4 above). I have now found a
522        cunning way of running the real compile function in a "fake" mode that
523        enables it to compute how much memory it would need, while actually only
524        ever using a few hundred bytes of working memory and without too many
525        tests of the mode. This should make future maintenance and development
526        easier. A side effect of this work is that the limit of 200 on the nesting
527        depth of parentheses has been removed (though this was never a serious
528        limitation, I suspect). However, there is a downside: pcre_compile() now
529        runs more slowly than before (30% or more, depending on the pattern). I
530        hope this isn't a big issue. There is no effect on runtime performance.
531    
532    18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
533        newline (only possible for the last line of a file) and it was a
534        pattern that set a locale (followed by /Lsomething), pcretest crashed.
535    
536    19. Added additional timing features to pcretest. (1) The -tm option now times
537        matching only, not compiling. (2) Both -t and -tm can be followed, as a
538        separate command line item, by a number that specifies the number of
539        repeats to use when timing. The default is 50000; this gives better
540        precision, but takes uncomfortably long for very large patterns.
541    
542    20. Extended pcre_study() to be more clever in cases where a branch of a
543        subpattern has no definite first character. For example, (a*|b*)[cd] would
544        previously give no result from pcre_study(). Now it recognizes that the
545        first character must be a, b, c, or d.
546    
547    21. There was an incorrect error "recursive call could loop indefinitely" if
548        a subpattern (or the entire pattern) that was being tested for matching an
549        empty string contained only one non-empty item after a nested subpattern.
550        For example, the pattern (?>\x{100}*)\d(?R) provoked this error
551        incorrectly, because the \d was being skipped in the check.
552    
553    22. The pcretest program now has a new pattern option /B and a command line
554        option -b, which is equivalent to adding /B to every pattern. This causes
555        it to show the compiled bytecode, without the additional information that
556        -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
557        is the same as /B/I).
558    
559    23. A new optimization is now able automatically to treat some sequences such
560        as a*b as a*+b. More specifically, if something simple (such as a character
561        or a simple class like \d) has an unlimited quantifier, and is followed by
562        something that cannot possibly match the quantified thing, the quantifier
563        is automatically "possessified".
564    
565    24. A recursive reference to a subpattern whose number was greater than 39
566        went wrong under certain circumstances in UTF-8 mode. This bug could also
567        have affected the operation of pcre_study().
568    
569    25. Realized that a little bit of performance could be had by replacing
570        (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
571    
572    26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
573    
574    27. Possessive quantifiers such as a++ were previously implemented by turning
575        them into atomic groups such as ($>a+). Now they have their own opcodes,
576        which improves performance. This includes the automatically created ones
577        from 23 above.
578    
579    28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
580        lookahead was broken if it was not anchored. PCRE was mistakenly expecting
581        the first matched character to be a colon. This applied both to named and
582        numbered groups.
583    
584    29. The ucpinternal.h header file was missing its idempotency #ifdef.
585    
586    30. I was sent a "project" file called libpcre.a.dev which I understand makes
587        building PCRE on Windows easier, so I have included it in the distribution.
588    
589    31. There is now a check in pcretest against a ridiculously large number being
590        returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
591        loop, the loop is abandoned.
592    
593    32. Forward references to subpatterns in conditions such as (?(2)...) where
594        subpattern 2 is defined later cause pcre_compile() to search forwards in
595        the pattern for the relevant set of parentheses. This search went wrong
596        when there were unescaped parentheses in a character class, parentheses
597        escaped with \Q...\E, or parentheses in a #-comment in /x mode.
598    
599    33. "Subroutine" calls and backreferences were previously restricted to
600        referencing subpatterns earlier in the regex. This restriction has now
601        been removed.
602    
603    34. Added a number of extra features that are going to be in Perl 5.10. On the
604        whole, these are just syntactic alternatives for features that PCRE had
605        previously implemented using the Python syntax or my own invention. The
606        other formats are all retained for compatibility.
607    
608        (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
609            as (?P<name>...). The new forms, as well as being in Perl 5.10, are
610            also .NET compatible.
611    
612        (b) A recursion or subroutine call to a named group can now be defined as
613            (?&name) as well as (?P>name).
614    
615        (c) A backreference to a named group can now be defined as \k<name> or
616            \k'name' as well as (?P=name). The new forms, as well as being in Perl
617            5.10, are also .NET compatible.
618    
619        (d) A conditional reference to a named group can now use the syntax
620            (?(<name>) or (?('name') as well as (?(name).
621    
622        (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
623            groups (named and numbered) that are never evaluated inline, but can be
624            called as "subroutines" from elsewhere. In effect, the DEFINE condition
625            is always false. There may be only one alternative in such a group.
626    
627        (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
628            as the simple (?(R). The condition is true only if the most recent
629            recursion is that of the given number or name. It does not search out
630            through the entire recursion stack.
631    
632        (g) The escape \gN or \g{N} has been added, where N is a positive or
633            negative number, specifying an absolute or relative reference.
634    
635    35. Tidied to get rid of some further signed/unsigned compiler warnings and
636        some "unreachable code" warnings.
637    
638    36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
639        things, this adds five new scripts.
640    
641    37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
642        There were also incompatibilities regarding the handling of \Q..\E inside
643        character classes, for example with patterns like [\Qa\E-\Qz\E] where the
644        hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
645    
646    38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
647        matches an empty string, and forcibly breaks the loop. There were bugs in
648        this code in non-simple cases. For a pattern such as  ^(a()*)*  matched
649        against  aaaa  the result was just "a" rather than "aaaa", for example. Two
650        separate and independent bugs (that affected different cases) have been
651        fixed.
652    
653    39. Refactored the code to abolish the use of different opcodes for small
654        capturing bracket numbers. This is a tidy that I avoided doing when I
655        removed the limit on the number of capturing brackets for 3.5 back in 2001.
656        The new approach is not only tidier, it makes it possible to reduce the
657        memory needed to fix the previous bug (38).
658    
659    40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
660        sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
661        processing dot, circumflex, or dollar metacharacters, or #-comments in /x
662        mode.
663    
664    41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
665        report.
666    
667    42. Applied patch, originally from Ari Pollak, modified by Google, to allow
668        copy construction and assignment in the C++ wrapper.
669    
670    43. Updated pcregrep to support "--newline=any". In the process, I fixed a
671        couple of bugs that could have given wrong results in the "--newline=crlf"
672        case.
673    
674    44. Added a number of casts and did some reorganization of signed/unsigned int
675        variables following suggestions from Dair Grant. Also renamed the variable
676        "this" as "item" because it is a C++ keyword.
677    
678    45. Arranged for dftables to add
679    
680          #include "pcre_internal.h"
681    
682        to pcre_chartables.c because without it, gcc 4.x may remove the array
683        definition from the final binary if PCRE is built into a static library and
684        dead code stripping is activated.
685    
686    46. For an unanchored pattern, if a match attempt fails at the start of a
687        newline sequence, and the newline setting is CRLF or ANY, and the next two
688        characters are CRLF, advance by two characters instead of one.
689    
690    
691    Version 6.7 04-Jul-06
692    ---------------------
693    
694     1. In order to handle tests when input lines are enormously long, pcretest has
695        been re-factored so that it automatically extends its buffers when
696        necessary. The code is crude, but this _is_ just a test program. The
697        default size has been increased from 32K to 50K.
698    
699     2. The code in pcre_study() was using the value of the re argument before
700        testing it for NULL. (Of course, in any sensible call of the function, it
701        won't be NULL.)
702    
703     3. The memmove() emulation function in pcre_internal.h, which is used on
704        systems that lack both memmove() and bcopy() - that is, hardly ever -
705        was missing a "static" storage class specifier.
706    
707     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
708        containing an extended class (one that cannot be represented by a bitmap
709        because it contains high-valued characters or Unicode property items, e.g.
710        [\pZ]). Almost always one would set UTF-8 mode when processing such a
711        pattern, but PCRE should not loop if you do not (it no longer does).
712        [Detail: two cases were found: (a) a repeated subpattern containing an
713        extended class; (b) a recursive reference to a subpattern that followed a
714        previous extended class. It wasn't skipping over the extended class
715        correctly when UTF-8 mode was not set.]
716    
717     5. A negated single-character class was not being recognized as fixed-length
718        in lookbehind assertions such as (?<=[^f]), leading to an incorrect
719        compile error "lookbehind assertion is not fixed length".
720    
721     6. The RunPerlTest auxiliary script was showing an unexpected difference
722        between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
723        write a Perl script that can interpret lines of an input file either as
724        byte characters or as UTF-8, which is what "perltest" was being required to
725        do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
726        can't do is switch easily at run time between having the "use utf8;" pragma
727        or not. In the end, I fudged it by using the RunPerlTest script to insert
728        "use utf8;" explicitly for the UTF-8 tests.
729    
730     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
731        the end of the subject string, contrary to the documentation and to what
732        Perl does. This was true of both matching functions. Now it matches only at
733        the start of the subject and immediately after *internal* newlines.
734    
735     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
736        a pointer to an int instead of a pointer to an unsigned long int. This
737        caused problems on 64-bit systems.
738    
739     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
740        instance of the 'standard' template library not being so standard".
741    
742    10. There was no check on the number of named subpatterns nor the maximum
743        length of a subpattern name. The product of these values is used to compute
744        the size of the memory block for a compiled pattern. By supplying a very
745        long subpattern name and a large number of named subpatterns, the size
746        computation could be caused to overflow. This is now prevented by limiting
747        the length of names to 32 characters, and the number of named subpatterns
748        to 10,000.
749    
750    11. Subpatterns that are repeated with specific counts have to be replicated in
751        the compiled pattern. The size of memory for this was computed from the
752        length of the subpattern and the repeat count. The latter is limited to
753        65535, but there was no limit on the former, meaning that integer overflow
754        could in principle occur. The compiled length of a repeated subpattern is
755        now limited to 30,000 bytes in order to prevent this.
756    
757    12. Added the optional facility to have named substrings with the same name.
758    
759    13. Added the ability to use a named substring as a condition, using the
760        Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
761        are numbers (not recommended). Forward references are permitted.
762    
763    14. Added forward references in named backreferences (if you see what I mean).
764    
765    15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
766        pattern could run off the end of the subject. For example, the pattern
767        "(?s)(.{1,5})"8 did this with the subject "ab".
768    
769    16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
770        PCRE_CASELESS was set when matching characters that were quantified with ?
771        or *.
772    
773    17. A character class other than a single negated character that had a minimum
774        but no maximum quantifier - for example [ab]{6,} - was not handled
775        correctly by pce_dfa_exec(). It would match only one character.
776    
777    18. A valid (though odd) pattern that looked like a POSIX character
778        class but used an invalid character after [ (for example [[,abc,]]) caused
779        pcre_compile() to give the error "Failed: internal error: code overflow" or
780        in some cases to crash with a glibc free() error. This could even happen if
781        the pattern terminated after [[ but there just happened to be a sequence of
782        letters, a binary zero, and a closing ] in the memory that followed.
783    
784    19. Perl's treatment of octal escapes in the range \400 to \777 has changed
785        over the years. Originally (before any Unicode support), just the bottom 8
786        bits were taken. Thus, for example, \500 really meant \100. Nowadays the
787        output from "man perlunicode" includes this:
788    
789          The regular expression compiler produces polymorphic opcodes.  That
790          is, the pattern adapts to the data and automatically switches to
791          the Unicode character scheme when presented with Unicode data--or
792          instead uses a traditional byte scheme when presented with byte
793          data.
794    
795        Sadly, a wide octal escape does not cause a switch, and in a string with
796        no other multibyte characters, these octal escapes are treated as before.
797        Thus, in Perl, the pattern  /\500/ actually matches \100 but the pattern
798        /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
799        Unicode string.
800    
801        I have not perpetrated such confusion in PCRE. Up till now, it took just
802        the bottom 8 bits, as in old Perl. I have now made octal escapes with
803        values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
804        translate to the appropriate multibyte character.
805    
806    29. Applied some refactoring to reduce the number of warnings from Microsoft
807        and Borland compilers. This has included removing the fudge introduced
808        seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
809        a warning about an unused variable.
810    
811    21. PCRE has not included VT (character 0x0b) in the set of whitespace
812        characters since release 4.0, because Perl (from release 5.004) does not.
813        [Or at least, is documented not to: some releases seem to be in conflict
814        with the documentation.] However, when a pattern was studied with
815        pcre_study() and all its branches started with \s, PCRE still included VT
816        as a possible starting character. Of course, this did no harm; it just
817        caused an unnecessary match attempt.
818    
819    22. Removed a now-redundant internal flag bit that recorded the fact that case
820        dependency changed within the pattern. This was once needed for "required
821        byte" processing, but is no longer used. This recovers a now-scarce options
822        bit. Also moved the least significant internal flag bit to the most-
823        significant bit of the word, which was not previously used (hangover from
824        the days when it was an int rather than a uint) to free up another bit for
825        the future.
826    
827    23. Added support for CRLF line endings as well as CR and LF. As well as the
828        default being selectable at build time, it can now be changed at runtime
829        via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
830        specify that it is scanning data with non-default line endings.
831    
832    24. Changed the definition of CXXLINK to make it agree with the definition of
833        LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
834    
835    25. Applied Ian Taylor's patches to avoid using another stack frame for tail
836        recursions. This makes a big different to stack usage for some patterns.
837    
838    26. If a subpattern containing a named recursion or subroutine reference such
839        as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
840        the space required for the compiled pattern went wrong and gave too small a
841        value. Depending on the environment, this could lead to "Failed: internal
842        error: code overflow at offset 49" or "glibc detected double free or
843        corruption" errors.
844    
845    27. Applied patches from Google (a) to support the new newline modes and (b) to
846        advance over multibyte UTF-8 characters in GlobalReplace.
847    
848    28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
849        difference for some implementation of PCRE in some Windows version.
850    
851    29. Added some extra testing facilities to pcretest:
852    
853        \q<number>   in a data line sets the "match limit" value
854        \Q<number>   in a data line sets the "match recursion limt" value
855        -S <number>  sets the stack size, where <number> is in megabytes
856    
857        The -S option isn't available for Windows.
858    
859    
860    Version 6.6 06-Feb-06
861    ---------------------
862    
863     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
864        in pcreposix.h. I have copied the definition from pcre.h.
865    
866     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
867        because pcre.h is no longer a built file.
868    
869     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
870        not normally included in the compiled code.
871    
872    
873    Version 6.5 01-Feb-06
874    ---------------------
875    
876     1. When using the partial match feature with pcre_dfa_exec(), it was not
877        anchoring the second and subsequent partial matches at the new starting
878        point. This could lead to incorrect results. For example, with the pattern
879        /1234/, partially matching against "123" and then "a4" gave a match.
880    
881     2. Changes to pcregrep:
882    
883        (a) All non-match returns from pcre_exec() were being treated as failures
884            to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
885            error message is output. Some extra information is given for the
886            PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
887            probably the only errors that are likely to be caused by users (by
888            specifying a regex that has nested indefinite repeats, for instance).
889            If there are more than 20 of these errors, pcregrep is abandoned.
890    
891        (b) A binary zero was treated as data while matching, but terminated the
892            output line if it was written out. This has been fixed: binary zeroes
893            are now no different to any other data bytes.
894    
895        (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
896            used to set a locale for matching. The --locale=xxxx long option has
897            been added (no short equivalent) to specify a locale explicitly on the
898            pcregrep command, overriding the environment variables.
899    
900        (d) When -B was used with -n, some line numbers in the output were one less
901            than they should have been.
902    
903        (e) Added the -o (--only-matching) option.
904    
905        (f) If -A or -C was used with -c (count only), some lines of context were
906            accidentally printed for the final match.
907    
908        (g) Added the -H (--with-filename) option.
909    
910        (h) The combination of options -rh failed to suppress file names for files
911            that were found from directory arguments.
912    
913        (i) Added the -D (--devices) and -d (--directories) options.
914    
915        (j) Added the -F (--fixed-strings) option.
916    
917        (k) Allow "-" to be used as a file name for -f as well as for a data file.
918    
919        (l) Added the --colo(u)r option.
920    
921        (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
922            is not present by default.
923    
924     3. A nasty bug was discovered in the handling of recursive patterns, that is,
925        items such as (?R) or (?1), when the recursion could match a number of
926        alternatives. If it matched one of the alternatives, but subsequently,
927        outside the recursion, there was a failure, the code tried to back up into
928        the recursion. However, because of the way PCRE is implemented, this is not
929        possible, and the result was an incorrect result from the match.
930    
931        In order to prevent this happening, the specification of recursion has
932        been changed so that all such subpatterns are automatically treated as
933        atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
934    
935     4. I had overlooked the fact that, in some locales, there are characters for
936        which isalpha() is true but neither isupper() nor islower() are true. In
937        the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
938        and ordfeminine) are like this. This affected the treatment of \w and \W
939        when they appeared in character classes, but not when they appeared outside
940        a character class. The bit map for "word" characters is now created
941        separately from the results of isalnum() instead of just taking it from the
942        upper, lower, and digit maps. (Plus the underscore character, of course.)
943    
944     5. The above bug also affected the handling of POSIX character classes such as
945        [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
946        permanent tables. Instead, the bit maps for such a class were previously
947        created as the appropriate unions of the upper, lower, and digit bitmaps.
948        Now they are created by subtraction from the [[:word:]] class, which has
949        its own bitmap.
950    
951     6. The [[:blank:]] character class matches horizontal, but not vertical space.
952        It is created by subtracting the vertical space characters (\x09, \x0a,
953        \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
954        subtraction was done in the overall bitmap for a character class, meaning
955        that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
956        be recognized. This bug has been fixed.
957    
958     7. Patches from the folks at Google:
959    
960          (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
961          real life, but is still worth protecting against".
962    
963          (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
964          regular expressions".
965    
966          (c) pcre_scanner.cc: avoid use of std::count() because not all systems
967          have it.
968    
969          (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
970          "configure" and the latter not, in order to fix a problem somebody had
971          with compiling the Arg class on HP-UX.
972    
973          (e) Improve the error-handling of the C++ wrapper a little bit.
974    
975          (f) New tests for checking recursion limiting.
976    
977     8. The pcre_memmove() function, which is used only if the environment does not
978        have a standard memmove() function (and is therefore rarely compiled),
979        contained two bugs: (a) use of int instead of size_t, and (b) it was not
980        returning a result (though PCRE never actually uses the result).
981    
982     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
983        large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
984        returned instead of calling malloc() with an overflowing number that would
985        most likely cause subsequent chaos.
986    
987    10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
988    
989    11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
990        with this option is matched, the nmatch and pmatch options of regexec() are
991        ignored.
992    
993    12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
994        provided in case anyone wants to the the POSIX interface with UTF-8
995        strings.
996    
997    13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
998        C++ linking (needed for some HP-UX environments).
999    
1000    14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1001        (unused parameter) and in the pcre_printint() function (omitted "default"
1002        switch label when the default is to do nothing).
1003    
1004    15. Added some code to make it possible, when PCRE is compiled as a C++
1005        library, to replace subject pointers for pcre_exec() with a smart pointer
1006        class, thus making it possible to process discontinuous strings.
1007    
1008    16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1009        much the same function. They were added by different people who were trying
1010        to make PCRE easy to compile on non-Unix systems. It has been suggested
1011        that PCRE_EXPORT be abolished now that there is more automatic apparatus
1012        for compiling on Windows systems. I have therefore replaced it with
1013        PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1014        defaults to "extern" for C or "extern C" for C++, which works fine on
1015        Unix-like systems. It is now possible to override the value of PCRE_DATA_
1016        SCOPE with something explicit in config.h. In addition:
1017    
1018        (a) pcreposix.h still had just "extern" instead of either of these macros;
1019            I have replaced it with PCRE_DATA_SCOPE.
1020    
1021        (b) Functions such as _pcre_xclass(), which are internal to the library,
1022            but external in the C sense, all had PCRE_EXPORT in their definitions.
1023            This is apparently wrong for the Windows case, so I have removed it.
1024            (It makes no difference on Unix-like systems.)
1025    
1026    17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1027        of recursive calls to match(). This is different to MATCH_LIMIT because
1028        that limits the total number of calls to match(), not all of which increase
1029        the depth of recursion. Limiting the recursion depth limits the amount of
1030        stack (or heap if NO_RECURSE is set) that is used. The default can be set
1031        when PCRE is compiled, and changed at run time. A patch from Google adds
1032        this functionality to the C++ interface.
1033    
1034    18. Changes to the handling of Unicode character properties:
1035    
1036        (a) Updated the table to Unicode 4.1.0.
1037    
1038        (b) Recognize characters that are not in the table as "Cn" (undefined).
1039    
1040        (c) I revised the way the table is implemented to a much improved format
1041            which includes recognition of ranges. It now supports the ranges that
1042            are defined in UnicodeData.txt, and it also amalgamates other
1043            characters into ranges. This has reduced the number of entries in the
1044            table from around 16,000 to around 3,000, thus reducing its size
1045            considerably. I realized I did not need to use a tree structure after
1046            all - a binary chop search is just as efficient. Having reduced the
1047            number of entries, I extended their size from 6 bytes to 8 bytes to
1048            allow for more data.
1049    
1050        (d) Added support for Unicode script names via properties such as \p{Han}.
1051    
1052    19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1053        matching that character.
1054    
1055    20. When matching a repeated Unicode property with a minimum greater than zero,
1056        (for example \pL{2,}), PCRE could look past the end of the subject if it
1057        reached it while seeking the minimum number of characters. This could
1058        happen only if some of the characters were more than one byte long, because
1059        there is a check for at least the minimum number of bytes.
1060    
1061    21. Refactored the implementation of \p and \P so as to be more general, to
1062        allow for more different types of property in future. This has changed the
1063        compiled form incompatibly. Anybody with saved compiled patterns that use
1064        \p or \P will have to recompile them.
1065    
1066    22. Added "Any" and "L&" to the supported property types.
1067    
1068    23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1069        but give a compile time error if the value is greater than 0xff.
1070    
1071    24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1072        accidentally not being installed or uninstalled.
1073    
1074    25. The pcre.h file was built from pcre.h.in, but the only changes that were
1075        made were to insert the current release number. This seemed silly, because
1076        it made things harder for people building PCRE on systems that don't run
1077        "configure". I have turned pcre.h into a distributed file, no longer built
1078        by "configure", with the version identification directly included. There is
1079        no longer a pcre.h.in file.
1080    
1081        However, this change necessitated a change to the pcre-config script as
1082        well. It is built from pcre-config.in, and one of the substitutions was the
1083        release number. I have updated configure.ac so that ./configure now finds
1084        the release number by grepping pcre.h.
1085    
1086    26. Added the ability to run the tests under valgrind.
1087    
1088    
1089    Version 6.4 05-Sep-05
1090    ---------------------
1091    
1092     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1093        "--" to be printed when multiple files were scanned, even when none of the
1094        -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1095        consider it to be a bug, and have restored the previous behaviour.
1096    
1097     2. A couple of code tidies to get rid of compiler warnings.
1098    
1099     3. The pcretest program used to cheat by referring to symbols in the library
1100        whose names begin with _pcre_. These are internal symbols that are not
1101        really supposed to be visible externally, and in some environments it is
1102        possible to suppress them. The cheating is now confined to including
1103        certain files from the library's source, which is a bit cleaner.
1104    
1105     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1106        file's purpose clearer.
1107    
1108     5. Reorganized pcre_ucp_findchar().
1109    
1110    
1111  Version 6.3 15-Aug-05  Version 6.3 15-Aug-05
1112  ---------------------  ---------------------
1113    

Legend:
Removed from v.83  
changed lines
  Added in v.231

  ViewVC Help
Powered by ViewVC 1.1.5