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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4    Version 7.5 12-Nov-07
5    ---------------------
7    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
8        values in parens when parsing an RE using the C++ wrapper."
10    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
11        Characters greater than 255 were excluded from the class instead of being
12        included.
14    3.  The same bug as (2) above applied to negated POSIX classes such as
15        [:^space:].
17    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
18        defined or documented. It seems to have been a typo for PCRE_STATIC, so
19        I have changed it.
21    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
22        first named subpattern) and a construct such as (?&a) would reference the
23        first named subpattern whose name started with "a" (in other words, the
24        length check was missing). Both these problems are fixed. "Subpattern name
25        expected" is now given for (?&) (a zero-length name), and this patch also
26        makes it give the same error for \k'' (previously it complained that that
27        was a reference to a non-existent subpattern).
29    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
30        this is right because (?- can be followed by option settings as well as by
31        digits. I have, however, made the messages clearer.
33    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
34        than the number used in the conditional) now cause a compile-time error.
35        This is actually not compatible with Perl, which accepts such patterns, but
36        treats the conditional as always being FALSE (as PCRE used to), but it
37        seems to me that giving a diagnostic is better.
39    8.  Change "alphameric" to the more common word "alphanumeric" in comments
40        and messages.
42    9.  Fix two occurrences of "backslash" in comments that should have been
43        "backspace".
45    10. Remove two redundant lines of code that can never be obeyed (their function
46        was moved elsewhere).
48    11. The program that makes PCRE's Unicode character property table had a bug
49        which caused it to generate incorrect table entries for sequences of
50        characters that have the same character type, but are in different scripts.
51        It amalgamated them into a single range, with the script of the first of
52        them. In other words, some characters were in the wrong script. There were
53        thirteen such cases, affecting characters in the following ranges:
55          U+002b0 - U+002c1
56          U+0060c - U+0060d
57          U+0061e - U+00612
58          U+0064b - U+0065e
59          U+0074d - U+0076d
60          U+01800 - U+01805
61          U+01d00 - U+01d77
62          U+01d9b - U+01dbf
63          U+0200b - U+0200f
64          U+030fc - U+030fe
65          U+03260 - U+0327f
66          U+0fb46 - U+0fbb1
67          U+10450 - U+1049d
70    Version 7.4 21-Sep-07
71    ---------------------
73    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
74        means that a class such as [\s] counted as "explicit reference to CR or
75        LF". That isn't really right - the whole point of the change was to try to
76        help when there was an actual mention of one of the two characters. So now
77        the change happens only if \r or \n (or a literal CR or LF) character is
78        encountered.
80    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
81        of both had grown to the point where there were only 3 bits left.
82        Fortunately, there was spare space in the data structure, and so I have
83        moved the internal flags into a new 16-bit field to free up more option
84        bits.
86    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
87        but did not set the internal JCHANGED flag - either of these is enough to
88        control the way the "get" function works - but the PCRE_INFO_JCHANGED
89        facility is supposed to tell if (?J) was ever used, so now (?J) at the
90        start sets both bits.
92    4.  Added options (at build time, compile time, exec time) to change \R from
93        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
95    5.  doc/pcresyntax.html was missing from the distribution.
97    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
98        compatibility, even though it is no longer used.
100    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
101        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
102        windows.h file is present (where different names are used). [This was
103        reversed later after testing - see 16 below.]
105    8.  Changed all #include <config.h> to #include "config.h". There were also
106        some further <pcre.h> cases that I changed to "pcre.h".
108    9.  When pcregrep was used with the --colour option, it missed the line ending
109        sequence off the lines that it output.
111    10. It was pointed out to me that arrays of string pointers cause lots of
112        relocations when a shared library is dynamically loaded. A technique of
113        using a single long string with a table of offsets can drastically reduce
114        these. I have refactored PCRE in four places to do this. The result is
115        dramatic:
117          Originally:                          290
118          After changing UCP table:            187
119          After changing error message table:   43
120          After changing table of "verbs"       36
121          After changing table of Posix names   22
123        Thanks to the folks working on Gregex for glib for this insight.
125    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
126        unicode-properties was also set.
128    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
130    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
131        checked only for CRLF.
133    14. Added casts to pcretest.c to avoid compiler warnings.
135    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
137    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
138        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
139        entirely. This removes changes made in 7 above.
141    17. The CMake files have been updated, and there is now more information about
142        building with CMake in the NON-UNIX-USE document.
145    Version 7.3 28-Aug-07
146    ---------------------
148     1. In the rejigging of the build system that eventually resulted in 7.1, the
149        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
150        brackets there is not right, since it causes compilers to look for an
151        installed pcre.h, not the version that is in the source that is being
152        compiled (which of course may be different). I have changed it back to:
154          #include "pcre.h"
156        I have a vague recollection that the change was concerned with compiling in
157        different directories, but in the new build system, that is taken care of
158        by the VPATH setting the Makefile.
160     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
161        when the subject happened to end in the byte 0x85 (e.g. if the last
162        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
163        characters but of course it shouldn't be taken as a newline when it is part
164        of another character. The bug was that, for an unlimited repeat of . in
165        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
166        characters when looking for a newline.
168     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
170     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
171        in debug output.
173     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
174        long printing in the pcrecpp unittest when running under MinGW.
176     6. ESC_K was left out of the EBCDIC table.
178     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
179        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
180        limit also applies to "virtual nesting" when a pattern is recursive, and in
181        this case 1000 isn't so big. I have been able to remove this limit at the
182        expense of backing off one optimization in certain circumstances. Normally,
183        when pcre_exec() would call its internal match() function recursively and
184        immediately return the result unconditionally, it uses a "tail recursion"
185        feature to save stack. However, when a subpattern that can match an empty
186        string has an unlimited repetition quantifier, it no longer makes this
187        optimization. That gives it a stack frame in which to save the data for
188        checking that an empty string has been matched. Previously this was taken
189        from the 1000-entry workspace that had been reserved. So now there is no
190        explicit limit, but more stack is used.
192     8. Applied Daniel's patches to solve problems with the import/export magic
193        syntax that is required for Windows, and which was going wrong for the
194        pcreposix and pcrecpp parts of the library. These were overlooked when this
195        problem was solved for the main library.
197     9. There were some crude static tests to avoid integer overflow when computing
198        the size of patterns that contain repeated groups with explicit upper
199        limits. As the maximum quantifier is 65535, the maximum group length was
200        set at 30,000 so that the product of these two numbers did not overflow a
201        32-bit integer. However, it turns out that people want to use groups that
202        are longer than 30,000 bytes (though not repeat them that many times).
203        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
204        made it possible to implement the integer overflow checks in a much more
205        dynamic way, which I have now done. The artificial limitation on group
206        length has been removed - we now have only the limit on the total length of
207        the compiled pattern, which depends on the LINK_SIZE setting.
209    10. Fixed a bug in the documentation for get/copy named substring when
210        duplicate names are permitted. If none of the named substrings are set, the
211        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
212        empty string.
214    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
215        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
216        because the ] is interpreted as the first data character and the
217        terminating ] is not found. PCRE has been made compatible with Perl in this
218        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
219        cause memory overwriting.
221    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
222        string has been matched (to stop an infinite loop). It was not recognizing
223        a conditional subpattern that could match an empty string if that
224        subpattern was within another subpattern. For example, it looped when
225        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
226        condition was not nested. This bug has been fixed.
228    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
229        past the start of the subject in the presence of bytes with the top bit
230        set, for example "\x8aBCD".
232    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
233        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
235    14. Optimized (?!) to (*FAIL).
237    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
238        This restricts code points to be within the range 0 to 0x10FFFF, excluding
239        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
240        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
241        does: it's just the validity check that is more restrictive.
243    16. Inserted checks for integer overflows during escape sequence (backslash)
244        processing, and also fixed erroneous offset values for syntax errors during
245        backslash processing.
247    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
248        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
250    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
251        caused an overrun.
253    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
254        something other than just ASCII characters) inside a group that had an
255        unlimited repeat caused a loop at compile time (while checking to see
256        whether the group could match an empty string).
258    20. Debugging a pattern containing \p or \P could cause a crash. For example,
259        [\P{Any}] did so. (Error in the code for printing property names.)
261    21. An orphan \E inside a character class could cause a crash.
263    22. A repeated capturing bracket such as (A)? could cause a wild memory
264        reference during compilation.
266    23. There are several functions in pcre_compile() that scan along a compiled
267        expression for various reasons (e.g. to see if it's fixed length for look
268        behind). There were bugs in these functions when a repeated \p or \P was
269        present in the pattern. These operators have additional parameters compared
270        with \d, etc, and these were not being taken into account when moving along
271        the compiled data. Specifically:
273        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
274            length.
276        (b) An item such as \pL+ within a repeated group could cause crashes or
277            loops.
279        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
280            "reference to non-existent subpattern" error.
282        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
284    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
285        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
287    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
289    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
290        character were causing crashes (broken optimization).
292    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
293        \p or \P) caused a compile-time loop.
295    28. More problems have arisen in unanchored patterns when CRLF is a valid line
296        break. For example, the unstudied pattern [\r\n]A does not match the string
297        "\r\nA" because change 7.0/46 below moves the current point on by two
298        characters after failing to match at the start. However, the pattern \nA
299        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
300        the same is true. There doesn't seem any very clean way out of this, but
301        what I have chosen to do makes the common cases work: PCRE now takes note
302        of whether there can be an explicit match for \r or \n anywhere in the
303        pattern, and if so, 7.0/46 no longer applies. As part of this change,
304        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
305        pattern has explicit CR or LF references.
307    29. Added (*CR) etc for changing newline setting at start of pattern.
310    Version 7.2 19-Jun-07
311    ---------------------
313     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
314        which is apparently normally available under Windows.
316     2. Re-jig the pcregrep tests with different newline settings in an attempt
317        to make them independent of the local environment's newline setting.
319     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
321     4. Some of the "internals" tests were previously cut out when the link size
322        was not 2, because the output contained actual offsets. The recent new
323        "Z" feature of pcretest means that these can be cut out, making the tests
324        usable with all link sizes.
326     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
327        stack recursion. This gives a massive performance boost under BSD, but just
328        a small improvement under Linux. However, it saves one field in the frame
329        in all cases.
331     6. Added more features from the forthcoming Perl 5.10:
333        (a) (?-n) (where n is a string of digits) is a relative subroutine or
334            recursion call. It refers to the nth most recently opened parentheses.
336        (b) (?+n) is also a relative subroutine call; it refers to the nth next
337            to be opened parentheses.
339        (c) Conditions that refer to capturing parentheses can be specified
340            relatively, for example, (?(-2)... or (?(+3)...
342        (d) \K resets the start of the current match so that everything before
343            is not part of it.
345        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
347        (f) \g{name} is another synonym - part of Perl 5.10's unification of
348            reference syntax.
350        (g) (?| introduces a group in which the numbering of parentheses in each
351            alternative starts with the same number.
353        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
355     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
358     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
359        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
360        for detecting groups that can match an empty string.
362     9. A pattern with a very large number of alternatives (more than several
363        hundred) was running out of internal workspace during the pre-compile
364        phase, where pcre_compile() figures out how much memory will be needed. A
365        bit of new cunning has reduced the workspace needed for groups with
366        alternatives. The 1000-alternative test pattern now uses 12 bytes of
367        workspace instead of running out of the 4096 that are available.
369    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
371    11. Applied patch from Google to remove an optimization that didn't quite work.
372        The report of the bug said:
374          pcrecpp::RE("a*").FullMatch("aaa") matches, while
375          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
376          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
378    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
379        it matched the wrong number of bytes.
382    Version 7.1 24-Apr-07
383    ---------------------
385     1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
386        that is more "standard", making use of automake and other Autotools. There
387        is some re-arrangement of the files and adjustment of comments consequent
388        on this.
390     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
391        for recursive directory scanning broke on some systems because the files
392        are not scanned in any specific order and on different systems the order
393        was different. A call to "sort" has been inserted into RunGrepTest for the
394        approprate test as a short-term fix. In the longer term there may be an
395        alternative.
397     3. I had an email from Eric Raymond about problems translating some of PCRE's
398        man pages to HTML (despite the fact that I distribute HTML pages, some
399        people do their own conversions for various reasons). The problems
400        concerned the use of low-level troff macros .br and .in. I have therefore
401        removed all such uses from the man pages (some were redundant, some could
402        be replaced by .nf/.fi pairs). The 132html script that I use to generate
403        HTML has been updated to handle .nf/.fi and to complain if it encounters
404        .br or .in.
406     4. Updated comments in configure.ac that get placed in config.h.in and also
407        arranged for config.h to be included in the distribution, with the name
408        config.h.generic, for the benefit of those who have to compile without
409        Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
411     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
412        Weber: (1) pcre_internal.h was missing some function renames; (2) updated
413        makevp.bat for the current PCRE, using the additional files
414        makevp_c.txt, makevp_l.txt, and pcregexp.pas.
416     6. A Windows user reported a minor discrepancy with test 2, which turned out
417        to be caused by a trailing space on an input line that had got lost in his
418        copy. The trailing space was an accident, so I've just removed it.
420     7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
421        that is needed.
423     8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
424        as "const" (a) because they are and (b) because it helps the PHP
425        maintainers who have recently made a script to detect big data structures
426        in the php code that should be moved to the .rodata section. I remembered
427        to update Builducptable as well, so it won't revert if ucptable.h is ever
428        re-created.
430     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
431        pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
432        order to be able to cut out the UTF-8 tables in the latter when UTF-8
433        support is not required. This saves 1.5-2K of code, which is important in
434        some applications.
436        Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
437        so as not to refer to the tables, even though these functions will never be
438        called when UTF-8 support is disabled. Otherwise there are problems with a
439        shared library.
441    10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
443        (a) It was defining its arguments as char * instead of void *.
445        (b) It was assuming that all moves were upwards in memory; this was true
446            a long time ago when I wrote it, but is no longer the case.
448        The emulated memove() is provided for those environments that have neither
449        memmove() nor bcopy(). I didn't think anyone used it these days, but that
450        is clearly not the case, as these two bugs were recently reported.
452    11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
453        and Detrail to create the HTML documentation, the .txt form of the man
454        pages, and it removes trailing spaces from listed files. It also creates
455        pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
456        case, it wraps all the #defines with #ifndefs. This script should be run
457        before "make dist".
459    12. Fixed two fairly obscure bugs concerned with quantified caseless matching
460        with Unicode property support.
462        (a) For a maximizing quantifier, if the two different cases of the
463            character were of different lengths in their UTF-8 codings (there are
464            some cases like this - I found 11), and the matching function had to
465            back up over a mixture of the two cases, it incorrectly assumed they
466            were both the same length.
468        (b) When PCRE was configured to use the heap rather than the stack for
469            recursion during matching, it was not correctly preserving the data for
470            the other case of a UTF-8 character when checking ahead for a match
471            while processing a minimizing repeat. If the check also involved
472            matching a wide character, but failed, corruption could cause an
473            erroneous result when trying to check for a repeat of the original
474            character.
476    13. Some tidying changes to the testing mechanism:
478        (a) The RunTest script now detects the internal link size and whether there
479            is UTF-8 and UCP support by running ./pcretest -C instead of relying on
480            values substituted by "configure". (The RunGrepTest script already did
481            this for UTF-8.) The configure.ac script no longer substitutes the
482            relevant variables.
484        (b) The debugging options /B and /D in pcretest show the compiled bytecode
485            with length and offset values. This means that the output is different
486            for different internal link sizes. Test 2 is skipped for link sizes
487            other than 2 because of this, bypassing the problem. Unfortunately,
488            there was also a test in test 3 (the locale tests) that used /B and
489            failed for link sizes other than 2. Rather than cut the whole test out,
490            I have added a new /Z option to pcretest that replaces the length and
491            offset values with spaces. This is now used to make test 3 independent
492            of link size. (Test 2 will be tidied up later.)
494    14. If erroroffset was passed as NULL to pcre_compile, it provoked a
495        segmentation fault instead of returning the appropriate error message.
497    15. In multiline mode when the newline sequence was set to "any", the pattern
498        ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
499        This doesn't seem right; it now treats the CRLF combination as the line
500        ending, and so does not match in that case. It's only a pattern such as ^$
501        that would hit this one: something like ^ABC$ would have failed after \r
502        and then tried again after \r\n.
504    16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
505        in an attempt to make files that differ only in their line terminators
506        compare equal. This works on Linux.
508    17. Under certain error circumstances pcregrep might try to free random memory
509        as it exited. This is now fixed, thanks to valgrind.
511    19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
512        "abc\r\n\r\n", it found an unwanted second match after the second \r. This
513        was because its rules for how to advance for /g after matching an empty
514        string at the end of a line did not allow for this case. They now check for
515        it specially.
517    20. pcretest is supposed to handle patterns and data of any length, by
518        extending its buffers when necessary. It was getting this wrong when the
519        buffer for a data line had to be extended.
521    21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
522        CRLF as a newline sequence.
524    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
525        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
526        I have nevertheless tidied it up.
528    23. Added some casts to kill warnings from HP-UX ia64 compiler.
530    24. Added a man page for pcre-config.
533  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
534  ---------------------  ---------------------

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