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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
3    
4  Version 7.1 12-Mar-07  Version 7.6 19-Jan-08
5    ---------------------
6    
7    1.  A character class containing a very large number of characters with
8        codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
9        overflow.
10    
11    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
12        HAVE_LONG_LONG is not defined.
13    
14    3.  Applied Christian Ehrlicher's patch to update the CMake build files to
15        bring them up to date and include new features. This patch includes:
16    
17        - Fixed PH's badly added libz and libbz2 support.
18        - Fixed a problem with static linking.
19        - Added pcredemo.
20        - Fixed dftables problem and added an option.
21        - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
22            HAVE_LONG_LONG.
23        - Added readline support for pcretest.
24        - Added an listing of the option settings after cmake has run.
25    
26    4.  A user submitted a patch to Makefile that makes it easy to created a dll
27        under mingw. I added stuff to Makefile.am that cause it to include this
28        special target, without affecting anything else.
29    
30    5.  Applied Craig's patch that moves no_arg into the RE class in the C++ code.
31        This is an attempt to solve the reported problem "pcrecpp::no_arg is not
32        exported in the Windows port". It has not yet been confirmed that the patch
33        solves the problem, but it does no harm.
34    
35    
36    Version 7.5 10-Jan-08
37    ---------------------
38    
39    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
40        values in parens when parsing an RE using the C++ wrapper."
41    
42    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
43        Characters greater than 255 were excluded from the class instead of being
44        included.
45    
46    3.  The same bug as (2) above applied to negated POSIX classes such as
47        [:^space:].
48    
49    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
50        defined or documented. It seems to have been a typo for PCRE_STATIC, so
51        I have changed it.
52    
53    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
54        first named subpattern) and a construct such as (?&a) would reference the
55        first named subpattern whose name started with "a" (in other words, the
56        length check was missing). Both these problems are fixed. "Subpattern name
57        expected" is now given for (?&) (a zero-length name), and this patch also
58        makes it give the same error for \k'' (previously it complained that that
59        was a reference to a non-existent subpattern).
60    
61    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
62        this is right because (?- can be followed by option settings as well as by
63        digits. I have, however, made the messages clearer.
64    
65    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
66        than the number used in the conditional) now cause a compile-time error.
67        This is actually not compatible with Perl, which accepts such patterns, but
68        treats the conditional as always being FALSE (as PCRE used to), but it
69        seems to me that giving a diagnostic is better.
70    
71    8.  Change "alphameric" to the more common word "alphanumeric" in comments
72        and messages.
73    
74    9.  Fix two occurrences of "backslash" in comments that should have been
75        "backspace".
76    
77    10. Remove two redundant lines of code that can never be obeyed (their function
78        was moved elsewhere).
79    
80    11. The program that makes PCRE's Unicode character property table had a bug
81        which caused it to generate incorrect table entries for sequences of
82        characters that have the same character type, but are in different scripts.
83        It amalgamated them into a single range, with the script of the first of
84        them. In other words, some characters were in the wrong script. There were
85        thirteen such cases, affecting characters in the following ranges:
86    
87          U+002b0 - U+002c1
88          U+0060c - U+0060d
89          U+0061e - U+00612
90          U+0064b - U+0065e
91          U+0074d - U+0076d
92          U+01800 - U+01805
93          U+01d00 - U+01d77
94          U+01d9b - U+01dbf
95          U+0200b - U+0200f
96          U+030fc - U+030fe
97          U+03260 - U+0327f
98          U+0fb46 - U+0fbb1
99          U+10450 - U+1049d
100    
101    12. The -o option (show only the matching part of a line) for pcregrep was not
102        compatible with GNU grep in that, if there was more than one match in a
103        line, it showed only the first of them. It now behaves in the same way as
104        GNU grep.
105    
106    13. If the -o and -v options were combined for pcregrep, it printed a blank
107        line for every non-matching line. GNU grep prints nothing, and pcregrep now
108        does the same. The return code can be used to tell if there were any
109        non-matching lines.
110    
111    14. Added --file-offsets and --line-offsets to pcregrep.
112    
113    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
114        infinitely looping recursion. The bug was that positive lookaheads were not
115        being skipped when checking for a possible empty match (negative lookaheads
116        and both kinds of lookbehind were skipped).
117    
118    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
119        inclusion of <windows.h> to before rather than after the definition of
120        INVALID_FILE_ATTRIBUTES (patch from David Byron).
121    
122    17. Specifying a possessive quantifier with a specific limit for a Unicode
123        character property caused pcre_compile() to compile bad code, which led at
124        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
125        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
126        caused the error; without that there was no problem.
127    
128    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
129    
130    19. Added --enable-pcretest-libreadline.
131    
132    20. In pcrecpp.cc, the variable 'count' was incremented twice in
133        RE::GlobalReplace(). As a result, the number of replacements returned was
134        double what it should be. I removed one of the increments, but Craig sent a
135        later patch that removed the other one (the right fix) and added unit tests
136        that check the return values (which was not done before).
137    
138    21. Several CMake things:
139    
140        (1) Arranged that, when cmake is used on Unix, the libraries end up with
141            the names libpcre and libpcreposix, not just pcre and pcreposix.
142    
143        (2) The above change means that pcretest and pcregrep are now correctly
144            linked with the newly-built libraries, not previously installed ones.
145    
146        (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
147    
148    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
149        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
150        UTF-8 newline character). The key issue is that the pattern starts .*;
151        this means that the match must be either at the beginning, or after a
152        newline. The bug was in the code for advancing after a failed match and
153        checking that the new position followed a newline. It was not taking
154        account of UTF-8 characters correctly.
155    
156    23. PCRE was behaving differently from Perl in the way it recognized POSIX
157        character classes. PCRE was not treating the sequence [:...:] as a
158        character class unless the ... were all letters. Perl, however, seems to
159        allow any characters between [: and :], though of course it rejects as
160        unknown any "names" that contain non-letters, because all the known class
161        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
162        for example, whereas PCRE did not - it did not recognize a POSIX character
163        class. This seemed a bit dangerous, so the code has been changed to be
164        closer to Perl. The behaviour is not identical to Perl, because PCRE will
165        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
166        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
167        Perl does, and where it didn't before.
168    
169    24. Rewrite so as to remove the single use of %n from pcregrep because in some
170        Windows environments %n is disabled by default.
171    
172    
173    Version 7.4 21-Sep-07
174    ---------------------
175    
176    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
177        means that a class such as [\s] counted as "explicit reference to CR or
178        LF". That isn't really right - the whole point of the change was to try to
179        help when there was an actual mention of one of the two characters. So now
180        the change happens only if \r or \n (or a literal CR or LF) character is
181        encountered.
182    
183    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
184        of both had grown to the point where there were only 3 bits left.
185        Fortunately, there was spare space in the data structure, and so I have
186        moved the internal flags into a new 16-bit field to free up more option
187        bits.
188    
189    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
190        but did not set the internal JCHANGED flag - either of these is enough to
191        control the way the "get" function works - but the PCRE_INFO_JCHANGED
192        facility is supposed to tell if (?J) was ever used, so now (?J) at the
193        start sets both bits.
194    
195    4.  Added options (at build time, compile time, exec time) to change \R from
196        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
197    
198    5.  doc/pcresyntax.html was missing from the distribution.
199    
200    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
201        compatibility, even though it is no longer used.
202    
203    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
204        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
205        windows.h file is present (where different names are used). [This was
206        reversed later after testing - see 16 below.]
207    
208    8.  Changed all #include <config.h> to #include "config.h". There were also
209        some further <pcre.h> cases that I changed to "pcre.h".
210    
211    9.  When pcregrep was used with the --colour option, it missed the line ending
212        sequence off the lines that it output.
213    
214    10. It was pointed out to me that arrays of string pointers cause lots of
215        relocations when a shared library is dynamically loaded. A technique of
216        using a single long string with a table of offsets can drastically reduce
217        these. I have refactored PCRE in four places to do this. The result is
218        dramatic:
219    
220          Originally:                          290
221          After changing UCP table:            187
222          After changing error message table:   43
223          After changing table of "verbs"       36
224          After changing table of Posix names   22
225    
226        Thanks to the folks working on Gregex for glib for this insight.
227    
228    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
229        unicode-properties was also set.
230    
231    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
232    
233    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
234        checked only for CRLF.
235    
236    14. Added casts to pcretest.c to avoid compiler warnings.
237    
238    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
239    
240    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
241        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
242        entirely. This removes changes made in 7 above.
243    
244    17. The CMake files have been updated, and there is now more information about
245        building with CMake in the NON-UNIX-USE document.
246    
247    
248    Version 7.3 28-Aug-07
249    ---------------------
250    
251     1. In the rejigging of the build system that eventually resulted in 7.1, the
252        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
253        brackets there is not right, since it causes compilers to look for an
254        installed pcre.h, not the version that is in the source that is being
255        compiled (which of course may be different). I have changed it back to:
256    
257          #include "pcre.h"
258    
259        I have a vague recollection that the change was concerned with compiling in
260        different directories, but in the new build system, that is taken care of
261        by the VPATH setting the Makefile.
262    
263     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
264        when the subject happened to end in the byte 0x85 (e.g. if the last
265        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
266        characters but of course it shouldn't be taken as a newline when it is part
267        of another character. The bug was that, for an unlimited repeat of . in
268        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
269        characters when looking for a newline.
270    
271     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
272    
273     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
274        in debug output.
275    
276     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
277        long printing in the pcrecpp unittest when running under MinGW.
278    
279     6. ESC_K was left out of the EBCDIC table.
280    
281     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
282        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
283        limit also applies to "virtual nesting" when a pattern is recursive, and in
284        this case 1000 isn't so big. I have been able to remove this limit at the
285        expense of backing off one optimization in certain circumstances. Normally,
286        when pcre_exec() would call its internal match() function recursively and
287        immediately return the result unconditionally, it uses a "tail recursion"
288        feature to save stack. However, when a subpattern that can match an empty
289        string has an unlimited repetition quantifier, it no longer makes this
290        optimization. That gives it a stack frame in which to save the data for
291        checking that an empty string has been matched. Previously this was taken
292        from the 1000-entry workspace that had been reserved. So now there is no
293        explicit limit, but more stack is used.
294    
295     8. Applied Daniel's patches to solve problems with the import/export magic
296        syntax that is required for Windows, and which was going wrong for the
297        pcreposix and pcrecpp parts of the library. These were overlooked when this
298        problem was solved for the main library.
299    
300     9. There were some crude static tests to avoid integer overflow when computing
301        the size of patterns that contain repeated groups with explicit upper
302        limits. As the maximum quantifier is 65535, the maximum group length was
303        set at 30,000 so that the product of these two numbers did not overflow a
304        32-bit integer. However, it turns out that people want to use groups that
305        are longer than 30,000 bytes (though not repeat them that many times).
306        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
307        made it possible to implement the integer overflow checks in a much more
308        dynamic way, which I have now done. The artificial limitation on group
309        length has been removed - we now have only the limit on the total length of
310        the compiled pattern, which depends on the LINK_SIZE setting.
311    
312    10. Fixed a bug in the documentation for get/copy named substring when
313        duplicate names are permitted. If none of the named substrings are set, the
314        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
315        empty string.
316    
317    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
318        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
319        because the ] is interpreted as the first data character and the
320        terminating ] is not found. PCRE has been made compatible with Perl in this
321        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
322        cause memory overwriting.
323    
324    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
325        string has been matched (to stop an infinite loop). It was not recognizing
326        a conditional subpattern that could match an empty string if that
327        subpattern was within another subpattern. For example, it looped when
328        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
329        condition was not nested. This bug has been fixed.
330    
331    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
332        past the start of the subject in the presence of bytes with the top bit
333        set, for example "\x8aBCD".
334    
335    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
336        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
337    
338    14. Optimized (?!) to (*FAIL).
339    
340    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
341        This restricts code points to be within the range 0 to 0x10FFFF, excluding
342        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
343        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
344        does: it's just the validity check that is more restrictive.
345    
346    16. Inserted checks for integer overflows during escape sequence (backslash)
347        processing, and also fixed erroneous offset values for syntax errors during
348        backslash processing.
349    
350    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
351        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
352    
353    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
354        caused an overrun.
355    
356    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
357        something other than just ASCII characters) inside a group that had an
358        unlimited repeat caused a loop at compile time (while checking to see
359        whether the group could match an empty string).
360    
361    20. Debugging a pattern containing \p or \P could cause a crash. For example,
362        [\P{Any}] did so. (Error in the code for printing property names.)
363    
364    21. An orphan \E inside a character class could cause a crash.
365    
366    22. A repeated capturing bracket such as (A)? could cause a wild memory
367        reference during compilation.
368    
369    23. There are several functions in pcre_compile() that scan along a compiled
370        expression for various reasons (e.g. to see if it's fixed length for look
371        behind). There were bugs in these functions when a repeated \p or \P was
372        present in the pattern. These operators have additional parameters compared
373        with \d, etc, and these were not being taken into account when moving along
374        the compiled data. Specifically:
375    
376        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
377            length.
378    
379        (b) An item such as \pL+ within a repeated group could cause crashes or
380            loops.
381    
382        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
383            "reference to non-existent subpattern" error.
384    
385        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
386    
387    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
388        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
389    
390    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
391    
392    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
393        character were causing crashes (broken optimization).
394    
395    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
396        \p or \P) caused a compile-time loop.
397    
398    28. More problems have arisen in unanchored patterns when CRLF is a valid line
399        break. For example, the unstudied pattern [\r\n]A does not match the string
400        "\r\nA" because change 7.0/46 below moves the current point on by two
401        characters after failing to match at the start. However, the pattern \nA
402        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
403        the same is true. There doesn't seem any very clean way out of this, but
404        what I have chosen to do makes the common cases work: PCRE now takes note
405        of whether there can be an explicit match for \r or \n anywhere in the
406        pattern, and if so, 7.0/46 no longer applies. As part of this change,
407        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
408        pattern has explicit CR or LF references.
409    
410    29. Added (*CR) etc for changing newline setting at start of pattern.
411    
412    
413    Version 7.2 19-Jun-07
414    ---------------------
415    
416     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
417        which is apparently normally available under Windows.
418    
419     2. Re-jig the pcregrep tests with different newline settings in an attempt
420        to make them independent of the local environment's newline setting.
421    
422     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
423    
424     4. Some of the "internals" tests were previously cut out when the link size
425        was not 2, because the output contained actual offsets. The recent new
426        "Z" feature of pcretest means that these can be cut out, making the tests
427        usable with all link sizes.
428    
429     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
430        stack recursion. This gives a massive performance boost under BSD, but just
431        a small improvement under Linux. However, it saves one field in the frame
432        in all cases.
433    
434     6. Added more features from the forthcoming Perl 5.10:
435    
436        (a) (?-n) (where n is a string of digits) is a relative subroutine or
437            recursion call. It refers to the nth most recently opened parentheses.
438    
439        (b) (?+n) is also a relative subroutine call; it refers to the nth next
440            to be opened parentheses.
441    
442        (c) Conditions that refer to capturing parentheses can be specified
443            relatively, for example, (?(-2)... or (?(+3)...
444    
445        (d) \K resets the start of the current match so that everything before
446            is not part of it.
447    
448        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
449    
450        (f) \g{name} is another synonym - part of Perl 5.10's unification of
451            reference syntax.
452    
453        (g) (?| introduces a group in which the numbering of parentheses in each
454            alternative starts with the same number.
455    
456        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
457    
458     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
459        PCRE_INFO_JCHANGED.
460    
461     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
462        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
463        for detecting groups that can match an empty string.
464    
465     9. A pattern with a very large number of alternatives (more than several
466        hundred) was running out of internal workspace during the pre-compile
467        phase, where pcre_compile() figures out how much memory will be needed. A
468        bit of new cunning has reduced the workspace needed for groups with
469        alternatives. The 1000-alternative test pattern now uses 12 bytes of
470        workspace instead of running out of the 4096 that are available.
471    
472    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
473    
474    11. Applied patch from Google to remove an optimization that didn't quite work.
475        The report of the bug said:
476    
477          pcrecpp::RE("a*").FullMatch("aaa") matches, while
478          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
479          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
480    
481    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
482        it matched the wrong number of bytes.
483    
484    
485    Version 7.1 24-Apr-07
486  ---------------------  ---------------------
487    
488   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one   1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
# Line 149  Version 7.1 12-Mar-07 Line 630  Version 7.1 12-Mar-07
630    
631  23. Added some casts to kill warnings from HP-UX ia64 compiler.  23. Added some casts to kill warnings from HP-UX ia64 compiler.
632    
633    24. Added a man page for pcre-config.
634    
635    
636  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06
637  ---------------------  ---------------------

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