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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 7.1 12-Mar-07  Version 7.6 19-Jan-08
5    ---------------------
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.
11    2.  Patch to cut out the "long long" test in pcrecpp_unittest when
12        HAVE_LONG_LONG is not defined.
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:
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.
27    Version 7.5 10-Jan-08
28    ---------------------
30    1.  Applied a patch from Craig: "This patch makes it possible to 'ignore'
31        values in parens when parsing an RE using the C++ wrapper."
33    2.  Negative specials like \S did not work in character classes in UTF-8 mode.
34        Characters greater than 255 were excluded from the class instead of being
35        included.
37    3.  The same bug as (2) above applied to negated POSIX classes such as
38        [:^space:].
40    4.  PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
41        defined or documented. It seems to have been a typo for PCRE_STATIC, so
42        I have changed it.
44    5.  The construct (?&) was not diagnosed as a syntax error (it referenced the
45        first named subpattern) and a construct such as (?&a) would reference the
46        first named subpattern whose name started with "a" (in other words, the
47        length check was missing). Both these problems are fixed. "Subpattern name
48        expected" is now given for (?&) (a zero-length name), and this patch also
49        makes it give the same error for \k'' (previously it complained that that
50        was a reference to a non-existent subpattern).
52    6.  The erroneous patterns (?+-a) and (?-+a) give different error messages;
53        this is right because (?- can be followed by option settings as well as by
54        digits. I have, however, made the messages clearer.
56    7.  Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
57        than the number used in the conditional) now cause a compile-time error.
58        This is actually not compatible with Perl, which accepts such patterns, but
59        treats the conditional as always being FALSE (as PCRE used to), but it
60        seems to me that giving a diagnostic is better.
62    8.  Change "alphameric" to the more common word "alphanumeric" in comments
63        and messages.
65    9.  Fix two occurrences of "backslash" in comments that should have been
66        "backspace".
68    10. Remove two redundant lines of code that can never be obeyed (their function
69        was moved elsewhere).
71    11. The program that makes PCRE's Unicode character property table had a bug
72        which caused it to generate incorrect table entries for sequences of
73        characters that have the same character type, but are in different scripts.
74        It amalgamated them into a single range, with the script of the first of
75        them. In other words, some characters were in the wrong script. There were
76        thirteen such cases, affecting characters in the following ranges:
78          U+002b0 - U+002c1
79          U+0060c - U+0060d
80          U+0061e - U+00612
81          U+0064b - U+0065e
82          U+0074d - U+0076d
83          U+01800 - U+01805
84          U+01d00 - U+01d77
85          U+01d9b - U+01dbf
86          U+0200b - U+0200f
87          U+030fc - U+030fe
88          U+03260 - U+0327f
89          U+0fb46 - U+0fbb1
90          U+10450 - U+1049d
92    12. The -o option (show only the matching part of a line) for pcregrep was not
93        compatible with GNU grep in that, if there was more than one match in a
94        line, it showed only the first of them. It now behaves in the same way as
95        GNU grep.
97    13. If the -o and -v options were combined for pcregrep, it printed a blank
98        line for every non-matching line. GNU grep prints nothing, and pcregrep now
99        does the same. The return code can be used to tell if there were any
100        non-matching lines.
102    14. Added --file-offsets and --line-offsets to pcregrep.
104    15. The pattern (?=something)(?R) was not being diagnosed as a potentially
105        infinitely looping recursion. The bug was that positive lookaheads were not
106        being skipped when checking for a possible empty match (negative lookaheads
107        and both kinds of lookbehind were skipped).
109    16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
110        inclusion of <windows.h> to before rather than after the definition of
111        INVALID_FILE_ATTRIBUTES (patch from David Byron).
113    17. Specifying a possessive quantifier with a specific limit for a Unicode
114        character property caused pcre_compile() to compile bad code, which led at
115        runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
116        are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
117        caused the error; without that there was no problem.
119    18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
121    19. Added --enable-pcretest-libreadline.
123    20. In pcrecpp.cc, the variable 'count' was incremented twice in
124        RE::GlobalReplace(). As a result, the number of replacements returned was
125        double what it should be. I removed one of the increments, but Craig sent a
126        later patch that removed the other one (the right fix) and added unit tests
127        that check the return values (which was not done before).
129    21. Several CMake things:
131        (1) Arranged that, when cmake is used on Unix, the libraries end up with
132            the names libpcre and libpcreposix, not just pcre and pcreposix.
134        (2) The above change means that pcretest and pcregrep are now correctly
135            linked with the newly-built libraries, not previously installed ones.
139    22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
140        crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
141        UTF-8 newline character). The key issue is that the pattern starts .*;
142        this means that the match must be either at the beginning, or after a
143        newline. The bug was in the code for advancing after a failed match and
144        checking that the new position followed a newline. It was not taking
145        account of UTF-8 characters correctly.
147    23. PCRE was behaving differently from Perl in the way it recognized POSIX
148        character classes. PCRE was not treating the sequence [:...:] as a
149        character class unless the ... were all letters. Perl, however, seems to
150        allow any characters between [: and :], though of course it rejects as
151        unknown any "names" that contain non-letters, because all the known class
152        names consist only of letters. Thus, Perl gives an error for [[:1234:]],
153        for example, whereas PCRE did not - it did not recognize a POSIX character
154        class. This seemed a bit dangerous, so the code has been changed to be
155        closer to Perl. The behaviour is not identical to Perl, because PCRE will
156        diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
157        treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
158        Perl does, and where it didn't before.
160    24. Rewrite so as to remove the single use of %n from pcregrep because in some
161        Windows environments %n is disabled by default.
164    Version 7.4 21-Sep-07
165    ---------------------
167    1.  Change 7.3/28 was implemented for classes by looking at the bitmap. This
168        means that a class such as [\s] counted as "explicit reference to CR or
169        LF". That isn't really right - the whole point of the change was to try to
170        help when there was an actual mention of one of the two characters. So now
171        the change happens only if \r or \n (or a literal CR or LF) character is
172        encountered.
174    2.  The 32-bit options word was also used for 6 internal flags, but the numbers
175        of both had grown to the point where there were only 3 bits left.
176        Fortunately, there was spare space in the data structure, and so I have
177        moved the internal flags into a new 16-bit field to free up more option
178        bits.
180    3.  The appearance of (?J) at the start of a pattern set the DUPNAMES option,
181        but did not set the internal JCHANGED flag - either of these is enough to
182        control the way the "get" function works - but the PCRE_INFO_JCHANGED
183        facility is supposed to tell if (?J) was ever used, so now (?J) at the
184        start sets both bits.
186    4.  Added options (at build time, compile time, exec time) to change \R from
187        matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
189    5.  doc/pcresyntax.html was missing from the distribution.
191    6.  Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
192        compatibility, even though it is no longer used.
194    7.  Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
195        strtoull to pcrecpp.cc to select the available functions in WIN32 when the
196        windows.h file is present (where different names are used). [This was
197        reversed later after testing - see 16 below.]
199    8.  Changed all #include <config.h> to #include "config.h". There were also
200        some further <pcre.h> cases that I changed to "pcre.h".
202    9.  When pcregrep was used with the --colour option, it missed the line ending
203        sequence off the lines that it output.
205    10. It was pointed out to me that arrays of string pointers cause lots of
206        relocations when a shared library is dynamically loaded. A technique of
207        using a single long string with a table of offsets can drastically reduce
208        these. I have refactored PCRE in four places to do this. The result is
209        dramatic:
211          Originally:                          290
212          After changing UCP table:            187
213          After changing error message table:   43
214          After changing table of "verbs"       36
215          After changing table of Posix names   22
217        Thanks to the folks working on Gregex for glib for this insight.
219    11. --disable-stack-for-recursion caused compiling to fail unless -enable-
220        unicode-properties was also set.
222    12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
224    13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
225        checked only for CRLF.
227    14. Added casts to pcretest.c to avoid compiler warnings.
229    15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
231    16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
232        and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
233        entirely. This removes changes made in 7 above.
235    17. The CMake files have been updated, and there is now more information about
236        building with CMake in the NON-UNIX-USE document.
239    Version 7.3 28-Aug-07
240    ---------------------
242     1. In the rejigging of the build system that eventually resulted in 7.1, the
243        line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
244        brackets there is not right, since it causes compilers to look for an
245        installed pcre.h, not the version that is in the source that is being
246        compiled (which of course may be different). I have changed it back to:
248          #include "pcre.h"
250        I have a vague recollection that the change was concerned with compiling in
251        different directories, but in the new build system, that is taken care of
252        by the VPATH setting the Makefile.
254     2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
255        when the subject happened to end in the byte 0x85 (e.g. if the last
256        character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
257        characters but of course it shouldn't be taken as a newline when it is part
258        of another character. The bug was that, for an unlimited repeat of . in
259        not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
260        characters when looking for a newline.
262     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
264     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
265        in debug output.
267     5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
268        long printing in the pcrecpp unittest when running under MinGW.
270     6. ESC_K was left out of the EBCDIC table.
272     7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
273        parentheses; I made it 1000, which seemed large enough. Unfortunately, the
274        limit also applies to "virtual nesting" when a pattern is recursive, and in
275        this case 1000 isn't so big. I have been able to remove this limit at the
276        expense of backing off one optimization in certain circumstances. Normally,
277        when pcre_exec() would call its internal match() function recursively and
278        immediately return the result unconditionally, it uses a "tail recursion"
279        feature to save stack. However, when a subpattern that can match an empty
280        string has an unlimited repetition quantifier, it no longer makes this
281        optimization. That gives it a stack frame in which to save the data for
282        checking that an empty string has been matched. Previously this was taken
283        from the 1000-entry workspace that had been reserved. So now there is no
284        explicit limit, but more stack is used.
286     8. Applied Daniel's patches to solve problems with the import/export magic
287        syntax that is required for Windows, and which was going wrong for the
288        pcreposix and pcrecpp parts of the library. These were overlooked when this
289        problem was solved for the main library.
291     9. There were some crude static tests to avoid integer overflow when computing
292        the size of patterns that contain repeated groups with explicit upper
293        limits. As the maximum quantifier is 65535, the maximum group length was
294        set at 30,000 so that the product of these two numbers did not overflow a
295        32-bit integer. However, it turns out that people want to use groups that
296        are longer than 30,000 bytes (though not repeat them that many times).
297        Change 7.0/17 (the refactoring of the way the pattern size is computed) has
298        made it possible to implement the integer overflow checks in a much more
299        dynamic way, which I have now done. The artificial limitation on group
300        length has been removed - we now have only the limit on the total length of
301        the compiled pattern, which depends on the LINK_SIZE setting.
303    10. Fixed a bug in the documentation for get/copy named substring when
304        duplicate names are permitted. If none of the named substrings are set, the
305        functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
306        empty string.
308    11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
309        instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
310        because the ] is interpreted as the first data character and the
311        terminating ] is not found. PCRE has been made compatible with Perl in this
312        regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
313        cause memory overwriting.
315    10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
316        string has been matched (to stop an infinite loop). It was not recognizing
317        a conditional subpattern that could match an empty string if that
318        subpattern was within another subpattern. For example, it looped when
319        trying to match  (((?(1)X|))*)  but it was OK with  ((?(1)X|)*)  where the
320        condition was not nested. This bug has been fixed.
322    12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
323        past the start of the subject in the presence of bytes with the top bit
324        set, for example "\x8aBCD".
326    13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
327        (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
329    14. Optimized (?!) to (*FAIL).
331    15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
332        This restricts code points to be within the range 0 to 0x10FFFF, excluding
333        the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
334        full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
335        does: it's just the validity check that is more restrictive.
337    16. Inserted checks for integer overflows during escape sequence (backslash)
338        processing, and also fixed erroneous offset values for syntax errors during
339        backslash processing.
341    17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
342        for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
344    18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
345        caused an overrun.
347    19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
348        something other than just ASCII characters) inside a group that had an
349        unlimited repeat caused a loop at compile time (while checking to see
350        whether the group could match an empty string).
352    20. Debugging a pattern containing \p or \P could cause a crash. For example,
353        [\P{Any}] did so. (Error in the code for printing property names.)
355    21. An orphan \E inside a character class could cause a crash.
357    22. A repeated capturing bracket such as (A)? could cause a wild memory
358        reference during compilation.
360    23. There are several functions in pcre_compile() that scan along a compiled
361        expression for various reasons (e.g. to see if it's fixed length for look
362        behind). There were bugs in these functions when a repeated \p or \P was
363        present in the pattern. These operators have additional parameters compared
364        with \d, etc, and these were not being taken into account when moving along
365        the compiled data. Specifically:
367        (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
368            length.
370        (b) An item such as \pL+ within a repeated group could cause crashes or
371            loops.
373        (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
374            "reference to non-existent subpattern" error.
376        (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
378    24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
379        characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
381    25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
383    26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
384        character were causing crashes (broken optimization).
386    27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
387        \p or \P) caused a compile-time loop.
389    28. More problems have arisen in unanchored patterns when CRLF is a valid line
390        break. For example, the unstudied pattern [\r\n]A does not match the string
391        "\r\nA" because change 7.0/46 below moves the current point on by two
392        characters after failing to match at the start. However, the pattern \nA
393        *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
394        the same is true. There doesn't seem any very clean way out of this, but
395        what I have chosen to do makes the common cases work: PCRE now takes note
396        of whether there can be an explicit match for \r or \n anywhere in the
397        pattern, and if so, 7.0/46 no longer applies. As part of this change,
398        there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
399        pattern has explicit CR or LF references.
401    29. Added (*CR) etc for changing newline setting at start of pattern.
404    Version 7.2 19-Jun-07
405    ---------------------
407     1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
408        which is apparently normally available under Windows.
410     2. Re-jig the pcregrep tests with different newline settings in an attempt
411        to make them independent of the local environment's newline setting.
413     3. Add code to configure.ac to remove -g from the CFLAGS default settings.
415     4. Some of the "internals" tests were previously cut out when the link size
416        was not 2, because the output contained actual offsets. The recent new
417        "Z" feature of pcretest means that these can be cut out, making the tests
418        usable with all link sizes.
420     5. Implemented Stan Switzer's goto replacement for longjmp() when not using
421        stack recursion. This gives a massive performance boost under BSD, but just
422        a small improvement under Linux. However, it saves one field in the frame
423        in all cases.
425     6. Added more features from the forthcoming Perl 5.10:
427        (a) (?-n) (where n is a string of digits) is a relative subroutine or
428            recursion call. It refers to the nth most recently opened parentheses.
430        (b) (?+n) is also a relative subroutine call; it refers to the nth next
431            to be opened parentheses.
433        (c) Conditions that refer to capturing parentheses can be specified
434            relatively, for example, (?(-2)... or (?(+3)...
436        (d) \K resets the start of the current match so that everything before
437            is not part of it.
439        (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
441        (f) \g{name} is another synonym - part of Perl 5.10's unification of
442            reference syntax.
444        (g) (?| introduces a group in which the numbering of parentheses in each
445            alternative starts with the same number.
447        (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
449     7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
452     8. A pattern such as  (.*(.)?)*  caused pcre_exec() to fail by either not
453        terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
454        for detecting groups that can match an empty string.
456     9. A pattern with a very large number of alternatives (more than several
457        hundred) was running out of internal workspace during the pre-compile
458        phase, where pcre_compile() figures out how much memory will be needed. A
459        bit of new cunning has reduced the workspace needed for groups with
460        alternatives. The 1000-alternative test pattern now uses 12 bytes of
461        workspace instead of running out of the 4096 that are available.
463    10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
465    11. Applied patch from Google to remove an optimization that didn't quite work.
466        The report of the bug said:
468          pcrecpp::RE("a*").FullMatch("aaa") matches, while
469          pcrecpp::RE("a*?").FullMatch("aaa") does not, and
470          pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
472    12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
473        it matched the wrong number of bytes.
476    Version 7.1 24-Apr-07
477  ---------------------  ---------------------
479   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 135  Version 7.1 12-Mar-07 Line 607  Version 7.1 12-Mar-07
607      was because its rules for how to advance for /g after matching an empty      was because its rules for how to advance for /g after matching an empty
608      string at the end of a line did not allow for this case. They now check for      string at the end of a line did not allow for this case. They now check for
609      it specially.      it specially.
611  20. pcretest is supposed to handle patterns and data of any length, by  20. pcretest is supposed to handle patterns and data of any length, by
612      extending its buffers when necessary. It was getting this wrong when the      extending its buffers when necessary. It was getting this wrong when the
613      buffer for a data line had to be extended.      buffer for a data line had to be extended.
615  21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or  21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
616      CRLF as a newline sequence.      CRLF as a newline sequence.
618    22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
619        out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
620        I have nevertheless tidied it up.
622    23. Added some casts to kill warnings from HP-UX ia64 compiler.
624    24. Added a man page for pcre-config.
627  Version 7.0 19-Dec-06  Version 7.0 19-Dec-06

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