[Bug c++/48856] New: Crash when compiling certain source code with C++0x

[Bug c++/48856] New: Crash when compiling certain source code with C++0x

[thiago at kde dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

           Summary: Crash when compiling certain source code with C++0x
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: thiago@kde.org


GCC crashes when compiling the attached source file in C++0x mode.

Steps to Reproduce:
1. Compile the attached preprocessed source file (Copyright Nokia, LGPL 2.1)
with C++0x support. That is, run:
   g++ -std=c++0x qxmlschema.ii

This results in the following message:
====
In file included from
/home/tmacieir/src/troll/qt-main/src/xmlpatterns/parser/qmaintainingreader_p.h:226:0,
                 from
/home/tmacieir/src/troll/qt-main/src/xmlpatterns/schema/qxsdschemaparsercontext_p.h:55,
                 from
/home/tmacieir/src/troll/qt-main/src/xmlpatterns/schema/qxsdschemaparser_p.h:67,
                 from
/home/tmacieir/src/troll/qt-main/src/xmlpatterns/api/qxmlschema_p.h:62,
                 from
/home/tmacieir/src/troll/qt-main/src/xmlpatterns/api/qxmlschema.cpp:43:
/home/tmacieir/src/troll/qt-main/src/xmlpatterns/parser/qmaintainingreader.cpp:
In member function 'QXmlStreamReader::TokenType
QPatternist::MaintainingReader<TokenLookupClass, LookupKey>::readNext()':
/home/tmacieir/src/troll/qt-main/src/xmlpatterns/parser/qmaintainingreader.cpp:86:57:
internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://qa.mandriva.com/> for instructions.
====

I have looked at Mandriva patches to GCC 4.6 and they do not seem to be related
at all (nothing related to the C++ engine at all), so I believe this is a GCC
issue.

The compiler also crashes if I preprocess the sources without -std=c++0x but
compile with it. The crash happens with the exact same messages.

This crash was not present on GCC 4.5.3.

[Bug c++/48856] Crash when compiling certain source code with C++0x

[thiago at kde dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

--- Comment #1 from Thiago Macieira <thiago at kde dot org> 2011-05-03 16:31:38 UTC ---
Created attachment 24171
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24171
Preprocessed sources showing the error (gzipped)

[Bug c++/48856] Crash when compiling certain source code with C++0x

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-05-03 16:54:08 UTC ---
It would also be helpful to reduce the testcase:
http://gcc.gnu.org/bugs/minimize.html

[Bug c++/48856] Crash when compiling certain source code with C++0x

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-05-03 16:51:49 UTC ---
Severity should not be critical for any C++0x bug, it's an experimental feature
and noone is forced to use.

This doesn't crash for me with 4.6.0 on x86_64-linux, please provide the
information requested at http://gcc.gnu.org/bugs/

[Bug c++/48856] Crash when compiling certain source code with C++0x

[thiago at kde dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

--- Comment #4 from Thiago Macieira <thiago at kde dot org> 2011-05-03 17:20:13 UTC ---
Sorry, I forgot the information.

Version: 4.6.0
System: Linux 2.6.38, 32-bit
Command-line: g++ -std=c++0x qxmlschema.ii
GCC was configured with:
./configure --build=i586-mandriva-linux-gnu --prefix=/usr --exec-prefix=/usr
--bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share
--includedir=/usr/include --libdir=/usr/lib --libexecdir=/usr/lib
--localstatedir=/var --sharedstatedir=/usr/com --mandir=/usr/share/man
--infodir=/usr/share/info --x-includes=/usr/include --x-libraries=/usr/lib
--disable-libjava-multilib --with-java-home=/usr/lib/jvm/java-rpmbuild
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-java-awt=qt,gtk
--enable-gtk-cairo --with-cloog --with-ppl --enable-cloog-backend=ppl
--disable-libssp --disable-libunwind-exceptions --disable-werror
--enable-__cxa_atexit --enable-bootstrap --enable-checking=release
--enable-gnu-unique-object
--enable-languages=c,ada,c++,fortran,go,java,lto,objc,obj-c++
--enable-linker-build-id --enable-plugin --enable-shared --enable-threads=posix
--with-system-zlib --with-bugurl=https://qa.mandriva.com/ --with-tune=generic
--with-arch=i686 --host=i586-mandriva-linux-gnu
--target=i586-mandriva-linux-gnu

[Bug c++/48856] Crash when compiling certain source code with C++0x

[thiago at kde dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

--- Comment #5 from Thiago Macieira <thiago at kde dot org> 2011-05-03 17:21:09 UTC ---
To be exact on the version: gcc version 4.6.0 20110422 (prerelease) (GCC)

[Bug c++/48856] Crash when compiling certain source code with C++0x

[thiago at kde dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

--- Comment #6 from Thiago Macieira <thiago at kde dot org> 2011-05-03 17:42:02 UTC ---
(In reply to comment #3)
> It would also be helpful to reduce the testcase:
> http://gcc.gnu.org/bugs/minimize.html

Thanks for the suggestion. I can't promise I will have the time to do this
any-time soon. 

I'm hoping that the reason for a straight-out crash can be found easily :)

Hopefully this could help:
==11293== Invalid read of size 2
==11293==    at 0x816090E: convert_for_initialization (typeck.c:7410)
==11293==    by 0x81324B9: digest_init_r (typeck2.c:861)
==11293==    by 0x813306B: store_init_value (typeck2.c:674)
==11293==    by 0x81095C8: check_initializer (decl.c:5413)
==11293==    by 0x811029D: cp_finish_decl (decl.c:5881)
==11293==    by 0x814F79D: cp_parser_init_declarator (parser.c:14769)
==11293==    by 0x8156B6A: cp_parser_simple_declaration (parser.c:9709)
==11293==    by 0x8156D65: cp_parser_block_declaration (parser.c:9595)
==11293==    by 0x81577BE: cp_parser_declaration_statement (parser.c:9247)
==11293==    by 0x814BE19: cp_parser_statement (parser.c:8172)
==11293==    by 0x814C545: cp_parser_statement_seq_opt (parser.c:8431)
==11293==    by 0x814C5B8: cp_parser_compound_statement (parser.c:8385)
==11293==  Address 0x0 is not stack'd, malloc'd or (recently) free'd

Line where this fails:
7410      if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
7411           && TREE_CODE (type) != ARRAY_TYPE
7412           && (TREE_CODE (type) != REFERENCE_TYPE
7413               || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
7414          || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
7415              && (TREE_CODE (type) != REFERENCE_TYPE
7416                  || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
7417          || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)

[Bug c++/48856] Crash when compiling certain source code with C++0x

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2011.05.03 20:09:46
     Ever Confirmed|0                           |1

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-05-03 20:09:46 UTC ---
(In reply to comment #5)
> To be exact on the version: gcc version 4.6.0 20110422 (prerelease) (GCC)

4.6.0 was released on 20110325 so I don't know what that version is, and I
can't reproduce this on i686-pc-linux-gnu with a vanilla 4.6.0, or on x86_64
(using -m32 -std=c++0x) with Red Hat's 4.6.0-6.fc15 or a current 4.7 build.

Please try to reproduce with a FSF version or report this to Mandriva.

[Bug c++/48856] Crash when compiling certain source code with C++0x

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

--- Comment #8 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-04 11:08:30 UTC ---
Works for me with 4.6.0 and on the tip of the branch on x86_64 with -m32.

[Bug c++/48856] Crash when compiling certain source code with C++0x

[thiago at kde dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48856

Thiago Macieira <thiago at kde dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|                            |WORKSFORME

--- Comment #9 from Thiago Macieira <thiago at kde dot org> 2011-05-11 08:43:06 UTC ---
Sorry for the noise. An upgrade from Mandriva fixed the issue.