ICE on compare of this pointer with reference and throw

[Diederik]

When compiling the code attached (Note: it has a Qt dependency) the compiler crashes with the following output:
$ make
g++ -c -pipe -g -Wall -W -D_REENTRANT -DQT_WEBKIT -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o test2.o test2.cpp
test2.cpp:19:5: warning: unused parameter ‘argc’ [-Wunused-parameter]
test2.cpp:19:5: warning: unused parameter ‘arcv’ [-Wunused-parameter]
test2.cpp: In constructor ‘CompareThisRefICE::CompareThisRefICE()’:
test2.cpp:9:1: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.6/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccjiYBA.out file, please attach this to your bugreport.
make: *** [test2.o] Error 1

Was reproduced with Qt 4.5.2 and Qt 4.7.4 on gcc (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1

I recently upgraded to Ubuntu 11.10.

uname -a gives
Linux djh-emssnew 3.0.0-12-generic-pae #20-Ubuntu SMP Fri Oct 7 16:37:17 UTC 2011 i686 i686 i386 GNU/Linux

[Djh (djh)]

Created attachment 25624
Program that causes ICE

When compiling the code attached (Note: it has a Qt dependency (sorry) ) the compiler crashes with the following output:
$ make
g++ -c -pipe -g -Wall -W -D_REENTRANT -DQT_WEBKIT -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -o test2.o test2.cpp
test2.cpp:19:5: warning: unused parameter ‘argc’ [-Wunused-parameter]
test2.cpp:19:5: warning: unused parameter ‘arcv’ [-Wunused-parameter]
test2.cpp: In constructor ‘CompareThisRefICE::CompareThisRefICE()’:
test2.cpp:9:1: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.6/README.Bugs> for instructions.
Preprocessed source stored into /tmp/ccjiYBA.out file, please attach this to your bugreport.
make: *** [test2.o] Error 1

Was reproduced with Qt 4.5.2 and Qt 4.7.4 on gcc (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1

I recently upgraded to Ubuntu 11.10.

uname -a
Linux djh-emssnew 3.0.0-12-generic-pae #20-Ubuntu SMP Fri Oct 7 16:37:17 UTC 2011 i686 i686 i386 GNU/Linux

gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/4.6.1/lto-wrapper
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.1-9ubuntu3' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3)

I have logged it with Ubuntu first (https://bugs.launchpad.net/ubuntu/+source/gcc-4.6/+bug/877431) but no activity for more than a week.

[Rguenth (rguenth)]

Please proide preprocessed source of the file that produces this ICE.

[Djh (djh)]

In the archive, see the file ccjiYBAm.out
If this is not sufficient, I can upload a new one.

[Redi (redi)]

That file is sufficient, but please attach it separately (the instructions at http://gcc.gnu.org/bugs/ are pretty clear about wanting preprocessed source not an archive that we need to extract to find the right file).

N.B. preprocessed C++ source should use the extension .ii so GCC knows what to do with it, see http://gcc.gnu.org/onlinedocs/gcc/Overall-Options.html - if you use -save-temps as suggested at http://gcc.gnu.org/bugs/ then that file is created automatically

[Djh (djh)]

Created attachment 25626
Preprocessed source file

Preprocessed file attached as requested.

[Paolo-carlini (paolo-carlini)]

Richard I just checked the preprocessed (on x86_64 -m32) and apparently mainline is Ok, 4_6-branch Seg Faults at tree-cfg.c:1083, I'm not sure it's a C++ issue.

[Paolo-carlini (paolo-carlini)]

Oops.

[Diederik (diederikjhattingh)]

Logged with GCC at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50881

[Rguenth (rguenth)]

We have corrupt EH info during cfgcleaup right before expand. Reducing.

[Rguenth (rguenth)]

Reduced testcase:

class CompareThisRefICE {
    CompareThisRefICE();
};
typedef unsigned short ushort;
class __attribute__((visibility("default"))) QString {
public:
    ~QString();
    inline QString(const char *ch) : d(fromAscii_helper(ch)) { }
    struct Data { ushort righttoleft : 11; };
    Data *d;
    static Data *fromAscii_helper(const char *str, int size = -1);
};
class B { };
CompareThisRefICE::CompareThisRefICE() {
    CompareThisRefICE t;
    if (!(this != &t)) {
        QString b("boom");
        throw B();
    }
}

[Jakub-gcc (jakub-gcc)]

GCC 4.6.3 is being released.