http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55870



             Bug #: 55870

           Summary: Compiler crash when template includes sizeof of

                    something that shouldn't be dereferenced

    Classification: Unclassified

           Product: gcc

           Version: 4.3.3

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: c++

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: dspe...@gmail.com





Created attachment 29079

  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29079

Preprocessed Source Code



The compiler said "internal compiler error: Segmentation fault. Please submit a

full bug report" so I am.  I realize there are few safe things to do with a

dereferenced null pointer, but usually sizeof is one of them.



Source code is attached.  I think the critical line is:



template<typename b> static void*

val(silliness<sizeof(static_cast<b*>(NULL)->s1)>*)



which was supposed to specialize if and only if b::s1 existed.  As you may have

guessed, this was an attempt to figure out why saner sfinae mechanisms weren't

working.



Here's the compiler output:



g++ -v --save-temps -o sfinae sfinae.cc

Using built-in specs.

Target: i486-linux-gnu

Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.3.3-5ubuntu4'

--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs

--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared

--with-system-zlib --libexecdir=/usr/lib --without-included-gettext

--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3

--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug

--enable-objc-gc --enable-mpfr --enable-targets=all --with-tune=generic

--enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu

--target=i486-linux-gnu

Thread model: posix

gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) 

COLLECT_GCC_OPTIONS='-v' '-save-temps' '-o' 'sfinae' '-shared-libgcc'

'-mtune=generic'

 /usr/lib/gcc/i486-linux-gnu/4.3.3/cc1plus -E -quiet -v -D_GNU_SOURCE sfinae.cc

-D_FORTIFY_SOURCE=2 -mtune=generic -fpch-preprocess -o sfinae.ii

ignoring nonexistent directory "/usr/local/include/i486-linux-gnu"

ignoring nonexistent directory

"/usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../i486-linux-gnu/include"

#include "..." search starts here:

#include <...> search starts here:

 /usr/include/c++/4.3

 /usr/include/c++/4.3/i486-linux-gnu

 /usr/include/c++/4.3/backward

 /usr/local/include

 /usr/lib/gcc/i486-linux-gnu/4.3.3/include

 /usr/lib/gcc/i486-linux-gnu/4.3.3/include-fixed

 /usr/include/i486-linux-gnu

 /usr/include

End of search list.

COLLECT_GCC_OPTIONS='-v' '-save-temps' '-o' 'sfinae' '-shared-libgcc'

'-mtune=generic'

 /usr/lib/gcc/i486-linux-gnu/4.3.3/cc1plus -fpreprocessed sfinae.ii -quiet

-dumpbase sfinae.cc -mtune=generic -auxbase sfinae -version -fstack-protector

-o sfinae.s

GNU C++ (Ubuntu 4.3.3-5ubuntu4) version 4.3.3 (i486-linux-gnu)

    compiled by GNU C version 4.3.3, GMP version 4.2.4, MPFR version 2.4.0.

GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072

Compiler executable checksum: e2b5a0303075a65d33d75f9466062812

sfinae.cc:28: internal compiler error: Segmentation fault

Please submit a full bug report,

with preprocessed source if appropriate.

See <file:///usr/share/doc/gcc-4.3/README.Bugs> for instructions.

Reply via email to