[Bug fortran/56731] New: [Fortran 4.7] ICE on (wrongly) referencing polymorphic array in select type

["tiloschwarz at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56731

             Bug #: 56731
           Summary: [Fortran 4.7] ICE on (wrongly) referencing polymorphic
                    array in select type
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: tiloschwarz@gcc.gnu.org
        Depends on: 56730


4.6 and current 4.8-branch and 4.9-trunk do not ICE.

% cat polymorph2.f08
program polymorph2

    type ta
        integer i
    end type ta

    type, extends(ta) :: tb
        integer j
    end type tb

    type ca
        class(ta), allocatable :: c
    end type ca

    type(tb), target :: b, c
    type(ca) carr(2)

    select type(an => carr%c)
        type is (tb)
            c = an
    end select

end program polymorph2

% gfortran-4.7 -v polymorph2.f08
Driving: gfortran-4.7 -v polymorph2.f08 -l gfortran -l m -shared-libgcc
Using built-in specs.
COLLECT_GCC=gfortran-4.7
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i486-linux-gnu/4.7/lto-wrapper
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.2-5'
--with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --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++/4.7
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --enable-targets=all --with-arch-32=i586
--with-tune=generic --enable-checking=release --build=i486-linux-gnu
--host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.7.2 (Debian 4.7.2-5) 
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=i586'
 /usr/lib/gcc/i486-linux-gnu/4.7/f951 polymorph2.f08 -quiet -dumpbase
polymorph2.f08 -mtune=generic -march=i586 -auxbase polymorph2 -version
-fintrinsic-modules-path /usr/lib/gcc/i486-linux-gnu/4.7/finclude -o
/tmp/ccznNIIm.s
GNU Fortran (Debian 4.7.2-5) version 4.7.2 (i486-linux-gnu)
        compiled by GNU C version 4.7.2, GMP version 5.0.5, MPFR version
3.1.0-p10, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU Fortran (Debian 4.7.2-5) version 4.7.2 (i486-linux-gnu)
        compiled by GNU C version 4.7.2, GMP version 5.0.5, MPFR version
3.1.0-p10, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
polymorph2.f08: In function 'polymorph2':
polymorph2.f08:1:0: internal compiler error: in gfc_conv_component_ref, at
fortran/trans-expr.c:1100
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.7/README.Bugs> for instructions.