[Bug fortran/59198] [4.7/4.8/4.9 Regression] ICE on cyclically dependent polymorphic types

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59198

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-11-20
                 CC|                            |janus at gcc dot gnu.org
            Summary|ICE on cyclically dependent |[4.7/4.8/4.9 Regression]
                   |polymorphic types           |ICE on cyclically dependent
                   |                            |polymorphic types
     Ever confirmed|0                           |1

--- Comment #1 from janus at gcc dot gnu.org ---
I tried to reduce this as far as I could, with the following result:


module decays

  implicit none

  type :: decay_term_t
     type(unstable_t), pointer :: unstable_product
  end type

  type :: decay_gen_t
     type(decay_term_t), allocatable :: term
     procedure(), nopass, pointer :: obs1_int
  end type

  type :: rng_t
  end type

  type, extends (decay_gen_t) :: decay_t
     class(rng_t), allocatable :: rng
  end type

  type :: unstable_t
     type(decay_t) :: decay
  end type

  class(decay_t), pointer :: object

end


The ICE I get with trunk is:

c0.f90:18:0: internal compiler error: in tree_low_cst, at tree.h:3667
      class(rng_t), allocatable :: rng
 ^
0xb0735b tree_low_cst
    /home/jweil/gcc49/trunk/gcc/tree.h:3667
0xb0735b output_constructor_array_range
    /home/jweil/gcc49/trunk/gcc/varasm.c:4836
0xb0735b output_constructor
    /home/jweil/gcc49/trunk/gcc/varasm.c:5210
0xb066fa assemble_variable(tree_node*, int, int, int)
    /home/jweil/gcc49/trunk/gcc/varasm.c:2125
0xb081f5 varpool_assemble_decl(varpool_node*)
    /home/jweil/gcc49/trunk/gcc/varpool.c:454
0x6cff87 output_in_order
    /home/jweil/gcc49/trunk/gcc/cgraphunit.c:1955
0x6cff87 compile()
    /home/jweil/gcc49/trunk/gcc/cgraphunit.c:2194
0x6d01f9 finalize_compilation_unit()
    /home/jweil/gcc49/trunk/gcc/cgraphunit.c:2276
0x831204 write_global_declarations()
    /home/jweil/gcc49/trunk/gcc/langhooks.c:323


Similar things happen 4.8 and 4.7. However, I can not reproduce the ICE with
4.6.4:

$ gfortran-4.6 -v
Using built-in specs.
COLLECT_GCC=gfortran-4.6
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.6.4-3ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --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-gnu-unique-object --enable-plugin
--enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.4 (Ubuntu/Linaro 4.6.4-3ubuntu1)