I have a module where I define two types, where one extends the other. In this particular case, I first define a variable of the base-type and then convert it to the extended type. However, my current implementation results in an internal compiler error on gfortran GNU 10.3.0:
module my_test_module
type :: baseType
contains
procedure :: &
asExtended => baseType_asExtended
end type baseType
type, extends(baseType) :: extendedType
end type extendedType
contains
function baseType_asExtended(self) result(extended)
class(baseType), intent(in), target :: self
class(extendedType), pointer :: extended
select type(self)
class is (extendedType)
extended => self
class default
nullify(extended)
end select
end function baseType_asExtended
end module my_test_module
Program TEST
use my_test_module
implicit none
class(baseType), pointer :: &
generic_object
type(extendedType) :: &
extended_object
allocate(extendedType::generic_object) ! compiler error happens without this line as well
extended_object = generic_object%asExtended()
End Program TEST
error message:
34 | extended_object = generic_object%asExtended()
| 1
internal compiler error: in conv_function_val, at fortran/trans-expr.c:4158
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-10/README.Bugs> for instructions.
The same code has no problems compiling on intel’s ifort 2021.6.0 20220226.
Modifying the main program TEST as following stops the error from occurring on GNU:
Program TEST
use my_test_module
implicit none
class(baseType), pointer :: &
generic_object
type(extendedType) :: &
extended_object
type(extendedType), pointer :: &
generic_object_pointer
allocate(extendedType::generic_object)
generic_object_pointer => generic_object%asExtended()
extended_object = generic_object_pointer
End Program TEST
Why am I required to perform this extra step here on GNU? Is this something that could be addressed in the near future?