https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61376
Bug ID: 61376
Summary: Error using private statement in polymorphic derived
type
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: stuart.moffatt at axsym dot co.uk
I am getting a compiler error with the gfortran v4.9.0 compiler when using the
private statement within a derived type class that is used to form a
polymorphic object. Conversely, ifort v14.0.2 does compile this code
successfully and the executable runs without error. The example source code
below results in the following error message from gfortran:
*** START ERROR MESSAGE ***
ch2605.poly.f90:58.2:
s %x = shape_type(3)
1
Error: Assignment to an allocatable polymorphic variable at (1) is not yet
supported
*** END ERROR MESSAGE ***
If the private statement is commented out and the entire shape_module
attributes/methods are made public, then gfortran compiles the code
successfully. It appears that there is no straightforwward way to make the
contents of the base derived type private.
Notes: I have adapted this example source code from ch2605_2.f90 on the
fortranplus website. Standard gcc-4.9 installation using apt-get on Ubuntu
14.04 LTS. gfortran compiler options: -fcoarray=single.
*** START EXAMPLE SOURCE CODE ***
! Test to demonstrate problem private attributesin polymorphic
! derived type using gfortan v4.9.0 (works OK in ifort v14.0.2)
module shape_module
implicit none
private ! *** Commenting out this statement works with gfortran v4.9.0
type shape_type
integer :: n_
character(len=2), allocatable, dimension(:) :: cname_
contains
procedure, pass(this) :: get_size
end type shape_type
interface shape_type
module procedure shape_type_constructor
end interface
interface assignment (=)
module procedure generic_shape_assign
end interface
public :: shape_type, generic_shape_assign
public :: shape_type_constructor, get_size ! *** Not even this works.
contains
type (shape_type) function shape_type_constructor(n)
implicit none
integer, intent (in) :: n
shape_type_constructor%n_ = n
allocate ( shape_type_constructor%cname_(n) )
end function shape_type_constructor
integer function get_size(this)
implicit none
class (shape_type), intent (in) :: this
get_size = size(this%cname_)
end function get_size
subroutine generic_shape_assign(lhs,rhs)
implicit none
class (shape_type), intent (out), allocatable :: lhs
class (shape_type), intent (in) :: rhs
allocate (lhs,source=rhs)
end subroutine generic_shape_assign
end module shape_module
module shape_wrapper_module
use shape_module
type shape_wrapper
class (shape_type), allocatable :: x
end type shape_wrapper
end module shape_wrapper_module
program ch2605_mod
use shape_module
use shape_wrapper_module
implicit none
type (shape_wrapper) :: s
s %x = shape_type(3)
print *, 'size = ', s%x%get_size()
end program ch2605_mod
*** END EXAMPLE SOURCE CODE ***
