Spin-off from PR 42144 (comment #6). As the following code demonstrates,
polymorphic type-bound operators are buggy:
module foo_module
implicit none
private
public :: foo
type :: foo
contains
procedure :: times => times_foo
procedure :: assign => assign_foo
generic :: operator(*) => times
generic :: assignment(=) => assign
end type
contains
function times_foo(this,factor) result(product)
class(foo) ,intent(in) :: this
class(foo) ,allocatable :: product
real, intent(in) :: factor
end function
subroutine assign_foo(lhs,rhs)
class(foo) ,intent(inout) :: lhs
class(foo) ,intent(in) :: rhs
end subroutine
end module
module bar_module
use foo_module ,only : foo
implicit none
private
public :: bar
type ,extends(foo) :: bar
private
real :: x=1.
contains
procedure :: times => times_bar
procedure :: assign => assign_bar
end type
contains
subroutine assign_bar(lhs,rhs)
class(bar) ,intent(inout) :: lhs
class(foo) ,intent(in) :: rhs
select type(rhs)
type is (bar)
lhs%x = rhs%x
end select
end subroutine
function times_bar(this,factor) result(product)
class(bar) ,intent(in) :: this
real, intent(in) :: factor
class(foo), allocatable :: product
select type(this)
type is (bar)
allocate(product,source=this)
select type(product)
type is(bar)
product%x = this%x*factor
end select
end select
end function
end module
program main
use foo_module ,only : foo
use bar_module ,only : bar
implicit none
type(bar) :: unit
call rescale(unit,3.141592654)
contains
subroutine rescale(this,scale)
class(foo) ,intent(inout) :: this
real, intent(in) :: scale
this = this*scale
end subroutine
end program
This test case is compiled flawlessly, but the generated code is wrong:
rescale (struct .class.foo & restrict this, real(kind=4) & restrict scale)
{
{
struct .class.foo.a D.1631;
D.1631 = times_foo ((struct .class.foo *) this, (real(kind=4) *) scale);
assign_foo ((struct .class.foo *) this, &D.1631);
}
}
The operators are always resolved to the base-class procedures. Polymorphic
treatment is missing.
--
Summary: [OOP] poylmorphic operators do not work
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: janus at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42385
