[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2009-10-16 20:35 -------
The first example,
   procedure(fun), pointer :: f
   f => my_dcos
   write(*,*) f(x)
looks fine to me. "fun" is elemental - and my_dcos is also elemental.

The second example is wrong: "fun" is elemental, but "my_dcos" is not thus
   f => my_dcos
is invalid per F2003, 7.4.2.2 Procedure pointer assignment:
 "If proc-pointer-object has an explicit interface, its characteristics shall
be
  the same as proc-target except that proc-target may be pure even if 
  proc-pointer-object is not pure and proc-target may be an elemental intrinsic
  procedure even if proc-pointer-object is not elemental."

The third example looks OK again - actually, it is the same as the first,
except that one uses an intrinsic elemental procedure (dcos).

Test case for the second example:

 module funcs
   implicit none
   integer, parameter :: dp = kind(1.0d0)
   abstract interface
      elemental function fun(x)
         import
         implicit none
         real(dp), intent(in) :: x
         real(dp) fun
      end function fun
   end interface
   contains
  function my_dcos(x)
    integer, parameter :: dp = kind(1.0d0)
    real(dp), intent(in) :: x
    real(dp) :: my_dcos
    my_dcos = cos(x)
  end function
end module funcs

program start
   use funcs
   implicit none
   procedure(fun), pointer :: f
   real(dp) x(3)
   x = [1,2,3]
   f => my_dcos
   write(*,*) f(x)
end program start


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Proc-pointer conformance    |Proc-pointer conformance
                   |checks                      |checks: Elemental-proc-ptr
                   |                            |=> non-elemental-proc


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41733