Re: ABSTRACT interfaces + PROCEDURE declarations

[Tobias Burnus <burnus at net-b dot de>]

Hi Janus,

Tobias Burnus wrote:
> [E-Mail regards PROCEDURE patch only]
>   
> implicit none
> procedure(REAL) :: proc
> end
>   
This is by the way the same as:
real proc
external proc

> implicit none
> procedure() :: proc
> end
>   
And this the same as:
external proc


An invalid program that is accepted:

module a
implicit none
interface z
  subroutine foo()
  end subroutine
  subroutine sub(a)
    integer :: a
  end subroutine sub
end interface
end module a

use a
implicit none
procedure(z) :: bar
end

z is a generic interface, but "C1212 (R1215) The name shall be the name
of an abstract interface or of a procedure that has an explicit interface."



Intrinsic procedure make also trouble:

(I am not sure whether these have to be handled correctly from the
beginning, but they should either be fixed with one of the following
patches or there should be a PR for it.)



implicit none
procedure(cos) :: bar
end

gives the error:
  Error: Symbol 'cos' at (1) has no IMPLICIT type

The following compiles but is invalid:

implicit none
intrinsic cos
procedure(cos) :: bar
call bar()
end

NAG f95 diagnoses:
Error: a.f90, line 4: Too few arguments in reference to BAR


The following is valid but rejected:

implicit none
intrinsic cos
procedure(cos) :: bar
print *, bar(4.4)
end

Error: Function 'bar' at (1) has no IMPLICIT type


And the following is invalid but accepted:

implicit none
intrinsic amax1
procedure(amax1) :: bar
end

NAG diagnoses:
Error: b.f90, line 3: AMAX1 is not the name of a specific intrinsic that
may be used a proc-interface
(MAX is marked with a bullet in the 13.6; cf. C1212.)
Cf.  intrinsic.c and  ACTUAL_NO/ACTUAL_YES.

(MAX itself would be additionally invalid as it is no specific name to
an intrinsic function as NAG f95 also diagnoses:
Error: b.f90, line 3: MAX is not a specific intrinsic function name
Error: b.f90, line 3: MAX is not the name of a specific intrinsic that
may be used a proc-interface)


For:

implicit none
intrinsic cos
procedure(cos) :: sin
 print *, sin(3.3)
end

I would expect that this give a link error for "sin_", but it is
accepted. The analogous:
  interface
    function sin(x)
      real :: sin, x
    end function
  end interface
  print *, sin(3.3)
gives this error.

Note: "procedure(cos)" means the interface of the specific interface of
COS, i.e. only real arguments are allowed; for double precision "dcos"
has to be used.

Tobias