[Fortran-Experiments] Nested interface blocks with Bind(c)

[Tobias Burnus]

Hi,

the following valid code is rejected:
-------------------------------------
MODULE OpenGL_glut
IMPLICIT NONE

INTERFACE
  FUNCTION glutCreateMenu(func) BIND(C,NAME="glutCreateMenu")
    use iso_c_binding
    INTEGER :: glutCreateMenu
    INTERFACE
      SUBROUTINE func() BIND(C)
      END SUBROUTINE func
    END INTERFACE
  END FUNCTION glutCreateMenu
END INTERFACE
END MODULE OpenGL_glut
-------------------------------------

I think in order to make it fully work, one needs procedural pointers,
but at least the current error message could be improved:

test3.f90:9.31:
      SUBROUTINE func() BIND(C)
                              1
Error: Syntax error in BIND(C) statement at (1)

Maybe one could get this part also working without procedural pointers.
(I haven't thought about this in detail.)


Found when compiling f03gl, http://www-stone.ch.cam.ac.uk/pub/f03gl/.
Even with that part fixed, "C_FUNLOC" is missing.
Maybe given a better error message for C_FUNLOC than
   Error: Function 'c_funloc' at (1) has no IMPLICIT type
would be useful, too. (Ditto for C_F_PROCPOINTER().)

I don't know whether one can get C_FUNLOC working without procedural
pointers. (C_FUNLOC accepts either "a procedure that is interoperable,
or a procedure pointer associated with an interoperable procedure".
Maybe the first part is possible without the second?)

Using NAG f95 the examples work and are quite impressive.

Tobias