More C interopability: exporting overloaded procedures

[eos_pengwern]

How does one go about exporting overloaded, C-interoperable procedures from a DLL?

When programming in C, it's straightforward: just export each individual overloaded procedure. It's also straightforward when programming in Fortran for calling from the same Fortran program: use an interface block at the head of the module, viz:

[cpp]module gubbins

    interface foo
        module procedure sfoo, dfoo
    end interface

contains

    subroutine sfoo(x, bar)

        real(kind(1e0)), intent(in) :: x
        real(kind(1e0)), intent(out) :: bar
        .
        .
    end subroutine sfoo

    subroutine dfoo(x, bar)

        real(kind(1d0)), intent(in) :: x
        real(kind(1d0)), intent(out) :: bar
        .
        .
    end subroutine sfoo

end module gubbins[/cpp]

...and so on. But what if I want to export these functions to a DLL, which will be loaded from a program written in C? I'd like the header file to look like:

[cpp]void foo(float x, float bar);
void foo(double x, double bar);[/cpp]

... but how might I bring this about? At the moment I'm not quite sure where to start. Should the !DEC$ DELLEXPORT directives be placed in the procedures, in the interface block, or somewhere else? Is this even possible?

[Steven_L_Intel1]

The DLLEXPORT directives go in the procedures - always. Of course, C can't resolve the generic reference, so you'll have to call the specific procedure name from C.

[eos_pengwern]

Quoting - Steve Lionel (Intel)

The DLLEXPORT directives go in the procedures - always. Of course, C can't resolve the generic reference, so you'll have to call the specific procedure name from C.

Thanks Steve,

That's what I'd feared, but now I know,I can avoid wasting time trying to get around it!