Re: Ada95 + FORTRAN 77

["Matthew Heaney" <matthew_heaney@acm.org>]

In article <7r07rr$gap$1@nnrp1.deja.com> , lafage8770@my-deja.com  wrote:

> procedure Adder (A : in Float; B: in Float; Sum : out Float);

You should be using the types in Interfaces.Fortran, and you should also
have a pragma Convention.


> pragma Import (Fortran, Adder, Link_Name => "adder_");
>
> A : Float := 12.0;
> B : Float := 13.0;
> Sum : Float;
> begin
> Adder (A, B, Sum);
> Put (A); Put (B); Put ('='); Put (Sum); New_Line;
>
> end Ftest;
> -------------------------------------------------------------------
> file adder.f:
>       SUBROUTINE ADDER (A, B, SUM)
>       REAL*4 A
>       REAL*4 B
>       REAL*4 SUM

The reason you need to use the scalar types declared in Interfaces.Fortran
is that you have no guarantee that REAL*4 is the same as an Ada Float type.


>       SUM = A + B
>       END
> file common_basic.ads:
> with Interfaces.Fortran; use Interfaces.Fortran;
>
> package Common_Basic is
>    type Basic_Common is record
>       X, Y, Z : Double_Precision;
>    end record;
>    Basic : Basic_Common;

You have the scalar types right, but you still need a pragma Convention for
your record type.  Otherwise, how do you know that the representation of the
record on the Ada side matches the rep on the Fortran side?


>    pragma Import(Fortran, Basic, Link_Name => "basic_");
> end Common_Basic;