Re: How to exit an Ada program with (unix shell) error code?

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Martin wrote on comp.lang.ada:
> On May 14, 3:55 am, a...@anon.org (anon) wrote:
> [snip]
>
> > Also for Martin.
>
> > Can a user-created procedure (main subprogram) be concerned as a "public
> > parameterless library procedures.  No! The reason is that the procedure
> > is not public, it first must be bound by the binding process.
>
> > 10.2  (29) An implementation may restrict the kinds of subprograms it
> >            supports as main subprograms. However, an implementation is
> >            required to support all main subprograms that are public
> >            parameterless library procedures.
>
> Ohhh groan.....I think I see what you're trying to say but you've got
> the wrong end of the stick.
>
> It's saying that you can't have this as a main procedure:
>
> package Application is
> private
>    procedure Main;   -- NB: in private part of package-decl
> end Application;
>
>    or
>
> package Application is
>    ...
> end Application;
>
> package body Application is
>    ...
>    procedure Main;    -- NB: Declaration in body not spec
>    ...
>    procedure Main is
>    ...
>    end Main;
>    ...
> end Application;
>
> It's not taking about binding (as nothing in the RM talks about
> binding).

The following is not a "public library procedure" either since it is
not declared at library level:

package Application is -- package at library level
   procedure Main; -- subprogram not at library level
end Applicatin;

There is another non-portable, compiler-dependent possibility which is
to not have a main subprogram at all but instead to rely on
elaboration:

package Application is
   pragma Elaborate_Body;
end Application;

package body Application is
begin
   ...
end Application;

Again the RM does not require the compiler to support this, so this is
non-portable.

--
Ludovic Brenta.