On Thu, Mar 21, 2019 at 09:04:21PM +0100, Thomas Schwinge wrote:
> Hi!
>
> On Wed, 20 Mar 2019 11:07:31 +0100, I wrote:
> > On Fri, 26 Aug 2016 08:16:43 -0700, Cesar Philippidis
> > <ce...@codesourcery.com> wrote:
> > > While working on [...], I noticed
> >
> > If only all such issues would end up in their own PRs, instead of mixing
> > them with other changes...
> >
> > > that the fortran FE wasn't permitting
> > > named functions inside acc routine directives. E.g.
> > >
> > > integer :: foo
> > > !$acc routine(foo) gang
> > >
> > > ... = foo ()
> >
> > ACK. Perhaps not the most pretty style, but gfortran does accept this.
> >
> > Do I understand right that there exists no equivalent syntax in Fortran
> > to declare a subroutine (instead of a function) with implicit EXTERNAL
> > attribute? (See also the new 'gfortran.dg/goacc/pr89773.f90' test case
> > I'm adding.)
>
> (Still interested if there's a way to do that.)
>
You're question make so sense to me as it seems you're
conflating IMPLICIT type with implicit interface. The
F2018 standard has
15.4.2.1 Interfaces and scopes
The interface of a procedure is either explicit or implicit.
It is explicit if it is
. an internal procedure, module procedure, or intrinsic procedure,
· a subroutine, or a function with a separate result name, within
the scoping unit that defines it, or
· a procedure declared by a procedure declaration statement that
specifies an explicit interface, or by an interface body.
Otherwise, the interface of the identifier is implicit. The interface
of a statement function is always implicit.
These two program are equivalent
program foo
external bar
external bah
call bar(a,i)
x = bah()
end program
program foo
call bar(a,i)
x = bah()
end program
except the former explicitly tells the compiler that bar and bah
are external. The "return type" with respect to C of bar is always
void. All subroutines with either an explicit or implicit interface
have a void "return type". The return type for bah() is *implicitly*
determined by the 'b' in the function function name. In this case,
bar() has an implcit type of REAL.
--
Steve
