[Bug fortran/98915] New: OpenACC routine with a name directive does not compile

[Bug fortran/98915] New: OpenACC routine with a name directive does not compile

[kd486 at cam dot ac.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98915

            Bug ID: 98915
           Summary: OpenACC routine with a name directive does not compile
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kd486 at cam dot ac.uk
  Target Milestone: ---

Created attachment 50106
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50106&action=edit
Module file to reproduce issue

The OpenACC standard states that "The routine directive with a name may appear
in the specification part of a subroutine, function or module, and applies to
the named subroutine or function."

However, the following does not compile with Gfortran:

        function modifier(x) result(y)
            implicit none
            !$acc routine seq
            real(kind =8) :: x,y
            y = 2 * x
        end function modifier

        subroutine do_work
            implicit none
            !$acc routine(modifier) seq
            integer(kind = 4) :: i
            !$acc parallel loop collapse(3) independent private(i)
            do i = 1,q
            x(i,j,k) = 23.
            x(i,j,k) = modifier(x(i))
            end do
        end subroutine do_work

 gfortran -fopenacc -Wall -Wextra -c mymodule.f90
mymodule.f90:26:35:

   26 |             !$acc routine(modifier) seq
      |                                   1
Error: Invalid NAME ‘modifier’ in !$ACC ROUTINE ( NAME ) at (1)

[Bug fortran/98915] OpenACC routine with a name directive does not compile

[kd486 at cam dot ac.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98915

--- Comment #1 from Kiril Dichev <kd486 at cam dot ac.uk> ---
See attached file for reference, snippet in description is not quite correct as
I was trying to be brief

[Bug fortran/98915] OpenACC 'routine with a name' directive does not compile

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98915

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(Now: OpenACC spec issue #345)

I am not sure that a use as in attachment 50106 is really intended, namely:
placing the "acc routine" into a sibling procedure.

However, gfortran seems to reject too much – at least with the current wording.

The problem is that the diagnostic already happens at call time
(gfc_match_oacc_routine) which requires that the symbol has been encountered
before (during parsing) and the usage is such that it has to be in the current
scope and cannot be in the parent scope.