[Bug fortran/94137] New: [OpenACC] declare directive – currently *only* permitted after variable declaration

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94137

            Bug ID: 94137
           Summary: [OpenACC] declare directive – currently *only*
                    permitted after variable declaration
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Keywords: openacc, rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
  Target Milestone: ---

The spec has:
  "A declare directive is used in the declaration section of a Fortran
  subroutine, function, or module, or following a variable declaration
  in C or C++."

Hence, the an arbitrary order is permitted in Fortran (but not in C/C++).
However, gfortran rejects the following as "A" is not known:

  !$acc declare copy(A)
  integer :: A
  dimension :: A(20)
  end

gfortran currently requires that the identifier (gfc_symbol) is known when
parsing the directive.

Additionally, some checks are already performed on the symbol during parsing. I
think those are fine and the critical checks are only performed during
resolution, but I might be wrong.