[Bug fortran/83012] New: Simply contiguous pointer function not recognized as contiguous

[neil.n.carlson at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83012

            Bug ID: 83012
           Summary: Simply contiguous pointer function not recognized as
                    contiguous
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: neil.n.carlson at gmail dot com
  Target Milestone: ---

In the following example the pointer assignment "p => x%dataptr()" is rejected
because the compiler does not recognize the function result x%dataptr() as
contiguous when in fact it is simply contiguous by definition.  Note that there
is no error if the dummy variable x is declared as type(x) instead of class(x).

FWIW, the 6.4.1 compiler has no problems with this example.

module mod
  type :: foo
    integer, pointer, contiguous :: p(:)
  contains
    procedure :: dataptr
  end type
contains
  function dataptr(this) result(dp)
    class(foo), intent(in) :: this
    integer, pointer, contiguous :: dp(:)
    dp => this%p
  end function
end module

subroutine bar(x)
  use mod
  class(foo) :: x
  integer, pointer, contiguous :: p(:)
  p => x%dataptr()
end subroutine

The error message:

$ gfortran --version
GNU Fortran (GCC) 8.0.0 20171115 (experimental)

$ gfortran -c bug.f90 
bug.f90:19:7:

   p => x%dataptr()
       1
Error: Assignment to contiguous pointer from non-contiguous target at (1)