[Bug fortran/87336] New: [8/9 regression] wrong output for pointer dummy assiocated to target actual argument

[juergen.reuter at desy dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87336

            Bug ID: 87336
           Summary: [8/9 regression] wrong output for pointer dummy
                    assiocated to target actual argument
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: juergen.reuter at desy dot de
  Target Milestone: ---

The following code is expected to give:
 a [before] =  2 3 4
 arr =  2 3 4
 bounds =  2 4
 arr2=  200 200 200
 a [after]  =  200 200 200
(and did so with gfortran 5.4), but gives with gfortran 8 and 9:
 a [before] =            2           3           4
 arr =            2           2           2
 bounds =            2           4
 arr2=          200         200         200
 a [after]  =          200           3           4

The code is:

program main
  implicit none
  integer, target :: a( 2:4 )

  a = [2,3,4]
  print *, "a [before] = ", a
  call show( a )
  print *, "a [after]  = ", a

contains
  subroutine show( arr )
    integer, pointer, intent(in) :: arr(:)
    print *, "arr = ", arr
    print *, "bounds = ", lbound(arr), ubound(arr)
    arr(:) = 200
    print *, "arr2= ", arr
  end subroutine show
  end program

Discussed on c.l.f. Sep. 16, 2018.