BUG: INTENT(OUT) Allows Subroutine to Use Undefined Argument

MORE INFORMATION

The INTENT(OUT) dummy argument must be defined by the subroutine before it is used. When the subroutine is started, the dummy argument is undefined, so any executable statement associated with it prior to its definition should cause a compilation error or warning.

Sample Code to Illustrate Problem

C Compile options needed: none

      real z
      z = 32
      call sub(z)
      print *, z
      end

      subroutine sub(x)
      real, intent(out) :: x
      print *, x   ! x undefined; No compiler warning or error generated
      X = 5
      end subroutine