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

• Microsoft Fortran PowerStation for Windows 95 and Windows NT, version 4.0

SYMPTOMS

An illegal use of a dummy variable specified by the INTENT(OUT) statement does not cause an appropriate compile-time error or warning message to be generated.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

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