BUG: Derived-Type with Pointer Expands Incorrectly in Debugger

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

SYMPTOMS

When you debug a derived-type variable that contains a pointer to another derived-type object and you try to view the members of the pointed to object in a watch window, it fails. This causes the pointer to member structure to be incorrectly expanded out.

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

Steps to Reproduce Problem

Build the following sample code in Developer Studio with the /Zi compiler option, and then perform the following steps:

1. Begin a debugging session; On the Developer Studio Debug menu, click Build, and then click Step Into.

2. Step through the main program beyond the allocate statement.

3. In a watch window, type the variable name "root," and press the ENTER key.

4. View the members of root. Click each of the (+) nesting symbols to expand each level of the derived-type object root.

   Invalid structure member

Sample Code

C Compile options needed: /Zi

      module types
        type t_leaf
          integer i
        end type t_leaf

        type t_branch
          type (t_leaf), pointer :: l
        end type

        type t_root
          type (t_branch) b
        end type
      end module types

      program main
        use types
        implicit none

        type (t_root) root
        allocate( root%b%l )

        root%b%l%i = 5
      end program main