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Q148608: BUG: Derived-Type with Pointer Expands Incorrectly in Debugger

Article: Q148608
Product(s): Microsoft Fortran Compiler
Version(s): 4.0
Operating System(s): 
Keyword(s): kbFortranPS kbLangFortrankbbuglist
Last Modified: 03-NOV-1999

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The information in this article applies to:

- Microsoft Fortran PowerStation for Windows 95 and Windows NT, version 4.0 
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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" (without the quotation
  marks), 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.

Expanding root yields root%B%L%B%L%B%L instead of the correct pointer to member
structure of root%B%l%i. Typing in the correct pointer to member structure in a
watch window yields the following message in the corresponding value column:

  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

Additional query words: 4.00

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Keywords          : kbFortranPS kbLangFortran kbbuglist
Technology        : kbAudDeveloper kbPTProdChange kbFortranSearch kbFORTRANPower400NT
Version           : :4.0

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