PRB: Debugger Cannot Evaluate Out of Scope Named Constants

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

SYMPTOMS

The debugger's watch window cannot evaluate expressions that contain named constants that have gone out of scope. Attempting to use a variable evaluation expression containing a locally undefined named constant in one of the watch windows causes the message "EE2347: Undefined variable" to be returned in the corresponding value field.

STATUS

This behavior is by design.

MORE INFORMATION

The scope context operator allows you to view information about module variables that have gone out of scope. However, using the scope context operator in this manner does not apply to named constants. You cannot use the scope context operator to evaluate named constants.

Steps to Illustrate Behavior

1. Build the sample code provided in Developer Studio.



2. After successfully building the sample code, start a debugging session by selecting Debug from the Build menu and then choosing Step Into.



3. Step into the module subroutine MODULE_PROC. In a watch window, type:

   MY_MODULE::MODULE_PROC::Y

   The number 9.00000 is correctly displayed for the named constant Y.



4. Step into the internal module subroutine INTERNAL_PROC to the assignment statement of variable N. Note that the watch expression created in Step 3 is no longer valid because it references the named constant Y which is out of scope.



5. In the subroutine INTERNAL_PROC, evaluate the variables H and N and the named constant Y. In a watch window, do the following:
   
   To evaluate H using the scope context operator, type:

   {MY_MODULE::MODULE_PROC::INTERNAL_PROC}H

   To evaluate N using the scope context operator, type:

   {MY_MODULE::MODULE_PROC::INTERNAL_PROC}N

   Evaluation of Y will fail when out of scope or when using the scope context operator.
   
   Using the scope context operator, type:

   {MY_MODULE::MODULE_PROC::INTERNAL_PROC}Y

   -or-
   
   Without the scope context operator, type:

   MY_MODULE::MODULE_PROC::INTERNAL_PROC::Y

Sample Code

! Compile options needed: /Zi
      MODULE MY_MODULE
        INTEGER H
      CONTAINS
        SUBROUTINE MODULE_PROC
          PARAMETER(Y=9.0)
          CALL INTERNAL_PROC
        CONTAINS
            SUBROUTINE INTERNAL_PROC
              INTEGER N
              N = Y + H
            END SUBROUTINE INTERNAL_PROC
        END SUBROUTINE MODULE_PROC
      END MODULE MY_MODULE

      PROGRAM TEST
        USE MY_MODULE
        CALL MODULE_PROC
      END PROGRAM TEST 

Additional query words: 4.00

Keywords : kbFortranPS kbLangFortran
Version : :4.0
Platform : NT WINDOWS
Issue type :