Article: Q150003
Product(s): Microsoft C Compiler
Version(s): winnt:
Operating System(s):
Keyword(s): kbDebug kbide kbVC500fix
Last Modified: 31-JUL-2001
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The information in this article applies to:
- The Integrated Debugger, used with:
- *EDITOR Please do not choose this product*Microsoft Visual C++ 32-bit Edition* use 241, 265, 225, versions 4.0, 4.1, 4.2
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SYMPTOMS
========
When you view the theApp variable in an AppWizard-generated MFC application, the
element values of __vfptr are not properly displayed in the debugger. For an
example, please see the "More Information" section of this article.
RESOLUTION
==========
Drag the address of __vfptr into the memory window, view the data in long-hex
format, and notice that the addresses to which the __vfptr variable points
appear.
STATUS
======
Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug was corrected in Visual C++ version 5.0.
MORE INFORMATION
================
Example
-------
1. Create a default AppWizard MFC application. In the InitInstance(), view the
theApp variable in the watch window.
2. Expand the theApp variable to view the following tree structure:
theApp
CWinApp
CWinThread
CCmdTarget
CObject
__vfptr = 0x00405118 // This is correct
Under Windows NT:
[0] CXX0030: Error: expression cannot be evaluated
[1] CXX0030: Error: expression cannot be evaluated
[2] CXX0030: Error: expression cannot be evaluated
[3] CXX0030: Error: expression cannot be evaluated
[4] CXX0030: Error: expression cannot be evaluated
Under Windows 95 (All values are incorrect):
[0] 0xf000e681
[1] 0xf000ff47
[2] 0xf000ff47
[3] 0xf000ff47
[4] 0xf000ff47
Additional query words: kbVC400bug
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Keywords : kbDebug kbide kbVC500fix
Technology : kbVCsearch kbAudDeveloper kbIntegratedDebugger
Version : winnt:
Issue type : kbbug
Solution Type : kbfix
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