Q155160: FIX: Debugger Sees Only One Variable of Two with Same Name

Article: Q155160
Product(s): Microsoft C Compiler
Version(s): winnt:
Operating System(s): 
Keyword(s): kbCompiler kbVC500fix
Last Modified: 04-AUG-2001

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The information in this article applies to:

- The Integrated Debugger, included with:
   - *EDITOR Please do not choose this product*Microsoft Visual C++ 32-bit Edition* use 241, 265, 225, version 4.0 
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SYMPTOMS
========

If there are two global scope variables of the same name in a project, only one
symbol appears to exist when viewed in the debugger. The correct value is
displayed for one of the symbols. All other symbols with the same name are
displayed with that same value.

RESOLUTION
==========

The two resolutions are:

- Don't use the same name for variables of global scope in different files.

- Link with /pdb:none.

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
================

For example, in the sample code below, the debugger shows the same value for the
two variables, "i" in main.cpp and "i" in Func1.cpp. To watch the two variables
in the same Watch window, use the context operator. Add the following two
expressions in the Watch window:

     {,main.cpp,}i

     {,Func1.cpp,}i

Single-step through the code and notice that even though the two variables
actually contain different values at all times, they are always displayed with
the same value--the value of "i" in Main.cpp.

Sample Code
-----------

     // file main.cpp
     // Compile options needed: /Zi
     // main.cpp

     void Func1(int);

     int i=1;

     int main()
     {
         i = 200;

         Func1 (i);

         return 0;
     }
     // end of file main.cpp

     // file Func1.cpp
     // Compile options needed: none
     // Func1.cpp

     #include <stdio.h>

     float i=2.0f;

     void Func1(int n)
     {
         printf("\n n= %d",n);
         i = float(n+2);
         printf("\n hPf= %f", i);
     }

     // end of file Func1.cpp

Additional query words: kbVC420bug 10.20

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Keywords          : kbCompiler kbVC500fix 
Technology        : kbVCsearch kbAudDeveloper kbIntegratedDebugger
Version           : winnt:
Issue type        : kbbug
Solution Type     : kbfix

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