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

• The integrated debugger included with: - Microsoft Visual C++, 32-bit Edition, version 4.2

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

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