Is it possible to simultaneously debug VB6 and a C++ COM dll?

Question

I have a VB6 dll that is loaded by a VB6 frontend. This VB6 dll calls a C++ ATL dll via its COM interface. So, I can run from code in VB6 and I can debug in C++ also, however I can't seem to step through the VB6 code and then get into the C++ code. I feel that this should be possible. Currently I am doing the following steps

1. Start VB6 debugging
2. Start C++ debugging. This involves starting the VB6 front end and setting the working directory to the VB6 front end directory using the VS2008 Debugging Properties in the Options.
3. Execute the code and step through the VB6 code to the point where I should be entering the C++ code. I see the loaded symbols window changing in the VS2008 IDE.

Now, it looks like it should work, but I never hit any breakpoints in my C++ code. I hit the breakpoints if I don't start the VB6 debugging first.

Answer 1

You should be able to set vb6.exe as the startup program for your project in C++ and start debugging. Then in VB6, open the project and start debugging.

Answer 2

Make sure the PDB files for both projects are available for your debugger. If you see . Loaded '\filename', no matching symbolic information found in debug out, you need to add debug symbol search path in tools->optios->debug->symbols.