How to successful use VisualStudio CodeMap to visualize the UE4 source code?

It’s hard to understand the UE4 source code with reading thousand lines of code. I just find the VS CodeMap is a great tool to help learning the Unreal Architecture. But no lucky make it works with unreal solution. Is it because unreal has special source code organizational forms?(Assemling, Linking)

I have post a question at answerhub,
https://answers.unrealengine.com/questions/500838/visualstudio-code-map-cannot-visualize-unreal-sour.html

This is really a great tool to help learning, if anyone knows whats behind it, please help.