VisualStudio Code Map cannot visualize Unreal source code

I use the trial version of VisualStudio 2015 Enterprise edition, wanna use CodeMap to help understand the unreal source code. I have successfully build the entire solution, but seems CodeMap don’t understand the UE4 project. I have test the CodeMap, it can visualize the normal DX11 C++ project, see the image below.
Anyone knows?

CodeMap OfficialDoc:
https://msdn.microsoft.com/en-us/library/dd409453.aspx

+1, same issues on these, tried compile project with unreal engine source, the code map for engine part works well but still not work for my own code.