Xcode not fully indexing engine files

I’m new to UE and can’t understand why it exactly happens but when i’m using xcode as code editor it’s not highlighting code at all, and furthermore, it’s not even finds “EngineMinimal.h”. Seems to me that xcode does not indexing a bunch of files because indexing process completes to fast. I’m using xcode 8.2.1 and UE 4.14.3.