Browsing cores > arduino with working Intellisense?

Is there a way of configuring PlatformIO for examining/browsing the entire:


folder with working Intellisense?

For example, if I wanted to examine the implementation of Serial I might create a megaatmega2560 project and define an object of type Serial and then use Go to Declaration to see the code.

But I’d like to examine all existing Arduino core code for certain target without having to write additional code myself.

By just opening the folder Intellisense, of course, can’t work because #defines, include paths, compiler flags etc. are not defined.