Where to find Documentation for Build Configuration

Hi,

I can find build configuration reference at URL: https://help.apple.com/xcode/mac/10.0/#/itcaec37c2a6

But If I consider configutaion key for example WARNING_CFLAGS, where I can find possible flag values that can be set and it's details for same flag ?

I am looking for some similar man pages for specific configuration.

Thanks in advance.