Variables used in g++ compiler command line

I am trying to build some c++ code. The default command line for the c++ compiler has some include directories that I don’t want.
I think this would be easier if I know what variables were used to build the compiler command line but I can’t find that in the documentation anywhere. Is that documented somewhere?
I think I can modify the variable using set_target_properties, but I can’t figure out what properties are set on my target. Is there anyway to list what properties are set on a target?

I think you might want to configure with CMAKE_CXX_FLAGS=-nostdinc to remove those includes.