I want to disable builtin rules and variables as per passing the -r and -R options to GNU make, from inside the make file. Other solutions that allow me to do this implicitl
You could start the Makefile with a #! and call it something different so people don't try to use make directly:
#!/usr/bin/make -rRf
# ...
This will cause horrific problems if GNU make is not the system make. Maybe a wrapper script?
You can also read $(MAKEFLAGS) and make sure the required flags are present.