How can I clean up after a build?

I need to rebuild cgx. How can I clean up the previous build? There is no clean target in the Makefile. I am at the moment using brute force “rm -f *.o cgx” in the src directory. Is this the way to go?

You can write a clean rule in the makefile https://www.gnu.org/software/make/manual/html_node/Cleanup.html