Another option would be to move from Makefiles to AAP, the build mechanism for vim. We did just that, and are very happy with it. Aap is python based, so the kind of question you have is very easily handled within the 'aap' file.
http://www.a-a-p.org/ Aap has the advantage that you don't need to define the dependencies yourself, it understands C files, and does the work for you. Our Makefile shrunk by a factor of 5 after converting to aap. Highly recommended. Bart van Deenen. -- http://mail.python.org/mailman/listinfo/python-list
