Right. Make already knows how to convert .c to .o, all you need to say is

    files.c: defs.h buffer.h command.h

and there are tools such as makedepend (for C and OCaml, off the top of my head) that generate those listings automatically, so you just add this to the Makefile:

    include (autogenerated dependency listing file)

While the mandatory tab in Make syntax is a genuine wart, make has been around long enough that there are several other tools that know how to work with it.

(Now, having the scan for access time changes added as a warning to Make might not be a bad idea. "WARNING: You forgot this dependency")