[shakna]

I mentioned m4 before as a way of using more passes, and is how the Linux kernel approaches this, but looking deeper at make, I'm not even sure you need it.

From the manual, on implicit rules:

foo : foo.o bar.o cc -o foo foo.o bar.o $(CFLAGS) $(LDFLAGS)

Because you mention `foo.o' but do not give a rule for it, make will automatically look for an implicit rule that tells how to update it. This happens whether or not the file `foo.o' currently exists.

[erlehmann_]

I do not understand. I know that make(1) has many implicit rules – but which of the problems I mentioned does this solve and how? Please be specific about your solution.