Not rebuilding dependencies

[Jason Elbaum]

Is it possible to define a make rule such that the target will be
(re)built if the dependency has changed, but no attempt will be made to
rebuild the dependency? That is, in:

a: b

If b has been changed, a will be rebuilt from it. If b has not been
changed (or doesn't exist), no action will be taken even if b's
dependencies have changed.


Can this only be done by putting this rule in a separate makefile?


Thanks,


Jason Elbaum
address@hidden