Re: Generating missing depfiles by an automake based makefile

[Tom Tromey]

Dmitry> i am not looking forward to -include (even though -include is
Dmitry> supported by bmake, gnu make and sun make).
Dmitry> -include robs the user the error message should make fails to rebuild a 
depfile.
Dmitry> i'd rather introduce rules to rebuild depfiles, as presented in the
Dmitry> earlier email.

It's been a long time since I worked on automake, but the dependency
tracking in automake is designed not to need to rebuild or pre-build dep
files.  Doing that means invoking the compiler twice, which is slow.
Instead, automake computes dependencies as a side effect of compilation.

What is the scenario where you both end up with an empty depfile and a
compilation that isn't out of date for some other reason?  That seems
like it shouldn't be possible.

Tom