Samba4 dependencies?

[tridge at samba.org]

Volker,

 > If I change something in torture/rpc/samba3rpc.c (no
 > prototypes changed) and do a make, then all of torture/rpc
 > and torture/libnet is recompiled.
 > 
 > Is that necessary?

That was caused by svn 17754. Metze removed the code in mkproto.pl
which avoided the creation of a new proto header if it hadn't
changed. The reason metze changed this is that after a few weeks of
coding make was starting to call mkproto.pl on every prototype header
on every compile. This happened because make had no way of knowing
that the prototype didn't need updating.

I don't think either solution is really good. If we use the "smart"
mode like we used to in mkproto.pl then make eventually gets slow. If
we use the "dumb" mode like we currently have in the tree then we
recompile stuff far too often.

We need to find a 3rd solution, or we need to go back to doing "make
proto" manually. It's just too painful doing development with either
of the above.

How about this:

 - revert 17754
 - add a target "make proto" forces --always-create and recreates all
   proto headers

Then add something to the developer docs saying that when make gets
really slow, run "make proto". That way we will only do unnecessary
rebuilds occasionally.

Metze, Jelmer, you ok with that?

Cheers, Tridge