Automatic dependency tracking

[Daniel Jacobowitz <drow at false dot org>]

On Mon, Jun 23, 2008 at 11:00:22AM -0600, Tom Tromey wrote:
> I can send out my unfinished Makefile.am for gdb if you really want
> it.  That would solve this problem.
> 
> "Unfinished" means it is like 30% done :-(
> 
> If we didn't mind requiring GNU make we could probably implement
> dependency tracking more simply.  I suspect that is still a no-go ...

Let's talk about this... I'd be very happy if we could remove the
manual dependency lists.

Option one: we could switch to automake.  That would bring dependency
tracking for free.  GDB already has a dependency on automake, so aside
from the work of the transition I don't think this would be a big
deal.  I'm not too fond of automake, but it does work.

Option two: we could require GNU make.  GCC has done this for years,
but binutils does not; it may be premature.

Option three: we could manually list dependencies on generated files,
and support dependencies on source files only on systems with GNU
make.  This effectively means GNU make is a requirement if you are
hacking on GDB, but not to build GDB from a clean tree.

Option four: We could borrow logic from BFD to generate dependency
lists.  What's going on with this code anyway?  Why does BFD need
dependency lists in Makefile.am if it uses automake?

Have I missed anything?  Any comments on these options?

-- 
Daniel Jacobowitz
CodeSourcery