Looking for Makefile advice if applicable

[Tom Yu]

Benjamin Kaduk <kaduk at mit.edu> writes:

> I think this is the sort of thing that the VPATH variable is for.
> So you could set VPATH = ../../builtin/des and declare dependencies
> on the bare des_int.h and des_keys.c names but pull in their
> contents from the original location.

autoconf-gnerated Makefiles rely on VPATH for building outside the
source tree, which will interfere with this usage.  Also, VPATH
functionality isn't very portable across Make implementations.  These
would make it harder for us to integrate upstream.  I'd have to think a
while about how best to do this without using VPATH.