Re: HEADSUP: drm-current-kmod now installs sources

On Wed, 2019-08-14 at 13:59 -0600, Warner Losh wrote:
> On Wed, Aug 14, 2019 at 1:56 PM Ian Lepore <ian_at_freebsd.org> wrote:
> 
> > On Wed, 2019-08-14 at 12:00 -0700, John Baldwin wrote:
> > > On 8/14/19 11:06 AM, Kyle Evans wrote:
> > > > LOCAL_MODULES="" does seem like a sensible default when we're
> > > > not
> > > > building a native kernel.
> > > 
> > > Unfortunately kern.post.mk has no way of knowing that as
> > > MACHINE_*
> > > are already set to the TARGET_* values by the time this target is
> > > invoked.  Also, the 'make tinderbox' use case is a legit use case
> > > that some folks want (for CI, etc.)
> > > 
> > 
> > BUILDHOST_ARCH!= uname -p
> > .if ${BUILDHOST_ARCH} != ${TARGET_ARCH}
> > 
> > Unfortunately, I don't think it's as easy to compare the buildhost
> > running version with the version of source being built, unless the
> > build is started from the top level so that Makefile.inc1 sets the
> > variables.
> > 
> 
> We already know MACHINE_ARCH != TARGET_ARCH in Makefile.inc1 and
> already do
> different things based on it. But to be honest, I'd think there'd be
> times
> I'd absolutely want to build them all, and other times I wouldn't
> which
> strongly suggests some kind of knob specific for cross building the
> port/pkg-based kernel modules. We could then pass that knob into the
> kernel
> builds which would then not try to guess whether or not to build
> LOCAL_MODULES...
> 
> 

This is just about AUTOMATICALLY deciding to build something, based on
the presence of source code in an arbitrary fixed location outside of
the source tree on the build machine.  Anything set by the user should
be honored without question, including LOCAL_MODULES.  

My point is only that the build machinery should not be deciding to
build something the user didn't specify based on the existence of out-
of-tree files on the build machine (I'd like to put the period right
here in this sentence), unless there's a very high likelyhood that the
build being done is for the build machine.

Things like CI that want to include more than in-tree sources as part
of the build should be handling that by setting appropriate knobs as
part of invoking the build.

-- Ian