[PATCH] libdrm: Convert to Android.mk to Android.bp

[John Stultz]

On Wed, Sep 25, 2019 at 3:39 AM Eric Engestrom <eric.engestrom at intel.com> wrote:
>
> On Tuesday, 2019-09-24 23:09:08 -0700, John Stultz wrote:
> > On Tue, Sep 24, 2019 at 4:30 PM John Stultz <john.stultz at linaro.org> wrote:
> > > On Tue, Sep 24, 2019 at 3:24 PM Rob Herring <robh at kernel.org> wrote:
> > > > Trying to maintain something that works across more than 3 releases or
> > > > so is painful. I don't think android-x86 folks have the bandwidth to
> > > > maintain things older than that *and* update to newer versions. So I
> > > > think only supporting the n latest releases is good.
> > > >
> > > > Are .bp files for master/Q compatible back to N (or O)? IIRC, at least
> > > > for the first couple of releases with .bp files, they seemed to have
> > > > incompatible changes.
> > >
> > > I think there have possibly been some incompatible changes, as I know
> > > early w/ bp files things were more in flux. That said, there haven't
> > > been many changes to the libdrm bp files since the conversion was
> > > first done in 2017 (so Android O). I'll checkout N and validate so I
> > > can provide a more concrete assurance.
> >
> > Ah. Crud. You're right. The bp syntax has shifted enough over time to
> > cause problems w/ the current file when building against older Android
> > releases.   N falls over pretty hard, and O and even P have issues w/
> > "recovery_available: ", and "prebuilt_etc" syntax.  So my proposed
> > commit message mischaracterizes the state of older builds. Apologies!
> >
> > I'll try to reach out to the android devs to see if there's any sort
> > of compat magic that can be done to keep things working on older
> > versions. That said, I'm still torn, as without this the current
> > libdrm/master code is broken with AOSP/master and Q.  Its frustrating
> > we have to have this seemingly exclusive trade off.
> >
> > I'm curious if folks might be willing to consider something like an
> > upstream branch to preserve the build bits that work with prior
> > Android releases? Or any other ideas?
>
> Is _not_ deleting Android.mk an option?

Yea, the trouble is O and P will pick up the Android.bp files by
default, so you'd still see the issues or you'd run into duplicate
targets. I'm hoping I can still find some conditional magic tricks for
Android.bp.  I need to look at Mauro's patches though.

> That would have the obvious cost of duplicating the build system
> maintenance effort, but if that's the only way to not drop support for
> everything before Q...

Yea, I'm not eager to have two android build systems in the tree.
Having just one is duplicative enough.

> (fwiw, my ack only applies with "reasonable" support of previous
> versions :] )

Of course, I'm not planning on submitting this change further until I
can find something better.  Apologies again for my assumptions that it
would work with older bp implementations.  My only defence is, in
trying to validate w/ older releases yesterday, my build system pulled
down 135G of data and now my repo is somehow unshallowed and taking 4
times the amount of disk space it was using w/ just AOSP/master. :P So
validating across AOSP versions is no trivial thing.

thanks
-john