[PATCH libdrm] meson: use pkg-config to detect libatomic_ops

[Eric Engestrom]

On Friday, 2018-03-09 15:48:51 +0000, Emil Velikov wrote:
> On 9 March 2018 at 11:47, Eric Engestrom <eric.engestrom at imgtec.com> wrote:
> 
> >> > +       dep_atomic_ops = []
> >> >
> >> The dummy dep_atomic_ops is needed for almost all cases in the if/else
> >> ladder. The exception being the .found() case.
> >
> > Actually, because of the way the `if` chain is written, the dep_atomic_ops
> > has to be created before the list; in the `if` cases before this one,
> > that dep might exist, but we don't need it. In the branch that uses it,
> > if we got in the branch then it exists, and we need it. In the branches
> > after that, it doesn't exist and we don't need it either.
> >
> > That means that only up to that branch can it contain anything;
> > afterwards, it's empty anyway.
> >
> > And like I said, it only has the effect of maybe on the branches before
> > adding unused flags to the compiler & linker, which shouldn't have any
> > effect anyway.
> >
> Let me see if I get this right:
> 
> You're saying that when dep_atomic_ops.found() == false, the
> dep_atomic_ops dependency listed in the respective will expand to
> no-op.
> I wasn't quite sure if that's the case, hence my pedantic suggestion ;-)

Exactly :)

> 
> Makes sense though, rb still stands.

OK, pushing in a minute

> 
> Thanks Eric!
> 
> -Emil