[OE-core] [PATCH 04/10] gtk.inc: add feature based on directfb

[Richard Purdie]

On Thu, 2011-12-08 at 17:12 +0000, Phil Blundell wrote:
> On Thu, 2011-12-08 at 16:55 +0000, Richard Purdie wrote:
> > The question is whether it makes sense to have directfb and X based gtk
> > in the same builds and package feeds or not. I can see that it might be
> > desired and that it likely is possible.
> 
> This is true, though there's nothing to stop a distro that particularly
> wants this from inventing their own stub recipes which just set
> PACKAGECONFIG appropriately and then require the generic version.  So
> it's really just a question of what we want to be the default in
> oe-core.
> 
> Also note that, although you can parallel install multiple versions of
> the gtk+ runtime on the target system, if you want the build system to
> be deterministic then (in the absence of per-recipe sysroot
> construction) you need some way to decide which one gets to provide the
> gtk+-2.0.pc that other recipes will build against.  (The different
> targets have different library sonames so you can't just swap them out
> at run time: a given binary will remain coupled to the particular Gtk
> variant that it was compiled against.)  And if the two variants could
> conceivably be different versions of GTK then you also need a way to
> deconflict ${includedir}/gtk-2.0.  
> 
> So it isn't quite as simple as just having the two recipes, there is a
> bit of extra policy involved as well.  And of course there would be all
> the normal overhead in terms of parse time, memory footprint and
> maintenance burden associated with having more recipes.  

This is the key detail I was missing. I thought they just might have
been a drop in replacement.

That isn't the case so this makes the choice easier, I think separate
recipes don't make sense based on this.

> So, in light of all the above plus the fact that everything is different
> with Gtk+3 anyway, my preference for supporting directfb on gtk+2 in
> oe-core would be to use PACKAGECONFIG and not have separate recipe
> files.

Agreed, given the above.

Cheers,

Richard