[foreign] RFC: unify function and layout

[Sundararajan Athijegannathan]

+1

But Descriptor.java is missing copyright.

-Sundar

On 23/11/18, 11:51 PM, Maurizio Cimadamore wrote:
> Hi,
> I've put together a patch which unifies both Layout and Function under 
> a common root type, called Descriptor:
>
> http://cr.openjdk.java.net/~mcimadamore/panama/layout%2bfunc_v2/
>
> The reason why I explored this direction is that there are few points 
> where we need some commonality between layouts and functions; for 
> instance, we have already discussed how function descriptors will need 
> to support some form of annotation (in the style of layout 
> annotations); this is needed both by the new annotation format under 
> discussion in [1] but also if we are to give 'names' to callbacks, so 
> that we can refer to function descriptors 'by name' (this is useful in 
> cases like qsort).
>
> Another pain point is that the Address layout currently pays the 
> biggest price for the lack of such common abstraction: a pointer can 
> either point to a memory location (object in C lingo) or to a 
> function. If we unify these two, then all Address layouts point to an 
> (optional, because of void) descriptor, and the API can be simplified 
> (a lot, in fact).
>
> There's also some hiccups around parsing declaration in @NativeHeader, 
> although this is transitory and will go away if we switch to a 
> different annotation scheme.
>
> Overall, after playing with it, I believe this patch significantly 
> improves the API, w/o adding significant complexity/surface area.
>
> Comments?
>
> Cheers
> Maurizio
>
> [1] - 
> http://mail.openjdk.java.net/pipermail/panama-dev/2018-November/003220.html
>
>
>