MethodHandles.constant not inlining?

[Charles Oliver Nutter]

On Wed, Jun 8, 2011 at 12:22 AM, John Rose <john.r.rose at oracle.com> wrote:
> What is the type you pass to MHs.constant?  If it's not Object, call it T.

The more direct answer: it's T...in my case, the actual type of the
object given. I expected that to be better than making it Object and
wrapping it in an explicitCast or something...

>
> In the case of a type other than Object, we have:
>  rawRetype(#wellKnownIdentityFn, methodType(T, T)).bindTo(foo)
>
> where rawRetype is an internal trusted constructor which asserts that the result is trusted to be T, not just Object.  This should inline also.  There's a potential problem here:  The methodHandleWalk module will emit a return of an Object value (from wellKnownIdentityFn, not its real name) from an adapter that returns a value of type T.  This bytecode would be rejected by the verifier, but I don't think the verifier runs on MH graphs.
>
> Maybe the methodHandleWalk modules is tripping over some aspect of this MH graph or the resulting bytecode.

I will be very interested to see what comes out of this :)

- Charlie