[11] RFR (S): 8203480: IncompatibleClassChangeError thrown at sites linked to default interface methods

[Vladimir Ivanov]

http://cr.openjdk.java.net/~vlivanov/8203480/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8203480

JDK-8072008 enabled MethodHandle linker elimination when MemberName is a 
compile-time constant, but target method isn't inlined. It involves 
method resolution step and attached method + linker are used to initiate it.

The problematic case is invokevirtual on a default method. As an example:

   interface I { default m() {} }
   class T implements I {}

   invokevirtual T.m() =R=> I.m()
   findVirtual(T.class, "m", ...) => DMH: MH.linkToVirtual(..., I.m())

During call site resolution, "invokevirtual I.m()" resolution is 
initiated and it fails link-time checks ending with an ICCE.

The fix is to adjust invocation mode for default methods from 
invokevirtual to invokeinterface: resolution succeeds for 
"invokeinterface I.m()" and it does the right thing.

Testing: hs-precheckin-comp, hs-tier1, hs-tier2 
(-XX:+-StressMethodHandleLinkerInlining)

Thanks!

Best regards,
Vladimir Ivanov