[10] RFR (XS): 8194963: SystemDictionary::link_method_handle_constant() can't link MethodHandle.invoke()/invokeExact()

[Paul Sandoz]

Hi,

Fix looks ok.

VarHandle sigpoly methods also leverage an appendix argument, see the upcall to MethodHandleNatives.linkMethod. Might they be affected too?

However, i believe there might be a limitation in HotSpot such that it’s not possible to resolve method references to VarHandle sigpoly methods (something that was likely missed with the VarHandle integration).

Thanks,
Paul.

> On 12 Jan 2018, at 07:39, Vladimir Ivanov <vladimir.x.ivanov at oracle.com> wrote:
> 
> http://cr.openjdk.java.net/~vlivanov/8194963/webrev.00/
> https://bugs.openjdk.java.net/browse/JDK-8194963
> 
> It's a fix for a bug introduced by 8188145 [1].
> 
> MethodHandle.invoke()/invokeExact() have an implicit appendix argument (MethodType isntance) which is used for type checking method handle against call site.
> 
> MemberName resolution doesn't support such methods (with appendix argument), because there's no way to attach an appendix to MemberName.
> 
> Before 8188145, it was handled in JDK code [2], but now JVM performs MemberName resolution first before doing the upcall into JDK.
> 
> The fix is to avoid resolving those methods in SystemDictionary::link_method_handle_constant() (they are well-known, public, signature polymorphic) and only resolve method descriptor before doing the upcall.
> 
> Testing:
>  * failing tests, jdk/java/lang/invoke
>  * hs-precheckin-comp, hs-tier1, hs-tier2, jdk-tier1, jdk-tier2 (in progress)
> 
> Thanks!
> 
> Best regards,
> Vladimir Ivanov
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8188145
> 
> [2] http://hg.openjdk.java.net/jdk/hs/file/bade224cc81e/src/java.base/share/classes/java/lang/invoke/MethodHandles.java#l2446
>        MethodHandle linkMethodHandleConstant(byte refKind, Class<?> defc, String name, Object type) throws ReflectiveOperationException {
> ...
>            // Treat MethodHandle.invoke and invokeExact specially.
>            if (defc == MethodHandle.class && refKind == REF_invokeVirtual) {
>                mh = findVirtualForMH(member.getName(), member.getMethodType());
>                if (mh != null) {
>                    return mh;
>                }
>            }