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

[Vladimir Ivanov]

Vladimir, Paul, thanks for reviews!

> 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).

Good point. I'll take a look at it separately. Seems like 
MethodHandles.linkMethodHandleConstant() misses a special case for 
VarHandle invokers.

Best regards,
Vladimir Ivanov

>> 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;
>>                 }
>>             }
>