[jdk17] RFR: 8267421: j.l.constant.DirectMethodHandleDesc.Kind.valueOf(int) implementation doesn't conform to the spec regarding REF_invokeInterface handling

[Vicente Romero]

On Fri, 11 Jun 2021 15:15:12 GMT, Vicente Romero <vromero at openjdk.org> wrote:

>> This PR is a copy of [PR-4416](https://github.com/openjdk/jdk/pull/4416) which was intended to openjdk/jdk.
>> 
>> Please review this PR which is syncing the implementation of `DirectMethodHandleDesc.Kind.valueOf(int)` and `DirectMethodHandleDesc.Kind.valueOf(int, boolean)` with its spec. My reading of the method's spec is that if the value of the refKind parameter is: MethodHandleInfo.REF_invokeInterface, then DirectMethodHandleDesc.Kind.valueOf(int, boolean) should be called with a value of true for its second argument, currently it is invoked with false regardless of the value of the refKind parameter
>> 
>> TIA
>
> src/java.base/share/classes/java/lang/constant/DirectMethodHandleDesc.java line 143:
> 
>> 141:                 }
>> 142:                 if (kind.refKind == refKind &&
>> 143:                         (refKind != REF_invokeStatic || refKind != REF_invokeSpecial || kind.isInterface == isInterface)){
> 
> @mlchung 13 hours ago Member
> 
> It reads to me that the static initializer tries to set up the table such that valueOf(refKind, isInterface) should find the proper kind to return except this:
> 
> // There is not a specific Kind for interfaces
> if (kind == VIRTUAL) kind = INTERFACE_VIRTUAL;
> 
> This changes the entry for REF_invokeVirtual to kind INTERFACE_VIRTUAL. Do you know why? If this entry is set to VIRTUAL, then each refKind has two entries in the table corresponding to the correct result for valueOf.

this is the table that is being generated right now:

Table has 20 entries
0: null
1: null
2: Kind: [name: GETTER, refKind: 1, isInterface: false]
3: Kind: [name: GETTER, refKind: 1, isInterface: false]
4: Kind: [name: STATIC_GETTER, refKind: 2, isInterface: false]
5: Kind: [name: STATIC_GETTER, refKind: 2, isInterface: false]
6: Kind: [name: SETTER, refKind: 3, isInterface: false]
7: Kind: [name: SETTER, refKind: 3, isInterface: false]
8: Kind: [name: STATIC_SETTER, refKind: 4, isInterface: false]
9: Kind: [name: STATIC_SETTER, refKind: 4, isInterface: false]
10: Kind: [name: VIRTUAL, refKind: 5, isInterface: false]
11: Kind: [name: INTERFACE_VIRTUAL, refKind: 9, isInterface: true]
12: Kind: [name: STATIC, refKind: 6, isInterface: false]
13: Kind: [name: INTERFACE_STATIC, refKind: 6, isInterface: true]
14: Kind: [name: SPECIAL, refKind: 7, isInterface: false]
15: Kind: [name: INTERFACE_SPECIAL, refKind: 7, isInterface: true]
16: Kind: [name: CONSTRUCTOR, refKind: 8, isInterface: false]
17: Kind: [name: CONSTRUCTOR, refKind: 8, isInterface: false]
18: Kind: [name: INTERFACE_VIRTUAL, refKind: 9, isInterface: true]
19: Kind: [name: INTERFACE_VIRTUAL, refKind: 9, isInterface: true]

-------------

PR: https://git.openjdk.java.net/jdk17/pull/29