RFR: 8187655: jdk.lambda.vm.InterfaceAccessFlagsTest.testPrivateMethodCall needs update after nestmates support

[Chen Liang]

On Mon, 6 Nov 2023 19:26:26 GMT, Mandy Chung <mchung at openjdk.org> wrote:

> `jdk.lambda.vm.InterfaceAccessFlagsTest` uses `ClassToInterfaceConverter` to mechanically convert a classfile for a Class into an in-memory class representation of an equivalent Interface.  `testPrivateMethodCall`  tests to invoke a private method. Before nestmates, invoking a private class method and a private interface method both use `Invokespecial`.   With the nestmate changes, the class uses `invokevirtual` but the interface must use `invokeinterface` but this conversion is not handled by the existing `ClassToInterfaceConverter`.
> 
> This fix converts `ClassToInterfaceConverter` to use the Class-File API to properly convert a classfile from a class to an interface including method invocation from `invokevirtual` to `invokeinterface`.  The old custom bytecode manipulation code can be dropped.

test/jdk/jdk/lambda/separate/ClassToInterfaceConverter.java line 39:

> 37: 
> 38:     private byte[] convertToInterface(ClassModel classModel) {
> 39:         return Classfile.of().build(classModel.thisClass().asSymbol(),

You can use `transform` to transform a class instead of `build`.

test/jdk/jdk/lambda/separate/ClassToInterfaceConverter.java line 43:

> 41:                     for (ClassElement ce : classModel) {
> 42:                         if (ce instanceof AccessFlags accessFlags) {
> 43:                             classBuilder.withFlags(0x0601); // ACC_INTERFACE | ACC_ABSTRACT | ACC_PUBLIC);

We can just use `withFlags(Classfile.ACC_INTERFACE | Classfile.ACC_ABSTRACT | Classfile.ACC_PUBLIC)` as it's a constant expression and inlined by javac. And the `accessFlags` variable above appears unused.

test/jdk/jdk/lambda/separate/ClassToInterfaceConverter.java line 52:

> 50:                             //  by other methods in the interface, convert it to InterfaceMethodref and
> 51:                             //  if opcode is invokevirtual, convert it to invokeinterface
> 52:                             classBuilder.withMethod(mm.methodName().stringValue(),

Same remark, use `classBuilder.transformMethod(mm, MethodTransform.transformCode((codeBuilder, e) -> {}))`

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PR Review Comment: https://git.openjdk.org/jdk/pull/16526#discussion_r1384280905
PR Review Comment: https://git.openjdk.org/jdk/pull/16526#discussion_r1384279751
PR Review Comment: https://git.openjdk.org/jdk/pull/16526#discussion_r1384284062