Invalid interface method implementations

[thegu5]

This was already mentioned in #cpp2il-support, I'm making this issue for organization.

example:


The method in the interface is public, but the method in the implementing class is private, causing the type to be invalid

Method 'OnBeforeSerialize' in type 'UnityEngine.Events.UnityEvent`1' from assembly 'UnityEngine.CoreModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' does not have an implementation.

(this specific example's error is because UnityEvent`1 extends UnityEventBase which implements ISerializationCallbackReceiver, and it doesn't see the method impl in UnityEventBase)

https://github.com/Unity-Technologies/UnityCsReference/blob/c4a2a4d90d91496bf3d4602778223a0e660c2a56/Runtime/Export/UnityEvent/UnityEvent.cs#L743

[ds5678]

From my perspective, everything is fine, except for your decompiler. That's an explicit interface implementation, so it's supposed to be private. It's just not supposed to show an access modifier in the source code.

https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/interfaces/explicit-interface-implementation

[SamboyCoding]

I'm guessing one possibility is that the explicit implementation info is not being set (it's a separate field to specify it should inherit from the interface) and so ILSpy is decompiling it wrong. That or one of the combinations of flags (private final hidebysig specialname newslot virtual) is missing.

[thegu5]

explicit implementation info is not being set

Looked at it again, this seems to be the case (?)

Correct example (sharplab):

    .method private final hidebysig newslot virtual 
        instance void A.Method () cil managed 
    {
        .override method instance void A::Method()
        .maxstack 8

        IL_0000: ret
    }

Cpp2IL output, missing .override:

	.method private final hidebysig newslot virtual 
		instance void UnityEngine.ISerializationCallbackReceiver.OnBeforeSerialize () cil managed 
	{
		.maxstack 8

		IL_0000: ldnull
		IL_0001: throw
	}

[SamboyCoding]

Yup ok, this is an old issue that's resurfaced then.