ValueExtractor has some edge cases breaking IL2CPP builds

Environment

• Code source: Package manager
• Code version: “io.extendreality.zinnia.unity”: “1.16.0”
• Platform version: Unity 2019.2.21f1
• 3rd party dependencies: None

Steps to reproduce

• Create a new project,
• Add a script to the main scene that does the following

using UnityEngine;
using Zinnia.Data.Operation.Extraction;

public class Example : MonoBehaviour
{
    void Start()
    {
        // We force the type to appear
        Debug.Log(typeof(SurfaceDataCollisionPointExtractor));
    }
}

• Save the scene
• Set scripting backend to IL2CPP and build

Expected behavior

Should build.

Current behavior

IL2CPP compilation error.

It seems that ValueExtractor has some edge cases that breaks the AOT scripting restrictions causing the build to fail.

I tried setting Stripping level to high and it still won’t build.

Also, the class that I used to reproduce the error is SurfaceDataCollisionPointExtractor, but some other classes, like SurfaceDataCollisionDataExtractor don’t cause this problem, so it seems to be a problem with the type RaycastHit.

Part of the log which seems useful says:

error C2440: ‘type cast’: cannot convert from ‘int’ to RaycastHit_t19695F18F9265FE5425062BBA6A4D330480538C3’

[hawkwood]

I opened a case with Unity and just got the following response:

—-

It looks like there is invalid IL code in Zinnia.Runtime.dll. The problem happens in the Zinnia.Data.Operation.Extraction.ValueExtractor<TResultElement,TSourceElement,TEvent,TEventElement>.ClearSource method. In this case, TSourceElement is UnityEngine.RaycastHit. The C# code for ClearSource (from ILSpy) is:

[CompilerGenerated] public void ClearSource() { Source = (TSourceElement)null; }

Since UnityEngine.RaycastHit is a struct, it is not nullable, and therefore cannot be set to a value of null.

I don’t believe this is something we can correct on the Unity side.

[Bullrich]

I just tried with the new version and couldn’t replicate the issue anymore. Thank you very much for the fix!