[Java.Interop] remove DynamicallyAccessedMemberTypes.Interfaces

[jonathanpeppers]

Context: dotnet/android#9630

As #9630 required new declarations of
DynamicallyAccessedMemberTypes.Interfaces, we intestigated to see why these were needed in Java.Interop.

There are two cases:

var listIface   = typeof (IList<>);
var listType    =
    (from iface in type.GetInterfaces ().Concat (new[]{type})
        where (listIface).IsAssignableFrom (iface.IsGenericType ? iface.GetGenericTypeDefinition () : iface)
        select iface)
    .FirstOrDefault ();

This first one, if IList<> were trimmed away. We don't actually care, as everything in this code path would still work. We can suppress the warning instead.

The second case:

JniValueMarshalerAttribute? ifaceAttribute = null;
foreach (var iface in type.GetInterfaces ()) {
    marshalerAttr = iface.GetCustomAttribute<JniValueMarshalerAttribute> ();
    if (marshalerAttr != null) {
        if (ifaceAttribute != null)
            throw new NotSupportedException ($"There is more than one interface with custom marshaler for type {type}.");

        ifaceAttribute = marshalerAttr;
    }
}
if (ifaceAttribute != null)
    return (JniValueMarshaler) Activator.CreateInstance (ifaceAttribute.MarshalerType)!;

Feels like we should be able to remove this code completely.

With these changes we can remove DynamicallyAccessedMemberTypes.Interfaces.

I also introduced build-tools/trim-analyzers/trim-analyzers.props that will setup the appropriate trimmer MSBuild properties to make trimmer warnings an error. This should keep us from accidentally creating warnings. I only use this setting in projects that were already using $(EnableAotAnalyzer).

Copilot reviewed 5 out of 12 changed files in this pull request and generated no comments.

Files not reviewed (7)

• build-tools/trim-analyzers/trim-analyzers.props: Language not supported
• src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings.csproj: Language not supported
• src/Java.Interop/Java.Interop.csproj: Language not supported
• src/Java.Interop/Java.Interop/JniBuiltinMarshalers.cs: Evaluated as low risk
• src/Java.Interop/Java.Interop/JniRuntime.JniMarshalMemberBuilder.cs: Evaluated as low risk
• src/Java.Interop/Java.Interop/JniRuntime.JniValueManager.cs: Evaluated as low risk
• src/Java.Interop/Java.Interop/JniStringValueMarshaler.cs: Evaluated as low risk

Comments suppressed due to low confidence (2)

src/Java.Interop/Java.Interop/JniValueMarshaler.cs:123

• The removal of DynamicallyAccessedMemberTypes.Interfaces might cause issues if any code relies on dynamically accessed interfaces. Ensure that all necessary interfaces are still accessible and properly handled.

internal const DynamicallyAccessedMemberTypes Constructors = DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors;

src/Java.Interop/Java.Interop/JniValueMarshaler.cs:135

• Ensure that there are sufficient tests covering the behavior of CreateValue when only constructors are dynamically accessed. This is to ensure that no functionality relying on interfaces is broken.

public abstract object? CreateValue (ref JniObjectReference reference, JniObjectReferenceOptions options, [DynamicallyAccessedMembers (Constructors)] Type? targetType = null);

[jonathanpeppers]

/azp run

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[jonathanpeppers]

/azp run

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[jonathanpeppers]

@jonpryor I think the changes here + dotnet/android#9630 cause a crash in Mono.Android-Tests:

12-18 18:50:09.648  6790  6790 I DOTNET  : JavaProxyThrowable: obtaining Java stack trace threw an exception: System.NotImplementedException: Do not know how to dispose: Invalid.
12-18 18:50:09.648  6790  6790 I DOTNET  :    at Java.Interop.JniObjectReference.Dispose(JniObjectReference& reference)
12-18 18:50:09.648  6790  6790 I DOTNET  :    at Java.Interop.JniObjectReference.Dispose(JniObjectReference& reference, JniObjectReferenceOptions options)
12-18 18:50:09.648  6790  6790 I DOTNET  :    at Android.Runtime.AndroidValueManager.CreatePeer(JniObjectReference& reference, JniObjectReferenceOptions options, Type targetType)
12-18 18:50:09.650  6790  6790 I DOTNET  :    at Java.Interop.JavaPeerableValueMarshaler.CreateGenericValue(JniObjectReference& reference, JniObjectReferenceOptions options, Type targetType)
12-18 18:50:09.650  6790  6790 I DOTNET  :    at Java.Interop.JniRuntime.JniValueManager.GetValue(JniObjectReference& reference, JniObjectReferenceOptions options, Type targetType)
12-18 18:50:09.652  6790  6790 I DOTNET  :    at Java.Lang.Object.GetObject(IntPtr handle, JniHandleOwnership transfer, Type type)
12-18 18:50:09.652  6790  6790 I DOTNET  :    at Android.Runtime.JNIEnv.<CreateNativeArrayElementToManaged>g__GetObject|73_11(IntPtr e, Type t)
12-18 18:50:09.653  6790  6790 I DOTNET  :    at Android.Runtime.JNIEnv.<>c.<CreateNativeArrayElementToManaged>b__73_9(Type type, IntPtr source, Int32 index)
12-18 18:50:09.653  6790  6790 I DOTNET  :    at Android.Runtime.JNIEnv.CopyArray(IntPtr src, Array dest, Type elementType)
12-18 18:50:09.653  6790  6790 I DOTNET  :    at Android.Runtime.JNIEnv.<>c.<CreateNativeArrayToManaged>b__99_12(Type type, IntPtr source, Int32 len)
12-18 18:50:09.653  6790  6790 I DOTNET  :    at Android.Runtime.JNIEnv._GetArray(IntPtr array_ptr, Type element_type)
12-18 18:50:09.653  6790  6790 I DOTNET  :    at Android.Runtime.JNIEnv.GetArray(IntPtr array_ptr, JniHandleOwnership transfer, Type element_type)
12-18 18:50:09.653  6790  6790 I DOTNET  :    at Java.Lang.Throwable.GetStackTrace()
12-18 18:50:09.653  6790  6790 I DOTNET  :    at Android.Runtime.JavaProxyThrowable.TranslateStackTrace()

run-Mono.Android.NET_Tests-Debug-1285.binlog.zip

[jonpryor]

@jonathanpeppers wrote:

I think the changes here + dotnet/android#9630 cause a crash in Mono.Android-Tests

The cause of the crash is here:

JniObjectReference reference = new (handle);

The default type in the JniObjectReference constructor is .Invalid:

java-interop/src/Java.Interop/Java.Interop/JniObjectReference.cs

Line 77 in f800ea5

public JniObjectReference (IntPtr handle, JniObjectReferenceType type = JniObjectReferenceType.Invalid)

…which we don't know how to dispose, because we don't know what it is.

The fix is…another utility function!

partial class JNIEnv {
    internal static JniObjectReference CreateJniObjectReference (IntPtr handle, JniHandleOwnership transfer)
    {
        if (transfer.HasFlag (JniHandleOwnership.TransferLocalRef))
            return new JniObjectReference (handle, JniObjectReferenceType.Local);
        if (transfer.HasFlag (JniHandleOwnership.TransferGlobalRef))
            return new JniObjectReference (handle, JniObjectReferenceType.Global);
         return new JniObjectReference (handle); // there be possible dragons here!
    }
}

Then Object.GetObject<T>() is updated to use:

var reference = JNIEnv.CreateJniObjectReference (handle, transfer);