[release/9.0.1xx] introduce $(_AndroidIsAssignableFromCheck) escape hatch

build-tools/automation/azure-pipelines.yaml

@@ -215,6 +215,16 @@ extends:
             artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
             artifactFolder: $(DotNetTargetFramework)-AotLlvm
 
+        - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml@self
+          parameters:
+            configuration: $(XA.Build.Configuration)
+            testName: Mono.Android.NET_Tests-IsAssignableFrom
+            project: tests/Mono.Android-Tests/Runtime-Microsoft.Android.Sdk/Mono.Android.NET-Tests.csproj
+            testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)IsAssignableFrom.xml
+            extraBuildArgs: -p:TestsFlavor=IsAssignableFrom -p:IncludeCategories=Intune -p:_AndroidIsAssignableFromCheck=false
+            artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
+            artifactFolder: $(DotNetTargetFramework)-IsAssignableFrom
+
         - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml@self
           parameters:
             configuration: $(XA.Build.Configuration)

src/Mono.Android/Java.Interop/TypeManager.cs

@@ -39,6 +39,15 @@ public static Dictionary<Type, string> ManagedToJni {
 	}
 
 	public static partial class TypeManager {
+
+		const bool IsAssignableFromCheckEnabledByDefault = true;
+
+		const string FeatureSwitchPrefix = "Microsoft.Android.Runtime.RuntimeFeature.";
+
+		[FeatureSwitchDefinition ($"{FeatureSwitchPrefix}{nameof (IsAssignableFromCheck)}")]
+		internal static bool IsAssignableFromCheck { get; } =
+			AppContext.TryGetSwitch ($"{FeatureSwitchPrefix}{nameof (IsAssignableFromCheck)}", out bool isEnabled) ? isEnabled : IsAssignableFromCheckEnabledByDefault;
+
 		internal static string GetClassName (IntPtr class_ptr)
 		{
 			IntPtr ptr = RuntimeNativeMethods.monodroid_TypeManager_get_java_class_name (class_ptr);
@@ -336,7 +345,13 @@ internal static IJavaPeerable CreateInstance (IntPtr handle, JniHandleOwnership
 
 				handleClass = JniEnvironment.Types.GetObjectClass (new JniObjectReference (handle));
 				if (!JniEnvironment.Types.IsAssignableFrom (handleClass, typeClass)) {
-					return null;
+					if (Logger.LogAssembly) {
+						var message = $"Handle 0x{handle:x} is of type '{JNIEnv.GetClassNameFromInstance (handle)}' which is not assignable to '{typeSig.SimpleReference}'";
+						Logger.Log (LogLevel.Debug, "monodroid-assembly", message);
+					}
+					if (IsAssignableFromCheck) {
+						return null;
+					}
 				}
 			} finally {
 				JniObjectReference.Dispose (ref handleClass);

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.ILLink.targets

@@ -9,6 +9,14 @@ This file contains the .NET 5-specific targets to customize ILLink
 
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
+  <ItemGroup>
+    <RuntimeHostConfigurationOption Include="Microsoft.Android.Runtime.RuntimeFeature.IsAssignableFromCheck"
+        Condition="'$(_AndroidIsAssignableFromCheck)' != ''"
+        Value="$(_AndroidIsAssignableFromCheck)"
+        Trim="true"
+    />
+  </ItemGroup>
+
   <Target Name="_PrepareLinking"
       Condition=" '$(PublishTrimmed)' == 'true' "
       AfterTargets="ComputeResolvedFilesToPublishList"

tests/Mono.Android-Tests/Android.Views/LayoutInflaterTest.cs

@@ -0,0 +1,24 @@
+using System;
+using Android.App;
+using Android.Views;
+using Java.Interop;
+
+using NUnit.Framework;
+
+namespace Android.ViewsTests;
+
+[TestFixture]
+public class LayoutInflaterTest
+{
+	[Test]
+	[Category ("Intune")]
+	public void From ()
+	{
+		Console.WriteLine ($"{nameof (LayoutInflaterTest)}: TypeManager.IsAssignableFromCheck={TypeManager.IsAssignableFromCheck}");
+
+		// See: tests\Mono.Android-Tests\Runtime-Microsoft.Android.Sdk\IsAssignableFromRemaps.xml
+		// Remapped to "net/dot/android/test/MyLayoutInflater"
+		var from = LayoutInflater.From (Application.Context);
+		Assert.IsNotNull (from);
+	}
+}

tests/Mono.Android-Tests/Mono.Android-Test.Shared.projitems

@@ -27,6 +27,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Android.Runtime\JnienvArrayMarshaling.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Android.Runtime\XmlReaderPullParserTest.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Android.Runtime\XmlReaderResourceParserTest.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Android.Views\LayoutInflaterTest.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Android.Widget\AdapterTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Java.Interop\JavaConvertTest.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Java.Interop\JavaListTest.cs" />
@@ -122,8 +123,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <AndroidJavaSource Include="$(MSBuildThisFileDirectory)java/net/dot/android/test/ValueProvider.java" />
-    <AndroidJavaSource Include="$(MSBuildThisFileDirectory)java/net/dot/android/test/Example.java" />
+    <AndroidJavaSource Include="$(MSBuildThisFileDirectory)java/net/dot/android/test/*.java" />
   </ItemGroup>
 
   <ItemGroup>

tests/Mono.Android-Tests/Runtime-Microsoft.Android.Sdk/IsAssignableFromRemaps.xml

@@ -0,0 +1,6 @@
+<replacements>
+  <replace-type
+      from="android/view/LayoutInflater"
+      to="net/dot/android/test/MyLayoutInflater"
+  />
+</replacements>

tests/Mono.Android-Tests/Runtime-Microsoft.Android.Sdk/Mono.Android.NET-Tests.csproj

@@ -45,6 +45,7 @@
   <ItemGroup>
     <TrimmerRootAssembly Include="Java.Interop-Tests" RootMode="All" />
     <_AndroidRemapMembers Include="Remaps.xml" />
+    <_AndroidRemapMembers Include="IsAssignableFromRemaps.xml" Condition=" '$(_AndroidIsAssignableFromCheck)' == 'false' " />
   </ItemGroup>
 
   <ItemGroup>

tests/Mono.Android-Tests/java/net/dot/android/test/MyLayoutInflater.java

@@ -0,0 +1,12 @@
+package net.dot.android.test;
+
+public class MyLayoutInflater extends android.view.LayoutInflater {
+    protected MyLayoutInflater (android.content.Context context) {
+        super (context);
+    }
+
+    @Override
+    public android.view.LayoutInflater cloneInContext (android.content.Context newContext) {
+        return new MyLayoutInflater (newContext);
+    }
+}