[TrimmableTypeMap] Scanner and JCW edge-case fixes

src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/JcwJavaSourceGenerator.cs

@@ -122,15 +122,28 @@ static void WriteClassDeclaration (JavaPeerInfo type, TextWriter writer)
 
 	static void WriteStaticInitializer (JavaPeerInfo type, TextWriter writer)
 	{
+		string className = JniSignatureHelper.GetJavaSimpleName (type.JavaName);
+
 		// Application and Instrumentation types cannot call registerNatives in their
-		// static initializer — the native library isn't loaded yet at that point.
-		// Their registerNatives call is emitted in the generated
-		// ApplicationRegistration.registerApplications() method instead.
+		// static initializer — the runtime isn't ready yet at that point. Emit a
+		// lazy one-time helper instead so the first managed callback can register
+		// the class just before invoking its native method.
 		if (type.CannotRegisterInStaticConstructor) {
+			writer.Write ($$"""
+	private static boolean __md_natives_registered;
+	private static synchronized void __md_registerNatives ()
+	{
+		if (!__md_natives_registered) {
+			mono.android.Runtime.registerNatives ({{className}}.class);
+			__md_natives_registered = true;
+		}
+	}
+
+
+""");
 			return;
 		}
 
-		string className = JniSignatureHelper.GetJavaSimpleName (type.JavaName);
 		writer.Write ($$"""
 	static {
 		mono.android.Runtime.registerNatives ({{className}}.class);
@@ -154,7 +167,17 @@ static void WriteConstructors (JavaPeerInfo type, TextWriter writer)
 	public {{simpleClassName}} ({{parameters}})
 	{
 		super ({{superArgs}});
+
+""");
+
+			if (!type.CannotRegisterInStaticConstructor) {
+				writer.Write ($$"""
 		if (getClass () == {{simpleClassName}}.class) nctor_{{ctor.ConstructorIndex}} ({{args}});
+
+""");
+			}
+
+			writer.Write ($$"""
 	}
 
 
@@ -197,6 +220,10 @@ static void WriteFields (JavaPeerInfo type, TextWriter writer)
 
 	static void WriteMethods (JavaPeerInfo type, TextWriter writer)
 	{
+		string registerNativesLine = type.CannotRegisterInStaticConstructor
+			? "\t\t__md_registerNatives ();\n"
+			: "";
+
 		foreach (var method in type.MarshalMethods) {
 			if (method.IsConstructor) {
 				continue;
@@ -222,7 +249,7 @@ static void WriteMethods (JavaPeerInfo type, TextWriter writer)
 	@Override
 	public {{javaReturnType}} {{method.JniName}} ({{parameters}}){{throwsClause}}
 	{
-		{{returnPrefix}}{{method.NativeCallbackName}} ({{args}});
+{{registerNativesLine}}		{{returnPrefix}}{{method.NativeCallbackName}} ({{args}});
 	}
 	public native {{javaReturnType}} {{method.NativeCallbackName}} ({{parameters}});
 
@@ -233,7 +260,7 @@ static void WriteMethods (JavaPeerInfo type, TextWriter writer)
 
 	{{access}} {{javaReturnType}} {{method.JniName}} ({{parameters}}){{throwsClause}}
 	{
-		{{returnPrefix}}{{method.NativeCallbackName}} ({{args}});
+{{registerNativesLine}}		{{returnPrefix}}{{method.NativeCallbackName}} ({{args}});
 	}
 	{{access}} native {{javaReturnType}} {{method.NativeCallbackName}} ({{parameters}});
 

src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ModelBuilder.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text;
 
 namespace Microsoft.Android.Sdk.TrimmableTypeMap;
 
@@ -13,6 +14,8 @@ namespace Microsoft.Android.Sdk.TrimmableTypeMap;
 /// </summary>
 static class ModelBuilder
 {
+	const string ProxyTypeSuffix = "_Proxy";
+
 	static readonly HashSet<string> EssentialRuntimeTypes = new (StringComparer.Ordinal) {
 		"java/lang/Object",
 		"java/lang/Class",
@@ -171,11 +174,25 @@ static void AddIfCrossAssembly (SortedSet<string> set, string? asmName, string o
 		}
 	}
 
+	static string ManagedTypeNameToProxyTypeName (string managedTypeName)
+	{
+		var builder = new StringBuilder (managedTypeName.Length + ProxyTypeSuffix.Length);
+		for (int i = 0; i < managedTypeName.Length; i++) {
+			char c = managedTypeName [i];
+			builder.Append (c == '.' || c == '+' || c == '`' ? '_' : c);
+		}
+
+		builder.Append (ProxyTypeSuffix);
+		return builder.ToString ();
+	}
+
 	static JavaPeerProxyData BuildProxyType (JavaPeerInfo peer, string jniName, HashSet<string> usedProxyNames, bool isAcw)
 	{
 		// Use managed type name for proxy naming to guarantee uniqueness across aliases
 		// (two types with the same JNI name will have different managed names).
-		var proxyTypeName = peer.ManagedTypeName.Replace ('.', '_').Replace ('+', '_') + "_Proxy";
+		// Replace generic arity markers too, because backticks would make the emitted
+		// proxy type itself look generic even though we don't emit generic parameters.
+		var proxyTypeName = ManagedTypeNameToProxyTypeName (peer.ManagedTypeName);
 
 		// Guard against name collisions (e.g., "My.Type" and "My_Type" both map to "My_Type_Proxy")
 		if (!usedProxyNames.Add (proxyTypeName)) {

src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs

@@ -6,7 +6,6 @@
 using System.Reflection.Metadata;
 using System.Reflection.Metadata.Ecma335;
 using System.Reflection.PortableExecutable;
-
 namespace Microsoft.Android.Sdk.TrimmableTypeMap;
 
 /// <summary>
@@ -732,7 +731,7 @@ bool TryResolveBaseType (TypeDefinition typeDef, AssemblyIndex index,
 	(RegisterInfo Info, string DeclaringTypeName, string DeclaringAssemblyName)? FindBaseRegisteredMethodInfo (
 		TypeDefinition typeDef, AssemblyIndex index, string methodName, MethodDefinition derivedMethod)
 	{
-		if (!TryResolveBaseType (typeDef, index, out var baseTypeDef, out var baseHandle, out var baseIndex, out var baseTypeName, out var baseAssemblyName)) {
+		if (!TryResolveBaseType (typeDef, index, out var baseTypeDef, out _, out var baseIndex, out var baseTypeName, out var baseAssemblyName)) {
 			return null;
 		}
 
@@ -760,10 +759,8 @@ bool TryResolveBaseType (TypeDefinition typeDef, AssemblyIndex index,
 			}
 		}
 
-		// Recurse up the hierarchy (stop at DoNotGenerateAcw boundary)
-		if (baseIndex.RegisterInfoByType.TryGetValue (baseHandle, out var baseRegInfo) && baseRegInfo.DoNotGenerateAcw) {
-			return null;
-		}
+		// Keep walking the full base hierarchy so overrides can inherit [Register]
+		// metadata declared above an intermediate MCW base type.
 		return FindBaseRegisteredMethodInfo (baseTypeDef, baseIndex, methodName, derivedMethod);
 	}
 
@@ -796,7 +793,7 @@ bool TryResolveBaseType (TypeDefinition typeDef, AssemblyIndex index,
 	MarshalMethodInfo? FindBaseRegisteredProperty (TypeDefinition typeDef, AssemblyIndex index,
 		string getterName, MethodDefinition derivedGetter)
 	{
-		if (!TryResolveBaseType (typeDef, index, out var baseTypeDef, out var baseHandle, out var baseIndex, out var baseTypeName, out var baseAssemblyName)) {
+		if (!TryResolveBaseType (typeDef, index, out var baseTypeDef, out _, out var baseIndex, out var baseTypeName, out var baseAssemblyName)) {
 			return null;
 		}
 
@@ -835,10 +832,8 @@ bool TryResolveBaseType (TypeDefinition typeDef, AssemblyIndex index,
 			}
 		}
 
-		// Recurse up (stop at DoNotGenerateAcw boundary)
-		if (baseIndex.RegisterInfoByType.TryGetValue (baseHandle, out var baseRegInfo) && baseRegInfo.DoNotGenerateAcw) {
-			return null;
-		}
+		// Keep walking the full base hierarchy so property overrides can inherit
+		// [Register] metadata declared above an intermediate MCW base type.
 		return FindBaseRegisteredProperty (baseTypeDef, baseIndex, getterName, derivedGetter);
 	}
 

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/JcwJavaSourceGeneratorTests.cs

@@ -138,16 +138,20 @@ public void Generate_AcwType_HasRegisterNativesStaticBlock ()
 		public void Generate_ApplicationType_SkipsRegisterNatives ()
 		{
 			var java = GenerateFixture ("my/app/MyApplication");
-			Assert.DoesNotContain ("registerNatives", java);
 			Assert.DoesNotContain ("static {", java);
+			Assert.DoesNotContain ("if (getClass () == MyApplication.class) nctor_0 ();", java);
+			AssertContainsLine ("private static synchronized void __md_registerNatives ()\n", java);
+			AssertContainsLine ("mono.android.Runtime.registerNatives (MyApplication.class);\n", java);
 		}
 
 		[Fact]
 		public void Generate_InstrumentationType_SkipsRegisterNatives ()
 		{
 			var java = GenerateFixture ("my/app/MyInstrumentation");
-			Assert.DoesNotContain ("registerNatives", java);
 			Assert.DoesNotContain ("static {", java);
+			Assert.DoesNotContain ("if (getClass () == MyInstrumentation.class) nctor_0 ();", java);
+			AssertContainsLine ("private static synchronized void __md_registerNatives ()\n", java);
+			AssertContainsLine ("mono.android.Runtime.registerNatives (MyInstrumentation.class);\n", java);
 		}
 
 	}
@@ -257,6 +261,61 @@ public void Generate_MarshalMethod_HasOverrideAndNativeDeclaration ()
 			AssertContainsLine ("public native void n_OnCreate_Landroid_os_Bundle_ (android.os.Bundle p0);\n", java);
 		}
 
+		[Fact]
+		public void Generate_OverrideAcrossIntermediateMcwBase_HasMethodStub ()
+		{
+			var java = GenerateFixture ("my/app/SelectableList");
+			AssertContainsLine ("@Override\n", java);
+			AssertContainsLine ("public void setSelection (int p0)\n", java);
+			AssertContainsLine ("n_SetSelection_I (p0);\n", java);
+			AssertContainsLine ("public native void n_SetSelection_I (int p0);\n", java);
+		}
+
+		[Fact]
+		public void Generate_OverrideAcrossGenericIntermediateMcwBase_HasMethodStub ()
+		{
+			var java = GenerateFixture ("my/app/GenericSelectableList");
+			AssertContainsLine ("@Override\n", java);
+			AssertContainsLine ("public void setSelection (int p0)\n", java);
+			AssertContainsLine ("n_SetSelection_I (p0);\n", java);
+			AssertContainsLine ("public native void n_SetSelection_I (int p0);\n", java);
+		}
+
+		[Fact]
+		public void Generate_DeferredRegistrationType_LazilyRegistersBeforeNativeCallback ()
+		{
+			var type = new JavaPeerInfo {
+				JavaName = "my/app/DeferredInstrumentation",
+				CompatJniName = "my/app/DeferredInstrumentation",
+				ManagedTypeName = "MyApp.DeferredInstrumentation",
+				ManagedTypeNamespace = "MyApp",
+				ManagedTypeShortName = "DeferredInstrumentation",
+				AssemblyName = "App",
+				BaseJavaName = "android/app/Instrumentation",
+				CannotRegisterInStaticConstructor = true,
+				MarshalMethods = new List<MarshalMethodInfo> {
+					new () {
+						JniName = "onCreate",
+						JniSignature = "(Landroid/os/Bundle;)V",
+						ManagedMethodName = "OnCreate",
+						NativeCallbackName = "n_OnCreate_Landroid_os_Bundle_",
+						Connector = "GetOnCreate_Landroid_os_Bundle_Handler",
+					},
+					new () {
+						JniName = "onStart",
+						JniSignature = "()V",
+						ManagedMethodName = "OnStart",
+						NativeCallbackName = "n_OnStart",
+						Connector = "GetOnStartHandler",
+					},
+				},
+			};
+
+			var java = GenerateToString (type);
+			AssertContainsLine ("__md_registerNatives ();\n\t\tn_OnCreate_Landroid_os_Bundle_ (p0);\n", java);
+			AssertContainsLine ("__md_registerNatives ();\n\t\tn_OnStart ();\n", java);
+		}
+
 	}
 
 	public class NestedType

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TrimmableTypeMapGeneratorTests.cs

@@ -68,6 +68,19 @@ public void Execute_WithTestFixtures_ProducesOutputs ()
 		Assert.Contains (result.GeneratedAssemblies, a => a.Name == "_TestFixtures.TypeMap");
 	}
 
+	[Fact]
+	public void Execute_CollectsDeferredRegistrationTypes_ForConcreteApplicationAndInstrumentation ()
+	{
+		using var peReader = CreateTestFixturePEReader ();
+		var result = CreateGenerator ().Execute (new List<(string, PEReader)> { ("TestFixtures", peReader) }, new Version (11, 0), new HashSet<string> ());
+
+		Assert.Contains ("my.app.MyApplication", result.ApplicationRegistrationTypes);
+		Assert.Contains ("my.app.MyInstrumentation", result.ApplicationRegistrationTypes);
+		Assert.DoesNotContain ("my.app.BaseApplication", result.ApplicationRegistrationTypes);
+		Assert.DoesNotContain ("my.app.BaseInstrumentation", result.ApplicationRegistrationTypes);
+		Assert.DoesNotContain ("my.app.IntermediateInstrumentation", result.ApplicationRegistrationTypes);
+	}
+
 	[Fact]
 	public void Execute_NullAssemblyList_Throws ()
 	{

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapAssemblyGeneratorTests.cs

@@ -246,7 +246,13 @@ public void Generate_GenericType_ThrowsNotSupportedException ()
 		using var pe = new PEReader (stream);
 		var reader = pe.GetMetadataReader ();
 		var typeNames = GetTypeRefNames (reader);
+		var generatedTypeNames = reader.TypeDefinitions
+			.Select (h => reader.GetTypeDefinition (h))
+			.Select (t => reader.GetString (t.Name))
+			.ToList ();
 		Assert.Contains ("NotSupportedException", typeNames);
+		Assert.Contains ("MyApp_Generic_GenericHolder_1_Proxy", generatedTypeNames);
+		Assert.DoesNotContain (generatedTypeNames, name => name.Contains ('`'));
 	}
 
 	[Fact]

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs

@@ -166,6 +166,7 @@ public class ProxyTypes
 		[Theory]
 		[InlineData ("java/lang/Object", "Java.Lang.Object", "Mono.Android", "Java_Lang_Object_Proxy")]
 		[InlineData ("com/example/Outer$Inner", "Com.Example.Outer.Inner", "App", "Com_Example_Outer_Inner_Proxy")]
+		[InlineData ("my/app/GenericHolder", "MyApp.Generic.GenericHolder`1", "App", "MyApp_Generic_GenericHolder_1_Proxy")]
 		public void Build_PeerWithActivation_CreatesNamedProxy (string jniName, string managedName, string asmName, string expectedProxyName)
 		{
 			var peer = MakePeerWithActivation (jniName, managedName, asmName);

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/OverrideDetectionTests.cs

@@ -102,6 +102,24 @@ public void MultipleOverloads_PicksCorrectOne ()
 		Assert.DoesNotContain (nonCtorMethods, m => m.JniName == "process" && m.JniSignature == "()V");
 	}
 
+	[Fact]
+	public void OverrideAcrossIntermediateMcwBase_Detected ()
+	{
+		var peer = FindFixtureByJavaName ("my/app/SelectableList");
+		var setSelection = Assert.Single (peer.MarshalMethods, m => m.JniName == "setSelection");
+		Assert.Equal ("(I)V", setSelection.JniSignature);
+		Assert.Equal ("GetSetSelection_IHandler", setSelection.Connector);
+	}
+
+	[Fact]
+	public void OverrideAcrossGenericIntermediateMcwBase_Detected ()
+	{
+		var peer = FindFixtureByJavaName ("my/app/GenericSelectableList");
+		var setSelection = Assert.Single (peer.MarshalMethods, m => m.JniName == "setSelection");
+		Assert.Equal ("(I)V", setSelection.JniSignature);
+		Assert.Equal ("GetSetSelection_IHandler", setSelection.Connector);
+	}
+
 	[Fact]
 	public void EmptyConnector_OverrideStillDetected ()
 	{