Enable trimmable typemap for Mono.Android.NET-Tests

Documentation/docs-mobile/messages/index.md

@@ -207,6 +207,7 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
 + [XA4247](xa4247.md): Could not resolve POM file for artifact '{artifact}'.
 + [XA4248](xa4248.md): Could not find NuGet package '{nugetId}' version '{version}' in lock file. Ensure NuGet Restore has run since this `<PackageReference>` was added.
 + [XA4235](xa4249.md): Maven artifact specification '{artifact}' is invalid. The correct format is 'group_id:artifact_id:version'.
++ [XA4250](xa4250.md): Manifest-referenced type '{type}' was not found in any scanned assembly. It may be a framework type.
 + XA4300: Native library '{library}' will not be bundled because it has an unsupported ABI.
 + [XA4301](xa4301.md): Apk already contains the item `xxx`.
 + [XA4302](xa4302.md): Unhandled exception merging \`AndroidManifest.xml\`: {ex}

Documentation/docs-mobile/messages/xa4250.md

@@ -0,0 +1,33 @@
+---
+title: .NET for Android warning XA4250
+description: XA4250 warning code
+ms.date: 04/07/2026
+f1_keywords:
+  - "XA4250"
+---
+
+# .NET for Android warning XA4250
+
+## Example message
+
+Manifest-referenced type '{0}' was not found in any scanned assembly. It may be a framework type.
+
+```text
+warning XA4250: Manifest-referenced type 'com.example.MainActivity' was not found in any scanned assembly. It may be a framework type.
+```
+
+## Issue
+
+The build found a type name in `AndroidManifest.xml`, but it could not match that name to any Java peer discovered in the app's managed assemblies.
+
+This can be expected for framework-provided types, but it can also indicate that the manifest entry does not match the name generated for a managed Android component.
+
+## Solution
+
+If the manifest entry refers to an Android framework type, this warning can usually be ignored.
+
+Otherwise:
+
+1. Verify the `android:name` value in the manifest.
+2. Ensure the managed type is included in the app build.
+3. Check for namespace, `[Register]`, or nested-type naming mismatches between the manifest and the managed type.

build-tools/automation/yaml-templates/stage-package-tests.yaml

@@ -199,10 +199,20 @@ stages:
         testName: Mono.Android.NET_Tests-CoreCLR
         project: tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj
         testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)CoreCLR.xml
-        extraBuildArgs: -p:TestsFlavor=CoreCLR -p:UseMonoRuntime=false
+        extraBuildArgs: -p:MonoAndroidTypeMapFlavor=legacy
         artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
         artifactFolder: $(DotNetTargetFramework)-CoreCLR
 
+    - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
+      parameters:
+        configuration: $(XA.Build.Configuration)
+        testName: Mono.Android.NET_Tests-CoreCLRTrimmable
+        project: tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj
+        testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)CoreCLRTrimmable.xml
+        extraBuildArgs: -p:MonoAndroidTypeMapFlavor=trimmable
+        artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
+        artifactFolder: $(DotNetTargetFramework)-CoreCLRTrimmable
+
     - template: /build-tools/automation/yaml-templates/apk-instrumentation.yaml
       parameters:
         configuration: $(XA.Build.Configuration)

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

@@ -165,7 +165,7 @@ internal static void UpdateApplicationElement (XElement app, JavaPeerInfo peer)
 		PropertyMapper.ApplyMappings (app, component.Properties, PropertyMapper.ApplicationElementMappings);
 	}
 
-	internal static void AddInstrumentation (XElement manifest, JavaPeerInfo peer)
+	internal static void AddInstrumentation (XElement manifest, JavaPeerInfo peer, string packageName)
 	{
 		string jniName = JniSignatureHelper.JniNameToJavaName (peer.JavaName);
 		var element = new XElement ("instrumentation",
@@ -176,6 +176,9 @@ internal static void AddInstrumentation (XElement manifest, JavaPeerInfo peer)
 			return;
 		}
 		PropertyMapper.ApplyMappings (element, component.Properties, PropertyMapper.InstrumentationMappings);
+		if (element.Attribute (AndroidNs + "targetPackage") is null && !string.IsNullOrEmpty (packageName)) {
+			element.SetAttributeValue (AndroidNs + "targetPackage", packageName);
+		}
 
 		manifest.Add (element);
 	}

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/ManifestGenerator.cs

@@ -73,7 +73,7 @@ class ManifestGenerator
 			}
 
 			if (peer.ComponentAttribute.Kind == ComponentKind.Instrumentation) {
-				ComponentElementBuilder.AddInstrumentation (manifest, peer);
+				ComponentElementBuilder.AddInstrumentation (manifest, peer, PackageName);
 				continue;
 			}
 
@@ -116,10 +116,7 @@ class ManifestGenerator
 		}
 
 		// Apply manifest placeholders
-		string? placeholders = ManifestPlaceholders;
-		if (placeholders is not null && placeholders.Length > 0) {
-			ApplyPlaceholders (doc, placeholders);
-		}
+		ApplyPlaceholders (doc, ManifestPlaceholders);
 
 		return (doc, providerNames);
 	}
@@ -250,8 +247,12 @@ XElement CreateRuntimeProvider (string name, string? processName, int initOrder)
 	/// Replaces ${key} placeholders in all attribute values throughout the document.
 	/// Placeholder format: "key1=value1;key2=value2"
 	/// </summary>
-	static void ApplyPlaceholders (XDocument doc, string placeholders)
+	internal static void ApplyPlaceholders (XDocument doc, string? placeholders)
 	{
+		if (placeholders.IsNullOrEmpty ()) {
+			return;
+		}
+
 		var replacements = new Dictionary<string, string> (StringComparer.Ordinal);
 		foreach (var entry in placeholders.Split (PlaceholderSeparators, StringSplitOptions.RemoveEmptyEntries)) {
 			var eqIndex = entry.IndexOf ('=');

src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/Model/TypeMapAssemblyData.cs

@@ -182,7 +182,7 @@ sealed record UcoMethodData
 /// An [UnmanagedCallersOnly] static wrapper for a constructor callback.
 /// Signature must match the full JNI native method signature (jnienv + self + ctor params)
 /// so the ABI is correct when JNI dispatches the call.
-/// Body: TrimmableNativeRegistration.ActivateInstance(self, typeof(TargetType)).
+/// Body: TrimmableTypeMap.ActivateInstance(self, typeof(TargetType)).
 /// </summary>
 sealed record UcoConstructorData
 {

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

@@ -173,7 +173,9 @@ static JavaPeerProxyData BuildProxyType (JavaPeerInfo peer, HashSet<string> used
 	{
 		// 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 = peer.ManagedTypeName.Replace ('.', '_').Replace ('+', '_').Replace ('`', '_') + "_Proxy";
 
 		// 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/Generator/PEAssemblyBuilder.cs

@@ -239,7 +239,7 @@ TypeDefinitionHandle GetOrCreateSizedType (int size)
 		int typeMethodStart = Metadata.GetRowCount (TableIndex.MethodDef) + 1;
 
 		var handle = Metadata.AddTypeDefinition (
-			TypeAttributes.NestedPrivate | TypeAttributes.ExplicitLayout | TypeAttributes.Sealed | TypeAttributes.AnsiClass,
+			TypeAttributes.NestedAssembly | TypeAttributes.ExplicitLayout | TypeAttributes.Sealed | TypeAttributes.AnsiClass,
 			default,
 			Metadata.GetOrAddString ($"__utf8_{size}"),
 			Metadata.AddTypeReference (SystemRuntimeRef,
@@ -259,7 +259,7 @@ TypeDefinitionHandle GetOrCreateSizedType (int size)
 	/// </summary>
 	public MethodDefinitionHandle EmitBody (string name, MethodAttributes attrs,
 		Action<BlobEncoder> encodeSig, Action<InstructionEncoder> emitIL)
-		=> EmitBody (name, attrs, encodeSig, emitIL, encodeLocals: null);
+		=> EmitBody (name, attrs, encodeSig, emitIL, encodeLocals: null, useBranches: false);
 
 	/// <summary>
 	/// Emits a method body and definition with optional local variable declarations.
@@ -269,9 +269,14 @@ public MethodDefinitionHandle EmitBody (string name, MethodAttributes attrs,
 	/// <see cref="BlobBuilder"/> and must write the full <c>LOCAL_SIG</c> blob (header 0x07,
 	/// compressed count, then each variable type).
 	/// </param>
+	/// <param name="useBranches">
+	/// If true, creates a <see cref="ControlFlowBuilder"/> so the emitted IL can use
+	/// <see cref="InstructionEncoder.DefineLabel"/>, <see cref="InstructionEncoder.Branch"/>,
+	/// and <see cref="InstructionEncoder.MarkLabel"/>.
+	/// </param>
 	public MethodDefinitionHandle EmitBody (string name, MethodAttributes attrs,
 		Action<BlobEncoder> encodeSig, Action<InstructionEncoder> emitIL,
-		Action<BlobBuilder>? encodeLocals)
+		Action<BlobBuilder>? encodeLocals, bool useBranches = false)
 	{
 		_sigBlob.Clear ();
 		encodeSig (new BlobEncoder (_sigBlob));
@@ -287,7 +292,11 @@ public MethodDefinitionHandle EmitBody (string name, MethodAttributes attrs,
 		}
 
 		_codeBlob.Clear ();
-		var encoder = new InstructionEncoder (_codeBlob);
+		ControlFlowBuilder? cfb = null;
+		if (useBranches) {
+			cfb = new ControlFlowBuilder ();
+		}
+		var encoder = cfb != null ? new InstructionEncoder (_codeBlob, cfb) : new InstructionEncoder (_codeBlob);
 		emitIL (encoder);
 
 		while (ILBuilder.Count % 4 != 0) {