[TrimmableTypeMap] Root manifest-referenced types as unconditional

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

@@ -69,8 +69,10 @@ public sealed record JavaPeerInfo
 	/// Types with component attributes ([Activity], [Service], etc.),
 	/// custom views from layout XML, or manifest-declared components
 	/// are unconditionally preserved (not trimmable).
+	/// May be set after scanning when the manifest references a type
+	/// that the scanner did not mark as unconditional.
 	/// </summary>
-	public bool IsUnconditional { get; init; }
+	public bool IsUnconditional { get; set; }
 
 	/// <summary>
 	/// True for Application and Instrumentation types. These types cannot call

src/Microsoft.Android.Sdk.TrimmableTypeMap/TrimmableTypeMapGenerator.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Xml.Linq;
 
 namespace Microsoft.Android.Sdk.TrimmableTypeMap;
 
@@ -12,13 +13,15 @@ namespace Microsoft.Android.Sdk.TrimmableTypeMap;
 public class TrimmableTypeMapGenerator
 {
 	readonly Action<string> log;
+	readonly Action<string>? warn;
 
-	public TrimmableTypeMapGenerator (Action<string> log)
+	public TrimmableTypeMapGenerator (Action<string> log, Action<string>? warn = null)
 	{
 		if (log is null) {
 			throw new ArgumentNullException (nameof (log));
 		}
 		this.log = log;
+		this.warn = warn;
 	}
 
 	/// <summary>
@@ -62,6 +65,8 @@ public TrimmableTypeMapResult Execute (
 			return new TrimmableTypeMapResult ([], [], allPeers);
 		}
 
+		RootManifestReferencedTypes (allPeers, manifestTemplatePath);
+
 		var generatedAssemblies = GenerateTypeMapAssemblies (allPeers, systemRuntimeVersion, assemblyPaths, outputDirectory);
 
 		// Generate JCW .java files for user assemblies + framework Implementor types.
@@ -220,4 +225,74 @@ List<string> GenerateJcwJavaSources (List<JavaPeerInfo> allPeers, string javaSou
 		log ($"Generated {files.Count} JCW Java source files.");
 		return files.ToList ();
 	}
+
+	void RootManifestReferencedTypes (List<JavaPeerInfo> allPeers, string? manifestTemplatePath)
+	{
+		if (manifestTemplatePath.IsNullOrEmpty () || !File.Exists (manifestTemplatePath)) {
+			return;
+		}
+
+		XDocument doc;
+		try {
+			doc = XDocument.Load (manifestTemplatePath);
+		} catch (Exception ex) {
+			warn?.Invoke ($"Failed to parse ManifestTemplate '{manifestTemplatePath}': {ex.Message}");
+			return;
+		}
+
+		RootManifestReferencedTypes (allPeers, doc);
+	}
+
+	internal void RootManifestReferencedTypes (List<JavaPeerInfo> allPeers, XDocument doc)
+	{
+		var root = doc.Root;
+		if (root is null) {
+			return;
+		}
+
+		XNamespace androidNs = "http://schemas.android.com/apk/res/android";
+		XName attName = androidNs + "name";
+
+		var componentNames = new HashSet<string> (StringComparer.Ordinal);
+		foreach (var element in root.Descendants ()) {
+			switch (element.Name.LocalName) {
+			case "activity":
+			case "service":
+			case "receiver":
+			case "provider":
+				var name = (string?) element.Attribute (attName);
+				if (name is not null) {
+					componentNames.Add (name);
+				}
+				break;
+			}
+		}
+
+		if (componentNames.Count == 0) {
+			return;
+		}
+
+		var peersByDotName = new Dictionary<string, List<JavaPeerInfo>> (StringComparer.Ordinal);
+		foreach (var peer in allPeers) {
+			var dotName = peer.JavaName.Replace ('/', '.').Replace ('$', '.');
+			if (!peersByDotName.TryGetValue (dotName, out var list)) {
+				list = [];
+				peersByDotName [dotName] = list;
+			}
+			list.Add (peer);
+		}
+
+		foreach (var name in componentNames) {
+			if (peersByDotName.TryGetValue (name, out var peers)) {
+				foreach (var peer in peers) {
+					if (!peer.IsUnconditional) {
+						peer.IsUnconditional = true;
+						log ($"Rooting manifest-referenced type '{name}' ({peer.ManagedTypeName}) as unconditional.");
+					}
+				}
+			} else {
+				warn?.Invoke ($"Manifest-referenced type '{name}' was not found in any scanned assembly. It may be a framework type.");
+			}
+		}
+	}
 }

src/Xamarin.Android.Build.Tasks/Tasks/GenerateTrimmableTypeMap.cs

@@ -121,7 +121,9 @@ public override bool RunTask ()
 				ApplicationJavaClass: ApplicationJavaClass);
 		}
 
-		var generator = new TrimmableTypeMapGenerator (msg => Log.LogMessage (MessageImportance.Low, msg));
+		var generator = new TrimmableTypeMapGenerator (
+			msg => Log.LogMessage (MessageImportance.Low, msg),
+			msg => Log.LogWarning (msg));
 		var result = generator.Execute (
 			assemblyPaths,
 			OutputDirectory,

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

@@ -1,4 +1,3 @@
-#nullable enable
 
 using System;
 using System.Collections.Generic;

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

@@ -151,6 +151,121 @@ TrimmableTypeMapGenerator CreateGenerator ()
 		return new TrimmableTypeMapGenerator (msg => logMessages.Add (msg));
 	}
 
+	TrimmableTypeMapGenerator CreateGenerator (List<string> warnings)
+	{
+		return new TrimmableTypeMapGenerator (msg => logMessages.Add (msg), msg => warnings.Add (msg));
+	}
+
+	[Fact]
+	public void RootManifestReferencedTypes_RootsMatchingPeers ()
+	{
+		var peers = new List<JavaPeerInfo> {
+			new JavaPeerInfo {
+				JavaName = "com/example/MyActivity", CompatJniName = "com.example.MyActivity",
+				ManagedTypeName = "MyApp.MyActivity", ManagedTypeNamespace = "MyApp", ManagedTypeShortName = "MyActivity",
+				AssemblyName = "MyApp", IsUnconditional = false,
+			},
+			new JavaPeerInfo {
+				JavaName = "com/example/MyService", CompatJniName = "com.example.MyService",
+				ManagedTypeName = "MyApp.MyService", ManagedTypeNamespace = "MyApp", ManagedTypeShortName = "MyService",
+				AssemblyName = "MyApp", IsUnconditional = false,
+			},
+		};
+
+		var doc = System.Xml.Linq.XDocument.Parse ("""
+			<?xml version="1.0" encoding="utf-8"?>
+			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example">
+			  <application>
+			    <activity android:name="com.example.MyActivity" />
+			  </application>
+			</manifest>
+			""");
+
+		var generator = CreateGenerator ();
+		generator.RootManifestReferencedTypes (peers, doc);
+
+		Assert.True (peers [0].IsUnconditional, "MyActivity should be rooted as unconditional.");
+		Assert.False (peers [1].IsUnconditional, "MyService should remain conditional.");
+		Assert.Contains (logMessages, m => m.Contains ("Rooting manifest-referenced type"));
+	}
+
+	[Fact]
+	public void RootManifestReferencedTypes_WarnsForUnresolvedTypes ()
+	{
+		var peers = new List<JavaPeerInfo> {
+			new JavaPeerInfo {
+				JavaName = "com/example/MyActivity", CompatJniName = "com.example.MyActivity",
+				ManagedTypeName = "MyApp.MyActivity", ManagedTypeNamespace = "MyApp", ManagedTypeShortName = "MyActivity",
+				AssemblyName = "MyApp",
+			},
+		};
+
+		var doc = System.Xml.Linq.XDocument.Parse ("""
+			<?xml version="1.0" encoding="utf-8"?>
+			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example">
+			  <application>
+			    <service android:name="com.example.NonExistentService" />
+			  </application>
+			</manifest>
+			""");
+
+		var warnings = new List<string> ();
+		var generator = CreateGenerator (warnings);
+		generator.RootManifestReferencedTypes (peers, doc);
+
+		Assert.Contains (warnings, w => w.Contains ("com.example.NonExistentService"));
+	}
+
+	[Fact]
+	public void RootManifestReferencedTypes_SkipsAlreadyUnconditional ()
+	{
+		var peers = new List<JavaPeerInfo> {
+			new JavaPeerInfo {
+				JavaName = "com/example/MyActivity", CompatJniName = "com.example.MyActivity",
+				ManagedTypeName = "MyApp.MyActivity", ManagedTypeNamespace = "MyApp", ManagedTypeShortName = "MyActivity",
+				AssemblyName = "MyApp", IsUnconditional = true,
+			},
+		};
+
+		var doc = System.Xml.Linq.XDocument.Parse ("""
+			<?xml version="1.0" encoding="utf-8"?>
+			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example">
+			  <application>
+			    <activity android:name="com.example.MyActivity" />
+			  </application>
+			</manifest>
+			""");
+
+		var generator = CreateGenerator ();
+		generator.RootManifestReferencedTypes (peers, doc);
+
+		Assert.True (peers [0].IsUnconditional);
+		Assert.DoesNotContain (logMessages, m => m.Contains ("Rooting manifest-referenced type"));
+	}
+
+	[Fact]
+	public void RootManifestReferencedTypes_EmptyManifest_NoChanges ()
+	{
+		var peers = new List<JavaPeerInfo> {
+			new JavaPeerInfo {
+				JavaName = "com/example/MyActivity", CompatJniName = "com.example.MyActivity",
+				ManagedTypeName = "MyApp.MyActivity", ManagedTypeNamespace = "MyApp", ManagedTypeShortName = "MyActivity",
+				AssemblyName = "MyApp",
+			},
+		};
+
+		var doc = System.Xml.Linq.XDocument.Parse ("""
+			<?xml version="1.0" encoding="utf-8"?>
+			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example">
+			</manifest>
+			""");
+
+		var generator = CreateGenerator ();
+		generator.RootManifestReferencedTypes (peers, doc);
+
+		Assert.False (peers [0].IsUnconditional);
+	}
+
 	static string GetTestFixtureAssemblyPath ()
 	{
 		var testAssemblyDir = Path.GetDirectoryName (typeof (FixtureTestBase).Assembly.Location)

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

@@ -53,7 +53,9 @@ public void InterfacePropertyImpl_DetectedWithCorrectSignature ()
 		var peer = FindFixtureByJavaName ("my/app/ImplicitPropertyImpl");
 		var getName = peer.MarshalMethods.First (m => m.JniName == "getName");
 		Assert.Equal ("()Ljava/lang/String;", getName.JniSignature);
-		Assert.Equal ("GetGetNameHandler:Android.Views.IHasNameInvoker", getName.Connector);
+		Assert.Equal ("GetGetNameHandler:Android.Views.IHasNameInvoker, TestFixtures, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null", getName.Connector);
+		Assert.Equal ("Android.Views.IHasNameInvoker", getName.DeclaringTypeName);
+		Assert.Equal ("TestFixtures", getName.DeclaringAssemblyName);
 	}
 
 	[Fact]

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/TestFixtures/TestTypes.cs

@@ -104,7 +104,7 @@ public interface IOnLongClickListener
 	[Register ("android/view/View$IHasName", "", "Android.Views.IHasNameInvoker")]
 	public interface IHasName
 	{
-		[Register ("getName", "()Ljava/lang/String;", "GetGetNameHandler:Android.Views.IHasNameInvoker")]
+		[Register ("getName", "()Ljava/lang/String;", "GetGetNameHandler:Android.Views.IHasNameInvoker, TestFixtures, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null")]
 		string? Name { get; }
 	}