Move all IO from TrimmableTypeMapGenerator to MSBuild task

The previous PR (#11034) established the pattern that TTMG has no IO
operations. The build pipeline PR regressed this by adding acw-map
writing, manifest template loading, and manifest file saving into
the generator.

Move all IO back to GenerateTrimmableTypeMap (MSBuild task):
- Load manifest template XDocument from file path
- Write merged manifest to disk via XDocument.Save()
- Write merged acw-map.txt via Files.CopyIfStreamChanged()

Refactor ManifestGenerator.Generate to return (XDocument, IList<string>)
instead of writing to disk. Add GeneratedManifest record to carry the
in-memory result.

Update ManifestGeneratorTests to work entirely in-memory (no temp dirs,
no IDisposable).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: simonrozsival

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

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using System.Xml.Linq;
 
@@ -38,11 +37,10 @@ class ManifestGenerator
 	/// Generates the merged manifest from an optional pre-loaded template and writes it to <paramref name="outputPath"/>.
 	/// Returns the list of additional content provider names (for ApplicationRegistration.java).
 	/// </summary>
-	public IList<string> Generate (
+	public (XDocument Document, IList<string> ProviderNames) Generate (
 		XDocument? manifestTemplate,
 		IReadOnlyList<JavaPeerInfo> allPeers,
-		AssemblyManifestInfo assemblyInfo,
-		string outputPath)
+		AssemblyManifestInfo assemblyInfo)
 	{
 		var doc = manifestTemplate ?? CreateDefaultManifest ();
 		var manifest = doc.Root;
@@ -122,14 +120,7 @@ public IList<string> Generate (
 			ApplyPlaceholders (doc, placeholders);
 		}
 
-		// Write output
-		var outputDir = Path.GetDirectoryName (outputPath);
-		if (outputDir is not null) {
-			Directory.CreateDirectory (outputDir);
-		}
-		doc.Save (outputPath);
-
-		return providerNames;
+		return (doc, providerNames);
 	}
 
 	XDocument CreateDefaultManifest ()

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

@@ -18,16 +18,15 @@ public TrimmableTypeMapGenerator (Action<string> log)
 
 	/// <summary>
 	/// Runs the full generation pipeline: scan assemblies, generate typemap
-	/// assemblies, generate JCW Java sources, optionally generate manifest and acw-map.
+	/// assemblies, generate JCW Java sources, and optionally generate a merged manifest.
+	/// No file IO is performed — all results are returned in memory.
 	/// </summary>
 	public TrimmableTypeMapResult Execute (
 		IReadOnlyList<(string Name, PEReader Reader)> assemblies,
 		Version systemRuntimeVersion,
 		HashSet<string> frameworkAssemblyNames,
 		ManifestConfig? manifestConfig = null,
-		string? manifestTemplatePath = null,
-		string? mergedManifestOutputPath = null,
-		string? acwMapOutputPath = null)
+		XDocument? manifestTemplate = null)
 	{
 		_ = assemblies ?? throw new ArgumentNullException (nameof (assemblies));
 		_ = systemRuntimeVersion ?? throw new ArgumentNullException (nameof (systemRuntimeVersion));
@@ -46,33 +45,18 @@ public TrimmableTypeMapResult Execute (
 		log ($"Generating JCW files for {jcwPeers.Count} types (filtered from {allPeers.Count} total).");
 		var generatedJavaSources = GenerateJcwJavaSources (jcwPeers);
 
-		string[]? additionalProviderSources = null;
+		GeneratedManifest? manifest = null;
 
 		// Generate merged AndroidManifest.xml if requested
-		if (!mergedManifestOutputPath.IsNullOrEmpty () && manifestConfig is not null) {
-			var providerSources = GenerateManifest (allPeers, assemblyManifestInfo, manifestConfig, manifestTemplatePath, mergedManifestOutputPath);
-			if (providerSources.Count > 0) {
-				additionalProviderSources = providerSources.ToArray ();
-			}
+		if (manifestConfig is not null) {
+			manifest = GenerateManifest (allPeers, assemblyManifestInfo, manifestConfig, manifestTemplate);
 		}
 
-		// Write merged acw-map.txt if requested
-		if (!acwMapOutputPath.IsNullOrEmpty ()) {
-			var acwDirectory = Path.GetDirectoryName (acwMapOutputPath);
-			if (!acwDirectory.IsNullOrEmpty ()) {
-				Directory.CreateDirectory (acwDirectory);
-			}
-			using (var writer = new StreamWriter (acwMapOutputPath)) {
-				AcwMapWriter.Write (writer, allPeers);
-			}
-			log ($"Wrote merged acw-map.txt with {allPeers.Count} types to {acwMapOutputPath}.");
-		}
-
-		return new TrimmableTypeMapResult (generatedAssemblies, generatedJavaSources, allPeers, additionalProviderSources);
+		return new TrimmableTypeMapResult (generatedAssemblies, generatedJavaSources, allPeers, manifest);
 	}
 
-	IList<string> GenerateManifest (List<JavaPeerInfo> allPeers, AssemblyManifestInfo assemblyManifestInfo,
-		ManifestConfig config, string? manifestTemplatePath, string mergedManifestOutputPath)
+	GeneratedManifest GenerateManifest (List<JavaPeerInfo> allPeers, AssemblyManifestInfo assemblyManifestInfo,
+		ManifestConfig config, XDocument? manifestTemplate)
 	{
 		string minSdk = "21";
 		if (!config.SupportedOSPlatformVersion.IsNullOrEmpty () && Version.TryParse (config.SupportedOSPlatformVersion, out var sopv)) {
@@ -103,12 +87,8 @@ IList<string> GenerateManifest (List<JavaPeerInfo> allPeers, AssemblyManifestInf
 			ApplicationJavaClass = config.ApplicationJavaClass,
 		};
 
-		XDocument? manifestTemplateDoc = null;
-		if (!manifestTemplatePath.IsNullOrEmpty () && File.Exists (manifestTemplatePath)) {
-			manifestTemplateDoc = XDocument.Load (manifestTemplatePath);
-		}
-
-		return generator.Generate (manifestTemplateDoc, allPeers, assemblyManifestInfo, mergedManifestOutputPath);
+		var (doc, providerNames) = generator.Generate (manifestTemplate, allPeers, assemblyManifestInfo);
+		return new GeneratedManifest (doc, providerNames.Count > 0 ? providerNames.ToArray () : []);
 	}
 
 	(List<JavaPeerInfo> peers, AssemblyManifestInfo manifestInfo) ScanAssemblies (IReadOnlyList<(string Name, PEReader Reader)> assemblies)

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

@@ -1,18 +1,25 @@
 using System.Collections.Generic;
 using System.IO;
+using System.Xml.Linq;
 
 namespace Microsoft.Android.Sdk.TrimmableTypeMap;
 
 public record TrimmableTypeMapResult (
 	IReadOnlyList<GeneratedAssembly> GeneratedAssemblies,
 	IReadOnlyList<GeneratedJavaSource> GeneratedJavaSources,
 	IReadOnlyList<JavaPeerInfo> AllPeers,
-	string[]? AdditionalProviderSources = null);
+	GeneratedManifest? Manifest = null);
 
 public record GeneratedAssembly (string Name, MemoryStream Content);
 
 public record GeneratedJavaSource (string RelativePath, string Content);
 
+/// <summary>
+/// The in-memory result of manifest generation: the merged document and
+/// any additional content provider class names for ApplicationRegistration.java.
+/// </summary>
+public record GeneratedManifest (XDocument Document, string[] AdditionalProviderSources);
+
 /// <summary>
 /// Configuration values for manifest generation. Passed from MSBuild properties.
 /// </summary>

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

@@ -96,19 +96,46 @@ public override bool RunTask ()
 }
 
 var generator = new TrimmableTypeMapGenerator (msg => Log.LogMessage (MessageImportance.Low, msg));
+
+XDocument? manifestTemplate = null;
+if (!ManifestTemplate.IsNullOrEmpty () && File.Exists (ManifestTemplate)) {
+	manifestTemplate = System.Xml.Linq.XDocument.Load (ManifestTemplate);
+}
+
 result = generator.Execute (
-assemblies,
-systemRuntimeVersion,
-frameworkAssemblyNames,
-manifestConfig,
-ManifestTemplate,
-MergedAndroidManifestOutput,
-AcwMapOutputFile);
+	assemblies,
+	systemRuntimeVersion,
+	frameworkAssemblyNames,
+	manifestConfig,
+	manifestTemplate);
 
 GeneratedAssemblies = WriteAssembliesToDisk (result.GeneratedAssemblies, assemblyPaths);
 GeneratedJavaFiles = WriteJavaSourcesToDisk (result.GeneratedJavaSources);
 PerAssemblyAcwMapFiles = GeneratePerAssemblyAcwMaps (result.AllPeers);
-AdditionalProviderSources = result.AdditionalProviderSources;
+
+// Write manifest to disk if generated
+if (result.Manifest is not null && !MergedAndroidManifestOutput.IsNullOrEmpty ()) {
+	var manifestDir = Path.GetDirectoryName (MergedAndroidManifestOutput);
+	if (!manifestDir.IsNullOrEmpty ()) {
+		Directory.CreateDirectory (manifestDir);
+	}
+	result.Manifest.Document.Save (MergedAndroidManifestOutput);
+	AdditionalProviderSources = result.Manifest.AdditionalProviderSources;
+}
+
+// Write merged acw-map.txt if requested
+if (!AcwMapOutputFile.IsNullOrEmpty ()) {
+	var acwDirectory = Path.GetDirectoryName (AcwMapOutputFile);
+	if (!acwDirectory.IsNullOrEmpty ()) {
+		Directory.CreateDirectory (acwDirectory);
+	}
+	using (var sw = MemoryStreamPool.Shared.CreateStreamWriter ()) {
+		AcwMapWriter.Write (sw, result.AllPeers);
+		sw.Flush ();
+		Files.CopyIfStreamChanged (sw.BaseStream, AcwMapOutputFile);
+	}
+	Log.LogDebugMessage ($"Wrote merged acw-map.txt with {result.AllPeers.Count} types to {AcwMapOutputFile}.");
+}
 } finally {
 if (result is not null) {
 foreach (var assembly in result.GeneratedAssemblies) {

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

@@ -1,6 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using System.Xml.Linq;
 using Microsoft.Android.Sdk.TrimmableTypeMap;
@@ -9,26 +7,11 @@
 
 namespace Microsoft.Android.Sdk.TrimmableTypeMap.Tests;
 
-public class ManifestGeneratorTests : IDisposable
+public class ManifestGeneratorTests
 {
 	static readonly XNamespace AndroidNs = "http://schemas.android.com/apk/res/android";
 	static readonly XName AttName = AndroidNs + "name";
 
-	string tempDir;
-
-	public ManifestGeneratorTests ()
-	{
-		tempDir = Path.Combine (Path.GetTempPath (), "ManifestGeneratorTests_" + Guid.NewGuid ().ToString ("N"));
-		Directory.CreateDirectory (tempDir);
-	}
-
-	public void Dispose ()
-	{
-		if (Directory.Exists (tempDir)) {
-			Directory.Delete (tempDir, recursive: true);
-		}
-	}
-
 	ManifestGenerator CreateDefaultGenerator () => new ManifestGenerator {
 		PackageName = "com.example.app",
 		ApplicationLabel = "My App",
@@ -39,14 +22,7 @@ public void Dispose ()
 		AndroidRuntime = "coreclr",
 	};
 
-	string OutputPath => Path.Combine (tempDir, "AndroidManifest.xml");
-
-	string WriteTemplate (string xml)
-	{
-		var path = Path.Combine (tempDir, "template.xml");
-		File.WriteAllText (path, xml);
-		return path;
-	}
+	static XDocument ParseTemplate (string xml) => XDocument.Parse (xml);
 
 	static JavaPeerInfo CreatePeer (
 		string javaName,
@@ -70,16 +46,12 @@ XDocument GenerateAndLoad (
 		ManifestGenerator gen,
 		IReadOnlyList<JavaPeerInfo>? peers = null,
 		AssemblyManifestInfo? assemblyInfo = null,
-		string? templatePath = null)
+		XDocument? template = null)
 	{
 		peers ??= [];
 		assemblyInfo ??= new AssemblyManifestInfo ();
-		XDocument? template = null;
-		if (!string.IsNullOrEmpty (templatePath) && File.Exists (templatePath)) {
-			template = XDocument.Load (templatePath);
-		}
-		gen.Generate (template, peers, assemblyInfo, OutputPath);
-		return XDocument.Load (OutputPath);
+		var (doc, _) = gen.Generate (template, peers, assemblyInfo);
+		return doc;
 	}
 
 	[Fact]
@@ -305,7 +277,7 @@ public void RuntimeProvider_Added ()
 	public void TemplateManifest_Preserved ()
 	{
 		var gen = CreateDefaultGenerator ();
-		var template = WriteTemplate (
+		var template = ParseTemplate (
 			"""
 			<?xml version="1.0" encoding="utf-8"?>
 			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.app">
@@ -314,7 +286,7 @@ public void TemplateManifest_Preserved ()
 			</manifest>
 			""");
 
-		var doc = GenerateAndLoad (gen, templatePath: template);
+		var doc = GenerateAndLoad (gen, template: template);
 		var app = doc.Root?.Element ("application");
 
 		Assert.Equal ("false", (string?)app?.Attribute (AndroidNs + "allowBackup"));
@@ -384,7 +356,7 @@ public void ManifestPlaceholders_Replaced ()
 		var gen = CreateDefaultGenerator ();
 		gen.ManifestPlaceholders = "myAuthority=com.example.auth;myKey=12345";
 
-		var template = WriteTemplate (
+		var template = ParseTemplate (
 			"""
 			<?xml version="1.0" encoding="utf-8"?>
 			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.app">
@@ -395,7 +367,7 @@ public void ManifestPlaceholders_Replaced ()
 			</manifest>
 			""");
 
-		var doc = GenerateAndLoad (gen, templatePath: template);
+		var doc = GenerateAndLoad (gen, template: template);
 		var provider = doc.Root?.Element ("application")?.Elements ("provider")
 			.FirstOrDefault (p => (string?)p.Attribute (AndroidNs + "name") == "com.example.MyProvider");
 		Assert.Equal ("com.example.auth", (string?)provider?.Attribute (AndroidNs + "authorities"));
@@ -434,7 +406,7 @@ public void AbstractTypes_Skipped ()
 	public void ExistingType_NotDuplicated ()
 	{
 		var gen = CreateDefaultGenerator ();
-		var template = WriteTemplate (
+		var template = ParseTemplate (
 			"""
 			<?xml version="1.0" encoding="utf-8"?>
 			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.app">
@@ -449,7 +421,7 @@ public void ExistingType_NotDuplicated ()
 			Properties = new Dictionary<string, object?> { ["Label"] = "New Label" },
 		});
 
-		var doc = GenerateAndLoad (gen, [peer], templatePath: template);
+		var doc = GenerateAndLoad (gen, [peer], template: template);
 		var activities = doc.Root?.Element ("application")?.Elements ("activity")
 			.Where (a => (string?)a.Attribute (AttName) == "com.example.app.ExistingActivity")
 			.ToList ();
@@ -556,7 +528,7 @@ public void AssemblyLevel_Application ()
 	public void AssemblyLevel_Deduplication ()
 	{
 		var gen = CreateDefaultGenerator ();
-		var template = WriteTemplate (
+		var template = ParseTemplate (
 			"""
 			<?xml version="1.0" encoding="utf-8"?>
 			<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.app">
@@ -573,7 +545,7 @@ public void AssemblyLevel_Deduplication ()
 		info.UsesLibraries.Add (new UsesLibraryInfo { Name = "org.apache.http.legacy" });
 		info.MetaData.Add (new MetaDataInfo { Name = "existing.key", Value = "new_value" });
 
-		var doc = GenerateAndLoad (gen, assemblyInfo: info, templatePath: template);
+		var doc = GenerateAndLoad (gen, assemblyInfo: info, template: template);
 
 		var cameraPerms = doc.Root?.Elements ("uses-permission")
 			.Where (p => (string?)p.Attribute (AttName) == "android.permission.CAMERA")