Fix NRT annotations in src\Xamarin.Android.Build.Tasks\Utilities\ directory with proper MSBuild compatibility

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

@@ -86,6 +86,9 @@ public override bool RunTask ()
 				var parser = new ManagedResourceParser () { Log = Log, JavaPlatformDirectory = javaPlatformDirectory, ResourceFlagFile = ResourceFlagFile };
 				resources = parser.Parse (ResourceDirectory, RTxtFile ?? string.Empty, AdditionalResourceDirectories?.Select (x => x.ItemSpec), IsApplication, resource_fixup);
 			} else {
+				if (JavaResgenInputFile == null) {
+					throw new ArgumentNullException (nameof (JavaResgenInputFile));
+				}
 				var parser = new JavaResourceParser () { Log = Log };
 				resources = parser.Parse (JavaResgenInputFile, IsApplication, resource_fixup);
 			}

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

@@ -34,7 +34,7 @@ public override bool RunTask ()
 
 			var javaPlatformDirectory = JavaPlatformJarPath.IsNullOrEmpty () ? "" : Path.GetDirectoryName (JavaPlatformJarPath);
 			var parser = new FileResourceParser () { Log = Log, JavaPlatformDirectory = javaPlatformDirectory, ResourceFlagFile = ResourceFlagFile};
-			var resources = parser.Parse (ResourceDirectory, AdditionalResourceDirectories, AarLibraries, resource_fixup);
+			var resources = parser.Parse (ResourceDirectory, AdditionalResourceDirectories ?? [], AarLibraries ?? [], resource_fixup);
 
 			// only update if it changed.
 			writer.Write (RTxtFile, resources);

src/Xamarin.Android.Build.Tasks/Utilities/ACWMapGenerator.cs

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

src/Xamarin.Android.Build.Tasks/Utilities/Aapt2Daemon.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -252,7 +253,7 @@ private void Aapt2DaemonStart ()
 						}
 						// wait for the file we expect to be created. There can be a delay between
 						// the daemon saying "Done" and the file finally being written to disk.
-						if (!string.IsNullOrEmpty (job.OutputFile) && !errored) {
+						if (!job.OutputFile.IsNullOrEmpty () && !errored) {
 							while (!File.Exists (job.OutputFile)) {
 								// If either the AsyncTask.CancellationToken or tcs.Token are cancelled, we need to abort
 								tcs.Token.ThrowIfCancellationRequested ();

src/Xamarin.Android.Build.Tasks/Utilities/AndroidResource.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -91,7 +92,7 @@ static bool ResourceNeedsToBeLowerCased (string? value, string? resourceBasePath
 			// path to the msbuild's intermediate output directory and that location can be changed by the
 			// user. It's better to be safe than sorry.
 			resourceBasePath = resourceBasePath?.Trim ();
-			if (string.IsNullOrEmpty (resourceBasePath))
+			if (resourceBasePath.IsNullOrEmpty ())
 				return true;
 
 			// Avoid resource names that are all whitespace
@@ -159,7 +160,7 @@ private static void TryFixResourceAlias (XElement elem, string? resourceBasePath
 			//   <item type="layout" name="">@layout/Page1</item>
 			//   <item type="layout" name="">@drawable/Page1</item>
 			// and corrects the alias to be lower case.
-			if (elem.Name == "item" && !string.IsNullOrEmpty(elem.Value) ) {
+			if (elem.Name == "item" && !elem.Value.IsNullOrEmpty() ) {
 				string value = elem.Value.Trim();
 				Match m = r.Match (value);
 				if (m.Success) {

src/Xamarin.Android.Build.Tasks/Utilities/AndroidRuntime.cs

@@ -1,3 +1,4 @@
+#nullable enable
 namespace Xamarin.Android.Tasks;
 
 public enum AndroidRuntime

src/Xamarin.Android.Build.Tasks/Utilities/ApplicationConfig.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 
 namespace Xamarin.Android.Tasks

src/Xamarin.Android.Build.Tasks/Utilities/ApplicationConfigCLR.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 
 namespace Xamarin.Android.Tasks;

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyCompression.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.Buffers;
@@ -37,7 +38,7 @@ public AssemblyData (string sourcePath, uint descriptorIndex)
 
 			public void SetData (string sourcePath, uint descriptorIndex)
 			{
-				if (String.IsNullOrEmpty (sourcePath))
+				if (sourcePath.IsNullOrEmpty ())
 					throw new ArgumentException ("must not be null or empty", nameof (sourcePath));
 				SourcePath = sourcePath;
 				DescriptorIndex = descriptorIndex;
@@ -62,7 +63,7 @@ static CompressionResult Compress (AssemblyData data, string outputFilePath)
 
 			var outputDirectory = Path.GetDirectoryName (outputFilePath);
 
-			if (String.IsNullOrEmpty (outputDirectory))
+			if (outputDirectory.IsNullOrEmpty ())
 				throw new ArgumentException ("must not be null or empty", nameof (outputDirectory));
 
 			Directory.CreateDirectory (outputDirectory);
@@ -172,7 +173,7 @@ static string GetCompressedAssemblyOutputDirectory (ITaskItem assembly, string c
 			string subDirectory = assembly.GetMetadata ("DestinationSubDirectory");
 			string abi = MonoAndroidHelper.GetAssemblyAbi (assembly);
 
-			if (!string.IsNullOrEmpty (subDirectory) && !(subDirectory.EndsWith ($"{abi}/", StringComparison.Ordinal) || subDirectory.EndsWith ($"{abi}\\", StringComparison.Ordinal))) {
+			if (!subDirectory.IsNullOrEmpty () && !(subDirectory.EndsWith ($"{abi}/", StringComparison.Ordinal) || subDirectory.EndsWith ($"{abi}\\", StringComparison.Ordinal))) {
 				assemblyOutputDir = Path.Combine (compressedOutputDir, abi, subDirectory);
 			} else {
 				assemblyOutputDir = Path.Combine (compressedOutputDir, abi);

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyIdentityMap.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
@@ -12,7 +13,7 @@ internal class AssemblyIdentityMap
 		public void Load (string mapFile)
 		{
 			map.Clear ();
-			if (string.IsNullOrWhiteSpace (mapFile) || !File.Exists (mapFile))
+			if (mapFile.IsNullOrWhiteSpace () || !File.Exists (mapFile))
 				return;
 			foreach (var s in File.ReadLines (mapFile)) {
 				if (!map.Contains (s))

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyPackagingHelper.cs

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

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyPipeline.cs

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

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyStoreAssemblyInfo.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.IO;
 
@@ -39,7 +40,7 @@ public AssemblyStoreAssemblyInfo (string sourceFilePath, ITaskItem assembly, boo
 
 		string nameNoExt = Path.GetFileNameWithoutExtension (name);
 		string? culture = assembly.GetMetadata ("Culture");
-		if (!String.IsNullOrEmpty (culture)) {
+		if (!culture.IsNullOrEmpty ()) {
 			name = $"{culture}/{name}";
 			nameNoExt = $"{culture}/{nameNoExt}";
 		}

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyStoreBuilder.cs

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

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyStoreGenerator.Classes.cs

@@ -1,3 +1,4 @@
+#nullable enable
 namespace Xamarin.Android.Tasks;
 
 partial class AssemblyStoreGenerator

src/Xamarin.Android.Build.Tasks/Utilities/AssemblyStoreGenerator.cs

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

src/Xamarin.Android.Build.Tasks/Utilities/BundleConfigSplitConfigsChecker.cs

@@ -1,10 +1,12 @@
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
 using System.Text.Json;
 
 using Microsoft.Build.Utilities;
+using Xamarin.Android.Tasks;
 
 /// <para>
 /// When bundle configuration uses standard settings for split configs, the per-ABI library
@@ -181,7 +183,7 @@ static void TransitionState (Strings strings, Utf8JsonReader reader, Stack<Bundl
 			_                                 => throw new InvalidOperationException ($"Internal error: unsupported state transition to '{need}'")
 		};
 
-		if (!String.IsNullOrEmpty (objectName) && Xamarin.Android.Tasks.MonoAndroidHelper.StringEquals (needName, objectName)) {
+		if (!objectName.IsNullOrEmpty () && Xamarin.Android.Tasks.MonoAndroidHelper.StringEquals (needName, objectName)) {
 			state.Push (need);
 		} else {
 			state.Push (BundleConfigObject.Other);

src/Xamarin.Android.Build.Tasks/Utilities/CecilExtensions.cs

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

src/Xamarin.Android.Build.Tasks/Utilities/CompressedAssemblyInfo.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.IO;
 using Microsoft.Build.Framework;
@@ -25,7 +26,7 @@ public CompressedAssemblyInfo (uint fileSize, uint descriptorIndex, AndroidTarge
 
 		public static string GetKey (string projectFullPath)
 		{
-			if (String.IsNullOrEmpty (projectFullPath))
+			if (projectFullPath.IsNullOrEmpty ())
 				throw new ArgumentException ("must be a non-empty string", nameof (projectFullPath));
 
 			return $"{CompressedAssembliesInfoKey}:{projectFullPath}";
@@ -35,7 +36,7 @@ public static string GetDictionaryKey (ITaskItem assembly)
 		{
 			// Prefer %(DestinationSubPath) if set
 			var path = assembly.GetMetadata ("DestinationSubPath");
-			if (!string.IsNullOrEmpty (path)) {
+			if (!path.IsNullOrEmpty ()) {
 				return path;
 			}
 			// MSBuild sometimes only sets %(DestinationSubDirectory)

src/Xamarin.Android.Build.Tasks/Utilities/DSOWrapperGenerator.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -61,7 +62,7 @@ public static Config GetConfig (TaskLoggingHelper log, string androidBinUtilsDir
 
 		foreach (ITaskItem packLibDir in runtimePackLibraryDirs) {
 			string ?packRID = packLibDir.GetMetadata ("RuntimeIdentifier");
-			if (String.IsNullOrEmpty (packRID)) {
+			if (packRID.IsNullOrEmpty ()) {
 				continue;
 			}
 

src/Xamarin.Android.Build.Tasks/Utilities/ELFHelper.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using System.Collections.Concurrent;
 using System.IO;
@@ -20,7 +21,7 @@ static class ELFHelper
 	{
 		public static void AssertValidLibraryAlignment (TaskLoggingHelper log, int alignmentInPages, string path, ITaskItem? item)
 		{
-			if (String.IsNullOrEmpty (path) || !File.Exists (path)) {
+			if (path.IsNullOrEmpty () || !File.Exists (path)) {
 				return;
 			}
 
@@ -79,22 +80,22 @@ static void AssertValidLibraryAlignment (TaskLoggingHelper log, uint pageSize, s
 				}
 
 				string? metaValue = item.GetMetadata ("PathInPackage");
-				if (String.IsNullOrEmpty (metaValue)) {
+				if (metaValue.IsNullOrEmpty ()) {
 					metaValue = item.GetMetadata ("OriginalFile");
-					if (String.IsNullOrEmpty (metaValue)) {
+					if (metaValue.IsNullOrEmpty ()) {
 						metaValue = item.ItemSpec;
 					}
 				}
 				string originalFile = metaValue;
 				metaValue = item.GetMetadata ("NuGetPackageId");
-				if (String.IsNullOrEmpty (metaValue)) {
+				if (metaValue.IsNullOrEmpty ()) {
 					return (Unknown, Unknown, originalFile);
 				}
 
 				string id = metaValue;
 				string version;
 				metaValue = item.GetMetadata ("NuGetPackageVersion");
-				if (!String.IsNullOrEmpty (metaValue)) {
+				if (!metaValue.IsNullOrEmpty ()) {
 					version = metaValue;
 				} else {
 					version = Unknown;
@@ -106,7 +107,7 @@ static void AssertValidLibraryAlignment (TaskLoggingHelper log, uint pageSize, s
 
 		public static bool IsEmptyAOTLibrary (TaskLoggingHelper log, string path)
 		{
-			if (String.IsNullOrEmpty (path) || !File.Exists (path)) {
+			if (path.IsNullOrEmpty () || !File.Exists (path)) {
 				return false;
 			}
 
@@ -121,7 +122,7 @@ public static bool IsEmptyAOTLibrary (TaskLoggingHelper log, string path)
 
 		public static bool ReferencesLibrary (string libraryPath, string referencedLibraryName)
 		{
-			if (String.IsNullOrEmpty (libraryPath) || !File.Exists (libraryPath)) {
+			if (libraryPath.IsNullOrEmpty () || !File.Exists (libraryPath)) {
 				return false;
 			}
 

src/Xamarin.Android.Build.Tasks/Utilities/EnvironmentFilesParser.cs

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

src/Xamarin.Android.Build.Tasks/Utilities/Features.cs

@@ -1,3 +1,4 @@
+#nullable enable
 namespace Xamarin.Android.Tools {
 
 	static class Features {