dotnet · rolfbjarne · Jan 21, 2026 · Jan 21, 2026 · Jan 21, 2026 · Jan 21, 2026
diff --git a/Directory.Build.props b/Directory.Build.props
@@ -11,6 +11,7 @@
 		<NUnitPackageVersion>4.4.0</NUnitPackageVersion>
 		<NUnitConsoleRunnerPackageVersion>3.22.0</NUnitConsoleRunnerPackageVersion>
 		<NUnit3TestAdapterPackageVersion>6.1.0</NUnit3TestAdapterPackageVersion>
+		<NUnitAnalyzersPackageVersion>4.11.2</NUnitAnalyzersPackageVersion>
 		<NUnitXmlTestLoggerPackageVersion>3.1.15</NUnitXmlTestLoggerPackageVersion>
 		<MicrosoftNETTestSdkPackageVersion>18.0.1</MicrosoftNETTestSdkPackageVersion>
 		<!-- Fix transient dependency issue found by component governance 4.7.0 -> 4.7.2 brought by Microsoft.Build package -->

@@ -149,8 +149,6 @@
 	<key>Optimizations</key>
 	<dict>
 		<!-- The key is the value to be passed to mtouch. The string is a very short description. Any IDE UI should also point to the documentation for the optimizations. -->
-		<key>inline-intptr-size</key>
-		<string>Inline IntPtr.Size</string>
 		<key>inline-runtime-arch</key>
 		<string>Inline NSObject.IsDirectBinding</string>
 		<key>dead-code-elimination</key>

@@ -173,8 +173,6 @@
 	<key>Optimizations</key>
 	<dict>
 		<!-- The key is the value to be passed to mtouch. The string is a very short description. Any IDE UI should also point to the documentation for the optimizations. -->
-		<key>inline-intptr-size</key>
-		<string>Inline IntPtr.Size</string>
 		<key>inline-runtime-arch</key>
 		<string>Inline NSObject.IsDirectBinding</string>
 		<key>dead-code-elimination</key>

@@ -94,8 +94,6 @@
 	<key>Optimizations</key>
 	<dict>
 		<!-- The key is the value to be passed to mmp. The string is a very short description. Any IDE UI should also point to the documentation for the optimizations. -->
-		<key>inline-intptr-size</key>
-		<string>Inline IntPtr.Size</string>
 		<key>inline-runtime-arch</key>
 		<string>Inline Runtime.Arch</string>
 		<key>inline-isdirectbinding</key>

@@ -123,8 +123,6 @@
 	<key>Optimizations</key>
 	<dict>
 		<!-- The key is the value to be passed to mtouch. The string is a very short description. Any IDE UI should also point to the documentation for the optimizations. -->
-		<key>inline-intptr-size</key>
-		<string>Inline IntPtr.Size</string>
 		<key>inline-runtime-arch</key>
 		<string>Inline NSObject.IsDirectBinding</string>
 		<key>dead-code-elimination</key>

@@ -1,5 +1,7 @@
 using Mono.Cecil;
 
+#nullable disable
+
 namespace Mono.Linker {
 	public static class MethodDefinitionExtensions {
 		public static bool IsDefaultConstructor (this MethodDefinition method)

@@ -33,6 +33,8 @@
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 
+#nullable disable
+
 namespace Mono.Tuner {
 
 	public static class MethodBodyRocks {

@@ -5,6 +5,8 @@
 
 using Mono.Linker;
 
+#nullable disable
+
 namespace Mono.Tuner {
 
 	public static partial class Extensions {

diff --git a/docs/website/optimizations.md b/docs/website/optimizations.md
@@ -47,44 +47,6 @@ The default behavior can be overridden by passing `--optimize=[+|-]remove-uithre
 
 [1]: /dotnet/api/UIKit.UIApplication.EnsureUIThread
 
-## Inline IntPtr.Size
-
-Inlines the constant value of `IntPtr.Size` according to the target platform.
-
-This optimization will change the following type of code:
-
-```csharp
-if (IntPtr.Size == 8) {
-    Console.WriteLine ("64-bit platform");
-} else {
-    Console.WriteLine ("32-bit platform");
-}
-```
-
-into the following (when building for a 64-bit platform):
-
-```csharp
-if (8 == 8) {
-    Console.WriteLine ("64-bit platform");
-} else {
-    Console.WriteLine ("32-bit platform");
-}
-```
-
-This optimization requires the linker to be enabled, and is only applied to
-methods with the `[BindingImpl (BindingImplOptions.Optimizable)]` attribute.
-
-By default it's enabled if targeting a single architecture, or for the
-platform assembly (**Xamarin.iOS.dll**, **Xamarin.TVOS.dll**,
-**Xamarin.WatchOS.dll** or **Xamarin.Mac.dll**).
-
-If targeting multiple architectures, this optimization will create different
-assemblies for the 32-bit version and the 64-bit version of the app, and both
-versions will have to be included in the app, effectively increasing the final
-app size instead of decreasing it.
-
-The default behavior can be overridden by passing `--optimize=[+|-]inline-intptr-size` to mtouch/mmp.
-
 ## Inline NSObject.IsDirectBinding
 
 `NSObject.IsDirectBinding` is an instance property that determines whether a
@@ -254,24 +216,12 @@ the binding code for `NFCIso15693ReadMultipleBlocksConfiguration.Range`):
 NSRange ret;
 if (IsDirectBinding) {
     if (Runtime.Arch == Arch.DEVICE) {
-        if (IntPtr.Size == 8) {
-            ret = global::ObjCRuntime.Messaging.NSRange_objc_msgSend (this.Handle, Selector.GetHandle ("range"));
-        } else {
-            global::ObjCRuntime.Messaging.NSRange_objc_msgSend_stret (out ret, this.Handle, Selector.GetHandle ("range"));
-        }
-    } else if (IntPtr.Size == 8) {
         ret = global::ObjCRuntime.Messaging.NSRange_objc_msgSend (this.Handle, Selector.GetHandle ("range"));
     } else {
         ret = global::ObjCRuntime.Messaging.NSRange_objc_msgSend (this.Handle, Selector.GetHandle ("range"));
     }
 } else {
     if (Runtime.Arch == Arch.DEVICE) {
-        if (IntPtr.Size == 8) {
-            ret = global::ObjCRuntime.Messaging.NSRange_objc_msgSendSuper (this.SuperHandle, Selector.GetHandle ("range"));
-        } else {
-            global::ObjCRuntime.Messaging.NSRange_objc_msgSendSuper_stret (out ret, this.SuperHandle, Selector.GetHandle ("range"));
-        }
-    } else if (IntPtr.Size == 8) {
         ret = global::ObjCRuntime.Messaging.NSRange_objc_msgSendSuper (this.SuperHandle, Selector.GetHandle ("range"));
     } else {
         ret = global::ObjCRuntime.Messaging.NSRange_objc_msgSendSuper (this.SuperHandle, Selector.GetHandle ("range"));

diff --git a/dotnet/targets/Xamarin.Shared.Sdk.targets b/dotnet/targets/Xamarin.Shared.Sdk.targets
@@ -245,6 +245,7 @@
 			_ResolveAppExtensionReferences;
 			_ExtendAppExtensionReferences;
 			_ComputeLinkerArguments;
+			_PrepareAssemblies;
 			_ComputeFrameworkFilesToPublish;
 			_ComputeDynamicLibrariesToPublish;
 			ComputeFilesToPublish;
@@ -730,13 +731,13 @@
 			<!--
 				IMarkHandlers which run during Mark
 			-->
-			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true'" Type="Xamarin.Linker.Steps.PreserveBlockCodeHandler" />
+			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true' And '$(PrepareAssemblies)' != 'true'" Type="Xamarin.Linker.Steps.PreserveBlockCodeHandler" />
 			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true'" Type="Xamarin.Linker.OptimizeGeneratedCodeHandler" />
 			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true'" Type="Xamarin.Linker.BackingFieldDelayHandler" />
-			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true'" Type="Xamarin.Linker.MarkIProtocolHandler" />
+			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true' And '$(PrepareAssemblies)' != 'true'" Type="Xamarin.Linker.MarkIProtocolHandler" />
 			<!-- MarkDispatcher substeps will run for all marked assemblies. -->
 			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true'" Type="Xamarin.Linker.Steps.MarkDispatcher" />
-			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true'" Type="Xamarin.Linker.Steps.PreserveSmartEnumConversionsHandler" />
+			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)" Condition="'$(_AreAnyAssembliesTrimmed)' == 'true' And '$(PrepareAssemblies)' != 'true'" Type="Xamarin.Linker.Steps.PreserveSmartEnumConversionsHandler" />
 
 			<!--
 				pre-sweep custom steps
@@ -1309,15 +1310,28 @@
 		</ItemGroup>
 	</Target>
 
-	<!-- https://github.com/dotnet/macios/issues/19037 -->
-	<!-- The trimmer will set the RootMode for the current assembly to 'EntryPoint', but that doesn't work for app extension projects, because those are library projects that don't have entry points.
-		 So here we set RootMode=Library for these cases. -->
-	<Target Name="_FixRootAssemblyForAppExtensions" AfterTargets="PrepareForILLink" Condition="'$(IsAppExtension)' == 'true'">
-		<ItemGroup>
+	<Target Name="_PostPrepareForILLinkFixups" AfterTargets="PrepareForILLink">
+		<ItemGroup Condition="'$(IsAppExtension)' == 'true'">
+			<!-- https://github.com/xamarin/xamarin-macios/issues/19037 -->
+			<!-- The trimmer will set the RootMode for the current assembly to 'EntryPoint', but that doesn't work for app extension projects, because those are library projects that don't have entry points.
+				 So here we set RootMode=Library for these cases. -->
 			<TrimmerRootAssembly Update="@(TrimmerRootAssembly)" Condition=" '%(TrimmerRootAssembly.RootMode)' == 'EntryPoint' " RootMode="Library" />
 		</ItemGroup>
+		<!-- If $(IntermediateAssembly) was modified by the AssemblyPreparer task, then we must update the TrimmerRootAssembly item group to point to the updated version of the intermediate assembly. -->
+		<!-- It turned out a bit complicated, because we want to preserve any existing metadata on the items in the TrimmerRootAssembly item group. -->
+		<ItemGroup>
+			<PreparedIntermediateAssembly Include="@(ResolvedFileToPublish)" Condition="'%(ResolvedFileToPublish.BeforePrepareAssembliesPath)' == '@(IntermediateAssembly)'" />
+		</ItemGroup>
+		<PropertyGroup>
+			<_IntermediateAssemblyProperty>@(IntermediateAssembly)</_IntermediateAssemblyProperty>
+			<_PreparedIntermediateAssemblyProperty>@(PreparedIntermediateAssembly->WithMetadataValue('BeforePrepareAssembliesPath','$(_IntermediateAssemblyProperty)'))</_PreparedIntermediateAssemblyProperty>
+		</PropertyGroup>
+		<ItemGroup Condition="@(PreparedIntermediateAssembly->Count()) &gt; 0">
+			<_PreparedRootedIntermediateAssembly Include="@(TrimmerRootAssembly->'$(_PreparedIntermediateAssemblyProperty)')" Condition="'%(Identity)' == '$(_IntermediateAssemblyProperty)'" />
+			<TrimmerRootAssembly Remove="@(IntermediateAssembly)" />
+			<TrimmerRootAssembly Include="@(_PreparedRootedIntermediateAssembly)" />
+		</ItemGroup>
 	</Target>
-
 	<Target Name="_CreateAOTDedupAssembly"
 			Condition="'$(_IsDedupEnabled)' == 'true'"
 			DependsOnTargets="_ComputeManagedAssemblyToLink"

@@ -18,6 +18,7 @@
       <MergedAssemblies Include="@(ReferenceDependencyPaths)" Condition="'%(FileName)' == 'AssemblyStripper'" />
       <MergedAssemblies Include="@(ReferencePath)" Condition="'%(FileName)' == 'MonoTargetsTasks'" />
       <MergedAssemblies Include="@(ReferencePath)" Condition="'%(FileName)' == 'Xamarin.MacDev'" />
+      <MergedAssemblies Include="@(ReferencePath)" Condition="'%(FileName)' == 'assembly-preparer'" />
       <MergedAssemblies Include="@(ReferencePath)" Condition="'%(FileName)' == 'DotNetZip'" />
       <MergedAssemblies Include="@(ReferencePath)" Condition="'%(FileName)' == 'ILLink.Tasks'" />
       <MergedAssemblies Include="@(ReferencePath)" Condition="'%(FileName)' == 'ILStrip'" />

@@ -7,8 +7,8 @@
 #nullable enable
 
 namespace Xamarin.Bundler {
-	public static partial class ErrorHelper {
-		public static ApplePlatform Platform;
+	static partial class ErrorHelper {
+		public static ApplePlatform Platform = ApplePlatform.None;
 
 		internal static string Prefix {
 			get {

@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+
+using Xamarin.Build;
+using Xamarin.Utils;
+
+#nullable enable
+
+namespace Xamarin.MacDev.Tasks {
+	public class PrepareAssemblies : XamarinTask {
+		const string ErrorPrefix = "AP";
+
+		#region Inputs
+		[Required]
+		public ITaskItem [] InputAssemblies { get; set; } = [];
+
+		public string MakeReproPath { get; set; } = "";
+
+		public string OutputDirectory { get; set; } = "";
+
+		[Required]
+		public string Registrar { get; set; } = "";
+		#endregion
+
+		#region Outputs
+		[Output]
+		public ITaskItem [] OutputAssemblies { get; set; } = [];
+		#endregion
+
+		Dictionary<AssemblyPreparerInfo, ITaskItem> map = new ();
+
+		AssemblyPreparerInfo GetAssemblyInfo (ITaskItem item)
+		{
+			var inputPath = item.ItemSpec;
+			var outputPath = Path.Combine (OutputDirectory, Path.GetFileName (inputPath));
+			var rv = new AssemblyPreparerInfo (inputPath, outputPath);
+			map [rv] = item;
+			return rv;
+		}
+
+		public override bool Execute ()
+		{
+			try {
+				var infos = InputAssemblies.Select (GetAssemblyInfo).ToArray ();
+				using var preparer = new AssemblyPreparer (infos, Platform);
+				preparer.MakeReproPath = MakeReproPath;
+				preparer.SetRegistrar (Registrar);
+				var rv = preparer.Prepare (out var exceptions);
+
+				foreach (var pe in exceptions) {
+					if (pe.Error) {
+						Log.LogError (null, $"{ErrorPrefix}{pe.Code}", null, pe.FileName ?? "MSBuild", 0, 0, 0, 0, message: pe.Message);
+						Exception? ie = pe.InnerException;
+						while (ie is not null) {
+							Log.LogMessage (MessageImportance.Low, "Inner exception: {0}\n{1}", ie.Message, ie.StackTrace);
+							ie = ie.InnerException;
+						}
+					} else {
+						Log.LogWarning (null, $"{ErrorPrefix}{pe.Code}", null, pe.FileName ?? "MSBuild", 0, 0, 0, 0, message: pe.Message);
+					}
+				}
+
+				OutputAssemblies = preparer.Assemblies.Select (v => {
+					var item = map [v];
+					item.ItemSpec = v.OutputPath;
+					item.SetMetadata ("BeforePrepareAssembliesPath", v.InputPath);
+					return item;
+				}).ToArray ();
+				return rv && !Log.HasLoggedErrors;
+			} catch (Exception e) {
+				Log.LogError ("Unexpected error while preparing assemblies: {0}", e);
+				return false;
+			}
+		}
+	}
+}