From 1aef5e7da6c0e7d9d06317a4ff9ef1cd35fbc345 Mon Sep 17 00:00:00 2001
From: Sven Boemer <sbomer@gmail.com>
Date: Wed, 13 May 2026 17:13:37 -0700
Subject: [PATCH 1/4] [NativeAOT] Make workload linker the default for
 NativeAOT builds

Change _AndroidUseWorkloadNativeLinker default from false to true so
NativeAOT builds use the workload-provided linker and sysroot by default,
removing the NDK requirement.

Update SetRuntime(NativeAOT) to set _SkipNdkResolution=true so all
existing NativeAOT tests exercise the NDK-free workload linker path.

Update NativeAotBuildTests with three tests covering the full matrix:
- BuildNativeAot_WithoutNdk: workload linker (default), no NDK -> succeeds
- BuildNativeAot_WithNdkLinker: opt-out to NDK linker, with NDK -> succeeds
- BuildNativeAot_WithoutNdk_WorkloadLinkerDisabled_Fails: opt-out, no NDK -> fails

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Assisted-by: Claude:claude-opus-4.6-1m
---
 .../Microsoft.Android.Sdk.NativeAOT.targets   |  2 +-
 .../NativeAotBuildTests.cs                    | 35 ++++++++++++++-----
 .../Utilities/ProjectExtensions.cs            |  1 +
 3 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets b/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets
index 53f327d7e73..6ad1523d89d 100644
--- a/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets
+++ b/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets
@@ -299,7 +299,7 @@ This file contains the NativeAOT-specific MSBuild logic for .NET for Android.
       Outputs="$(NativeOutputPath)$(NativeBinaryPrefix)$(TargetName).so">
     <PropertyGroup>
       <_AndroidNativeAotSharedLibrary>$(NativeOutputPath)$(NativeBinaryPrefix)$(TargetName).so</_AndroidNativeAotSharedLibrary>
-      <_AndroidUseWorkloadNativeLinker Condition=" '$(_AndroidUseWorkloadNativeLinker)' == '' ">false</_AndroidUseWorkloadNativeLinker>
+      <_AndroidUseWorkloadNativeLinker Condition=" '$(_AndroidUseWorkloadNativeLinker)' == '' ">true</_AndroidUseWorkloadNativeLinker>
     </PropertyGroup>
 
     <!-- Resolve the runtime pack native directory for workload-provided linker dependencies.
diff --git a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/NativeAotBuildTests.cs b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/NativeAotBuildTests.cs
index 93fb50e65ed..1c176bec323 100644
--- a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/NativeAotBuildTests.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/NativeAotBuildTests.cs
@@ -12,7 +12,7 @@ namespace Xamarin.Android.Build.Tests
 	public class NativeAotBuildTests : BaseTest
 	{
 		[Test]
-		public void BuildNativeAot_WithoutNdk_Fails ()
+		public void BuildNativeAot_WithoutNdk ()
 		{
 			var proj = new XamarinAndroidApplicationProject {
 				IsRelease = true,
@@ -20,28 +20,45 @@ public void BuildNativeAot_WithoutNdk_Fails ()
 			proj.SetRuntime (AndroidRuntime.NativeAOT);
 
 			using var builder = CreateApkBuilder ();
-			builder.ThrowOnBuildFailure = false;
-			Assert.IsFalse (
-				builder.Build (proj, parameters: new [] { "_SkipNdkResolution=true" }),
-				"Build should have failed without NDK."
+			Assert.IsTrue (
+				builder.Build (proj),
+				"Build should succeed without NDK (workload linker is the default)."
 			);
 		}
 
 		[Test]
-		public void BuildNativeAot_WithWorkloadLinker_WithoutNdk ()
+		public void BuildNativeAot_WithNdkLinker ()
 		{
 			var proj = new XamarinAndroidApplicationProject {
 				IsRelease = true,
 			};
 			proj.SetRuntime (AndroidRuntime.NativeAOT);
+			proj.SetProperty ("_SkipNdkResolution", "false");
 
 			using var builder = CreateApkBuilder ();
 			Assert.IsTrue (
 				builder.Build (proj, parameters: new [] {
-					"_SkipNdkResolution=true",
-					"_AndroidUseWorkloadNativeLinker=true",
+					"_AndroidUseWorkloadNativeLinker=false",
+				}),
+				"Build should succeed with NDK linker."
+			);
+		}
+
+		[Test]
+		public void BuildNativeAot_WithoutNdk_WorkloadLinkerDisabled_Fails ()
+		{
+			var proj = new XamarinAndroidApplicationProject {
+				IsRelease = true,
+			};
+			proj.SetRuntime (AndroidRuntime.NativeAOT);
+
+			using var builder = CreateApkBuilder ();
+			builder.ThrowOnBuildFailure = false;
+			Assert.IsFalse (
+				builder.Build (proj, parameters: new [] {
+					"_AndroidUseWorkloadNativeLinker=false",
 				}),
-				"Build should succeed with workload linker and no NDK."
+				"Build should fail without NDK when workload linker is disabled."
 			);
 		}
 	}
diff --git a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Utilities/ProjectExtensions.cs b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Utilities/ProjectExtensions.cs
index 554d2e3ecaf..41e701a39e2 100644
--- a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Utilities/ProjectExtensions.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Utilities/ProjectExtensions.cs
@@ -24,6 +24,7 @@ public static void SetRuntime (this XamarinAndroidApplicationProject project, An
 			return;
 		}
 		project.SetPublishAot (true);
+		project.SetProperty ("_SkipNdkResolution", "true");
 		EnablePreviewFeaturesIfNeeded (project, runtime);
 	}
 

From d9188453ca5d74832b916a6ba544468586ae8f99 Mon Sep 17 00:00:00 2001
From: Sven Boemer <sbomer@gmail.com>
Date: Wed, 13 May 2026 17:34:54 -0700
Subject: [PATCH 2/4] Move _AndroidUseWorkloadNativeLinker default to top-level
 PropertyGroup

The default was set inside _AndroidLinkNativeAotSharedLibrary, but
SetIlcToolchainPath in _AndroidBeforeIlcCompile runs earlier and
checks the property. With the default set too late, ILC would use
the NDK bin dir instead of AndroidBinUtilsDirectory when the property
was not explicitly set.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Assisted-by: Claude:claude-opus-4.6-1m
---
 .../targets/Microsoft.Android.Sdk.NativeAOT.targets             | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets b/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets
index 6ad1523d89d..3b7c6203ad6 100644
--- a/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets
+++ b/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets
@@ -15,6 +15,7 @@ This file contains the NativeAOT-specific MSBuild logic for .NET for Android.
   <!-- Default property values for NativeAOT -->
   <PropertyGroup>
     <_AndroidRuntimePackRuntime>NativeAOT</_AndroidRuntimePackRuntime>
+    <_AndroidUseWorkloadNativeLinker Condition=" '$(_AndroidUseWorkloadNativeLinker)' == '' ">true</_AndroidUseWorkloadNativeLinker>
     <_AndroidJcwCodegenTarget Condition=" '$(_AndroidJcwCodegenTarget)' == '' ">JavaInterop1</_AndroidJcwCodegenTarget>
     <_AndroidTypeMapImplementation Condition=" '$(_AndroidTypeMapImplementation)' == '' ">managed</_AndroidTypeMapImplementation>
     <!-- .NET SDK gives: error NETSDK1191: A runtime identifier for the property 'PublishAot' couldn't be inferred. Specify a rid explicitly. -->
@@ -299,7 +300,6 @@ This file contains the NativeAOT-specific MSBuild logic for .NET for Android.
       Outputs="$(NativeOutputPath)$(NativeBinaryPrefix)$(TargetName).so">
     <PropertyGroup>
       <_AndroidNativeAotSharedLibrary>$(NativeOutputPath)$(NativeBinaryPrefix)$(TargetName).so</_AndroidNativeAotSharedLibrary>
-      <_AndroidUseWorkloadNativeLinker Condition=" '$(_AndroidUseWorkloadNativeLinker)' == '' ">true</_AndroidUseWorkloadNativeLinker>
     </PropertyGroup>
 
     <!-- Resolve the runtime pack native directory for workload-provided linker dependencies.

From 59602244d4a1df4bd2d4ed18ed30a7b91c2d75f3 Mon Sep 17 00:00:00 2001
From: Sven Boemer <sbomer@gmail.com>
Date: Wed, 13 May 2026 17:50:59 -0700
Subject: [PATCH 3/4] Skip NDK dependency for NativeAOT when using workload
 linker

Update _NdkRequired in GetAndroidDependencies to only require NDK for
PublishAot when _AndroidUseWorkloadNativeLinker is not enabled. Update
NativeAotRequiresNdk test to explicitly opt out of the workload linker
so it continues to verify NDK is required on the old path.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Assisted-by: Claude:claude-opus-4.6-1m
---
 .../Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs    | 3 ++-
 src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs
index afff1ba0c0a..14dc44908e1 100644
--- a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs
@@ -206,6 +206,7 @@ public void NativeAotRequiresNdk ()
 				IsRelease = true,
 			};
 			proj.SetRuntime (AndroidRuntime.NativeAOT);
+			proj.SetProperty ("_AndroidUseWorkloadNativeLinker", "false");
 			using (var builder = CreateApkBuilder ()) {
 				builder.Verbosity = LoggerVerbosity.Detailed;
 				builder.Target = "GetAndroidDependencies";
@@ -215,7 +216,7 @@ public void NativeAotRequiresNdk ()
 					.SkipWhile (x => !x.StartsWith ("Task \"CalculateProjectDependencies\"", StringComparison.Ordinal))
 					.SkipWhile (x => !x.StartsWith ("Output Item(s):", StringComparison.Ordinal))
 					.TakeWhile (x => !x.StartsWith ("Done executing task \"CalculateProjectDependencies\"", StringComparison.Ordinal));
-				StringAssertEx.Contains ("ndk-bundle", taskOutput, "ndk-bundle should be a dependency for NativeAOT.");
+				StringAssertEx.Contains ("ndk-bundle", taskOutput, "ndk-bundle should be a dependency for NativeAOT without workload linker.");
 			}
 		}
 
diff --git a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
index 5674bb72ff2..539ee59f193 100644
--- a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
+++ b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
@@ -2860,7 +2860,7 @@ because xbuild doesn't support framework reference assemblies.
   <PropertyGroup>
     <_ProjectAndroidManifest>$(ProjectDir)$(AndroidManifest)</_ProjectAndroidManifest>
     <_NdkRequired Condition="'$(EnableLLVM)' == 'True'">true</_NdkRequired>
-    <_NdkRequired Condition="'$(PublishAot)' == 'true'">true</_NdkRequired>
+    <_NdkRequired Condition="'$(PublishAot)' == 'true' and '$(_AndroidUseWorkloadNativeLinker)' != 'true'">true</_NdkRequired>
     <_NdkRequired Condition="'$(_NdkRequired)' == ''">false</_NdkRequired>
   </PropertyGroup>
   <Error Text="AndroidManifest file does not exist" Condition="'$(_ProjectAndroidManifest)'!='' And !Exists ('$(_ProjectAndroidManifest)')"/>

From c37a7a9c82d5b45a3024463ee4c13ed5d127f6b7 Mon Sep 17 00:00:00 2001
From: Sven Boemer <sbomer@gmail.com>
Date: Wed, 13 May 2026 19:07:55 -0700
Subject: [PATCH 4/4] Fix GetDependencyNdkRequiredConditions test for NativeAOT

Skip EnableLLVM and AndroidEnableProfiledAot for NativeAOT (Mono
concepts not applicable). AotAssemblies+NativeAOT continues to run
and correctly asserts NDK is not required.

Fix NativeAotRequiresNdk to override _SkipNdkResolution=false so
NDK resolution runs and the ndk-bundle dependency can be detected
when testing the opt-out path.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Assisted-by: Claude:claude-opus-4.6-1m
---
 .../AndroidDependenciesTests.cs                        | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs
index 14dc44908e1..c7cec2c7072 100644
--- a/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidDependenciesTests.cs
@@ -167,14 +167,13 @@ public void GetDependencyNdkRequiredConditions (string property, bool ndkRequire
 				Assert.Ignore ("CoreCLR doesn't support AOT, it doesn't ever require the NDK");
 			}
 
-			// NativeAOT doesn't support profiled AOT
+			// NativeAOT doesn't support profiled AOT or EnableLLVM (Mono concepts)
 			if (runtime == AndroidRuntime.NativeAOT && property == "AndroidEnableProfiledAot") {
 				Assert.Ignore ("NativeAOT doesn't support profiled AOT");
 			}
 
-			// NativeAOT always requires the NDK (PublishAot=true), so ndkRequired=false cases don't apply
-			if (runtime == AndroidRuntime.NativeAOT && !ndkRequired) {
-				Assert.Ignore ("NativeAOT always requires NDK via PublishAot=true");
+			if (runtime == AndroidRuntime.NativeAOT && property == "EnableLLVM") {
+				Assert.Ignore ("EnableLLVM is not applicable to NativeAOT");
 			}
 
 			var proj = new XamarinAndroidApplicationProject {
@@ -200,13 +199,14 @@ public void GetDependencyNdkRequiredConditions (string property, bool ndkRequire
 		}
 
 		[Test]
-		public void NativeAotRequiresNdk ()
+		public void NativeAotRequiresNdk_WhenWorkloadLinkerDisabled ()
 		{
 			var proj = new XamarinAndroidApplicationProject {
 				IsRelease = true,
 			};
 			proj.SetRuntime (AndroidRuntime.NativeAOT);
 			proj.SetProperty ("_AndroidUseWorkloadNativeLinker", "false");
+			proj.SetProperty ("_SkipNdkResolution", "false");
 			using (var builder = CreateApkBuilder ()) {
 				builder.Verbosity = LoggerVerbosity.Detailed;
 				builder.Target = "GetAndroidDependencies";