[Xamarin.Android.Build.Tasks] don't set $(UseMonoRuntime) by default

Documentation/docs-mobile/messages/xa1040.md

@@ -8,24 +8,23 @@ ms.date: 02/24/2025
 ## Example messages
 
 ```
-warning XA1040: The CoreCLR runtime on Android is an experimental feature and not yet suitable for production use. File issues at: https://github.com/dotnet/android/issues
 warning XA1040: The NativeAOT runtime on Android is an experimental feature and not yet suitable for production use. File issues at: https://github.com/dotnet/android/issues
 ```
 
 ## Issue
 
-MonoVM is the default, supported runtime for .NET for Android.
+CoreCLR is the default, supported runtime for .NET for Android. Mono is also supported.
 
-Other runtimes are currently experimental, such as:
+You can opt into other runtimes via:
 
-* CoreCLR, used via `$(UseMonoRuntime)=false`
+* CoreCLR, default
+* MonoVM, used via `$(UseMonoRuntime)=true`
 * NativeAOT, used via `$(PublishAot)=true`
 
 ## Solution
 
 To silence this warning, you can either:
 
-* Use MonoVM by removing `$(UseMonoRuntime)=false` or
-  `$(PublishAot)=true` from your project file.
+* Use CoreCLR by removing `$(PublishAot)=true` from your project file.
 
 * Set `$(EnablePreviewFeatures)` to `true` in your project file.

build-tools/automation/yaml-templates/stage-package-tests.yaml

@@ -86,7 +86,7 @@ stages:
         testName: Mono.Android.NET_Tests-Interpreter
         project: tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj
         testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)Interpreter.xml
-        extraBuildArgs: -p:TestsFlavor=Interpreter -p:UseInterpreter=True
+        extraBuildArgs: -p:TestsFlavor=Interpreter -p:UseInterpreter=True -p:UseMonoRuntime=true
         artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
         artifactFolder: $(DotNetTargetFramework)-Interpreter
 
@@ -154,7 +154,7 @@ stages:
         testName: Mono.Android.NET_Tests-NoAot
         project: tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj
         testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)NoAot.xml
-        extraBuildArgs: -p:TestsFlavor=NoAot -p:RunAOTCompilation=false
+        extraBuildArgs: -p:TestsFlavor=NoAot -p:RunAOTCompilation=false -p:UseMonoRuntime=true
         artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
         artifactFolder: $(DotNetTargetFramework)-NoAot
 
@@ -164,7 +164,7 @@ stages:
         testName: Mono.Android.NET_Tests-TrimModePartial
         project: tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj
         testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)TrimModePartial.xml
-        extraBuildArgs: -p:TestsFlavor=TrimModePartial -p:TrimMode=partial
+        extraBuildArgs: -p:TestsFlavor=TrimModePartial -p:TrimMode=partial -p:UseMonoRuntime=true
         artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
         artifactFolder: $(DotNetTargetFramework)-TrimModePartial
 
@@ -174,7 +174,7 @@ stages:
         testName: Mono.Android.NET_Tests-AotLlvm
         project: tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj
         testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)AotLlvm.xml
-        extraBuildArgs: -p:TestsFlavor=AotLlvm -p:EnableLLVM=true -p:AndroidEnableProfiledAot=false
+        extraBuildArgs: -p:TestsFlavor=AotLlvm -p:EnableLLVM=true -p:AndroidEnableProfiledAot=false -p:UseMonoRuntime=true
         artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
         artifactFolder: $(DotNetTargetFramework)-AotLlvm
 
@@ -184,7 +184,7 @@ stages:
         testName: Mono.Android.NET_Tests-IsAssignableFrom
         project: tests/Mono.Android-Tests/Mono.Android-Tests/Mono.Android.NET-Tests.csproj
         testResultsFiles: TestResult-Mono.Android.NET_Tests-$(XA.Build.Configuration)IsAssignableFrom.xml
-        extraBuildArgs: -p:TestsFlavor=IsAssignableFrom -p:IncludeCategories=Intune -p:_AndroidIsAssignableFromCheck=false
+        extraBuildArgs: -p:TestsFlavor=IsAssignableFrom -p:IncludeCategories=Intune -p:_AndroidIsAssignableFromCheck=false -p:UseMonoRuntime=true
         artifactSource: bin/Test$(XA.Build.Configuration)/$(DotNetTargetFramework)-android/Mono.Android.NET_Tests-Signed.aab
         artifactFolder: $(DotNetTargetFramework)-IsAssignableFrom
 

build-tools/scripts/TestApks.targets

@@ -18,7 +18,7 @@
 
   <PropertyGroup>
     <!-- APK tests might run on 32-bit emulators -->
-    <RuntimeIdentifiers Condition=" '$(RuntimeIdentifier)' == '' and '$(PublishAot)' != 'true' and '$(UseMonoRuntime)' != 'false' ">android-arm64;android-x86;android-x64;</RuntimeIdentifiers>
+    <RuntimeIdentifiers Condition=" '$(RuntimeIdentifier)' == '' and '$(PublishAot)' != 'true' and '$(UseMonoRuntime)' == 'true' ">android-arm64;android-x86;android-x64;</RuntimeIdentifiers>
     <TestAvdApiLevel Condition=" '$(TestAvdApiLevel)' == '' ">29</TestAvdApiLevel>
     <TestAvdAbi Condition=" '$(TestAvdAbi)' == '' and '$(HostOS)' == 'Darwin' and  '$(HostOSArchitecture)' == 'Arm64' ">arm64-v8a</TestAvdAbi>
     <TestAvdAbi Condition=" '$(TestAvdAbi)' == '' ">x86_64</TestAvdAbi>

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.DefaultProperties.targets

@@ -22,11 +22,9 @@
       See: https://github.com/dotnet/sdk/blob/955c0fc7b06e2fa34bacd076ed39f61e4fb61716/src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Publish.targets#L16
     -->
     <_GetChildProjectCopyToPublishDirectoryItems>false</_GetChildProjectCopyToPublishDirectoryItems>
-    <UseMonoRuntime Condition=" '$(PublishAot)' == 'true' and '$(UseMonoRuntime)' == '' ">false</UseMonoRuntime>
-    <UseMonoRuntime Condition=" '$(UseMonoRuntime)' == '' ">true</UseMonoRuntime>
-    <_AndroidRuntime Condition=" '$(PublishAot)' == 'true' and '$(UseMonoRuntime)' != 'true' ">NativeAOT</_AndroidRuntime>
-    <_AndroidRuntime Condition=" '$(PublishAot)' != 'true' and '$(UseMonoRuntime)' != 'true' ">CoreCLR</_AndroidRuntime>
-    <_AndroidRuntime Condition=" '$(_AndroidRuntime)' == '' ">MonoVM</_AndroidRuntime>
+    <_AndroidRuntime Condition=" '$(PublishAot)' == 'true' ">NativeAOT</_AndroidRuntime>
+    <_AndroidRuntime Condition=" '$(PublishAot)' != 'true' and '$(UseMonoRuntime)' == 'true' ">MonoVM</_AndroidRuntime>
+    <_AndroidRuntime Condition=" '$(_AndroidRuntime)' == '' ">CoreCLR</_AndroidRuntime>
     <PublishAotUsingRuntimePack Condition=" '$(PublishAotUsingRuntimePack)' == '' and '$(_AndroidRuntime)' == 'NativeAOT' ">true</PublishAotUsingRuntimePack>
 
     <!-- Use $(AndroidMinimumSupportedApiLevel) for $(SupportedOSPlatformVersion) if unset -->

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AotTests.cs

@@ -69,6 +69,8 @@ public void BuildBasicApplicationReleaseProfiledAot ([Values (true, false)] bool
 				IsRelease = true,
 				AndroidEnableProfiledAot = true,
 			};
+			// Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
 			proj.SetProperty ("EnableLLVM", enableLLVM.ToString ());
 			proj.SetProperty (proj.ActiveConfigurationProperties, "AndroidExtraAotOptions", "--verbose");
 			using var b = CreateApkBuilder ();
@@ -84,6 +86,8 @@ public void BuildBasicApplicationReleaseWithCustomAotProfile ()
 				IsRelease = true,
 				AndroidEnableProfiledAot = true,
 			};
+			// A Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
 			proj.SetProperty (proj.ActiveConfigurationProperties, "AndroidExtraAotOptions", "--verbose");
 
 			byte [] custom_aot_profile = XamarinAndroidCommonProject.GetResourceContents ("Xamarin.ProjectTools.Resources.Base.custom.aotprofile");
@@ -102,32 +106,60 @@ public void BuildBasicApplicationReleaseProfiledAotWithoutDefaultProfile ()
 				IsRelease = true,
 				AndroidEnableProfiledAot = true,
 			};
+			// Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
 			proj.SetProperty (proj.ActiveConfigurationProperties, "AndroidUseDefaultAotProfile", "false");
 			using var b = CreateApkBuilder ();
 			b.Verbosity = LoggerVerbosity.Detailed;
 			Assert.IsTrue (b.Build (proj), "Build should have succeeded.");
 			StringAssertEx.DoesNotContainRegex (@$"Using profile data file.*dotnet\.aotprofile", b.LastBuildOutput, "Should not use default AOT profile", RegexOptions.IgnoreCase);
 		}
 
+		static IEnumerable<object[]> Get_BuildAotApplicationWithSpecialCharactersInProjectData ()
+		{
+			var ret = new List<object[]> ();
+
+			foreach (AndroidRuntime runtime in new[] { AndroidRuntime.MonoVM, AndroidRuntime.CoreCLR }) {
+				AddTestData ("テスト", false, false, runtime);
+				AddTestData ("テスト", true, true, runtime);
+				AddTestData ("テスト", true, false, runtime);
+				AddTestData ("随机生成器", false, false, runtime);
+				AddTestData ("随机生成器", true, true, runtime);
+				AddTestData ("随机生成器", true, false, runtime);
+				AddTestData ("中国", false, false, runtime);
+				AddTestData ("中国", true, true, runtime);
+				AddTestData ("中国", true, false, runtime);
+			}
+
+			return ret;
+
+			void AddTestData (string testName, bool isRelease, bool aot, AndroidRuntime runtime)
+			{
+				ret.Add (new object[] {
+					testName,
+					isRelease,
+					aot,
+					runtime,
+				});
+			}
+		}
+
 		[Test]
-		[TestCase ("テスト", false, false)]
-		[TestCase ("テスト", true, true)]
-		[TestCase ("テスト", true, false)]
-		[TestCase ("随机生成器", false, false)]
-		[TestCase ("随机生成器", true, true)]
-		[TestCase ("随机生成器", true, false)]
-		[TestCase ("中国", false, false)]
-		[TestCase ("中国", true, true)]
-		[TestCase ("中国", true, false)]
-		public void BuildAotApplicationWithSpecialCharactersInProject (string testName, bool isRelease, bool aot)
+		[TestCaseSource (nameof (Get_BuildAotApplicationWithSpecialCharactersInProjectData))]
+		public void BuildAotApplicationWithSpecialCharactersInProject (string testName, bool isRelease, bool aot, AndroidRuntime runtime)
 		{
+			if (aot && runtime == AndroidRuntime.CoreCLR) {
+				Assert.Ignore ("AOT + CoreCLR == NativeAOT; Not supported yet here");
+				return;
+			}
+
 			var rootPath = Path.Combine (Root, "temp", TestName);
 			var proj = new XamarinAndroidApplicationProject () {
 				ProjectName = testName,
 				IsRelease = isRelease,
 				AotAssemblies = aot,
 			};
-			proj.SetAndroidSupportedAbis ("armeabi-v7a",  "arm64-v8a", "x86", "x86_64");
+			proj.SetRuntime (runtime);
 			using (var builder = CreateApkBuilder (Path.Combine (rootPath, proj.ProjectName))){
 				Assert.IsTrue (builder.Build (proj), "Build should have succeeded.");
 			}
@@ -156,6 +188,7 @@ public void BuildAotApplicationWithSpecialCharactersInProject (string testName,
 			},
 		};
 
+		// TODO: possibly enable NativeAOT
 		[Test]
 		[TestCaseSource (nameof (AotChecks))]
 		public void BuildAotApplicationWithNdkAndBundleAndÜmläüts (string supportedAbis, bool enableLLVM, bool usesAssemblyBlobs)
@@ -171,6 +204,8 @@ public void BuildAotApplicationWithNdkAndBundleAndÜmläüts (string supportedAb
 				PackageName = "com.xamarin.buildaotappwithspecialchars",
 			};
 
+			// Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
 			proj.SetProperty ("AndroidNdkDirectory", AndroidNdkPath);
 			proj.SetRuntimeIdentifiers (supportedAbis.Split (';'));
 			proj.SetProperty ("EnableLLVM", enableLLVM.ToString ());
@@ -227,6 +262,9 @@ public void BuildAotApplicationAndÜmläüts (string supportedAbis, bool enableL
 				AotAssemblies = true,
 				PackageName = "com.xamarin.buildaotappandbundlewithspecialchars",
 			};
+
+			// Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
 			proj.SetRuntimeIdentifiers (supportedAbis.Split (';'));
 			proj.SetProperty ("EnableLLVM", enableLLVM.ToString ());
 			proj.SetProperty ("AndroidUseAssemblyStore", usesAssemblyBlobs.ToString ());
@@ -353,6 +391,10 @@ public void NoSymbolsArgShouldReduceAppSize ([Values (false, true)] bool skipDeb
 				IsRelease = true,
 				AotAssemblies = true,
 			};
+
+			// Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
+
 			var supportedAbi = "arm64-v8a";
 			proj.SetAndroidSupportedAbis (supportedAbi);
 			proj.SetProperty ("EnableLLVM", true.ToString ());
@@ -393,6 +435,8 @@ public void AotAssembliesInIDE ()
 				IsRelease = true,
 				AotAssemblies = true,
 			};
+			// Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
 			proj.SetAndroidSupportedAbis (supportedAbis);
 			using var b = CreateApkBuilder ();
 			Assert.IsTrue (b.RunTarget (proj, target: "Build"));
@@ -423,6 +467,8 @@ public void CheckWhetherLibcAndLibmAreReferencedInAOTLibraries ()
 				EmbedAssembliesIntoApk = true,
 				AotAssemblies = true,
 			};
+			// Mono-only test
+			proj.SetRuntime (AndroidRuntime.MonoVM);
 			proj.SetProperty ("EnableLLVM", "True");
 
 			var abis = new [] { "arm64-v8a", "x86_64" };