[dotnet] Fix support for startup hooks. Fixes #24492.

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -124,7 +124,6 @@
 		<InvariantGlobalization Condition="'$(InvariantGlobalization)' == ''">false</InvariantGlobalization>
 		<!-- Enable HybridGlobalization by default-->
 		<HybridGlobalization Condition="'$(InvariantGlobalization)' != 'true'">true</HybridGlobalization>
-		<StartupHookSupport Condition="'$(StartupHookSupport)' == ''">false</StartupHookSupport>
 		<UseSizeOptimizedLinq Condition="'$(UseSizeOptimizedLinq)' == ''">true</UseSizeOptimizedLinq>
 		<UseSystemResourceKeys Condition="'$(UseSystemResourceKeys)' == '' And '$(_BundlerDebug)' != 'true'">true</UseSystemResourceKeys>
 		<UseSystemResourceKeys Condition="'$(UseSystemResourceKeys)' == '' And '$(_BundlerDebug)' == 'true'">false</UseSystemResourceKeys>
@@ -142,6 +141,12 @@
 		<DynamicCodeSupport Condition="'$(DynamicCodeSupport)' == '' And ( '$(MtouchInterpreter)' == '' And '$(UseInterpreter)' != 'true' ) And ('$(_PlatformName)' == 'iOS' Or '$(_PlatformName)' == 'tvOS' Or '$(_PlatformName)' == 'MacCatalyst')">false</DynamicCodeSupport>
 		<_ComObjectDescriptorSupport Condition="'$(_ComObjectDescriptorSupport)' == ''">false</_ComObjectDescriptorSupport>
 
+		<!-- StartupHookSupport is used for Hot Reload, so we enable it unless the Optimize flag is set. -->
+		<!-- When we set StartupHookSupport=true ourselves, suppress the resulting trimmer warning (but not if the developer set it). -->
+		<_SuppressStartupHookSupportTrimWarning Condition="'$(StartupHookSupport)' == '' And '$(Optimize)' != 'true'">true</_SuppressStartupHookSupportTrimWarning>
+		<StartupHookSupport Condition="'$(StartupHookSupport)' == '' And '$(Optimize)' != 'true'">true</StartupHookSupport>
+		<StartupHookSupport Condition="'$(StartupHookSupport)' == ''">false</StartupHookSupport>
+
 		<!-- We don't need to generate reference assemblies for apps or app extensions -->
 		<ProduceReferenceAssembly Condition="'$(ProduceReferenceAssembly)' == '' And ('$(OutputType)' == 'Exe' Or '$(IsAppExtension)' == 'true')">false</ProduceReferenceAssembly>
 
@@ -694,6 +699,7 @@
 
 		<ItemGroup>
 			<!-- Configure linker features -->
+			<RuntimeHostConfigurationOption Include="ObjCRuntime.SuppressStartupHookTrimWarning" Value="true" Trim="true" Condition="'$(_SuppressStartupHookSupportTrimWarning)' == 'true'" />
 			<RuntimeHostConfigurationOption Include="ObjCRuntime.AggressiveAttributeTrimming" Value="true" Trim="true" Condition="'$(MobileAggressiveAttributeTrimming)' == 'true'" />
 			<RuntimeHostConfigurationOption Include="ObjCRuntime.AggressiveAttributeTrimmingMono" Value="true" Trim="true" Condition="'$(MobileAggressiveAttributeTrimming)' == 'true' And '$(_XamarinRuntime)' == 'MonoVM'" />
 			<RuntimeHostConfigurationOption Include="ObjCRUntime.AggressiveAttributeTrimmingOnlyWithStaticRegistrar" value="true" Trim="true" Condition="'$(MobileAggressiveAttributeTrimming)' == 'true' And ('$(Registrar)' == 'static' Or '$(Registrar)' == 'managed-static')" />
@@ -1266,6 +1272,7 @@
 			<_RuntimeConfigReservedProperties Include="NATIVE_DLL_SEARCH_DIRECTORIES" />
 			<_RuntimeConfigReservedProperties Include="RUNTIME_IDENTIFIER" />
 			<_RuntimeConfigReservedProperties Include="APP_CONTEXT_BASE_DIRECTORY" />
+			<_RuntimeConfigReservedProperties Include="STARTUP_HOOKS" />
 		</ItemGroup>
 		<RuntimeConfigParserTask
 			Condition="'$(GenerateRuntimeConfigurationFiles)' == 'true'"

runtime/runtime.m

@@ -2406,6 +2406,7 @@ -(struct NSObjectData*) xamarinGetNSObjectData;
 	char *pinvokeOverride = xamarin_strdup_printf ("%p", &xamarin_pinvoke_override);
 	char *trusted_platform_assemblies = xamarin_compute_trusted_platform_assemblies ();
 	char *native_dll_search_directories = xamarin_compute_native_dll_search_directories ();
+	const char *startupHooks = getenv ("DOTNET_STARTUP_HOOKS");
 
 	// All the properties we pass here must also be listed in the _RuntimeConfigReservedProperties item group
 	// for the _CreateRuntimeConfiguration target in dotnet/targets/Xamarin.Shared.Sdk.targets.
@@ -2416,6 +2417,7 @@ -(struct NSObjectData*) xamarinGetNSObjectData;
 		"TRUSTED_PLATFORM_ASSEMBLIES",
 		"NATIVE_DLL_SEARCH_DIRECTORIES",
 		"RUNTIME_IDENTIFIER",
+		"STARTUP_HOOKS", // must be last entry (because we just decrement propertyCount to not pass it if it's not set)
 	};
 	const char *propertyValues[] = {
 		xamarin_get_bundle_path (),
@@ -2424,10 +2426,14 @@ -(struct NSObjectData*) xamarinGetNSObjectData;
 		trusted_platform_assemblies,
 		native_dll_search_directories,
 		RUNTIMEIDENTIFIER,
+		startupHooks,
 	};
 	static_assert (sizeof (propertyKeys) == sizeof (propertyValues), "The number of keys and values must be the same.");
 
 	int propertyCount = (int) (sizeof (propertyValues) / sizeof (propertyValues [0]));
+	if (startupHooks == NULL || startupHooks [0] == 0)
+		propertyCount--;
+
 	bool rv = xamarin_bridge_vm_initialize (propertyCount, propertyKeys, propertyValues);
 
 	xamarin_free (pinvokeOverride);

src/TrimAttributes.LinkDescription.xml

@@ -290,4 +290,15 @@
       </attribute>
     </type>
   </assembly>
+  <!-- Suppress the IL2026 warning from System.StartupHookProvider.ProcessStartupHooks when we're the ones enabling StartupHookSupport -->
+  <assembly fullname="System.Private.CoreLib" feature="ObjCRuntime.SuppressStartupHookTrimWarning" featurevalue="true">
+    <type fullname="System.StartupHookProvider">
+      <method name="ProcessStartupHooks">
+        <attribute fullname="System.Diagnostics.CodeAnalysis.UnconditionalSuppressMessageAttribute">
+          <argument>ILLink</argument>
+          <argument>IL2026</argument>
+        </attribute>
+      </method>
+    </type>
+  </assembly>
 </linker>

tests/dotnet/StartupHookLibrary/MacCatalyst/StartupHookLibrary.csproj

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-maccatalyst</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>
+

tests/dotnet/StartupHookLibrary/StartupHook.cs

@@ -0,0 +1,17 @@
+using System;
+
+using Foundation;
+
+
+class StartupHook {
+	public static void Initialize ()
+	{
+		Console.WriteLine ("STARTUP");
+
+		StartupStatus.Initialized = true;
+	}
+}
+
+public static class StartupStatus {
+	public static bool Initialized { get; internal set; }
+}

tests/dotnet/StartupHookLibrary/iOS/StartupHookLibrary.csproj

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-ios</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>
+

tests/dotnet/StartupHookLibrary/macOS/StartupHookLibrary.csproj

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-macos</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>
+

tests/dotnet/StartupHookLibrary/shared.csproj

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+	<ItemGroup>
+		<Compile Include="../*.cs" />
+	</ItemGroup>
+</Project>

tests/dotnet/StartupHookLibrary/tvOS/StartupHookLibrary.csproj

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-tvos</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>
+

tests/dotnet/StartupHookTest/AppDelegate.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Runtime.InteropServices;
+
+using Foundation;
+
+namespace MySimpleApp {
+	public class Program {
+		static int Main (string [] args)
+		{
+			GC.KeepAlive (typeof (NSObject)); // prevent linking away the platform assembly
+
+			Console.WriteLine (Environment.GetEnvironmentVariable ("MAGIC_WORD"));
+			Console.WriteLine ($"Startup.Initialized: {StartupHook.Initialized}");
+			Console.WriteLine ($"StartupStatus.Initialized: {StartupStatus.Initialized}");
+
+			var rv = 0;
+
+			if (!StartupHook.Initialized)
+				rv += 1;
+
+			if (!StartupStatus.Initialized)
+				rv += 2;
+
+			return rv;
+		}
+	}
+}
+
+class StartupHook {
+	public static bool Initialized { get; private set; }
+	public static void Initialize ()
+	{
+		Initialized = true;
+	}
+}

tests/dotnet/StartupHookTest/MacCatalyst/Makefile

@@ -0,0 +1 @@
+include ../shared.mk

tests/dotnet/StartupHookTest/MacCatalyst/StartupHookTest.csproj

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-maccatalyst</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>

tests/dotnet/StartupHookTest/Makefile

@@ -0,0 +1,2 @@
+TOP=../../..
+include $(TOP)/tests/common/shared-dotnet-test.mk

tests/dotnet/StartupHookTest/iOS/Makefile

@@ -0,0 +1 @@
+include ../shared.mk

tests/dotnet/StartupHookTest/iOS/StartupHookTest.csproj

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-ios</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>

tests/dotnet/StartupHookTest/macOS/Makefile

@@ -0,0 +1 @@
+include ../shared.mk

tests/dotnet/StartupHookTest/macOS/StartupHookTest.csproj

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-macos</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>

tests/dotnet/StartupHookTest/shared.csproj

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+	<PropertyGroup>
+		<OutputType>Exe</OutputType>
+
+		<ApplicationTitle>StartupHookTest</ApplicationTitle>
+		<ApplicationId>com.xamarin.startuphooktest</ApplicationId>
+	</PropertyGroup>
+
+	<Import Project="../../common/shared-dotnet.csproj" />
+
+	<ItemGroup>
+		<Compile Include="../*.cs" />
+
+		<ProjectReference Include="../../StartupHookLibrary/$(_PlatformName)/StartupHookLibrary.csproj" />
+	</ItemGroup>
+</Project>

tests/dotnet/StartupHookTest/shared.mk

@@ -0,0 +1,3 @@
+TOP=../../../..
+TESTNAME=StartupHookTest
+include $(TOP)/tests/common/shared-dotnet.mk

tests/dotnet/StartupHookTest/tvOS/Makefile

@@ -0,0 +1 @@
+include ../shared.mk

tests/dotnet/StartupHookTest/tvOS/StartupHookTest.csproj

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+	<PropertyGroup>
+		<TargetFramework>net$(BundledNETCoreAppTargetFrameworkVersion)-tvos</TargetFramework>
+	</PropertyGroup>
+	<Import Project="..\shared.csproj" />
+</Project>

tests/dotnet/UnitTests/StartupHookTest.cs

@@ -0,0 +1,114 @@
+#nullable enable
+
+namespace Xamarin.Tests {
+	[TestFixture]
+	public class StartupHookTest : TestBaseClass {
+		const string project = "StartupHookTest";
+
+		[TestCase (ApplePlatform.MacOSX, "osx-arm64")]
+		[TestCase (ApplePlatform.MacCatalyst, "maccatalyst-x64")]
+		public void EnabledForDebug (ApplePlatform platform, string runtimeIdentifiers)
+		{
+			Configuration.IgnoreIfIgnoredPlatform (platform);
+
+			var configuration = "Debug";
+			var project_path = GetProjectPath (project, runtimeIdentifiers: runtimeIdentifiers, platform: platform, out var appPath, configuration: configuration);
+			Clean (project_path);
+
+			var properties = GetDefaultProperties (runtimeIdentifiers);
+			properties ["Configuration"] = configuration;
+			DotNet.AssertBuild (project_path, properties);
+
+			if (CanExecute (platform, properties)) {
+				var appExecutable = GetNativeExecutable (platform, appPath);
+				var env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookTest:StartupHookLibrary" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env);
+
+				env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookLibrary" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 1); // this should fail
+
+				env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookTest" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 2); // this should fail
+			}
+		}
+
+		[TestCase (ApplePlatform.MacOSX, "osx-arm64")]
+		[TestCase (ApplePlatform.MacCatalyst, "maccatalyst-x64")]
+		public void DisabledForRelease (ApplePlatform platform, string runtimeIdentifiers)
+		{
+			Configuration.IgnoreIfIgnoredPlatform (platform);
+
+			var configuration = "Release";
+			var project_path = GetProjectPath (project, runtimeIdentifiers: runtimeIdentifiers, platform: platform, out var appPath, configuration: configuration);
+			Clean (project_path);
+
+			var properties = GetDefaultProperties (runtimeIdentifiers);
+			properties ["Configuration"] = configuration;
+			DotNet.AssertBuild (project_path, properties);
+
+			if (CanExecute (platform, properties)) {
+				var appExecutable = GetNativeExecutable (platform, appPath);
+				var env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookTest:StartupHookLibrary" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 3); // this should fail
+
+				env = new Dictionary<string, string?> ();
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 3); // this should fail
+
+				env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookLibrary" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 3); // this should fail
+
+				env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookTest" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 3); // this should fail
+			}
+		}
+
+		[TestCase (ApplePlatform.MacOSX, "osx-arm64")]
+		[TestCase (ApplePlatform.MacCatalyst, "maccatalyst-x64")]
+		public void Enableable (ApplePlatform platform, string runtimeIdentifiers)
+		{
+			Configuration.IgnoreIfIgnoredPlatform (platform);
+
+			var configuration = "Release";
+			var project_path = GetProjectPath (project, runtimeIdentifiers: runtimeIdentifiers, platform: platform, out var appPath, configuration: configuration);
+			Clean (project_path);
+
+			var properties = GetDefaultProperties (runtimeIdentifiers);
+			properties ["Configuration"] = configuration;
+			properties ["StartupHookSupport"] = "true";
+			DotNet.AssertBuild (project_path, properties);
+
+			if (CanExecute (platform, properties)) {
+				var appExecutable = GetNativeExecutable (platform, appPath);
+				var env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookTest:StartupHookLibrary" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env); // this should work
+
+				env = new Dictionary<string, string?> ();
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 3); // this should fail
+
+				env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookLibrary" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 1); // this should fail
+
+				env = new Dictionary<string, string?> {
+					{ "DOTNET_STARTUP_HOOKS", "StartupHookTest" },
+				};
+				ExecuteWithMagicWordAndAssert (appExecutable, env, expectedExitCode: 2); // this should fail
+			}
+		}
+	}
+}

tests/dotnet/UnitTests/TestBaseClass.cs

@@ -386,7 +386,7 @@ protected string ExecuteWithMagicWordAndAssert (ApplePlatform platform, string r
 			return ExecuteWithMagicWordAndAssert (executable, environment);
 		}
 
-		protected string ExecuteWithMagicWordAndAssert (string executable, Dictionary<string, string?>? environment = null)
+		protected string ExecuteWithMagicWordAndAssert (string executable, Dictionary<string, string?>? environment = null, int expectedExitCode = 0)
 		{
 			if (Environment.OSVersion.Platform == PlatformID.Win32NT) {
 				Console.WriteLine ($"Not executing '{executable}' because we're on Windows.");
@@ -395,8 +395,8 @@ protected string ExecuteWithMagicWordAndAssert (string executable, Dictionary<st
 
 			var rv = Execute (executable, out var output, out string magicWord, environment);
 			var outputString = output.ToString ();
-			if (rv.ExitCode != 0) {
-				var msg = $"'{executable}' exited with exit code {rv.ExitCode} (timed out: {rv.TimedOut} timeout: {rv.Timeout}):" +
+			if (rv.ExitCode != expectedExitCode) {
+				var msg = $"'{executable}' exited with exit code {rv.ExitCode} (expected exit code {expectedExitCode}) (timed out: {rv.TimedOut} timeout: {rv.Timeout}):" +
 							"\t" + outputString.Replace ("\n", "\n\t").TrimEnd (new char [] { '\n', '\t' });
 				Console.WriteLine (msg);
 				Assert.Fail (msg);