[runtime] Call mono_unhandled_exception to raise AppDomain.UnhandledE…

…xception. (#20656)

Call mono_unhandled_exception to raise AppDomain.UnhandledException when
managed exceptions are unhandled.

Partial fix for #15252 (for MonoVM, still pending for CoreCLR, which
needs dotnet/runtime#102730 fixed first).

runtime/coreclr-bridge.m

@@ -1174,4 +1174,11 @@
 	return rv;
 }
 
+void
+xamarin_bridge_raise_unhandled_exception_event (GCHandle exception_gchandle)
+{
+	// There's no way to raise the AppDomain.UnhandledException event.
+	// https://github.com/dotnet/runtime/issues/102730
+}
+
 #endif // CORECLR_RUNTIME

runtime/exports.t4

@@ -169,6 +169,12 @@
 			XamarinRuntime = RuntimeMode.MonoVM,
 		},
 
+		new Export ("void", "mono_unhandled_exception",
+			"MonoObject *", "ex"
+		) {
+			XamarinRuntime = RuntimeMode.MonoVM,
+		},
+
 		new Export ("char*", "mono_array_addr_with_size",
 			"MonoArray *", "array",
 			"int", "size",

runtime/monovm-bridge.m

@@ -563,4 +563,11 @@
 	mono_profiler_install_gc (gc_event_callback, NULL);
 }
 
+void
+xamarin_bridge_raise_unhandled_exception_event (GCHandle exception_gchandle)
+{
+	MonoObject *exc = xamarin_gchandle_get_target (exception_gchandle);
+	mono_unhandled_exception (exc);
+}
+
 #endif // !CORECLR_RUNTIME

runtime/runtime.m

@@ -1143,6 +1143,16 @@ -(void) xamarinSetFlags: (enum XamarinGCHandleFlags) flags;
 	// COOP: We won't get here in coop-mode, because we don't set the uncaught objc exception handler in that case.
 	LOG (PRODUCT ": Received unhandled ObjectiveC exception: %@ %@", [exc name], [exc reason]);
 
+	XamarinGCHandle* exc_handle = [[exc userInfo] objectForKey: @"XamarinManagedExceptionHandle"];
+	if (exc_handle != NULL) {
+		GCHandle exception_gchandle = [exc_handle getHandle];
+		if (exception_gchandle != INVALID_GCHANDLE) {
+			xamarin_bridge_raise_unhandled_exception_event (exception_gchandle);
+			PRINT ("Received unhandled Objective-C exception that was marshalled from a managed exception: %@", exc);
+			abort ();
+		}
+	}
+
 	if (xamarin_handling_unhandled_exceptions == 1) {
 		PRINT ("Detected recursion when handling uncaught Objective-C exception: %@", exc);
 		abort ();

runtime/xamarin/runtime.h

@@ -223,6 +223,7 @@ void			xamarin_bridge_call_runtime_initialize (struct InitializationOptions* opt
 void			xamarin_bridge_register_product_assembly (GCHandle* exception_gchandle);
 MonoMethod *	xamarin_bridge_get_mono_method (MonoReflectionMethod *method);
 void			xamarin_bridge_free_mono_signature (MonoMethodSignature **signature);
+void			xamarin_bridge_raise_unhandled_exception_event (GCHandle exception_gchandle); // the GCHandle is *not* freed. This method will return after raising the event.
 bool			xamarin_register_monoassembly (MonoAssembly *assembly, GCHandle *exception_gchandle);
 void			xamarin_install_nsautoreleasepool_hooks ();
 void			xamarin_enable_new_refcount ();

tests/dotnet/ExceptionalTestApp/AppDelegate.cs

@@ -0,0 +1,44 @@
+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
+
+			var testCaseString = Environment.GetEnvironmentVariable ("EXCEPTIONAL_TEST_CASE");
+			if (string.IsNullOrEmpty (testCaseString)) {
+				Console.WriteLine ($"The environment variable EXCEPTIONAL_TEST_CASE wasn't set.");
+				return 2;
+			}
+			var testCase = int.Parse (testCaseString);
+			switch (testCase) {
+			case 1:
+				AppDomain.CurrentDomain.UnhandledException += (object sender, UnhandledExceptionEventArgs e) => {
+					if (e.ExceptionObject is TestCaseException) {
+						Console.WriteLine (Environment.GetEnvironmentVariable ("MAGIC_WORD"));
+					} else {
+						Console.WriteLine ($"Unexpected exception type: {e.ExceptionObject?.GetType ()}");
+					}
+					Environment.Exit (0);
+				};
+				throw new TestCaseException ();
+			default:
+				Console.WriteLine ($"Unknown test case: {testCase}");
+				return 3;
+			}
+
+			return 1;
+		}
+	}
+}
+
+class TestCaseException : Exception {
+	public TestCaseException ()
+		: base ("Testing, testing")
+	{
+	}
+}

tests/dotnet/ExceptionalTestApp/MacCatalyst/ExceptionalTestApp.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/ExceptionalTestApp/MacCatalyst/Makefile

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

tests/dotnet/ExceptionalTestApp/Makefile

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

tests/dotnet/ExceptionalTestApp/iOS/ExceptionalTestApp.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/ExceptionalTestApp/iOS/Makefile

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

tests/dotnet/ExceptionalTestApp/macOS/ExceptionalTestApp.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/ExceptionalTestApp/macOS/Makefile

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

tests/dotnet/ExceptionalTestApp/shared.csproj

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+	<PropertyGroup>
+		<OutputType>Exe</OutputType>
+
+		<ApplicationTitle>ExceptionalTestApp</ApplicationTitle>
+		<ApplicationId>com.xamarin.exceptionaltestapp</ApplicationId>
+	</PropertyGroup>
+
+	<Import Project="../../common/shared-dotnet.csproj" />
+
+	<ItemGroup>
+		<Compile Include="../*.cs" />
+	</ItemGroup>
+</Project>

tests/dotnet/ExceptionalTestApp/shared.mk

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

tests/dotnet/ExceptionalTestApp/tvOS/ExceptionalTestApp.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/ExceptionalTestApp/tvOS/Makefile

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

tests/dotnet/UnitTests/ProjectTest.cs

@@ -1764,5 +1764,31 @@ public void SourcelinkTest (ApplePlatform platform, string runtimeIdentifiers, s
 
 			Assert.AreEqual ($"sourcelink test passed: {pdbFile}", test.StandardOutput.ToString ().TrimEnd ('\n'));
 		}
+
+
+		[Test]
+		// [TestCase (ApplePlatform.iOS)] // Skipping because we're not executing tvOS apps anyway (but it should work)
+		// [TestCase (ApplePlatform.TVOS)] // Skipping because we're not executing tvOS apps anyway (but it should work)
+		[TestCase (ApplePlatform.MacOSX)] // https://github.com/dotnet/runtime/issues/102730
+		[TestCase (ApplePlatform.MacCatalyst)]
+		public void RaisesAppDomainUnhandledExceptionEvent (ApplePlatform platform)
+		{
+			var project = "ExceptionalTestApp";
+			Configuration.IgnoreIfIgnoredPlatform (platform);
+
+			var runtimeIdentifiers = GetDefaultRuntimeIdentifier (platform);
+			var project_path = GetProjectPath (project, runtimeIdentifiers: runtimeIdentifiers, platform: platform, out var appPath);
+			Clean (project_path);
+			var properties = GetDefaultProperties ();
+			DotNet.AssertBuild (project_path, properties);
+
+			if (CanExecute (platform, runtimeIdentifiers)) {
+				var env = new Dictionary<string, string?> {
+					{ "EXCEPTIONAL_TEST_CASE", "1" },
+				};
+				var appExecutable = GetNativeExecutable (platform, appPath);
+				var output = ExecuteWithMagicWordAndAssert (appExecutable, env);
+			}
+		}
 	}
 }

tests/dotnet/UnitTests/TestBaseClass.cs

@@ -327,28 +327,28 @@ protected string GenerateProject (ApplePlatform platform, string name, string ru
 			return csproj;
 		}
 
-		protected string ExecuteWithMagicWordAndAssert (ApplePlatform platform, string runtimeIdentifiers, string executable)
+		protected string ExecuteWithMagicWordAndAssert (ApplePlatform platform, string runtimeIdentifiers, string executable, Dictionary<string, string?>? environment = null)
 		{
 			if (!CanExecute (platform, runtimeIdentifiers))
 				return string.Empty;
 
-			return ExecuteWithMagicWordAndAssert (executable);
+			return ExecuteWithMagicWordAndAssert (executable, environment);
 		}
 
-		protected string ExecuteWithMagicWordAndAssert (string executable)
+		protected string ExecuteWithMagicWordAndAssert (string executable, Dictionary<string, string?>? environment = null)
 		{
 			if (Environment.OSVersion.Platform == PlatformID.Win32NT) {
 				Console.WriteLine ($"Not executing '{executable}' because we're on Windows.");
 				return string.Empty;
 			}
 
-			var rv = Execute (executable, out var output, out string magicWord);
+			var rv = Execute (executable, out var output, out string magicWord, environment);
 			Assert.That (output.ToString (), Does.Contain (magicWord), "Contains magic word");
 			Assert.AreEqual (0, rv.ExitCode, "ExitCode");
 			return output.ToString ();
 		}
 
-		protected Execution Execute (string executable, out StringBuilder output, out string magicWord)
+		protected Execution Execute (string executable, out StringBuilder output, out string magicWord, Dictionary<string, string?>? environment = null)
 		{
 			if (!File.Exists (executable))
 				throw new FileNotFoundException ($"The executable '{executable}' does not exists.");
@@ -358,6 +358,10 @@ protected Execution Execute (string executable, out StringBuilder output, out st
 				{ "MAGIC_WORD", magicWord },
 				{ "DYLD_FALLBACK_LIBRARY_PATH", null }, // VSMac might set this, which may cause tests to crash.
 			};
+			if (environment is not null) {
+				foreach (var kvp in environment)
+					env [kvp.Key] = kvp.Value;
+			}
 
 			output = new StringBuilder ();
 			return Execution.RunWithStringBuildersAsync (executable, Array.Empty<string> (), environment: env, standardOutput: output, standardError: output, timeout: TimeSpan.FromSeconds (15)).Result;