[ObjCRuntime] Enable nullability and clean up Blocks.

src/ImageIO/CGImageMetadata.cs

@@ -143,6 +143,8 @@ static byte TagEnumerator (IntPtr block, NativeHandle key, NativeHandle value)
 			var nsKey = Runtime.GetNSObject<NSString> (key, false)!;
 			var nsValue = Runtime.GetINativeObject<CGImageMetadataTag> (value, false)!;
 			var del = BlockLiteral.GetTarget<CGImageMetadataTagBlock> (block);
+			if (del is null)
+				return default;
 			return del (nsKey, nsValue) ? (byte) 1 : (byte) 0;
 		}
 

src/Metal/MTLDevice.cs

@@ -113,8 +113,7 @@ public static IMTLDevice [] GetAllDevices (MTLDeviceNotificationHandler handler,
 		[UnmanagedCallersOnly]
 		public static unsafe void TrampolineNotificationHandler (IntPtr block, IntPtr device, IntPtr notifyName)
 		{
-			var descriptor = (BlockLiteral*) block;
-			var del = (MTLDeviceNotificationHandler) (descriptor->Target);
+			var del = BlockLiteral.GetTarget<MTLDeviceNotificationHandler> (block);
 			if (del is not null)
 				del ((IMTLDevice) Runtime.GetNSObject (device)!, (Foundation.NSString) Runtime.GetNSObject (notifyName)!);
 		}

src/MetalPerformanceShaders/MPSImageBatch.cs

@@ -88,7 +88,7 @@ public static nuint GetResourceSize (NSArray<MPSImage> imageBatch)
 		[UnmanagedCallersOnly]
 		static unsafe nint InvokeIterator (IntPtr block, IntPtr image, nuint index)
 		{
-			var del = (MPSImageBatchIterator) BlockLiteral.GetTarget<MPSImageBatchIterator> (block);
+			var del = BlockLiteral.GetTarget<MPSImageBatchIterator> (block);
 			if (del is not null) {
 				using var img = Runtime.GetNSObject<MPSImage> (image)!;
 				return del (img, index);

src/Security/SecSharedCredential.cs

@@ -26,8 +26,7 @@ static internal class ActionTrampoline {
 			[UnmanagedCallersOnly]
 			internal static unsafe void Invoke (IntPtr block, IntPtr obj)
 			{
-				var descriptor = (BlockLiteral*) block;
-				var del = (global::System.Action<NSError?>) (descriptor->Target);
+				var del = BlockLiteral.GetTarget<Action<NSError?>> (block);
 				if (del is not null) {
 					del (Runtime.GetNSObject<NSError> (obj));
 				}
@@ -89,8 +88,7 @@ static internal class ArrayErrorActionTrampoline {
 			[UnmanagedCallersOnly]
 			internal static unsafe void Invoke (IntPtr block, IntPtr array, IntPtr err)
 			{
-				var descriptor = (BlockLiteral*) block;
-				var del = (global::System.Action<NSArray?, NSError?>) (descriptor->Target);
+				var del = BlockLiteral.GetTarget<Action<NSArray?, NSError?>> (block);
 				if (del is not null)
 					del (Runtime.GetNSObject<NSArray> (array), Runtime.GetNSObject<NSError> (err));
 			}

src/UIKit/UIAccessibility.cs

@@ -261,8 +261,7 @@ public static Task<bool> RequestGuidedAccessSessionAsync (bool enable)
 		[UnmanagedCallersOnly]
 		static unsafe void TrampolineRequestGuidedAccessSession (IntPtr block, byte enable)
 		{
-			var descriptor = (BlockLiteral*) block;
-			var del = (Action<bool>) (descriptor->Target);
+			var del = BlockLiteral.GetTarget<Action<bool>> (block);
 			if (del is not null)
 				del (enable != 0);
 		}

src/UIKit/UICellAccessory.cs

@@ -64,8 +64,9 @@ static internal class SDUICellAccessoryPosition {
 		[UnmanagedCallersOnly]
 		static unsafe nuint Invoke (IntPtr block, IntPtr accessories)
 		{
-			var descriptor = (BlockLiteral*) block;
-			var del = (UICellAccessoryPosition) (descriptor->Target);
+			var del = BlockLiteral.GetTarget<UICellAccessoryPosition> (block);
+			if (del is null)
+				return default;
 			nuint retval = del (NSArray.ArrayFromHandle<UICellAccessory> (accessories));
 			return retval;
 		}

src/UIKit/UIConfigurationColorTransformer.cs

@@ -43,8 +43,7 @@ static internal class SDUIConfigurationColorTransformerHandler {
 		[UnmanagedCallersOnly]
 		static unsafe IntPtr Invoke (IntPtr block, IntPtr color)
 		{
-			var descriptor = (BlockLiteral*) block;
-			var del = (UIConfigurationColorTransformerHandler) (descriptor->Target);
+			var del = BlockLiteral.GetTarget<UIConfigurationColorTransformerHandler> (block);
 			var retval = del is null ? null : del (Runtime.GetNSObject<UIColor> (color)!);
 			return Runtime.RetainAndAutoreleaseNSObject (retval);
 		}

src/UIKit/UIGuidedAccessRestriction.cs

@@ -50,8 +50,7 @@ static internal class UIGuidedAccessConfigureAccessibilityFeaturesTrampoline {
 			[UnmanagedCallersOnlyAttribute]
 			internal static unsafe void Invoke (IntPtr block, byte success, IntPtr error)
 			{
-				var descriptor = (BlockLiteral*) block;
-				var del = (UIGuidedAccessConfigureAccessibilityFeaturesCompletionHandler) (descriptor->Target);
+				var del = BlockLiteral.GetTarget<UIGuidedAccessConfigureAccessibilityFeaturesCompletionHandler> (block);
 				if (del is not null)
 					del (success != 0, Runtime.GetNSObject<NSError> (error));
 			}

src/bgen/Generator.cs

@@ -1620,6 +1620,10 @@ void GenerateTrampolinesForQueue (TrampolineInfo [] queue)
 				}
 				print ("}");
 			} else {
+				print ("if (del is null)");
+				indent++;
+				print ("return default;");
+				indent--;
 				if (ti.Convert.Length > 0)
 					print (ti.Convert);
 				print ("var retval = del ({1});", ti.DelegateReturnType, ti.Invoke);

tests/cecil-tests/Documentation.KnownFailures.txt

@@ -15214,7 +15214,6 @@ M:ObjCRuntime.AssemblyRegistrationEventArgs.#ctor
 M:ObjCRuntime.BaseWrapper.#ctor(ObjCRuntime.NativeHandle,System.Boolean)
 M:ObjCRuntime.BaseWrapper.Release
 M:ObjCRuntime.BaseWrapper.Retain
-M:ObjCRuntime.BlockLiteral.Dispose
 M:ObjCRuntime.Class.#ctor(ObjCRuntime.NativeHandle)
 M:ObjCRuntime.Class.Equals(ObjCRuntime.Class)
 M:ObjCRuntime.Class.Equals(System.Object)