[ObjCRuntime] Add a DynamicRegistrarSupported property, and use it in a few places that require the dynamic registrar.

docs/website/mmp-errors.md

@@ -375,3 +375,11 @@ This indicates a bug in Xamarin.Mac. Please file a bug at [https://bugzilla.xama
 A potential workaround would be to disable the `register-protocols`
 optimization, by passing `--optimize:-register-protocols` as an additional mmp
 argument in the project's Mac Build options.
+
+### <a name="MM8026"/>MM8026: * is not supported when the dynamic registrar has been linked away.
+
+This usually indicates a bug in Xamarin.Mac, because the dynamic registrar should not be linked away if it's needed. Please file a bug at [https://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS).
+
+It's possible to force the linker to keep the dynamic registrar by adding
+`--optimize=-remove-dynamic-registrar` to the additional mmp arguments in
+the project's Mac Build options.

docs/website/mtouch-errors.md

@@ -2384,3 +2384,11 @@ This indicates a bug in Xamarin.iOS. Please file a bug at [https://bugzilla.xama
 A potential workaround would be to disable the `register-protocols`
 optimization, by passing `--optimize:-register-protocols` as an additional
 mtouch argument in the project's iOS Build options.
+
+### <a name="MT8026"/>MT8026: * is not supported when the dynamic registrar has been linked away.
+
+This usually indicates a bug in Xamarin.iOS, because the dynamic registrar should not be linked away if it's needed. Please file a bug at [https://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS).
+
+It's possible to force the linker to keep the dynamic registrar by adding
+`--optimize=-remove-dynamic-registrar` to the additional mtouch arguments in
+the project's iOS Build options.

src/Foundation/NSObject2.cs

@@ -316,6 +316,9 @@ namespace Foundation {
 			if (does)
 				return true;
 			
+			if (!Runtime.DynamicRegistrationSupported)
+				return false;
+
 			object [] adoptedProtocols = GetType ().GetCustomAttributes (typeof (AdoptsAttribute), true);
 			foreach (AdoptsAttribute adopts in adoptedProtocols){
 				if (adopts.ProtocolHandle == protocol)

src/ObjCRuntime/Blocks.cs

@@ -85,6 +85,9 @@ namespace ObjCRuntime {
 
 		void SetupBlock (Delegate trampoline, Delegate userDelegate, bool safe)
 		{
+			if (!Runtime.DynamicRegistrationSupported)
+				throw ErrorHelper.CreateError (8026, "BlockLiteral.SetupBlock is not supported when the dynamic registrar has been linked away.");
+
 			// We need to get the signature of the target method, so that we can compute
 			// the ObjC signature correctly (the generated method that's actually
 			// invoked by native code does not have enough type information to compute
@@ -275,7 +278,11 @@ namespace ObjCRuntime {
 			// with the proper reference count.
 			BlockLiteral block = new BlockLiteral ();
 			if (signature == null) {
-				block.SetupBlock ((Delegate) handlerDelegate, (Delegate) @delegate);
+				if (Runtime.DynamicRegistrationSupported) {
+					block.SetupBlock ((Delegate) handlerDelegate, (Delegate) @delegate);
+				} else {
+					throw ErrorHelper.CreateError (8026, $"BlockLiteral.GetBlockForDelegate with a null signature is not supported when the dynamic registrar has been linked away (delegate type: {@delegate.GetType ().FullName}).");
+				}
 			} else {
 				block.SetupBlockImpl ((Delegate) handlerDelegate, (Delegate) @delegate, true, signature);
 			}

src/ObjCRuntime/Class.cs

@@ -36,6 +36,9 @@ namespace ObjCRuntime {
 			if (map == null)
 				return;
 
+			if (!Runtime.DynamicRegistrationSupported)
+				return; // Only the dynamic registrar needs the list of registered assemblies.
+			
 			for (int i = 0; i < map->assembly_count; i++) {
 				var ptr = Marshal.ReadIntPtr (map->assembly, i * IntPtr.Size);
 				Runtime.Registrar.SetAssemblyRegistered (Marshal.PtrToStringAuto (ptr));
@@ -116,6 +119,8 @@ namespace ObjCRuntime {
 			}
 
 			if (@class == IntPtr.Zero) {
+				if (!Runtime.DynamicRegistrationSupported)
+					throw ErrorHelper.CreateError (8026, $"Can't register the class {type.FullName} when the dynamic registrar has been linked away.");
 				@class = Register (type);
 				lock (type_to_class)
 					type_to_class [type] = @class;

src/ObjCRuntime/Runtime.cs

@@ -162,6 +162,14 @@ namespace ObjCRuntime {
 
 		internal static unsafe InitializationOptions* options;
 
+		[BindingImpl (BindingImplOptions.Optimizable)]
+		public static bool DynamicRegistrationSupported {
+			get {
+				// The linker may turn calls to this property into a constant
+				return true;
+			}
+		}
+
 		internal static bool Initialized {
 			get { return initialized; }
 		}
@@ -234,7 +242,8 @@ namespace ObjCRuntime {
 
 			NSObjectClass = NSObject.Initialize ();
 
-			Registrar = new DynamicRegistrar ();
+			if (DynamicRegistrationSupported)
+				Registrar = new DynamicRegistrar ();
 			RegisterDelegates (options);
 			Class.Initialize (options);
 			InitializePlatform (options);
@@ -538,6 +547,8 @@ namespace ObjCRuntime {
 			if (a == null)
 				throw new ArgumentNullException ("a");
 
+			if (!DynamicRegistrationSupported)
+				throw ErrorHelper.CreateError (8026, "Runtime.RegisterAssembly is not supported when the dynamic registrar has been linked away.");
 #if MONOMAC
 			var attributes = a.GetCustomAttributes (typeof (RequiredFrameworkAttribute), false);
 
@@ -1410,6 +1421,9 @@ namespace ObjCRuntime {
 			if (export == null)
 				throw new ArgumentNullException ("export");
 
+			if (!DynamicRegistrationSupported)
+				throw ErrorHelper.CreateError (8026, "Runtime.ConnectMethod is not supported when the dynamic registrar has been linked away.");
+
 			Registrar.RegisterMethod (type, method, export);
 		}