[generator] Prototype typed UCO binding callbacks

external/Java.Interop/tests/generator-Tests/Integration-Tests/Compiler.cs

@@ -51,18 +51,7 @@ public static Assembly Compile (Xamarin.Android.Binder.CodeGeneratorOptions opti
 				.ToArray ();
 
 			// Set up the assemblies we need to reference
-			var binDir = Path.GetDirectoryName (typeof (BaseGeneratorTest).Assembly.Location);
-			var facDir = GetFacadesPath ();
-
-			var referencePaths = new[]{
-				unitTestFrameworkAssemblyPath,
-				typeof(object).Assembly.Location,
-				typeof(Enumerable).Assembly.Location,
-				typeof(Uri).Assembly.Location,
-				Path.Combine (binDir, "Java.Interop.dll"),
-				Path.Combine (facDir, "netstandard.dll"),
-				Path.Combine (facDir, "System.Runtime.dll"),
-			};
+			var referencePaths = GetReferencePaths ();
 
 			var references = referencePaths.Select (p => MetadataReference.CreateFromFile (p)).ToArray ();
 
@@ -76,10 +65,43 @@ public static Assembly Compile (Xamarin.Android.Binder.CodeGeneratorOptions opti
 
 			Console.WriteLine ($"# Trying to compile: {testCommandLine}");
 
+			return Compile (Path.GetFileName (assemblyFileName), syntax_trees, references, out hasErrors, out output, allowWarnings);
+		}
+
+		public static Assembly CompileSources (IEnumerable<string> sources, out bool hasErrors, out string output)
+		{
+			var supportFiles = Directory.EnumerateFiles (Path.Combine (Path.GetDirectoryName (supportFilePath), "SupportFiles"),
+				"*.cs", SearchOption.AllDirectories);
+			var parseOptions = new CSharpParseOptions (preprocessorSymbols: new [] { "NET" });
+			var syntaxTrees = sources.Concat (supportFiles.Select (File.ReadAllText))
+				.Select (s => CSharpSyntaxTree.ParseText (s, parseOptions));
+			var references = GetReferencePaths ().Select (p => MetadataReference.CreateFromFile (p));
+
+			return Compile ("GeneratedCallbacks_" + Guid.NewGuid ().ToString ("N"), syntaxTrees, references, out hasErrors, out output, allowWarnings: true);
+		}
+
+		static string [] GetReferencePaths ()
+		{
+			var binDir = Path.GetDirectoryName (typeof (BaseGeneratorTest).Assembly.Location);
+			var facDir = GetFacadesPath ();
+			return new [] {
+				unitTestFrameworkAssemblyPath,
+				typeof (object).Assembly.Location,
+				typeof (Enumerable).Assembly.Location,
+				typeof (Uri).Assembly.Location,
+				Path.Combine (binDir, "Java.Interop.dll"),
+				Path.Combine (facDir, "netstandard.dll"),
+				Path.Combine (facDir, "System.Runtime.dll"),
+			};
+		}
+
+		static Assembly Compile (string assemblyName, IEnumerable<SyntaxTree> syntaxTrees, IEnumerable<MetadataReference> references,
+			out bool hasErrors, out string output, bool allowWarnings)
+		{
 			// Compile!
 			var compilation = CSharpCompilation.Create (
-			    Path.GetFileName (assemblyFileName),
-			    syntaxTrees: syntax_trees,
+			    assemblyName,
+			    syntaxTrees: syntaxTrees,
 			    references: references,
 			    options: new CSharpCompilationOptions (OutputKind.DynamicallyLinkedLibrary, allowUnsafe: true));
 

external/Java.Interop/tools/generator/CodeGenerationOptions.cs

@@ -66,6 +66,17 @@ public      SymbolTable             SymbolTable             {
 		public bool UseObsoletedOSPlatformAttributes { get; set; }
 		public bool UseRestrictToAttributes { get; set; }
 		public bool FixObsoleteOverrides { get; set; }
+
+		// Experimental: emit each supported non-generic `n_*` binding callback as an
+		// [UnmanagedCallersOnly] method which forwards to a shared typed marshaling helper,
+		// and omit the `cb_*` delegate cache field and the `Get*Handler ()` connector method.
+		public bool UseUnmanagedCallersOnlyCallbacks { get; set; }
+
+		// Compact, deterministic names for the callback infrastructure emitted for
+		// UseUnmanagedCallersOnlyCallbacks. Shared so that a [Register] connector and the callback
+		// it names agree even when they are emitted by different source writers.
+		public generator.SourceWriters.CallbackNameAllocator CallbackNames { get; } = new generator.SourceWriters.CallbackNameAllocator ();
+
 		public bool RemoveConstSugar => BuildingCoreAssembly;
 
 		bool? buildingCoreAssembly;

external/Java.Interop/tools/generator/CodeGenerator.cs

@@ -84,6 +84,7 @@ static void Run (CodeGeneratorOptions options, DirectoryAssemblyResolver resolve
 				UseObsoletedOSPlatformAttributes = options.UseObsoletedOSPlatformAttributes,
 				UseRestrictToAttributes = options.UseRestrictToAttributes,
 				FixObsoleteOverrides = options.FixObsoleteOverrides,
+				UseUnmanagedCallersOnlyCallbacks = options.UseUnmanagedCallersOnlyCallbacks,
 			};
 			var resolverCache       = new TypeDefinitionCache ();
 

external/Java.Interop/tools/generator/CodeGeneratorOptions.cs

@@ -56,6 +56,7 @@ public CodeGeneratorOptions ()
 		public bool		    SupportNullableReferenceTypes { get; set; }
 		public bool		    UseRestrictToAttributes { get; set; }
 		public bool		    FixObsoleteOverrides { get; set;} = true;
+		public bool		    UseUnmanagedCallersOnlyCallbacks { get; set; }
 		public bool			UseObsoletedOSPlatformAttributes { get; set; }
 
 		public XmldocStyle		    XmldocStyle { get; set; } = XmldocStyle.IntelliSense;
@@ -109,7 +110,7 @@ public static CodeGeneratorOptions Parse (string[] args)
 					"SDK Platform {VERSION}/API level.",
 					v => opts.ApiLevel = v },
 				{ "lang-features=",
-					"For internal use. (Flags: interface-constants,default-interface-methods,nested-interface-types,nullable-reference-types,obsoleted-platform-attributes,restrict-to-attributes,do-not-fix-obsolete-overrides)",
+					"For internal use. (Flags: interface-constants,default-interface-methods,nested-interface-types,nullable-reference-types,obsoleted-platform-attributes,restrict-to-attributes,do-not-fix-obsolete-overrides,unmanaged-callers-only-callbacks)",
 					v => {
 						opts.SupportInterfaceConstants = v?.Contains ("interface-constants") == true;
 						opts.SupportDefaultInterfaceMethods = v?.Contains ("default-interface-methods") == true;
@@ -118,6 +119,7 @@ public static CodeGeneratorOptions Parse (string[] args)
 						opts.UseObsoletedOSPlatformAttributes = v?.Contains ("obsoleted-platform-attributes") == true;
 						opts.UseRestrictToAttributes = v?.Contains ("restrict-to-attributes") == true;
 						opts.FixObsoleteOverrides = v?.Contains ("do-not-fix-obsolete-overrides") == false;
+						opts.UseUnmanagedCallersOnlyCallbacks = v?.Contains ("unmanaged-callers-only-callbacks") == true;
 						}},
 				{ "preserve-enums",
 					"For internal use.",

external/Java.Interop/tools/generator/Java.Interop.Tools.Generator.ObjectModel/NamespaceMapping.cs

@@ -25,6 +25,14 @@ public void Generate (CodeGenerationOptions opt, GenerationInfo gen_info)
 				sw.WriteLine ();
 
 				if (opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1) {
+					// Only the experimental format is marked: the absence of the attribute means
+					// JavaPeerCallbackFormatAttribute.ConnectorDelegates, so existing bindings and
+					// existing consumers are unaffected.
+					if (opt.UseUnmanagedCallersOnlyCallbacks) {
+						sw.WriteLine ("[assembly:global::Java.Interop.JavaPeerCallbackFormat (global::Java.Interop.JavaPeerCallbackFormatAttribute.UnmanagedCallersOnlyCallbacks)]");
+						sw.WriteLine ();
+					}
+
 					foreach (var p in mappings) {
 						sw.WriteLine ($"[assembly:global::Android.Runtime.NamespaceMapping (Java = \"{p.Key}\", Managed=\"{p.Value}\")]");
 					}

external/Java.Interop/tools/generator/SourceWriters/BoundAbstractProperty.cs

@@ -48,7 +48,7 @@ public BoundAbstractProperty (GenBase gen, Property property, CodeGenerationOpti
 
 			SourceWriterExtensions.AddSupportedOSPlatform (GetterAttributes, property.Getter, opt);
 
-			GetterAttributes.Add (new RegisterAttr (property.Getter.JavaName, property.Getter.JniSignature, property.Getter.GetConnectorNameFull (opt), additionalProperties: property.Getter.AdditionalAttributeString ()) {
+			GetterAttributes.Add (new RegisterAttr (property.Getter.JavaName, property.Getter.JniSignature, UnmanagedCallbackSupport.GetPropertyConnectorNameFull (gen, property, property.Getter, opt), additionalProperties: property.Getter.AdditionalAttributeString ()) {
 				MemberType	    = opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1 ? null : (MemberTypes?) MemberTypes.Method,
 			});
 
@@ -63,7 +63,7 @@ public BoundAbstractProperty (GenBase gen, Property property, CodeGenerationOpti
 				SourceWriterExtensions.AddSupportedOSPlatform (SetterAttributes, property.Setter, opt);
 
 				SourceWriterExtensions.AddMethodCustomAttributes (SetterAttributes, property.Setter);
-				SetterAttributes.Add (new RegisterAttr (property.Setter.JavaName, property.Setter.JniSignature, property.Setter.GetConnectorNameFull (opt), additionalProperties: property.Setter.AdditionalAttributeString ()) {
+				SetterAttributes.Add (new RegisterAttr (property.Setter.JavaName, property.Setter.JniSignature, UnmanagedCallbackSupport.GetPropertyConnectorNameFull (gen, property, property.Setter, opt), additionalProperties: property.Setter.AdditionalAttributeString ()) {
 					MemberType	    = opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1 ? null : (MemberTypes?) MemberTypes.Method,
 				});
 			}

external/Java.Interop/tools/generator/SourceWriters/BoundInterface.cs

@@ -38,6 +38,11 @@ public BoundInterface (InterfaceGen iface, CodeGenerationOptions opt, CodeGenera
 
 			UsePriorityOrder = true;
 
+			// Renaming happens up front, before any member is written, so that every writer -- and
+			// in particular the callback name allocator, which snapshots a type's members the first
+			// time it is asked about one of them -- observes the final managed names.
+			FixupInvokerMethodNames (iface);
+
 			SetVisibility (iface.Visibility);
 
 			iface.JavadocInfo?.AddJavadocs (Comments);
@@ -223,13 +228,20 @@ void AddProperties (InterfaceGen iface, CodeGenerationOptions opt)
 			}
 		}
 
-		void AddMethods (InterfaceGen iface, CodeGenerationOptions opt)
+		// A method whose managed name would collide with the interface itself or with one of its
+		// properties is prefixed with "Invoke".
+		static void FixupInvokerMethodNames (InterfaceGen iface)
 		{
 			foreach (var m in iface.Methods.Where (m => !m.IsStatic && !m.IsInterfaceDefaultMethod)) {
 				if (m.Name == iface.Name || iface.ContainsProperty (m.Name, true))
 					m.Name = "Invoke" + m.Name;
+			}
+		}
 
-				Methods.Add (new BoundInterfaceMethodDeclaration (m, iface.AssemblyQualifiedName + "Invoker", opt));
+		void AddMethods (InterfaceGen iface, CodeGenerationOptions opt)
+		{
+			foreach (var m in iface.Methods.Where (m => !m.IsStatic && !m.IsInterfaceDefaultMethod)) {
+				Methods.Add (new BoundInterfaceMethodDeclaration (iface, m, iface.AssemblyQualifiedName + "Invoker", opt));
 			}
 
 			if (!opt.SupportDefaultInterfaceMethods)

external/Java.Interop/tools/generator/SourceWriters/BoundInterfaceMethodDeclaration.cs

@@ -16,7 +16,7 @@ public class BoundInterfaceMethodDeclaration : MethodWriter
 		readonly Method method;
 		readonly CodeGenerationOptions opt;
 
-		public BoundInterfaceMethodDeclaration (Method method, string adapter, CodeGenerationOptions opt)
+		public BoundInterfaceMethodDeclaration (GenBase iface, Method method, string adapter, CodeGenerationOptions opt)
 		{
 			this.method = method;
 			this.opt = opt;
@@ -44,7 +44,7 @@ public BoundInterfaceMethodDeclaration (Method method, string adapter, CodeGener
 
 			SourceWriterExtensions.AddSupportedOSPlatform (Attributes, method, opt);
 
-			Attributes.Add (new RegisterAttr (method.JavaName, method.JniSignature, method.ConnectorName + ":" + method.GetAdapterName (opt, adapter), additionalProperties: method.AdditionalAttributeString ()) {
+			Attributes.Add (new RegisterAttr (method.JavaName, method.JniSignature, UnmanagedCallbackSupport.GetConnectorName (iface, method, opt) + ":" + method.GetAdapterName (opt, adapter), additionalProperties: method.AdditionalAttributeString ()) {
 				MemberType	    = opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1 ? null : (MemberTypes?) MemberTypes.Method,
 			});
 

external/Java.Interop/tools/generator/SourceWriters/BoundInterfacePropertyDeclaration.cs

@@ -35,7 +35,7 @@ public BoundInterfacePropertyDeclaration (GenBase gen, Property property, string
 
 				SourceWriterExtensions.AddSupportedOSPlatform (GetterAttributes, property.Getter, opt);
 
-				GetterAttributes.Add (new RegisterAttr (property.Getter.JavaName, property.Getter.JniSignature, property.Getter.ConnectorName + ":" + property.Getter.GetAdapterName (opt, adapter), additionalProperties: property.Getter.AdditionalAttributeString ()) {
+				GetterAttributes.Add (new RegisterAttr (property.Getter.JavaName, property.Getter.JniSignature, UnmanagedCallbackSupport.GetConnectorName (gen, property.Getter, opt) + ":" + property.Getter.GetAdapterName (opt, adapter), additionalProperties: property.Getter.AdditionalAttributeString ()) {
 					MemberType	    = opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1 ? null : (MemberTypes?) MemberTypes.Method,
 				});
 			}
@@ -50,7 +50,7 @@ public BoundInterfacePropertyDeclaration (GenBase gen, Property property, string
 
 				SourceWriterExtensions.AddSupportedOSPlatform (SetterAttributes, property.Setter, opt);
 
-				SetterAttributes.Add (new RegisterAttr (property.Setter.JavaName, property.Setter.JniSignature, property.Setter.ConnectorName + ":" + property.Setter.GetAdapterName (opt, adapter), additionalProperties: property.Setter.AdditionalAttributeString ()) {
+				SetterAttributes.Add (new RegisterAttr (property.Setter.JavaName, property.Setter.JniSignature, UnmanagedCallbackSupport.GetConnectorName (gen, property.Setter, opt) + ":" + property.Setter.GetAdapterName (opt, adapter), additionalProperties: property.Setter.AdditionalAttributeString ()) {
 					MemberType	    = opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1 ? null : (MemberTypes?) MemberTypes.Method,
 				});
 			}

external/Java.Interop/tools/generator/SourceWriters/BoundMethod.cs

@@ -82,7 +82,7 @@ public BoundMethod (GenBase type, Method method, CodeGenerationOptions opt, bool
 
 			SourceWriterExtensions.AddSupportedOSPlatform (Attributes, method, opt);
 
-			Attributes.Add (new RegisterAttr (method.JavaName, method.JniSignature, method.IsVirtual ? method.GetConnectorNameFull (opt) : string.Empty, additionalProperties: method.AdditionalAttributeString ()) {
+			Attributes.Add (new RegisterAttr (method.JavaName, method.JniSignature, method.IsVirtual ? UnmanagedCallbackSupport.GetConnectorNameFull (type, method, opt) : string.Empty, additionalProperties: method.AdditionalAttributeString ()) {
 				MemberType	    = opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1 ? null : (MemberTypes?) MemberTypes.Method,
 			});
 

external/Java.Interop/tools/generator/SourceWriters/BoundMethodAbstractDeclaration.cs

@@ -62,7 +62,7 @@ public BoundMethodAbstractDeclaration (GenBase gen, Method method, CodeGeneratio
 			SourceWriterExtensions.AddSupportedOSPlatform (Attributes, method, opt);
 
 			if (opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1) {
-				Attributes.Add (new RegisterAttr (method.JavaName, method.JniSignature, method.ConnectorName, additionalProperties: method.AdditionalAttributeString ()));
+				Attributes.Add (new RegisterAttr (method.JavaName, method.JniSignature, UnmanagedCallbackSupport.GetConnectorName (impl, method, opt), additionalProperties: method.AdditionalAttributeString ()));
 			}
 
 			SourceWriterExtensions.AddMethodCustomAttributes (Attributes, method);

external/Java.Interop/tools/generator/SourceWriters/BoundProperty.cs

@@ -97,7 +97,7 @@ public BoundProperty (GenBase gen, Property property, CodeGenerationOptions opt,
 				GetterComments.Add ($"// Metadata.xml XPath method reference: path=\"{gen.MetadataXPathReference}/method[@name='{property.Getter.JavaName}'{property.Getter.Parameters.GetMethodXPathPredicate ()}]\"");
 
 			if (opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1) {
-				GetterAttributes.Add (new RegisterAttr (property.Getter.JavaName, property.Getter.JniSignature, property.Getter.IsVirtual ? property.Getter.GetConnectorNameFull (opt) : string.Empty, additionalProperties: property.Getter.AdditionalAttributeString ()));
+				GetterAttributes.Add (new RegisterAttr (property.Getter.JavaName, property.Getter.JniSignature, property.Getter.IsVirtual ? UnmanagedCallbackSupport.GetPropertyConnectorNameFull (gen, property, property.Getter, opt) : string.Empty, additionalProperties: property.Getter.AdditionalAttributeString ()));
 			}
 
 			SourceWriterExtensions.AddMethodBody (GetBody, property.Getter, opt);
@@ -112,7 +112,7 @@ public BoundProperty (GenBase gen, Property property, CodeGenerationOptions opt,
 
 				SourceWriterExtensions.AddMethodCustomAttributes (SetterAttributes, property.Setter);
 				if (opt.CodeGenerationTarget != CodeGenerationTarget.JavaInterop1) {
-					SetterAttributes.Add (new RegisterAttr (property.Setter.JavaName, property.Setter.JniSignature, property.Setter.IsVirtual ? property.Setter.GetConnectorNameFull (opt) : string.Empty, additionalProperties: property.Setter.AdditionalAttributeString ()));
+					SetterAttributes.Add (new RegisterAttr (property.Setter.JavaName, property.Setter.JniSignature, property.Setter.IsVirtual ? UnmanagedCallbackSupport.GetPropertyConnectorNameFull (gen, property, property.Setter, opt) : string.Empty, additionalProperties: property.Setter.AdditionalAttributeString ()));
 				}
 
 				var pname = property.Setter.Parameters [0].Name;