static CodeElementCollection <ICodeElement> CaptureSwiftOutputPostlude(string fileName)
        {
            //#if _MAC_TS_TEST_
            //            string path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), fileName);
            //#else
            //NSUrl[] urls = NSFileManager.DefaultManager.GetUrls(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomain.User);
            //string path = Path.Combine(urls[0].Path, fileName);
            //#endif

            //NSUrl[] urls = NSFileManager.DefaultManager.GetUrls(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomain.User);
            //string path = Path.Combine(urls[0].Path, fileName);
            //if (File.Exists(path))
            //{
            //    Console.Write(File.ReadAllText(path));
            //}

            CSCodeBlock  block  = new CSCodeBlock();
            CSIdentifier pathID = new CSIdentifier("path");

            block.Add(new CSIdentifier("\n#if _MAC_TS_TEST_\n"));
            block.Add(CSVariableDeclaration.VarLine(CSSimpleType.String, pathID,
                                                    new CSFunctionCall("Path.Combine", false,
                                                                       new CSIdentifier("Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)") +
                                                                       CSConstant.Val("/Documents/"),
                                                                       CSConstant.Val(fileName))));
            block.Add(new CSIdentifier("\n#else\n"));
            CSIdentifier urlID    = new CSIdentifier("urls");
            CSLine       urlsLine = CSVariableDeclaration.VarLine(new CSSimpleType("NSUrl", true), urlID,
                                                                  new CSFunctionCall("NSFileManager.DefaultManager.GetUrls", false,
                                                                                     new CSIdentifier("NSSearchPathDirectory.DocumentDirectory"),
                                                                                     new CSIdentifier("NSSearchPathDomain.User")));

            block.Add(urlsLine);


            CSLine pathLine = CSVariableDeclaration.VarLine(CSSimpleType.String, pathID,
                                                            new CSFunctionCall("Path.Combine", false,
                                                                               new CSArray1D(urlID.Name, CSConstant.Val(0)).Dot(new CSIdentifier("Path")),
                                                                               CSConstant.Val(fileName)));

            block.Add(pathLine);
            block.Add(new CSIdentifier("\n#endif\n"));

            CSCodeBlock ifBlock = new CSCodeBlock();
            CSLine      writer  = CSFunctionCall.FunctionCallLine("Console.Write", false, new CSFunctionCall("File.ReadAllText", false, pathID));

            ifBlock.Add(writer);
            ifBlock.Add(CSFunctionCall.FunctionCallLine("File.Delete", false, pathID));
            CSIfElse iftest = new CSIfElse(new CSFunctionCall("File.Exists", false, pathID), ifBlock);

            block.Add(iftest);
            return(block);
        }
Example #2
0
        void VirtualMethodException(string toAdd, string output)
        {
            string swiftCode = $"public enum MyErrorVME{toAdd} : Error {{\ncase itFailed\n}}\n" +
                               $"open class FooVME{toAdd} {{\npublic init() {{\n}}\n public final func doIt(doThrow:Bool) throws {{\n let _ = try throwIt(doThrow:doThrow)\n}}\n open func throwIt(doThrow: Bool) throws -> Int\n {{\n if doThrow {{\n throw MyErrorVME{toAdd}.itFailed\n}}\nelse {{\n return 5\n}}\n}}\n}}\n";
            CodeElementCollection <ICodeElement> callingCode = new CodeElementCollection <ICodeElement> ();

            CSClass fooOver = new CSClass(CSVisibility.Public, $"SubFooVME{toAdd}");

            fooOver.Inheritance.Add(new CSIdentifier($"FooVME{toAdd}"));
            CSCodeBlock overBody  = new CSCodeBlock();
            CSCodeBlock ifblock   = new CSCodeBlock();
            CSCodeBlock elseblock = new CSCodeBlock();

            ifblock.Add(new CSLine(new CSThrow(new CSFunctionCall("ArgumentException", true, CSConstant.Val("gotcha.")))));
            elseblock.Add(CSReturn.ReturnLine(CSConstant.Val(6)));
            CSIfElse ifElse = new CSIfElse(new CSIdentifier("doThrow"), ifblock, elseblock);

            overBody.Add(ifElse);

            CSMethod myThrowIt = new CSMethod(CSVisibility.Public,
                                              CSMethodKind.Override,
                                              new CSSimpleType("nint"),
                                              new CSIdentifier("ThrowIt"),
                                              new CSParameterList(new CSParameter(CSSimpleType.Bool, new CSIdentifier("doThrow"))), overBody);

            fooOver.Methods.Add(myThrowIt);

            CSCodeBlock tryBlock = new CSCodeBlock();
            CSLine      varLine  = CSVariableDeclaration.VarLine(new CSSimpleType($"SubFooVME{toAdd}"), "foo", new CSFunctionCall($"SubFooVME{toAdd}", true));

            tryBlock.Add(varLine);
            CSLine call = CSFunctionCall.FunctionCallLine("foo.DoIt", false, new CSIdentifier(toAdd));

            tryBlock.Add(call);
            CSCodeBlock catchBlock = new CSCodeBlock();

            catchBlock.Add(CSFunctionCall.FunctionCallLine("Console.Write", false, new CSIdentifier("e").Dot(new CSIdentifier("Message"))));
            CSTryCatch catcher = new CSTryCatch(tryBlock, typeof(SwiftException), "e", catchBlock);

            callingCode.Add(catcher);
            TestRunning.TestAndExecute(swiftCode, callingCode, output, testName: $"VirtualMethodException{toAdd}", otherClass: fooOver, platform: PlatformName.macOS);
        }
        public List <ICodeElement> MarshalFromLambdaReceiverToCSFunc(CSType thisType, string csProxyName, CSParameterList delegateParams,
                                                                     FunctionDeclaration funcDecl, CSType methodType, CSParameterList methodParams, string methodName, bool isObjC)
        {
            bool thisIsInterface = csProxyName != null;
            bool isIndexer       = funcDecl.IsSubscript;
            bool needsReturn     = methodType != null && methodType != CSSimpleType.Void;
            bool isSetter        = funcDecl.IsSubscriptSetter;
            bool returnIsGeneric = funcDecl.IsTypeSpecGeneric(funcDecl.ReturnTypeSpec);

            var entity = !returnIsGeneric?typeMapper.GetEntityForTypeSpec(funcDecl.ReturnTypeSpec) : null;

            var returnEntity = entity;
            var entityType   = !returnIsGeneric?typeMapper.GetEntityTypeForTypeSpec(funcDecl.ReturnTypeSpec) : EntityType.None;

            bool returnIsStruct   = needsReturn && entity != null && entity.IsStructOrEnum;
            bool returnIsClass    = needsReturn && entity != null && entity.EntityType == EntityType.Class;
            bool returnIsProtocol = needsReturn && ((entity != null && entity.EntityType == EntityType.Protocol) || entityType == EntityType.ProtocolList);
            bool returnIsTuple    = needsReturn && entityType == EntityType.Tuple;
            bool returnIsClosure  = needsReturn && entityType == EntityType.Closure;

            var callParams                    = new List <CSBaseExpression> ();
            var preMarshalCode                = new List <CSLine> ();
            var postMarshalCode               = new List <CSLine> ();
            CSBaseExpression valueExpr        = null;
            bool             marshalingThrows = false;


            if (isSetter)
            {
                var valueID = delegateParams [1].Name;
                valueExpr = valueID;
                var  swiftNewValue     = funcDecl.ParameterLists [1] [0];
                bool newValueIsGeneric = funcDecl.IsTypeSpecGeneric(funcDecl.PropertyType);
                entity = !newValueIsGeneric?typeMapper.GetEntityForTypeSpec(swiftNewValue.TypeSpec) : null;

                entityType = !newValueIsGeneric?typeMapper.GetEntityTypeForTypeSpec(swiftNewValue.TypeSpec) : EntityType.None;

                var isUnusualNewValue = IsUnusualParameter(entity, delegateParams [1]);

                if (entityType == EntityType.Class || entity.IsObjCProtocol)
                {
                    var csParmType = new CSSimpleType(entity.SharpNamespace + "." + entity.SharpTypeName);
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 26, "Inconceivable! The class type for a subscript was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(SwiftObjectRegistry));

                    var fullClassName = entity.Type.ToFullyQualifiedName(true);
                    valueExpr = NewClassCompiler.SafeMarshalClassFromIntPtr(valueID, csParmType, use, fullClassName, typeMapper, entity.IsObjCProtocol);
                }
                else if (entityType == EntityType.Protocol)
                {
                    var csParmType = new CSSimpleType(entity.SharpNamespace + "." + entity.SharpTypeName);
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 27, "Inconceivable! The protocol type for a subscript was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(StructMarshal));
                    use.AddIfNotPresent(typeof(SwiftObjectRegistry));
                    valueExpr = new CSFunctionCall($"SwiftObjectRegistry.Registry.InterfaceForExistentialContainer<{csParmType.ToString ()}>", false, valueID);
                }
                else if ((entityType == EntityType.Struct || entityType == EntityType.Enum) && !isUnusualNewValue)
                {
                    var csParmType = new CSSimpleType(entity.SharpNamespace + "." + entity.SharpTypeName);
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 28, $"Inconceivable! The {entityType} type for a subscript was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(StructMarshal));
                    string valMarshalName = MarshalEngine.Uniqueify("val", identifiersUsed);
                    var    valMarshalId   = new CSIdentifier(valMarshalName);

                    CSLine valDecl = CSVariableDeclaration.VarLine(csParmType, valMarshalId,
                                                                   new CSCastExpression(csParmType, new CSFunctionCall("StructMarshal.Marshaler.ToNet", false, valueID,
                                                                                                                       csParmType.Typeof())));
                    preMarshalCode.Add(valDecl);
                    valueExpr = valMarshalId;
                }
                else if (entityType == EntityType.Tuple)
                {
                    var csParmType = new CSSimpleType(entity.SharpNamespace + "." + entity.SharpTypeName);
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 29, "Inconceivable! The tuple type for a subscript was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(StructMarshal));
                    string valMarshalName = MarshalEngine.Uniqueify("val", identifiersUsed);
                    var    valMarshalId   = new CSIdentifier(valMarshalName);

                    var valDecl = CSVariableDeclaration.VarLine(csParmType, valMarshalId,
                                                                new CSCastExpression(csParmType, new CSFunctionCall("StructMarshal.Marshaler.ToNet", false, valueID,
                                                                                                                    csParmType.Typeof())));
                    preMarshalCode.Add(valDecl);
                    valueExpr = valMarshalId;
                }
                else if (newValueIsGeneric)
                {
                    var depthIndex = funcDecl.GetGenericDepthAndIndex(swiftNewValue.TypeSpec);
                    var genRef     = new CSGenericReferenceType(depthIndex.Item1, depthIndex.Item2);
                    if (genRef == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 30, "Inconceivable! The generic type for a parameter in a method was NOT a CSGenericReferenceType!");
                    }
                    use.AddIfNotPresent(typeof(StructMarshal));
                    string valMarshalName = MarshalEngine.Uniqueify("valTemp", identifiersUsed);
                    var    valMarshalId   = new CSIdentifier(valMarshalName);

                    var valDecl = CSVariableDeclaration.VarLine(genRef, valMarshalId,
                                                                new CSCastExpression(genRef, new CSFunctionCall("StructMarshal.Marshaler.ToNet", false,
                                                                                                                valueID, genRef.Typeof())));
                    preMarshalCode.Add(valDecl);
                    valueExpr = valMarshalId;
                }
            }

            int j = 0;
            int k = isSetter ? 1 : 0;

            for (int i = (funcDecl.HasThrows || returnIsStruct || returnIsProtocol || isSetter || returnIsGeneric) ? 2 : 1; i < delegateParams.Count; i++, j++, k++)
            {
                var  swiftParm     = funcDecl.ParameterLists [1] [k];
                bool parmIsGeneric = funcDecl.IsTypeSpecGeneric(swiftParm);
                entity = !parmIsGeneric?typeMapper.GetEntityForTypeSpec(swiftParm.TypeSpec) : null;

                entityType = !parmIsGeneric?typeMapper.GetEntityTypeForTypeSpec(swiftParm.TypeSpec) : EntityType.None;

                var isUnusualParameter = IsUnusualParameter(entity, delegateParams [i]);
                var csParm             = methodParams [j];

                if (entityType == EntityType.Class || (entity != null && entity.IsObjCProtocol))
                {
                    var csParmType = csParm.CSType as CSSimpleType;
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 31, "Inconceivable! The class type for a method was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(SwiftObjectRegistry));

                    var fullClassName = entity.Type.ToFullyQualifiedName(true);
                    var retrievecall  = NewClassCompiler.SafeMarshalClassFromIntPtr(delegateParams [0].Name, csParmType, use, fullClassName, typeMapper, entity.IsObjCProtocol);
                    if (csParm.ParameterKind == CSParameterKind.Out || csParm.ParameterKind == CSParameterKind.Ref)
                    {
                        string id = MarshalEngine.Uniqueify(delegateParams [i].Name.Name, identifiersUsed);
                        identifiersUsed.Add(id);
                        preMarshalCode.Add(CSFieldDeclaration.FieldLine(csParmType, id, retrievecall));
                        callParams.Add(new CSIdentifier(String.Format("{0} {1}",
                                                                      csParm.ParameterKind == CSParameterKind.Out ? "out" : "ref", id)));
                        postMarshalCode.Add(CSAssignment.Assign(delegateParams [i].Name,
                                                                NewClassCompiler.SafeBackingFieldAccessor(new CSIdentifier(id), use, entity.Type.ToFullyQualifiedName(true), typeMapper)));
                    }
                    else
                    {
                        callParams.Add(retrievecall);
                    }
                }
                else if (entityType == EntityType.Protocol)
                {
                    var thePtr     = new CSIdentifier(MarshalEngine.Uniqueify("p", identifiersUsed));
                    var csParmType = csParm.CSType as CSSimpleType;
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 32, "Inconceivable! The protocol type for a method was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(SwiftObjectRegistry));
                    string csParmProxyType = NewClassCompiler.CSProxyNameForProtocol(entity.Type.ToFullyQualifiedName(true), typeMapper);
                    if (csParmProxyType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 33, $"Unable to find C# interface type for protocol {entity.Type.ToFullyQualifiedName ()}");
                    }

                    var retrievecall = new CSFunctionCall($"SwiftObjectRegistry.Registry.InterfaceForExistentialContainer<{csParmType.Name}>", false, delegateParams [i].Name);
                    if (csParm.ParameterKind == CSParameterKind.Out || csParm.ParameterKind == CSParameterKind.Ref)
                    {
                        CSIdentifier id = new CSIdentifier(MarshalEngine.Uniqueify(delegateParams [i].Name.Name, identifiersUsed));
                        identifiersUsed.Add(id.Name);
                        preMarshalCode.Add(CSFieldDeclaration.FieldLine(csParmType, id.Name, retrievecall));
                        callParams.Add(new CSIdentifier(String.Format("{0} {1}",
                                                                      csParm.ParameterKind == CSParameterKind.Out ? "out" : "ref", id)));
                        postMarshalCode.Add(CSAssignment.Assign(delegateParams [i].Name,
                                                                new CSFunctionCall("SwiftExistentialContainer1", true,
                                                                                   new CSFunctionCall("SwiftObjectRegistry.Registry.ExistentialContainerForProtocol", false, id, csParmType.Typeof()))));
                    }
                    else
                    {
                        callParams.Add(retrievecall);
                    }
                }
                else if ((entityType == EntityType.Struct || entityType == EntityType.Enum) && !isUnusualParameter)
                {
                    var csParmType = csParm.CSType as CSSimpleType;
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 34, $"Inconceivable! The {entityType} type for a method was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(StructMarshal));
                    use.AddIfNotPresent(typeof(StructMarshal));
                    string valMarshalName = MarshalEngine.Uniqueify(delegateParams [i].Name + "Temp", identifiersUsed);
                    var    valMarshalId   = new CSIdentifier(valMarshalName);

                    var valDecl = CSVariableDeclaration.VarLine(csParmType, valMarshalId,
                                                                new CSCastExpression(csParmType, new CSFunctionCall("StructMarshal.Marshaler.ToNet", false, delegateParams [i].Name,
                                                                                                                    csParmType.Typeof())));
                    preMarshalCode.Add(valDecl);
                    callParams.Add(valMarshalId);
                }
                else if (entityType == EntityType.Tuple)
                {
                    var csParmType = csParm.CSType as CSSimpleType;
                    if (csParmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 35, "Inconceivable! The tuple type for a parameter in a method was NOT a CSSimpleType!");
                    }
                    use.AddIfNotPresent(typeof(StructMarshal));
                    string valMarshalName = MarshalEngine.Uniqueify(delegateParams [i].Name + "Temp", identifiersUsed);
                    var    valMarshalId   = new CSIdentifier(valMarshalName);

                    var valDecl = CSVariableDeclaration.VarLine(csParmType, valMarshalId,
                                                                new CSCastExpression(csParmType, new CSFunctionCall("StructMarshal.Marshaler.ToNet", false, delegateParams [i].Name,
                                                                                                                    csParmType.Typeof())));
                    preMarshalCode.Add(valDecl);
                    callParams.Add(valMarshalId);
                }
                else if (entityType == EntityType.Closure)
                {
                    // parm is a SwiftClosureRepresentation
                    // (FuncType)StructMarshal.Marshaler.MakeDelegateFromBlindClosure (arg, argTypes, returnType);
                    var argTypesId = new CSIdentifier(MarshalEngine.Uniqueify("argTypes" + delegateParams [i], identifiersUsed));
                    identifiersUsed.Add(argTypesId.Name);
                    var parmType = csParm.CSType as CSSimpleType;
                    if (parmType == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 44, "Inconceivable! The type for a closure should be a CSSimpleType");
                    }
                    var hasReturn      = parmType.GenericTypeName == "Func";
                    var returnType     = hasReturn ? (CSBaseExpression)parmType.GenericTypes [parmType.GenericTypes.Length - 1].Typeof() : CSConstant.Null;
                    var argTypesLength = hasReturn ? parmType.GenericTypes.Length - 1 : parmType.GenericTypes.Length;
                    var argTypes       = new CSBaseExpression [argTypesLength];
                    for (int idx = 0; idx < argTypesLength; idx++)
                    {
                        argTypes [idx] = parmType.GenericTypes [idx].Typeof();
                    }
                    var typeArr = new CSArray1DInitialized(CSSimpleType.Type, argTypes);

                    var closureExpr = new CSFunctionCall("StructMarshal.Marshaler.MakeDelegateFromBlindClosure", false, delegateParams [i].Name,
                                                         typeArr, returnType);
                    var castTo = new CSCastExpression(csParm.CSType, closureExpr);
                    callParams.Add(castTo);
                }
                else if (entityType == EntityType.ProtocolList)
                {
                    preMarshalCode.Add(CSFunctionCall.FunctionCallLine("throw new NotImplementedException", false, CSConstant.Val($"Argument {csParm.Name} is a protocol list type and can't be marshaled from a virtual method.")));
                    callParams.Add(CSConstant.Null);
                    marshalingThrows = true;
                }
                else if (parmIsGeneric)
                {
                    // parm is an IntPtr to some T
                    // to get T, we ask funcDecl for the depthIndex of T
                    // T someVal = (T)StructMarshal.Marshaler.ToNet(parm, typeof(T));
                    // someVal gets passed in
                    var genRef = csParm.CSType as CSGenericReferenceType;
                    if (genRef == null)
                    {
                        throw ErrorHelper.CreateError(ReflectorError.kTypeMapBase + 36, "Inconceivable! The generic type for a parameter in a method was NOT a CSGenericReferenceType!");
                    }
                    use.AddIfNotPresent(typeof(StructMarshal));
                    string valMarshalName = MarshalEngine.Uniqueify(delegateParams [i].Name + "Temp", identifiersUsed);
                    var    valMarshalId   = new CSIdentifier(valMarshalName);

                    var valDecl = CSVariableDeclaration.VarLine(genRef, valMarshalId,
                                                                new CSCastExpression(genRef, new CSFunctionCall("StructMarshal.Marshaler.ToNet", false,
                                                                                                                delegateParams [i].Name,
                                                                                                                genRef.Typeof())));
                    preMarshalCode.Add(valDecl);
                    callParams.Add(valMarshalId);
                }
                else
                {
                    if (csParm.ParameterKind == CSParameterKind.Out || csParm.ParameterKind == CSParameterKind.Ref)
                    {
                        callParams.Add(new CSIdentifier(String.Format("{0} {1}",
                                                                      csParm.ParameterKind == CSParameterKind.Out ? "out" : "ref", delegateParams [i].Name.Name)));
                    }
                    else
                    {
                        callParams.Add(delegateParams [i].Name);
                    }
                }
            }

            var body = new CSCodeBlock();

            if (isObjC)
            {
                use.AddIfNotPresent("ObjCRuntime");
            }
            else
            {
                use.AddIfNotPresent(typeof(SwiftObjectRegistry));
            }


            CSBaseExpression invoker = null;

            if (isIndexer)
            {
                if (thisIsInterface)
                {
                    invoker = new CSIndexExpression(
                        $"SwiftObjectRegistry.Registry.InterfaceForExistentialContainer<{thisType.ToString ()}> (self)",
                        false, callParams.ToArray());
                }
                else
                {
                    var registryCall = isObjC ?
                                       $"Runtime.GetNSObject<{thisType.ToString ()}> (self)" :
                                       $"SwiftObjectRegistry.Registry.CSObjectForSwiftObject <{thisType.ToString ()}> (self)";
                    invoker = new CSIndexExpression(registryCall, false, callParams.ToArray());
                }
            }
            else
            {
                if (thisIsInterface)
                {
                    invoker = new CSFunctionCall(
                        $"SwiftObjectRegistry.Registry.InterfaceForExistentialContainer<{thisType.ToString ()}> (self).{methodName}",
                        false, callParams.ToArray());
                }
                else
                {
                    var registryCall = isObjC ?
                                       $"Runtime.GetNSObject<{thisType.ToString ()}>(self).{methodName}" :
                                       $"SwiftObjectRegistry.Registry.CSObjectForSwiftObject <{thisType.ToString ()}> (self).{methodName}";
                    invoker = new CSFunctionCall(registryCall, false, callParams.ToArray());
                }
            }

            var    tryBlock   = funcDecl.HasThrows ? new CSCodeBlock() : null;
            var    catchBlock = funcDecl.HasThrows ? new CSCodeBlock() : null;
            var    altBody    = tryBlock ?? body;
            string catchName  = MarshalEngine.Uniqueify("e", identifiersUsed);
            var    catchID    = new CSIdentifier(catchName);


            altBody.AddRange(preMarshalCode);
            if (marshalingThrows)
            {
                return(altBody);
            }

            if (funcDecl.HasThrows || needsReturn)               // function that returns or getter
            {
                if (funcDecl.HasThrows)
                {
                    use.AddIfNotPresent(typeof(SwiftError));
                    use.AddIfNotPresent(typeof(Tuple));
                    use.AddIfNotPresent(typeof(StructMarshal));
                    CSType returnTuple = null;
                    if (needsReturn)
                    {
                        returnTuple = new CSSimpleType("Tuple", false,
                                                       methodType,
                                                       new CSSimpleType(typeof(SwiftError)),
                                                       CSSimpleType.Bool);
                    }
                    else
                    {
                        returnTuple = new CSSimpleType("Tuple", false,
                                                       new CSSimpleType(typeof(SwiftError)),
                                                       CSSimpleType.Bool);
                    }


                    if (needsReturn)
                    {
                        string retvalName = MarshalEngine.Uniqueify("retval", identifiersUsed);
                        var    retvalId   = new CSIdentifier(retvalName);
                        altBody.Add(CSFieldDeclaration.VarLine(methodType, retvalId, invoker));
                        postMarshalCode.Add(CSFunctionCall.FunctionCallLine("StructMarshal.Marshaler.ToSwift", false,
                                                                            methodType.Typeof(),
                                                                            retvalId,
                                                                            delegateParams [0].Name));
                        altBody.Add(CSFunctionCall.FunctionCallLine("StructMarshal.Marshaler.SetErrorNotThrown", false,
                                                                    delegateParams [0].Name, returnTuple.Typeof()));
                    }
                    else
                    {
                        if (isSetter)
                        {
                            altBody.Add(CSAssignment.Assign(invoker, CSAssignmentOperator.Assign, valueExpr));
                        }
                        else
                        {
                            altBody.Add(new CSLine(invoker));
                        }
                        altBody.Add(CSFunctionCall.FunctionCallLine("StructMarshal.Marshaler.SetErrorNotThrown", false,
                                                                    delegateParams [0].Name, returnTuple.Typeof()));
                    }
                    string swiftError           = MarshalEngine.Uniqueify("err", identifiersUsed);
                    var    swiftErrorIdentifier = new CSIdentifier(swiftError);
                    catchBlock.Add(CSFieldDeclaration.VarLine(new CSSimpleType(typeof(SwiftError)), swiftErrorIdentifier,
                                                              new CSFunctionCall("SwiftError.FromException", false, catchID)));
                    catchBlock.Add(CSFunctionCall.FunctionCallLine("StructMarshal.Marshaler.SetErrorThrown", false,
                                                                   delegateParams [0].Name,
                                                                   swiftErrorIdentifier,
                                                                   returnTuple.Typeof()));
                }
                else
                {
                    if (returnIsClass)
                    {
                        string       retvalName = MarshalEngine.Uniqueify("retval", identifiersUsed);
                        CSIdentifier retvalId   = new CSIdentifier(retvalName);
                        altBody.Add(CSFieldDeclaration.VarLine(methodType, retvalId, invoker));
                        postMarshalCode.Add(CSReturn.ReturnLine(
                                                NewClassCompiler.SafeBackingFieldAccessor(retvalId, use, returnEntity.Type.ToFullyQualifiedName(), typeMapper)));
                    }
                    else if (returnIsProtocol)
                    {
                        string retvalName = MarshalEngine.Uniqueify("retval", identifiersUsed);
                        identifiersUsed.Add(retvalName);
                        var retvalId = new CSIdentifier(retvalName);
                        altBody.Add(CSFieldDeclaration.VarLine(methodType, retvalId, invoker));
                        var returnContainer = MarshalEngine.Uniqueify("returnContainer", identifiersUsed);
                        identifiersUsed.Add(returnContainer);
                        var returnContainerId = new CSIdentifier(returnContainer);
                        var protoGetter       = new CSFunctionCall($"SwiftObjectRegistry.Registry.ExistentialContainerForProtocols", false, retvalId, methodType.Typeof());
                        var protoDecl         = CSVariableDeclaration.VarLine(CSSimpleType.Var, returnContainerId, protoGetter);
                        var marshalBack       = CSFunctionCall.FunctionCallLine($"{returnContainer}.CopyTo", delegateParams [0].Name);
                        postMarshalCode.Add(protoDecl);
                        postMarshalCode.Add(marshalBack);
                    }
                    else if (returnIsStruct)
                    {
                        // non-blitable means that the parameter is an IntPtr and we can call the
                        // marshaler to copy into it
                        use.AddIfNotPresent(typeof(StructMarshal));
                        var marshalCall = CSFunctionCall.FunctionCallLine("StructMarshal.Marshaler.ToSwift", false,
                                                                          invoker, delegateParams [0].Name);
                        altBody.Add(marshalCall);
                    }
                    else if (returnIsTuple)
                    {
                        // non-blitable means that the parameter is an IntPtr and we can call the
                        // marshaler to copy into it
                        use.AddIfNotPresent(typeof(StructMarshal));
                        var marshalCall = CSFunctionCall.FunctionCallLine("StructMarshal.Marshaler.ToSwift", false,
                                                                          invoker, delegateParams [0].Name);
                        altBody.Add(marshalCall);
                    }
                    else if (returnIsGeneric)
                    {
                        // T retval = invoker();
                        // if (retval is ISwiftObject) {
                        //     Marshal.WriteIntPtr(delegateParams [0].Name, ((ISwiftObject)retval).SwiftObject);
                        // }
                        // else {
                        //    StructMarshal.Marshaler.ToSwift(typeof(T), retval, delegateParams[0].Name);
                        // }
                        string retvalName = MarshalEngine.Uniqueify("retval", identifiersUsed);
                        var    retvalId   = new CSIdentifier(retvalName);
                        altBody.Add(CSFieldDeclaration.VarLine(methodType, retvalId, invoker));
                        var ifClause = new CSCodeBlock();
                        ifClause.Add(CSFunctionCall.FunctionCallLine("Marshal.WriteIntPtr", false,
                                                                     delegateParams [0].Name,
                                                                     new CSParenthesisExpression(new CSCastExpression("ISwiftObject", retvalId)).Dot(NewClassCompiler.kSwiftObjectGetter)));
                        var elseClause = new CSCodeBlock();
                        elseClause.Add(CSFunctionCall.FunctionCallLine("StructMarshal.Marshaler.ToSwift", false,
                                                                       methodType.Typeof(),
                                                                       retvalId,
                                                                       delegateParams [0].Name));
                        CSBaseExpression ifExpr = new CSSimpleType("ISwiftObject").Typeof().Dot(new CSFunctionCall("IsAssignableFrom", false,
                                                                                                                   methodType.Typeof()));

                        var retTest = new CSIfElse(ifExpr, ifClause, elseClause);
                        altBody.Add(retTest);
                    }
                    else
                    {
                        if (returnIsClosure)
                        {
                            invoker = MarshalEngine.BuildBlindClosureCall(invoker, methodType as CSSimpleType, use);
                        }
                        if (postMarshalCode.Count > 0)
                        {
                            string       retvalName = MarshalEngine.Uniqueify("retval", identifiersUsed);
                            CSIdentifier retvalId   = new CSIdentifier(retvalName);
                            altBody.Add(CSFieldDeclaration.VarLine(methodType, retvalId, invoker));
                            postMarshalCode.Add(CSReturn.ReturnLine(retvalId));
                        }
                        else
                        {
                            altBody.Add(CSReturn.ReturnLine(invoker));
                        }
                    }
                }
            }
            else                 // no return or setter
            {
                if (isSetter)
                {
                    altBody.Add(CSAssignment.Assign(invoker, CSAssignmentOperator.Assign, valueExpr));
                }
                else
                {
                    altBody.Add(new CSLine(invoker));
                }
            }
            altBody.AddRange(postMarshalCode);

            if (funcDecl.HasThrows)
            {
                body.Add(new CSTryCatch(tryBlock, new CSCatch(typeof(Exception), catchName, catchBlock)));
            }
            return(body);
        }