private void AddOverrider(MethodInfo method, Reference invocationHandler)
        {
            var overrider = _emitter.CreateMethod(method.Name, MethodAttributes.Public | MethodAttributes.Virtual, method);

            overrider.AddCustomAttribute(new CustomAttributeBuilder(s_attributeConstructor, new object[0]));

            Reference      targetReference       = GetTargetReference();
            Expression     overriddenMethodToken = new MethodTokenExpression(method);
            LocalReference argsLocal             = CopyArgumentsToLocalVariable(overrider);
            Expression     baseMethodInvoker     = GetBaseInvokerExpression(method);

            TypeReference handlerReference = new TypeReferenceWrapper(invocationHandler, typeof(MethodInvocationHandler));

            Expression[] handlerArgs = new Expression[] { targetReference.ToExpression(), overriddenMethodToken, argsLocal.ToExpression(), baseMethodInvoker };

            Expression handlerInvocation = new VirtualMethodInvocationExpression(handlerReference, s_handlerInvokeMethod, handlerArgs);

            if (method.ReturnType != typeof(void))
            {
                overrider.ImplementByReturning(new ConvertExpression(method.ReturnType, typeof(object), handlerInvocation));
            }
            else
            {
                overrider.AddStatement(new ExpressionStatement(handlerInvocation));
                overrider.AddStatement(new PopStatement());
                overrider.ImplementByReturningVoid();
            }
        }
        protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, ClassEmitter @class,
                                                                ProxyGenerationOptions options, INamingScope namingScope)
        {
            var invocationType = invocation;

            Trace.Assert(MethodToOverride.IsGenericMethod == invocationType.IsGenericTypeDefinition());
            var genericArguments = TypeExtender.EmptyTypes;

            var constructor = invocation.GetConstructors()[0];

            Expression proxiedMethodTokenExpression;

            if (MethodToOverride.IsGenericMethod)
            {
                // bind generic method arguments to invocation's type arguments
                genericArguments = emitter.MethodBuilder.GetGenericArguments();
                invocationType   = invocationType.MakeGenericType(genericArguments);

                constructor = TypeBuilder.GetConstructor(invocationType, constructor);

                // Not in the cache: generic method
                proxiedMethodTokenExpression = new MethodTokenExpression(MethodToOverride.MakeGenericMethod(genericArguments));
            }
            else
            {
                var proxiedMethodToken = @class.CreateStaticField(namingScope.GetUniqueName("token_" + MethodToOverride.Name),
                                                                  typeof(IMethodInfo));

                @class.ClassConstructor.CodeBuilder.AddStatement(new AssignStatement(proxiedMethodToken,
                                                                                     new MethodTokenExpression(MethodToOverride)));

                proxiedMethodTokenExpression = proxiedMethodToken.ToExpression();
            }

            var dereferencedArguments = IndirectReference.WrapIfByRef(emitter.Arguments);
            var hasByRefArguments     = HasByRefArguments(emitter.Arguments);

            var arguments = GetCtorArguments(@class, namingScope, proxiedMethodTokenExpression,
                                             dereferencedArguments);
            var ctorArguments = ModifyArguments(@class, arguments);

            var invocationLocal = emitter.CodeBuilder.DeclareLocal(invocationType);

            emitter.CodeBuilder.AddStatement(new AssignStatement(invocationLocal,
                                                                 new NewInstanceExpression(constructor, ctorArguments)));

            if (MethodToOverride.ContainsGenericParameters)
            {
                EmitLoadGenricMethodArguments(emitter, MethodToOverride.MakeGenericMethod(genericArguments), invocationLocal);
            }

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new TryStatement());
            }

            var proceed = new ExpressionStatement(new MethodInvocationExpression(invocationLocal, InvocationMethods.Proceed));

            emitter.CodeBuilder.AddStatement(proceed);

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new FinallyStatement());
            }

            GeneratorUtil.CopyOutAndRefParameters(dereferencedArguments, invocationLocal, MethodToOverride, emitter);

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new EndExceptionBlockStatement());
            }

            if (MethodToOverride.ReturnType != typeof(void))
            {
                var getRetVal = new MethodInvocationExpression(invocationLocal, InvocationMethods.GetReturnValue);
                emitter.CodeBuilder.AddStatement(new ReturnStatement(new ConvertExpression(emitter.ReturnType, getRetVal)));
            }
            else
            {
                emitter.CodeBuilder.AddStatement(new ReturnStatement());
            }

            return(emitter);
        }
        protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, ClassEmitter @class, INamingScope namingScope)
        {
            var invocationType = invocation;

            Trace.Assert(MethodToOverride.IsGenericMethod == invocationType.IsGenericTypeDefinition);
            var genericArguments = Type.EmptyTypes;

            var constructor = invocation.GetConstructors()[0];

            Expression proxiedMethodTokenExpression;

            if (MethodToOverride.IsGenericMethod)
            {
                // bind generic method arguments to invocation's type arguments
                genericArguments = emitter.MethodBuilder.GetGenericArguments();
                invocationType   = invocationType.MakeGenericType(genericArguments);
                constructor      = TypeBuilder.GetConstructor(invocationType, constructor);

                // Not in the cache: generic method
                proxiedMethodTokenExpression = new MethodTokenExpression(MethodToOverride.MakeGenericMethod(genericArguments));
            }
            else
            {
                var proxiedMethodToken = @class.CreateStaticField(namingScope.GetUniqueName("token_" + MethodToOverride.Name), typeof(MethodInfo));
                @class.ClassConstructor.CodeBuilder.AddStatement(new AssignStatement(proxiedMethodToken, new MethodTokenExpression(MethodToOverride)));

                proxiedMethodTokenExpression = proxiedMethodToken.ToExpression();
            }

            var methodInterceptors = SetMethodInterceptors(@class, namingScope, emitter, proxiedMethodTokenExpression);

            var dereferencedArguments = IndirectReference.WrapIfByRef(emitter.Arguments);
            var hasByRefArguments     = HasByRefArguments(emitter.Arguments);

            var arguments     = GetCtorArguments(@class, proxiedMethodTokenExpression, dereferencedArguments, methodInterceptors);
            var ctorArguments = ModifyArguments(@class, arguments);

            var invocationLocal = emitter.CodeBuilder.DeclareLocal(invocationType);

            emitter.CodeBuilder.AddStatement(new AssignStatement(invocationLocal,
                                                                 new NewInstanceExpression(constructor, ctorArguments)));

            if (MethodToOverride.ContainsGenericParameters)
            {
                EmitLoadGenricMethodArguments(emitter, MethodToOverride.MakeGenericMethod(genericArguments), invocationLocal);
            }

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new TryStatement());
            }

            var proceed = new ExpressionStatement(new MethodInvocationExpression(invocationLocal, InvocationMethods.Proceed));

            emitter.CodeBuilder.AddStatement(proceed);

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new FinallyStatement());
            }

            GeneratorUtil.CopyOutAndRefParameters(dereferencedArguments, invocationLocal, MethodToOverride, emitter);

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new EndExceptionBlockStatement());
            }

            if (MethodToOverride.ReturnType != typeof(void))
            {
                var getRetVal = new MethodInvocationExpression(invocationLocal, InvocationMethods.GetReturnValue);

                // Emit code to ensure a value type return type is not null, otherwise the cast will cause a null-deref
                if (emitter.ReturnType.IsValueType && !emitter.ReturnType.IsNullableType())
                {
                    LocalReference returnValue = emitter.CodeBuilder.DeclareLocal(typeof(object));
                    emitter.CodeBuilder.AddStatement(new AssignStatement(returnValue, getRetVal));

                    emitter.CodeBuilder.AddExpression(new IfNullExpression(returnValue, new ThrowStatement(typeof(InvalidOperationException),
                                                                                                           "Interceptors failed to set a return value, or swallowed the exception thrown by the target")));
                }

                // Emit code to return with cast from ReturnValue
                emitter.CodeBuilder.AddStatement(new ReturnStatement(new ConvertExpression(emitter.ReturnType, getRetVal)));
            }
            else
            {
                emitter.CodeBuilder.AddStatement(new ReturnStatement());
            }

            return(emitter);
        }
Exemple #4
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        protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, ClassEmitter @class,
                                                                ProxyGenerationOptions options, INamingScope namingScope)
        {
            var invocationType = invocation;

            Trace.Assert(MethodToOverride.IsGenericMethod == invocationType.IsGenericTypeDefinition());
            var genericArguments = TypeExtender.EmptyTypes;

            var constructor = invocation.GetConstructors()[0];

            Expression proxiedMethodTokenExpression;

            if (MethodToOverride.IsGenericMethod)
            {
                // bind generic method arguments to invocation's type arguments
                genericArguments = emitter.MethodBuilder.GetGenericArguments();
                invocationType   = invocationType.MakeGenericType(genericArguments);
                constructor      = TypeBuilder.GetConstructor(invocationType, constructor);

                // Not in the cache: generic method
                proxiedMethodTokenExpression = new MethodTokenExpression(MethodToOverride.MakeGenericMethod(genericArguments));
            }
            else
            {
                var proxiedMethodToken = @class.CreateStaticField(namingScope.GetUniqueName("token_" + MethodToOverride.Name),
                                                                  typeof(MethodInfo));
                @class.ClassConstructor.CodeBuilder.AddStatement(new AssignStatement(proxiedMethodToken,
                                                                                     new MethodTokenExpression(MethodToOverride)));

                proxiedMethodTokenExpression = proxiedMethodToken.ToExpression();
            }

            var dereferencedArguments = IndirectReference.WrapIfByRef(emitter.Arguments);
            var hasByRefArguments     = HasByRefArguments(emitter.Arguments);

            var arguments = GetCtorArguments(@class, namingScope, proxiedMethodTokenExpression,
                                             dereferencedArguments);
            var ctorArguments = ModifyArguments(@class, arguments);

            var invocationLocal = emitter.CodeBuilder.DeclareLocal(invocationType);

            emitter.CodeBuilder.AddStatement(new AssignStatement(invocationLocal,
                                                                 new NewInstanceExpression(constructor, ctorArguments)));

            if (MethodToOverride.ContainsGenericParameters)
            {
                EmitLoadGenricMethodArguments(emitter, MethodToOverride.MakeGenericMethod(genericArguments), invocationLocal);
            }

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new TryStatement());
            }

            var proceed = new ExpressionStatement(new MethodInvocationExpression(invocationLocal, InvocationMethods.Proceed));

            emitter.CodeBuilder.AddStatement(proceed);

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new FinallyStatement());
            }

            GeneratorUtil.CopyOutAndRefParameters(dereferencedArguments, invocationLocal, MethodToOverride, emitter);

            if (hasByRefArguments)
            {
                emitter.CodeBuilder.AddStatement(new EndExceptionBlockStatement());
            }

            if (MethodToOverride.ReturnType != typeof(void))
            {
                // Emit code to return with cast from ReturnValue

                // @mbrit - 2012-05-31 - see the note associated with the GetReturnValueForWinRt declaration
                // for more information on this...

                var useWinRtGenericHandler = false;
#if NETFX_CORE
                if (emitter.ReturnType == typeof(int) || emitter.ReturnType == typeof(bool))
                {
                    useWinRtGenericHandler = true;
                }
#endif
                if (!(useWinRtGenericHandler))
                {
                    var getRetVal = new MethodInvocationExpression(invocationLocal, InvocationMethods.GetReturnValue);
                    emitter.CodeBuilder.AddStatement(new ReturnStatement(new ConvertExpression(emitter.ReturnType, getRetVal)));
                }
                else
                {
#if NETFX_CORE
                    var grvArgs   = new Type[] { emitter.ReturnType };
                    var grvCall   = InvocationMethods.GetReturnValueForWinRt.MakeGenericMethod(grvArgs);
                    var getRetVal = new MethodInvocationExpression(invocationLocal, grvCall);
                    emitter.CodeBuilder.AddStatement(new ReturnStatement(getRetVal));
#endif
                }
            }
            else
            {
                emitter.CodeBuilder.AddStatement(new ReturnStatement());
            }

            return(emitter);
        }