C# ILGenerator.IsInstance方法代码示例

        /// <summary>
        /// Generates CIL for the expression.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        /// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
        public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
        {
            // Note: we use GetRawOperand() so that grouping operators are not ignored.
            var operand = this.GetRawOperand(0);

            // There is only one operand, and it can be either a reference or a function call.
            // We need to split the operand into a function and some arguments.
            // If the operand is a reference, it is equivalent to a function call with no arguments.
            if (operand is FunctionCallExpression)
            {
                // Emit the function instance first.
                var function = ((FunctionCallExpression)operand).Target;
                function.GenerateCode(generator, optimizationInfo);
                EmitConversion.ToAny(generator, function.ResultType);
            }
            else
            {
                // Emit the function instance first.
                operand.GenerateCode(generator, optimizationInfo);
                EmitConversion.ToAny(generator, operand.ResultType);
            }

            // Check the object really is a function - if not, throw an exception.
            generator.IsInstance(typeof(Library.FunctionInstance));
            generator.Duplicate();
            var endOfTypeCheck = generator.CreateLabel();
            generator.BranchIfNotNull(endOfTypeCheck);

            // Throw an nicely formatted exception.
            var targetValue = generator.CreateTemporaryVariable(typeof(object));
            generator.StoreVariable(targetValue);
            EmitHelpers.LoadScriptEngine(generator);
            generator.LoadString("TypeError");
            generator.LoadString("The new operator requires a function, found a '{0}' instead");
            generator.LoadInt32(1);
            generator.NewArray(typeof(object));
            generator.Duplicate();
            generator.LoadInt32(0);
            generator.LoadVariable(targetValue);
            generator.Call(ReflectionHelpers.TypeUtilities_TypeOf);
            generator.StoreArrayElement(typeof(object));
            generator.Call(ReflectionHelpers.String_Format);
            generator.LoadInt32(optimizationInfo.SourceSpan.StartLine);
            generator.LoadStringOrNull(optimizationInfo.Source.Path);
            generator.LoadStringOrNull(optimizationInfo.FunctionName);
            generator.NewObject(ReflectionHelpers.JavaScriptException_Constructor_Error);
            generator.Throw();
            generator.DefineLabelPosition(endOfTypeCheck);
            generator.ReleaseTemporaryVariable(targetValue);

            if (operand is FunctionCallExpression)
            {
                // Emit an array containing the function arguments.
                ((FunctionCallExpression)operand).GenerateArgumentsArray(generator, optimizationInfo);
            }
            else
            {
                // Emit an empty array.
                generator.LoadInt32(0);
                generator.NewArray(typeof(object));
            }

            // Call FunctionInstance.ConstructLateBound(argumentValues)
            generator.Call(ReflectionHelpers.FunctionInstance_ConstructLateBound);
        }

        /// <summary>
        /// Generates CIL for the in operator.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        /// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
        private void GenerateIn(ILGenerator generator, OptimizationInfo optimizationInfo)
        {
            // Emit the left-hand side expression and convert it to a string.
            this.Left.GenerateCode(generator, optimizationInfo);
            EmitConversion.ToString(generator, this.Left.ResultType);

            // Store the left-hand side expression in a temporary variable.
            var temp = generator.CreateTemporaryVariable(typeof(string));
            generator.StoreVariable(temp);

            // Emit the right-hand side expression.
            this.Right.GenerateCode(generator, optimizationInfo);
            EmitConversion.ToAny(generator, this.Right.ResultType);

            // Check the right-hand side is a javascript object - if not, throw an exception.
            generator.IsInstance(typeof(Library.ObjectInstance));
            generator.Duplicate();
            var endOfTypeCheck = generator.CreateLabel();
            generator.BranchIfNotNull(endOfTypeCheck);

            // Throw an nicely formatted exception.
            var rightValue = generator.CreateTemporaryVariable(typeof(object));
            generator.StoreVariable(rightValue);
            EmitHelpers.LoadScriptEngine(generator);
            generator.LoadString("TypeError");
            generator.LoadString("The in operator expected an object, but found '{0}' instead");
            generator.LoadInt32(1);
            generator.NewArray(typeof(object));
            generator.Duplicate();
            generator.LoadInt32(0);
            generator.LoadVariable(rightValue);
            generator.Call(ReflectionHelpers.TypeUtilities_TypeOf);
            generator.StoreArrayElement(typeof(object));
            generator.Call(ReflectionHelpers.String_Format);
            generator.LoadInt32(optimizationInfo.SourceSpan.StartLine);
            generator.LoadStringOrNull(optimizationInfo.Source.Path);
            generator.LoadStringOrNull(optimizationInfo.FunctionName);
            generator.NewObject(ReflectionHelpers.JavaScriptException_Constructor_Error);
            generator.Throw();
            generator.DefineLabelPosition(endOfTypeCheck);
            generator.ReleaseTemporaryVariable(rightValue);

            // Load the left-hand side expression from the temporary variable.
            generator.LoadVariable(temp);

            // Call ObjectInstance.HasProperty(object)
            generator.Call(ReflectionHelpers.ObjectInstance_HasProperty);

            // Allow the temporary variable to be reused.
            generator.ReleaseTemporaryVariable(temp);
        }

        /// <summary>
        /// Pops the value on the stack, converts it from one type to another, then pushes the
        /// result onto the stack.
        /// </summary>
        /// <param name="il"> The IL generator. </param>
        /// <param name="fromType"> The type to convert from. </param>
        /// <param name="toType"> The type to convert to. </param>
        private static void EmitTypeConversion(ILGenerator il, Type fromType, Type toType)
        {
            // If the source type equals the destination type, then there is nothing to do.
            if (fromType == toType)
                return;

            // Emit for each type of argument we support.
            if (toType == typeof(int))
                EmitConversion.ToInteger(il, PrimitiveTypeUtilities.ToPrimitiveType(fromType));
            else if (typeof(ObjectInstance).IsAssignableFrom(toType))
            {
                EmitConversion.Convert(il, PrimitiveTypeUtilities.ToPrimitiveType(fromType), PrimitiveType.Object);
                if (toType != typeof(ObjectInstance))
                {
                    // Convert to null if the from type isn't compatible with the to type.
                    // For example, if the target type is FunctionInstance and the from type is ArrayInstance, then pass null.
                    il.IsInstance(toType);
                }
            }
            else
                EmitConversion.Convert(il, PrimitiveTypeUtilities.ToPrimitiveType(fromType), PrimitiveTypeUtilities.ToPrimitiveType(toType));
        }

        /// <summary>
        /// Generates CIL for the expression.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        /// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
        public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
        {
            // Check if this is a direct call to eval().
            if (this.Target is NameExpression && ((NameExpression)this.Target).Name == "eval")
            {
                GenerateEval(generator, optimizationInfo);
                return;
            }

            // Emit the function instance first.
            ILLocalVariable targetBase = null;
            if (this.Target is MemberAccessExpression)
            {
                // The function is a member access expression (e.g. "Math.cos()").

                // Evaluate the left part of the member access expression.
                var baseExpression = ((MemberAccessExpression)this.Target).Base;
                baseExpression.GenerateCode(generator, optimizationInfo);
                EmitConversion.ToAny(generator, baseExpression.ResultType);
                targetBase = generator.CreateTemporaryVariable(typeof(object));
                generator.StoreVariable(targetBase);

                // Evaluate the right part of the member access expression.
                var memberAccessExpression = new MemberAccessExpression(((MemberAccessExpression)this.Target).Operator);
                memberAccessExpression.Push(new TemporaryVariableExpression(targetBase));
                memberAccessExpression.Push(((MemberAccessExpression)this.Target).GetOperand(1));
                memberAccessExpression.GenerateCode(generator, optimizationInfo);
                EmitConversion.ToAny(generator, this.Target.ResultType);
            }
            else
            {
                // Something else (e.g. "eval()").
                this.Target.GenerateCode(generator, optimizationInfo);
                EmitConversion.ToAny(generator, this.Target.ResultType);
            }

            // Check the object really is a function - if not, throw an exception.
            generator.IsInstance(typeof(Library.FunctionInstance));
            generator.Duplicate();
            var endOfTypeCheck = generator.CreateLabel();
            generator.BranchIfNotNull(endOfTypeCheck);

            // Throw an nicely formatted exception.
            generator.Pop();
            EmitHelpers.EmitThrow(generator, "TypeError", string.Format("'{0}' is not a function", this.Target.ToString()));
            generator.DefineLabelPosition(endOfTypeCheck);

            // Pass in the path, function name and line.
            generator.LoadStringOrNull(optimizationInfo.Source.Path);
            generator.LoadStringOrNull(optimizationInfo.FunctionName);
            generator.LoadInt32(optimizationInfo.SourceSpan.StartLine);

            // Generate code to produce the "this" value.  There are three cases.
            if (this.Target is NameExpression)
            {
                // 1. The function is a name expression (e.g. "parseInt()").
                //    In this case this = scope.ImplicitThisValue, if there is one, otherwise undefined.
                ((NameExpression)this.Target).GenerateThis(generator);
            }
            else if (this.Target is MemberAccessExpression)
            {
                // 2. The function is a member access expression (e.g. "Math.cos()").
                //    In this case this = Math.
                //var baseExpression = ((MemberAccessExpression)this.Target).Base;
                //baseExpression.GenerateCode(generator, optimizationInfo);
                //EmitConversion.ToAny(generator, baseExpression.ResultType);
                generator.LoadVariable(targetBase);
            }
            else
            {
                // 3. Neither of the above (e.g. "(function() { return 5 })()")
                //    In this case this = undefined.
                EmitHelpers.EmitUndefined(generator);
            }

            // Emit an array containing the function arguments.
            GenerateArgumentsArray(generator, optimizationInfo);

            // Call FunctionInstance.CallLateBound(thisValue, argumentValues)
            generator.Call(ReflectionHelpers.FunctionInstance_CallWithStackTrace);

            // Allow reuse of the temporary variable.
            if (targetBase != null)
                generator.ReleaseTemporaryVariable(targetBase);
        }

//.........这里部分代码省略.........
                        generator.LoadArgument(1);

                        bool inheritsFromObjectInstance = typeof(ObjectInstance).IsAssignableFrom(argument.Type);
                        if (argument.Type.IsClass == true && inheritsFromObjectInstance == false &&
                            argument.Type != typeof(string) && argument.Type != typeof(object))
                        {
                            // If the "this" object is an unsupported class, pass it through unmodified.
                            generator.CastClass(argument.Type);
                        }
                        else
                        {
                            if (argument.Type != typeof(object))
                            {
                                // If the target "this" object type is not of type object, throw an error if
                                // the value is undefined or null.
                                generator.Duplicate();
                                var temp = generator.CreateTemporaryVariable(typeof(object));
                                generator.StoreVariable(temp);
                                generator.LoadArgument(0);
                                generator.LoadVariable(temp);
                                generator.LoadString(binderMethod.Name);
                                generator.Call(ReflectionHelpers.TypeUtilities_VerifyThisObject);
                                generator.ReleaseTemporaryVariable(temp);
                            }

                            // Convert to the target type.
                            EmitTypeConversion(generator, typeof(object), argument.Type);

                            if (argument.Type != typeof(ObjectInstance) && inheritsFromObjectInstance == true)
                            {
                                // EmitConversionToObjectInstance can emit null if the toType is derived from ObjectInstance.
                                // Therefore, if the value emitted is null it means that the "thisObject" is a type derived
                                // from ObjectInstance (e.g. FunctionInstance) and the value provided is a different type
                                // (e.g. ArrayInstance).  In this case, throw an exception explaining that the function is
                                // not generic.
                                var endOfThrowLabel = generator.CreateLabel();
                                generator.Duplicate();
                                generator.BranchIfNotNull(endOfThrowLabel);
                                generator.LoadArgument(0);
                                EmitHelpers.EmitThrow(generator, "TypeError", string.Format("The method '{0}' is not generic", binderMethod.Name));
                                generator.DefineLabelPosition(endOfThrowLabel);
                            }
                        }
                        break;

                    case BinderArgumentSource.InputParameter:
                        if (argument.InputParameterIndex < argumentCount)
                        {
                            // Load the argument onto the stack.
                            generator.LoadArgument(2);
                            generator.LoadInt32(argument.InputParameterIndex);
                            generator.LoadArrayElement(typeof(object));

                            // Get some flags that apply to the parameter.
                            var parameterFlags = JSParameterFlags.None;
                            var parameterAttribute = argument.GetCustomAttribute<JSParameterAttribute>();
                            if (parameterAttribute != null)
                            {
                                if (argument.Type != typeof(ObjectInstance))
                                    throw new NotImplementedException("[JSParameter] is only supported for arguments of type ObjectInstance.");
                                parameterFlags = parameterAttribute.Flags;
                            }

                            if ((parameterFlags & JSParameterFlags.DoNotConvert) == 0)
                            {
                                // Convert the input parameter to the correct type.
                                EmitTypeConversion(generator, typeof(object), argument);
                            }
                            else
                            {
                                // Don't do argument conversion.
                                var endOfThrowLabel = generator.CreateLabel();
                                generator.IsInstance(typeof(ObjectInstance));
                                generator.Duplicate();
                                generator.BranchIfNotNull(endOfThrowLabel);
                                EmitHelpers.EmitThrow(generator, "TypeError", string.Format("Parameter {1} parameter of '{0}' must be an object", binderMethod.Name, argument.InputParameterIndex));
                                generator.DefineLabelPosition(endOfThrowLabel);
                            }
                        }
                        else
                        {
                            // The target method has more parameters than we have input values.
                            EmitUndefined(generator, argument);
                        }
                        break;
                }
            }

            // Emit the call.
            binderMethod.GenerateCall(generator);

            // Convert the return value.
            if (binderMethod.ReturnType == typeof(void))
                EmitHelpers.EmitUndefined(generator);
            else
                EmitTypeConversion(generator, binderMethod.ReturnType, typeof(object));

            // End the IL.
            generator.Complete();
        }

        /// <summary>
        /// Pops the value on the stack, converts it from an object to the given type, then pushes
        /// the result onto the stack.
        /// </summary>
        /// <param name="generator"> The IL generator. </param>
        /// <param name="toType"> The type to convert to. </param>
        /// <param name="convertToAddress"> <c>true</c> if the value is intended for use as an
        /// instance pointer; <c>false</c> otherwise. </param>
        internal static void EmitConversionToType(ILGenerator generator, Type toType, bool convertToAddress)
        {
            // Convert Null.Value to null if the target type is a reference type.
            ILLabel endOfNullCheck = null;
            if (toType.IsValueType == false)
            {
                var startOfElse = generator.CreateLabel();
                endOfNullCheck = generator.CreateLabel();
                generator.Duplicate();
                EmitHelpers.EmitNull(generator);
                generator.BranchIfNotEqual(startOfElse);
                generator.Pop();
                generator.LoadNull();
                generator.Branch(endOfNullCheck);
                generator.DefineLabelPosition(startOfElse);
            }

            switch (Type.GetTypeCode(toType))
            {
                case TypeCode.Boolean:
                    EmitConversion.ToBool(generator, PrimitiveType.Any);
                    break;
                case TypeCode.Byte:
                    EmitConversion.ToInt32(generator, PrimitiveType.Any);
                    break;
                case TypeCode.Char:
                    EmitConversion.ToString(generator, PrimitiveType.Any);
                    generator.Duplicate();
                    generator.Call(ReflectionHelpers.String_Length);
                    generator.LoadInt32(1);
                    var endOfCharCheck = generator.CreateLabel();
                    generator.BranchIfEqual(endOfCharCheck);
                    EmitHelpers.EmitThrow(generator, "TypeError", "Cannot convert string to char - the string must be exactly one character long");
                    generator.DefineLabelPosition(endOfCharCheck);
                    generator.LoadInt32(0);
                    generator.Call(ReflectionHelpers.String_GetChars);
                    break;
                case TypeCode.DBNull:
                    throw new NotSupportedException("DBNull is not a supported parameter type.");
                case TypeCode.Decimal:
                    EmitConversion.ToNumber(generator, PrimitiveType.Any);
                    generator.NewObject(ReflectionHelpers.Decimal_Constructor_Double);
                    break;
                case TypeCode.Double:
                    EmitConversion.ToNumber(generator, PrimitiveType.Any);
                    break;
                case TypeCode.Empty:
                    throw new NotSupportedException("Empty is not a supported return type.");
                case TypeCode.Int16:
                    EmitConversion.ToInt32(generator, PrimitiveType.Any);
                    break;
                case TypeCode.Int32:
                    EmitConversion.ToInt32(generator, PrimitiveType.Any);
                    break;
                case TypeCode.Int64:
                    EmitConversion.ToNumber(generator, PrimitiveType.Any);
                    generator.ConvertToInt64();
                    break;

                case TypeCode.DateTime:
                case TypeCode.Object:
                    // Check if the type must be unwrapped.
                    generator.Duplicate();
                    generator.IsInstance(typeof(Jurassic.Library.ClrInstanceWrapper));
                    var endOfUnwrapCheck = generator.CreateLabel();
                    generator.BranchIfFalse(endOfUnwrapCheck);

                    // Unwrap the wrapped instance.
                    generator.Call(ReflectionHelpers.ClrInstanceWrapper_GetWrappedInstance);
                    generator.DefineLabelPosition(endOfUnwrapCheck);

                    // Value types must be unboxed.
                    if (toType.IsValueType == true)
                    {
                        if (convertToAddress == true)
                            // Unbox.
                            generator.Unbox(toType);
                        else
                            // Unbox and copy to the stack.
                            generator.UnboxAny(toType);

                        //// Calling methods on value required the address of the value type, not the value type itself.
                        //if (argument.Source == BinderArgumentSource.ThisValue && argument.Type.IsValueType == true)
                        //{
                        //    var temp = generator.CreateTemporaryVariable(argument.Type);
                        //    generator.StoreVariable(temp);
                        //    generator.LoadAddressOfVariable(temp);
                        //    generator.ReleaseTemporaryVariable(temp);
                        //}
                    }


//.........这里部分代码省略.........