C# ILGenerator.CastClass方法代码示例

        /// <summary>
        /// Stores the value on the top of the stack in the reference.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        /// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
        /// <param name="valueType"> The primitive type of the value that is on the top of the stack. </param>
        /// <param name="throwIfUnresolvable"> <c>true</c> to throw a ReferenceError exception if
        /// the name is unresolvable; <c>false</c> to create a new property instead. </param>
        public void GenerateSet(ILGenerator generator, OptimizationInfo optimizationInfo, PrimitiveType valueType, bool throwIfUnresolvable)
        {
            // The value is initially on the top of the stack but is stored in this variable
            // at the last possible moment.
            ILLocalVariable value = null;

            var scope = this.Scope;
            ILLocalVariable scopeVariable = null;
            var endOfSet = generator.CreateLabel();
            do
            {
                if (scope is DeclarativeScope)
                {
                    // Get information about the variable.
                    var variable = scope.GetDeclaredVariable(this.Name);
                    if (variable != null)
                    {
                        // The variable was declared in this scope.

                        if (scope.ExistsAtRuntime == false)
                        {
                            // The scope has been optimized away.  The value of the variable is stored
                            // in an ILVariable.

                            // Declare an IL local variable if no storage location has been allocated yet.
                            if (variable.Store == null)
                                variable.Store = generator.DeclareVariable(typeof(object), variable.Name);

                            if (value == null)
                            {
                                // The value to store is on the top of the stack - convert it to the
                                // storage type of the variable.
                                EmitConversion.Convert(generator, valueType, variable.Type, optimizationInfo);
                            }
                            else
                            {
                                // The value to store is in a temporary variable.
                                generator.LoadVariable(value);
                                EmitConversion.Convert(generator, PrimitiveType.Any, variable.Type, optimizationInfo);
                            }

                            // Store the value in the variable.
                            generator.StoreVariable(variable.Store);
                        }
                        else if (variable.Writable == true)
                        {
                            if (value == null)
                            {
                                // The value to store is on the top of the stack - convert it to an
                                // object and store it in a temporary variable.
                                EmitConversion.Convert(generator, valueType, PrimitiveType.Any, optimizationInfo);
                                value = generator.CreateTemporaryVariable(typeof(object));
                                generator.StoreVariable(value);
                            }

                            // scope.Values[index] = value
                            if (scopeVariable == null)
                                EmitHelpers.LoadScope(generator);
                            else
                                generator.LoadVariable(scopeVariable);
                            generator.CastClass(typeof(DeclarativeScope));
                            generator.Call(ReflectionHelpers.DeclarativeScope_Values);
                            generator.LoadInt32(variable.Index);
                            generator.LoadVariable(value);
                            generator.StoreArrayElement(typeof(object));
                        }
                        else
                        {
                            // The variable exists, but is read-only.
                            // Pop the value off the stack (if it is still there).
                            if (value == null)
                                generator.Pop();
                        }

                        // The variable was found - no need to search any more parent scopes.
                        break;
                    }
                    else
                    {
                        // The variable was not defined at compile time, but may have been
                        // introduced by an eval() statement.
                        if (optimizationInfo.MethodOptimizationHints.HasEval == true)
                        {
                            if (value == null)
                            {
                                // The value to store is on the top of the stack - convert it to an
                                // object and store it in a temporary variable.
                                EmitConversion.Convert(generator, valueType, PrimitiveType.Any, optimizationInfo);
                                value = generator.CreateTemporaryVariable(typeof(object));
                                generator.StoreVariable(value);
                            }

//.........这里部分代码省略.........

        /// <summary>
        /// Generates code to push the "this" value for a function call.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        public void GenerateThis(ILGenerator generator)
        {
            // Optimization: if there are no with scopes, simply emit undefined.
            bool scopeChainHasWithScope = false;
            var scope = this.Scope;
            do
            {
                if (scope is ObjectScope && ((ObjectScope)scope).ProvidesImplicitThisValue == true)
                {
                    scopeChainHasWithScope = true;
                    break;
                }
                scope = scope.ParentScope;
            } while (scope != null);

            if (scopeChainHasWithScope == false)
            {
                // No with scopes in the scope chain, use undefined as the "this" value.
                EmitHelpers.EmitUndefined(generator);
                return;
            }

            var end = generator.CreateLabel();

            scope = this.Scope;
            ILLocalVariable scopeVariable = generator.CreateTemporaryVariable(typeof(Scope));
            EmitHelpers.LoadScope(generator);
            generator.StoreVariable(scopeVariable);

            do
            {
                if (scope is DeclarativeScope)
                {
                    if (scope.HasDeclaredVariable(this.Name))
                    {
                        // The variable exists but declarative scopes always produce undefined for
                        // the "this" value.
                        EmitHelpers.EmitUndefined(generator);
                        break;
                    }
                }
                else
                {
                    var objectScope = (ObjectScope)scope;

                    // Check if the property exists by calling scope.ScopeObject.HasProperty(propertyName)
                    if (objectScope.ProvidesImplicitThisValue == false)
                        EmitHelpers.EmitUndefined(generator);
                    generator.LoadVariable(scopeVariable);
                    generator.CastClass(typeof(ObjectScope));
                    generator.Call(ReflectionHelpers.ObjectScope_ScopeObject);
                    if (objectScope.ProvidesImplicitThisValue == true)
                        generator.Duplicate();
                    generator.LoadString(this.Name);
                    generator.Call(ReflectionHelpers.ObjectInstance_HasProperty);
                    generator.BranchIfTrue(end);
                    generator.Pop();

                    // If the name is not defined, use undefined for the "this" value.
                    if (scope.ParentScope == null)
                    {
                        EmitHelpers.EmitUndefined(generator);
                    }
                }

                // Try the parent scope.
                if (scope.ParentScope != null && scope.ExistsAtRuntime == true)
                {
                    generator.LoadVariable(scopeVariable);
                    generator.Call(ReflectionHelpers.Scope_ParentScope);
                    generator.StoreVariable(scopeVariable);
                }
                scope = scope.ParentScope;

            } while (scope != null);

            // Release the temporary variable.
            generator.ReleaseTemporaryVariable(scopeVariable);

            // Define a label at the end.
            generator.DefineLabelPosition(end);
        }

        /// <summary>
        /// Pushes the value of the reference onto the stack.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        /// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
        /// <param name="throwIfUnresolvable"> <c>true</c> to throw a ReferenceError exception if
        /// the name is unresolvable; <c>false</c> to output <c>null</c> instead. </param>
        public void GenerateGet(ILGenerator generator, OptimizationInfo optimizationInfo, bool throwIfUnresolvable)
        {
            // This method generates code to retrieve the value of a variable, given the name of
            // variable and scope in which the variable is being referenced.  The variable was
            // not necessary declared in this scope - it might be declared in any of the parent
            // scopes (together called a scope chain).  The general algorithm is to start at the
            // head of the chain and search backwards until the variable is found.  There are
            // two types of scopes: declarative scopes and object scopes.  Object scopes are hard -
            // it cannot be known at compile time whether the variable exists or not so runtime
            // checks have to be inserted.  Declarative scopes are easier - variables have to be
            // declared and cannot be deleted.  There is one tricky bit: new variables can be
            // introduced into a declarative scope at runtime by a non-strict eval() statement.
            // Even worse, variables that were introduced by means of an eval() *can* be deleted.

            var scope = this.Scope;
            ILLocalVariable scopeVariable = null;
            var endOfGet = generator.CreateLabel();
            do
            {
                if (scope is DeclarativeScope)
                {
                    // The variable was declared in this scope.
                    var variable = scope.GetDeclaredVariable(this.Name);

                    if (variable != null)
                    {
                        if (scope.ExistsAtRuntime == false)
                        {
                            // The scope has been optimized away.  The value of the variable is stored
                            // in an ILVariable.

                            // Declare an IL local variable if no storage location has been allocated yet.
                            if (variable.Store == null)
                                variable.Store = generator.DeclareVariable(typeof(object), variable.Name);

                            // Load the value from the variable.
                            generator.LoadVariable(variable.Store);

                            // Ensure that we match ResultType.
                            EmitConversion.Convert(generator, variable.Type, this.ResultType, optimizationInfo);
                        }
                        else
                        {
                            // scope.Values[index]
                            if (scopeVariable == null)
                                EmitHelpers.LoadScope(generator);
                            else
                                generator.LoadVariable(scopeVariable);
                            generator.CastClass(typeof(DeclarativeScope));
                            generator.Call(ReflectionHelpers.DeclarativeScope_Values);
                            generator.LoadInt32(variable.Index);
                            generator.LoadArrayElement(typeof(object));
                        }

                        // The variable was found - no need to search any more parent scopes.
                        break;
                    }
                    else
                    {
                        // The variable was not defined at compile time, but may have been
                        // introduced by an eval() statement.
                        if (optimizationInfo.MethodOptimizationHints.HasEval == true)
                        {
                            // Check the variable exists: if (scope.HasValue(variableName) == true) {
                            if (scopeVariable == null)
                                EmitHelpers.LoadScope(generator);
                            else
                                generator.LoadVariable(scopeVariable);
                            generator.CastClass(typeof(DeclarativeScope));
                            generator.LoadString(this.Name);
                            generator.Call(ReflectionHelpers.Scope_HasValue);
                            var hasValueClause = generator.CreateLabel();
                            generator.BranchIfFalse(hasValueClause);

                            // Load the value of the variable.
                            if (scopeVariable == null)
                                EmitHelpers.LoadScope(generator);
                            else
                                generator.LoadVariable(scopeVariable);
                            generator.CastClass(typeof(DeclarativeScope));
                            generator.LoadString(this.Name);
                            generator.Call(ReflectionHelpers.Scope_GetValue);
                            generator.Branch(endOfGet);

                            // }
                            generator.DefineLabelPosition(hasValueClause);
                        }
                    }
                }
                else
                {
                    if (scope.ParentScope == null)
                    {
//.........这里部分代码省略.........

        /// <summary>
        /// Deletes the reference and pushes <c>true</c> if the delete succeeded, or <c>false</c>
        /// if the delete failed.
        /// </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 void GenerateDelete(ILGenerator generator, OptimizationInfo optimizationInfo)
        {
            // Deleting a variable is not allowed in strict mode.
            if (optimizationInfo.StrictMode == true)
                throw new JavaScriptException(optimizationInfo.Engine, ErrorType.SyntaxError, string.Format("Cannot delete {0} because deleting a variable or argument is not allowed in strict mode", this.Name), optimizationInfo.SourceSpan.StartLine, optimizationInfo.Source.Path, optimizationInfo.FunctionName);

            var endOfDelete = generator.CreateLabel();
            var scope = this.Scope;
            ILLocalVariable scopeVariable = generator.CreateTemporaryVariable(typeof(Scope));
            EmitHelpers.LoadScope(generator);
            generator.StoreVariable(scopeVariable);
            do
            {
                if (scope is DeclarativeScope)
                {
                    var variable = scope.GetDeclaredVariable(this.Name);
                    if (variable != null)
                    {
                        // The variable is known at compile-time.
                        if (variable.Deletable == false)
                        {
                            // The variable cannot be deleted - return false.
                            generator.LoadBoolean(false);
                        }
                        else
                        {
                            // The variable can be deleted (it was declared inside an eval()).
                            // Delete the variable.
                            generator.LoadVariable(scopeVariable);
                            generator.CastClass(typeof(DeclarativeScope));
                            generator.LoadString(this.Name);
                            generator.Call(ReflectionHelpers.Scope_Delete);
                        }
                        break;
                    }
                    else
                    {
                        // The variable was not defined at compile time, but may have been
                        // introduced by an eval() statement.
                        if (optimizationInfo.MethodOptimizationHints.HasEval == true)
                        {
                            // Check the variable exists: if (scope.HasValue(variableName) == true) {
                            generator.LoadVariable(scopeVariable);
                            generator.CastClass(typeof(DeclarativeScope));
                            generator.LoadString(this.Name);
                            generator.Call(ReflectionHelpers.Scope_HasValue);
                            var hasValueClause = generator.CreateLabel();
                            generator.BranchIfFalse(hasValueClause);

                            // If the variable does exist, return true.
                            generator.LoadVariable(scopeVariable);
                            generator.CastClass(typeof(DeclarativeScope));
                            generator.LoadString(this.Name);
                            generator.Call(ReflectionHelpers.Scope_Delete);
                            generator.Branch(endOfDelete);

                            // }
                            generator.DefineLabelPosition(hasValueClause);
                        }
                    }
                }
                else
                {
                    // Check if the property exists by calling scope.ScopeObject.HasProperty(propertyName)
                    generator.LoadVariable(scopeVariable);
                    generator.CastClass(typeof(ObjectScope));
                    generator.Call(ReflectionHelpers.ObjectScope_ScopeObject);
                    generator.Duplicate();
                    generator.LoadString(this.Name);
                    generator.Call(ReflectionHelpers.ObjectInstance_HasProperty);

                    // Jump past the delete if the property doesn't exist.
                    var endOfExistsCheck = generator.CreateLabel();
                    generator.BranchIfFalse(endOfExistsCheck);

                    // Call scope.ScopeObject.Delete(key, false)
                    generator.LoadString(this.Name);
                    generator.LoadBoolean(false);
                    generator.Call(ReflectionHelpers.ObjectInstance_Delete);
                    generator.Branch(endOfDelete);

                    generator.DefineLabelPosition(endOfExistsCheck);
                    generator.Pop();

                    // If the name is not defined, return true.
                    if (scope.ParentScope == null)
                    {
                        generator.LoadBoolean(true);
                    }
                }

                // Try the parent scope.
                if (scope.ParentScope != null && scope.ExistsAtRuntime == true)
                {
//.........这里部分代码省略.........

        /// <summary>
        /// Generates IL for the script.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        /// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
        protected override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
        {
            // Method signature: object FunctionDelegate(Compiler.Scope scope, object thisObject, Library.FunctionInstance functionObject, object[] arguments)

            // Initialize the scope (note: the initial scope for a function is always declarative).
            this.InitialScope.GenerateScopeCreation(generator, optimizationInfo);

            // Verify the scope is correct.
            VerifyScope(generator);

            // In ES3 the "this" value must be an object.  See 10.4.3 in the spec.
            if (this.StrictMode == false && this.MethodOptimizationHints.HasThis == true)
            {
                // if (thisObject == null || thisObject == Null.Value || thisObject == Undefined.Value)
                EmitHelpers.LoadThis(generator);
                generator.LoadNull();
                generator.CompareEqual();
                EmitHelpers.LoadThis(generator);
                EmitHelpers.EmitNull(generator);
                generator.CompareEqual();
                generator.BitwiseOr();
                EmitHelpers.LoadThis(generator);
                EmitHelpers.EmitUndefined(generator);
                generator.CompareEqual();
                generator.BitwiseOr();

                // {
                var startOfFalse = generator.CreateLabel();
                generator.BranchIfFalse(startOfFalse);

                // thisObject = engine.Global;
                EmitHelpers.LoadScriptEngine(generator);
                generator.Call(ReflectionHelpers.ScriptEngine_Global);

                // } else {
                var endOfIf = generator.CreateLabel();
                generator.Branch(endOfIf);
                generator.DefineLabelPosition(startOfFalse);

                // thisObject = TypeConverter.ToObject(thisObject);
                EmitHelpers.LoadThis(generator);
                EmitConversion.ToObject(generator, PrimitiveType.Any);

                // }
                generator.DefineLabelPosition(endOfIf);
                EmitHelpers.StoreThis(generator);
            }

            // Transfer the function name into the scope.
            if (string.IsNullOrEmpty(this.Name) == false &&
                this.ArgumentNames.Contains(this.Name) == false &&
                optimizationInfo.MethodOptimizationHints.HasVariable(this.Name))
            {
                EmitHelpers.LoadFunction(generator);
                var functionName = new NameExpression(this.InitialScope, this.Name);
                functionName.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
            }

            // Transfer the arguments object into the scope.
            if (this.MethodOptimizationHints.HasArguments == true && this.ArgumentNames.Contains("arguments") == false)
            {
                // prototype
                EmitHelpers.LoadScriptEngine(generator);
                generator.Call(ReflectionHelpers.ScriptEngine_Object);
                generator.Call(ReflectionHelpers.FunctionInstance_InstancePrototype);
                // callee
                EmitHelpers.LoadFunction(generator);
                generator.CastClass(typeof(Library.UserDefinedFunction));
                // scope
                EmitHelpers.LoadScope(generator);
                generator.CastClass(typeof(DeclarativeScope));
                // argumentValues
                EmitHelpers.LoadArgumentsArray(generator);
                generator.NewObject(ReflectionHelpers.Arguments_Constructor);
                var arguments = new NameExpression(this.InitialScope, "arguments");
                arguments.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
            }

            // Transfer the argument values into the scope.
            // Note: the arguments array can be smaller than expected.
            if (this.ArgumentNames.Count > 0)
            {
                var endOfArguments = generator.CreateLabel();
                for (int i = 0; i < this.ArgumentNames.Count; i++)
                {
                    // Check if a duplicate argument name exists.
                    bool duplicate = false;
                    for (int j = i + 1; j < this.ArgumentNames.Count; j++)
                        if (this.ArgumentNames[i] == this.ArgumentNames[j])
                        {
                            duplicate = true;
                            break;
                        }
                    if (duplicate == true)
                        continue;
//.........这里部分代码省略.........

        /// <summary>
        /// Generates code that initializes the variable and function declarations.
        /// </summary>
        /// <param name="generator"> The generator to output the CIL to. </param>
        /// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
        internal virtual void GenerateDeclarations(ILGenerator generator, OptimizationInfo optimizationInfo)
        {
            // Initialize the declared variables and functions.
            foreach (var variable in this.variables.Values)
            {
                // When a scope is reused, i.e. with an eval(), do not reinitialize the variables.
                if (variable.Initialized == true)
                    continue;

                if (variable.ValueAtTopOfScope != null)
                {
                    // Emit the initialization code.
                    if (this is ObjectScope)
                    {
                        // Determine the property attributes.
                        var attributes = Library.PropertyAttributes.Enumerable;
                        if (variable.Writable == true)
                            attributes |= Library.PropertyAttributes.Writable;
                        if (variable.Deletable == true)
                            attributes |= Library.PropertyAttributes.Configurable;

                        // bool DefineProperty(string propertyName, PropertyDescriptor descriptor, bool throwOnError)
                        EmitHelpers.LoadScope(generator);
                        generator.CastClass(typeof(ObjectScope));
                        generator.Call(ReflectionHelpers.ObjectScope_ScopeObject);
                        generator.LoadString(variable.Name);
                        variable.ValueAtTopOfScope.GenerateCode(generator, optimizationInfo);
                        EmitConversion.Convert(generator, variable.ValueAtTopOfScope.ResultType, PrimitiveType.Any, optimizationInfo);
                        generator.LoadInt32((int)attributes);
                        generator.NewObject(ReflectionHelpers.PropertyDescriptor_Constructor2);
                        generator.LoadBoolean(false);
                        generator.Call(ReflectionHelpers.ObjectInstance_DefineProperty);
                        generator.Pop();
                    }
                    else
                    {
                        variable.ValueAtTopOfScope.GenerateCode(generator, optimizationInfo);
                        var name = new NameExpression(this, variable.Name);
                        name.GenerateSet(generator, optimizationInfo, variable.ValueAtTopOfScope.ResultType, false);
                    }

                    // Mark the variable as having been initialized.
                    variable.Initialized = true;
                }
            }
        }

        /// <summary>
        /// Generates a method that does type conversion and calls the bound method.
        /// </summary>
        /// <param name="generator"> The ILGenerator used to output the body of the method. </param>
        /// <param name="argumentCount"> The number of arguments that will be passed to the delegate. </param>
        /// <returns> A delegate that does type conversion and calls the method represented by this
        /// object. </returns>
        protected override void GenerateStub(ILGenerator generator, int argumentCount)
        {
            // Here is what we are going to generate.
            //private static object SampleBinder(ScriptEngine engine, object thisObject, object[] arguments)
            //{
            //    // Target function signature: int (bool, int, string, object).
            //    bool param1;
            //    int param2;
            //    string param3;
            //    object param4;
            //    param1 = arguments[0] != 0;
            //    param2 = TypeConverter.ToInt32(arguments[1]);
            //    param3 = TypeConverter.ToString(arguments[2]);
            //    param4 = Undefined.Value;
            //    return thisObject.targetMethod(param1, param2, param3, param4);
            //}

            // Find the target method.
            var binderMethod = this.buckets[Math.Min(argumentCount, this.buckets.Length - 1)];

            // Constrain the number of apparent arguments to within the required bounds.
            int minArgumentCount = binderMethod.RequiredParameterCount;
            int maxArgumentCount = binderMethod.RequiredParameterCount + binderMethod.OptionalParameterCount;
            if (binderMethod.HasParamArray == true)
                maxArgumentCount = int.MaxValue;

            foreach (var argument in binderMethod.GenerateArguments(generator, Math.Min(Math.Max(argumentCount, minArgumentCount), maxArgumentCount)))
            {
                switch (argument.Source)
                {
                    case BinderArgumentSource.ScriptEngine:
                        // Load the "engine" parameter passed by the client.
                        generator.LoadArgument(0);
                        break;

                    case BinderArgumentSource.ThisValue:
                        // Load the "this" parameter passed by the client.
                        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>();
//.........这里部分代码省略.........