public static ArgumentsInstance CreateArgumentsObject(Engine engine, FunctionInstance func, string[] names, JsValue[] args, EnvironmentRecord env, bool strict)
{
var len = args.Length;
var obj = new ArgumentsInstance(engine);
obj.Prototype = engine.Object.PrototypeObject;
obj.Extensible = true;
obj.FastAddProperty("length", len, true, false, true);
obj.Strict = strict;
var map = engine.Object.Construct(Arguments.Empty);
var mappedNamed = new List<string>();
var indx = 0;
while (indx <= len - 1)
{
var indxStr = TypeConverter.ToString(indx);
var val = args[indx];
obj.FastAddProperty(indxStr, val, true, true, true);
if (indx < names.Length)
{
var name = names[indx];
if (!strict && !mappedNamed.Contains(name))
{
mappedNamed.Add(name);
Func<JsValue, JsValue> g = n => env.GetBindingValue(name, false);
var p = new Action<JsValue, JsValue>((n, o) => env.SetMutableBinding(name, o, true));
map.DefineOwnProperty(indxStr, new ClrAccessDescriptor(engine, g, p) { Configurable = true }, false);
}
}
indx++;
}
// step 12
if (mappedNamed.Count > 0)
{
obj.ParameterMap = map;
}
// step 13
if (!strict)
{
obj.FastAddProperty("callee",func, true, false, true);
}
// step 14
else
{
var thrower = engine.Function.ThrowTypeError;
obj.DefineOwnProperty("caller", new PropertyDescriptor(get: thrower, set: thrower, enumerable:false, configurable:false), false);
obj.DefineOwnProperty("callee", new PropertyDescriptor(get: thrower, set: thrower, enumerable: false, configurable: false), false);
}
return obj;
}
// http://www.ecma-international.org/ecma-262/5.1/#sec-10.5
public void DeclarationBindingInstantiation(DeclarationBindingType declarationBindingType, IList<FunctionDeclaration> functionDeclarations, IList<VariableDeclaration> variableDeclarations, FunctionInstance functionInstance, JsValue[] arguments)
{
var env = ExecutionContext.VariableEnvironment.Record;
bool configurableBindings = declarationBindingType == DeclarationBindingType.EvalCode;
var strict = StrictModeScope.IsStrictModeCode;
if (declarationBindingType == DeclarationBindingType.FunctionCode)
{
var argCount = arguments.Length;
var n = 0;
foreach (var argName in functionInstance.FormalParameters)
{
n++;
var v = n > argCount ? Undefined.Instance : arguments[n - 1];
var argAlreadyDeclared = env.HasBinding(argName);
if (!argAlreadyDeclared)
{
env.CreateMutableBinding(argName);
}
env.SetMutableBinding(argName, v, strict);
}
}
foreach (var f in functionDeclarations)
{
var fn = f.Id.Name;
var fo = Function.CreateFunctionObject(f);
var funcAlreadyDeclared = env.HasBinding(fn);
if (!funcAlreadyDeclared)
{
env.CreateMutableBinding(fn, configurableBindings);
}
else
{
if (env == GlobalEnvironment.Record)
{
var go = Global;
var existingProp = go.GetProperty(fn);
if (existingProp.Configurable.Value.AsBoolean())
{
go.DefineOwnProperty(fn,
new PropertyDescriptor(
value: Undefined.Instance,
writable: true,
enumerable: true,
configurable: configurableBindings
), true);
}
else
{
if (existingProp.IsAccessorDescriptor() || (!existingProp.Enumerable.Value.AsBoolean()))
{
throw new JavaScriptException(TypeError);
}
}
}
}
env.SetMutableBinding(fn, fo, strict);
}
var argumentsAlreadyDeclared = env.HasBinding("arguments");
if (declarationBindingType == DeclarationBindingType.FunctionCode && !argumentsAlreadyDeclared)
{
var argsObj = ArgumentsInstance.CreateArgumentsObject(this, functionInstance, functionInstance.FormalParameters, arguments, env, strict);
if (strict)
{
var declEnv = env as DeclarativeEnvironmentRecord;
if (declEnv == null)
{
throw new ArgumentException();
}
declEnv.CreateImmutableBinding("arguments");
declEnv.InitializeImmutableBinding("arguments", argsObj);
}
else
{
env.CreateMutableBinding("arguments");
env.SetMutableBinding("arguments", argsObj, false);
}
}
// process all variable declarations in the current parser scope
foreach (var d in variableDeclarations.SelectMany(x => x.Declarations))
{
var dn = d.Id.Name;
var varAlreadyDeclared = env.HasBinding(dn);
if (!varAlreadyDeclared)
{
env.CreateMutableBinding(dn, configurableBindings);
env.SetMutableBinding(dn, Undefined.Instance, strict);
}
}
}
