/// <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)
{
// Check for the correct number of arguments.
if (argumentCount != 0)
{
EmitHelpers.EmitThrow(generator, "TypeError", "Wrong number of arguments");
EmitHelpers.EmitDefaultValue(generator, PrimitiveType.Any);
generator.Complete();
return;
}
if (this.Field.IsStatic == false)
{
generator.LoadArgument(1);
ClrBinder.EmitConversionToType(generator, this.Field.DeclaringType, true);
}
generator.LoadField(this.Field);
ClrBinder.EmitConversionToObject(generator, this.Field.FieldType);
generator.Complete();
}
/// <summary>
/// Gets an enumerable list of argument objects, equal in size to
/// <paramref name="argumentCount"/> while generating code to prepare those arguments for
/// a method call.
/// </summary>
/// <param name="argumentCount"> The number of arguments to return. </param>
/// <param name="generator"> The IL generator used to create an array if the method has a
/// ParamArray parameter. </param>
/// <returns> An enumerable list of argument objects. </returns>
public IEnumerable <BinderArgument> GenerateArguments(ILGenerator generator, int argumentCount)
{
if (generator == null)
{
throw new ArgumentNullException("generator");
}
int paramArrayIndex = 0;
foreach (var argument in this.GetArguments(argumentCount))
{
if (argument.IsParamArrayArgument)
{
if (paramArrayIndex == 0)
{
// This is the start of the ParamArray arguments.
// Create an array.
int paramArraySize = Math.Max(0, argumentCount - this.OptionalParameterCount - this.RequiredParameterCount);
generator.LoadInt32(paramArraySize);
generator.NewArray(argument.Type);
}
// Load the array and index.
generator.Duplicate();
generator.LoadInt32(paramArrayIndex++);
}
// Yield will have the side effect of generating a value.
yield return(argument);
if (argument.IsParamArrayArgument)
{
// Store the value in the ParamArray array.
generator.StoreArrayElement(argument.Type);
}
}
// Populate any missing optional arguments with the default value.
if (this.RequiredParameterCount + this.OptionalParameterCount - argumentCount > 0)
{
var parameters = this.GetParameters();
for (int i = 0; i < this.RequiredParameterCount + this.OptionalParameterCount - argumentCount; i++)
{
var optionalParameter = parameters[argumentCount + i];
if ((optionalParameter.Attributes & ParameterAttributes.HasDefault) == ParameterAttributes.HasDefault)
{
// Emit the default value.
EmitHelpers.EmitValue(generator, new BinderArgument(optionalParameter, 0).DefaultValue);
}
else
{
// Emit default(T).
EmitHelpers.EmitDefaultValue(generator, optionalParameter.ParameterType);
}
}
}
// Create an empty array if a ParamArray argument exists but no arguments were provided.
if (this.HasParamArray && paramArrayIndex == 0)
{
// Create an array.
generator.LoadInt32(0);
generator.NewArray(this.ParamArrayElementType);
}
}
/// <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)
{
// Determine the methods that have the correct number of arguments.
var candidateMethods = this.m_targetMethods
.Where(candidateMethod => candidateMethod.IsArgumentCountCompatible(argumentCount))
.ToList();
// Zero candidates means no overload had the correct number of arguments.
if (candidateMethods.Count == 0)
{
EmitHelpers.EmitThrow(generator, "TypeError", string.Format("No overload for method '{0}' takes {1} arguments", this.Name, argumentCount));
EmitHelpers.EmitDefaultValue(generator, PrimitiveType.Any);
generator.Complete();
return;
}
// Select the method to call at run time.
generator.LoadInt32(candidateMethods.Count);
generator.NewArray(typeof(RuntimeMethodHandle));
for (int i = 0; i < candidateMethods.Count; i++)
{
generator.Duplicate();
generator.LoadInt32(i);
generator.LoadToken(candidateMethods[i]);
generator.StoreArrayElement(typeof(RuntimeMethodHandle));
}
generator.LoadArgument(0);
generator.LoadArgument(1);
generator.LoadArgument(2);
generator.Call(ReflectionHelpers.BinderUtilities_ResolveOverloads.Value);
var endOfMethod = generator.CreateLabel();
for (int i = 0; i < candidateMethods.Count; i++)
{
// Check if this is the selected method.
ILLabel endOfIf = null;
if (i < candidateMethods.Count - 1)
{
generator.Duplicate();
generator.LoadInt32(i);
endOfIf = generator.CreateLabel();
generator.BranchIfNotEqual(endOfIf);
}
generator.Pop();
var targetMethod = candidateMethods[i];
// Convert the arguments.
foreach (var argument in targetMethod.GenerateArguments(generator, argumentCount))
{
// Load the input parameter value.
switch (argument.Source)
{
case BinderArgumentSource.ScriptEngine:
generator.LoadArgument(0);
break;
case BinderArgumentSource.ThisValue:
generator.LoadArgument(1);
break;
case BinderArgumentSource.InputParameter:
generator.LoadArgument(2);
generator.LoadInt32(argument.InputParameterIndex);
generator.LoadArrayElement(typeof(object));
break;
}
// Convert to the target type.
EmitConversionToType(generator, argument.Type, argument.Source == BinderArgumentSource.ThisValue);
}
// Call the target method.
targetMethod.GenerateCall(generator);
// Convert the return value.
if (targetMethod.ReturnType == typeof(void))
{
EmitHelpers.EmitUndefined(generator);
}
else
{
EmitConversionToObject(generator, targetMethod.ReturnType);
}
// Branch to the end of the method if this was the selected method.
if (endOfIf != null)
{
generator.Branch(endOfMethod);
generator.DefineLabelPosition(endOfIf);
}
}
generator.DefineLabelPosition(endOfMethod);
generator.Complete();
}