/// <summary>
/// Emits the IL for this method. Adds a backing static method to which the expression is compiled,
/// then calls that method with appropriate arguments
/// </summary>
/// <param name="il">IL generator for the current method</param>
/// <param name="sourceField">Field representing the source component</param>
/// <param name="typeBeingBuilt">The type being built</param>
internal override void Emit(ILGenerator il, FieldBuilder sourceField, TypeSpecifier typeBeingBuilt)
{
var pTypes = _expr.Parameters.Select(p => p.Type).ToArray();
var nestedClass = typeBeingBuilt.CreateDisplayClass();
var lambda = nestedClass.TypeBuilder.DefineMethod(nestedClass.GetMethodName(_name),
MethodAttributes.Static | MethodAttributes.HideBySig | MethodAttributes.Public,
_expr.ReturnType,
pTypes);
// We'd really like to compile this straight into our method,
// but `LambdaExpression.CompileToMethod` only takes static methods,
// so the next best thing is to use this attribute to tell the JITter
// that it should be inlined.
lambda.SetCustomAttribute(new CustomAttributeBuilder(
typeof(MethodImplAttribute).GetConstructor(new Type[] { typeof(MethodImplOptions) }),
new object[1] {
MethodImplOptions.AggressiveInlining
}));
_expr.CompileToMethod(lambda);
foreach (var p in _params)
{
p.Emit(il, sourceField, typeBeingBuilt.TypeBuilder);
}
il.Emit(OpCodes.Call, lambda);
il.Emit(OpCodes.Ret);
}
/// <summary>
/// Emits the IL for this method
/// </summary>
/// <param name="il">IL Generator</param>
/// <param name="sourceField">The field containing the source component</param>
/// <param name="typeBeingBuilt">The type being built</param>
internal override void Emit(ILGenerator il, FieldBuilder sourceField, TypeSpecifier typeBeingBuilt)
{
var nestedType = typeBeingBuilt.CreateDisplayClass();
var backingField = nestedType.TypeBuilder.DefineField(nestedType.GetInvokeName(_name),
_invoke.GetType(),
FieldAttributes.Static | FieldAttributes.Public);
typeBeingBuilt.RunAfterCreation(() =>
{
backingField.SafeSetValue(null, _invoke);
});
il.Emit(OpCodes.Ldsfld, backingField);
foreach (var p in _params)
{
p.Emit(il, sourceField, typeBeingBuilt.TypeBuilder);
}
il.Emit(OpCodes.Callvirt, _invoke.GetType().GetMethod("Invoke"));
il.Emit(OpCodes.Ret);
}