/// <summary>
/// Calls the given method virtually. Pops its arguments in reverse order (left-most deepest in the stack), and pushes the return value if it is non-void.
///
/// The `this` reference should appear before any arguments (deepest in the stack).
///
/// The method invoked at runtime is determined by the type of the `this` reference.
///
/// If the method invoked shouldn't vary (or if the method is static), use Call instead.
/// </summary>
public Emit <DelegateType> CallVirtual(MethodInfo method, Type constrained = null, Type[] arglist = null)
{
if (method == null)
{
throw new ArgumentNullException("method");
}
if (method.IsStatic)
{
throw new ArgumentException("Only non-static methods can be called using CallVirtual, found " + method);
}
if (HasFlag(method.CallingConvention, CallingConventions.VarArgs) && !HasFlag(method.CallingConvention, CallingConventions.Standard))
{
if (arglist == null)
{
throw new InvalidOperationException("When calling a VarArgs method, arglist must be set");
}
}
var expectedParams = ((LinqArray <ParameterInfo>)method.GetParameters()).Select(s => TypeOnStack.Get(s.ParameterType)).ToList();
var declaring = method.DeclaringType;
if (TypeHelpers.IsValueType(declaring))
{
declaring = declaring.MakePointerType();
}
// "this" parameter
expectedParams.Insert(0, TypeOnStack.Get(declaring));
if (arglist != null)
{
expectedParams.AddRange(LinqAlternative.Select(arglist, t => TypeOnStack.Get(t)));
}
var resultType = method.ReturnType == typeof(void) ? null : TypeOnStack.Get(method.ReturnType);
// Shove the constrained prefix in if it's supplied
if (constrained != null)
{
UpdateState(OpCodes.Constrained, constrained, Wrap(StackTransition.None(), "CallVirtual"));
}
IEnumerable <StackTransition> transitions;
if (resultType != null)
{
transitions =
new[]
{
new StackTransition(expectedParams.Reverse().AsEnumerable(), new [] { resultType })
};
}
else
{
transitions =
new[]
{
new StackTransition(expectedParams.Reverse().AsEnumerable(), new TypeOnStack[0])
};
}
UpdateState(OpCodes.Callvirt, method, ((LinqArray <ParameterInfo>)method.GetParameters()).Select(s => s.ParameterType).AsEnumerable(), Wrap(transitions, "CallVirtual"), arglist: arglist);
return(this);
}
