//
// Return container with awaiter definition. It never returns null
// but all container member can be null for easier error reporting
//
public AwaiterDefinition GetAwaiter(TypeSpec type)
{
AwaiterDefinition awaiter;
if (awaiters.TryGetValue(type, out awaiter))
{
return(awaiter);
}
awaiter = new AwaiterDefinition();
//
// Predefined: bool IsCompleted { get; }
//
awaiter.IsCompleted = MemberCache.FindMember(type, MemberFilter.Property("IsCompleted", Compiler.BuiltinTypes.Bool),
BindingRestriction.InstanceOnly) as PropertySpec;
//
// Predefined: GetResult ()
//
// The method return type is also result type of await expression
//
awaiter.GetResult = MemberCache.FindMember(type, MemberFilter.Method("GetResult", 0,
ParametersCompiled.EmptyReadOnlyParameters, null),
BindingRestriction.InstanceOnly) as MethodSpec;
//
// Predefined: INotifyCompletion.OnCompleted (System.Action)
//
var nc = PredefinedTypes.INotifyCompletion;
awaiter.INotifyCompletion = !nc.Define() || type.ImplementsInterface(nc.TypeSpec, false);
awaiters.Add(type, awaiter);
return(awaiter);
}