/// <summary>
/// ICastable is a special interface whose two methods are not invoked using regular interface dispatch.
/// Instead, their VTable slots are recorded on the EEType of an object implementing ICastable and are
/// called directly.
/// </summary>
void ComputeICastableVirtualMethodSlots(NodeFactory factory)
{
// TODO: This method is untested (we don't support interfaces yet)
if (_type.IsInterface)
{
return;
}
foreach (DefType itf in _type.RuntimeInterfaces)
{
if (itf == factory.ICastableInterface)
{
var isInstMethod = itf.GetMethod("IsInstanceOfInterface", null);
var getImplTypeMethod = itf.GetMethod("GetImplType", null);
Debug.Assert(isInstMethod != null && getImplTypeMethod != null);
int isInstMethodSlot = VirtualMethodSlotHelper.GetVirtualMethodSlot(factory, isInstMethod);
int getImplTypeMethodSlot = VirtualMethodSlotHelper.GetVirtualMethodSlot(factory, getImplTypeMethod);
if (isInstMethodSlot != -1 || getImplTypeMethodSlot != -1)
{
var rareFlags = _optionalFieldsBuilder.GetFieldValue(EETypeOptionalFieldsElement.RareFlags, 0);
rareFlags |= (uint)EETypeRareFlags.ICastableFlag;
_optionalFieldsBuilder.SetFieldValue(EETypeOptionalFieldsElement.RareFlags, rareFlags);
}
if (isInstMethodSlot != -1)
{
_optionalFieldsBuilder.SetFieldValue(EETypeOptionalFieldsElement.ICastableIsInstSlot, (uint)isInstMethodSlot);
}
if (getImplTypeMethodSlot != -1)
{
_optionalFieldsBuilder.SetFieldValue(EETypeOptionalFieldsElement.ICastableGetImplTypeSlot, (uint)getImplTypeMethodSlot);
}
}
}
}
