internal static void EmitConvertToType(this ILGenerator il, Type typeFrom, Type typeTo, bool isChecked)
{
if (TypeUtils.AreEquivalent(typeFrom, typeTo))
{
return;
}
if (typeFrom == typeof(void) || typeTo == typeof(void))
{
throw ContractUtils.Unreachable;
}
bool isTypeFromNullable = TypeUtils.IsNullableType(typeFrom);
bool isTypeToNullable = TypeUtils.IsNullableType(typeTo);
Type nnExprType = TypeUtils.GetNonNullableType(typeFrom);
Type nnType = TypeUtils.GetNonNullableType(typeTo);
if (typeFrom.IsInterface || // interface cast
typeTo.IsInterface ||
typeFrom == typeof(object) || // boxing cast
typeTo == typeof(object))
{
il.EmitCastToType(typeFrom, typeTo);
}
else if (isTypeFromNullable || isTypeToNullable)
{
il.EmitNullableConversion(typeFrom, typeTo, isChecked);
}
else if (!(TypeUtils.IsConvertible(typeFrom) && TypeUtils.IsConvertible(typeTo)) // primitive runtime conversion
&&
(nnExprType.IsAssignableFrom(nnType) || // down cast
nnType.IsAssignableFrom(nnExprType))) // up cast
{
il.EmitCastToType(typeFrom, typeTo);
}
else if (typeFrom.IsArray && typeTo.IsArray)
{
// See DevDiv Bugs #94657.
il.EmitCastToType(typeFrom, typeTo);
}
else
{
il.EmitNumericConversion(typeFrom, typeTo, isChecked);
}
}
