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