private void CheckPossibleValueInUnion(object value, ICustomAttributeProvider provider)
{
string switchExpr;
if (provider == null || !MarshalingDescriptor.TryGetAttribute <string>(
provider, typeof(SwitchAttribute), "expr",
out switchExpr))
{
throw new InvalidOperationException(String.Format(
CultureInfo.InvariantCulture,
"cannot find switch attribute for union '{0}'",
value.GetType().Name));
}
Type type = value.GetType();
var fieldsToCheck = new List <FieldInfo>();
var defaultFields = new List <FieldInfo>();
foreach (var field in type.GetFields())
{
string caseExpr;
if (MarshalingDescriptor.TryGetAttribute <string>(field,
typeof(CaseAttribute), "expr", out caseExpr))
{
IList <int?> caseValues = marshaler.EvaluateConstant(caseExpr);
int switchValue = marshaler.Evaluate(switchExpr);
if (caseValues.Contains(switchValue))
{
fieldsToCheck.Add(field);
}
}
else if (field.GetCustomAttributes(typeof(CaseDefaultAttribute), false).Length != 0)
{
defaultFields.Add(field);
}
}
if (fieldsToCheck.Count == 0)
{
fieldsToCheck.AddRange(defaultFields);
}
foreach (var field in fieldsToCheck)
{
object fieldValue = field.GetValue(value);
if (IsStruct(field.GetType()))
{
CheckPossibleValue(fieldValue, field);
}
else if (HasPossibleValue(field))
{
CheckFieldValue(fieldValue, field);
}
}
}
