/// <summary>
/// Returns true if this type has a common representation in both managed and unmanaged memory
/// and does not require special handling by the interop marshaler.
/// </summary>
public static bool IsBlittableType(TypeDesc type)
{
if (!type.IsDefType)
{
return(false);
}
DefType baseType = type.BaseType;
bool hasNonTrivialParent = baseType != null &&
!baseType.IsWellKnownType(WellKnownType.Object) &&
!baseType.IsWellKnownType(WellKnownType.ValueType);
// Type is blittable only if parent is also blittable and is not empty.
if (hasNonTrivialParent && (!IsBlittableType(baseType) || baseType.IsZeroSizedReferenceType))
{
return(false);
}
var mdType = (MetadataType)type;
if (!mdType.IsSequentialLayout && !mdType.IsExplicitLayout)
{
return(false);
}
foreach (FieldDesc field in type.GetFields())
{
if (field.IsStatic)
{
continue;
}
MarshallerKind marshallerKind = MarshalHelpers.GetMarshallerKind(
field.FieldType,
parameterIndex: null,
customModifierData: null,
field.GetMarshalAsDescriptor(),
isReturn: false,
isAnsi: mdType.PInvokeStringFormat == PInvokeStringFormat.AnsiClass,
MarshallerType.Field,
elementMarshallerKind: out var _);
if (marshallerKind != MarshallerKind.Enum &&
marshallerKind != MarshallerKind.BlittableValue &&
marshallerKind != MarshallerKind.BlittableStruct &&
marshallerKind != MarshallerKind.UnicodeChar)
{
return(false);
}
}
return(true);
}