protected Shape transitionWithNewField(Shape oldShape, Object value) {
// This duplicates quite a bit of DynamicObject.define(), but should be fixed in Truffle soon.
final Property oldProperty = oldShape.getProperty(name);
if (oldProperty != null) {
if (oldProperty.getFlags() == 0 && oldProperty.getLocation().canSet(null, value)) {
return oldShape; // already the right shape
} else {
DynamicObject copy = oldShape.getLayout().newInstance(oldShape);
copy.define(name, value, 0);
return copy.getShape();
}
} else {
final Location location =
oldShape
.allocator()
.locationForValue(
value, EnumSet.of(LocationModifier.Final, LocationModifier.NonNull));
final Property newProperty = Property.create(name, location, 0);
return oldShape.addProperty(newProperty);
}
}
