Add metadata to each field of an object?

Hi All,
Thanks for your attention.

I'd like to know whether I can add some extra customized structure into current object layout. As far as I know, MiscHeader provides an alternative way to accomplish this, however, it lacks of flexibility and can only add words in the object level. My point is I want to do some profiling to each field of an object, for example, I want to trace when and who did an operation (read/write) to a corresponding field and update it at each access operation site.
class TraceInfo{
        int tid;
        int when;
}
Where can I add this extra information to each field of an object? Can I just add an instance of this structure to the RVMField? Or an alternative way is to add it into TIB?
Will it break the current object layout? How to initialize it correctly?
Thanks very much.

Regards,
--
Xinwei XIE