Offset and Bit Mask for Bit Fields?

[Andrew Haley]

Dimitry Golubovsky writes:
 > 
 > If one wants to automatically determine offset of a regular field in a
 > C structure, one uses `offsetof'
 > 
 > According to the documentation, 
 > 
 > ==============
 > This macro (offsetof) won't work if member is a bit field; you get an
 > error from the C compiler in that case.
 > ==============

Yes, because it's not addressable.

 > Do there exist any means in gcc to measure offsets (of enclosing
 > integer field) and bit mask for bit fields?

No.

 > If not, any chance to add them in the future?

I doubt it.  We're very reluctant to add new language extensions to C,
and this one would be very problematic.

Andrew.