internal compiler error for -fall-virtual for 2.95.2 FOLLOW-ON

[Martin v. Loewis]

> I've managed to find a workaround that works, and one that *this*
> time will work from here on out.  Moreover, I hope that the
> workaround will yield insight into the exact nature of the problem.

Thanks again for your bug report. As I suspected from the beginning,
this is a bug in your code, not in g++.

In C++, all non-pure non-inline virtual methods must be implemented,
whether they are actually called or not. This requirement allows the
compiler to use the implementation of the first non-pure non-inline
virtual method as a guidance for emitting virtual tables and type_info
functions. 

Now, if you look at Attribute.h, you'll see that the first such
function is

      virtual void print( ostream &, Atom const * ) const;

Also, you'll notice that this is not implemented in Attribute.cpp;
this is your error.

Regards,
Martin