New 'as' port: GPL requirements?

[DJ Delorie]

> I know GPL-legalese is possibly the dullest thing on the planet, but I 
> can't start on this port without a definitive answer, so I'd  appreciate 
> some feedback on this...

gnu.misc.discuss is the right place for non-gas-specific questions, too.

NOBODY on this mailing list is the copyright holder, nor can anyone
here legally answer your question.  You'd need to contact the FSF
directly.  But given that IANAL, I'll add my comments anyway...

> Summary: I want to modify an existing GPL-ed program (gas) such that it 
> makes calls to proprietary library 'A'.

I think the key thing is this:

> > But if the semantics of the communication are intimate enough,

If you've modified the assembler so that it cannot function without
the proprietary code, you've created a proprietary assembler.  In this
case, you're using a proprietary interface for which there is no free
replacement implementation, so IMHO the semantically tight coupling
between gas and this library is more significant than the mechanism of
the coupling wrt whether it's a derived work or a mere aggregate.

Besides, you can't build a cross assembler that way ;-)

> The library is an independent entity that is unrelated to the
> calling program.

*Was* unrelated.  You related them when you linked them together.  The
direction of the relationship is mostly irrelevent.

> We've all written code that calls, for example, 'fopen' - does 
> that mean that we've all extended 'fopen'?

Actually, glibc and the GPL have specific exceptions for that kind of
use, so YES the GPL would have applied otherwise (such as your case),
were it not for the exceptions.