How does the GNU runtime encode method signatures?

[Ziemowit Laski]

I've recently cleaned up the NeXT method signature encoding (by the 
compiler)
quite a bit in Apple's tree, to a point where it is no longer necessary
to do the awkward handshake with the back-end via 
hack_method_prototype() in
order to determine the offsets and sizes of parameters.  I've also been 
told
(by Apple's ObjC runtime maintainers) is that the method encodings 
generated
by the compiler have, historically speaking, been so profoundly broken 
that
the runtime ignored them and computed its own. :-)

So, what's the situation like on the GNU side of things?  Does the GNU 
runtime
still rely on what the compiler generates?  Does the GNU method 
encoding have
a spec? :-)  I'm asking because I'd like to yank out 
hack_method_prototype()
and generally simplify the encoding machinery in objc-act.c, but am not 
sure
if it is safe to do so.

Thanks.  (And yes, I'd definitely like to put Apple's ObjC fixes, 
including
method encodings, into the FSF. :-) )

--Zem
--------------------------------------------------------------
Ziemowit Laski                 1 Infinite Loop, MS 301-2K
Mac OS X Compiler Group        Cupertino, CA USA  95014-2083
Apple Computer, Inc.           +1.408.974.6229  Fax .5477