Re: dwarf2-frame.c question for maintainers

["Martin M. Hunt" <hunt at redhat dot com>]

On Wed, 2004-07-14 at 10:26, Andrew Cagney wrote:
> > I'm working on some dwarf2 fixes with kevinb.  In
> > dwarf2_build_frame_info(), Kevin added 
> > +unit.signed_addr_p = bfd_get_sign_extend_vma (unit.abfd);
> > 
> > This is useful for fixing several bugs where addresses needed to be
> > sign-extended.  However, I found that read_reg() also needs to
> > sign-extend its result.  Passing a pointer to the CU all the way down to
> > read_reg doesn't seem practical.
> > 
> > I don't have any understanding of the overall structure of this code or
> > where it is going. I can see several possibilities, including the
> > obvious one; using a global. So how do I solve this to get the patch
> > accepted?
> 
> (The global is out :-)
> 
> How come extract_typed_address, in read_reg, doesn't sign extend?

I should have explained that. It does.  However extract_typed_address is
incorrect because it makes the invalid assumption that sizeof(address)
== sizeof(register).  So that has to go and be replaced with something
like
extract_signed_integer (buf, register_size (current_gdbarch, regnum));

> The MIPS (I'm assuming this is for the MIPS) has the dogma that _all_ 
> addresses (a.k.a. CORE_ADDRs) are _always_ sign extended.  If you see a 
> non sign-extended address in the wild, try tracing it back to where it 
> was created.
> 
> Andrew
-- 
Martin M. Hunt <hunt@redhat.com>
Red Hat Inc.