Re: Petr Sorfa's Dwarf 2 changes

[Jim Blandy <jimb@redhat.com>]

Daniel Jacobowitz <drow@mvista.com> writes:
> On Mon, Nov 04, 2002 at 03:06:21PM -0500, Jim Blandy wrote:
> > 
> > Andrew Cagney <ac131313@redhat.com> writes:
> > > > I'm undertaking some related work in dwarf2read.c which will almost
> > > > certainly conflict with Caldera's changes, and I'd like to see where
> > > > you guys ended up.
> > > 
> > > Care to expand?
> > 
> > Sure --- I'm trying to put together a patch to support
> > inter-compilation unit die references, which is (the hardest?) part of
> > supporting Dwarf 2 compression.
> > 
> > I think the changes are going to be pretty widespread.
> > 
> > At the moment, dwarf2read.c has a number of global variables that
> > describe per-compilation-unit things.  These get set as we do the
> > psymtab scan, stashed in each psymtab we create, and then restored
> > each time we convert a psymtab to a symtab.  If we're going to handle
> > inter-CU references, we're going to be dealing with more than one CU
> > at a time, so that's not going to be sufficient any more --- which CU
> > you need depends on which die you're looking at.
> > 
> > I'd like to change GDB to have a per-objfile Dwarf-specific structure
> > (like struct dbx_symfile_info for STABS), and per-CU Dwarf-specific
> > structures.  These would be passed as arguments amongst the
> > dwarf2read.c functions as appropriate.  Furthermore, each die might
> > need to have a pointer to the CU that owns it.
> > 
> > Those are pretty pervasive changes, but I think the folks who have
> > worked in dwarf2read.c will agree that they're the right way to go.
> > When I've gotten something working on the branch I'll have more
> > perspective on what's really needed.
> 
> Not only will they agree, I believe Petr and John had already finished
> doing this.  Doubtless there's still some room for improvement, but the
> functionality is there...  John, do you have that merged dwarf2read
> available?

Yeah, not to diss that at all: I should have also explained that I'm
hoping to steal as much of that work as I can.  (Thus the request that
started this thread.)