New object file parser?

New object file parser?

[Dan Towner]

Hi all,

I am porting gdb to a new processor architecture (embedded
multi-processor DSP). Currently, although we use gcc as our compiler, we
have a proprietary assembler and linker, which generate non-standard
object and executable files. Now, faced with the task of getting the
symbol table information from the object file through to gdb, is it
easier to:

 1) Write a new parser for BFD.

or

 2) Write a converter which generates a standard object file format from
our proprietary format.

Whichever route I take, which object file would be the easier to deal
with? From what I have seen, I think that a.out would be the best, but
is there anything simpler? 

Dan,

=============================================================================
Daniel Towner
picoChip Designs Ltd., Riverside Buildings, 108, Walcot Street, BATH,
BA1 5BG
dant@picochip.com
07786 702589

Re: New object file parser?

[Jim Blandy]

Dan Towner <dant@picochip.com> writes:
> I am porting gdb to a new processor architecture (embedded
> multi-processor DSP). Currently, although we use gcc as our compiler, we
> have a proprietary assembler and linker, which generate non-standard
> object and executable files. Now, faced with the task of getting the
> symbol table information from the object file through to gdb, is it
> easier to:
> 
>  1) Write a new parser for BFD.
> 
> or
> 
>  2) Write a converter which generates a standard object file format from
> our proprietary format.

Well, you've made your bed...   :)

> Whichever route I take, which object file would be the easier to deal
> with? From what I have seen, I think that a.out would be the best, but
> is there anything simpler? 

Well, there's S-records.  I don't know if they can carry symbol
information, though.  I think not.

If you need a symbol table, I'd say a.out is probably the simplest one
there is.  You can probably find documentation for a.out in the SunOS
4 man pages, or perhaps somewhere on the Web.

The next question is, what debugging format do you use?  Converting
debugging info from the proprietary format to STABS or Dwarf is going
to be the hard part, I'd bet.

Re: New object file parser?

[Dan Towner]

Jim Blandy wrote:

> Well, there's S-records.  I don't know if they can carry symbol
> information, though.  I think not.
> 
> If you need a symbol table, I'd say a.out is probably the simplest one
> there is.  You can probably find documentation for a.out in the SunOS
> 4 man pages, or perhaps somewhere on the Web.
> 
> The next question is, what debugging format do you use?  Converting
> debugging info from the proprietary format to STABS or Dwarf is going
> to be the hard part, I'd bet.

It already uses STABS, it just stores it in a slightly odd way.

Dan.

=============================================================================
Daniel Towner
picoChip Designs Ltd., Riverside Buildings, 108, Walcot Street, BATH,
BA1 5BG
dant@picochip.com
07786 702589

Re: New object file parser?

[Daniel Jacobowitz]

On Fri, Jul 12, 2002 at 05:56:47PM +0100, Dan Towner wrote:
> Jim Blandy wrote:
> 
> > Well, there's S-records.  I don't know if they can carry symbol
> > information, though.  I think not.
> > 
> > If you need a symbol table, I'd say a.out is probably the simplest one
> > there is.  You can probably find documentation for a.out in the SunOS
> > 4 man pages, or perhaps somewhere on the Web.
> > 
> > The next question is, what debugging format do you use?  Converting
> > debugging info from the proprietary format to STABS or Dwarf is going
> > to be the hard part, I'd bet.
> 
> It already uses STABS, it just stores it in a slightly odd way.

In all honesty, although it is slightly more effort, I recommend using
ELF instead.  If you aren't trying to be terribly complicated with it,
then it's fairly straightforward; and UNLIKE a.out, it is very well
documented.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer