assembly editing in GDB

assembly editing in GDB

[Vinayak P Risbud]

        Can I run and debug, an assembly program in GDB ?
        If yes, how can I edit and write the assembly program
        in GDB ?

Re: assembly editing in GDB

[Daniel Jacobowitz]

On Tue, Aug 06, 2002 at 11:52:46AM +0530, Vinayak P Risbud wrote:
>         Can I run and debug, an assembly program in GDB ?

Sure.

>         If yes, how can I edit and write the assembly program
>         in GDB ?

You can't.  GDB does not have any support for editing or assembling
code.  You compile the assembly as normal; if you're using the GNU
tools you can use "gcc -g" and it will generally arrange to put
line-number information in the object module.

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

Re: assembly editing in GDB

[William A. Gatliff]

One other thing:  if you do this:

(gdb) display/i $pc

then gdb will actually show the asm instruction it's about to run.  :^)

b.g.


As On Tue, Aug 06, 2002 at 09:11:01AM -0400, Daniel Jacobowitz wrote:
> On Tue, Aug 06, 2002 at 11:52:46AM +0530, Vinayak P Risbud wrote:
> >         Can I run and debug, an assembly program in GDB ?
> 
> Sure.
> 
> >         If yes, how can I edit and write the assembly program
> >         in GDB ?
> 
> You can't.  GDB does not have any support for editing or assembling
> code.  You compile the assembly as normal; if you're using the GNU
> tools you can use "gcc -g" and it will generally arrange to put
> line-number information in the object module.
> 
> -- 
> Daniel Jacobowitz                           Carnegie Mellon University
> MontaVista Software                         Debian GNU/Linux Developer

-- 
Bill Gatliff
bgat@billgatliff.com

Re: assembly editing in GDB

[Carlos O'Donell]

On Tue, Aug 06, 2002 at 11:52:46AM +0530, Vinayak P Risbud wrote:
>         Can I run and debug, an assembly program in GDB ?
>         If yes, how can I edit and write the assembly program
>         in GDB ?

GDB is a debugger not an editor :}

Assembly programs can definately be debug'd in gdb.
Just start it up as you would with any other program,
and start putting break points at addresses instead of
source lines.

# gdb hello
> break main
> r
...
> disassemble

And if you want to _edit_ it while running you need to
use 'set write on' (before loading) and then 'file hello'.

Check out all the variations of break, since you will have
to feed it addresses for code that doesn't have debug info.

I really really really recommend reading all the material
at: http://sources.redhat.com/gdb/documentation/

c.