GDB Scripting

GDB Scripting

[Robert Graulich]

Hi all,

is it possible, to store the result of a gdb command like 'frame' in a variable?
I like to write someting like

  define hook-stop
    set $FRAME=frame
    if $FRAME=="main"
      ...
    else
      ...
    end
  end

How to do that?

Robert

Re: GDB Scripting

[Fernando Nasser]

Robert Graulich wrote:
> 
> Hi all,
> 
> is it possible, to store the result of a gdb command like 'frame' in a variable?
> I like to write someting like
> 
>   define hook-stop
>     set $FRAME=frame
>     if $FRAME=="main"
>       ...
>     else
>       ...
>     end
>   end
> 
> How to do that?
> 

Unfortunately the "frame" command does not set any convenience variable
automatically (which is the only way to obtain data from a GDB command 
execution).  So, the way to do this is:

Set a breakpoint at main.
Use the "commands" command and add
print $main_fp=$<reg>
continue

where <reg> is the FP register in your architecture.


Then just make your if compare the $<reg> at the
point you've stopped with $main_fp


I hope this helps.

Regards,
Fernando



-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9