Re: making stabs visible to gdb

[Nick Clifton <nickc@redhat.com>]

Hi Tavis,

> Hello, I have a stripped binary I don't have the source for that I would
> like to debug in gdb. I thought writing some .stabs statements in gas
> would be a nice easy way to record the symbols I know about, like this:
> 
> .equ N_FUN, 0x24
> .equ N_PSYM, 0xa0
> .stabs "example:f-11", N_FUN, 0, 0, 0x8005bba
> .stabs "foo:p*-8", N_PSYM, 0, 0, 8
> .stabs "bar:p-10", N_PSYM, 0, 0, 12

If you assemble this and then run "objdump --debugging" on the resulting
object file (or linked executable), do you get the kind of output you
would expect, describing function "example" ?  If not, then this would
indicate that the stabs directives that you are using are wrong/incomplete.

> If I assemble that (as -gstabs), then add-symbol-file a.out, gdb knows
> about it but won't resolve it in backtraces.

You may find that asking this question on the gdb mailing list also helps.
Ie, it is possible that this is a gdb specific problem...

> What am I doing wrong?

My guess - you need to provide more stabs information.  Are you able to
compile a real C source file and capture the assembler output so that
you can compare the compiler generated stabs directives to your own ?

> Also, is there a better way to accomplish what I'm trying to do?

I don't think so.  There may be a gdb command that associates an address
with a symbol name, but I do not know what it is.  Sorry.

Cheers
   Nick