Re: [PATCH v2] gdb/arm: Stop unwinding on error, but do not assert

[Pedro Alves <pedro@palves.net>]

On 2022-10-13 10:17 a.m., Torbjörn SVENSSON via Gdb-patches wrote:

> +  /* Unwind of this frame is not possible.  Return outer_frame_id to stop the
> +     unwinding.  */
> +  if (cache == NULL)
> +    {
> +      *this_id = outer_frame_id;
> +      return;
> +    }

Please let's not add more uses of outer_frame_id if we can avoid it.  We're getting
close to eliminating it.  Can a cache object still be returned, and then a frame id
be successfully computed?  

You can stop the unwinding in some other way.  For example, arm_m_exception_cache has a few
of these:

	      /* Terminate any further stack unwinding by referring to self.  */
	      arm_cache_set_active_sp_value (cache, tdep, sp);
	      return cache;

(Not sure exactly how that works.)

Alternatively, you can implement a frame_unwind::stop_reason callback and return
UNWIND_OUTERMOST, which is already done in arm-tdep.c in other scenarios too.