Re: [RFA] use frame IDs to detect function calls while stepping

[Andrew Cagney <cagney@gnu.org>]

> On Thu, Feb 05, 2004 at 02:20:10PM -0500, Elena Zannoni wrote:
> 
>> Daniel Jacobowitz writes:
>> 
>>  > > +      if (IN_SOLIB_CALL_TRAMPOLINE (stop_pc, ecs->stop_func_name))
>>  > > +        {
>>  > > +          /* We landed in a shared library call trampoline, so it
>>  > > +             is a subroutine call.  */
>>  > > +          handle_step_into_function (ecs);
>>  > > +          return;
>>  > > +        }
>>  > > +
>>  > > +      if (frame_id_eq (get_frame_id (get_prev_frame (get_current_frame ())),
>>  > > +                       step_frame_id))
>>  > > +        {
>>  > > +          /* It's a subroutine call.  */
>>  > > +          handle_step_into_function (ecs);
>>  > > +          return;
>>  > > +        }
>>  > > +
>>  > 
>>  > get_prev_frame can return NULL.  In fact, it generally does in main.
>>  > 
>> 
>> I don't think it matters, frame_id_eq will handle a comparison with
>> null_frame_id.
> 
> 
> Oh, you're right - I was expecting get_frame_id (NULL) to be a problem,
> but it isn't.

Hmm, I suspect there's a latent bug here.  In this context, when at 
main, get_prev_frame should unconditionally return main's caller.  Even 
when backtrace-beyond-main is false.

This suggests that some of the conditions found in get_prev_frame 
(namely in_entry_func and in_main_func) should be separated out.

However, that can be sorted later.

Andrew