[PATCH 1/1] gdb, infrun: refactor part of `proceed` into separate function

[Andrew Burgess]

Christina Schimpe via Gdb-patches <gdb-patches@sourceware.org> writes:

> From: Mihails Strasuns <mihails.strasuns@intel.com>
>
> Split thread resuming block into separate function.
> ---
>  gdb/infrun.c | 119 ++++++++++++++++++++++++++-------------------------
>  1 file changed, 60 insertions(+), 59 deletions(-)
>
> diff --git a/gdb/infrun.c b/gdb/infrun.c
> index 58da1cef29e..571cf29ef32 100644
> --- a/gdb/infrun.c
> +++ b/gdb/infrun.c
> @@ -3268,6 +3268,63 @@ check_multi_target_resumption (process_stratum_target *resume_target)
>      }
>  }
>  
> +/* Helper function for `proceed`, does bunch of checks to see
> +   if a thread can be resumed right now, switches to that thread
> +   and moves on to `keep_going_pass_signal`.  */

Function comments are suppose to mention the function arguments.  So I'd
prefer something like:

  /* Helper function for `proceed`.  Check if thread TP is suitable for
     resuming, and, if it is, switch to the thread and call
     `keep_going_pass_signal`.  If TP is not suitable for resuming then
     this function will just return without switching threads.  */

> +
> +static void
> +proceed_resume_thread_checked (thread_info *tp)
> +{
> +  if (!tp->inf->has_execution ())
> +    {
> +      infrun_debug_printf ("[%s] target has no execution",
> +			   tp->ptid.to_string ().c_str ());
> +      return;
> +    }
> +
> +  if (tp->resumed ())
> +    {
> +      infrun_debug_printf ("[%s] resumed",
> +			   tp->ptid.to_string ().c_str ());
> +      gdb_assert (tp->executing () || tp->has_pending_waitstatus ());
> +      return;
> +    }
> +
> +  if (thread_is_in_step_over_chain (tp))
> +    {
> +      infrun_debug_printf ("[%s] needs step-over",
> +			   tp->ptid.to_string ().c_str ());
> +      return;
> +    }
> +
> +  /* If a thread of that inferior is waiting for a vfork-done
> +     (for a detached vfork child to exec or exit), breakpoints are
> +     removed.  We must not resume any thread of that inferior, other
> +     than the one waiting for the vfork-done.
> +     In non-stop, forbid resuming a thread if some other thread of
> +     that inferior is waiting for a vfork-done event (this means
> +     breakpoints are out for this inferior).  */

It feels like there's duplication between the two parts of this comment
now.  I think you need to rewrite this as a single comment block that
explains the new merged logic here.

Thanks,
Andrew

> +
> +  if (tp->inf->thread_waiting_for_vfork_done != nullptr
> +      && (tp != tp->inf->thread_waiting_for_vfork_done
> +	  || non_stop))
> +    {
> +      infrun_debug_printf ("[%s] another thread of this inferior is "
> +			   "waiting for vfork-done",
> +			   tp->ptid.to_string ().c_str ());
> +      return;
> +    }
> +
> +  infrun_debug_printf ("resuming %s",
> +		       tp->ptid.to_string ().c_str ());
> +
> +  execution_control_state ecs (tp);
> +  switch_to_thread (tp);
> +  keep_going_pass_signal (&ecs);
> +  if (!ecs.wait_some_more)
> +    error (_("Command aborted."));
> +}
> +
>  /* Basic routine for continuing the program in various fashions.
>  
>     ADDR is the address to resume at, or -1 for resume where stopped.
> @@ -3456,67 +3513,11 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal)
>  						       resume_ptid))
>  	  {
>  	    switch_to_thread_no_regs (tp);
> -
> -	    if (!tp->inf->has_execution ())
> -	      {
> -		infrun_debug_printf ("[%s] target has no execution",
> -				     tp->ptid.to_string ().c_str ());
> -		continue;
> -	      }
> -
> -	    if (tp->resumed ())
> -	      {
> -		infrun_debug_printf ("[%s] resumed",
> -				     tp->ptid.to_string ().c_str ());
> -		gdb_assert (tp->executing () || tp->has_pending_waitstatus ());
> -		continue;
> -	      }
> -
> -	    if (thread_is_in_step_over_chain (tp))
> -	      {
> -		infrun_debug_printf ("[%s] needs step-over",
> -				     tp->ptid.to_string ().c_str ());
> -		continue;
> -	      }
> -
> -	    /* If a thread of that inferior is waiting for a vfork-done
> -	       (for a detached vfork child to exec or exit), breakpoints are
> -	       removed.  We must not resume any thread of that inferior, other
> -	       than the one waiting for the vfork-done.  */
> -	    if (tp->inf->thread_waiting_for_vfork_done != nullptr
> -		&& tp != tp->inf->thread_waiting_for_vfork_done)
> -	      {
> -		infrun_debug_printf ("[%s] another thread of this inferior is "
> -				     "waiting for vfork-done",
> -				     tp->ptid.to_string ().c_str ());
> -		continue;
> -	      }
> -
> -	    infrun_debug_printf ("resuming %s",
> -				 tp->ptid.to_string ().c_str ());
> -
> -	    execution_control_state ecs (tp);
> -	    switch_to_thread (tp);
> -	    keep_going_pass_signal (&ecs);
> -	    if (!ecs.wait_some_more)
> -	      error (_("Command aborted."));
> +	    proceed_resume_thread_checked (tp);
>  	  }
>        }
> -    else if (!cur_thr->resumed ()
> -	     && !thread_is_in_step_over_chain (cur_thr)
> -	     /* In non-stop, forbid resuming a thread if some other thread of
> -		that inferior is waiting for a vfork-done event (this means
> -		breakpoints are out for this inferior).  */
> -	     && !(non_stop
> -		  && cur_thr->inf->thread_waiting_for_vfork_done != nullptr))
> -      {
> -	/* The thread wasn't started, and isn't queued, run it now.  */
> -	execution_control_state ecs (cur_thr);
> -	switch_to_thread (cur_thr);
> -	keep_going_pass_signal (&ecs);
> -	if (!ecs.wait_some_more)
> -	  error (_("Command aborted."));
> -      }
> +    else
> +      proceed_resume_thread_checked (cur_thr);
>  
>      disable_commit_resumed.reset_and_commit ();
>    }
> -- 
> 2.25.1
>
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