Re: [RFC] Add step_stack_prev_frame_id

[Hui Zhu <teawater@gmail.com>]

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Add the attachment.

On Tue, Jul 7, 2009 at 17:29, Hui Zhu<teawater@gmail.com> wrote:
> Hi,
>
> Now, reverse debug have a problem about infrun doesn't know the
> frame_id of prev function.  So it will not know inferior stepped into
> subroutine or stepped out from subroutine.
> http://sourceware.org/ml/gdb/2009-06/msg00089.html
> This mail talk about this issue.
>
> Daniel suggest us to use "frame_unwind_caller_id" and Michael make
> some patch for it.  Looks it's depend on arch code support and new
> version gcc support.
>
> I have other idea about it.
> http://sourceware.org/ml/gdb-patches/2009-06/msg00793.html
> Save this prev_frame_id when we save step_stack_prev_frame_id in
> reverse mode.  I made a patch for it.
> I think it will not depend on arch code support and new version gcc
> support.  I try it with precord AMD64 patch.
>
>
> Thanks,
> Hui
>
>
> 2009-07-07  Hui Zhu  <teawater@gmail.com>
>
>        * gdbthread.h (thread_info): Add step_stack_prev_frame_id to
>        save the prev_frame_id when we can get the prev_frame.
>        * infrun.c (inferior_status): Ditto.
>        (save_inferior_status): Ditto.
>        (restore_inferior_status): Ditto.
>        (set_step_info): Get the step_stack_prev_frame_id.
>        (handle_inferior_event): Use the step_stack_prev_frame_id make
>        sure inferior stepped into subroutine or not.
>
>
> ---
>  gdbthread.h |    3 +++
>  infrun.c    |   14 +++++++++++++-
>  2 files changed, 16 insertions(+), 1 deletion(-)
>
> --- a/gdbthread.h
> +++ b/gdbthread.h
> @@ -88,6 +88,9 @@ struct thread_info
>      any inlined frames).  */
>   struct frame_id step_stack_frame_id;
>
> +  /* The prev frame id of step_stack_frame_id.  */
> +  struct frame_id step_stack_prev_frame_id;
> +
>   int current_line;
>   struct symtab *current_symtab;
>
> --- a/infrun.c
> +++ b/infrun.c
> @@ -2153,10 +2153,17 @@ void
>  set_step_info (struct frame_info *frame, struct symtab_and_line sal)
>  {
>   struct thread_info *tp = inferior_thread ();
> +  struct frame_info *prev_frame;
>
>   tp->step_frame_id = get_frame_id (frame);
>   tp->step_stack_frame_id = get_stack_frame_id (frame);
>
> +  prev_frame = get_prev_frame (frame);
> +  if (prev_frame)
> +    tp->step_stack_prev_frame_id = get_stack_frame_id (prev_frame);
> +  else
> +    tp->step_stack_prev_frame_id = null_frame_id;
> +
>   tp->current_symtab = sal.symtab;
>   tp->current_line = sal.line;
>  }
> @@ -3778,7 +3785,9 @@ infrun: not switching back to stepped th
>                    ecs->event_thread->step_stack_frame_id)
>       && (frame_id_eq (frame_unwind_caller_id (frame),
>                       ecs->event_thread->step_stack_frame_id)
> -         || execution_direction == EXEC_REVERSE))
> +         || (execution_direction == EXEC_REVERSE
> +              && !frame_id_eq (get_stack_frame_id (frame),
> +                               ecs->event_thread->step_stack_prev_frame_id))))
>     {
>       CORE_ADDR real_stop_pc;
>
> @@ -5388,6 +5397,7 @@ struct inferior_status
>   CORE_ADDR step_range_end;
>   struct frame_id step_frame_id;
>   struct frame_id step_stack_frame_id;
> +  struct frame_id step_stack_prev_frame_id;
>   enum step_over_calls_kind step_over_calls;
>   CORE_ADDR step_resume_break_address;
>   int stop_after_trap;
> @@ -5418,6 +5428,7 @@ save_inferior_status (void)
>   inf_status->step_range_end = tp->step_range_end;
>   inf_status->step_frame_id = tp->step_frame_id;
>   inf_status->step_stack_frame_id = tp->step_stack_frame_id;
> +  inf_status->step_stack_prev_frame_id = tp->step_stack_prev_frame_id;
>   inf_status->step_over_calls = tp->step_over_calls;
>   inf_status->stop_after_trap = stop_after_trap;
>   inf_status->stop_soon = inf->stop_soon;
> @@ -5472,6 +5483,7 @@ restore_inferior_status (struct inferior
>   tp->step_range_end = inf_status->step_range_end;
>   tp->step_frame_id = inf_status->step_frame_id;
>   tp->step_stack_frame_id = inf_status->step_stack_frame_id;
> +  tp->step_stack_prev_frame_id = inf_status->step_stack_prev_frame_id;
>   tp->step_over_calls = inf_status->step_over_calls;
>   stop_after_trap = inf_status->stop_after_trap;
>   inf->stop_soon = inf_status->stop_soon;
>

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---
 gdbthread.h |    3 +++
 infrun.c    |   14 +++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

--- a/gdbthread.h
+++ b/gdbthread.h
@@ -88,6 +88,9 @@ struct thread_info
      any inlined frames).  */
   struct frame_id step_stack_frame_id;
 
+  /* The prev frame id of step_stack_frame_id.  */
+  struct frame_id step_stack_prev_frame_id;
+
   int current_line;
   struct symtab *current_symtab;
 
--- a/infrun.c
+++ b/infrun.c
@@ -2153,10 +2153,17 @@ void
 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
 {
   struct thread_info *tp = inferior_thread ();
+  struct frame_info *prev_frame;
 
   tp->step_frame_id = get_frame_id (frame);
   tp->step_stack_frame_id = get_stack_frame_id (frame);
 
+  prev_frame = get_prev_frame (frame);
+  if (prev_frame)
+    tp->step_stack_prev_frame_id = get_stack_frame_id (prev_frame);
+  else
+    tp->step_stack_prev_frame_id = null_frame_id;
+
   tp->current_symtab = sal.symtab;
   tp->current_line = sal.line;
 }
@@ -3778,7 +3785,9 @@ infrun: not switching back to stepped th
 		    ecs->event_thread->step_stack_frame_id)
       && (frame_id_eq (frame_unwind_caller_id (frame),
 		       ecs->event_thread->step_stack_frame_id)
-	  || execution_direction == EXEC_REVERSE))
+	  || (execution_direction == EXEC_REVERSE
+              && !frame_id_eq (get_stack_frame_id (frame),
+                               ecs->event_thread->step_stack_prev_frame_id))))
     {
       CORE_ADDR real_stop_pc;
 
@@ -5388,6 +5397,7 @@ struct inferior_status
   CORE_ADDR step_range_end;
   struct frame_id step_frame_id;
   struct frame_id step_stack_frame_id;
+  struct frame_id step_stack_prev_frame_id;
   enum step_over_calls_kind step_over_calls;
   CORE_ADDR step_resume_break_address;
   int stop_after_trap;
@@ -5418,6 +5428,7 @@ save_inferior_status (void)
   inf_status->step_range_end = tp->step_range_end;
   inf_status->step_frame_id = tp->step_frame_id;
   inf_status->step_stack_frame_id = tp->step_stack_frame_id;
+  inf_status->step_stack_prev_frame_id = tp->step_stack_prev_frame_id;
   inf_status->step_over_calls = tp->step_over_calls;
   inf_status->stop_after_trap = stop_after_trap;
   inf_status->stop_soon = inf->stop_soon;
@@ -5472,6 +5483,7 @@ restore_inferior_status (struct inferior
   tp->step_range_end = inf_status->step_range_end;
   tp->step_frame_id = inf_status->step_frame_id;
   tp->step_stack_frame_id = inf_status->step_stack_frame_id;
+  tp->step_stack_prev_frame_id = inf_status->step_stack_prev_frame_id;
   tp->step_over_calls = inf_status->step_over_calls;
   stop_after_trap = inf_status->stop_after_trap;
   inf->stop_soon = inf_status->stop_soon;