Re: [RFA] Patch to fix "reverse-next" command error

[Hui Zhu <teawater@gmail.com>]

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Hi Michael,

I try this issue with cvs-head.  It still affect cvs-head.
And I try the patch, it can fix this issue.  It's time close to 7.0
branch.  So could you please help me review it?

The attachment is the new patch follow cvs-head.

2009-05-06  Hui Zhu  <teawater@gmail.com>

       * infrun.c (handle_inferior_event): Make inferior step if it
       stepping over a function call in reverse , and stop at the
       start address of the function.

Thanks,
Hui

On Thu, Jan 22, 2009 at 17:00, teawater <teawater@gmail.com> wrote:
> Hi guys,
>
> This patch is for bug in http://sourceware.org/ml/gdb/2009-01/msg00146.html
>
> This issue is because sometime the inferior is already in function
> start address (i.e. plt), set a breakpoint and continue will make
> "reverse-next" work error.
>
> This patch make inferior step if it reverse step and stop at the
> function start address.
> It tested OK with process record patch and testsuite gdb.twreverse in
> branch reverse-20081226-branch.
>
> 2009-01-22  Hui Zhu  <teawater@gmail.com>
>
>        * infrun.c (handle_inferior_event): Make inferior step if it
>        stepping over a function call in reverse , and stop at the
>        start address of the function.
>
> OK for mainline?
>
> Thanks,
> Hui
>

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---
 infrun.c |   19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

--- a/infrun.c
+++ b/infrun.c
@@ -3558,10 +3558,21 @@ infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (
 		  keep_going (ecs);
 		  return;
 		}
-	      /* Normal (staticly linked) function call return.  */
-	      init_sal (&sr_sal);
-	      sr_sal.pc = ecs->stop_func_start;
-	      insert_step_resume_breakpoint_at_sal (sr_sal, null_frame_id);
+	      if (ecs->stop_func_start != stop_pc)
+		{
+		  /* Normal (staticly linked) function call return.  */
+		  init_sal (&sr_sal);
+		  sr_sal.pc = ecs->stop_func_start;
+		  insert_step_resume_breakpoint_at_sal (sr_sal, null_frame_id);
+		}
+	      else
+		{
+		  /* We are stepping over a function call in reverse, and
+	             stop at the start address of the function.  Go back to
+	             single-stepping, which should take us back to the
+	             function call.  */
+		  ecs->event_thread->stepping_over_breakpoint = 1;
+		}
 	    }
 	  else
 	    insert_step_resume_breakpoint_at_caller (get_current_frame ());