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

[Hui Zhu <teawater@gmail.com>]

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Hi Marc and Michael,

Sorry I forget this issue just reproduce in SLED 10.

I reproduced it with cvs-head and patch can fix it.  Michael, 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 insert
       breakpoint at right address or step in reverse and it stepped
       into dynsym resolve code.

Thanks,
Hui

On Wed, May 6, 2009 at 13:31, Hui Zhu <teawater@gmail.com> wrote:
> Hi Marc,
>
> I cannot reproduce this issue with cvs-head.
> Could you please help me test with this issue?
> If both of us cannot reproduce this issue,  I think I can give up this patch.
>
> Thanks,
> Hui
>
>
> On Mon, Mar 2, 2009 at 14:10, teawater <teawater@gmail.com> wrote:
>> Hi Michael,
>>
>> This patch is for bug in
>> http://sourceware.org/ml/gdb-patches/2009-02/msg00246.html.
>>
>> The reason of bug is when inferior reverse exection into dynsym
>> resolve code, gdb doesn't insert breakpoint in right address.
>> It just happen in some distributions for example SLED.
>>
>> This patch make gdb insert breakpoint in right address or step in that case.
>>
>> 2008-03-02  Hui Zhu  <teawater@gmail.com>
>>
>>       * infrun.c (handle_inferior_event): Make inferior insert
>>       breakpoint at right address or step in reverse and it stepped
>>       into dynsym resolve code.
>>
>> Thanks,
>> Hui
>>
>

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---
 infrun.c |   31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)

--- a/infrun.c
+++ b/infrun.c
@@ -3465,13 +3465,34 @@ infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (
 
       if (pc_after_resolver)
 	{
-	  /* Set up a step-resume breakpoint at the address
-	     indicated by SKIP_SOLIB_RESOLVER.  */
 	  struct symtab_and_line sr_sal;
-	  init_sal (&sr_sal);
-	  sr_sal.pc = pc_after_resolver;
+	  if (execution_direction == EXEC_REVERSE)
+	    {
+	      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
+	    {
+	      /* Set up a step-resume breakpoint at the address
+	         indicated by SKIP_SOLIB_RESOLVER.  */
+	      init_sal (&sr_sal);
+	      sr_sal.pc = pc_after_resolver;
 
-	  insert_step_resume_breakpoint_at_sal (sr_sal, null_frame_id);
+	      insert_step_resume_breakpoint_at_sal (sr_sal, null_frame_id);
+	    }
 	}
 
       keep_going (ecs);