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

[Hui Zhu <teawater at gmail dot com>]

On Mon, Jun 15, 2009 at 10:45, Michael Snyder<msnyder@vmware.com> wrote:
> Hui Zhu wrote:
>>
>> Ping.
>
> Hui, I rewrote your patch a little bit. ?I think we can use
> gdbarch_skip_trampoline_code to detect the fact that we have
> stepped into a trampoline (ie. "plt"). ?This is more general.
>
> Mark, please tell me if this patch fixes your original problem,
> and Hui, please tell me if the patch is OK with you.
>

This patch is OK with me.

BTW, the patch that you sent include the prev one.


Thanks,
Hui

>> On Mon, May 11, 2009 at 15:07, Hui Zhu<teawater@gmail.com> wrote:
>>>
>>> PING
>>>
>>> On Wed, May 6, 2009 at 14:00, Hui Zhu <teawater@gmail.com> wrote:
>>>>
>>>> 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
>>>>>
>>
>
>
> 2009-06-14 ?Hui Zhu ?<teawater@gmail.com>
> ? ? ? ? ? ?Michael Snyder ?<msnyder@vmware.com>
>
> ? ? ? ?* infrun.c (handle_inferior_event): Reverse-next through trampoline.
>
> Index: infrun.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/infrun.c,v
> retrieving revision 1.387
> diff -u -p -r1.387 infrun.c
> --- infrun.c ? ?11 Jun 2009 11:57:46 -0000 ? ? ?1.387
> +++ infrun.c ? ?15 Jun 2009 02:39:51 -0000
> @@ -3623,9 +3623,17 @@ infrun: not switching back to stepped th
>
> ? ? ?Note that step_range_end is the address of the first instruction
> ? ? ?beyond the step range, and NOT the address of the last instruction
> - ? ? within it! */
> + ? ? within it!
> +
> + ? ? Note also that during reverse execution, we may be stepping
> + ? ? through a function epilogue and therefore must detect when
> + ? ? the current-frame changes in the middle of a line. ?*/
> +
> ? if (stop_pc >= ecs->event_thread->step_range_start
> - ? ? ?&& stop_pc < ecs->event_thread->step_range_end)
> + ? ? ?&& stop_pc < ecs->event_thread->step_range_end
> + ? ? ?&& (execution_direction != EXEC_REVERSE
> + ? ? ? ? || frame_id_eq (get_frame_id (get_current_frame ()),
> + ? ? ? ? ? ? ? ? ? ? ? ? ecs->event_thread->step_frame_id)))
> ? ? {
> ? ? ? if (debug_infrun)
> ? ? ? ?fprintf_unfiltered (gdb_stdlog, "infrun: stepping inside range
> [0x%s-0x%s]\n",
> @@ -3762,10 +3770,21 @@ infrun: not switching back to stepped th
> ? ? ? ? ? ? ? ? ?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 (gdbarch_skip_trampoline_code(current_gdbarch,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?get_current_frame (),
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?stop_pc))
> + ? ? ? ? ? ? ? {
> + ? ? ? ? ? ? ? ? /* We are in a function call trampoline.
> + ? ? ? ? ? ? ? ? ? ?Keep stepping backward to get to the caller. ?*/
> + ? ? ? ? ? ? ? ? ecs->event_thread->stepping_over_breakpoint = 1;
> + ? ? ? ? ? ? ? }
> + ? ? ? ? ? ? else
> + ? ? ? ? ? ? ? {
> + ? ? ? ? ? ? ? ? /* Normal function call return (static or dynamic). ?*/
> + ? ? ? ? ? ? ? ? init_sal (&sr_sal);
> + ? ? ? ? ? ? ? ? sr_sal.pc = ecs->stop_func_start;
> + ? ? ? ? ? ? ? ? insert_step_resume_breakpoint_at_sal (sr_sal,
> null_frame_id);
> + ? ? ? ? ? ? ? }
> ? ? ? ? ? ?}
> ? ? ? ? ?else
> ? ? ? ? ? ?insert_step_resume_breakpoint_at_caller (get_current_frame ());
>
>