Re: [reverse RFA] no singlestep-over-BP in reverse

[teawater <teawater@gmail.com>]

I think maybe some reverse target (in the future?) need it.
Someone already know it already deal the breakpoint. But the others
will not know. Maybe I will change inside record to second type.


If this single step affect some target, how about let target choice it
with itself?

Thanks,
Hui




On Tue, Sep 16, 2008 at 02:31, Michael Snyder <msnyder@vmware.com> wrote:
> When we're stopped at a breakpoint and we want to
> continue in reverse, we're not actually going to
> execute the instruction at the breakpoint -- we're
> going to de-execute the previous instruction.
>
> Therefore there's no need to singlestep before
> inserting breakpoints.  In fact it would be a bad
> idea to do so, because if there is a breakpoint at
> the previous instruction, we WANT to hit it.
>
> Note that this patch is to be applied to the reverse branch.
>
> 2008-09-15  Michael Snyder  <msnyder@vmware.com>
>
>        * infrun.c (proceed): No need to singlestep over a breakpoint
>        when resuming in reverse.
>
> Index: infrun.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/infrun.c,v
> retrieving revision 1.300.2.5
> diff -u -p -r1.300.2.5 infrun.c
> --- infrun.c    5 Sep 2008 03:37:10 -0000       1.300.2.5
> +++ infrun.c    15 Sep 2008 18:28:29 -0000
> @@ -1226,11 +1226,17 @@ proceed (CORE_ADDR addr, enum target_sig
>
>   if (addr == (CORE_ADDR) -1)
>     {
> -      if (pc == stop_pc && breakpoint_here_p (pc))
> +      if (pc == stop_pc && breakpoint_here_p (pc)
> +         && target_get_execution_direction () == EXEC_FORWARD)
>        /* There is a breakpoint at the address we will resume at,
>           step one instruction before inserting breakpoints so that
>           we do not stop right away (and report a second hit at this
> -          breakpoint).  */
> +          breakpoint).
> +
> +          Note, we don't do this in reverse, because we won't
> +          actually be executing the breakpoint insn anyway.
> +          We'll be (un-)executing the previous instruction.  */
> +
>        oneproc = 1;
>       else if (gdbarch_single_step_through_delay_p (gdbarch)
>               && gdbarch_single_step_through_delay (gdbarch,
>
>