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Re: [reverse/record] adjust_pc_after_break in reverse execution mode?
In replay mode, it can't change value of register.
So I just can check if some address have breakpoint and stop execute
in this address.
On Tue, Oct 21, 2008 at 08:21, Pedro Alves <pedro@codesourcery.com> wrote:
> On Tuesday 21 October 2008 00:36:12, teawater wrote:
>> I think your mean is check breakpoint in address
>> read_pc()+gdbarch_decr_pc_after_break (gdbarch) in record_wait, right?
>
> Taking x86 as an example, when you're doing normal debugging and you
> hit a breakpoint (SIGTRAP), the first read_pc GDB does to check where
> what breakpoint was hit, will read back `breakpoint_PC + 1' --- GDB takes care
> getting rid of that `+ 1' offset in infrun.c:adjust_pc_after_break. The
> idea is for you to do the same as the kernel/hardware would --- still
> check for breakpoints at read_pc, but increment PC by 1 before reporting the
> breakpoint to GDB's core. E.g., see the `pc += gdbarch...' line from
> the patch I posted previously, something like:
>
> record.c:record_wait ()
> {
> ...
> + /* Check for breakpoint hits in forward execution. */
> + pc = read_pc ();
> + if (execution_direction == EXEC_FORWARD
> + && regular_breakpoint_inserted_here_p (pc)
> + /* && !single-stepping */)
> + {
> + status->kind = TARGET_WAITKIND_STOPPED;
> + status->value.sig = TARGET_SIGNAL_TRAP;
> + if (software_breakpoint_inserted_here_p (pc))
> + {
> + pc += gdbarch_decr_pc_after_break (gdbarch);
> + write_pc (pc);
> + }
> +
>
> --
> Pedro Alves
>