Hi!
On Fri, Nov 04, 2016 at 10:17:31AM +0100, Martin Liška wrote:
> diff --git a/gcc/gimplify.c b/gcc/gimplify.c
> index 813777d..86ce793 100644
> --- a/gcc/gimplify.c
> +++ b/gcc/gimplify.c
> @@ -1678,7 +1678,9 @@ warn_switch_unreachable_r (gimple_stmt_iterator *gsi_p,
> bool *handled_ops_p,
> worse location info. */
> if (gimple_try_eval (stmt) == NULL)
> {
> - wi->info = stmt;
> + gimple_stmt_iterator *it = XNEW (gimple_stmt_iterator);
> + memcpy (it, gsi_p, sizeof (gimple_stmt_iterator));
That would be cleaner as *it = *gsi_p;
That set, I fail to see
1) the need to use a gsi pointer in wi->info compared to stmt itself,
you can gsi_for_stmt cheaply at any time
2) why is anything done about this in warn_switch_unreachable_r
- the problem isn't related to this warning IMHO. Even
switch (x)
{
case 1:
int x;
x = 6;
ptr = &x;
break;
case 2:
ptr = &x;
*ptr = 7;
break;
}
has the same issue and there is no switch unreachable code there, but you
still want for -fsanitize-use-after-scope pretend it is actually:
x_tmp = x;
{
int x;
switch (x_tmp)
{
case 1:
x = 6;
ptr = &x;
break;
case 2:
ptr = &x;
*ptr = 7;
break;
}
}
and put ASAN_MARK unpoisoning before GIMPLE_SWITCH.
Jakub
