Re: [PATCH] objtool: Fix GCC 8 cold function processing without -freorder-functions

From: Josh Poimboeuf
Date: Wed Jun 27 2018 - 11:15:50 EST


On Wed, Jun 27, 2018 at 10:35:03AM +0100, Allan Xavier wrote:
> Looks good overall, just one comment.
>
> On 26/06/18 19:44, Josh Poimboeuf wrote:
> > + /*
> > + * Unfortunately, -fnoreorder-functions puts the child
> > + * inside the parent. Remove the overlap so we can
> > + * have sane assumptions.
> > + */
> > + if (sym->sec == pfunc->sec &&
> > + sym->offset >= pfunc->offset &&
> > + sym->offset < pfunc->offset + pfunc->len &&
> > + sym->offset + sym->len == pfunc->offset + pfunc->len) {
> > + pfunc->len -= sym->len;
>
> It's a bit of a nit but I'd say you could drop the third condition of the if
> since sym->offset would have to be less than pfunc->offset + pfunc->len for the
> fourth condition to ever be true. The only situation it would have caught is
> where sym->len == 0, which I think (hope?) is reasonable to assume wont happen
> and wouldn't have had an effect on pfunc->len anyway.
>
> if (sym->sec == pfunc->sec &&
> sym->offset >= pfunc->offset &&
> sym->offset + sym->len == pfunc->offset + pfunc->len)

Thanks, will do.

--
Josh