Re: [RFC PATCH 0/5] of: automate of_node_put() - new approach to loops.

From: Jonathan Cameron
Date: Thu Feb 01 2024 - 10:24:00 EST


> > 3) Introduced the pointer to auto put device_node only within the
> > for loop scope.
> >
> > +#define for_each_child_of_node_scoped(parent, child) \
> > + for (struct device_node *child __free(device_node) = \
> > + of_get_next_child(parent, NULL); \
> > + child != NULL; \
>
> Just
>
> child;

Agreed that's the same, but was thinking to follow local style.
I don't feel strongly though so fine with dropping the != NULL

>
> > + child = of_get_next_available_child(parent, child))
> > +
> >
> > This series is presenting option 3. I only implemented this loop out of
> > all the similar ones and it is only compile tested.
> >
> > Disadvantage Rob raised is that it isn't obvious this macro will instantiate
> > a struct device_node *child. I can't see a way around that other than option 2
> > above, but all suggestions welcome. Note that if a conversion leaves an
> > 'external' struct device_node *child variable, in many cases the compiler
> > will catch that as an unused variable. We don't currently run shaddow
> > variable detection in normal kernel builds, but that could also be used
> > to catch such bugs.
>