Re: [PATCH 7/7] xen/device_tree: Fix MISRA C 2012 Rule 20.7 violations

[Xenia Ragiadakou <burzalodowa@xxxxxxxxx>]

On 8/26/22 09:21, Jan Beulich wrote:
> On 25.08.2022 20:09, Stefano Stabellini wrote:
> > But first, let's confirm whether this change:
> >
> >
> >   #define dt_for_each_property_node(dn, pp)                   \
> > -    for ( pp = dn->properties; pp != NULL; pp = pp->next )
> > +    for ( pp = (dn)->properties; pp != NULL; pp = (pp)->next )
> >
> >
> > is sufficient to make the violation go away in Eclair or cppcheck.  I am
> > assuming it is not sufficient, but let's confirm.
> Well, even if for the lhs of assignments there was an exception, this
> still wouldn't be sufficient. The minimum needed is
>
> #define dt_for_each_property_node(dn, pp)                   \
>      for ( pp = (dn)->properties; (pp) != NULL; pp = (pp)->next )
If pp is assumed to be a valid lvalue, then why it is needed to add 
parentheses here (pp) != NULL ?
For the violations to go away, parentheses should be placed around all 
macro parameters that represent expressions, that is
#define dt_for_each_property_node(dn, pp)                   \
      for ( (pp) = (dn)->properties; (pp) != NULL; (pp) = (pp)->next )

--
Xenia