Re: [PATCH 1/2] xen/arm: asm/atomic.h: Fix MISRA C 2012 Rule 20.7 violation

[Xenia Ragiadakou <burzalodowa@xxxxxxxxx>]

Hi Jan,

On 7/27/22 18:36, Jan Beulich wrote:
> On 27.07.2022 17:32, Xenia Ragiadakou wrote:
> > The macro parameter 'p' is used as an expression and needs to be enclosed in
> > parentheses.
> Yes, but ...
>
> > --- a/xen/arch/arm/include/asm/atomic.h
> > +++ b/xen/arch/arm/include/asm/atomic.h
> > @@ -123,15 +123,15 @@ static always_inline void write_atomic_size(volatile void 
> > *p,
> >   }
> >   
> >   #define read_atomic(p) ({                                               \
> > -    union { typeof(*p) val; char c[0]; } x_;                            \
> > -    read_atomic_size(p, x_.c, sizeof(*p));                              \
> > +    union { typeof(*(p)) val; char c[0]; } x_;                          \
> > +    read_atomic_size((p), x_.c, sizeof(*(p)));                          \
> ... not in the first argument's case - that's not an expression.
> Too few parentheses are a risk, but too many are as well, as they
> negatively affect readability.
Yes you are right. Here
write_atomic_size((p), &x_, sizeof(*(p)));
as well.

I will fix and resend.

--
Xenia