Re: [XEN PATCH 10/11] xen/sched: add ASSERT_UNREACHABLE() to address MISRA C:2012 Rule 2.1

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

On 03/08/2023 11:17, Jan Beulich wrote:
> On 02.08.2023 16:38, Nicola Vetrini wrote:
> > --- a/xen/common/sched/core.c
> > +++ b/xen/common/sched/core.c
> > @@ -2233,6 +2233,7 @@ static bool sched_tasklet_check_cpu(unsigned int 
> > cpu)
> >          /* fallthrough */
> >      case TASKLET_enqueued|TASKLET_scheduled:
> >          return true;
> > +        ASSERT_UNREACHABLE();
> >          break;
> What use is "break" after "return"? IOW rather than adding code here,
> imo a line wants removing.
>
> Jan
The "return false" after the switch would still be unreachable. The 
reasoning behind preserving the break
is mainly MISRA Rule 16.3: "An unconditional break statement shall 
terminate every switch-clause", which has
not yet been considered for adoption, but might be in future 
discussions, leading to putting back the break here.
--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)