Re: [XEN PATCH 07/11] xen: address MISRA C:2012 Rule 2.1

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 3 Aug 2023, Jan Beulich wrote:
> On 02.08.2023 16:38, Nicola Vetrini wrote:
> > Rule 2.1 states: "A project shall not contain unreachable code".
> > 
> > The functions
> > - machine_halt
> > - maybe_reboot
> > - machine_restart
> > are not supposed to return, hence the following break statement
> > is marked as intentionally unreachable with the ASSERT_UNREACHABLE()
> > macro to justify the violation of the rule.
> 
> During the discussion it was mentioned that this won't help with
> release builds, where right now ASSERT_UNREACHABLE() expands to
> effectively nothing. You want to clarify here how release builds
> are to be taken care of, as those are what eventual certification
> will be run against.

Something along these lines:

ASSERT_UNREACHABLE(), not only is used in non-release builds to actually
assert and detect errors, but it is also used as a marker to tag
unreachable code. In release builds ASSERT_UNREACHABLE() doesn't resolve
into an assert, but retains its role of a code marker.

Does it work?