Re: [PATCH] xen: address violation of MISRA C Rule 11.1

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 11 Dec 2024, Jan Beulich wrote:
> On 11.12.2024 12:02, Alessandro Zucchelli wrote:
> > Rule 11.1 states as following: "Conversions shall not be performed
> > between a pointer to a function and any other type".
> > 
> > Functions "__machine_restart" and "__machine_halt" in "x86/shutdown.c"
> > and "halt_this_cpu" in "arm/shutdown.c" are defined as noreturn
> > functions and subsequently passed as parameters to function calls.
> > This violates the rule in Clang, where the "noreturn" attribute is
> > considered part of the function"s type.
> 
> I'm unaware of build issues with Clang, hence can you clarify how Clang's
> view comes into play here? In principle various attributes ought to be
> part of a function's type; iirc that's also the case for gcc. Yet how
> that matters to Eclair is still entirely unclear to me.
> 
> > By removing the "noreturn"
> > attribbute and replacing it with uses of the ASSERT_UNREACHABLE macro,
> > these violations are addressed.
> 
> Papered over, I'd say. What about release builds, for example?
> 
> Deleting the attribute also has a clear downside documentation-wise. If
> we really mean to remove them from what the compiler gets to see, I think
> we ought to still retain them in commented-out shape.

Another option would be to #define noreturn to nothing for ECLAIR builds ?