Re: [PATCH 1/4] xen/arm: traps: Fix MISRA C 2012 Rule 8.4 violations

[Julien Grall <julien@xxxxxxx>]

Hi Xenia,

On 05/07/2022 22:49, Xenia Ragiadakou wrote:
> On 7/6/22 00:28, Julien Grall wrote:
> > Hi Xenia,
> >
> > On 05/07/2022 22:02, Xenia Ragiadakou wrote:
> > > Add the function prototypes of the functions below in 
> > > <asm/processor.h> header
> > > file so that they are visible before the function definitions in 
> > > traps.c.
> > > enter_hypervisor_from_guest_preirq()
> > > enter_hypervisor_from_guest()
> > > do_trap_hyp_sync()
> > > do_trap_guest_sync()
> > > do_trap_irq()
> > > do_trap_fiq()
> > > leave_hypervisor_to_guest()
> > I have actually came across those missing prototypes in the past and I 
> > have refrained to add them because they are not meant to be called 
> > from C.
> > While I agree this is a violation of Misra C, I am still not convinced 
> > they should be added (there is no need to verify the prototype).
> Yes, there is no need. Here, I decided to follow the example of 
> do_trap_hyp_serror() and do_trap_guest_serror() for consistency.
do_trap_guest_serror() is called from C code (see arch/arm32/traps.c).

do_trap_hyp_serror() is called only from assembly. I would argue that if 
you want consistency, then you should drop the prototype rather than 
modifying 90% of the other examples.
Otherwise, this is not really consistency but more a design choice (you 
want to be fully compliant with MISRA).
Cheers,

--
Julien Grall