Re: [XEN PATCH 3/7] xen/arm: address MISRA C:2012 Rule 2.1

[Michal Orzel]

On 11/12/2023 13:29, Julien Grall wrote:
> 
> 
> Hi,
> 
> On 11/12/2023 10:30, Nicola Vetrini wrote:
>> The "return 1;" statements at the end of some cases in the switch
>> of function 'vgic_v3_its_mmio_write' in 'vcig-v3-its.c' cause the
>> unreachability of the "return 1;" statement after the switch, thus
>> violating MISRA C:2012 Rule 2.1:
>> "A project shall not contain unreachable code".
>>
>> The same is true for the switch in 'arch_memory_op' from
>> 'xen/arch/arm/mm.c'.
> 
> For both cases, I actually much prefer the "return" version in the
> cases. In particular for the vGIC emulation the switch is quite large
> and it would not be trivial to know what happens after the break.
Because of this...

> 
> IOW, I would much prefer if we remove the "return ..." outside of the
> switch.
wouldn't it be better to add ASSERT_UNREACHABLE() before this return instead of 
removing it?
This is what we have in e.g. vpl011 and it prevents mistakes.

~Michal