Re: [XEN PATCH v2] misra: address violation of MISRA C Rule 10.1

[Dmytro Prokopchuk1 <dmytro_prokopchuk1@xxxxxxxx>]

On 7/11/25 15:03, Jan Beulich wrote:
> On 11.07.2025 13:43, Dmytro Prokopchuk1 wrote:
>> --- a/xen/common/memory.c
>> +++ b/xen/common/memory.c
>> @@ -773,7 +773,7 @@ static long 
>> memory_exchange(XEN_GUEST_HANDLE_PARAM(xen_memory_exchange_t) arg)
>>   
>>                   nrspin_lock(&d->page_alloc_lock);
>>                   drop_dom_ref = (dec_count &&
>> -                                !domain_adjust_tot_pages(d, -dec_count));
>> +                                !domain_adjust_tot_pages(d, 
>> -(long)dec_count));
> 
> Here and elsewhere I continue to think that we would better avoid casts
> in such cases as well, just like we try to minimize their use everywhere
> else.
Got it!

> 
>> --- a/xen/common/time.c
>> +++ b/xen/common/time.c
>> @@ -84,7 +84,7 @@ struct tm gmtime(unsigned long t)
>>       }
>>       tbuf.tm_year = y - 1900;
>>       tbuf.tm_yday = days;
>> -    ip = (const unsigned short int *)__mon_lengths[__isleap(y)];
>> +    ip = (const unsigned short int *)__mon_lengths[__isleap(y) ? 1 : 0];
> 
> If an expression is needed here, I'd suggest to use !!, as we have in
> (luckily decreasing) number of places elsewhere. Personally I don't
> understand though why a boolean cannot be used as an array index.
> 
>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>> @@ -315,7 +315,7 @@ static int queue_poll_cons(struct arm_smmu_queue *q, 
>> bool sync, bool wfe)
>>   
>>      while (queue_sync_cons_in(q),
>>            (sync ? !queue_empty(&q->llq) : queue_full(&q->llq))) {
>> -            if ((NOW() > timeout) > 0)
>> +            if (NOW() > timeout)
>>                      return -ETIMEDOUT;
> 
> How does this change fit here?
> 
> Jan

if ((NOW() > timeout) > 0)
Result of "(NOW() > timeout)" is Boolean, so we have comparison Boolean 
with Numeric value.