Re: [PATCH 4/6] xen/bitops: Introduce for_each_set_bit()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 26/06/2024 1:03 pm, Jan Beulich wrote:
> On 25.06.2024 21:07, Andrew Cooper wrote:
>> --- a/xen/include/xen/bitops.h
>> +++ b/xen/include/xen/bitops.h
>> @@ -56,6 +56,16 @@ static always_inline __pure unsigned int ffs64(uint64_t x)
>>          return !x || (uint32_t)x ? ffs(x) : ffs(x >> 32) + 32;
>>  }
>>  
>> +/*
>> + * A type-generic ffs() which picks the appropriate ffs{,l,64}() based on 
>> it's
>> + * argument.
>> + */
>> +#define ffs_g(x)                                        \
>> +    sizeof(x) <= sizeof(int) ? ffs(x) :                 \
>> +        sizeof(x) <= sizeof(long) ? ffsl(x) :           \
>> +        sizeof(x) <= sizeof(uint64_t) ? ffs64(x) :      \
>> +        ({ BUILD_ERROR("ffs_g() Bad input type"); 0; })
> I guess the lack of parentheses around the entire construct might be the
> reason for the problems you're seeing, as that ...
>
>> @@ -92,6 +102,20 @@ static always_inline __pure unsigned int fls64(uint64_t 
>> x)
>>      }
>>  }
>>  
>> +/*
>> + * for_each_set_bit() - Iterate over all set bits in a scalar value.
>> + *
>> + * @iter An iterator name.  Scoped is within the loop only.
>> + * @val  A scalar value to iterate over.
>> + *
>> + * A copy of @val is taken internally.
>> + */
>> +#define for_each_set_bit(iter, val)                     \
>> +    for ( typeof(val) __v = (val); __v; )               \
>> +        for ( unsigned int (iter);                      \
>> +              __v && ((iter) = ffs_g(__v) - 1, true);   \
> ... affects what effect the "- 1" here has.

Yes, it was this.

After fixing the bracketing, everything is green. 
https://gitlab.com/xen-project/people/andyhhp/xen/-/pipelines/1349243540

~Andrew