Re: x86: generate template sets data at build time

[Jan Beulich <jbeulich@suse.com>]

On 14.12.2022 06:14, Alan Modra wrote:
>> +    /* Type checks to compensate for the conversion through void * which
>> +       occurs during hash table insertion / lookup.  */
>> +    (void)(sets == &current_templates->start);
>> +    (void)(end == &current_templates->end);
> 
> This results in asan complaining about "member access within null
> pointer of type 'const templates'".

Interesting. How can it know that current_templates is still NULL?
(I guess one can't expect it to realize that with the cast to void
this doesn't really stand a chance of exhibiting UB; technically
the compiler _may_ generate code for this nevertheless, and that
code _may_ do anything due to it being UB.) It's also not clear to
me what to do to work around the issue: Assign to current_templates
instead, followed by assigning back NULL after the checks? (This
would feel like clutter to me.) Are there other "standard" ways of
working around such border line asan complaints?

Jan