stdatomic.h and atomic_load_explicit()

[Sebastian Huber]

On 2014-06-25 15:25, Joseph S. Myers wrote:
> On Wed, 25 Jun 2014, Sebastian Huber wrote:
>
>> I think the inheritance of the volatile qualifier via __typeof__
>> (*__atomic_load_ptr) is an implementation flaw.
>
> See the comment in c_parser_typeof_specifier:
>
>        /* For use in macros such as those in <stdatomic.h>, remove
>           _Atomic and const qualifiers from atomic types.  (Possibly
>           all qualifiers should be removed; const can be an issue for
>           more macros using typeof than just the <stdatomic.h>
>           ones.)  */
>
> (If changing this, remember to change the __auto_type handling as well.)
>

Thanks for the hint.  I sent a patch to the list.

https://gcc.gnu.org/ml/gcc-patches/2014-06/msg02026.html

In case __auto_type discards const and volatile qualifiers, then shouldn't this 
generate a warning (-Wconst-qual)

__auto_type __atomic_load_ptr = (PTR);

?

Why is it necessary to discard the const and/or volatile qualifiers in the 
__auto_type at all?  I think for <stdatomic.h> it should be sufficient to 
discard them only in __typeof__.

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