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Re: stdatomic.h and atomic_load_explicit()

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.

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__.

Sebastian Huber, embedded brains GmbH

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