[FFmpeg-devel] [PATCH] configure: make the check for stdatomic.h stricter

[Moritz Barsnick]

On Tue, Dec 27, 2016 at 21:55:42 -0300, James Almer wrote:
> ICC stdatomic.h implementation seems to be incomplete or broken,
> missing the ATOMIC_VAR_INIT() macro.
> 
> Should fix ticket #6049

Your patch works for me with ICC 14.0.3. I'm the reporter of #6049.

But see this:
https://software.intel.com/en-us/articles/c11-support-in-intel-c-compiler

ICC may have the stdatomic.h header and have some of the features, but
doesn't actually advertise them (__STDC_VERSION__) before their
(somewhat) complete implementation in ICC 16. Same situation with gcc
before 4.7, I guess. Perhaps the check for __STDC_VERSION__ == 201112L
would "guarantee" the proper availability of atomics (would need to be
verified on all sorts of compilers), but I guess your check for the
actually used features is more to the point. Is that check complete
though?

Moritz