clang 13 and __STDC_NO_ATOMICS__ (was: Re: LLVM 13 ports build failures (2021-10-27))

On Thu, Oct 28 2021, Christian Weisgerber <naddy@mips.inka.de> wrote:
> I ran an amd64 bulk build with base clang updated to LLVM 13.
>
> There is substantial fallout. Java appears to be broken and there
> are numerous failures caused by clang 13 issuing new warnings and
> ports using -Werror.
>
> Failure logs:
> http://build-failures.rhaalovely.net/amd64-clang/2021-10-27/
>
> The final error may be misleading. For instance, devel/libdsm fails
> with a linker error "undefined reference to pthread_create", but
> the root cause is -Werror breaking a configure check.
>
> Below there's a list of affected ports. Several hundred more weren't
> built because they depend on something that failed.
>
> audio/cmus

jsg@ pointed out that this new clang defines __STDC_NO_ATOMICS__
which is most likely wrong. This breaks at least cmus:

http://build-failures.rhaalovely.net/amd64-clang/2021-10-27/audio/cmus.log

--
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE