Date: Sun, 21 Jun 2026 11:11:19 -0700 From: Mark Millard <marklmi@yahoo.com> To: Warner Losh <imp@FreeBSD.org>, src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Cc: Faraz Vahedi <kfv@kfv.io>, Nuno Teixeira <eduardo@freebsd.org> Subject: Re: git: 28cecfe27964 - main - libc: Restrict ATOMIC_VAR_INIT for C23 conformance Message-ID: <4e902fcf-e79c-47b5-a51f-4881c09f7528@yahoo.com> In-Reply-To: <6a35ddd3.22963.721d614@gitrepo.freebsd.org>
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On 6/19/26 17:24, Warner Losh wrote: > The branch main has been updated by imp: > > URL: https://cgit.FreeBSD.org/src/commit/?id=28cecfe27964fdb67497800f5dcd5d3e1033727f > > commit 28cecfe27964fdb67497800f5dcd5d3e1033727f > Author: Faraz Vahedi <kfv@kfv.io> > AuthorDate: 2026-05-01 14:34:44 +0000 > Commit: Warner Losh <imp@FreeBSD.org> > CommitDate: 2026-06-20 00:23:28 +0000 > > libc: Restrict ATOMIC_VAR_INIT for C23 conformance > > Omit `ATOMIC_VAR_INIT` when targeting C23, where it has been removed. > Retain it for earlier C standards and for C++ (as it still remains in > C++23, albeit marked as deprecated since C17 and C++20.) > > Also separate `atomic_init` definitions from `ATOMIC_VAR_INIT` to > avoid coupling with a deprecated initialisation mechanism. > > No functional change intended for `atomic_init`; this is purely a > conformance and cleanup adjustment. > > Signed-off-by: Faraz Vahedi <kfv@kfv.io> > Reviewed by: imp > Pull Request: https://github.com/freebsd/freebsd-src/pull/2185 > --- > sys/sys/stdatomic.h | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/sys/sys/stdatomic.h b/sys/sys/stdatomic.h > index c3f9b217519c..2d565ce991be 100644 > --- a/sys/sys/stdatomic.h > +++ b/sys/sys/stdatomic.h > @@ -86,11 +86,17 @@ > * 7.17.2 Initialization. > */ > > +#if __ISO_C_VISIBLE < 2023 || defined(__cplusplus) > #if defined(__CLANG_ATOMICS) > #define ATOMIC_VAR_INIT(value) (value) > -#define atomic_init(obj, value) __c11_atomic_init(obj, value) > #else > #define ATOMIC_VAR_INIT(value) { .__val = (value) } > +#endif > +#endif > + > +#if defined(__CLANG_ATOMICS) > +#define atomic_init(obj, value) __c11_atomic_init(obj, value) > +#else > #define atomic_init(obj, value) ((void)((obj)->__val = (value))) > #endif > > > I expect that the problem reports for port package build failures are tied to src/sys/sys/_visible.h : . . . #elif defined(_C23_SOURCE) /* Localism to specify strict C23 env. */ #define __POSIX_VISIBLE 0 #define __XSI_VISIBLE 0 #define __BSD_VISIBLE 0 #define __ISO_C_VISIBLE 2023 #define __EXT1_VISIBLE 0 #else /* Default environment: show everything. */ #define __POSIX_VISIBLE 202405 #define __XSI_VISIBLE 800 #define __BSD_VISIBLE 1 #define __ISO_C_VISIBLE 2023 #define __EXT1_VISIBLE 1 #endif #endif /* _POSIX_C_SOURCE */ The "show everything" note is wrong now, as C23 removes at least ATOMIC_VAR_INIT . A real "show everything" would require more logic, such as still keeping ATOMIC_VAR_INIT for __BSD_VISIBLE also being 1 or some such (may be inventing a new configuration macro for, say, __ISO_C_BUT_WITHOUT_SOME_REMOVALS). -- === Mark Millard marklmi at yahoo.comhome | help
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