Re: git: 28cecfe27964 - main - libc: Restrict ATOMIC_VAR_INIT for C23 conformance

Reply: Nuno Teixeira : "Re: git: 28cecfe27964 - main - libc: Restrict ATOMIC_VAR_INIT for C23 conformance"
In reply to: Warner Losh : "git: 28cecfe27964 - main - libc: Restrict ATOMIC_VAR_INIT for C23 conformance"
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From: Nuno Teixeira <eduardo_at_freebsd.org>
Date: Sun, 21 Jun 2026 10:35:01 UTC
Hello,

(poudriere-devel build at main-n286792-eafa181d51f7: Sat Jun 20)

I've found that ports-mgmt/portfmt started failing with:
...
FAILED: [code=1]
/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/_build/portscan/status.o
cc -std=gnu11 -O2 -g -W -Wall -Wextra -Wmissing-prototypes
-Wstrict-prototypes -Wwrite-strings -Wno-unused-parameter -flto=thin -O2
-pipe  -fstack-protector-strong -fno-strict-aliasing
 -Wno-strict-prototypes  -DPORTFMT_SUBPACKAGES=0 -MD -MF
/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/_build/portscan/status.o.d
-I/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/_build
-I/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6 -c -o
/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/_build/portscan/status.o
/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/portscan/status.c
/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/portscan/status.c:59:38:
warning: call to undeclared function 'ATOMIC_VAR_INIT'; ISO C99 and later
do not support implicit function declarations
[-Wimplicit-function-declaration]
   59 | static atomic_int status_requested = ATOMIC_VAR_INIT(0);
      |                                      ^
/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/portscan/status.c:59:38:
error: initializer element is not a compile-time constant
   59 | static atomic_int status_requested = ATOMIC_VAR_INIT(0);
      |                                      ^~~~~~~~~~~~~~~~~~
/wrkdirs/usr/ports/ports-mgmt/portfmt/work/portfmt-1.1.6/portscan/status.c:60:32:
error: initializer element is not a compile-time constant
   60 | static atomic_size_t scanned = ATOMIC_VAR_INIT(0);
      |                                ^~~~~~~~~~~~~~~~~~
1 warning and 2 errors generated.
...

Same for devel/qt6-base:

...
FAILED: [code=1] src/corelib/CMakeFiles/Core.dir/io/forkfd_qt.c.o
/usr/bin/cc -DBACKTRACE_HEADER=\"execinfo.h\" -DCore_EXPORTS
-DQT_ASCII_CAST_WARNINGS -DQT_BUILDING_QT -DQT_BUILD_CORE_LIB
-DQT_DEPRECATED_WARNINGS -DQT_EXPLICIT_QFILE_CONSTRUCTION_FROM_PATH
-DQT_LEAN_HEADERS=1 -
DQT_MOC_COMPAT -DQT_NO_CAST_TO_ASCII -DQT_NO_CONTEXTLESS_CONNECT
-DQT_NO_DEBUG -DQT_NO_FOREACH -DQT_NO_JAVA_STYLE_ITERATORS
-DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_NO_QASCONST -DQT_NO_QEXCHANGE
-DQT_NO_QPAI
R -DQT_NO_QSNPRINTF -DQT_NO_SINGLE_ARGUMENT_QHASH_OVERLOAD=1
-DQT_NO_STD_FORMAT_SUPPORT -DQT_NO_USING_NAMESPACE -DQT_TYPESAFE_FLAGS
-DQT_USE_NODISCARD_FILE_OPEN -DQT_USE_QSTRINGBUILDER -D_LARGEFILE64_SOURCE
-D_LA
RGEFILE_SOURCE -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_FAST
-I/wrkdirs/usr/ports/devel/qt6-base/work/.build/src/corelib/Core_autogen/include
-I/wrkdirs/usr/ports/devel/qt6-base/work/.build/include -I/wrkd
irs/usr/ports/devel/qt6-base/work/.build/include/QtCore
-I/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib
-I/wrkdirs/usr/ports/devel/qt6-base/work/.build/src/corelib -I/wrkdirs/usr
/ports/devel/qt6-base/work/.build/src/corelib/global
-I/wrkdirs/usr/ports/devel/qt6-base/work/.build/src/corelib/kernel
-I/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/../3rdpart
y/tinycbor/src
-I/wrkdirs/usr/ports/devel/qt6-base/work/.build/include/QtCore/6.11.1
-I/wrkdirs/usr/ports/devel/qt6-base/work/.build/include/QtCore/6.11.1/QtCore
-I/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-ev
erywhere-src-6.11.1/src/corelib/../3rdparty/forkfd
-I/wrkdirs/usr/ports/devel/qt6-base/work/.build/src/corelib/.rcc
-I/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/mkspecs/freebsd-clang
-isy
stem /usr/local/include -isystem /usr/local/include/glib-2.0 -isystem
/usr/local/lib/glib-2.0/include -O2 -pipe  -fstack-protector-strong
-fno-strict-aliasing -pipe  -fstack-protector-strong -fno-strict-aliasing
 -DNDEBUG -O3 -std=gnu11 -fPIC -fvisibility=hidden -Wall -Wextra -pthread
-fcf-protection=full -ftrivial-auto-var-init=pattern
-fstack-protector-strong -fexceptions -MD -MT
src/corelib/CMakeFiles/Core.dir/io/fork
fd_qt.c.o -MF src/corelib/CMakeFiles/Core.dir/io/forkfd_qt.c.o.d -o
src/corelib/CMakeFiles/Core.dir/io/forkfd_qt.c.o -c
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/forkfd_qt
.c
In file included from
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/forkfd_qt.c:16:
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/../../3rdparty/forkfd/forkfd.c:162:39:
warning: call to undeclared function 'ATOMIC_VAR_INIT'; ISO C99 and later
do not support i
mplicit function declarations [-Wimplicit-function-declaration]
  162 | static ffd_atomic_int forkfd_status = FFD_ATOMIC_INIT(0);
      |                                       ^
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/../../3rdparty/forkfd/forkfd_c11.h:54:37:
note: expanded from macro 'FFD_ATOMIC_INIT'
   54 | #define FFD_ATOMIC_INIT(val)        ATOMIC_VAR_INIT(val)
      |                                     ^
In file included from
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/forkfd_qt.c:16:
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/../../3rdparty/forkfd/forkfd.c:162:39:
error: initializer element is not a compile-time constant
  162 | static ffd_atomic_int forkfd_status = FFD_ATOMIC_INIT(0);
      |                                       ^~~~~~~~~~~~~~~~~~
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/../../3rdparty/forkfd/forkfd_c11.h:54:37:
note: expanded from macro 'FFD_ATOMIC_INIT'
   54 | #define FFD_ATOMIC_INIT(val)        ATOMIC_VAR_INIT(val)
      |                                     ^~~~~~~~~~~~~~~~~~~~
In file included from
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/forkfd_qt.c:16:
In file included from
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/../../3rdparty/forkfd/forkfd.c:930:
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/../../3rdparty/forkfd/forkfd_freebsd.c:45:45:
error: initializer element is not a compile-time constant
   45 | static ffd_atomic_int system_forkfd_state = FFD_ATOMIC_INIT(1);
      |                                             ^~~~~~~~~~~~~~~~~~
/wrkdirs/usr/ports/devel/qt6-base/work/qtbase-everywhere-src-6.11.1/src/corelib/io/../../3rdparty/forkfd/forkfd_c11.h:54:37:
note: expanded from macro 'FFD_ATOMIC_INIT'
   54 | #define FFD_ATOMIC_INIT(val)        ATOMIC_VAR_INIT(val)
      |                                     ^~~~~~~~~~~~~~~~~~~~
1 warning and 2 errors generated.
...

Thanks,

Warner Losh <imp@freebsd.org> escreveu (sábado, 20/06/2026 à(s) 01:25):

> 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
>
>
>

-- 
Nuno Teixeira
FreeBSD UNIX:  <eduardo@FreeBSD.org>   Web:  https://FreeBSD.org