From c3e2c873ffa8e89b5f83dccc4e4e35dfcea633cb Mon Sep 17 00:00:00 2001 From: Khem Raj Date: Sat, 14 Jan 2023 12:39:43 -0800 Subject: Define _DBUS_ALIGNOF using _Alignof when using C11 or newer WG14 N2350 made very clear that it is an UB having type definitions within "offsetof" [1]. This patch changes the implementation of macro _DBUS_ALIGNOF to builtin "_Alignof" to avoid undefined behavior. clang 16+ has started to diagnose this [2] Fixes build when using -std >= gnu11 and using clang16+ [1] https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm [2] https://reviews.llvm.org/D133574 Signed-off-by: Khem Raj --- dbus/dbus-internals.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'dbus') diff --git a/dbus/dbus-internals.h b/dbus/dbus-internals.h index cc98c92a..2387752d 100644 --- a/dbus/dbus-internals.h +++ b/dbus/dbus-internals.h @@ -201,8 +201,12 @@ void _dbus_real_assert_not_reached (const char *explanation, ((intptr_t) ((unsigned char*) &((struct_type*) 0)->member)) #endif +#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L && !defined(__cplusplus) +#define _DBUS_ALIGNOF(type) _Alignof(type) +#else #define _DBUS_ALIGNOF(type) \ (_DBUS_STRUCT_OFFSET (struct { char _1; type _2; }, _2)) +#endif #if defined(DBUS_DISABLE_CHECKS) || defined(DBUS_DISABLE_ASSERT) /* this is an assert and not an error, but in the typical --disable-checks case (you're trying -- cgit v1.2.1