| From c3e2c873ffa8e89b5f83dccc4e4e35dfcea633cb Mon Sep 17 00:00:00 2001 |
| From: Khem Raj <raj.khem@gmail.com> |
| Date: Sat, 14 Jan 2023 12:39:43 -0800 |
| Subject: [PATCH] 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 |
| |
| Upstream-Status: Submitted [https://gitlab.freedesktop.org/dbus/dbus/-/merge_requests/389] |
| Signed-off-by: Khem Raj <raj.khem@gmail.com> |
| --- |
| dbus/dbus-internals.h | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| 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 |
| -- |
| 2.39.0 |
| |