From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: [PATCH] x86: mark BUG()s and assertion failures as terminal. Date: Thu, 19 Sep 2013 15:39:46 +0100 Message-ID: <1379601586-27173-1-git-send-email-tim@xen.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: keir@xen.org, jbeulich@suse.com List-Id: xen-devel@lists.xenproject.org This helps avoid static analysis false-positives, and might lead to better code density as the compiler knows it doesn't have to restore spilled state &c. Signed-off-by: Tim Deegan --- xen/include/asm-x86/bug.h | 11 ++++++++--- xen/include/xen/compiler.h | 6 ++++++ 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/xen/include/asm-x86/bug.h b/xen/include/asm-x86/bug.h index e5dd559..956bfd2 100644 --- a/xen/include/asm-x86/bug.h +++ b/xen/include/asm-x86/bug.h @@ -46,12 +46,17 @@ struct bug_frame { #define WARN() BUG_FRAME(BUGFRAME_warn, __LINE__, __FILE__, 0, NULL) -#define BUG() BUG_FRAME(BUGFRAME_bug, __LINE__, __FILE__, 0, NULL) +#define BUG() do { \ + BUG_FRAME(BUGFRAME_bug, __LINE__, __FILE__, 0, NULL); \ + unreachable(); \ +} while (0) #define run_in_exception_handler(fn) BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, NULL) -#define assert_failed(msg) \ - BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg) +#define assert_failed(msg) do { \ + BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg); \ + unreachable(); \ +} while (0) extern const struct bug_frame __start_bug_frames[], __stop_bug_frames_0[], diff --git a/xen/include/xen/compiler.h b/xen/include/xen/compiler.h index 7009a09..7d6805c 100644 --- a/xen/include/xen/compiler.h +++ b/xen/include/xen/compiler.h @@ -14,6 +14,12 @@ #define always_inline __inline__ __attribute__ ((always_inline)) #define noinline __attribute__((noinline)) +#if (!defined(__clang__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 5)) +#define unreachable() do {} while (1) +#else +#define unreachable() __builtin_unreachable() +#endif + #ifdef __clang__ /* Clang can replace some vars with new automatic ones that go in .data; * mark all explicit-segment vars 'used' to prevent that. */ -- 1.7.10.4