From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:44908) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1giz57-0005ii-HC for qemu-devel@nongnu.org; Mon, 14 Jan 2019 05:02:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1giz56-0007cl-87 for qemu-devel@nongnu.org; Mon, 14 Jan 2019 05:02:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34544) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1giz56-0007cU-2o for qemu-devel@nongnu.org; Mon, 14 Jan 2019 05:02:56 -0500 From: Thomas Huth Date: Mon, 14 Jan 2019 11:02:16 +0100 Message-Id: <1547460140-1473-22-git-send-email-thuth@redhat.com> In-Reply-To: <1547460140-1473-1-git-send-email-thuth@redhat.com> References: <1547460140-1473-1-git-send-email-thuth@redhat.com> Subject: [Qemu-devel] [PULL 21/25] linux-user: Fix compilation with clang 3.4 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , qemu-devel@nongnu.org Cc: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Li Qiang Clang version 3.4.2 does not know the -Wpragmas option yet and bails out with an error when we try to disable it in linux-user/qemu.h. Fortunately, clang has a __has_warning() macro which allows us to add an explicit check for the option that we want to ignore. With that we can check for the availability of "-Waddress-of-packed-member" properly and do not need the "-Wpragmas" at all here. Fixes: 850d5e330a9c68cc998cecc02caf8a3c8d1ee8a3 Reviewed-by: Laurent Vivier Signed-off-by: Thomas Huth --- include/qemu/compiler.h | 4 ++++ linux-user/qemu.h | 6 +----- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index 261842b..28fa438 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -113,6 +113,10 @@ #define GCC_FMT_ATTR(n, m) #endif +#ifndef __has_warning +#define __has_warning(x) 0 /* compatibility with non-clang compilers */ +#endif + #ifndef __has_feature #define __has_feature(x) 0 /* compatibility with non-clang compilers */ #endif diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 069df8f..ef400cb 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -474,17 +474,13 @@ static inline int access_ok(int type, abi_ulong addr, abi_ulong size) * functions than host-endian unaligned load/store plus tswapN. * - The pragmas are necessary only to silence a clang false-positive * warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 . - * - We have to disable -Wpragmas warnings to avoid a complaint about - * an unknown warning type from older compilers that don't know about - * -Waddress-of-packed-member. * - gcc has bugs in its _Pragma() support in some versions, eg * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only * include the warning-suppression pragmas for clang */ -#ifdef __clang__ +#if defined(__clang__) && __has_warning("-Waddress-of-packed-member") #define PRAGMA_DISABLE_PACKED_WARNING \ _Pragma("GCC diagnostic push"); \ - _Pragma("GCC diagnostic ignored \"-Wpragmas\""); \ _Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"") #define PRAGMA_REENABLE_PACKED_WARNING \ -- 1.8.3.1