From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:48101) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ghGtW-0000Jr-9Y for qemu-devel@nongnu.org; Wed, 09 Jan 2019 11:39:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ghGtV-0005B7-Fm for qemu-devel@nongnu.org; Wed, 09 Jan 2019 11:39:54 -0500 From: Thomas Huth Date: Wed, 9 Jan 2019 17:39:36 +0100 Message-Id: <1547051976-13982-3-git-send-email-thuth@redhat.com> In-Reply-To: <1547051976-13982-1-git-send-email-thuth@redhat.com> References: <1547051976-13982-1-git-send-email-thuth@redhat.com> Subject: [Qemu-devel] [PATCH v3 2/2] configure: Force the C standard to gnu99 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Richard Henderson , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , pbonzini@redhat.com, peter.maydell@linaro.org, Markus Armbruster , qemu-ppc@nongnu.org Different versions of GCC and Clang use different versions of the C standard. This repeatedly caused problems already, e.g. with duplicated typedefs: https://lists.gnu.org/archive/html/qemu-devel/2018-11/msg05829.html or with for-loop variable initializers: https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg00237.html To avoid these problems, we should enforce the C language version to the same level for all compilers. Since our minimum compiler versions is GCC v4.8, our best option is "gnu99" for C code right now ("gnu17" is not available there yet, and "gnu11" is marked as "experimental"), and "gnu++98" for the few C++ code that we have in the repository. Signed-off-by: Thomas Huth --- v3: Compile C++ code with -std=gnu++98 configure | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/configure b/configure index b9f34af..448dbc8 100755 --- a/configure +++ b/configure @@ -107,6 +107,9 @@ update_cxxflags() { -Wstrict-prototypes|-Wmissing-prototypes|-Wnested-externs|\ -Wold-style-declaration|-Wold-style-definition|-Wredundant-decls) ;; + -std=gnu99) + QEMU_CXXFLAGS=${QEMU_CXXFLAGS:+$QEMU_CXXFLAGS }"-std=gnu++98" + ;; *) QEMU_CXXFLAGS=${QEMU_CXXFLAGS:+$QEMU_CXXFLAGS }$arg ;; @@ -585,7 +588,7 @@ ARFLAGS="${ARFLAGS-rv}" # left shift of signed integers is well defined and has the expected # 2s-complement style results. (Both clang and gcc agree that it # provides these semantics.) -QEMU_CFLAGS="-fno-strict-aliasing -fno-common -fwrapv $QEMU_CFLAGS" +QEMU_CFLAGS="-fno-strict-aliasing -fno-common -fwrapv -std=gnu99 $QEMU_CFLAGS" QEMU_CFLAGS="-Wall -Wundef -Wwrite-strings -Wmissing-prototypes $QEMU_CFLAGS" QEMU_CFLAGS="-Wstrict-prototypes -Wredundant-decls $QEMU_CFLAGS" QEMU_CFLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $QEMU_CFLAGS" -- 1.8.3.1