From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:60065)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <i.mitsyanko@gmail.com>) id 1TSUOt-0002iB-53
	for qemu-devel@nongnu.org; Sun, 28 Oct 2012 11:03:44 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <i.mitsyanko@gmail.com>) id 1TSUOs-0004yt-3G
	for qemu-devel@nongnu.org; Sun, 28 Oct 2012 11:03:43 -0400
Received: from mail-lb0-f173.google.com ([209.85.217.173]:54688)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <i.mitsyanko@gmail.com>) id 1TSUOr-0004ye-Rx
	for qemu-devel@nongnu.org; Sun, 28 Oct 2012 11:03:42 -0400
Received: by mail-lb0-f173.google.com with SMTP id gj3so2486249lbb.4
	for <qemu-devel@nongnu.org>; Sun, 28 Oct 2012 08:03:40 -0700 (PDT)
Message-ID: <508D4945.4050500@gmail.com>
Date: Sun, 28 Oct 2012 19:03:33 +0400
From: Igor Mitsyanko <i.mitsyanko@gmail.com>
MIME-Version: 1.0
References: <1351372747-15992-1-git-send-email-peter.maydell@linaro.org>
In-Reply-To: <1351372747-15992-1-git-send-email-peter.maydell@linaro.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH] configure: use -Wwombat to test whether
 gcc recognizes -Wno-wombat
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Blue Swirl <blauwirbel@gmail.com>, Stefan Weil <sw@weilnetz.de>, qemu-devel@nongnu.org, patches@linaro.org

On 10/28/2012 1:19 AM, Peter Maydell wrote:
> gcc will silently accept unrecognized -Wno-wombat warning suppression
> options (it only mentions them if it has to print a compiler warning
> for some other reason). Since we already run a check for whether gcc
> recognizes the warning options we use, we can easily make this use
> the positive sense of the option when checking for support for the
> suppression option. This doesn't have any effect except that it avoids
> gcc emitting extra messages about unrecognized command line options
> when it is printing other warning messages.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   configure | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/configure b/configure
> index 37f712d..4c2ba06 100755
> --- a/configure
> +++ b/configure
> @@ -1169,7 +1169,11 @@ cat > $TMPC << EOF
>   int main(void) { return 0; }
>   EOF
>   for flag in $gcc_flags; do
> -    if compile_prog "-Werror $flag" "" ; then
> +    # Use the positive sense of the flag when testing for -Wno-wombat
> +    # support (gcc will happily accept the -Wno- form of unknown
> +    # warning options).
> +    optflag="$(echo $flag | sed -e 's/^-Wno-/-W/')"
> +    if compile_prog "-Werror $optflag" "" ; then
>   	QEMU_CFLAGS="$QEMU_CFLAGS $flag"
>       fi
>   done
>

Reviewed-by: Igor Mitsyanko <i.mitsyanko@samsung.com>