From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45662) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WYHsR-00024G-O6 for qemu-devel@nongnu.org; Thu, 10 Apr 2014 12:31:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WYHsM-0000fp-I6 for qemu-devel@nongnu.org; Thu, 10 Apr 2014 12:30:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:24672) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WYHsL-0000fj-T6 for qemu-devel@nongnu.org; Thu, 10 Apr 2014 12:30:54 -0400 Date: Thu, 10 Apr 2014 19:31:32 +0300 From: "Michael S. Tsirkin" Message-ID: <20140410163132.GA28144@redhat.com> References: <1397041487-28477-1-git-send-email-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1397041487-28477-1-git-send-email-peter.maydell@linaro.org> Subject: Re: [Qemu-devel] [PATCH for-2.0] configure: use do_cc when checking for -fstack-protector support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Paolo Bonzini , Andreas =?iso-8859-1?Q?F=E4rber?= , Steven Noonan , qemu-devel@nongnu.org, patches@linaro.org On Wed, Apr 09, 2014 at 12:04:47PM +0100, Peter Maydell wrote: > MacOSX clang silently swallows unrecognized -f options when doing a link > with '-framework' also on the command line, so to detect support for > the various -fstack-protector options we must do a plain .c to .o compile, > not a complete compile-and-link. > > Signed-off-by: Peter Maydell Hmm it worries me a bit that we aren't passing it to linker: might break some builds in case compiler has a working protector but linker doesn't. How about checking both do_cc and compile_prog here? > --- > This should be a pretty safe change and it prevents clang/MacOSX > builds from spewing a warning on every C file compilation, so I'd > like to get it into 2.0. > > configure | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/configure b/configure > index eb0e7bb..c85475f 100755 > --- a/configure > +++ b/configure > @@ -1448,7 +1448,7 @@ done > if test "$stack_protector" != "no" ; then > gcc_flags="-fstack-protector-strong -fstack-protector-all" > for flag in $gcc_flags; do > - if compile_prog "-Werror $flag" "" ; then > + if do_cc $QEMU_CFLAGS -Werror $flag -c -o $TMPO $TMPC ; then > QEMU_CFLAGS="$QEMU_CFLAGS $flag" > LIBTOOLFLAGS="$LIBTOOLFLAGS -Wc,$flag" > break > -- > 1.8.5.4 > Long term we might want this: But I'm not sure it's a good idea to make this change so late. --> configure: check -c each time we run compiler Some warnings/errors only surface if you run compiler without a linker. Run both on each test. Signed-off-by: Michael S. Tsirkin diff --git a/configure b/configure index eb0e7bb..8adc72b 100755 --- a/configure +++ b/configure @@ -102,6 +102,7 @@ compile_object() { compile_prog() { local_cflags="$1" local_ldflags="$2" + do_cc $QEMU_CFLAGS -c $local_cflags -o $TMPO $TMPC do_cc $QEMU_CFLAGS $local_cflags -o $TMPE $TMPC $LDFLAGS $local_ldflags }