From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60465) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cYhpT-000488-9c for qemu-devel@nongnu.org; Tue, 31 Jan 2017 18:27:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cYhpS-0001dx-6m for qemu-devel@nongnu.org; Tue, 31 Jan 2017 18:27:15 -0500 Sender: Paolo Bonzini From: Paolo Bonzini References: <1485879287-12548-1-git-send-email-peter.maydell@linaro.org> <20170131165557.GE20303@redhat.com> Message-ID: Date: Tue, 31 Jan 2017 18:27:01 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] Drop QEMU_GNUC_PREREQ() checks for gcc older than 4.1 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , "Daniel P. Berrange" Cc: QEMU Developers , QEMU Trivial , "patches@linaro.org" On 31/01/2017 11:58, Peter Maydell wrote: > On 31 January 2017 at 16:55, Daniel P. Berrange wrote: >> On Tue, Jan 31, 2017 at 04:14:47PM +0000, Peter Maydell wrote: >>> We already require gcc 4.1 or newer (for the atomic >>> support), so the fallback codepaths for older gcc >>> versions than that are now dead code and we can >>> just delete them. >> >> Do we have any explicit check alreadu for 4.1, or do we >> just let the build fail on the atomic code ? >> >> IOW, is there any use in having.. >> >> #if !QEMU_GNUC_PREREQ(4, 1) >> # error "QEMU requires GCC >= 4.1 or CLang" >> #endif > > I guess we just barf in the atomics. An explicit check might > not be a bad idea I guess, though it depends a bit on how > many releases we've been implicitly requiring 4.1 for. I > suppose it would act as documentation of our current > minimum req. We have: - first occurrence on Linux hosts: 0.13.0 (for vhost) - first occurrence on non-Linux hosts: 0.15.0 (simpletrace backend), then backed out in 1.0 - next occurrence on all hosts, but only in tests: 1.4.0 - finally, first occurrence on all hosts with simple ./configure && make: 2.0.0 Paolo