From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:60926) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1rDZ-0002eT-RL for qemu-devel@nongnu.org; Thu, 07 Mar 2019 06:29:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h1rDY-0007ep-ST for qemu-devel@nongnu.org; Thu, 07 Mar 2019 06:29:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53520) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h1rDY-0007eS-JS for qemu-devel@nongnu.org; Thu, 07 Mar 2019 06:29:40 -0500 Date: Thu, 7 Mar 2019 11:29:33 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20190307112933.GA2853@work-vm> References: <3246431b-8d6e-f2bc-e0f0-99d80384d97b@redhat.com> <9fb589af-a78e-6eeb-ca1c-a5049c5ac5ab@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] converting build system to Meson? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Thomas Huth , Paolo Bonzini , Richard Henderson , qemu-devel , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau * Peter Maydell (peter.maydell@linaro.org) wrote: > On Thu, 7 Mar 2019 at 06:39, Thomas Huth wrote: > > On 06/03/2019 19.12, Paolo Bonzini wrote: > > > lately I have been thinking of converting the QEMU build system to > > > Meson. Meson is a relatively new build system that can replace > > > Autotools or hand-written Makefiles such as QEMU; as a die-hard > > > Autotools fan, I must say that Meson is by far better than anything else > > > that has ever tried to replace Autotools, and actually has the potential > > > to do so. > > > > > > Advantages of Meson that directly matter for QEMU include:[...] > > > > I'm not objecting a new build system per se, but could you elaborate on > > problems of the current QEMU build system that will be fixed by this > > change? Since apart from some minor glitches (with the *.mak file > > dependencies for example), the current build system seems to work quite > > well for me ... so at least I currently don't feel enough pain yet to do > > such a big step, just because there is another new cool build system > > around... > > Yes, that tends to be my view. Our current build system: > * has no dependencies that are problematic for older hosts > (contrast Meson, which needs Python 3.5, even if we take > the drastic step of shipping an entire build tool along > with QEMU; OSX python is 2.7 still) > * is not particularly hard to deal with for the common cases > ("add new source file" is straightforward) > * covers all our requirements as far as I'm aware > (whereas you've listed a couple of places where Meson > would need changes/extensions to support things we do already) > * is generally flexible enough to be hackable to deal with odd > cases (it has escape mechanisms to generic-programmability, > even if they're ugly and awkward) Pretty regularly I just give up on build directories and recreate them because of changes that our Makefiles haven't realised when updating a tree. (I can't say it's any one fault anywhere) Having said that, the counterpoint in Meson is that it's build directories seem tobe exact-meson version dependent; doing a minor host update and you find you have to nuke your build directories. Dave > So I think we'd need a more compelling reason to move right now. > (This might change in the future, eg if Meson catches on to the > extent that everybody is using it and competitors like CMake are > more obviously eclipsed by it, in the way that git took over > from svn and relegated mercurial and bzr to obscurity.) > > thanks > -- PMM > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK