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Subject: Re: [Qemu-devel] [RFC] Enable Werrror by default
From: Mark McLoughlin <markmc@redhat.com>
In-Reply-To: <200906111335.10116.paul@codesourcery.com>
References: <200906111335.10116.paul@codesourcery.com>
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Date: Thu, 11 Jun 2009 14:14:46 +0100
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To: Paul Brook <paul@codesourcery.com>
Cc: qemu-devel@nongnu.org

On Thu, 2009-06-11 at 13:35 +0100, Paul Brook wrote:

> I'd like to enable Werror by default. I've been using --enable-werror l=
ocally=20
> for a while now, and it's been extremely useful in picking up dumb erro=
rs=20
> (like the recent stellaris_enet.c breakage).
>=20
> Any objections?
>=20
> You can of course configure with --disable-werror if you really want th=
e force=20
> things to build.

Based on experiences with other projects:

  1) Release tarballs should not ship with -Werror on by default - e.g.=20
     new gcc comes along with new warnings and the tarball build fails=20
     with no benefit to anyone

  2) Anyone submitting patches should build with -Werror and make sure=20
     they don't introduce new warnings

  3) People with newer gcc are likely to be tripped up by warnings=20
     introduced by others with older gcc[1]

  4) It's debatable whether builds from git should default to -Werror -=20
     on the plus side it helps ensure (2) happens, on the minus side if=20
     a warning does sneak in, it makes life a pain for everyone until a=20
     fix gets applied

IMHO, we should enable it by default for git builds.

Cheers,
Mark.

[1] e.g. with gcc-4.4.0, but not with gcc-4.3.2:

  hw/virtio-blk.c:302: warning: =E2=80=98blkcfg.size_max=E2=80=99 is used=
 uninitialized in this function