Re: [Qemu-devel] [RFC] Enable Werrror by default

[Mark McLoughlin <markmc@redhat.com>]

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 locally 
> for a while now, and it's been extremely useful in picking up dumb errors 
> (like the recent stellaris_enet.c breakage).
> 
> Any objections?
> 
> You can of course configure with --disable-werror if you really want the force 
> things to build.

Based on experiences with other projects:

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

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

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

  4) It's debatable whether builds from git should default to -Werror - 
     on the plus side it helps ensure (2) happens, on the minus side if 
     a warning does sneak in, it makes life a pain for everyone until a 
     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: ‘blkcfg.size_max’ is used uninitialized in this function