Re: Meson build

On a Tuesday in 2020, Pavel Hrdina wrote: > On Tue, Sep 01, 2020 at 03:13:39PM +0200, Ján Tomko wrote: > > On a Tuesday in 2020, Pavel Hrdina wrote: > > > On Sun, Aug 30, 2020 at 02:34:56AM +0200, Toolybird wrote: > > > > Hi, > > > > > > > > Just a heads up on my experiences with the new build system. > > > > > > > > Arch Linux > > > > meson-0.55.1 > > > > > > > > Overall, it looks good, so well done! > > > > > > > > Just a couple of minor things I noted: > > > > > > > > 1. Arch uses a meson wrapper script (arch-meson) that sets: > > > > > > > >   --buildtype plain > > > > > > > > This seems to trigger a bug in meson that results in copious bogus compiler warnings: > > > > > > > > cc1: warning: ‘-Wformat-y2k’ ignored without ‘-Wformat’ [-Wformat-y2k] > > > > cc1: warning: ‘-Wformat-extra-args’ ignored without ‘-Wformat’ [-Wformat-extra-args] > > > > cc1: warning: ‘-Wformat-zero-length’ ignored without ‘-Wformat’ [-Wformat-zero-length] > > > > cc1: warning: ‘-Wformat-contains-nul’ ignored without ‘-Wformat’ [-Wformat-contains-nul] > > > > cc1: warning: ‘-Wformat-security’ ignored without ‘-Wformat’ [-Wformat-security] > > > > > > > > which of course breaks -Werror builds. > > > > > > > > I can easily work around it by setting `-D git_werror=disabled' or even better still: > > > > > > > > CFLAGS+=" -Wall" arch-meson... > > > > > > This should be easily fixable by adding -Wformat in our list of flags > > > that we pass to compiler. We were incorrectly relying on meson to add > > > -Wformat automatically and since we add the other -Wformat* flags > > > manually we should add -Wformat as well. I'll post a patch to fix this. > > > > > > > What would that fix? > > > > It would neither be a plain build, nor a full -Werror build (since we're > > missing -Wall). > > It would fix building libvirt from git in case user uses > buildtype=plain. > For a build from git, we expect people to build with all the warnings and -Werror. Per your comment in the below issue: https://github.com/mesonbuild/meson/issues/7399#issuecomment-684856012 meson does not add the warnings there on purpose. The combination of disabling the most important warnings and enabling just the extras doesn't make much sense. Especially if we still pretend it's a -Werror build.