Quoting Nicolai Hähnle (2018-12-18 09:37:43)
> On 17.12.18 23:46, Dylan Baker wrote:
> > Quoting Marek Olšák (2018-12-17 12:25:29)
> >> On Mon, Dec 17, 2018 at 1:18 PM Eric Anholt <e...@anholt.net> wrote:
> >>
> >> Eero Tamminen <eero.t.tammi...@intel.com> writes:
> >>
> >> > Hi,
> >> >
> >> > On 17.12.2018 8.08, Marek Olšák wrote:
> >> > [...]
> >> >> I think one of the serious usability issues is that environment
> >> >> variables such as CFLAGS, CXXFLAGS, LDFLAGS, and PKG_CONFIG_PATH
> >> are not
> >> >> saved by meson for future reconfigures.
> >> >
> >> > I don't know what Meson is supposed to do, but to me that would be
> >> > a bug in a build tool.
> >> >
> >> > Re-configure is supposed to adapt SW to the changes in the build
> >> > environment, and environment variables are part of that (along with
> >> > command line options and SW installed to to the system). Build
> >> > configure tool deciding to "remember" some of those things instead
> >> > of checking the new situation, seems like a great opportunity for
> >> > confusion.
> >>
> >> A user-triggered reconfigure, sure. Recapture env vars then. But
> >> "git
> >> pull; ninja -C build" losing track of the configuration state is
> >> broken.
> >> We don't have to specify all of your meson -Doption=state
> >> configuration
> >> on every build, why should you need to specify your PKG_CONFIG_PATH
> >> configure options on every build?
> >>
> >>
> >> Thanks, Eric.
> >>
> >> Yes, meson behaves such that users have to set all environment variables
> >> for
> >> every "ninja" command that might reconfigure.
> >>
> >> I see 2 solutions:
> >> 1) meson needs to remember the relevant env vars
> >> 2) meson should FAIL to configure if any of the env vars are set (if it
> >> wants
> >> to ignore them)
> >>
> >> Marek
> >
> > Meson does remember the *_FLAGS variables. Those are translated on configure
> > into meson's internal ${lang}_args and ${lang}_link args. It does look like
> > those aren't remembered when --wipe is called though, I filed a bug for
> > that:
> > https://github.com/mesonbuild/meson/issues/4650
>
> I ran into this same problem and noticed that Meson is already able to
> *warn* about such changes.
>
> It should either ignore the changes, or better yet, fail.
>
> (Or even better: ignore environment variables entirely; IMO sourcing the
> environment implicitly in a build system with an explicit configure is
> just a broken design that was unfortunately inherited from plain make
> without really considering the UI implications.)I agree with this, as do most of the upstream meson developers. So do the autotools developers, who recommend passing CFLAGS (and friends) as arguments instead of as env variables: ./configure CFLAGS='-march=native -03' LDFLAGS='-O3' --enable-foo meson supports this using: meson -Dc_args='-march-native' -Dc_link_args='-O3' -Dfoo=true Meson basically inherited this from autotools, and in hindsight we shouldn't have. I'm going to do 3 things I think: - Update our documentation to strongly recommend -Dc_args and not CLFAGS - Push for meson to warn about using environment variables and recommend command line options. - Push for meson to remove CFLAGS and friends support: https://github.com/mesonbuild/meson/issues/4664 Dylan
signature.asc
Description: signature
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
