Re: [PATCH] Update scripts/meson-buildoptions.sh

[Stefan Hajnoczi]

On Tue, 3 Jan 2023 at 12:31, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On Tue, 3 Jan 2023 at 16:12, Alessandro Di Federico <ale@rev.ng> wrote:
> >
> > On Tue, 3 Jan 2023 10:51:36 -0500
> > Stefan Hajnoczi <stefanha@gmail.com> wrote:
> >
> > > QEMU's Makefile used to a use a technique where it generated
> > > "timestamp" files and used cmp(1) to check if rebuilding was
> > > necessary:
> > > 1. Always generate meson-buildoptions.sh-timestamp.
> >
> > `meson-buildoptions.sh-timestamp` would be the full expected output,
> > right? It's not just a date or something.
> > AFAIU that would make sure that if nothing changed in the output you
> > don't trigger other targets depending on `meson-buildoptions.sh`. It's
> > a solution for a different problem.
> >
> > The problem with always rebuilding `meson-buildoptions.sh` is that we
> > spend 1 extra second on every build, even those that doesn't need to
> > rebuild anything else.
> > Not unacceptable, but I think we should strive not to commit generated
> > files and move the file to the build directory, unless there's a reason
> > why this is not viable that I'm not seeing.
>
> The other problem with this file is that it appears to
> be generated differently depending on the host distro
> (specifically the default value for the --libdir option).
> That also would seem to nudge towards "don't commit a
> generated file".

Paolo: Is the meson-buildoptions.sh approach a temporary solution or
something long-term? Maybe everything can be migrated to meson
eventually so that ./configure and meson-buildoptions.sh are no longer
necessary?

Stefan