[Buildroot] [PATCH 1/2] package/pkg-meson.mk: add FOO_MESON_EXTRA_PROPERTIES

[John Keeping]

Hi Peter,

On Tue, 10 Mar 2020 15:07:26 +0100
Peter Seiderer <ps.report at gmx.net> wrote:

> On Tue, 10 Mar 2020 12:44:58 +0000, John Keeping <john at metanate.com> wrote:
> 
> > With autoconf packages, we often specify ac_cv_func_... cached values to
> > avoid runtime checks during configure.  With meson the equivalent is
> > setting properties in cross-compilation.conf which we cannot do in
> > Buildroot at the moment.
> >
> > For example, libglib2 used to set ac_cv_func_printf_unix98 and
> > ac_cv_func_vsnprintf_c99 so that the system printf could be used, but
> > with the conversion to meson these checks fail and the gnulib fallback
> > is used.
> >
> > Add infrastructure in the same way as FOO_MESON_EXTRA_BINARIES to allow
> > per-package modification to the cross-compilation properties.
> >
> > Signed-off-by: John Keeping <john at metanate.com>
> > ---
> >  docs/manual/adding-packages-meson.txt | 8 ++++++++
> >  package/pkg-meson.mk                  | 4 ++++
> >  2 files changed, 12 insertions(+)
> >
> > diff --git a/docs/manual/adding-packages-meson.txt b/docs/manual/adding-packages-meson.txt
> > index e84bf7f60a..c28828243c 100644
> > --- a/docs/manual/adding-packages-meson.txt
> > +++ b/docs/manual/adding-packages-meson.txt
> > @@ -116,6 +116,14 @@ will therefore only use a few of them.
> >    single quotes. By default, empty. Note that Buildroot already sets the
> >    correct values for +c+, +cpp+, +ar+, +strip+, and +pkgconfig+.
> >
> > +* +FOO_MESON_EXTRA_PROPERTIES+, to specify a space-separated list of
> > +  properties to add to the `[properties]` section of the meson
> > +  `cross-compilation.conf` configuration file. The format is
> > +  `property-name='value'`, with no space around the +=+ sign, and with the
> > +  value between single quotes. By default, empty. Note that Buildroot
> > +  already sets values for +needs_exe_wrapper+, +c_args+, +c_link_args+,
> > +  +cpp_args+, +cpp_link_args+, +sys_root+, and +pkg_config_libdir+.
> > +  
> 
> The description does not fit the usage in the follow-up patch
> (...value between single quoates...):
> 
> +LIBGLIB2_MESON_EXTRA_PROPERTIES = \
> +	have_c99_vsnprintf=true \
> +	have_c99_snprintf=true \
> +	have_unix98_printf=true
> +

This is a bit tricky because the meson configuration is typed, and we
need to avoid double quotes for the sed command.  How about changing the
description to:

    The format is `property-name=<value>` with no space around the +=+
    sign, and with single quotes around string values.

?


Regards,
John