Re: [libvirt PATCH v2 1/1] meson: Check header usability

On 4/27/23 14:22, Andrea Bolognani wrote: > This fixes cross-building in some scenarios. > > Specifically, when building for armv7l on x86_64, has_header() > will see the x86_64 version of the linux/kmv.h header and > consider it to be usable. Later, when an attempt is made to > actually include it, the compiler will quickly realize that > things can't quite work. > > The reason why we haven't hit this in our CI is that we only ever > install the foreign version of header files. When building the > Debian package, however, some of the Debian-specific tooling will > bring in the native version of the Linux headers in addition to > the foreign one, causing meson to misreport the header's > availability status. > > Checking for actual usability, as opposed to mere presence, of > headers is enough to make things work correctly in all cases. > > The meson documentation recommends using has_header() instead of > check_header() whenever possible for performance reasons, but > while testing this change on fairly old and underpowered hardware > I haven't been able to measure any meaningful slowdown. > > https://bugs.debian.org/1024504 > > Suggested-by: Helmut Grohne <helmut(a)subdivi.de&gt; > Signed-off-by: Andrea Bolognani <abologna(a)redhat.com&gt; > --- > meson.build | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com&gt;