Re: [dpdk-dev] [PATCH] test-meson-builds: add a 32-bit build

[Thomas Monjalon <thomas@monjalon.net>]

05/11/2020 12:21, Bruce Richardson:
> On Thu, Nov 05, 2020 at 12:13:37PM +0100, Thomas Monjalon wrote:
> > 05/11/2020 12:07, Bruce Richardson:
> > > It's reasonably common for patches to have issues when built on 32-bits, so
> > > to prevent this, we can add a 32-bit build (if supported) to the
> > > "test-meson-builds.sh" script. The tricky bit is using a valid
> > > PKG_CONFIG_LIBDIR, so for now we use two common possibilities for where that
> > > should point to in order to get a successful build.
> > > 
> > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > 
> > Thanks we really need such test.
> > 
> > > +if echo "int main(void) { return 0; }" | cc -m32 -x c - -o /dev/null 2> /dev/null ; then
> > 
> > I think a function would be cleaner, with -m32 passed as parameter.
> > 
> > > +	if [ -d "/usr/lib/i386-linux-gnu" ] ; then
> > > +		# 32-bit pkgconfig on debian/ubuntu
> > > +		export PKG_CONFIG_LIBDIR="/usr/lib/i386-linux-gnu/pkgconfig"
> > > +	else
> > > +		# 32-bit pkgconfig on RHEL/fedora (lib vs lib64)
> > > +		export PKG_CONFIG_LIBDIR="/usr/lib/pkgconfig"
> > 
> > It is /usr/lib32 on my Arch Linux.
> > 
> > I would prefer avoiding export,
> > by assigning a local variable and use it below:
> > 
> > PKG_CONFIG_LIBDIR=libdir32 build build-32-bit ...
> > 
> > > +	fi
> > > +	build build-32-bit cc -Dc_args='-m32' -Dc_link_args='-m32'
> > 
> > Or just "build-32" as directory name.
> > 
> > > +	unset PKG_CONFIG_LIBDIR
> > 
> > No need of unset if not using export above.
> > 
> > > +fi
> 
> Thanks for the quick review, I'll put together a v2 based on this feedback.

One more thing, the variable DPDK_TARGET should be set
accordingly so the right configuration can be loaded.
By default, I believe it will be x86_64-pc-linux-gnu.
We need something with "32" or i686 on x86 so we can adjust
the paths to the dependencies built for 32-bit.