Re: [dpdk-dev] [PATCH] build: enable BSD features visibility for FreeBSD

["Smoczynski, MarcinX" <marcinx.smoczynski@intel.com>]

> -----Original Message-----
> From: Richardson, Bruce
> Sent: Tuesday, May 14, 2019 2:20 PM
> To: Smoczynski, MarcinX <marcinx.smoczynski@intel.com>
> Cc: thomas@monjalon.net; dev@dpdk.org; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; adrien.mazarguil@6wind.com
> Subject: Re: [PATCH] build: enable BSD features visibility for FreeBSD
> 
> On Tue, May 14, 2019 at 01:43:54PM +0200, Marcin Smoczynski wrote:
> > When a component uses either XOPEN_SOURCE or POSIX_C_SOURCE
> macro
> > explicitly in its build recipe, it restricts visibility of a non POSIX
> > features subset, such as IANA protocol numbers (IPPROTO_* macros).
> > Non standard features are enabled by default for DPDK both for Linux
> > thanks to _GNU_SOURCE and for FreeBSD thanks to __BSD_VISIBLE.
> However
> > using XOPEN_SOURCE or POSIX_(C_)SOURCE in a component causes
> > __BSD_VISIBLE to be defined to 0 for FreeBSD, causing different
> > feature sets visibility for Linux and FreeBSD. It restricts from using
> > IPPROTO macros in public headers, such as rte_ip.h, despite the fact
> > they are already widely used in sources.
> >
> > Add __BSD_VISIBLE macro specified unconditionally for FreeBSD targets
> > which enforces feature sets visibility unification between Linux and
> > FreeBSD.
> >
> > This patch solves the problem of build breaks for [1] on FreeBSD [2]
> > following the discussion [3].
> >
> > [1] https://mails.dpdk.org/archives/dev/2019-May/131885.html
> > [2] http://mails.dpdk.org/archives/test-report/2019-May/082263.html
> > [3] https://mails.dpdk.org/archives/dev/2019-May/132110.html
> >
> > Signed-off-by: Marcin Smoczynski <marcinx.smoczynski@intel.com>
> > ---
> >  app/meson.build               | 5 +++++
> >  drivers/meson.build           | 5 +++++
> >  examples/meson.build          | 5 +++++
> >  lib/meson.build               | 5 +++++
> >  mk/target/generic/rte.vars.mk | 5 +++++
> >  5 files changed, 25 insertions(+)
> >
> Rather than adding this in 4 places to the meson build, would it break
> anything to just add it using add_project_arguments() in
> config/meson.build?

Sounds good to me. I was following the way -D_GNU_SOURCE was added.
Should I move -D_GNU_SOURCE to config/meson.build too? It looks like
it is the same situation as it is with __BSD_VISIBLE.

> 
> Also, does this flag need to be used by external apps when compiling against
> DPDK headers? If so, we need to add this to the pkg-config file for DPDK on
> BSD.

Lack of this flag may break external applications builds for FreeBSD depending
of other feature flags they use. I'll add it then to the pc file.

Marcin