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

[Bruce Richardson <bruce.richardson@intel.com>]

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?

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.

/Bruce