[dpdk-stable] [PATCH v5 04/17] build: define _GNU_SOURCE globally

[Thomas Monjalon]

26/02/2021 10:08, Bruce Richardson:
> On Thu, Feb 25, 2021 at 07:22:37PM +0100, Thomas Monjalon wrote:
> > There was an intent to define _GNU_SOURCE globally,
> > but it was not set in pkg-config for external applications.
> > 
> Is this something that we really want to do, to force all external apps to
> use _GNU_SOURCE when compiling? Do some of our header files rely on
> definitions only available with _GNU_SOURCE? If so, we should probably look
> to remove that dependency rather than mandating the define.

>From patch 5:
In musl libc, cpu_set_t is defined only if _GNU_SOURCE is defined.

If we avoid mandating _GNU_SOURCE,
we must #ifdef functions relying on rte_cpuset_t in the headers:
	- rte_lcore_cpuset
	- rte_thread_set_affinity
	- rte_thread_get_affinity
	- rte_telemetry_init (internal)
Or a different trick in linux/include/rte_os.h could be:
	typedef void rte_cpuset_t;
so it allows including files, but not using above functions of course.