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

[Marcin Smoczynski <marcinx.smoczynski@intel.com>]

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(+)

diff --git a/app/meson.build b/app/meson.build
index 2b9fdef74..eb04c4e46 100644
--- a/app/meson.build
+++ b/app/meson.build
@@ -25,6 +25,11 @@ default_cflags = machine_args
 # specify -D_GNU_SOURCE unconditionally
 default_cflags += '-D_GNU_SOURCE'
 
+# specify -D__BSD_VISIBLE for FreeBSD
+if is_freebsd
+	default_cflags += '-D__BSD_VISIBLE'
+endif
+
 foreach app:apps
 	build = true
 	name = app
diff --git a/drivers/meson.build b/drivers/meson.build
index 4c444f495..a1a2dfcca 100644
--- a/drivers/meson.build
+++ b/drivers/meson.build
@@ -24,6 +24,11 @@ endif
 # specify -D_GNU_SOURCE unconditionally
 default_cflags += '-D_GNU_SOURCE'
 
+# specify -D__BSD_VISIBLE for FreeBSD
+if is_freebsd
+	default_cflags += '-D__BSD_VISIBLE'
+endif
+
 foreach class:dpdk_driver_classes
 	drivers = []
 	std_deps = []
diff --git a/examples/meson.build b/examples/meson.build
index 1a6134f12..44dfdc97f 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -34,6 +34,11 @@ endif
 # specify -D_GNU_SOURCE unconditionally
 default_cflags += '-D_GNU_SOURCE'
 
+# specify -D__BSD_VISIBLE for FreeBSD
+if is_freebsd
+	default_cflags += '-D__BSD_VISIBLE'
+endif
+
 foreach example: examples
 	name = example
 	build = true
diff --git a/lib/meson.build b/lib/meson.build
index e067ce5ea..48592c35a 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -44,6 +44,11 @@ enabled_libs = [] # used to print summary at the end
 # -D_GNU_SOURCE unconditionally
 default_cflags += '-D_GNU_SOURCE'
 
+# specify -D__BSD_VISIBLE for FreeBSD
+if is_freebsd
+	default_cflags += '-D__BSD_VISIBLE'
+endif
+
 foreach l:libraries
 	build = true
 	name = l
diff --git a/mk/target/generic/rte.vars.mk b/mk/target/generic/rte.vars.mk
index 25a578ad7..5f00a0bfa 100644
--- a/mk/target/generic/rte.vars.mk
+++ b/mk/target/generic/rte.vars.mk
@@ -111,6 +111,11 @@ endif
 # always define _GNU_SOURCE
 CFLAGS += -D_GNU_SOURCE
 
+# define __BSD_VISIBLE when building for FreeBSD
+ifeq ($(CONFIG_RTE_EXEC_ENV_FREEBSD),y)
+CFLAGS += -D__BSD_VISIBLE
+endif
+
 export CFLAGS
 export LDFLAGS
 
-- 
2.21.0.windows.1