[dpdk-dev] [PATCH v3 1/7] mk: build with _GNU_SOURCE defined by default

[Anatoly Burakov <anatoly.burakov@intel.com>]

We use _GNU_SOURCE all over the place, but often times we miss
defining it, resulting in broken builds on musl. Rather than
fixing every library's and driver's and application's makefile,
fix it by simply defining _GNU_SOURCE by default for all
builds.

Remove all usages of _GNU_SOURCE in source files and makefiles,
and also fixup a couple of instances of using __USE_GNU instead
of _GNU_SOURCE.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 app/meson.build                               |  7 +++++-
 app/test-pmd/Makefile                         |  2 --
 buildtools/pmdinfogen/pmdinfogen.c            |  1 -
 drivers/bus/dpaa/Makefile                     |  1 -
 drivers/bus/dpaa/meson.build                  |  1 -
 drivers/bus/fslmc/meson.build                 |  1 -
 drivers/bus/pci/linux/Makefile                |  2 --
 drivers/bus/pci/meson.build                   |  1 -
 drivers/crypto/dpaa2_sec/Makefile             |  1 -
 drivers/crypto/dpaa_sec/Makefile              |  1 -
 drivers/mempool/dpaa/Makefile                 |  1 -
 drivers/meson.build                           |  4 ++++
 drivers/net/mlx5/mlx5_ethdev.c                |  2 --
 drivers/net/mlx5/mlx5_socket.c                |  2 --
 drivers/net/softnic/conn.c                    |  1 -
 examples/cmdline/Makefile                     |  1 -
 examples/ethtool/ethtool-app/Makefile         |  2 +-
 examples/ip_pipeline/conn.c                   |  1 -
 examples/l2fwd-cat/Makefile                   |  2 --
 examples/l2fwd-cat/meson.build                |  1 -
 examples/load_balancer/Makefile               |  1 -
 examples/meson.build                          |  4 ++++
 .../performance-thread/l3fwd-thread/main.c    |  2 --
 .../performance-thread/pthread_shim/main.c    |  1 -
 .../pthread_shim/pthread_shim.c               |  1 -
 examples/qos_sched/Makefile                   |  2 --
 examples/tep_termination/Makefile             |  1 -
 examples/vhost/Makefile                       |  1 -
 examples/vhost_crypto/Makefile                |  1 -
 examples/vhost_crypto/meson.build             |  2 +-
 examples/vhost_scsi/Makefile                  |  4 ++--
 examples/vhost_scsi/meson.build               |  2 +-
 lib/librte_cmdline/Makefile                   |  1 -
 lib/librte_cmdline/cmdline.c                  | 24 -------------------
 lib/librte_eal/bsdapp/eal/Makefile            |  5 ----
 lib/librte_eal/linuxapp/eal/Makefile          | 16 -------------
 lib/librte_eal/meson.build                    |  1 -
 lib/librte_pdump/Makefile                     |  1 -
 lib/librte_sched/Makefile                     |  2 --
 lib/meson.build                               |  4 ++++
 mk/target/generic/rte.vars.mk                 |  3 +++
 test/test/Makefile                            |  2 --
 test/test/meson.build                         |  3 +++
 43 files changed, 29 insertions(+), 90 deletions(-)

diff --git a/app/meson.build b/app/meson.build
index 99e0b93ec..e68d949e9 100644
--- a/app/meson.build
+++ b/app/meson.build
@@ -11,13 +11,18 @@ apps = ['pdump',
 # for BSD only
 lib_execinfo = cc.find_library('execinfo', required: false)
 
+default_cflags = machine_args
+
+# specify -D_GNU_SOURCE unconditionally
+default_cflags += '-D_GNU_SOURCE'
+
 foreach app:apps
 	build = true
 	name = app
 	allow_experimental_apis = false
 	sources = []
 	includes = []
-	cflags = machine_args
+	cflags = default_cflags
 	objs = [] # other object files to link against, used e.g. for
 	          # instruction-set optimized versions of code
 
diff --git a/app/test-pmd/Makefile b/app/test-pmd/Makefile
index 2b4d604b8..3694a5e31 100644
--- a/app/test-pmd/Makefile
+++ b/app/test-pmd/Makefile
@@ -70,8 +70,6 @@ endif
 
 endif
 
-CFLAGS_cmdline.o := -D_GNU_SOURCE
-
 include $(RTE_SDK)/mk/rte.app.mk
 
 endif
diff --git a/buildtools/pmdinfogen/pmdinfogen.c b/buildtools/pmdinfogen/pmdinfogen.c
index 0f35ca46b..dc0b6d5ff 100644
--- a/buildtools/pmdinfogen/pmdinfogen.c
+++ b/buildtools/pmdinfogen/pmdinfogen.c
@@ -8,7 +8,6 @@
  *
  */
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <ctype.h>
 #include <string.h>
diff --git a/drivers/bus/dpaa/Makefile b/drivers/bus/dpaa/Makefile
index bffaa9d92..9c90e53f8 100644
--- a/drivers/bus/dpaa/Makefile
+++ b/drivers/bus/dpaa/Makefile
@@ -14,7 +14,6 @@ CFLAGS := -I$(SRCDIR) $(CFLAGS)
 CFLAGS += -O3 $(WERROR_FLAGS)
 CFLAGS += -Wno-pointer-arith
 CFLAGS += -Wno-cast-qual
-CFLAGS += -D _GNU_SOURCE
 CFLAGS += -I$(RTE_BUS_DPAA)/
 CFLAGS += -I$(RTE_BUS_DPAA)/include
 CFLAGS += -I$(RTE_BUS_DPAA)/base/qbman
diff --git a/drivers/bus/dpaa/meson.build b/drivers/bus/dpaa/meson.build
index d10b62c03..065a07dfd 100644
--- a/drivers/bus/dpaa/meson.build
+++ b/drivers/bus/dpaa/meson.build
@@ -26,4 +26,3 @@ if cc.has_argument('-Wno-cast-qual')
 endif
 
 includes += include_directories('include', 'base/qbman')
-cflags += ['-D_GNU_SOURCE']
diff --git a/drivers/bus/fslmc/meson.build b/drivers/bus/fslmc/meson.build
index 22a56a6fc..6b70882b2 100644
--- a/drivers/bus/fslmc/meson.build
+++ b/drivers/bus/fslmc/meson.build
@@ -24,4 +24,3 @@ sources = files('fslmc_bus.c',
 allow_experimental_apis = true
 
 includes += include_directories('mc', 'qbman/include', 'portal')
-cflags += ['-D_GNU_SOURCE']
diff --git a/drivers/bus/pci/linux/Makefile b/drivers/bus/pci/linux/Makefile
index 96ea1d540..90404468b 100644
--- a/drivers/bus/pci/linux/Makefile
+++ b/drivers/bus/pci/linux/Makefile
@@ -4,5 +4,3 @@
 SRCS += pci.c
 SRCS += pci_uio.c
 SRCS += pci_vfio.c
-
-CFLAGS += -D_GNU_SOURCE
diff --git a/drivers/bus/pci/meson.build b/drivers/bus/pci/meson.build
index 23d6a5fec..1236d477e 100644
--- a/drivers/bus/pci/meson.build
+++ b/drivers/bus/pci/meson.build
@@ -11,7 +11,6 @@ if host_machine.system() == 'linux'
 			'linux/pci_uio.c',
 			'linux/pci_vfio.c')
 	includes += include_directories('linux')
-	cflags += ['-D_GNU_SOURCE']
 else
 	sources += files('bsd/pci.c')
 	includes += include_directories('bsd')
diff --git a/drivers/crypto/dpaa2_sec/Makefile b/drivers/crypto/dpaa2_sec/Makefile
index da3d8f84f..6197452be 100644
--- a/drivers/crypto/dpaa2_sec/Makefile
+++ b/drivers/crypto/dpaa2_sec/Makefile
@@ -20,7 +20,6 @@ LIB = librte_pmd_dpaa2_sec.a
 CFLAGS += -DALLOW_EXPERIMENTAL_API
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
-CFLAGS += -D _GNU_SOURCE
 
 ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
 ifeq ($(shell test $(GCC_VERSION) -gt 70 && echo 1), 1)
diff --git a/drivers/crypto/dpaa_sec/Makefile b/drivers/crypto/dpaa_sec/Makefile
index 9be447041..afe8639e3 100644
--- a/drivers/crypto/dpaa_sec/Makefile
+++ b/drivers/crypto/dpaa_sec/Makefile
@@ -11,7 +11,6 @@ LIB = librte_pmd_dpaa_sec.a
 
 # build flags
 CFLAGS += -DALLOW_EXPERIMENTAL_API
-CFLAGS += -D _GNU_SOURCE
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
 
diff --git a/drivers/mempool/dpaa/Makefile b/drivers/mempool/dpaa/Makefile
index da8da1e90..4f22fbc76 100644
--- a/drivers/mempool/dpaa/Makefile
+++ b/drivers/mempool/dpaa/Makefile
@@ -10,7 +10,6 @@ LIB = librte_mempool_dpaa.a
 
 CFLAGS := -I$(SRCDIR) $(CFLAGS)
 CFLAGS += -O3 $(WERROR_FLAGS)
-CFLAGS += -D _GNU_SOURCE
 CFLAGS += -I$(RTE_SDK)/drivers/bus/dpaa
 CFLAGS += -I$(RTE_SDK)/drivers/bus/dpaa/include/
 CFLAGS += -I$(RTE_SDK)/drivers/mempool/dpaa
diff --git a/drivers/meson.build b/drivers/meson.build
index 47b4215a3..567f4a19c 100644
--- a/drivers/meson.build
+++ b/drivers/meson.build
@@ -16,6 +16,10 @@ default_cflags = machine_args
 if cc.has_argument('-Wno-format-truncation')
 	default_cflags += '-Wno-format-truncation'
 endif
+
+# specify -D_GNU_SOURCE unconditionally
+default_cflags += '-D_GNU_SOURCE'
+
 foreach class:driver_classes
 	drivers = []
 	std_deps = []
diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index 34c5b95ee..3ab448a21 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -3,8 +3,6 @@
  * Copyright 2015 Mellanox Technologies, Ltd
  */
 
-#define _GNU_SOURCE
-
 #include <stddef.h>
 #include <assert.h>
 #include <inttypes.h>
diff --git a/drivers/net/mlx5/mlx5_socket.c b/drivers/net/mlx5/mlx5_socket.c
index a3a522911..00106171d 100644
--- a/drivers/net/mlx5/mlx5_socket.c
+++ b/drivers/net/mlx5/mlx5_socket.c
@@ -3,8 +3,6 @@
  * Copyright 2016 Mellanox Technologies, Ltd
  */
 
-#define _GNU_SOURCE
-
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
diff --git a/drivers/net/softnic/conn.c b/drivers/net/softnic/conn.c
index 990cf40fc..8b6658088 100644
--- a/drivers/net/softnic/conn.c
+++ b/drivers/net/softnic/conn.c
@@ -8,7 +8,6 @@
 #include <unistd.h>
 #include <sys/types.h>
 
-#define __USE_GNU
 #include <sys/socket.h>
 
 #include <sys/epoll.h>
diff --git a/examples/cmdline/Makefile b/examples/cmdline/Makefile
index 7893c85b3..a617cce11 100644
--- a/examples/cmdline/Makefile
+++ b/examples/cmdline/Makefile
@@ -56,7 +56,6 @@ SRCS-y := main.c commands.c parse_obj_list.c
 
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
-CFLAGS_parse_obj_list.o := -D_GNU_SOURCE
 
 include $(RTE_SDK)/mk/rte.extapp.mk
 
diff --git a/examples/ethtool/ethtool-app/Makefile b/examples/ethtool/ethtool-app/Makefile
index 4cd9efdd5..9ecfc0b89 100644
--- a/examples/ethtool/ethtool-app/Makefile
+++ b/examples/ethtool/ethtool-app/Makefile
@@ -16,7 +16,7 @@ APP = ethtool
 # all source are stored in SRCS-y
 SRCS-y := main.c ethapp.c
 
-CFLAGS += -O3 -D_GNU_SOURCE -pthread -I$(SRCDIR)/../lib
+CFLAGS += -O3 -pthread -I$(SRCDIR)/../lib
 CFLAGS += $(WERROR_FLAGS)
 
 LDLIBS += -L$(subst ethtool-app,lib,$(RTE_OUTPUT))/lib
diff --git a/examples/ip_pipeline/conn.c b/examples/ip_pipeline/conn.c
index 6b08e9e8e..30fca80c1 100644
--- a/examples/ip_pipeline/conn.c
+++ b/examples/ip_pipeline/conn.c
@@ -8,7 +8,6 @@
 #include <unistd.h>
 #include <sys/types.h>
 
-#define __USE_GNU
 #include <sys/socket.h>
 
 #include <sys/epoll.h>
diff --git a/examples/l2fwd-cat/Makefile b/examples/l2fwd-cat/Makefile
index aec770c28..b6eeabde1 100644
--- a/examples/l2fwd-cat/Makefile
+++ b/examples/l2fwd-cat/Makefile
@@ -23,7 +23,6 @@ CFLAGS += -O3 $(shell pkg-config --cflags libdpdk)
 LDFLAGS_SHARED = $(shell pkg-config --libs libdpdk)
 LDFLAGS_STATIC = -Wl,-Bstatic $(shell pkg-config --static --libs libdpdk)
 
-CFLAGS += -D_GNU_SOURCE
 LDFLAGS += -lpqos
 
 build/$(APP)-shared: $(SRCS-y) Makefile $(PC_FILE) | build
@@ -66,7 +65,6 @@ endif
 EXTRA_CFLAGS += -O3 -g -Wfatal-errors
 
 CFLAGS += -I$(PQOS_INSTALL_PATH)/../include
-CFLAGS_cat.o := -D_GNU_SOURCE
 
 LDLIBS += -L$(PQOS_INSTALL_PATH)
 LDLIBS += -lpqos
diff --git a/examples/l2fwd-cat/meson.build b/examples/l2fwd-cat/meson.build
index 1234e7b55..4e2777a03 100644
--- a/examples/l2fwd-cat/meson.build
+++ b/examples/l2fwd-cat/meson.build
@@ -9,7 +9,6 @@
 pqos = cc.find_library('pqos', required: false)
 build = pqos.found()
 ext_deps += pqos
-cflags += '-D_GNU_SOURCE'
 cflags += '-I/usr/local/include' # assume pqos lib installed in /usr/local
 sources = files(
 	'cat.c', 'l2fwd-cat.c'
diff --git a/examples/load_balancer/Makefile b/examples/load_balancer/Makefile
index fc8df71e8..197b019d5 100644
--- a/examples/load_balancer/Makefile
+++ b/examples/load_balancer/Makefile
@@ -50,7 +50,6 @@ include $(RTE_SDK)/mk/rte.vars.mk
 
 CFLAGS += -O3 -g
 CFLAGS += $(WERROR_FLAGS)
-CFLAGS_config.o := -D_GNU_SOURCE
 
 # workaround for a gcc bug with noreturn attribute
 # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12603
diff --git a/examples/meson.build b/examples/meson.build
index 4ee7a1114..af81c762e 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -22,6 +22,10 @@ default_cflags = machine_args
 if cc.has_argument('-Wno-format-truncation')
 	default_cflags += '-Wno-format-truncation'
 endif
+
+# specify -D_GNU_SOURCE unconditionally
+default_cflags += '-D_GNU_SOURCE'
+
 foreach example: examples
 	name = example
 	build = true
diff --git a/examples/performance-thread/l3fwd-thread/main.c b/examples/performance-thread/l3fwd-thread/main.c
index 50fd1b00a..4f8747bc3 100644
--- a/examples/performance-thread/l3fwd-thread/main.c
+++ b/examples/performance-thread/l3fwd-thread/main.c
@@ -2,8 +2,6 @@
  * Copyright(c) 2010-2016 Intel Corporation
  */
 
-#define _GNU_SOURCE
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
diff --git a/examples/performance-thread/pthread_shim/main.c b/examples/performance-thread/pthread_shim/main.c
index 7d0d58116..03ff39436 100644
--- a/examples/performance-thread/pthread_shim/main.c
+++ b/examples/performance-thread/pthread_shim/main.c
@@ -2,7 +2,6 @@
  * Copyright(c) 2015 Intel Corporation
  */
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
diff --git a/examples/performance-thread/pthread_shim/pthread_shim.c b/examples/performance-thread/pthread_shim/pthread_shim.c
index 53f12437f..a02de0677 100644
--- a/examples/performance-thread/pthread_shim/pthread_shim.c
+++ b/examples/performance-thread/pthread_shim/pthread_shim.c
@@ -6,7 +6,6 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #include <errno.h>
-#define __USE_GNU
 #include <sched.h>
 #include <dlfcn.h>
 
diff --git a/examples/qos_sched/Makefile b/examples/qos_sched/Makefile
index a7ecf9788..45b0a9eb6 100644
--- a/examples/qos_sched/Makefile
+++ b/examples/qos_sched/Makefile
@@ -57,8 +57,6 @@ else
 
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
-CFLAGS_args.o := -D_GNU_SOURCE
-CFLAGS_cfg_file.o := -D_GNU_SOURCE
 
 include $(RTE_SDK)/mk/rte.extapp.mk
 
diff --git a/examples/tep_termination/Makefile b/examples/tep_termination/Makefile
index 8ec1a38ef..4c1564325 100644
--- a/examples/tep_termination/Makefile
+++ b/examples/tep_termination/Makefile
@@ -60,7 +60,6 @@ endif
 CFLAGS += -DALLOW_EXPERIMENTAL_API
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
-CFLAGS += -D_GNU_SOURCE
 
 include $(RTE_SDK)/mk/rte.extapp.mk
 endif
diff --git a/examples/vhost/Makefile b/examples/vhost/Makefile
index a2ea97a0c..c6964381b 100644
--- a/examples/vhost/Makefile
+++ b/examples/vhost/Makefile
@@ -61,7 +61,6 @@ else
 CFLAGS += -DALLOW_EXPERIMENTAL_API
 CFLAGS += -O2 -D_FILE_OFFSET_BITS=64
 CFLAGS += $(WERROR_FLAGS)
-CFLAGS += -D_GNU_SOURCE
 
 include $(RTE_SDK)/mk/rte.extapp.mk
 
diff --git a/examples/vhost_crypto/Makefile b/examples/vhost_crypto/Makefile
index 83d331012..a620abf49 100644
--- a/examples/vhost_crypto/Makefile
+++ b/examples/vhost_crypto/Makefile
@@ -25,7 +25,6 @@ SRCS-y := main.c
 CFLAGS += -DALLOW_EXPERIMENTAL_API
 CFLAGS += -O2 -D_FILE_OFFSET_BITS=64
 CFLAGS += $(WERROR_FLAGS)
-CFLAGS += -D_GNU_SOURCE
 
 include $(RTE_SDK)/mk/rte.extapp.mk
 
diff --git a/examples/vhost_crypto/meson.build b/examples/vhost_crypto/meson.build
index 0f4876f06..daf19fb87 100644
--- a/examples/vhost_crypto/meson.build
+++ b/examples/vhost_crypto/meson.build
@@ -8,7 +8,7 @@
 
 allow_experimental_apis = true
 deps += ['vhost', 'cryptodev']
-cflags += ['-D_GNU_SOURCE','-D_FILE_OFFSET_BITS=64']
+cflags += ['-D_FILE_OFFSET_BITS=64']
 sources = files(
 	'main.c'
 )
diff --git a/examples/vhost_scsi/Makefile b/examples/vhost_scsi/Makefile
index fa0cf727e..523aee0bf 100644
--- a/examples/vhost_scsi/Makefile
+++ b/examples/vhost_scsi/Makefile
@@ -18,7 +18,7 @@ shared: build/$(APP)-shared
 static: build/$(APP)-static
 	ln -sf $(APP)-static build/$(APP)
 
-CFLAGS += -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64
+CFLAGS += -D_FILE_OFFSET_BITS=64
 LDFLAGS += -pthread
 
 PC_FILE := $(shell pkg-config --path libdpdk)
@@ -57,7 +57,7 @@ please change the definition of the RTE_TARGET environment variable)
 all:
 else
 
-CFLAGS += -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64
+CFLAGS += -D_FILE_OFFSET_BITS=64
 CFLAGS += -O2
 CFLAGS += $(WERROR_FLAGS)
 
diff --git a/examples/vhost_scsi/meson.build b/examples/vhost_scsi/meson.build
index 5f92370f5..2303bcaed 100644
--- a/examples/vhost_scsi/meson.build
+++ b/examples/vhost_scsi/meson.build
@@ -10,7 +10,7 @@ if host_machine.system() != 'linux'
 	build = false
 endif
 deps += 'vhost'
-cflags += ['-D_GNU_SOURCE','-D_FILE_OFFSET_BITS=64']
+cflags += ['-D_FILE_OFFSET_BITS=64']
 sources = files(
 	'scsi.c', 'vhost_scsi.c'
 )
diff --git a/lib/librte_cmdline/Makefile b/lib/librte_cmdline/Makefile
index ddae1cfde..c64142b8d 100644
--- a/lib/librte_cmdline/Makefile
+++ b/lib/librte_cmdline/Makefile
@@ -25,7 +25,6 @@ SRCS-$(CONFIG_RTE_LIBRTE_CMDLINE) += cmdline_vt100.c
 SRCS-$(CONFIG_RTE_LIBRTE_CMDLINE) += cmdline_socket.c
 SRCS-$(CONFIG_RTE_LIBRTE_CMDLINE) += cmdline_parse_portlist.c
 
-CFLAGS += -D_GNU_SOURCE
 LDLIBS += -lrte_eal
 
 # install includes
diff --git a/lib/librte_cmdline/cmdline.c b/lib/librte_cmdline/cmdline.c
index 591b78b0f..d9042f048 100644
--- a/lib/librte_cmdline/cmdline.c
+++ b/lib/librte_cmdline/cmdline.c
@@ -126,35 +126,11 @@ cmdline_printf(const struct cmdline *cl, const char *fmt, ...)
 	if (!cl || !fmt)
 		return;
 
-#ifdef _GNU_SOURCE
 	if (cl->s_out < 0)
 		return;
 	va_start(ap, fmt);
 	vdprintf(cl->s_out, fmt, ap);
 	va_end(ap);
-#else
-	int ret;
-	char *buf;
-
-	if (cl->s_out < 0)
-		return;
-
-	buf = malloc(BUFSIZ);
-	if (buf == NULL)
-		return;
-	va_start(ap, fmt);
-	ret = vsnprintf(buf, BUFSIZ, fmt, ap);
-	va_end(ap);
-	if (ret < 0) {
-		free(buf);
-		return;
-	}
-	if (ret >= BUFSIZ)
-		ret = BUFSIZ - 1;
-	ret = write(cl->s_out, buf, ret);
-	(void)ret;
-	free(buf);
-#endif
 }
 
 int
diff --git a/lib/librte_eal/bsdapp/eal/Makefile b/lib/librte_eal/bsdapp/eal/Makefile
index d27da3d15..7c8e00a2e 100644
--- a/lib/librte_eal/bsdapp/eal/Makefile
+++ b/lib/librte_eal/bsdapp/eal/Makefile
@@ -77,11 +77,6 @@ SRCS-y += rte_cycles.c
 
 CFLAGS_eal_common_cpuflags.o := $(CPUFLAGS_LIST)
 
-CFLAGS_eal.o := -D_GNU_SOURCE
-#CFLAGS_eal_thread.o := -D_GNU_SOURCE
-CFLAGS_eal_log.o := -D_GNU_SOURCE
-CFLAGS_eal_common_log.o := -D_GNU_SOURCE
-
 # workaround for a gcc bug with noreturn attribute
 # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12603
 ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
diff --git a/lib/librte_eal/linuxapp/eal/Makefile b/lib/librte_eal/linuxapp/eal/Makefile
index fd92c75c2..bfee453bc 100644
--- a/lib/librte_eal/linuxapp/eal/Makefile
+++ b/lib/librte_eal/linuxapp/eal/Makefile
@@ -85,22 +85,6 @@ SRCS-y += rte_cycles.c
 
 CFLAGS_eal_common_cpuflags.o := $(CPUFLAGS_LIST)
 
-CFLAGS_eal.o := -D_GNU_SOURCE
-CFLAGS_eal_interrupts.o := -D_GNU_SOURCE
-CFLAGS_eal_vfio_mp_sync.o := -D_GNU_SOURCE
-CFLAGS_eal_timer.o := -D_GNU_SOURCE
-CFLAGS_eal_lcore.o := -D_GNU_SOURCE
-CFLAGS_eal_memalloc.o := -D_GNU_SOURCE
-CFLAGS_eal_thread.o := -D_GNU_SOURCE
-CFLAGS_eal_log.o := -D_GNU_SOURCE
-CFLAGS_eal_common_log.o := -D_GNU_SOURCE
-CFLAGS_eal_hugepage_info.o := -D_GNU_SOURCE
-CFLAGS_eal_common_whitelist.o := -D_GNU_SOURCE
-CFLAGS_eal_common_options.o := -D_GNU_SOURCE
-CFLAGS_eal_common_thread.o := -D_GNU_SOURCE
-CFLAGS_eal_common_lcore.o := -D_GNU_SOURCE
-CFLAGS_rte_cycles.o := -D_GNU_SOURCE
-
 # workaround for a gcc bug with noreturn attribute
 # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12603
 ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
diff --git a/lib/librte_eal/meson.build b/lib/librte_eal/meson.build
index e1fde15d1..f68c6733c 100644
--- a/lib/librte_eal/meson.build
+++ b/lib/librte_eal/meson.build
@@ -25,7 +25,6 @@ version = 8  # the version of the EAL API
 allow_experimental_apis = true
 deps += 'compat'
 deps += 'kvargs'
-cflags += '-D_GNU_SOURCE'
 sources = common_sources + env_sources
 objs = common_objs + env_objs
 headers = common_headers + env_headers
diff --git a/lib/librte_pdump/Makefile b/lib/librte_pdump/Makefile
index ee14dba7a..b241151dc 100644
--- a/lib/librte_pdump/Makefile
+++ b/lib/librte_pdump/Makefile
@@ -8,7 +8,6 @@ LIB = librte_pdump.a
 
 CFLAGS += -DALLOW_EXPERIMENTAL_API
 CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
-CFLAGS += -D_GNU_SOURCE
 LDLIBS += -lrte_eal -lrte_mempool -lrte_mbuf -lrte_ethdev
 
 EXPORT_MAP := rte_pdump_version.map
diff --git a/lib/librte_sched/Makefile b/lib/librte_sched/Makefile
index 55d9c6989..46c53ed71 100644
--- a/lib/librte_sched/Makefile
+++ b/lib/librte_sched/Makefile
@@ -11,8 +11,6 @@ LIB = librte_sched.a
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
 
-CFLAGS_rte_red.o := -D_GNU_SOURCE
-
 LDLIBS += -lm
 LDLIBS += -lrt
 LDLIBS += -lrte_eal -lrte_mempool -lrte_mbuf -lrte_net
diff --git a/lib/meson.build b/lib/meson.build
index 3acc67e6e..24351cc40 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -32,6 +32,10 @@ if cc.has_argument('-Wno-format-truncation')
 endif
 
 enabled_libs = [] # used to print summary at the end
+
+# -D_GNU_SOURCE unconditionally
+default_cflags += '-D_GNU_SOURCE'
+
 foreach l:libraries
 	build = true
 	name = l
diff --git a/mk/target/generic/rte.vars.mk b/mk/target/generic/rte.vars.mk
index 98085cd31..dd149acc9 100644
--- a/mk/target/generic/rte.vars.mk
+++ b/mk/target/generic/rte.vars.mk
@@ -108,6 +108,9 @@ CFLAGS += -include $(RTE_SDK_BIN)/include/rte_config.h
 LDFLAGS += -L$(RTE_SDK_BIN)/lib
 endif
 
+# always define _GNU_SOURCE
+CFLAGS += -D_GNU_SOURCE
+
 export CFLAGS
 export LDFLAGS
 
diff --git a/test/test/Makefile b/test/test/Makefile
index dcea4410d..0b7b56ca2 100644
--- a/test/test/Makefile
+++ b/test/test/Makefile
@@ -209,8 +209,6 @@ CFLAGS += -DALLOW_EXPERIMENTAL_API
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
 
-CFLAGS += -D_GNU_SOURCE
-
 LDLIBS += -lm
 ifeq ($(CONFIG_RTE_COMPRESSDEV_TEST),y)
 ifeq ($(CONFIG_RTE_LIBRTE_COMPRESSDEV),y)
diff --git a/test/test/meson.build b/test/test/meson.build
index bacb5b144..02ce75959 100644
--- a/test/test/meson.build
+++ b/test/test/meson.build
@@ -251,6 +251,9 @@ if cc.has_argument('-Wno-format-truncation')
     cflags += '-Wno-format-truncation'
 endif
 
+# specify -D_GNU_SOURCE unconditionally
+default_cflags += '-D_GNU_SOURCE'
+
 test_dep_objs = []
 compress_test_dep = dependency('zlib', required: false)
 if compress_test_dep.found()
-- 
2.17.1