diff --git a/examples/nvme/perf/perf.c b/examples/nvme/perf/perf.c
index 8d6f5588f..f37b0fb5e 100644
--- a/examples/nvme/perf/perf.c
+++ b/examples/nvme/perf/perf.c
@@ -291,7 +291,7 @@ aio_check_io(struct ns_entry *entry)
 }
 #endif /* HAVE_LIBAIO */
 
-void task_ctor(struct rte_mempool *mp, void *arg, void *__task, unsigned id)
+static void task_ctor(struct rte_mempool *mp, void *arg, void *__task, unsigned id)
 {
 	struct perf_task *task = __task;
 	task->buf = rte_malloc(NULL, g_io_size_bytes, 0x200);
diff --git a/lib/memory/vtophys.c b/lib/memory/vtophys.c
index f85466270..6cec9a106 100644
--- a/lib/memory/vtophys.c
+++ b/lib/memory/vtophys.c
@@ -127,7 +127,7 @@ vtophys_get_map(uint64_t vfn_2mb)
 	return map_2mb;
 }
 
-uint64_t
+static uint64_t
 vtophys_get_pfn_2mb(uint64_t vfn_2mb)
 {
 	uintptr_t vaddr, paddr;
diff --git a/lib/util/file.c b/lib/util/file.c
index e736da5ce..07fb7157c 100644
--- a/lib/util/file.c
+++ b/lib/util/file.c
@@ -31,6 +31,8 @@
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "spdk/file.h"
+
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
diff --git a/mk/spdk.common.mk b/mk/spdk.common.mk
index 866920a9d..b5987033a 100644
--- a/mk/spdk.common.mk
+++ b/mk/spdk.common.mk
@@ -43,7 +43,7 @@ endif
 
 OS := $(shell uname)
 
-COMMON_CFLAGS = -g $(C_OPT) -Wall -Wextra -Wno-unused-parameter -Werror -fno-strict-aliasing -march=native -m64 -I$(SPDK_ROOT_DIR)/include
+COMMON_CFLAGS = -g $(C_OPT) -Wall -Wextra -Wno-unused-parameter -Wmissing-declarations -Werror -fno-strict-aliasing -march=native -m64 -I$(SPDK_ROOT_DIR)/include
 
 COMMON_CFLAGS += -Wformat -Wformat-security -Wformat-nonliteral
 
diff --git a/test/lib/nvme/unit/nvme_c/nvme_ut.c b/test/lib/nvme/unit/nvme_c/nvme_ut.c
index 65d60de93..4d9b0adfd 100644
--- a/test/lib/nvme/unit/nvme_c/nvme_ut.c
+++ b/test/lib/nvme/unit/nvme_c/nvme_ut.c
@@ -69,7 +69,7 @@ nvme_ctrlr_start(struct nvme_controller *ctrlr)
 	return 0;
 }
 
-void prepare_for_test(uint32_t max_io_queues)
+static void prepare_for_test(uint32_t max_io_queues)
 {
 	struct nvme_driver *driver = &g_nvme_driver;
 
@@ -86,7 +86,7 @@ void prepare_for_test(uint32_t max_io_queues)
 	threads_fail = 0;
 }
 
-void *
+static void *
 nvme_thread(void *arg)
 {
 	int rc;
@@ -108,7 +108,7 @@ nvme_thread(void *arg)
 	pthread_exit(NULL);
 }
 
-void
+static void
 test1(void)
 {
 	struct nvme_driver *driver = &g_nvme_driver;
@@ -136,7 +136,7 @@ test1(void)
 	CU_ASSERT(driver->ioq_index_pool_next == 0);
 }
 
-void
+static void
 test2(void)
 {
 	int num_threads = 16;
diff --git a/test/lib/nvme/unit/nvme_ctrlr_c/nvme_ctrlr_ut.c b/test/lib/nvme/unit/nvme_ctrlr_c/nvme_ctrlr_ut.c
index 11d452827..22fc2d1c3 100644
--- a/test/lib/nvme/unit/nvme_ctrlr_c/nvme_ctrlr_ut.c
+++ b/test/lib/nvme/unit/nvme_ctrlr_c/nvme_ctrlr_ut.c
@@ -163,7 +163,7 @@ nvme_allocate_request(void *payload, uint32_t payload_size,
 	return req;
 }
 
-void
+static void
 test_nvme_ctrlr_fail(void)
 {
 	struct nvme_controller	ctrlr = {};
diff --git a/test/lib/nvme/unit/nvme_ctrlr_cmd_c/nvme_ctrlr_cmd_ut.c b/test/lib/nvme/unit/nvme_ctrlr_cmd_c/nvme_ctrlr_cmd_ut.c
index 4332628a7..c0737f25d 100644
--- a/test/lib/nvme/unit/nvme_ctrlr_cmd_c/nvme_ctrlr_cmd_ut.c
+++ b/test/lib/nvme/unit/nvme_ctrlr_cmd_c/nvme_ctrlr_cmd_ut.c
@@ -55,7 +55,7 @@ uint16_t abort_sqid = 1;
 typedef void (*verify_request_fn_t)(struct nvme_request *req);
 verify_request_fn_t verify_fn;
 
-void verify_firmware_log_page(struct nvme_request *req)
+static void verify_firmware_log_page(struct nvme_request *req)
 {
 	uint32_t temp_cdw10;
 
@@ -67,7 +67,7 @@ void verify_firmware_log_page(struct nvme_request *req)
 	CU_ASSERT(req->cmd.cdw10 == temp_cdw10);
 }
 
-void verify_health_log_page(struct nvme_request *req)
+static void verify_health_log_page(struct nvme_request *req)
 {
 	uint32_t temp_cdw10;
 
@@ -79,7 +79,7 @@ void verify_health_log_page(struct nvme_request *req)
 	CU_ASSERT(req->cmd.cdw10 == temp_cdw10);
 }
 
-void verify_error_log_page(struct nvme_request *req)
+static void verify_error_log_page(struct nvme_request *req)
 {
 	uint32_t temp_cdw10;
 
@@ -91,27 +91,27 @@ void verify_error_log_page(struct nvme_request *req)
 	CU_ASSERT(req->cmd.cdw10 == temp_cdw10);
 }
 
-void verify_set_feature_cmd(struct nvme_request *req)
+static void verify_set_feature_cmd(struct nvme_request *req)
 {
 	CU_ASSERT(req->cmd.opc == NVME_OPC_SET_FEATURES);
 	CU_ASSERT(req->cmd.cdw10 == feature);
 	CU_ASSERT(req->cmd.cdw11 == feature_cdw11);
 }
 
-void verify_get_feature_cmd(struct nvme_request *req)
+static void verify_get_feature_cmd(struct nvme_request *req)
 {
 	CU_ASSERT(req->cmd.opc == NVME_OPC_GET_FEATURES);
 	CU_ASSERT(req->cmd.cdw10 == get_feature);
 	CU_ASSERT(req->cmd.cdw11 == get_feature_cdw11);
 }
 
-void verify_abort_cmd(struct nvme_request *req)
+static void verify_abort_cmd(struct nvme_request *req)
 {
 	CU_ASSERT(req->cmd.opc == NVME_OPC_ABORT);
 	CU_ASSERT(req->cmd.cdw10 == (((uint32_t)abort_cid << 16) | abort_sqid));
 }
 
-void verify_io_raw_cmd(struct nvme_request *req)
+static void verify_io_raw_cmd(struct nvme_request *req)
 {
 	struct nvme_command	command = {};
 
@@ -159,7 +159,7 @@ nvme_ctrlr_submit_admin_request(struct nvme_controller *ctrlr, struct nvme_reque
 }
 
 
-void
+static void
 test_firmware_get_log_page()
 {
 	struct nvme_controller			ctrlr = {};
@@ -170,7 +170,7 @@ test_firmware_get_log_page()
 	nvme_ctrlr_cmd_get_firmware_page(&ctrlr, &payload, NULL, NULL);
 }
 
-void
+static void
 test_health_get_log_page()
 {
 	struct nvme_controller			ctrlr = {};
@@ -181,7 +181,7 @@ test_health_get_log_page()
 	nvme_ctrlr_cmd_get_health_information_page(&ctrlr, health_log_nsid, &payload, NULL, NULL);
 }
 
-void
+static void
 test_error_get_log_page()
 {
 	struct nvme_controller			ctrlr = {};
@@ -196,7 +196,7 @@ test_error_get_log_page()
 	nvme_ctrlr_cmd_get_error_page(&ctrlr, &payload, error_num_entries, NULL, NULL);
 }
 
-void
+static void
 test_set_feature_cmd()
 {
 	struct nvme_controller  ctrlr = {};
@@ -207,7 +207,7 @@ test_set_feature_cmd()
 }
 
 
-void
+static void
 test_get_feature_cmd()
 {
 	struct nvme_controller	ctrlr = {};
@@ -217,7 +217,7 @@ test_get_feature_cmd()
 	nvme_ctrlr_cmd_get_feature(&ctrlr, get_feature, get_feature_cdw11, NULL, 0, NULL, NULL);
 }
 
-void
+static void
 test_abort_cmd()
 {
 	struct nvme_controller	ctrlr = {};
@@ -227,7 +227,7 @@ test_abort_cmd()
 	nvme_ctrlr_cmd_abort(&ctrlr, abort_cid, abort_sqid, NULL, NULL);
 }
 
-void
+static void
 test_io_raw_cmd()
 {
 	struct nvme_controller	ctrlr = {};
diff --git a/test/lib/nvme/unit/nvme_ns_cmd_c/nvme_ns_cmd_ut.c b/test/lib/nvme/unit/nvme_ns_cmd_c/nvme_ns_cmd_ut.c
index a0ac9632f..872f16e29 100644
--- a/test/lib/nvme/unit/nvme_ns_cmd_c/nvme_ns_cmd_ut.c
+++ b/test/lib/nvme/unit/nvme_ns_cmd_c/nvme_ns_cmd_ut.c
@@ -86,7 +86,7 @@ nvme_ctrlr_submit_io_request(struct nvme_controller *ctrlr,
 	g_request = req;
 }
 
-void
+static void
 prepare_for_test(struct nvme_namespace *ns, struct nvme_controller *ctrlr,
 		 uint32_t sector_size, uint32_t max_xfer_size,
 		 uint32_t stripe_size)
@@ -102,7 +102,7 @@ prepare_for_test(struct nvme_namespace *ns, struct nvme_controller *ctrlr,
 	g_request = NULL;
 }
 
-void
+static void
 nvme_cmd_interpret_rw(const struct nvme_command *cmd,
 		      uint64_t *lba, uint32_t *num_blocks)
 {
@@ -110,7 +110,7 @@ nvme_cmd_interpret_rw(const struct nvme_command *cmd,
 	*num_blocks = (cmd->cdw12 & 0xFFFFu) + 1;
 }
 
-void
+static void
 split_test(void)
 {
 	struct nvme_namespace	ns;
@@ -139,7 +139,7 @@ split_test(void)
 	nvme_free_request(g_request);
 }
 
-void
+static void
 split_test2(void)
 {
 	struct nvme_namespace	ns;
@@ -192,7 +192,7 @@ split_test2(void)
 	nvme_free_request(g_request);
 }
 
-void
+static void
 split_test3(void)
 {
 	struct nvme_namespace	ns;
@@ -247,7 +247,7 @@ split_test3(void)
 	nvme_free_request(g_request);
 }
 
-void
+static void
 split_test4(void)
 {
 	struct nvme_namespace	ns;
@@ -313,7 +313,7 @@ split_test4(void)
 	nvme_free_request(g_request);
 }
 
-void
+static void
 test_nvme_ns_cmd_flush(void)
 {
 	struct nvme_namespace	ns;
@@ -330,7 +330,7 @@ test_nvme_ns_cmd_flush(void)
 	nvme_free_request(g_request);
 }
 
-void
+static void
 test_nvme_ns_cmd_deallocate(void)
 {
 	struct nvme_namespace	ns;
diff --git a/test/lib/nvme/unit/nvme_qpair_c/nvme_qpair_ut.c b/test/lib/nvme/unit/nvme_qpair_c/nvme_qpair_ut.c
index 1d314e4cc..bd67cba37 100644
--- a/test/lib/nvme/unit/nvme_qpair_c/nvme_qpair_ut.c
+++ b/test/lib/nvme/unit/nvme_qpair_c/nvme_qpair_ut.c
@@ -55,14 +55,6 @@ uint64_t nvme_vtophys(void *buf)
 	}
 }
 
-void nvme_dump_completion(struct nvme_completion *cpl)
-{
-}
-
-void prepare_for_test(void)
-{
-}
-
 struct nvme_request *
 nvme_allocate_request(void *payload, uint32_t payload_size,
 		      nvme_cb_fn_t cb_fn, void *cb_arg)
@@ -107,7 +99,7 @@ nvme_free_request(struct nvme_request *req)
 	nvme_dealloc_request(req);
 }
 
-void
+static void
 test1(void)
 {
 	struct nvme_qpair qpair = {};
@@ -128,7 +120,7 @@ test1(void)
 	CU_ASSERT(strstr(outbuf, "IDENTIFY") != NULL);
 }
 
-void
+static void
 test2(void)
 {
 	struct nvme_qpair qpair = {};
@@ -149,7 +141,7 @@ test2(void)
 	CU_ASSERT(strstr(outbuf, "DATASET MANAGEMENT") != NULL);
 }
 
-void
+static void
 prepare_submit_request_test(struct nvme_qpair *qpair,
 			    struct nvme_controller *ctrlr,
 			    struct nvme_registers *regs)
@@ -164,25 +156,25 @@ prepare_submit_request_test(struct nvme_qpair *qpair,
 	fail_vtophys = false;
 }
 
-void
+static void
 cleanup_submit_request_test(struct nvme_qpair *qpair)
 {
 	nvme_qpair_destroy(qpair);
 }
 
-void
+static void
 expected_success_callback(void *arg, const struct nvme_completion *cpl)
 {
 	CU_ASSERT(!nvme_completion_is_error(cpl));
 }
 
-void
+static void
 expected_failure_callback(void *arg, const struct nvme_completion *cpl)
 {
 	CU_ASSERT(nvme_completion_is_error(cpl));
 }
 
-void
+static void
 test3(void)
 {
 	struct nvme_qpair	qpair = {};
@@ -205,7 +197,7 @@ test3(void)
 	nvme_free_request(req);
 }
 
-void
+static void
 test4(void)
 {
 	struct nvme_qpair	qpair = {};
@@ -238,7 +230,7 @@ test4(void)
 	cleanup_submit_request_test(&qpair);
 }
 
-void
+static void
 test_ctrlr_failed(void)
 {
 	struct nvme_qpair	qpair = {};
@@ -272,7 +264,7 @@ test_ctrlr_failed(void)
 	cleanup_submit_request_test(&qpair);
 }
 
-void struct_packing(void)
+static void struct_packing(void)
 {
 	/* ctrlr is the first field in nvme_qpair after the fields
 	 * that are used in the I/O path. Make sure the I/O path fields
@@ -281,7 +273,7 @@ void struct_packing(void)
 	CU_ASSERT(offsetof(struct nvme_qpair, ctrlr) <= 128);
 }
 
-void test_nvme_qpair_fail(void)
+static void test_nvme_qpair_fail(void)
 {
 	struct nvme_qpair	qpair = {};
 	struct nvme_request	*req = NULL;
@@ -311,7 +303,7 @@ void test_nvme_qpair_fail(void)
 	cleanup_submit_request_test(&qpair);
 }
 
-void test_nvme_qpair_process_completions(void)
+static void test_nvme_qpair_process_completions(void)
 {
 	struct nvme_qpair	qpair = {};
 	struct nvme_controller	ctrlr = {};
@@ -325,7 +317,7 @@ void test_nvme_qpair_process_completions(void)
 	cleanup_submit_request_test(&qpair);
 }
 
-void test_nvme_qpair_destroy(void)
+static void test_nvme_qpair_destroy(void)
 {
 	struct nvme_qpair	qpair = {};
 	struct nvme_controller	ctrlr = {};
@@ -346,7 +338,7 @@ void test_nvme_qpair_destroy(void)
 	nvme_qpair_destroy(&qpair);
 }
 
-void test_nvme_completion_is_retry(void)
+static void test_nvme_completion_is_retry(void)
 {
 	struct nvme_completion	cpl = {};
 
@@ -407,7 +399,7 @@ void test_nvme_completion_is_retry(void)
 	CU_ASSERT_FALSE(nvme_completion_is_retry(&cpl));
 }
 
-void
+static void
 test_get_status_string(void)
 {
 	const char	*status_string;