Enable "missing prototypes" warning for gcc, clang

Missing prototypes for exported functions cause a really huge issue on
Windows.  Enabling the "missing prototypes" warning makes it much easier
to catch this problem.  Naturally, any warnings caused by this have been
fixed.

Signed-off-by: Erik Boasson <eb@ilities.com>

src/core/ddsc/src/dds_rhc.c

@@ -217,12 +217,14 @@ static int lwregs_delete (struct lwregs *rt, uint64_t iid, uint64_t wr_iid)
   return ddsrt_ehh_remove (rt->regs, &dummy);
 }
 
+#if 0
 void lwregs_dump (struct lwregs *rt)
 {
   struct ddsrt_ehh_iter it;
   for (struct lwreg *r = ddsrt_ehh_iter_first(rt->regs, &it); r; r = ddsrt_ehh_iter_next(&it))
     printf("iid=%"PRIu64" wr_iid=%"PRIu64"\n", r->iid, r->wr_iid);
 }
+#endif
 
 /*************************
  ******     RHC     ******

src/core/ddsc/src/dds_serdata_builtintopic.c

@@ -126,7 +126,7 @@ static void from_entity_pwr (struct ddsi_serdata_builtintopic *d, const struct p
   assert (d->xqos.present & QP_TYPE_NAME);
 }
 
-struct ddsi_serdata *ddsi_serdata_builtin_from_keyhash (const struct ddsi_sertopic *tpcmn, const nn_keyhash_t *keyhash)
+static struct ddsi_serdata *ddsi_serdata_builtin_from_keyhash (const struct ddsi_sertopic *tpcmn, const nn_keyhash_t *keyhash)
 {
   /* FIXME: not quite elegant to manage the creation of a serdata for a built-in topic via this function, but I also find it quite unelegant to let from_sample read straight from the underlying internal entity, and to_sample convert to the external format ... I could claim the internal entity is the "serialised form", but that forces wrapping it in a fragchain in one way or another, which, though possible, is also a bit lacking in elegance. */
   const struct ddsi_sertopic_builtintopic *tp = (const struct ddsi_sertopic_builtintopic *)tpcmn;

src/core/ddsc/src/dds_waitset.c

@@ -133,7 +133,7 @@ static bool dds_waitset_remove_from_list (dds_attachment **list, dds_entity_t ob
   return true;
 }
 
-dds_return_t dds_waitset_close (struct dds_entity *e)
+static dds_return_t dds_waitset_close (struct dds_entity *e)
 {
   dds_waitset *ws = (dds_waitset *) e;
   dds_waitset_close_list (&ws->observed,  e->m_hdllink.hdl);
@@ -206,7 +206,7 @@ static void dds_waitset_remove (dds_waitset *ws, dds_entity_t observed)
 }
 
 /* This is called when the observed entity signals a status change. */
-void dds_waitset_observer (dds_entity_t observer, dds_entity_t observed, uint32_t status)
+static void dds_waitset_observer (dds_entity_t observer, dds_entity_t observed, uint32_t status)
 {
   dds_waitset *ws;
   if (dds_waitset_lock (observer, &ws) == DDS_RETCODE_OK) {

src/core/ddsc/tests/entity_api.c

@@ -24,7 +24,7 @@
 static dds_entity_t entity = -1;
 
 /* Fixture to create prerequisite entity */
-void create_entity(void)
+static void create_entity(void)
 {
     CU_ASSERT_EQUAL_FATAL(entity, -1);
     entity = dds_create_participant(DDS_DOMAIN_DEFAULT, NULL, NULL);
@@ -32,7 +32,7 @@ void create_entity(void)
 }
 
 /* Fixture to delete prerequisite entity */
-void delete_entity(void)
+static void delete_entity(void)
 {
     CU_ASSERT_FATAL(entity > 0);
     dds_return_t ret = dds_delete(entity);
@@ -66,7 +66,7 @@ CU_Test(ddsc_entity, enable, .init = create_entity, .fini = delete_entity)
     CU_ASSERT_EQUAL_FATAL(status, DDS_RETCODE_OK);
 }
 
-void entity_qos_get_set(dds_entity_t e, const char* info)
+static void entity_qos_get_set(dds_entity_t e, const char* info)
 {
     dds_return_t status;
     dds_qos_t *qos = dds_create_qos();

src/core/ddsc/tests/return_loan.c

@@ -15,9 +15,9 @@
 #include <stdio.h>
 #include "CUnit/Test.h"
 
-dds_entity_t participant = 0, topic = 0, reader = 0, read_condition = 0;
+static dds_entity_t participant = 0, topic = 0, reader = 0, read_condition = 0;
 
-void create_entities(void)
+static void create_entities(void)
 {
     participant = dds_create_participant(DDS_DOMAIN_DEFAULT, NULL, NULL);
     CU_ASSERT_FATAL(participant > 0);
@@ -32,7 +32,7 @@ void create_entities(void)
     CU_ASSERT_FATAL(read_condition > 0);
 }
 
-void delete_entities(void)
+static void delete_entities(void)
 {
     dds_return_t result;
     result = dds_delete(participant);