diff --git a/src/core/ddsc/src/dds_qos.c b/src/core/ddsc/src/dds_qos.c
index 1cebe53..d13eeeb 100644
--- a/src/core/ddsc/src/dds_qos.c
+++ b/src/core/ddsc/src/dds_qos.c
@@ -403,6 +403,7 @@ void dds_qset_prop (dds_qos_t * __restrict qos, const char * name, const char *
   dds_qprop_init (qos);
   if (dds_qprop_get_index (qos, name, &i))
   {
+    assert (&qos->property.value.props[i] != NULL); /* for Clang static analyzer */
     dds_free (qos->property.value.props[i].value);
     qos->property.value.props[i].value = dds_string_dup (value);
   }
@@ -426,6 +427,7 @@ void dds_qset_bprop (dds_qos_t * __restrict qos, const char * name, const void *
   dds_qprop_init (qos);
   if (dds_qbprop_get_index (qos, name, &i))
   {
+    assert (&qos->property.binary_value.props[i].value != NULL); /* for Clang static analyzer */
     dds_qos_data_copy_in (&qos->property.binary_value.props[i].value, value, sz, true);
   }
   else
diff --git a/src/core/ddsc/tests/qos.c b/src/core/ddsc/tests/qos.c
index 3e6e644..24be7d3 100644
--- a/src/core/ddsc/tests/qos.c
+++ b/src/core/ddsc/tests/qos.c
@@ -11,6 +11,7 @@
  */
 #include "CUnit/Test.h"
 #include "dds/dds.h"
+#include <assert.h>
 
 /****************************************************************************
  * Convenience global policies
@@ -746,6 +747,7 @@ CU_Test(ddsc_qos, bproperty, .init=qos_init, .fini=qos_fini)
     CU_ASSERT_FATAL(dds_qget_bprop (g_qos, c_bproperty_names[0], &bvalue, &size));
     CU_ASSERT_FATAL (bvalue != NULL);
     CU_ASSERT_EQUAL_FATAL (size, 3);
+    assert (c_bproperty_values[0] != NULL); /* for Clang static analyzer */
     CU_ASSERT_EQUAL_FATAL (memcmp (bvalue, c_bproperty_values[0], size), 0);
     dds_free (bvalue);
 
@@ -754,6 +756,7 @@ CU_Test(ddsc_qos, bproperty, .init=qos_init, .fini=qos_fini)
     CU_ASSERT_FATAL (dds_qget_bprop (g_qos, c_bproperty_names[0], &bvalue, &size));
     CU_ASSERT_FATAL (bvalue != NULL);
     CU_ASSERT_EQUAL_FATAL (size, 3);
+    assert (c_bproperty_values[1] != NULL); /* for Clang static analyzer */
     CU_ASSERT_EQUAL_FATAL (memcmp (bvalue, c_bproperty_values[1], size), 0);
     dds_free (bvalue);
     dds_qset_bprop (g_qos, c_bproperty_names[0], &c_bproperty_values[0], 3);
@@ -782,11 +785,13 @@ CU_Test(ddsc_qos, bproperty, .init=qos_init, .fini=qos_fini)
     CU_ASSERT_FATAL (dds_qget_bprop (g_qos, c_bproperty_names[0], &bvalue, &size));
     CU_ASSERT_FATAL (bvalue != NULL);
     CU_ASSERT_EQUAL_FATAL (size, 3);
+    assert (c_bproperty_values[0] != NULL); /* for Clang static analyzer */
     CU_ASSERT_EQUAL_FATAL (memcmp (bvalue, c_bproperty_values[0], size), 0);
     dds_free (bvalue);
     CU_ASSERT_FATAL (dds_qget_bprop (g_qos, c_bproperty_names[2], &bvalue, &size));
     CU_ASSERT_FATAL (bvalue != NULL);
     CU_ASSERT_EQUAL_FATAL (size, 3);
+    assert (c_bproperty_values[2] != NULL); /* for Clang static analyzer */
     CU_ASSERT_EQUAL_FATAL (memcmp (bvalue, c_bproperty_values[2], size), 0);
     dds_free (bvalue);
     dds_qunset_bprop (g_qos, c_bproperty_names[0]);
@@ -809,6 +814,7 @@ CU_Test(ddsc_qos, property_mixed, .init=qos_init, .fini=qos_fini)
     CU_ASSERT_FATAL (dds_qget_bprop (g_qos, c_property_names[0], &bvalue, &size));
     CU_ASSERT_FATAL (bvalue != NULL);
     CU_ASSERT_EQUAL_FATAL (size, 3);
+    assert (c_bproperty_values[0] != NULL); /* for Clang static analyzer */
     CU_ASSERT_EQUAL_FATAL (memcmp (bvalue, c_bproperty_values[0], size), 0);
     dds_free (bvalue);
     CU_ASSERT_FATAL (dds_qget_prop (g_qos, c_property_names[0], &value));
diff --git a/src/core/ddsi/src/q_xevent.c b/src/core/ddsi/src/q_xevent.c
index 4ff5608..3c852d5 100644
--- a/src/core/ddsi/src/q_xevent.c
+++ b/src/core/ddsi/src/q_xevent.c
@@ -584,7 +584,6 @@ static void send_heartbeat_to_all_readers(struct nn_xpack *xp, struct xevent *ev
 {
   struct whc_state whcst;
   nn_mtime_t t_next;
-  int hbansreq = 0;
   unsigned count = 0;
 
   ddsrt_mutex_lock (&wr->e.lock);
@@ -592,21 +591,14 @@ static void send_heartbeat_to_all_readers(struct nn_xpack *xp, struct xevent *ev
   whc_get_state(wr->whc, &whcst);
 
   if (!writer_must_have_hb_scheduled (wr, &whcst))
-  {
-    hbansreq = 1; /* just for trace */
     t_next.v = T_NEVER;
-  }
   else if (!writer_hbcontrol_must_send (wr, &whcst, tnow))
-  {
-    hbansreq = 1; /* just for trace */
     t_next.v = tnow.v + writer_hbcontrol_intv (wr, &whcst, tnow);
-  }
   else
   {
     struct wr_prd_match *m;
     struct ddsi_guid last_guid = { .prefix = {.u = {0,0,0}}, .entityid = {0} };
-
-    hbansreq = writer_hbcontrol_ack_required (wr, &whcst, tnow);
+    const int hbansreq = writer_hbcontrol_ack_required (wr, &whcst, tnow);
     t_next.v = tnow.v + writer_hbcontrol_intv (wr, &whcst, tnow);
 
     while ((m = ddsrt_avl_lookup_succ (&wr_readers_treedef, &wr->readers, &last_guid)) != NULL)
diff --git a/src/core/ddsi/tests/security_msg.c b/src/core/ddsi/tests/security_msg.c
index 87bd734..c052a89 100644
--- a/src/core/ddsi/tests/security_msg.c
+++ b/src/core/ddsi/tests/security_msg.c
@@ -15,6 +15,7 @@
 #include "dds/ddsrt/string.h"
 #include "dds/ddsi/ddsi_security_msg.h"
 #include "mem_ser.h"
+#include <assert.h>
 
 static nn_participant_generic_message_t test_msg_in =
 {
@@ -302,6 +303,7 @@ CU_Test (ddsi_security_msg, serializer)
 
   /* Check serialization result. */
   size_t cmpsize = (len < sizeof(test_msg_ser)) ? len : sizeof(test_msg_ser);
+  assert(data != NULL); /* for Clang static analyzer */
   if (memcmp (data, test_msg_ser, cmpsize) != 0)
   {
     printf ("memcmp(%d)\n", (int)cmpsize);
diff --git a/src/ddsrt/tests/dynlib.c b/src/ddsrt/tests/dynlib.c
index 76d5871..9b8d5df 100644
--- a/src/ddsrt/tests/dynlib.c
+++ b/src/ddsrt/tests/dynlib.c
@@ -87,7 +87,7 @@ CU_Test(ddsrt_library, dlopen_unknown)
   ddsrt_dynlib_t l;
 
   r = ddsrt_dlopen("UnknownLib", false, &l);
-
+  CU_ASSERT_NOT_EQUAL(r, DDS_RETCODE_OK);
   CU_ASSERT_PTR_NULL_FATAL(l);
 
   r = ddsrt_dlerror(buffer, sizeof(buffer));
@@ -123,6 +123,7 @@ CU_Test(ddsrt_library, dlsym_unknown)
   void* f;
 
   r = ddsrt_dlopen(TEST_LIB_NAME, true, &l);
+  CU_ASSERT_EQUAL(r, DDS_RETCODE_OK);
   CU_ASSERT_PTR_NOT_NULL(l);
   TEST_ABORT_IF_NULL(l,"ddsrt_dlopen() failed. Is the proper library path set?");
 
@@ -150,17 +151,21 @@ CU_Test(ddsrt_library, call)
   ddsrt_dynlib_t l;
 
   r = ddsrt_dlopen(TEST_LIB_NAME, true, &l);
+  CU_ASSERT_EQUAL(r, DDS_RETCODE_OK);
   CU_ASSERT_PTR_NOT_NULL(l);
   TEST_ABORT_IF_NULL(l, "ddsrt_dlopen() failed. Is the proper library path set?");
 
   r = ddsrt_dlsym(l, "get_int", (void **)&f_get);
+  CU_ASSERT_EQUAL(r, DDS_RETCODE_OK);
   CU_ASSERT_PTR_NOT_NULL(f_get);
   TEST_ABORT_IF_NULL(f_get, "ddsrt_dlsym(l, \"get_int\") failed.");
 
   r = ddsrt_dlsym(l, "set_int", (void **)&f_set);
+  CU_ASSERT_EQUAL(r, DDS_RETCODE_OK);
   CU_ASSERT_PTR_NOT_NULL(f_set);
   TEST_ABORT_IF_NULL(f_set, "ddsrt_dlsym(l, \"set_int\") failed.");
 
+  assert(f_set != 0 && f_get != 0); /* for Clang static analyzer */
   f_set(set_int);
   get_int = f_get();
   CU_ASSERT_EQUAL(set_int, get_int);
@@ -175,6 +180,7 @@ CU_Test(ddsrt_library, dlclose_error)
     ddsrt_dynlib_t l;
 
     r = ddsrt_dlopen(TEST_LIB_NAME, true, &l);
+    CU_ASSERT_EQUAL(r, DDS_RETCODE_OK);
     CU_ASSERT_PTR_NOT_NULL(l);
     TEST_ABORT_IF_NULL(l, "ddsrt_dlopen() failed. Is the proper library path set?");
 
diff --git a/src/ddsrt/tests/string.c b/src/ddsrt/tests/string.c
index babe9af..2d809ea 100644
--- a/src/ddsrt/tests/string.c
+++ b/src/ddsrt/tests/string.c
@@ -10,6 +10,7 @@
  * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
  */
 #include <string.h>
+#include <assert.h>
 
 #include "CUnit/Theory.h"
 #include "dds/ddsrt/heap.h"
@@ -82,6 +83,7 @@ CU_Theory((const char *str, const char *srch, const char *subst, size_t max, con
   if (exp != NULL)
   {
     CU_ASSERT_FATAL(r != NULL);
+    assert(r != NULL); /* for Clang static analyzer */
     CU_ASSERT(strcmp(r, exp) == 0);
     ddsrt_free(r);
   }