fix clang 10 warnings

the typesystem checks in g_atomic_pointer_compare_and_exchange
seem to trigger some false positives with clang 10

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/584>

gst/gstcaps.c

@@ -929,7 +929,8 @@ gst_caps_get_features (const GstCaps * caps, guint index)
     gst_caps_features_set_parent_refcount (features, &GST_CAPS_REFCOUNT (caps));
 
     storage = gst_caps_get_features_storage_unchecked (caps, index);
-    if (!g_atomic_pointer_compare_and_exchange (storage, NULL, features)) {
+    if (!g_atomic_pointer_compare_and_exchange (storage,
+            (GstCapsFeatures *) NULL, features)) {
       /* Someone did the same we just tried in the meantime */
       gst_caps_features_set_parent_refcount (features, NULL);
       gst_caps_features_free (features);

gst/gstdeviceproviderfactory.c

@@ -292,7 +292,8 @@ gst_device_provider_factory_get (GstDeviceProviderFactory * factory)
    * an device provider at the same moment
    */
   oclass = GST_DEVICE_PROVIDER_GET_CLASS (device_provider);
-  if (!g_atomic_pointer_compare_and_exchange (&oclass->factory, NULL, factory)) {
+  if (!g_atomic_pointer_compare_and_exchange (&oclass->factory,
+          (GstDeviceProviderFactory *) NULL, factory)) {
     gst_object_unref (factory);
   } else {
     /* This ref will never be dropped as the class is never destroyed */
@@ -302,8 +303,8 @@ gst_device_provider_factory_get (GstDeviceProviderFactory * factory)
   gst_object_ref_sink (device_provider);
 
   /* We use an atomic to make sure we don't create two in parallel */
-  if (!g_atomic_pointer_compare_and_exchange (&newfactory->provider, NULL,
+  if (!g_atomic_pointer_compare_and_exchange (&newfactory->provider,
-          device_provider)) {
+          (GstDeviceProvider *) NULL, device_provider)) {
     gst_object_unref (device_provider);
 
     device_provider = g_atomic_pointer_get (&newfactory->provider);

gst/gstelementfactory.c

@@ -381,8 +381,8 @@ gst_element_factory_create (GstElementFactory * factory, const gchar * name)
    * an element at the same moment
    */
   oclass = GST_ELEMENT_GET_CLASS (element);
-  if (!g_atomic_pointer_compare_and_exchange (&oclass->elementfactory, NULL,
+  if (!g_atomic_pointer_compare_and_exchange (&oclass->elementfactory,
-          factory))
+          (GstElementFactory *) NULL, factory))
     gst_object_unref (factory);
   else
     /* This ref will never be dropped as the class is never destroyed */

gst/gstminiobject.c

@@ -722,7 +722,7 @@ gst_mini_object_replace (GstMiniObject ** olddata, GstMiniObject * newdata)
       *olddata, *olddata ? (*olddata)->refcount : 0,
       newdata, newdata ? newdata->refcount : 0);
 
-  olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
+  olddata_val = (GstMiniObject *) g_atomic_pointer_get ((gpointer *) olddata);
 
   if (G_UNLIKELY (olddata_val == newdata))
     return FALSE;
@@ -731,7 +731,7 @@ gst_mini_object_replace (GstMiniObject ** olddata, GstMiniObject * newdata)
     gst_mini_object_ref (newdata);
 
   while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
-              olddata, olddata_val, newdata))) {
+              olddata, (gpointer) olddata_val, newdata))) {
     olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
     if (G_UNLIKELY (olddata_val == newdata))
       break;
@@ -764,11 +764,11 @@ gst_mini_object_steal (GstMiniObject ** olddata)
       *olddata, *olddata ? (*olddata)->refcount : 0);
 
   do {
-    olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
+    olddata_val = (GstMiniObject *) g_atomic_pointer_get ((gpointer *) olddata);
     if (olddata_val == NULL)
       break;
   } while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
-              olddata, olddata_val, NULL)));
+              olddata, (gpointer) olddata_val, NULL)));
 
   return olddata_val;
 }
@@ -800,11 +800,11 @@ gst_mini_object_take (GstMiniObject ** olddata, GstMiniObject * newdata)
       newdata, newdata ? newdata->refcount : 0);
 
   do {
-    olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
+    olddata_val = (GstMiniObject *) g_atomic_pointer_get ((gpointer *) olddata);
     if (G_UNLIKELY (olddata_val == newdata))
       break;
   } while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
-              olddata, olddata_val, newdata)));
+              olddata, (gpointer) olddata_val, newdata)));
 
   if (olddata_val)
     gst_mini_object_unref (olddata_val);

gst/gstobject.c

@@ -349,7 +349,7 @@ gst_object_replace (GstObject ** oldobj, GstObject * newobj)
       newobj ? G_OBJECT (newobj)->ref_count : 0);
 #endif
 
-  oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
+  oldptr = (GstObject *) g_atomic_pointer_get ((gpointer *) oldobj);
 
   if (G_UNLIKELY (oldptr == newobj))
     return FALSE;
@@ -358,7 +358,7 @@ gst_object_replace (GstObject ** oldobj, GstObject * newobj)
     gst_object_ref (newobj);
 
   while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
-              oldobj, oldptr, newobj))) {
+              oldobj, (gpointer) oldptr, newobj))) {
     oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
     if (G_UNLIKELY (oldptr == newobj))
       break;

gst/gststructure.c

@@ -603,7 +603,7 @@ gst_structure_take (GstStructure ** oldstr_ptr, GstStructure * newstr)
       return FALSE;
     }
   } while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
-              oldstr_ptr, oldstr, newstr)));
+              oldstr_ptr, (gpointer) oldstr, newstr)));
 
   if (oldstr)
     gst_structure_free (oldstr);