Tag ununsed variable and make function real explicit prototype.

source/blender/compositor/COM_compositor.h

@@ -303,7 +303,7 @@ void COM_execute(RenderData* rd, bNodeTree *editingtree, int rendering);
  * @brief Return a list of highlighted bnodes pointers.
  * @return 
  */
-void COM_startReadHighlights();
+void COM_startReadHighlights(void);
 
 /**
  * @brief check if a bnode is highlighted

source/blender/editors/space_node/node_draw.c

@@ -1132,7 +1132,7 @@ void drawnodespace(const bContext *C, ARegion *ar, View2D *v2d)
 	
 	if (snode->nodetree) {
 		bNode *node;
-		void** highlights = 0;
+		/* void** highlights = 0; */ /* UNUSED */
 		
 		node_uiblocks_init(C, snode->nodetree);