-* Notify normal and block edges.
-*/
-extern void edges_notify_edge(ir_node *src, int pos, ir_node *tgt, ir_node *old_tgt, ir_graph *irg);
+ * Notify normal and block edges.
+ */
+void edges_notify_edge(ir_node *src, int pos, ir_node *tgt, ir_node *old_tgt, ir_graph *irg);
+
+/**
+ * Walks only over Block nodes in the graph. Uses the block visited
+ * flag, so that it can be interleaved with another walker.
+ *
+ * @param block the start block
+ * @param pre the pre visit function
+ * @param post the post visit function
+ * @param env the environment for the walker
+ */
+void irg_block_edges_walk(ir_node *block, irg_walk_func *pre, irg_walk_func *post, void *env);