+/* Callback for walk_tree, looking for LABEL_EXPR.
+ Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
+ Do not check the sub-tree of GOTO_EXPR. */
+
+static tree
+contains_label_1 (tree *tp,
+ int *walk_subtrees,
+ void *data ATTRIBUTE_UNUSED)
+{
+ switch (TREE_CODE (*tp))
+ {
+ case LABEL_EXPR:
+ return *tp;
+ case GOTO_EXPR:
+ *walk_subtrees = 0;
+ /* no break */
+ default:
+ return NULL_TREE;
+ }
+}
+
+/* Checks wheter the sub-tree ST contains a label LABEL_EXPR which is
+ accessible from outside the sub-tree. Returns NULL_TREE if no
+ addressable label is found. */
+
+static bool
+contains_label_p (tree st)
+{
+ return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
+}
+