+/* Suggest alternatives for NAME, an IDENTIFIER_NODE for which name
+ lookup failed. Search through all available namespaces and print out
+ possible candidates. */
+
+void
+suggest_alternatives_for (location_t location, tree name)
+{
+ VEC(tree,heap) *candidates = NULL;
+ VEC(tree,heap) *namespaces_to_search = NULL;
+ int max_to_search = PARAM_VALUE (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP);
+ int n_searched = 0;
+ tree t;
+ unsigned ix;
+
+ VEC_safe_push (tree, heap, namespaces_to_search, global_namespace);
+
+ while (!VEC_empty (tree, namespaces_to_search)
+ && n_searched < max_to_search)
+ {
+ tree scope = VEC_pop (tree, namespaces_to_search);
+ struct scope_binding binding = EMPTY_SCOPE_BINDING;
+ cp_binding_level *level = NAMESPACE_LEVEL (scope);
+
+ /* Look in this namespace. */
+ qualified_lookup_using_namespace (name, scope, &binding, 0);
+
+ n_searched++;
+
+ if (binding.value)
+ VEC_safe_push (tree, heap, candidates, binding.value);
+
+ /* Add child namespaces. */
+ for (t = level->namespaces; t; t = DECL_CHAIN (t))
+ VEC_safe_push (tree, heap, namespaces_to_search, t);
+ }
+
+ /* If we stopped before we could examine all namespaces, inform the
+ user. Do this even if we don't have any candidates, since there
+ might be more candidates further down that we weren't able to
+ find. */
+ if (n_searched >= max_to_search
+ && !VEC_empty (tree, namespaces_to_search))
+ inform (location,
+ "maximum limit of %d namespaces searched for %qE",
+ max_to_search, name);
+
+ VEC_free (tree, heap, namespaces_to_search);
+
+ /* Nothing useful to report. */
+ if (VEC_empty (tree, candidates))
+ return;
+
+ inform_n (location, VEC_length (tree, candidates),
+ "suggested alternative:",
+ "suggested alternatives:");
+
+ FOR_EACH_VEC_ELT (tree, candidates, ix, t)
+ inform (location_of (t), " %qE", t);
+
+ VEC_free (tree, heap, candidates);
+}
+