1 files changed, 17 insertions, 0 deletions
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 7c34d94..ec47b06 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -1331,6 +1331,23 @@ handle_using_decl (tree using_decl, tree t)
 	add_method (t, *iter, true);
 	alter_access (t, *iter, access);
       }
+  else if (USING_DECL_UNRELATED_P (using_decl))
+    {
+      /* C++20 using enum can import non-inherited enumerators into class
+	 scope.  We implement that by making a copy of the CONST_DECL for which
+	 CONST_DECL_USING_P is true.  */
+      gcc_assert (TREE_CODE (decl) == CONST_DECL);
+
+      tree copy = copy_decl (decl);
+      DECL_CONTEXT (copy) = t;
+      DECL_ARTIFICIAL (copy) = true;
+      /* We emitted debug info for the USING_DECL above; make sure we don't
+	 also emit anything for this clone.  */
+      DECL_IGNORED_P (copy) = true;
+      DECL_SOURCE_LOCATION (copy) = DECL_SOURCE_LOCATION (using_decl);
+      finish_member_declaration (copy);
+      DECL_ABSTRACT_ORIGIN (copy) = decl;
+    }
   else
     alter_access (t, decl, access);
 }