[Bug c++/94346] [9/10 Regression] ICE due to handle_copy_attribute since r9-3982

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94346

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
      Known to fail|                            |10.0, 9.2.0
           Assignee|unassigned at gcc dot gnu.org      |msebor at gcc dot 
gnu.org

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
The change below avoids the ICE with no regressions in the attribute or warning
tests:

diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 9abf81d0248..c1294de2f49 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -2625,7 +2625,7 @@ handle_copy_attribute (tree *node, tree name, tree args,

   /* Copy type attributes from REF to DECL.  */
   for (tree at = attrs; at; at = TREE_CHAIN (at))
-    decl_attributes (node, at, flags, ref);
+    decl_attributes (node, at, flags, DECL_P (ref) ? ref : NULL_TREE);

   return NULL_TREE;
 }