Index: testsuite/g++.dg/ext/vla13.C
===================================================================
--- testsuite/g++.dg/ext/vla13.C	(revision 0)
+++ testsuite/g++.dg/ext/vla13.C	(working copy)
@@ -0,0 +1,8 @@
+// PR c++/54583
+// { dg-options "-Wunused-value" }
+
+void fred()
+{
+  int n=10;
+  double (*x)[n];
+}
Index: cp/tree.c
===================================================================
--- cp/tree.c	(revision 192997)
+++ cp/tree.c	(working copy)
@@ -824,6 +824,10 @@ build_cplus_array_type (tree elt_type, tree index_
 	}
     }
 
+  /* Avoid spurious warnings with VLAs (c++/54583).  */
+  if (TYPE_SIZE (t) && TREE_CODE (TYPE_SIZE (t)) == MULT_EXPR)
+    TREE_NO_WARNING (TYPE_SIZE (t)) = 1;
+
   /* Push these needs up so that initialization takes place
      more easily.  */
   TYPE_NEEDS_CONSTRUCTING (t)