re PR c++/86915 (Segmentation fault for an array of auto in template parameter)

	PR c++/86915
	* decl.c (create_array_type_for_decl): Handle null name.

	* g++.dg/diagnostic/auto1.C: New test.

From-SVN: r263507

gcc/cp/ChangeLog

+2018-08-13  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/86915
+	* decl.c (create_array_type_for_decl): Handle null name.
+
 2018-08-10  Jason Merrill  <jason@redhat.com>
 
 	PR c++/86728 - C variadic generic lambda.

gcc/cp/decl.c

@@ -9838,7 +9838,10 @@ create_array_type_for_decl (tree name, tree type, tree size)
      type-specifier, the program is ill-formed.  */
   if (type_uses_auto (type))
     {
-      error ("%qD declared as array of %qT", name, type);
+      if (name)
+   error ("%qD declared as array of %qT", name, type);
+      else
+   error ("creating array of %qT", type);
       return error_mark_node;
     }
 

gcc/testsuite/ChangeLog

+2018-08-13  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/86915
+	* g++.dg/diagnostic/auto1.C: New test.
+
 2018-08-12  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/66679

gcc/testsuite/g++.dg/diagnostic/auto1.C

+// PR c++/86915
+// { dg-do compile { target c++17 } }
+
+template<auto [1]> struct S; // { dg-error "creating array of .auto." }