re PR c++/17221 (C++ offsetof regression)

        PR c++/17221
        * pt.c (tsubst_expr): Move OFFSETOF_EXPR handling ...
        (tsubst_copy_and_build): ... here.

From-SVN: r86835

gcc/cp/ChangeLog

+2004-08-31  Richard Henderson  <rth@redhat.com>
+
+	PR c++/17221
+	* pt.c (tsubst_expr): Move OFFSETOF_EXPR handling ...
+	(tsubst_copy_and_build): ... here.
+
 2004-08-30  Mark Mitchell  <mark@codesourcery.com>
 
 	* cp-tree.h (initialize_artificial_var): Declare.

gcc/cp/pt.c

@@ -8085,11 +8085,6 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
       tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
       break;
 
-    case OFFSETOF_EXPR:
-      t = tsubst_copy_and_build (TREE_OPERAND (t, 0), args, complain,
-				 in_decl, false);
-      return fold_offsetof (t);
-
     default:
       gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
       
@@ -8630,6 +8625,9 @@ tsubst_copy_and_build (tree t,
 			     tsubst_copy (TREE_TYPE (t), args, complain, 
 					  in_decl));
 
+    case OFFSETOF_EXPR:
+      return fold_offsetof (RECUR (TREE_OPERAND (t, 0)));
+
     default:
       return tsubst_copy (t, args, complain, in_decl);
     }

gcc/testsuite/g++.dg/template/offsetof1.C

+// { dg-do compile }
+// PR c++/17221
+
+#include <cstddef>
+
+template <int N> struct Bar;
+template <> struct Bar<3> {};
+
+template <class T>
+struct Foo {
+   Bar<offsetof(T, a) + 3> k;
+};
+
+struct A { int a; };
+
+template struct Foo<A>;