re PR c++/46293 (constexpr vs. tuple, ice)

	PR c++/46293
	* semantics.c (build_data_member_initialization): Handle
	value-init of aggregate empty base.

From-SVN: r166297

gcc/cp/ChangeLog

 2010-11-03  Jason Merrill  <jason@redhat.com>
 
+	PR c++/46293
+	* semantics.c (build_data_member_initialization): Handle
+	value-init of aggregate empty base.
+
 	PR c++/46289
 	* call.c (can_convert_array): New fn.
 	(build_aggr_conv): Use it.

gcc/cp/semantics.c

@@ -5460,6 +5460,14 @@ build_data_member_initialization (tree t, VEC(constructor_elt,gc) **vec)
     {
       member = TREE_OPERAND (t, 0);
       init = unshare_expr (TREE_OPERAND (t, 1));
+      if (TREE_CODE (member) == INDIRECT_REF)
+	{
+	  /* Don't put out anything for value-init of an empty base.  */
+	  gcc_assert (is_empty_class (TREE_TYPE (member)));
+	  gcc_assert (TREE_CODE (init) == CONSTRUCTOR
+		      && CONSTRUCTOR_NELTS (init) == 0);
+	  return true;
+	}
     }
   else
     {

gcc/testsuite/ChangeLog

 2010-11-03  Jason Merrill  <jason@redhat.com>
 
+	PR c++/46293
+	* g++.dg/cpp0x/constexpr-base2.C: New.
+
 	PR c++/46289
 	* g++.dg/cpp0x/initlist45.C: New.
 

gcc/testsuite/g++.dg/cpp0x/constexpr-base2.C

+// PR c++/46293
+// { dg-options -std=c++0x }
+
+struct A
+{
+};
+
+struct C
+{
+  int i;
+  constexpr C(int i): i(i) {}
+};
+
+struct B: A, C
+{
+  constexpr B(): A(), C(42) { }
+};
+
+constexpr B b{};