re PR c++/66320 (ICE: in cxx_eval_constant_expression, at cp/constexpr.c:3524)

	PR c++/66320
	* constexpr.c (cxx_eval_constant_expression): Treat a placeholder
	with the wrong type as non-constant.

From-SVN: r223901

gcc/cp/ChangeLog

+2015-05-31  Jason Merrill  <jason@redhat.com>
+
+	PR c++/66320
+	* constexpr.c (cxx_eval_constant_expression): Treat a placeholder
+	with the wrong type as non-constant.
+
 2015-05-27  Jason Merrill  <jason@redhat.com>
 
 	* decl.c (check_redeclaration_exception_specification): Depend on

gcc/cp/constexpr.c

@@ -3458,7 +3458,9 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
       break;
 
     case PLACEHOLDER_EXPR:
-      if (!ctx || !ctx->ctor || (lval && !ctx->object))
+      if (!ctx || !ctx->ctor || (lval && !ctx->object)
+	  || !(same_type_ignoring_top_level_qualifiers_p
+	       (TREE_TYPE (t), TREE_TYPE (ctx->ctor))))
 	{
 	  /* A placeholder without a referent.  We can get here when
 	     checking whether NSDMIs are noexcept, or in massage_init_elt;
@@ -3473,8 +3475,6 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
 	     use ctx->object unconditionally, but using ctx->ctor when we
 	     can is a minor optimization.  */
 	  tree ctor = lval ? ctx->object : ctx->ctor;
-	  gcc_assert (same_type_ignoring_top_level_qualifiers_p
-		      (TREE_TYPE (t), TREE_TYPE (ctor)));
 	  return cxx_eval_constant_expression
 	    (ctx, ctor, lval,
 	     non_constant_p, overflow_p);

gcc/testsuite/g++.dg/cpp0x/nsdmi11.C

+// PR c++/66320
+// { dg-do compile { target c++11 } }
+
+class A
+{
+  virtual int m_fn1 ();
+};
+class B
+{
+public:
+  B (int);
+};
+class D : B
+{
+  struct C
+  {
+    A a;
+    A b = a;
+  };
+  D (int *);
+  C _channels;
+};
+D::D (int *) : B (0) {}