From 7466a678b0c9717463f4e0bf01b7d22ff8143bdd Mon Sep 17 00:00:00 2001
From: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 25 Feb 2016 14:09:24 +0000
Subject: [PATCH] 	PR c++/67364 	* constexpr.c
 (cxx_eval_component_reference): Don't complain about 	unevaluated empty
 classes.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@233716 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/cp/ChangeLog                               |  4 ++++
 gcc/cp/constexpr.c                             |  3 ++-
 gcc/testsuite/g++.dg/cpp0x/constexpr-empty10.C | 17 +++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-empty10.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index eb5cfe6..97296e4 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2016-02-25  Jason Merrill  <jason@redhat.com>
 
+	PR c++/67364
+	* constexpr.c (cxx_eval_component_reference): Don't complain about
+	unevaluated empty classes.
+
 	PR c++/68049
 	* tree.c (strip_typedefs): Use DECL_ORIGINAL_TYPE.
 
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index d3b04b1..8d9168c 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -1983,7 +1983,8 @@ cxx_eval_component_reference (const constexpr_ctx *ctx, tree t,
       return t;
     }
 
-  if (CONSTRUCTOR_NO_IMPLICIT_ZERO (whole))
+  if (CONSTRUCTOR_NO_IMPLICIT_ZERO (whole)
+      && !is_empty_class (TREE_TYPE (part)))
     {
       /* 'whole' is part of the aggregate initializer we're currently
 	 building; if there's no initializer for this member yet, that's an
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-empty10.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-empty10.C
new file mode 100644
index 0000000..694ed3d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-empty10.C
@@ -0,0 +1,17 @@
+// PR c++/67364
+// { dg-do compile { target c++11 } }
+
+template <typename Xn>
+struct element : Xn {
+  constexpr element() : Xn() { }
+};
+
+template <typename Xn>
+struct closure {
+  element<Xn> member;
+  constexpr closure() { }
+};
+
+struct empty { };
+constexpr closure<empty> tup{};
+constexpr empty first = tup.member;
-- 
2.7.4