From: Jason Merrill <jason@redhat.com>
Date: Thu, 25 Feb 2016 14:09:24 +0000 (-0500)
Subject: re PR c++/67364 ("accessing uninitialized member" error in constexpr context)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6a0cc1cd6c5f5fbc4675ac7c3e7a899a3d8d4475;p=gcc.git

re PR c++/67364 ("accessing uninitialized member" error in constexpr context)

	PR c++/67364
	* constexpr.c (cxx_eval_component_reference): Don't complain about
	unevaluated empty classes.

From-SVN: r233716
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index eb5cfe6b566..97296e4d222 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 d3b04b11e80..8d9168c3950 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 00000000000..694ed3d1277
--- /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;