From 2dac37c091b5cfb2eca123803fa3c8bd9701101c Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Sat, 23 Jul 2016 22:52:33 -0400
Subject: [PATCH] PR c++/70709 - zero-length array member

	* class.c (walk_subobject_offsets): Handle 0-length array.

From-SVN: r238687
---
 gcc/cp/ChangeLog                  |  3 +++
 gcc/cp/class.c                    |  3 ++-
 gcc/testsuite/g++.dg/ext/array3.C | 19 +++++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/ext/array3.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index e5275f51020..f4585a38c0d 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2016-07-23  Jason Merrill  <jason@redhat.com>
 
+	PR c++/70709
+	* class.c (walk_subobject_offsets): Handle 0-length array.
+
 	PR c++/70778
 	* pt.c (tsubst): Also substitute into the template of a
 	BOUND_TEMPLATE_TEMPLATE_PARM.
diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index b2db7f8aab8..b537b7e634c 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -4175,7 +4175,8 @@ walk_subobject_offsets (tree type,
       /* Avoid recursing into objects that are not interesting.  */
       if (!CLASS_TYPE_P (element_type)
 	  || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type)
-	  || !domain)
+	  || !domain
+	  || integer_minus_onep (TYPE_MAX_VALUE (domain)))
 	return 0;
 
       /* Step through each of the elements in the array.  */
diff --git a/gcc/testsuite/g++.dg/ext/array3.C b/gcc/testsuite/g++.dg/ext/array3.C
new file mode 100644
index 00000000000..e8940dbee21
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/array3.C
@@ -0,0 +1,19 @@
+// PR c++/70709
+// { dg-options "" }
+
+struct A
+{
+  A (int);
+};
+
+struct B
+{
+  B () {} 
+  A a[0];
+};
+
+struct C
+{
+  C () {} 
+  B a[0];
+};