[libunwind] Properly align _Unwind_Exception.

Summary: _Unwind_Exception is required to be double word aligned. Currently the struct is under aligned.

Reviewers: mclow.lists, compnerd, kledzik, emaste

Subscribers: emaste, cfe-commits

Differential Revision: https://reviews.llvm.org/D22543

llvm-svn: 276215

1 files changed, 21 insertions, 0 deletions

diff --git a/libunwind/test/alignment.pass.cpp b/libunwind/test/alignment.pass.cpp
new file mode 100644
index 00000000000..5ab55842621
--- /dev/null
+++ b/libunwind/test/alignment.pass.cpp
@@ -0,0 +1,21 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// The Itanium ABI requires that _Unwind_Exception objects are "double-word
+// aligned".
+
+#include <unwind.h>
+
+struct MaxAligned {} __attribute__((aligned));
+static_assert(alignof(_Unwind_Exception) == alignof(MaxAligned), "");
+
+int main()
+{
+}