--- /dev/null
+//
+// FABAttributes.h
+// Fabric
+//
+// Copyright (C) 2015 Twitter, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#pragma once
+
+#define FAB_UNAVAILABLE(x) __attribute__((unavailable(x)))
+
+#if !__has_feature(nullability)
+ #define nonnull
+ #define nullable
+ #define _Nullable
+ #define _Nonnull
+#endif
+
+#ifndef NS_ASSUME_NONNULL_BEGIN
+ #define NS_ASSUME_NONNULL_BEGIN
+#endif
+
+#ifndef NS_ASSUME_NONNULL_END
+ #define NS_ASSUME_NONNULL_END
+#endif
+
+
+/**
+ * The following macros are defined here to provide
+ * backwards compatability. If you are still using
+ * them you should migrate to the native nullability
+ * macros.
+ */
+#define fab_nullable nullable
+#define fab_nonnull nonnull
+#define FAB_NONNULL __fab_nonnull
+#define FAB_NULLABLE __fab_nullable
+#define FAB_START_NONNULL NS_ASSUME_NONNULL_BEGIN
+#define FAB_END_NONNULL NS_ASSUME_NONNULL_END