#pragma once
+#ifndef __has_attribute
+#define FOLLY_HAS_ATTRIBUTE(x) 0
+#else
+#define FOLLY_HAS_ATTRIBUTE(x) __has_attribute(x)
+#endif
+
#ifndef __has_cpp_attribute
#define FOLLY_HAS_CPP_ATTRIBUTE(x) 0
#else
*/
#if FOLLY_HAS_CPP_ATTRIBUTE(maybe_unused)
#define FOLLY_MAYBE_UNUSED [[maybe_unused]]
-#elif FOLLY_HAS_CPP_ATTRIBUTE(gnu::unused)
-#define FOLLY_MAYBE_UNUSED [[gnu::unused]]
+#elif FOLLY_HAS_ATTRIBUTE(__unused__) || __GNUC__
+#define FOLLY_MAYBE_UNUSED __attribute__((__unused__))
#else
#define FOLLY_MAYBE_UNUSED
#endif
*/
#if FOLLY_HAS_EXTENSION(nullability)
#define FOLLY_NULLABLE _Nullable
+#define FOLLY_NONNULL _Nonnull
#else
#define FOLLY_NULLABLE
+#define FOLLY_NONNULL
#endif