+/* Similarly to ARG_UNUSED below. Prior to GCC 3.4, the C++ frontend
+ couldn't parse attributes placed after the identifier name, and now
+ the entire compiler is built with C++. */
+#ifndef ATTRIBUTE_UNUSED
+#if GCC_VERSION >= 3004
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#else
+#define ATTRIBUTE_UNUSED
+#endif
+#endif /* ATTRIBUTE_UNUSED */
+
+/* Before GCC 3.4, the C++ frontend couldn't parse attributes placed after the
+ identifier name. */
+#if ! defined(__cplusplus) || (GCC_VERSION >= 3004)
+# define ARG_UNUSED(NAME) NAME ATTRIBUTE_UNUSED
+#else /* !__cplusplus || GNUC >= 3.4 */
+# define ARG_UNUSED(NAME) NAME
+#endif /* !__cplusplus || GNUC >= 3.4 */
+
+#ifndef ATTRIBUTE_NORETURN
+#define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
+#endif /* ATTRIBUTE_NORETURN */
+
+/* Attribute `nonnull' was valid as of gcc 3.3. */
+#ifndef ATTRIBUTE_NONNULL
+# if (GCC_VERSION >= 3003)
+# define ATTRIBUTE_NONNULL(m) __attribute__ ((__nonnull__ (m)))
+# else
+# define ATTRIBUTE_NONNULL(m)
+# endif /* GNUC >= 3.3 */
+#endif /* ATTRIBUTE_NONNULL */
+
+/* Attribute `returns_nonnull' was valid as of gcc 4.9. */
+#ifndef ATTRIBUTE_RETURNS_NONNULL
+# if (GCC_VERSION >= 4009)
+# define ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
+# else
+# define ATTRIBUTE_RETURNS_NONNULL
+# endif /* GNUC >= 4.9 */
+#endif /* ATTRIBUTE_RETURNS_NONNULL */
+
+/* Attribute `pure' was valid as of gcc 3.0. */
+#ifndef ATTRIBUTE_PURE
+# if (GCC_VERSION >= 3000)
+# define ATTRIBUTE_PURE __attribute__ ((__pure__))
+# else
+# define ATTRIBUTE_PURE
+# endif /* GNUC >= 3.0 */
+#endif /* ATTRIBUTE_PURE */
+
+/* Use ATTRIBUTE_PRINTF when the format specifier must not be NULL.
+ This was the case for the `printf' format attribute by itself
+ before GCC 3.3, but as of 3.3 we need to add the `nonnull'
+ attribute to retain this behavior. */
+#ifndef ATTRIBUTE_PRINTF
+#define ATTRIBUTE_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n))) ATTRIBUTE_NONNULL(m)
+#define ATTRIBUTE_PRINTF_1 ATTRIBUTE_PRINTF(1, 2)
+#define ATTRIBUTE_PRINTF_2 ATTRIBUTE_PRINTF(2, 3)
+#define ATTRIBUTE_PRINTF_3 ATTRIBUTE_PRINTF(3, 4)
+#define ATTRIBUTE_PRINTF_4 ATTRIBUTE_PRINTF(4, 5)
+#define ATTRIBUTE_PRINTF_5 ATTRIBUTE_PRINTF(5, 6)
+#endif /* ATTRIBUTE_PRINTF */
+
+/* Use ATTRIBUTE_FPTR_PRINTF when the format attribute is to be set on
+ a function pointer. Format attributes were allowed on function
+ pointers as of gcc 3.1. */
+#ifndef ATTRIBUTE_FPTR_PRINTF
+# if (GCC_VERSION >= 3001)
+# define ATTRIBUTE_FPTR_PRINTF(m, n) ATTRIBUTE_PRINTF(m, n)
+# else
+# define ATTRIBUTE_FPTR_PRINTF(m, n)
+# endif /* GNUC >= 3.1 */
+# define ATTRIBUTE_FPTR_PRINTF_1 ATTRIBUTE_FPTR_PRINTF(1, 2)
+# define ATTRIBUTE_FPTR_PRINTF_2 ATTRIBUTE_FPTR_PRINTF(2, 3)
+# define ATTRIBUTE_FPTR_PRINTF_3 ATTRIBUTE_FPTR_PRINTF(3, 4)
+# define ATTRIBUTE_FPTR_PRINTF_4 ATTRIBUTE_FPTR_PRINTF(4, 5)
+# define ATTRIBUTE_FPTR_PRINTF_5 ATTRIBUTE_FPTR_PRINTF(5, 6)
+#endif /* ATTRIBUTE_FPTR_PRINTF */
+
+/* Use ATTRIBUTE_NULL_PRINTF when the format specifier may be NULL. A
+ NULL format specifier was allowed as of gcc 3.3. */
+#ifndef ATTRIBUTE_NULL_PRINTF
+# if (GCC_VERSION >= 3003)
+# define ATTRIBUTE_NULL_PRINTF(m, n) __attribute__ ((__format__ (__printf__, m, n)))
+# else
+# define ATTRIBUTE_NULL_PRINTF(m, n)
+# endif /* GNUC >= 3.3 */
+# define ATTRIBUTE_NULL_PRINTF_1 ATTRIBUTE_NULL_PRINTF(1, 2)
+# define ATTRIBUTE_NULL_PRINTF_2 ATTRIBUTE_NULL_PRINTF(2, 3)
+# define ATTRIBUTE_NULL_PRINTF_3 ATTRIBUTE_NULL_PRINTF(3, 4)
+# define ATTRIBUTE_NULL_PRINTF_4 ATTRIBUTE_NULL_PRINTF(4, 5)
+# define ATTRIBUTE_NULL_PRINTF_5 ATTRIBUTE_NULL_PRINTF(5, 6)
+#endif /* ATTRIBUTE_NULL_PRINTF */
+
+/* Attribute `sentinel' was valid as of gcc 3.5. */
+#ifndef ATTRIBUTE_SENTINEL
+# if (GCC_VERSION >= 3005)
+# define ATTRIBUTE_SENTINEL __attribute__ ((__sentinel__))
+# else
+# define ATTRIBUTE_SENTINEL
+# endif /* GNUC >= 3.5 */
+#endif /* ATTRIBUTE_SENTINEL */
+
+
+#ifndef ATTRIBUTE_ALIGNED_ALIGNOF
+# if (GCC_VERSION >= 3000)
+# define ATTRIBUTE_ALIGNED_ALIGNOF(m) __attribute__ ((__aligned__ (__alignof__ (m))))
+# else
+# define ATTRIBUTE_ALIGNED_ALIGNOF(m)
+# endif /* GNUC >= 3.0 */
+#endif /* ATTRIBUTE_ALIGNED_ALIGNOF */
+
+/* Useful for structures whose layout must match some binary specification
+ regardless of the alignment and padding qualities of the compiler. */
+#ifndef ATTRIBUTE_PACKED
+# define ATTRIBUTE_PACKED __attribute__ ((packed))
+#endif