+/* Define macros for some gcc attributes. This permits us to use the
+ macros freely, and know that they will come into play for the
+ version of gcc in which they are supported. */
+
+#if (GCC_VERSION < 2007)
+# define __attribute__(x)
+#endif
+
+/* Attribute __malloc__ on functions was valid as of gcc 2.96. */
+#ifndef ATTRIBUTE_MALLOC
+# if (GCC_VERSION >= 2096)
+# define ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
+# else
+# define ATTRIBUTE_MALLOC
+# endif /* GNUC >= 2.96 */
+#endif /* ATTRIBUTE_MALLOC */
+
+/* Attributes on labels were valid as of gcc 2.93 and g++ 4.5. For
+ g++ an attribute on a label must be followed by a semicolon. */
+#ifndef ATTRIBUTE_UNUSED_LABEL
+# ifndef __cplusplus
+# if GCC_VERSION >= 2093
+# define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED
+# else
+# define ATTRIBUTE_UNUSED_LABEL
+# endif
+# else
+# if GCC_VERSION >= 4005
+# define ATTRIBUTE_UNUSED_LABEL ATTRIBUTE_UNUSED ;
+# else
+# define ATTRIBUTE_UNUSED_LABEL
+# endif
+# endif
+#endif
+
+/* 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
+
+/* Attribute `hot' and `cold' was valid as of gcc 4.3. */
+#ifndef ATTRIBUTE_COLD
+# if (GCC_VERSION >= 4003)
+# define ATTRIBUTE_COLD __attribute__ ((__cold__))
+# else
+# define ATTRIBUTE_COLD
+# endif /* GNUC >= 4.3 */
+#endif /* ATTRIBUTE_COLD */
+#ifndef ATTRIBUTE_HOT
+# if (GCC_VERSION >= 4003)
+# define ATTRIBUTE_HOT __attribute__ ((__hot__))
+# else
+# define ATTRIBUTE_HOT
+# endif /* GNUC >= 4.3 */
+#endif /* ATTRIBUTE_HOT */
+
+/* Attribute 'no_sanitize_undefined' was valid as of gcc 4.9. */
+#ifndef ATTRIBUTE_NO_SANITIZE_UNDEFINED
+# if (GCC_VERSION >= 4009)
+# define ATTRIBUTE_NO_SANITIZE_UNDEFINED __attribute__ ((no_sanitize_undefined))
+# else
+# define ATTRIBUTE_NO_SANITIZE_UNDEFINED
+# endif /* GNUC >= 4.9 */
+#endif /* ATTRIBUTE_NO_SANITIZE_UNDEFINED */
+
+/* Attribute 'nonstring' was valid as of gcc 8. */
+#ifndef ATTRIBUTE_NONSTRING
+# if GCC_VERSION >= 8000
+# define ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__))
+# else
+# define ATTRIBUTE_NONSTRING
+# endif
+#endif
+
+/* Attribute `alloc_size' was valid as of gcc 4.3. */
+#ifndef ATTRIBUTE_RESULT_SIZE_1
+# if (GCC_VERSION >= 4003)
+# define ATTRIBUTE_RESULT_SIZE_1 __attribute__ ((alloc_size (1)))
+# else
+# define ATTRIBUTE_RESULT_SIZE_1
+#endif
+#endif
+
+#ifndef ATTRIBUTE_RESULT_SIZE_2
+# if (GCC_VERSION >= 4003)
+# define ATTRIBUTE_RESULT_SIZE_2 __attribute__ ((alloc_size (2)))
+# else
+# define ATTRIBUTE_RESULT_SIZE_2
+#endif
+#endif
+
+#ifndef ATTRIBUTE_RESULT_SIZE_1_2
+# if (GCC_VERSION >= 4003)
+# define ATTRIBUTE_RESULT_SIZE_1_2 __attribute__ ((alloc_size (1, 2)))
+# else
+# define ATTRIBUTE_RESULT_SIZE_1_2
+#endif
+#endif
+
+/* Attribute `warn_unused_result' was valid as of gcc 3.3. */
+#ifndef ATTRIBUTE_WARN_UNUSED_RESULT
+# if GCC_VERSION >= 3003
+# define ATTRIBUTE_WARN_UNUSED_RESULT __attribute__ ((warn_unused_result))
+# else
+# define ATTRIBUTE_WARN_UNUSED_RESULT
+# endif
+#endif
+
+/* We use __extension__ in some places to suppress -pedantic warnings
+ about GCC extensions. This feature didn't work properly before
+ gcc 2.8. */
+#if GCC_VERSION < 2008
+#define __extension__
+#endif
+
+/* This is used to declare a const variable which should be visible
+ outside of the current compilation unit. Use it as
+ EXPORTED_CONST int i = 1;
+ This is because the semantics of const are different in C and C++.
+ "extern const" is permitted in C but it looks strange, and gcc
+ warns about it when -Wc++-compat is not used. */
+#ifdef __cplusplus
+#define EXPORTED_CONST extern const
+#else
+#define EXPORTED_CONST const
+#endif
+
+/* Be conservative and only use enum bitfields with C++ or GCC.
+ FIXME: provide a complete autoconf test for buggy enum bitfields. */
+
+#ifdef __cplusplus
+#define ENUM_BITFIELD(TYPE) enum TYPE
+#elif (GCC_VERSION > 2000)
+#define ENUM_BITFIELD(TYPE) __extension__ enum TYPE
+#else
+#define ENUM_BITFIELD(TYPE) unsigned int
+#endif
+
+#if __cpp_constexpr >= 200704
+#define CONSTEXPR constexpr
+#else
+#define CONSTEXPR
+#endif
+
+/* C++11 adds the ability to add "override" after an implementation of a
+ virtual function in a subclass, to:
+ (A) document that this is an override of a virtual function
+ (B) allow the compiler to issue a warning if it isn't (e.g. a mismatch
+ of the type signature).
+
+ Similarly, it allows us to add a "final" to indicate that no subclass
+ may subsequently override the vfunc.
+
+ Provide OVERRIDE and FINAL as macros, allowing us to get these benefits
+ when compiling with C++11 support, but without requiring C++11.
+
+ For gcc, use "-std=c++11" to enable C++11 support; gcc 6 onwards enables
+ this by default (actually GNU++14). */
+
+#if defined __cplusplus
+# if __cplusplus >= 201103
+ /* C++11 claims to be available: use it. Final/override were only
+ implemented in 4.7, though. */
+# if GCC_VERSION < 4007
+# define OVERRIDE
+# define FINAL
+# else
+# define OVERRIDE override
+# define FINAL final
+# endif
+# elif GCC_VERSION >= 4007
+ /* G++ 4.7 supports __final in C++98. */
+# define OVERRIDE
+# define FINAL __final
+# else
+ /* No C++11 support; leave the macros empty. */
+# define OVERRIDE
+# define FINAL
+# endif
+#else
+ /* No C++11 support; leave the macros empty. */
+# define OVERRIDE
+# define FINAL
+#endif
+
+/* A macro to disable the copy constructor and assignment operator.
+ When building with C++11 and above, the methods are explicitly
+ deleted, causing a compile-time error if something tries to copy.
+ For C++03, this just declares the methods, causing a link-time
+ error if the methods end up called (assuming you don't
+ define them). For C++03, for best results, place the macro
+ under the private: access specifier, like this,
+
+ class name_lookup
+ {
+ private:
+ DISABLE_COPY_AND_ASSIGN (name_lookup);
+ };
+
+ so that most attempts at copy are caught at compile-time. */
+
+#if __cplusplus >= 201103
+#define DISABLE_COPY_AND_ASSIGN(TYPE) \
+ TYPE (const TYPE&) = delete; \
+ void operator= (const TYPE &) = delete
+ #else
+#define DISABLE_COPY_AND_ASSIGN(TYPE) \
+ TYPE (const TYPE&); \
+ void operator= (const TYPE &)
+#endif /* __cplusplus >= 201103 */
+
+#ifdef __cplusplus
+}
+#endif
+