# define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#endif
+/* For compatibility with Clang's __has_builtin() */
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
/**
* __builtin_expect macros
*/
-#if !defined(__GNUC__)
+#if !defined(HAVE___BUILTIN_EXPECT)
# define __builtin_expect(x, y) (x)
#endif
#ifndef likely
-# ifdef __GNUC__
+# ifdef HAVE___BUILTIN_EXPECT
# define likely(x) __builtin_expect(!!(x), 1)
# define unlikely(x) __builtin_expect(!!(x), 0)
# else
* Unreachable macro. Useful for suppressing "control reaches end of non-void
* function" warnings.
*/
-#if __GNUC__ >= 4 && __GNUC_MINOR__ >= 5
+#ifdef HAVE___BUILTIN_UNREACHABLE
#define unreachable(str) \
do { \
assert(!str); \
__builtin_unreachable(); \
} while (0)
-#elif (defined(__clang__) && defined(__has_builtin))
-# if __has_builtin(__builtin_unreachable)
-# define unreachable(str) \
+#elif defined (_MSC_VER)
+#define unreachable(str) \
do { \
assert(!str); \
- __builtin_unreachable(); \
+ __assume(0); \
} while (0)
-# endif
+#else
+#define unreachable(str) assert(!str)
#endif
-#ifndef unreachable
-#define unreachable(str)
+/**
+ * Assume macro. Useful for expressing our assumptions to the compiler,
+ * typically for purposes of silencing warnings.
+ */
+#if __has_builtin(__builtin_assume)
+#define assume(expr) \
+do { \
+ assert(expr); \
+ __builtin_assume(expr); \
+} while (0)
+#elif defined HAVE___BUILTIN_UNREACHABLE
+#define assume(expr) ((expr) ? ((void) 0) \
+ : (assert(!"assumption failed"), \
+ __builtin_unreachable()))
+#elif defined (_MSC_VER)
+#define assume(expr) __assume(expr)
+#else
+#define assume(expr) assert(expr)
#endif
+/* Attribute const is used for functions that have no effects other than their
+ * return value, and only rely on the argument values to compute the return
+ * value. As a result, calls to it can be CSEed. Note that using memory
+ * pointed to by the arguments is not allowed for const functions.
+ */
+#ifdef HAVE_FUNC_ATTRIBUTE_CONST
+#define ATTRIBUTE_CONST __attribute__((__const__))
+#else
+#define ATTRIBUTE_CONST
+#endif
+
+#ifdef HAVE_FUNC_ATTRIBUTE_FLATTEN
+#define FLATTEN __attribute__((__flatten__))
+#else
+#define FLATTEN
+#endif
-#if (__GNUC__ >= 3)
+#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
#define PRINTFLIKE(f, a) __attribute__ ((format(__printf__, f, a)))
#else
#define PRINTFLIKE(f, a)
#endif
+#ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
+#define MALLOCLIKE __attribute__((__malloc__))
+#else
+#define MALLOCLIKE
+#endif
/* Used to optionally mark structures with misaligned elements or size as
* packed, to trade off performance for space.
*/
-#if (__GNUC__ >= 3)
+#ifdef HAVE_FUNC_ATTRIBUTE_PACKED
#define PACKED __attribute__((__packed__))
#else
#define PACKED
#endif
+/* Attribute pure is used for functions that have no effects other than their
+ * return value. As a result, calls to it can be dead code eliminated.
+ */
+#ifdef HAVE_FUNC_ATTRIBUTE_PURE
+#define ATTRIBUTE_PURE __attribute__((__pure__))
+#else
+#define ATTRIBUTE_PURE
+#endif
#ifdef __cplusplus
/**
# endif
#endif
+/**
+ * PUBLIC/USED macros
+ *
+ * If we build the library with gcc's -fvisibility=hidden flag, we'll
+ * use the PUBLIC macro to mark functions that are to be exported.
+ *
+ * We also need to define a USED attribute, so the optimizer doesn't
+ * inline a static function that we later use in an alias. - ajax
+ */
+#ifndef PUBLIC
+# if defined(__GNUC__) || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x590))
+# define PUBLIC __attribute__((visibility("default")))
+# define USED __attribute__((used))
+# elif defined(_MSC_VER)
+# define PUBLIC __declspec(dllexport)
+# define USED
+# else
+# define PUBLIC
+# define USED
+# endif
+#endif
+
+#ifdef HAVE_FUNC_ATTRIBUTE_UNUSED
+#define UNUSED __attribute__((unused))
+#else
+#define UNUSED
+#endif
+
+#ifdef HAVE_FUNC_ATTRIBUTE_WARN_UNUSED_RESULT
+#define MUST_CHECK __attribute__((warn_unused_result))
+#else
+#define MUST_CHECK
+#endif
+
+/** Compute ceiling of integer quotient of A divided by B. */
+#define DIV_ROUND_UP( A, B ) ( (A) % (B) == 0 ? (A)/(B) : (A)/(B)+1 )
+
#endif /* UTIL_MACROS_H */