#ifndef UTIL_MACROS_H
#define UTIL_MACROS_H
+#include <assert.h>
+
/* Compute the size of an array */
#ifndef ARRAY_SIZE
# 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
assert(!str); \
__builtin_unreachable(); \
} while (0)
-#elif _MSC_VER >= 1200
+#elif defined (_MSC_VER)
#define unreachable(str) \
do { \
assert(!str); \
__assume(0); \
} while (0)
-#endif
-
-#ifndef unreachable
-#define unreachable(str)
+#else
+#define unreachable(str) assert(!str)
#endif
/**
* Assume macro. Useful for expressing our assumptions to the compiler,
* typically for purposes of silencing warnings.
*/
-#ifdef HAVE___BUILTIN_UNREACHABLE
+#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 _MSC_VER >= 1200
+#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 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
/**
* Macro function that evaluates to true if T is a trivially
# 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__)
+# 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 */