+/**
+ * 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 )
+