+
+#if __GNUC__ >= 3
+/* Assume that a flexible array member at the end of a struct
+ * can be defined thus: T arr[]; */
+#define FLEXIBLE_ARRAY
+#else
+/* Assume that it must be defined thus: T arr[0]; */
+#define FLEXIBLE_ARRAY 0
+#endif
+
+#if defined(SMP) || defined(THREADED_RTS)
+#define RTS_SUPPORTS_THREADS 1
+#endif
+
+/* Some macros to handle DLLing (Win32 only at the moment). */
+#include "StgDLL.h"
+
+/* Fix for mingw stat problem (done here so it's early enough) */
+#ifdef mingw32_TARGET_OS
+#define __MSVCRT__ 1
+#endif
+
+/* Turn lazy blackholing and eager blackholing on/off.
+ *
+ * Using eager blackholing makes things easier to debug because
+ * the blackholes are more predictable - but it's slower and less sexy.
+ *
+ * For now, do lazy and not eager.
+ */
+
+/* TICKY_TICKY needs EAGER_BLACKHOLING to verify no double-entries of
+ * single-entry thunks.
+ *
+ * SMP needs EAGER_BLACKHOLING because it has to lock thunks
+ * synchronously, in case another thread is trying to evaluate the
+ * same thunk simultaneously.
+ */
+#if defined(SMP) || defined(TICKY_TICKY)
+# define EAGER_BLACKHOLING
+#else
+# define LAZY_BLACKHOLING