+/* GCC always provides __builtin_alloca(x). */
+#undef alloca
+#define alloca(x) __builtin_alloca(x)
+
+#ifdef ENABLE_RUNTIME_CHECKING
+#define gcc_assert(EXPR) ((void)(!(EXPR) ? abort (), 0 : 0))
+#else
+/* Include EXPR, so that unused variable warnings do not occur. */
+#define gcc_assert(EXPR) ((void)(0 && (EXPR)))
+#endif
+/* Use gcc_unreachable() to mark unreachable locations (like an
+ unreachable default case of a switch. Do not use gcc_assert(0). */
+#define gcc_unreachable() (abort ())
+
+/* Filename handling macros. */
+#include "filenames.h"
+