+/* Call argument flags. */
+
+/* Nonzero if the argument is not dereferenced recursively, thus only
+ directly reachable memory is read or written. */
+#define EAF_DIRECT (1 << 0)
+/* Nonzero if memory reached by the argument is not clobbered. */
+#define EAF_NOCLOBBER (1 << 1)
+/* Nonzero if the argument does not escape. */
+#define EAF_NOESCAPE (1 << 2)
+/* Nonzero if the argument is not used by the function. */
+#define EAF_UNUSED (1 << 3)
+
+/* Call return flags. */
+
+/* Mask for the argument number that is returned. Lower two bits of
+ the return flags, encodes argument slots zero to three. */
+#define ERF_RETURN_ARG_MASK (3)
+/* Nonzero if the return value is equal to the argument number
+ flags & ERF_RETURN_ARG_MASK. */
+#define ERF_RETURNS_ARG (1 << 2)
+/* Nonzero if the return value does not alias with anything. Functions
+ with the malloc attribute have this set on their return value. */
+#define ERF_NOALIAS (1 << 3)
+