+# define __has_attribute(a) __has_attribute_##a
+# define __has_attribute_alloc_size (4 < __GNUC__ + (3 <= __GNUC_MINOR__))
+# define __has_attribute_cleanup (3 < __GNUC__ + (4 <= __GNUC_MINOR__))
+# define __has_attribute_externally_visible \
+ (4 < __GNUC__ + (1 <= __GNUC_MINOR__))
+# define __has_attribute_no_address_safety_analysis false
+# define __has_attribute_no_sanitize_address \
+ (4 < __GNUC__ + (8 <= __GNUC_MINOR__))
+#endif
+
+/* Simulate __has_feature on compilers that lack it. It is used only
+ to define ADDRESS_SANITIZER below. */