-extern ecdsa_t *ecdsa_generate(void) __attribute__ ((__malloc__));
-extern bool ecdsa_write_pem_public_key(ecdsa_t *ecdsa, FILE *fp) __attribute__ ((__warn_unused_result__));
-extern bool ecdsa_write_pem_private_key(ecdsa_t *ecdsa, FILE *fp) __attribute__ ((__warn_unused_result__));
+extern ecdsa_t *ecdsa_generate(void) ATTR_MALLOC;
+extern bool ecdsa_write_pem_public_key(ecdsa_t *ecdsa, FILE *fp) ATTR_WARN_UNUSED;
+extern bool ecdsa_write_pem_private_key(ecdsa_t *ecdsa, FILE *fp) ATTR_WARN_UNUSED;