convenience SIG_ATOMIC_T macro definition
diff --git a/ares/setup_once.h b/ares/setup_once.h
index 083fdbc..c80fc32 100644
--- a/ares/setup_once.h
+++ b/ares/setup_once.h
@@ -213,6 +213,17 @@
/*
+ * Convenience SIG_ATOMIC_T definition
+ */
+
+#ifdef HAVE_SIG_ATOMIC_T_VOLATILE
+#define SIG_ATOMIC_T static sig_atomic_t
+#else
+#define SIG_ATOMIC_T static volatile sig_atomic_t
+#endif
+
+
+/*
* Default return type for signal handlers.
*/
diff --git a/lib/setup_once.h b/lib/setup_once.h
index 03141a4..4bbde0e 100644
--- a/lib/setup_once.h
+++ b/lib/setup_once.h
@@ -220,6 +220,17 @@
/*
+ * Convenience SIG_ATOMIC_T definition
+ */
+
+#ifdef HAVE_SIG_ATOMIC_T_VOLATILE
+#define SIG_ATOMIC_T static sig_atomic_t
+#else
+#define SIG_ATOMIC_T static volatile sig_atomic_t
+#endif
+
+
+/*
* Default return type for signal handlers.
*/
