use _GNU_SOURCE instead of __USE_GNU

diff --git a/cmd/dot/dot.c b/cmd/dot/dot.c
index 7a473952ae15227e50b8f5ff44389b4eb27a05b4..702c6ffdf5a99be072412f994b8a264e818b9c41 100644 (file)
--- a/cmd/dot/dot.c
+++ b/cmd/dot/dot.c
@@ -31,9 +31,9 @@
 #endif
 
 #if defined(HAVE_FENV_H) && defined(HAVE_FEENABLEEXCEPT)
-/* __USE_GNU is needed for feenableexcept to be defined in fenv.h on GNU
+/* _GNU_SOURCE is needed for feenableexcept to be defined in fenv.h on GNU
  * systems.   Presumably it will do no harm on other systems. */
-#define __USE_GNU
+#define _GNU_SOURCE
 # include <fenv.h>
 #elif HAVE_FPU_CONTROL_H
 # include <fpu_control.h>