Module Name: src
Committed By: christos
Date: Wed Feb 8 16:13:04 UTC 2017
Modified Files:
src/sys/sys: cdefs.h
Log Message:
add __empty
To generate a diff of this commit:
cvs rdiff -u -r1.129 -r1.130 src/sys/sys/cdefs.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/sys/cdefs.h
diff -u src/sys/sys/cdefs.h:1.129 src/sys/sys/cdefs.h:1.130
--- src/sys/sys/cdefs.h:1.129 Tue Dec 27 16:52:01 2016
+++ src/sys/sys/cdefs.h Wed Feb 8 11:13:04 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: cdefs.h,v 1.129 2016/12/27 21:52:01 christos Exp $ */
+/* $NetBSD: cdefs.h,v 1.130 2017/02/08 16:13:04 christos Exp $ */
/* * Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
@@ -306,6 +306,20 @@
#define __unreachable() do {} while (/*CONSTCOND*/0)
#endif
+/*
+ * To be used when an empty body is required like:
+ *
+ * #ifdef DEBUG
+ * # define dprintf(a) printf(a)
+ * #else
+ * # define dprintf(a) __empty
+ * #endif
+ *
+ * We use ((void)0) instead of do {} while (/*CONSTCOND*/0) so that it
+ * works on , expressions.
+ */
+#define __empty ((void)0)
+
#if defined(__cplusplus)
#define __BEGIN_EXTERN_C extern "C" {
#define __END_EXTERN_C }
