Module Name: src
Committed By: apb
Date: Fri Oct 25 08:47:30 UTC 2013
Modified Files:
src/sys/sys: cdefs.h
Log Message:
Add comments explaining what __unused and __used are for.
To generate a diff of this commit:
cvs rdiff -u -r1.113 -r1.114 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:1.113 src/sys/sys/cdefs.h:1.114
--- src/sys/sys/cdefs.h:1.113 Wed Oct 16 19:31:43 2013
+++ src/sys/sys/cdefs.h Fri Oct 25 08:47:30 2013
@@ -1,4 +1,4 @@
-/* $NetBSD: cdefs.h,v 1.113 2013/10/16 19:31:43 christos Exp $ */
+/* $NetBSD: cdefs.h,v 1.114 2013/10/25 08:47:30 apb Exp $ */
/*
* Copyright (c) 1991, 1993
@@ -250,12 +250,21 @@
#define __noclone /* nothing */
#endif
+/*
+ * __unused: Note that variable might be unused.
+ * Do not warn if variable is unused.
+ */
#if __GNUC_PREREQ__(2, 7)
#define __unused __attribute__((__unused__))
#else
#define __unused /* delete */
#endif
+/*
+ * __used: Note that variable is needed, even if it appears to be unused.
+ * Valid only for static variables. Do not optimise variable away.
+ * Do not warn if variable is unused.
+ */
#if __GNUC_PREREQ__(3, 1)
#define __used __attribute__((__used__))
#else
