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[PATCH] Add const attr to gnu_dev_{major,minor,makedev}
- From: Marek Polacek <mpolacek at redhat dot com>
- To: libc-alpha <libc-alpha at sourceware dot org>
- Date: Tue, 12 Jul 2011 14:23:46 +0200
- Subject: [PATCH] Add const attr to gnu_dev_{major,minor,makedev}
gnu_dev_{major,minor,makedev} do not examine any values except their
arguments and moreover, they do not read any global variable. Thus
we might mark them as `const'.
2011-07-12 Marek Polacek <mpolacek@redhat.com>
* misc/sys/cdefs.h: Add support for const attribute.
* sysdeps/unix/sysv/linux/sys/sysmacros.h: Add __attribute_const__
to gnu_dev_{major,minor,makedev} functions.
--- libc/sysdeps/unix/sysv/linux/sys/sysmacros.h.mp 2011-07-11 11:38:57.865575287 +0200
+++ libc/sysdeps/unix/sysv/linux/sys/sysmacros.h 2011-07-12 13:52:30.411146608 +0200
@@ -31,29 +31,29 @@ __BEGIN_DECLS
__extension__
extern unsigned int gnu_dev_major (unsigned long long int __dev)
- __THROW;
+ __THROW __attribute_const__;
__extension__
extern unsigned int gnu_dev_minor (unsigned long long int __dev)
- __THROW;
+ __THROW __attribute_const__;
__extension__
extern unsigned long long int gnu_dev_makedev (unsigned int __major,
unsigned int __minor)
- __THROW;
+ __THROW __attribute_const__;
# if defined __GNUC__ && __GNUC__ >= 2 && defined __USE_EXTERN_INLINES
-__extension__ __extern_inline unsigned int
+__extension__ __extern_inline __attribute_const__ unsigned int
__NTH (gnu_dev_major (unsigned long long int __dev))
{
return ((__dev >> 8) & 0xfff) | ((unsigned int) (__dev >> 32) & ~0xfff);
}
-__extension__ __extern_inline unsigned int
+__extension__ __extern_inline __attribute_const__ unsigned int
__NTH (gnu_dev_minor (unsigned long long int __dev))
{
return (__dev & 0xff) | ((unsigned int) (__dev >> 12) & ~0xff);
}
-__extension__ __extern_inline unsigned long long int
+__extension__ __extern_inline __attribute_const__ unsigned long long int
__NTH (gnu_dev_makedev (unsigned int __major, unsigned int __minor))
{
return ((__minor & 0xff) | ((__major & 0xfff) << 8)
--- libc/misc/sys/cdefs.h.mp 2011-07-11 12:00:25.531575421 +0200
+++ libc/misc/sys/cdefs.h 2011-07-12 14:18:54.419671839 +0200
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992-2001, 2002, 2004, 2005, 2006, 2007, 2009
+/* Copyright (C) 1992-2001, 2002, 2004, 2005, 2006, 2007, 2009, 2011
Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -218,6 +218,13 @@
# define __attribute_pure__ /* Ignore */
#endif
+/* This declaration tells the compiler that the value is constant. */
+#if __GNUC_PREREQ (2,5)
+# define __attribute_const__ __attribute__ ((__const__))
+#else
+# define __attribute_const__ /* Ignore */
+#endif
+
/* At some point during the gcc 3.1 development the `used' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings. */