[PATCH 4/8] lib: Add prototype declarations in lib/clz_ctz.c

From: Rashika Kheria
Date: Tue Feb 25 2014 - 02:46:32 EST


Add prototype declarations of functions in lib/clz_ctz.c. These
functions are required by GCC builtins and hence can not be removed
despite of their unreferenced appearance in kernel source.

This eliminates the following warning in lib/clz_ctz.c:
lib/clz_ctz.c:16:12: warning: no previous prototype for â__ctzsi2â [-Wmissing-prototypes]
lib/clz_ctz.c:22:12: warning: no previous prototype for â__clzsi2â [-Wmissing-prototypes]
lib/clz_ctz.c:44:12: warning: no previous prototype for â__clzdi2â [-Wmissing-prototypes]
lib/clz_ctz.c:50:12: warning: no previous prototype for â__ctzdi2â [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@xxxxxxxxx>
Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
lib/clz_ctz.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/lib/clz_ctz.c b/lib/clz_ctz.c
index a8f8379..2e11e48 100644
--- a/lib/clz_ctz.c
+++ b/lib/clz_ctz.c
@@ -6,6 +6,9 @@
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
+ * The functions in this file aren't called directly, but are required by
+ * GCC builtins such as __builtin_ctz, and therefore they can't be removed
+ * despite appearing unreferenced in kernel source.
*
* __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
*/
@@ -13,18 +16,22 @@
#include <linux/export.h>
#include <linux/kernel.h>

+int __weak __ctzsi2(int val);
int __weak __ctzsi2(int val)
{
return __ffs(val);
}
EXPORT_SYMBOL(__ctzsi2);

+int __weak __clzsi2(int val);
int __weak __clzsi2(int val)
{
return 32 - fls(val);
}
EXPORT_SYMBOL(__clzsi2);

+int __weak __clzdi2(long val);
+int __weak __ctzdi2(long val);
#if BITS_PER_LONG == 32

int __weak __clzdi2(long val)
--
1.7.9.5

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