[PATCH 4.4 01/31] compiler, clang: suppress warning for unused static inline functions
From: Greg Kroah-Hartman
Date: Fri Jul 20 2018 - 08:26:47 EST
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Rientjes <rientjes@xxxxxxxxxx>
commit abb2ea7dfd82451d85ce669b811310c05ab5ca46 upstream.
GCC explicitly does not warn for unused static inline functions for
-Wunused-function. The manual states:
Warn whenever a static function is declared but not defined or
a non-inline static function is unused.
Clang does warn for static inline functions that are unused.
It turns out that suppressing the warnings avoids potentially complex
#ifdef directives, which also reduces LOC.
Suppress the warning for clang.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/compiler-clang.h | 7 +++++++
1 file changed, 7 insertions(+)
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -15,3 +15,10 @@
* with any version that can compile the kernel
*/
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
+
+/*
+ * GCC does not warn about unused static inline functions for
+ * -Wunused-function. This turns out to avoid the need for complex #ifdef
+ * directives. Suppress the warning in clang as well.
+ */
+#define inline inline __attribute__((unused))