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authorLi Zefan <lizf@cn.fujitsu.com>2009-11-02 03:50:52 +0300
committerIngo Molnar <mingo@elte.hu>2009-11-02 17:47:54 +0300
commit7b2a35132ad0a70902dcd2844c27ed64cda0ce9b (patch)
treef800a7d536d7850ac5cfeca5eb576f9af568751d
parentc4b8ac2c1aee1398b9378b8730bac56294b3410b (diff)
downloadlinux-7b2a35132ad0a70902dcd2844c27ed64cda0ce9b.tar.xz
compiler: Introduce __always_unused
I wrote some code which is used as compile-time checker, and the code should be elided after compile. So I need to annotate the code as "always unused", compared to "maybe unused". Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4AEE2CEC.8040206@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/compiler-gcc.h1
-rw-r--r--include/linux/compiler.h4
2 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index a3ed7cb8ca34..73dcf804bc94 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -79,6 +79,7 @@
#define noinline __attribute__((noinline))
#define __attribute_const__ __attribute__((__const__))
#define __maybe_unused __attribute__((unused))
+#define __always_unused __attribute__((unused))
#define __gcc_header(x) #x
#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 04fb5135b4e1..7947f4f6fa51 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -213,6 +213,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
# define __maybe_unused /* unimplemented */
#endif
+#ifndef __always_unused
+# define __always_unused /* unimplemented */
+#endif
+
#ifndef noinline
#define noinline
#endif