Re: [PATCH v2] module: LLVMLinux: Remove unused function warning from __param_check macro

From: Behan Webster
Date: Fri Mar 07 2014 - 21:22:02 EST


On 03/07/14 18:17, Joe Perches wrote:
On Fri, 2014-03-07 at 18:10 -0800, behanw@xxxxxxxxxxxxxxxxxx wrote:
This code makes a compile time type check that is optimized away. Clang
complains that it generates an unused function.
[]
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
[]
@@ -346,7 +346,7 @@ static inline void destroy_params(const struct kernel_param *params,
/* The macros to do compile-time type checking stolen from Jakub
Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
#define __param_check(name, p, type) \
- static inline type *__check_##name(void) { return(p); }
+ static inline __always_unused type *__check_##name(void) { return(p); }
Perhaps __maybe_unused ?
I thought about that (and even tested with __maybe_unused), but I *think* they are always unused, except at compile time (see comment above). Though I could be wrong.

I'm certainly okay with __maybe_unused if that is preferable.

Behan

--
Behan Webster
behanw@xxxxxxxxxxxxxxxxxx

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