Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH v3] module: LLVMLinux: Remove unused function warning from __param_check macro | Date | Mon, 17 Mar 2014 13:17:52 +1030 |
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behanw@converseincode.com writes: > From: Mark Charlebois <charlebm@gmail.com> > > This code makes a compile time type check that is optimized away. Clang > complains that it generates an unused function:
Thanks, applied.
Cheers, Rusty.
> > linux/kernel/panic.c:471:1: warning: unused function '__check_panic' > [-Wunused-function] > core_param(panic, panic_timeout, int, 0644); > ^ > linux/moduleparam.h:283:2: note: expanded from macro > 'core_param' > param_check_##type(name, &(var)); \ > ^ > <scratch space>:87:1: note: expanded from here > param_check_int > ^ > linux/moduleparam.h:369:34: note: expanded from macro > 'param_check_int' > #define param_check_int(name, p) __param_check(name, p, int) > ^ > linux/moduleparam.h:349:22: note: expanded from macro > '__param_check' > static inline type *__check_##name(void) { return(p); } > ^ > <scratch space>:88:1: note: expanded from here > __check_panic > > GCC won't complain for a static inline function but would if it was just > a static function. > > Adding the unused attribute to the function declaration removes the warning. > Per request from Rusty Russell it is marked as __always_unused as the code > is meant to be optimized away. > > This code works for both GCC and clang. > > Signed-off-by: Mark Charlebois <charlebm@gmail.com> > Signed-off-by: Behan Webster <behanw@converseincode.com> > --- > include/linux/moduleparam.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h > index c3eb102..175f699 100644 > --- 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 type __always_unused *__check_##name(void) { return(p); } > > extern struct kernel_param_ops param_ops_byte; > extern int param_set_byte(const char *val, const struct kernel_param *kp); > -- > 1.8.3.2
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