Re: [PATCH] LLVMLinux: Remove warning about returning an uninitialized variable

["H. Peter Anvin" <hpa@zytor.com>]

On 03/21/2014 11:38 PM, behanw@converseincode.com wrote:
> From: Behan Webster <behanw@converseincode.com>
> 
> Fix uninitialized return code in default case in cmpxchg-local.h
> 
> This patch fixes the code to prevent an uninitialized return value that is detected
> when compiling with clang. The bug produces numerous warnings when compiling the
> Linux kernel with clang.
> 
> Signed-off-by: Behan Webster <behanw@converseincode.com>
> Signed-off-by: Mark Charlebois <charlebm@gmail.com>
> ---
>  include/asm-generic/cmpxchg-local.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/asm-generic/cmpxchg-local.h b/include/asm-generic/cmpxchg-local.h
> index d8d4c89..4c41bb8 100644
> --- a/include/asm-generic/cmpxchg-local.h
> +++ b/include/asm-generic/cmpxchg-local.h
> @@ -41,6 +41,7 @@ static inline unsigned long __cmpxchg_local_generic(volatile void *ptr,
>  		break;
>  	default:
>  		wrong_size_cmpxchg(ptr);
> +		prev = 0;
>  	}
>  	raw_local_irq_restore(flags);
>  	return prev;
> 

Shouldn't this be a build time assert (__compiletime_error())?

	-hpa