From mboxrd@z Thu Jan  1 00:00:00 1970
From: Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH v4 9/9] bug.h: Convert BUILD_BUG{,_ON} to use
 BUILD_BUG_ON_MSG
Date: Tue, 30 Oct 2012 20:19:05 +0100
Message-ID: <20121030191905.GG28499@liondog.tnic>
References: <1351457648-7453-1-git-send-email-daniel.santos@pobox.com>
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Cc: LKML <linux-kernel@vger.kernel.org>, Andi Kleen <ak@linux.intel.com>, Andrea Arcangeli <aarcange@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Christopher Li <sparse@chrisli.org>, Daniel Santos <daniel.santos@pobox.com>, David Daney <david.daney@cavium.com>, David Howells <dhowells@redhat.com>, Joe Perches <joe@perches.com>, Josh Triplett <josh@joshtriplett.org>, Konstantin Khlebnikov <khlebnikov@openvz.org>, linux-sparse@vger.kernel.org, Michel Lespinasse <walken@google.com>, Paul Gortmaker <paul.gortmaker@windriver.com>, Pavel Pisa <pisa@cmp.felk.cvut.cz>, Peter Zijlstra <a.p.zijlstra@chello.nl>, Steven Rostedt <rostedt@goodmis.org>, David Rientjes <rientjes@google.com>
List-Id: linux-sparse@vger.kernel.org

On Sun, Oct 28, 2012 at 03:57:15PM -0500, danielfsantos@att.net wrote:
> Remove duplicate code by converting BUILD_BUG and BUILD_BUG_ON to just
> call BUILD_BUG_ON_MSG.  This not only reduces source code bloat, but
> also prevents the possibility of code being changed for one macro and
> not for the other (which was previously the case for BUILD_BUG and
> BUILD_BUG_ON).
> 
> Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
> ---
>  include/linux/bug.h |   17 +++--------------
>  1 files changed, 3 insertions(+), 14 deletions(-)
> 
> diff --git a/include/linux/bug.h b/include/linux/bug.h
> index 3bc1ddf..b58ba51 100644
> --- a/include/linux/bug.h
> +++ b/include/linux/bug.h
> @@ -81,14 +81,8 @@ struct pt_regs;
>  #ifndef __OPTIMIZE__
>  #define BUILD_BUG_ON(condition) __compiletime_error_fallback(condition)
>  #else
> -#define BUILD_BUG_ON(condition)						\
> -	do {								\
> -		extern void __build_bug_on_failed(void)			\
> -			__compiletime_error("BUILD_BUG_ON failed");	\
> -		__compiletime_error_fallback(condition);		\
> -		if (condition)						\
> -			__build_bug_on_failed();			\
> -	} while(0)
> +#define BUILD_BUG_ON(condition) \
> +	BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)

Concatenating "condition" might not be very informative in all cases.
For example:

BUILD_BUG_ON(1);

Having __LINE__ is good enough IMHO.

Thanks.

-- 
Regards/Gruss,
    Boris.