Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964822Ab2JEU7H (ORCPT ); Fri, 5 Oct 2012 16:59:07 -0400 Received: from mail.skyhub.de ([78.46.96.112]:42565 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964786Ab2JEU7D (ORCPT ); Fri, 5 Oct 2012 16:59:03 -0400 Date: Fri, 5 Oct 2012 22:58:58 +0200 From: Borislav Petkov To: danielfsantos@att.net Cc: LKML , Andi Kleen , Andrea Arcangeli , Andrew Morton , Christopher Li , David Daney , David Howells , David Rientjes , Joe Perches , Konstantin Khlebnikov , linux-sparse@vger.kernel.org, Michel Lespinasse , Paul Gortmaker , Pavel Pisa , Peter Zijlstra , Steven Rostedt , Daniel Santos Subject: Re: [PATCH v2 09/10] bug.h: Add BUILD_BUG_ON_MSG & BUILD_BUG_INTERNAL{,2} Message-ID: <20121005205858.GB28452@liondog.tnic> Mail-Followup-To: Borislav Petkov , danielfsantos@att.net, LKML , Andi Kleen , Andrea Arcangeli , Andrew Morton , Christopher Li , David Daney , David Howells , David Rientjes , Joe Perches , Konstantin Khlebnikov , linux-sparse@vger.kernel.org, Michel Lespinasse , Paul Gortmaker , Pavel Pisa , Peter Zijlstra , Steven Rostedt , Daniel Santos References: <1349465759-20524-1-git-send-email-daniel.santos@pobox.com> <1349466169-20637-9-git-send-email-daniel.santos@pobox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1349466169-20637-9-git-send-email-daniel.santos@pobox.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2816 Lines: 82 On Fri, Oct 05, 2012 at 02:42:48PM -0500, danielfsantos@att.net wrote: > Add BUILD_BUG_ON_MSG which behaves like BUILD_BUG_ON (with optimizations > turned enabled), except that it allows you to specify the error message > you want emitted as the third parameter. Under the hood, this relies on > BUILD_BUG_INTERNAL{,2}, which does the actual work and is pretty-much > identical to BUILD_BUG_ON. > > Signed-off-by: Daniel Santos > --- > include/linux/bug.h | 26 ++++++++++++++++++++++++++ > 1 files changed, 26 insertions(+), 0 deletions(-) > > diff --git a/include/linux/bug.h b/include/linux/bug.h > index 1b43ea2..91bd9d5 100644 > --- a/include/linux/bug.h > +++ b/include/linux/bug.h > @@ -16,6 +16,7 @@ struct pt_regs; > #define BUILD_BUG_ON_NOT_POWER_OF_2(n) > #define BUILD_BUG_ON_ZERO(e) (0) > #define BUILD_BUG_ON_NULL(e) ((void*)0) > +#define BUILD_BUG_ON_MSG(cond, msg) (0) > #define BUILD_BUG_ON(condition) (0) > #define BUILD_BUG() (0) > #else /* __CHECKER__ */ > @@ -38,6 +39,31 @@ struct pt_regs; > */ > #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) > > +#define _CONCAT1(a, b) a##b > +#define CONCAT(a, b) _CONCAT1(a, b) Let's call the indirection _CONCAT without the "1". > +#define UNIQUIFY(prefix) CONCAT(prefix, __LINE__) > + > +#define BUILD_BUG_INTERNAL2(condition, msg, fn) \ > + do { \ > + extern void fn (void) __compiletime_error(msg); \ > + __compiletime_error_fallback(condition); \ > + if (condition) \ > + fn(); \ > + } while (0) > + > +#define BUILD_BUG_INTERNAL(condition, msg, fn) \ > + BUILD_BUG_INTERNAL2(condition, msg, fn) Ditto. BUILD_BUG_INTERNAL2 should be __BUILD_BUG_INTERNAL and the one calling it _BUILD_BUG_INTERNAL (with one underscore). > + > +/** > + * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied > + * error message. > + * @condition: the condition which the compiler should know is false. > + * > + * See BUILD_BUG_ON for description. > + */ > +#define BUILD_BUG_ON_MSG(cond, msg) \ > + BUILD_BUG_INTERNAL(cond, msg, UNIQUIFY(__build_bug_on_failed_)) Btw, why are we adding the line at all? It is issued by gcc anyway: cc -Wall macros.c -o macros macros.c: In function ‘main’: macros.c:22:1: error: ‘__build_bug_on_failed_22’ undeclared (first use in this function) ^^^^ It is in front of the filename here. macros.c:22:1: note: each undeclared identifier is reported only once for each function it appears in make: *** [macros] Error 1 Thanks. -- Regards/Gruss, Boris. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/