From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from vpn.id2.novell.com (vpn.id2.novell.com [195.33.99.129]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "emea1-mh.id2.novell.com", Issuer "APPS" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 12620B7C1B for ; Tue, 29 Sep 2009 19:48:50 +1000 (EST) Message-Id: <4AC1E15502000078000516B5@vpn.id2.novell.com> Date: Tue, 29 Sep 2009 10:28:36 +0100 From: "Jan Beulich" To: , Subject: Re: linux-next: tree build failure Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: akpm@linux-foundation.org, linux-next@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >>> Hollis Blanchard 09/29/09 2:00 AM >>> >First, I think there is a real bug here, and the code should read like >this (to match the comment): > /* type has to be known at build time for optimization */ >- BUILD_BUG_ON(__builtin_constant_p(type)); >+ BUILD_BUG_ON(!__builtin_constant_p(type)); > >However, I get the same build error *both* ways, i.e. >__builtin_constant_p(type) evaluates to both 0 and 1? Either that, or >the new BUILD_BUG_ON() macro isn't working... No, at this point of the compilation process it's neither zero nor one, it's simply considered non-constant by the compiler at that stage (this builtin is used for optimization, not during parsing, and the error gets generated when the body of the function gets parsed, not when code gets generated from it). Jan