From owner-freebsd-standards@FreeBSD.ORG Wed Dec 31 16:50:16 2003 Return-Path: Delivered-To: freebsd-standards@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9749816A4CE for ; Wed, 31 Dec 2003 16:50:16 -0800 (PST) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6169A43D1F for ; Wed, 31 Dec 2003 16:50:14 -0800 (PST) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) i010oEFR028844 for ; Wed, 31 Dec 2003 16:50:14 -0800 (PST) (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.10/8.12.10/Submit) id i010oE0D028843; Wed, 31 Dec 2003 16:50:14 -0800 (PST) (envelope-from gnats) Resent-Date: Wed, 31 Dec 2003 16:50:14 -0800 (PST) Resent-Message-Id: <200401010050.i010oE0D028843@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-standards@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Jason Evans Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3A79316A4CE for ; Wed, 31 Dec 2003 16:40:31 -0800 (PST) Received: from canonware.com (dslh174.fsr.net [12.32.33.174]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4573843D1D for ; Wed, 31 Dec 2003 16:40:30 -0800 (PST) (envelope-from jasone@canonware.com) Received: by canonware.com (Postfix, from userid 1001) id 19C541C5; Wed, 31 Dec 2003 16:40:57 -0800 (PST) Message-Id: <20040101004057.19C541C5@canonware.com> Date: Wed, 31 Dec 2003 16:40:57 -0800 (PST) From: Jason Evans To: FreeBSD-gnats-submit@FreeBSD.org X-Send-Pr-Version: 3.113 Subject: standards/60772: _Bool and bool should be unsigned X-BeenThere: freebsd-standards@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: Jason Evans List-Id: Standards compliance List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Jan 2004 00:50:16 -0000 >Number: 60772 >Category: standards >Synopsis: _Bool and bool should be unsigned >Confidential: no >Severity: serious >Priority: high >Responsible: freebsd-standards >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Dec 31 16:50:14 PST 2003 >Closed-Date: >Last-Modified: >Originator: Jason Evans >Release: FreeBSD 4.9-RC i386 >Organization: >Environment: System: FreeBSD canonware.com 4.9-RC FreeBSD 4.9-RC #12: Fri Oct 17 22:15:36 PDT 2003 jasone@canonware.com:/usr/src/sys/compile/CANONWARE i386 >Description: _Bool and bool must be unsigned, so that structure bit fields work as expected. >How-To-Repeat: #include #include /* _Bool and bool must be unsigned. Otherwise, stucture bit fields do not work * correctly, due to how sign extension works. */ struct foo { bool white:1; /* Note :1 (bit field). */ }; struct bar { bool white:2; }; int main(void) { struct foo foo; struct bar bar; bool white; foo.white = false; fprintf(stderr, "%u (expect 0)\n", foo.white); fprintf(stderr, "%u (expect 1)\n", !foo.white); foo.white = !foo.white; /* Breaks. */ fprintf(stderr, "%u (expect 1)\n", foo.white); fprintf(stderr, "%u (expect 0)\n", !foo.white); bar.white = false; fprintf(stderr, "%u (expect 0)\n", bar.white); fprintf(stderr, "%u (expect 1)\n", !bar.white); bar.white = !bar.white; fprintf(stderr, "%u (expect 1)\n", bar.white); fprintf(stderr, "%u (expect 0)\n", !bar.white); white = false; fprintf(stderr, "%u (expect 0)\n", white); fprintf(stderr, "%u (expect 1)\n", !white); white = !white; fprintf(stderr, "%u (expect 1)\n", white); fprintf(stderr, "%u (expect 0)\n", !white); return 0; } >Fix: Using bit fields with more than one bit works around the problem, but is not a satisfactory workaround. This bug can cause obscure problems, since something like: if (foo.white == true) ...; breaks. >Release-Note: >Audit-Trail: >Unformatted: