While I happen to know these warnings are false alerts, dmsetup.c:1949: warning: cast from pointer to integer of different size dmsetup.c:1950: warning: cast from pointer to integer of different size dmsetup.c:1951: warning: cast from pointer to integer of different size dmsetup.c:1952: warning: cast from pointer to integer of different size dmsetup.c:1953: warning: cast from pointer to integer of different size dmsetup.c:1955: warning: cast from pointer to integer of different size their mere presence (and our becoming inured to them) makes it more likely someone will introduce a new one that will be ignored along with all those. So I changed the offending OFFSET_OF macro to generate equivalent code (-O2-generated, before/after .o files are identical) but without triggering the warning: >From 1219430622d29c7a3f8bdc6ad1fdd2a64082070e Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyering@xxxxxxxxxx> Date: Wed, 18 Jun 2008 12:05:12 +0200 Subject: [PATCH] avoid compiler warning about cast in OFFSET_OF macro * dmsetup/dmsetup.c (OFFSET_OF): Use an equivalent definition that does not cast a pointer value to a narrower type. --- dmsetup/dmsetup.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/dmsetup/dmsetup.c b/dmsetup/dmsetup.c index fdc52e3..b242f1c 100644 --- a/dmsetup/dmsetup.c +++ b/dmsetup/dmsetup.c @@ -1,6 +1,6 @@ /* * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved. - * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. + * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. * Copyright (C) 2005-2007 NEC Corporation * * This file is part of the device-mapper userspace tools. @@ -1927,7 +1927,7 @@ static const struct dm_report_object_type _report_types[] = { }; /* Column definitions */ -#define OFFSET_OF(strct, field) ((unsigned int) &((struct strct *)NULL)->field) +#define OFFSET_OF(strct, field) (((char*)&((struct strct*)0)->field) - (char*)0) #define STR (DM_REPORT_FIELD_TYPE_STRING) #define NUM (DM_REPORT_FIELD_TYPE_NUMBER) #define FIELD_O(type, strct, sorttype, head, field, width, func, id, desc) {DR_ ## type, sorttype, OFFSET_OF(strct, field), width, id, head, &_ ## func ## _disp, desc}, -- 1.5.6.rc3.13.gb55d4 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel