1 /* $NetBSD: offset.h,v 1.4 2014/12/10 04:38:01 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004, 2007 Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (C) 2000, 2001 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* Id: offset.h,v 1.6 2007/06/19 23:47:20 tbox Exp */ 21 22 #ifndef ISC_OFFSET_H 23 #define ISC_OFFSET_H 1 24 25 /* 26 * File offsets are operating-system dependent. 27 */ 28 #include <limits.h> /* Required for CHAR_BIT. */ 29 #include <sys/types.h> 30 31 typedef _off_t isc_offset_t; 32 33 /* 34 * POSIX says "Additionally, blkcnt_t and off_t are extended signed integral 35 * types", so the maximum value is all 1s except for the high bit. 36 * This definition is more complex than it really needs to be because it was 37 * crafted to keep both the SunOS 5.6 and the HP/UX 11 compilers quiet about 38 * integer overflow. For example, though this is equivalent to just left 39 * shifting 1 to the high bit and then inverting the bits, the SunOS compiler 40 * is unhappy about shifting a positive "1" to negative in a signed integer. 41 */ 42 #define ISC_OFFSET_MAXIMUM \ 43 (~(((off_t)-1 >> (sizeof(off_t) * CHAR_BIT - 1)) \ 44 << (sizeof(off_t) * CHAR_BIT - 1))) 45 46 #endif /* ISC_OFFSET_H */ 47