1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 2000 Jonathan M. Bresler 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $FreeBSD: src/share/man/man9/KASSERT.9,v 1.1.2.4 2001/07/21 09:16:54 schweikh Exp $ 30.\" $DragonFly: src/share/man/man9/KASSERT.9,v 1.2 2003/06/17 04:37:01 dillon Exp $ 31.\" 32.Dd January 14, 2000 33.Os 34.Dt KASSERT 9 35.Sh NAME 36.Nm KASSERT 37.Nd kernel expression verification macro 38.Sh SYNOPSIS 39.Cd options INVARIANTS 40.Fn KASSERT expression "const char *msg" 41.Sh DESCRIPTION 42In a kernel compiled with "options INVARIANTS", 43the 44.Fn KASSERT 45macro tests the given 46.Ar expression 47and if it is false, 48calls the 49.Fn panic 50syscall, terminating the running system. 51.Pp 52In a kernel that does not have "options INVARIANTS", 53the 54.Fn KASSERT 55macro is defined to be a no-op. 56.Sh EXAMPLES 57The kernel function 58.Fn vput 59must not be called with a NULL pointer. 60.Bd -literal -offset indent 61void 62vput(vp) 63 struct vnode *vp; 64{ 65 struct proc *p = curproc; 66 KASSERT(vp != NULL, ("vput: null vp")); 67 ... 68} 69.Ed 70.Sh SEE ALSO 71.Xr config 8 , 72.Xr panic 9 73.Sh AUTHORS 74This manual page was written by 75.An Jonathan M. Bresler 76.Aq jmb@FreeBSD.org . 77