1.\" Copyright (c) 2021 The FreeBSD Foundation 2.\" 3.\" This document was written by Ed Maste under sponsorship from 4.\" The FreeBSD Foundation. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.Dd June 24, 2025 27.Dt GONE_IN 9 28.Os 29.Sh NAME 30.Nm gone_in , 31.Nm gone_in_dev 32.Nd deprecation notice functions 33.Sh SYNOPSIS 34.In sys/systm.h 35.Ft void 36.Fn gone_in "int major" "const char *msg" "..." 37.Ft void 38.Fn gone_in_dev "device_t dev" "int major" "const char *msg" "..." 39.Sh DESCRIPTION 40The 41.Nm gone_in 42functions are used to provide a notice that the kernel is actively using a 43driver or some other functionality that is deprecated, and is planned for 44removal in a future 45.Fx 46release. 47The notice is sent to the kernel 48.Xr dmesg 8 49log and will appear on the console. 50The 51.Fa major 52argument specifies the major version of the 53.Fx 54release that will remove the deprecated functionality. 55The notice shall be printed only once, thus 56.Nm 57functions are safe to use in often executed code paths. 58.Pp 59.Nm gone_in_dev 60will prepend driver name before the notice. 61.Pp 62In releases before 63.Fa major 64the provided notice will be appended with 65.Do 66To be removed in FreeBSD 67.Fa major Ns 68.Dc . 69.Sh EXAMPLES 70.Bd -literal -offset indent 71void 72example_api(foo_t *args) 73{ 74 gone_in(16, "Warning! %s[%u] uses obsolete API. ", 75 curthread->td_proc->p_comm, curthread->td_proc->p_pid); 76 77 /* API implementation omitted. */ 78} 79 80int 81example_driver_attach(struct example_driver_softc *sc) 82{ 83 /* Attach code omitted. */ 84 85 gone_in_dev(sc->dev, 16, "driver is deprecated"); 86} 87.Ed 88.Sh HISTORY 89The 90.Nm 91functions first appeared in 92.Fx 11 . 93