14b0552d5SJean-Sébastien Pédron /*- 24b0552d5SJean-Sébastien Pédron * SPDX-License-Identifier: BSD-2-Clause 34b0552d5SJean-Sébastien Pédron * 44b0552d5SJean-Sébastien Pédron * Copyright (c) 2020 The FreeBSD Foundation 54b0552d5SJean-Sébastien Pédron * 64b0552d5SJean-Sébastien Pédron * This software was developed by Björn Zeeb under sponsorship from 74b0552d5SJean-Sébastien Pédron * the FreeBSD Foundation. 84b0552d5SJean-Sébastien Pédron * 94b0552d5SJean-Sébastien Pédron * Redistribution and use in source and binary forms, with or without 104b0552d5SJean-Sébastien Pédron * modification, are permitted provided that the following conditions 114b0552d5SJean-Sébastien Pédron * are met: 124b0552d5SJean-Sébastien Pédron * 1. Redistributions of source code must retain the above copyright 134b0552d5SJean-Sébastien Pédron * notice, this list of conditions and the following disclaimer. 144b0552d5SJean-Sébastien Pédron * 2. Redistributions in binary form must reproduce the above copyright 154b0552d5SJean-Sébastien Pédron * notice, this list of conditions and the following disclaimer in the 164b0552d5SJean-Sébastien Pédron * documentation and/or other materials provided with the distribution. 174b0552d5SJean-Sébastien Pédron * 184b0552d5SJean-Sébastien Pédron * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 194b0552d5SJean-Sébastien Pédron * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 204b0552d5SJean-Sébastien Pédron * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 214b0552d5SJean-Sébastien Pédron * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 224b0552d5SJean-Sébastien Pédron * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 234b0552d5SJean-Sébastien Pédron * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 244b0552d5SJean-Sébastien Pédron * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 254b0552d5SJean-Sébastien Pédron * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 264b0552d5SJean-Sébastien Pédron * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 274b0552d5SJean-Sébastien Pédron * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 284b0552d5SJean-Sébastien Pédron * SUCH DAMAGE. 294b0552d5SJean-Sébastien Pédron */ 304b0552d5SJean-Sébastien Pédron 314b0552d5SJean-Sébastien Pédron #ifndef _LINUXKPI_LINUX_KCONFIG_H_ 324b0552d5SJean-Sébastien Pédron #define _LINUXKPI_LINUX_KCONFIG_H_ 334b0552d5SJean-Sébastien Pédron 344b0552d5SJean-Sébastien Pédron /* 354b0552d5SJean-Sébastien Pédron * Checking if an option is defined would be easy if we could do CPP inside CPP. 364b0552d5SJean-Sébastien Pédron * The defined case whether -Dxxx or -Dxxx=1 are easy to deal with. In either 374b0552d5SJean-Sébastien Pédron * case the defined value is "1". A more general -Dxxx=<c> case will require 384b0552d5SJean-Sébastien Pédron * more effort to deal with all possible "true" values. Hope we do not have 394b0552d5SJean-Sébastien Pédron * to do this as well. 404b0552d5SJean-Sébastien Pédron * The real problem is the undefined case. To avoid this problem we do the 414b0552d5SJean-Sébastien Pédron * concat/varargs trick: "yyy" ## xxx can make two arguments if xxx is "1" 424b0552d5SJean-Sébastien Pédron * by having a #define for yyy_1 which is "ignore,". 434b0552d5SJean-Sébastien Pédron * Otherwise we will just get "yyy". 444b0552d5SJean-Sébastien Pédron * Need to be careful about variable substitutions in macros though. 454b0552d5SJean-Sébastien Pédron * This way we make a (true, false) problem a (don't care, true, false) or a 464b0552d5SJean-Sébastien Pédron * (don't care true, false). Then we can use a variadic macro to only select 474b0552d5SJean-Sébastien Pédron * the always well known and defined argument #2. And that seems to be 484b0552d5SJean-Sébastien Pédron * exactly what we need. Use 1 for true and 0 for false to also allow 494b0552d5SJean-Sébastien Pédron * #if IS_*() checks pre-compiler checks which do not like #if true. 504b0552d5SJean-Sébastien Pédron */ 514b0552d5SJean-Sébastien Pédron #define ___XAB_1 dontcare, 524b0552d5SJean-Sébastien Pédron #define ___IS_XAB(_ignore, _x, ...) (_x) 534b0552d5SJean-Sébastien Pédron #define __IS_XAB(_x) ___IS_XAB(_x 1, 0) 544b0552d5SJean-Sébastien Pédron #define _IS_XAB(_x) __IS_XAB(__CONCAT(___XAB_, _x)) 554b0552d5SJean-Sébastien Pédron 564b0552d5SJean-Sébastien Pédron /* This is if CONFIG_ccc=y. */ 574b0552d5SJean-Sébastien Pédron #define IS_BUILTIN(_x) _IS_XAB(_x) 584b0552d5SJean-Sébastien Pédron /* This is if CONFIG_ccc=m. */ 594b0552d5SJean-Sébastien Pédron #define IS_MODULE(_x) _IS_XAB(_x ## _MODULE) 604b0552d5SJean-Sébastien Pédron /* This is if CONFIG_ccc is compiled in(=y) or a module(=m). */ 614b0552d5SJean-Sébastien Pédron #define IS_ENABLED(_x) (IS_BUILTIN(_x) || IS_MODULE(_x)) 624b0552d5SJean-Sébastien Pédron /* 634b0552d5SJean-Sébastien Pédron * This is weird case. If the CONFIG_ccc is builtin (=y) this returns true; 644b0552d5SJean-Sébastien Pédron * or if the CONFIG_ccc is a module (=m) and the caller is built as a module 654b0552d5SJean-Sébastien Pédron * (-DMODULE defined) this returns true, but if the callers is not a module 664b0552d5SJean-Sébastien Pédron * (-DMODULE not defined, which means caller is BUILTIN) then it returns 674b0552d5SJean-Sébastien Pédron * false. In other words, a module can reach the kernel, a module can reach 684b0552d5SJean-Sébastien Pédron * a module, but the kernel cannot reach a module, and code never compiled 694b0552d5SJean-Sébastien Pédron * cannot be reached either. 704b0552d5SJean-Sébastien Pédron * XXX -- I'd hope the module-to-module case would be handled by a proper 714b0552d5SJean-Sébastien Pédron * module dependency definition (MODULE_DEPEND() in FreeBSD). 724b0552d5SJean-Sébastien Pédron */ 734b0552d5SJean-Sébastien Pédron #define IS_REACHABLE(_x) (IS_BUILTIN(_x) || \ 744b0552d5SJean-Sébastien Pédron (IS_MODULE(_x) && IS_BUILTIN(MODULE))) 754b0552d5SJean-Sébastien Pédron 764b0552d5SJean-Sébastien Pédron #endif /* _LINUXKPI_LINUX_KCONFIG_H_ */ 77