1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _TOOLS_LINUX_KCONFIG_H
3#define _TOOLS_LINUX_KCONFIG_H
4
5/* CONFIG_CC_VERSION_TEXT (Do not delete this comment. See help in Kconfig) */
6
7#define __ARG_PLACEHOLDER_1 0,
8#define __take_second_arg(__ignored, val, ...) val
9
10/*
11 * The use of "&&" / "||" is limited in certain expressions.
12 * The following enable to calculate "and" / "or" with macro expansion only.
13 */
14#define __and(x, y)			___and(x, y)
15#define ___and(x, y)			____and(__ARG_PLACEHOLDER_##x, y)
16#define ____and(arg1_or_junk, y)	__take_second_arg(arg1_or_junk y, 0)
17
18#define __or(x, y)			___or(x, y)
19#define ___or(x, y)			____or(__ARG_PLACEHOLDER_##x, y)
20#define ____or(arg1_or_junk, y)		__take_second_arg(arg1_or_junk 1, y)
21
22/*
23 * Helper macros to use CONFIG_ options in C/CPP expressions. Note that
24 * these only work with boolean and tristate options.
25 */
26
27/*
28 * Getting something that works in C and CPP for an arg that may or may
29 * not be defined is tricky.  Here, if we have "#define CONFIG_BOOGER 1"
30 * we match on the placeholder define, insert the "0," for arg1 and generate
31 * the triplet (0, 1, 0).  Then the last step cherry picks the 2nd arg (a one).
32 * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
33 * the last step cherry picks the 2nd arg, we get a zero.
34 */
35#define __is_defined(x)			___is_defined(x)
36#define ___is_defined(val)		____is_defined(__ARG_PLACEHOLDER_##val)
37#define ____is_defined(arg1_or_junk)	__take_second_arg(arg1_or_junk 1, 0)
38
39/*
40 * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
41 * otherwise. For boolean options, this is equivalent to
42 * IS_ENABLED(CONFIG_FOO).
43 */
44#define IS_BUILTIN(option) __is_defined(option)
45
46/*
47 * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0
48 * otherwise.
49 */
50#define IS_MODULE(option) __is_defined(option##_MODULE)
51
52/*
53 * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
54 * code can call a function defined in code compiled based on CONFIG_FOO.
55 * This is similar to IS_ENABLED(), but returns false when invoked from
56 * built-in code when CONFIG_FOO is set to 'm'.
57 */
58#define IS_REACHABLE(option) __or(IS_BUILTIN(option), \
59				__and(IS_MODULE(option), __is_defined(MODULE)))
60
61/*
62 * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',
63 * 0 otherwise.
64 */
65#define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option))
66
67#endif /* _TOOLS_LINUX_KCONFIG_H */
68