xref: /linux/tools/include/tools/config.h (revision 0be3ff0c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _TOOLS_CONFIG_H
3 #define _TOOLS_CONFIG_H
4 
5 /* Subset of include/linux/kconfig.h */
6 
7 #define __ARG_PLACEHOLDER_1 0,
8 #define __take_second_arg(__ignored, val, ...) val
9 
10 /*
11  * Helper macros to use CONFIG_ options in C/CPP expressions. Note that
12  * these only work with boolean and tristate options.
13  */
14 
15 /*
16  * Getting something that works in C and CPP for an arg that may or may
17  * not be defined is tricky.  Here, if we have "#define CONFIG_BOOGER 1"
18  * we match on the placeholder define, insert the "0," for arg1 and generate
19  * the triplet (0, 1, 0).  Then the last step cherry picks the 2nd arg (a one).
20  * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
21  * the last step cherry picks the 2nd arg, we get a zero.
22  */
23 #define __is_defined(x)			___is_defined(x)
24 #define ___is_defined(val)		____is_defined(__ARG_PLACEHOLDER_##val)
25 #define ____is_defined(arg1_or_junk)	__take_second_arg(arg1_or_junk 1, 0)
26 
27 /*
28  * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
29  * otherwise. For boolean options, this is equivalent to
30  * IS_ENABLED(CONFIG_FOO).
31  */
32 #define IS_BUILTIN(option) __is_defined(option)
33 
34 #endif /* _TOOLS_CONFIG_H */
35