1 #ifndef __LINUX_KCONFIG_H
2 #define __LINUX_KCONFIG_H
4 #include <generated/autoconf.h>
7 * Helper macros to use CONFIG_ options in C/CPP expressions. Note that
8 * these only work with boolean and tristate options.
12 * Getting something that works in C and CPP for an arg that may or may
13 * not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1"
14 * we match on the placeholder define, insert the "0," for arg1 and generate
15 * the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one).
16 * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
17 * the last step cherry picks the 2nd arg, we get a zero.
19 #define __ARG_PLACEHOLDER_1 0,
20 #define config_enabled(cfg) ___is_defined(cfg)
21 #define __is_defined(x) ___is_defined(x)
22 #define ___is_defined(val) ____is_defined(__ARG_PLACEHOLDER_##val)
23 #define ____is_defined(arg1_or_junk) __take_second_arg(arg1_or_junk 1, 0)
24 #define __take_second_arg(__ignored, val, ...) val
27 * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
28 * otherwise. For boolean options, this is equivalent to
29 * IS_ENABLED(CONFIG_FOO).
31 #define IS_BUILTIN(option) config_enabled(option)
34 * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0
37 #define IS_MODULE(option) config_enabled(option##_MODULE)
40 * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
41 * code can call a function defined in code compiled based on CONFIG_FOO.
42 * This is similar to IS_ENABLED(), but returns false when invoked from
43 * built-in code when CONFIG_FOO is set to 'm'.
45 #define IS_REACHABLE(option) (config_enabled(option) || \
46 (config_enabled(option##_MODULE) && __is_defined(MODULE)))
49 * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',
52 #define IS_ENABLED(option) \
53 (IS_BUILTIN(option) || IS_MODULE(option))
55 #endif /* __LINUX_KCONFIG_H */