1 #ifndef __LINUX_KCONFIG_H 2 #define __LINUX_KCONFIG_H 3 4 #include <generated/autoconf.h> 5 6 /* 7 * Helper macros to use CONFIG_ options in C/CPP expressions. Note that 8 * these only work with boolean and tristate options. 9 */ 10 11 /* 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. 18 */ 19 #define __ARG_PLACEHOLDER_1 0, 20 #define config_enabled(cfg) _config_enabled(cfg) 21 #define _config_enabled(value) __config_enabled(__ARG_PLACEHOLDER_##value) 22 #define __config_enabled(arg1_or_junk) ___config_enabled(arg1_or_junk 1, 0) 23 #define ___config_enabled(__ignored, val, ...) val 24 25 /* 26 * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0 27 * otherwise. For boolean options, this is equivalent to 28 * IS_ENABLED(CONFIG_FOO). 29 */ 30 #define IS_BUILTIN(option) config_enabled(option) 31 32 /* 33 * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0 34 * otherwise. 35 */ 36 #define IS_MODULE(option) config_enabled(option##_MODULE) 37 38 /* 39 * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled 40 * code can call a function defined in code compiled based on CONFIG_FOO. 41 * This is similar to IS_ENABLED(), but returns false when invoked from 42 * built-in code when CONFIG_FOO is set to 'm'. 43 */ 44 #define IS_REACHABLE(option) (config_enabled(option) || \ 45 (config_enabled(option##_MODULE) && config_enabled(MODULE))) 46 47 /* 48 * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm', 49 * 0 otherwise. 50 */ 51 #define IS_ENABLED(option) \ 52 (IS_BUILTIN(option) || IS_MODULE(option)) 53 54 #endif /* __LINUX_KCONFIG_H */ 55