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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 */ |