kconfig.h 1.9 KB

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  1. #ifndef __LINUX_KCONFIG_H
  2. #define __LINUX_KCONFIG_H
  3. #include <generated/autoconf.h>
  4. /*
  5. * Helper macros to use CONFIG_ options in C/CPP expressions. Note that
  6. * these only work with boolean and tristate options.
  7. */
  8. /*
  9. * Getting something that works in C and CPP for an arg that may or may
  10. * not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1"
  11. * we match on the placeholder define, insert the "0," for arg1 and generate
  12. * the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one).
  13. * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
  14. * the last step cherry picks the 2nd arg, we get a zero.
  15. */
  16. #define __ARG_PLACEHOLDER_1 0,
  17. #define config_enabled(cfg) ___is_defined(cfg)
  18. #define __is_defined(x) ___is_defined(x)
  19. #define ___is_defined(val) ____is_defined(__ARG_PLACEHOLDER_##val)
  20. #define ____is_defined(arg1_or_junk) __take_second_arg(arg1_or_junk 1, 0)
  21. #define __take_second_arg(__ignored, val, ...) val
  22. /*
  23. * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
  24. * otherwise. For boolean options, this is equivalent to
  25. * IS_ENABLED(CONFIG_FOO).
  26. */
  27. #define IS_BUILTIN(option) config_enabled(option)
  28. /*
  29. * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0
  30. * otherwise.
  31. */
  32. #define IS_MODULE(option) config_enabled(option##_MODULE)
  33. /*
  34. * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
  35. * code can call a function defined in code compiled based on CONFIG_FOO.
  36. * This is similar to IS_ENABLED(), but returns false when invoked from
  37. * built-in code when CONFIG_FOO is set to 'm'.
  38. */
  39. #define IS_REACHABLE(option) (config_enabled(option) || \
  40. (config_enabled(option##_MODULE) && __is_defined(MODULE)))
  41. /*
  42. * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',
  43. * 0 otherwise.
  44. */
  45. #define IS_ENABLED(option) \
  46. (IS_BUILTIN(option) || IS_MODULE(option))
  47. #endif /* __LINUX_KCONFIG_H */