kconfig.h 3.8 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) _config_enabled(cfg)
  18. #define _config_enabled(value) __config_enabled(__ARG_PLACEHOLDER_##value)
  19. #define __config_enabled(arg1_or_junk) ___config_enabled(arg1_or_junk 1, 0)
  20. #define ___config_enabled(__ignored, val, ...) val
  21. /*
  22. * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y',
  23. * 0 otherwise.
  24. *
  25. */
  26. #define IS_ENABLED(option) \
  27. (config_enabled(option))
  28. /*
  29. * U-Boot add-on: Helper macros to reference to different macros
  30. * (CONFIG_ or CONFIG_SPL_ prefixed), depending on the build context.
  31. */
  32. #if defined(CONFIG_TPL_BUILD)
  33. #define _CONFIG_PREFIX TPL_
  34. #elif defined(CONFIG_SPL_BUILD)
  35. #define _CONFIG_PREFIX SPL_
  36. #else
  37. #define _CONFIG_PREFIX
  38. #endif
  39. #define config_val(cfg) _config_val(_CONFIG_PREFIX, cfg)
  40. #define _config_val(pfx, cfg) __config_val(pfx, cfg)
  41. #define __config_val(pfx, cfg) CONFIG_ ## pfx ## cfg
  42. /*
  43. * CONFIG_VAL(FOO) evaluates to the value of
  44. * CONFIG_FOO if CONFIG_SPL_BUILD is undefined,
  45. * CONFIG_SPL_FOO if CONFIG_SPL_BUILD is defined.
  46. * CONFIG_TPL_FOO if CONFIG_TPL_BUILD is defined.
  47. */
  48. #define CONFIG_VAL(option) config_val(option)
  49. /*
  50. * Count number of arguments to a variadic macro. Currently only need
  51. * it for 1, 2 or 3 arguments.
  52. */
  53. #define __arg6(a1, a2, a3, a4, a5, a6, ...) a6
  54. #define __count_args(...) __arg6(dummy, ##__VA_ARGS__, 4, 3, 2, 1, 0)
  55. #define __concat(a, b) ___concat(a, b)
  56. #define ___concat(a, b) a ## b
  57. #define __unwrap(...) __VA_ARGS__
  58. #define __unwrap1(case1, case0) __unwrap case1
  59. #define __unwrap0(case1, case0) __unwrap case0
  60. #define __CONFIG_IS_ENABLED_1(option) __CONFIG_IS_ENABLED_3(option, (1), (0))
  61. #define __CONFIG_IS_ENABLED_2(option, case1) __CONFIG_IS_ENABLED_3(option, case1, ())
  62. #define __CONFIG_IS_ENABLED_3(option, case1, case0) \
  63. __concat(__unwrap, config_enabled(CONFIG_VAL(option))) (case1, case0)
  64. /*
  65. * CONFIG_IS_ENABLED(FOO) expands to
  66. * 1 if CONFIG_SPL_BUILD is undefined and CONFIG_FOO is set to 'y',
  67. * 1 if CONFIG_SPL_BUILD is defined and CONFIG_SPL_FOO is set to 'y',
  68. * 1 if CONFIG_TPL_BUILD is defined and CONFIG_TPL_FOO is set to 'y',
  69. * 0 otherwise.
  70. *
  71. * CONFIG_IS_ENABLED(FOO, (abc)) expands to
  72. * abc if CONFIG_SPL_BUILD is undefined and CONFIG_FOO is set to 'y',
  73. * abc if CONFIG_SPL_BUILD is defined and CONFIG_SPL_FOO is set to 'y',
  74. * abc if CONFIG_TPL_BUILD is defined and CONFIG_TPL_FOO is set to 'y',
  75. * nothing otherwise.
  76. *
  77. * CONFIG_IS_ENABLED(FOO, (abc), (def)) expands to
  78. * abc if CONFIG_SPL_BUILD is undefined and CONFIG_FOO is set to 'y',
  79. * abc if CONFIG_SPL_BUILD is defined and CONFIG_SPL_FOO is set to 'y',
  80. * abc if CONFIG_TPL_BUILD is defined and CONFIG_TPL_FOO is set to 'y',
  81. * def otherwise.
  82. *
  83. * The optional second and third arguments must be parenthesized; that
  84. * allows one to include a trailing comma, e.g. for use in
  85. *
  86. * CONFIG_IS_ENABLED(ACME, ({.compatible = "acme,frobnozzle"},))
  87. *
  88. * which adds an entry to the array being defined if CONFIG_ACME (or
  89. * CONFIG_SPL_ACME/CONFIG_TPL_ACME, depending on build context) is
  90. * set, and nothing otherwise.
  91. */
  92. #define CONFIG_IS_ENABLED(option, ...) \
  93. __concat(__CONFIG_IS_ENABLED_, __count_args(option, ##__VA_ARGS__)) (option, ##__VA_ARGS__)
  94. #endif /* __LINUX_KCONFIG_H */