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- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef __LINUX_KCONFIG_H
- #define __LINUX_KCONFIG_H
- #include <generated/autoconf.h>
- #ifdef CONFIG_CPU_BIG_ENDIAN
- #define __BIG_ENDIAN 4321
- #else
- #define __LITTLE_ENDIAN 1234
- #endif
- #define __ARG_PLACEHOLDER_1 0,
- #define __take_second_arg(__ignored, val, ...) val
- /*
- * The use of "&&" / "||" is limited in certain expressions.
- * The following enable to calculate "and" / "or" with macro expansion only.
- */
- #define __and(x, y) ___and(x, y)
- #define ___and(x, y) ____and(__ARG_PLACEHOLDER_##x, y)
- #define ____and(arg1_or_junk, y) __take_second_arg(arg1_or_junk y, 0)
- #define __or(x, y) ___or(x, y)
- #define ___or(x, y) ____or(__ARG_PLACEHOLDER_##x, y)
- #define ____or(arg1_or_junk, y) __take_second_arg(arg1_or_junk 1, y)
- /*
- * Helper macros to use CONFIG_ options in C/CPP expressions. Note that
- * these only work with boolean and tristate options.
- */
- /*
- * Getting something that works in C and CPP for an arg that may or may
- * not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1"
- * we match on the placeholder define, insert the "0," for arg1 and generate
- * the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one).
- * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
- * the last step cherry picks the 2nd arg, we get a zero.
- */
- #define __is_defined(x) ___is_defined(x)
- #define ___is_defined(val) ____is_defined(__ARG_PLACEHOLDER_##val)
- #define ____is_defined(arg1_or_junk) __take_second_arg(arg1_or_junk 1, 0)
- /*
- * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
- * otherwise. For boolean options, this is equivalent to
- * IS_ENABLED(CONFIG_FOO).
- */
- #define IS_BUILTIN(option) __is_defined(option)
- /*
- * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0
- * otherwise. CONFIG_FOO=m results in "#define CONFIG_FOO_MODULE 1" in
- * autoconf.h.
- */
- #define IS_MODULE(option) __is_defined(option##_MODULE)
- /*
- * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
- * code can call a function defined in code compiled based on CONFIG_FOO.
- * This is similar to IS_ENABLED(), but returns false when invoked from
- * built-in code when CONFIG_FOO is set to 'm'.
- */
- #define IS_REACHABLE(option) __or(IS_BUILTIN(option), \
- __and(IS_MODULE(option), __is_defined(MODULE)))
- /*
- * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',
- * 0 otherwise. Note that CONFIG_FOO=y results in "#define CONFIG_FOO 1" in
- * autoconf.h, while CONFIG_FOO=m results in "#define CONFIG_FOO_MODULE 1".
- */
- #define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option))
- #endif /* __LINUX_KCONFIG_H */
|
