diff options
Diffstat (limited to 'include/linux/kconfig.h')
| -rw-r--r-- | include/linux/kconfig.h | 61 |
1 files changed, 45 insertions, 16 deletions
diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h index be342b94c640..20d1079e92b4 100644 --- a/include/linux/kconfig.h +++ b/include/linux/kconfig.h @@ -1,8 +1,30 @@ +/* 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. @@ -16,31 +38,38 @@ * 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 __ARG_PLACEHOLDER_1 0, -#define config_enabled(cfg) _config_enabled(cfg) -#define _config_enabled(value) __config_enabled(__ARG_PLACEHOLDER_##value) -#define __config_enabled(arg1_or_junk) ___config_enabled(arg1_or_junk 1, 0) -#define ___config_enabled(__ignored, val, ...) val - -/* - * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm', - * 0 otherwise. - * - */ -#define IS_ENABLED(option) \ - (config_enabled(option) || config_enabled(option##_MODULE)) +#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) config_enabled(option) +#define IS_BUILTIN(option) __is_defined(option) /* * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0 - * otherwise. + * 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_MODULE(option) config_enabled(option##_MODULE) +#define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option)) #endif /* __LINUX_KCONFIG_H */ |