1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _TOOLS_LINUX_KCONFIG_H 3 #define _TOOLS_LINUX_KCONFIG_H 4 5 /* CONFIG_CC_VERSION_TEXT (Do not delete this comment. See help in Kconfig) */ 6 7 #define __ARG_PLACEHOLDER_1 0, 8 #define __take_second_arg(__ignored, val, ...) val 9 10 /* 11 * The use of "&&" / "||" is limited in certain expressions. 12 * The following enable to calculate "and" / "or" with macro expansion only. 13 */ 14 #define __and(x, y) ___and(x, y) 15 #define ___and(x, y) ____and(__ARG_PLACEHOLDER_##x, y) 16 #define ____and(arg1_or_junk, y) __take_second_arg(arg1_or_junk y, 0) 17 18 #define __or(x, y) ___or(x, y) 19 #define ___or(x, y) ____or(__ARG_PLACEHOLDER_##x, y) 20 #define ____or(arg1_or_junk, y) __take_second_arg(arg1_or_junk 1, y) 21 22 /* 23 * Helper macros to use CONFIG_ options in C/CPP expressions. Note that 24 * these only work with boolean and tristate options. 25 */ 26 27 /* 28 * Getting something that works in C and CPP for an arg that may or may 29 * not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1" 30 * we match on the placeholder define, insert the "0," for arg1 and generate 31 * the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one). 32 * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when 33 * the last step cherry picks the 2nd arg, we get a zero. 34 */ 35 #define __is_defined(x) ___is_defined(x) 36 #define ___is_defined(val) ____is_defined(__ARG_PLACEHOLDER_##val) 37 #define ____is_defined(arg1_or_junk) __take_second_arg(arg1_or_junk 1, 0) 38 39 /* 40 * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0 41 * otherwise. For boolean options, this is equivalent to 42 * IS_ENABLED(CONFIG_FOO). 43 */ 44 #define IS_BUILTIN(option) __is_defined(option) 45 46 /* 47 * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0 48 * otherwise. 49 */ 50 #define IS_MODULE(option) __is_defined(option##_MODULE) 51 52 /* 53 * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled 54 * code can call a function defined in code compiled based on CONFIG_FOO. 55 * This is similar to IS_ENABLED(), but returns false when invoked from 56 * built-in code when CONFIG_FOO is set to 'm'. 57 */ 58 #define IS_REACHABLE(option) __or(IS_BUILTIN(option), \ 59 __and(IS_MODULE(option), __is_defined(MODULE))) 60 61 /* 62 * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm', 63 * 0 otherwise. 64 */ 65 #define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option)) 66 67 #endif /* _TOOLS_LINUX_KCONFIG_H */ 68