| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef __LINUX_KCONFIG_H |
| 3 | #define __LINUX_KCONFIG_H |
| 4 | |
| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 5 | /* CONFIG_CC_VERSION_TEXT (Do not delete this comment. See help in Kconfig) */ |
| 6 | |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 7 | #include <generated/autoconf.h> |
| 8 | |
| 9 | #ifdef CONFIG_CPU_BIG_ENDIAN |
| 10 | #define __BIG_ENDIAN 4321 |
| 11 | #else |
| 12 | #define __LITTLE_ENDIAN 1234 |
| 13 | #endif |
| 14 | |
| 15 | #define __ARG_PLACEHOLDER_1 0, |
| 16 | #define __take_second_arg(__ignored, val, ...) val |
| 17 | |
| 18 | /* |
| 19 | * The use of "&&" / "||" is limited in certain expressions. |
| 20 | * The following enable to calculate "and" / "or" with macro expansion only. |
| 21 | */ |
| 22 | #define __and(x, y) ___and(x, y) |
| 23 | #define ___and(x, y) ____and(__ARG_PLACEHOLDER_##x, y) |
| 24 | #define ____and(arg1_or_junk, y) __take_second_arg(arg1_or_junk y, 0) |
| 25 | |
| 26 | #define __or(x, y) ___or(x, y) |
| 27 | #define ___or(x, y) ____or(__ARG_PLACEHOLDER_##x, y) |
| 28 | #define ____or(arg1_or_junk, y) __take_second_arg(arg1_or_junk 1, y) |
| 29 | |
| 30 | /* |
| 31 | * Helper macros to use CONFIG_ options in C/CPP expressions. Note that |
| 32 | * these only work with boolean and tristate options. |
| 33 | */ |
| 34 | |
| 35 | /* |
| 36 | * Getting something that works in C and CPP for an arg that may or may |
| 37 | * not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1" |
| 38 | * we match on the placeholder define, insert the "0," for arg1 and generate |
| 39 | * the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one). |
| 40 | * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when |
| 41 | * the last step cherry picks the 2nd arg, we get a zero. |
| 42 | */ |
| 43 | #define __is_defined(x) ___is_defined(x) |
| 44 | #define ___is_defined(val) ____is_defined(__ARG_PLACEHOLDER_##val) |
| 45 | #define ____is_defined(arg1_or_junk) __take_second_arg(arg1_or_junk 1, 0) |
| 46 | |
| 47 | /* |
| 48 | * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0 |
| 49 | * otherwise. For boolean options, this is equivalent to |
| 50 | * IS_ENABLED(CONFIG_FOO). |
| 51 | */ |
| 52 | #define IS_BUILTIN(option) __is_defined(option) |
| 53 | |
| 54 | /* |
| 55 | * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0 |
| 56 | * otherwise. |
| 57 | */ |
| 58 | #define IS_MODULE(option) __is_defined(option##_MODULE) |
| 59 | |
| 60 | /* |
| 61 | * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled |
| 62 | * code can call a function defined in code compiled based on CONFIG_FOO. |
| 63 | * This is similar to IS_ENABLED(), but returns false when invoked from |
| 64 | * built-in code when CONFIG_FOO is set to 'm'. |
| 65 | */ |
| 66 | #define IS_REACHABLE(option) __or(IS_BUILTIN(option), \ |
| 67 | __and(IS_MODULE(option), __is_defined(MODULE))) |
| 68 | |
| 69 | /* |
| 70 | * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm', |
| 71 | * 0 otherwise. |
| 72 | */ |
| 73 | #define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option)) |
| 74 | |
| 75 | #endif /* __LINUX_KCONFIG_H */ |