diff options
Diffstat (limited to 'include/c.h')
| -rw-r--r-- | include/c.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/include/c.h b/include/c.h index dcb2d683c7..e0148e019c 100644 --- a/include/c.h +++ b/include/c.h @@ -82,6 +82,39 @@ # endif #endif +#ifdef __has_attribute +# define UL_HAS_ATTRIBUTE(x) __has_attribute(x) +#else +# define UL_HAS_ATTRIBUTE(x) 0 +#endif + +/* C-language Attributes are added in C23. */ +#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute) +# define UL_HAS_C_ATTRIBUTE(x) __has_c_attribute(x) +#else +# define UL_HAS_C_ATTRIBUTE(x) 0 +#endif + +#if defined(__cplusplus) && defined(__has_cpp_attribute) +# define UL_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) +#else +# define UL_HAS_CPP_ATTRIBUTE(x) 0 +#endif + +/* +Define FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute +introduced in CPP17 and C23. +CPP17 : https://en.cppreference.com/w/cpp/language/attributes/fallthrough +C23 : https://en.cppreference.com/w/c/language/attributes/fallthrough +*/ +#if UL_HAS_C_ATTRIBUTE(fallthrough) || UL_HAS_CPP_ATTRIBUTE(fallthrough) +# define FALLTHROUGH [[fallthrough]] +#elif UL_HAS_ATTRIBUTE(__fallthrough__) +# define FALLTHROUGH __attribute__ ((__fallthrough__)) +#else +# define FALLTHROUGH /* fallthrough */ +#endif + /* * It evaluates to 1 if the attribute/feature is supported by the current |