diff options
Diffstat (limited to 'include/linux/compiler_types.h')
| -rw-r--r-- | include/linux/compiler_types.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 6fcf73200b67..d4e1956f903f 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -218,6 +218,53 @@ struct ftrace_likely_data { /* Are two types/vars the same type (ignoring qualifiers)? */ #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) +/* + * __unqual_scalar_typeof(x) - Declare an unqualified scalar type, leaving + * non-scalar types unchanged. + */ +#if (defined(CONFIG_CC_IS_GCC) && CONFIG_GCC_VERSION < 40900) || defined(__CHECKER__) +/* + * We build this out of a couple of helper macros in a vain attempt to + * help you keep your lunch down while reading it. + */ +#define __pick_scalar_type(x, type, otherwise) \ + __builtin_choose_expr(__same_type(x, type), (type)0, otherwise) + +/* + * 'char' is not type-compatible with either 'signed char' or 'unsigned char', + * so we include the naked type here as well as the signed/unsigned variants. + */ +#define __pick_integer_type(x, type, otherwise) \ + __pick_scalar_type(x, type, \ + __pick_scalar_type(x, unsigned type, \ + __pick_scalar_type(x, signed type, otherwise))) + +#define __unqual_scalar_typeof(x) typeof( \ + __pick_integer_type(x, char, \ + __pick_integer_type(x, short, \ + __pick_integer_type(x, int, \ + __pick_integer_type(x, long, \ + __pick_integer_type(x, long long, x)))))) +#else +/* + * If supported, prefer C11 _Generic for better compile-times. As above, 'char' + * is not type-compatible with 'signed char', and we define a separate case. + */ +#define __scalar_type_to_expr_cases(type) \ + unsigned type: (unsigned type)0, \ + signed type: (signed type)0 + +#define __unqual_scalar_typeof(x) typeof( \ + _Generic((x), \ + char: (char)0, \ + __scalar_type_to_expr_cases(char), \ + __scalar_type_to_expr_cases(short), \ + __scalar_type_to_expr_cases(int), \ + __scalar_type_to_expr_cases(long), \ + __scalar_type_to_expr_cases(long long), \ + default: (x))) +#endif + /* Is this type a native word size -- useful for atomic operations */ #define __native_word(t) \ (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || \ |