diff options
Diffstat (limited to 'include/linux/compiler-gcc.h')
| -rw-r--r-- | include/linux/compiler-gcc.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 5c8351b859f0..9bf1cf1563ea 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -61,3 +61,22 @@ #define noinline __attribute__((noinline)) #define __attribute_const__ __attribute__((__const__)) #define __maybe_unused __attribute__((unused)) + +/** + * cast_if_type - allow an alternate type + * @expr: the expression to optionally cast + * @oktype: the type to allow. + * @desttype: the type to cast to. + * + * This is used to accept a particular alternate type for an expression: + * because any other types will not be cast, they will cause a warning as + * normal. + * + * Note that the unnecessary trinary forces functions to devolve into + * function pointers as users expect, but means @expr must be a pointer or + * integer. + */ +#define cast_if_type(expr, oktype, desttype) \ + __builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(expr):0),\ + oktype), \ + (desttype)(expr), (expr)) |