A common use of type_max() is to find the max for the type of a
variable. Using the pattern type_max(typeof(var)) is needlessly
verbose. Instead, since typeof(type) == type we can just explicitly
call typeof() on the argument to type_max() and type_min(). Add
wrappers for readability.
We can do some replacements right away:
$ git grep '\btype_\(min\|max\)(typeof' | wc -l
11
Link: https://lore.kernel.org/r/20240301062221.work.840-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
* credit to Christian Biere.
*/
#define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type)))
* credit to Christian Biere.
*/
#define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type)))
-#define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T)))
-#define type_min(T) ((T)((T)-type_max(T)-(T)1))
+#define __type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T)))
+#define type_max(t) __type_max(typeof(t))
+#define __type_min(T) ((T)((T)-type_max(T)-(T)1))
+#define type_min(t) __type_min(typeof(t))
/*
* Avoids triggering -Wtype-limits compilation warning,
/*
* Avoids triggering -Wtype-limits compilation warning,
#define __overflows_type_constexpr(x, T) ( \
is_unsigned_type(typeof(x)) ? \
#define __overflows_type_constexpr(x, T) ( \
is_unsigned_type(typeof(x)) ? \
- (x) > type_max(typeof(T)) : \
is_unsigned_type(typeof(T)) ? \
is_unsigned_type(typeof(T)) ? \
- (x) < 0 || (x) > type_max(typeof(T)) : \
- (x) < type_min(typeof(T)) || (x) > type_max(typeof(T)))
+ (x) < 0 || (x) > type_max(T) : \
+ (x) < type_min(T) || (x) > type_max(T))
#define __overflows_type(x, T) ({ \
typeof(T) v = 0; \
#define __overflows_type(x, T) ({ \
typeof(T) v = 0; \