https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78014
--- Comment #2 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- I think this is essentially the same as bug 77970 - making such warnings smarter about the case of standard typedefs. Of course an expression resulting from sizeof must be considered appropriate for %zu. Likewise _Alignof. Likewise SIZE_MAX, but headers or predefines just define it to use an appropriate constant suffix, so without looking at the macro being expanded there's nothing to distinguish it from any constant where the user wrong such a suffix directly. Likewise an expression where the user did "typedef size_t my_size_t;" and then used my_size_t. And what about expressions resulting from arithmetic on size_t values? So it may be hard for the compiler to tell exactly what expressions are appropriate for use with %zu (even without direct use of __SIZE_TYPE__).
