https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82323
--- Comment #6 from Bernd Edlinger <bernd.edlinger at hotmail dot de> --- I wonder why this condition on the warning is symmetrical: (!FUNC_OR_METHOD_TYPE_P (t2) || (prototype_p (t1) && prototype_p (t2) && !types_compatible_p (t1, t2)))) I mean if you have this example void f() __attribute__((alias("g"))); int g(int a) { return a; } only f can be w/o prototype, but g has to use the correct argument list; thus the term "prototype_p (t2)" should be removed from the condition.