On Mon, Sep 26, 2022 at 01:17:18PM -0700, Nick Desaulniers wrote: > + Arnd > > On Mon, Sep 26, 2022 at 12:11 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > --- > > v2: > > - fix comment typo > > - wrap clang pragma to avoid GCC warnings > > - style nit cleanups > > - rename __castable_to_type() to castable_to_type() > > - remove prior overflows_type() definition > > v1: https://lore.kernel.org/lkml/20220926003743.409911-1-keescook@xxxxxxxxxxxx > > diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c > > index f385ca652b74..fffc3f86181d 100644 > > --- a/lib/overflow_kunit.c > > +++ b/lib/overflow_kunit.c > > @@ -16,6 +16,11 @@ > > #include <linux/types.h> > > #include <linux/vmalloc.h> > > > > +/* We're expecting to do a lot of "always true" or "always false" tests. */ > > +#ifdef CONFIG_CC_IS_CLANG > > +#pragma clang diagnostic ignored "-Wtautological-constant-out-of-range-compare" > > +#endif > > Any chance we can reuse parts of __diag_ignore or __diag_clang from > include/linux/compiler_types.h or include/linux/compiler-clang.h > respectively? Hm, I'm not sure how those are supposed to be used. Those defines don't seem to be used externally? > Those are needed for pragmas within preprocessor macros, which we > don't have here, but I suspect they may be more concise to use here. Yeah, I was surprised when I had to wrap it in #ifdef given "clang" is part of the string. > > > +#define TEST_SAME_TYPE(t1, t2, same) do { \ > > + typeof(t1) __t1h = type_max(t1); \ > > + typeof(t1) __t1l = type_min(t1); \ > > + typeof(t2) __t2h = type_max(t2); \ > > + typeof(t2) __t2l = type_min(t2); \ > > Can we use __auto_type here rather than typeof(macro expansion)? I'd rather it stay explicit -- otherwise we start to wander into "oops, we got lucky" territory for what should be a really distinct test case. -- Kees Cook
