On Fri, Mar 27, 2020 at 4:42 AM Nathan Chancellor <natechancellor@xxxxxxxxx> wrote: > > Currently, we disable -Wtautological-compare, which in turn disables a > bunch of more specific tautological comparison warnings that are useful > for the kernel such as -Wtautological-bitwise-compare. See clang's > documentation below for the other warnings that are suppressed by > -Wtautological-compare. Now that all of the major/noisy warnings have > been fixed, enable -Wtautological-compare so that more issues can be > caught at build time by various continuous integration setups. > > -Wtautological-constant-out-of-range-compare is kept disabled under a > normal build but visible at W=1 because there are places in the kernel > where a constant or variable size can change based on the kernel > configuration. These are not fixed in a clean/concise way and the ones > I have audited so far appear to be harmless. It is not a subgroup but > rather just one warning so we do not lose out on much coverage by > default. > > Link: https://github.com/ClangBuiltLinux/linux/issues/488 > Link: http://releases.llvm.org/10.0.0/tools/clang/docs/DiagnosticsReference.html#wtautological-compare > Link: https://bugs.llvm.org/show_bug.cgi?id=42666 > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > --- > > v1 -> v2: https://lore.kernel.org/lkml/20200219045423.54190-7-natechancellor@xxxxxxxxx/ > > * Expand commit message a bit by adding more reasoning behind change. > * Disable -Wtautological-constant-out-of-range-compare under a normal > build but allow it to show up at W=1 for easy auditing. > > I hope this can be accepted for 5.7. There are two warnings that I see > still across a bunch of allyesconfig/allmodconfig builds that have > patches sent but not accepted. I will ping them today. > > * https://lore.kernel.org/lkml/20191023002014.22571-1-natechancellor@xxxxxxxxx/ > * https://lore.kernel.org/lkml/20200220051011.26113-1-natechancellor@xxxxxxxxx/ OK, I will queue this up and send it to Linus in the second week of MW. I hope all warnings will be fixed by that time. -- Best Regards Masahiro Yamada
