Masahiro, could you please pick this up? The lore link is below in case it is no longer in your inbox (or I can resend). https://lore.kernel.org/20241017-disable-two-clang-enum-warnings-v2-1-163ac04346ae@xxxxxxxxxx/ On Thu, Oct 17, 2024 at 10:09:22AM -0700, Nathan Chancellor wrote: > -Wenum-enum-conversion was strengthened in clang-19 to warn for C, which > caused the kernel to move it to W=1 in commit 75b5ab134bb5 ("kbuild: > Move -Wenum-{compare-conditional,enum-conversion} into W=1") because > there were numerous instances that would break builds with -Werror. > Unfortunately, this is not a full solution, as more and more developers, > subsystems, and distributors are building with W=1 as well, so they > continue to see the numerous instances of this warning. > > Since the move to W=1, there have not been many new instances that have > appeared through various build reports and the ones that have appeared > seem to be following similar existing patterns, suggesting that most > instances of this warning will not be real issues. The only alternatives > for silencing this warning are adding casts (which is generally seen as > an ugly practice) or refactoring the enums to macro defines or a unified > enum (which may be undesirable because of type safety in other parts of > the code). > > Move the warning to W=2, where warnings that occur frequently but may be > relevant should reside. > > Cc: stable@xxxxxxxxxxxxxxx > Fixes: 75b5ab134bb5 ("kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1") > Link: https://lore.kernel.org/ZwRA9SOcOjjLJcpi@xxxxxxxxxx/ > Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> > --- > Changes in v2: > - Move -Wenum-enum-conversion to W=2, instead of disabling it > outright (Arnd) > - Leave -Wenum-compare-conditional in W=1, as there are not that > many instances, so it can be turned on fully at some point (Arnd) > - Link to v1: https://lore.kernel.org/r/20241016-disable-two-clang-enum-warnings-v1-1-ae886d7a0269@xxxxxxxxxx > --- > scripts/Makefile.extrawarn | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn > index 1d13cecc7cc7808610e635ddc03476cf92b3a8c1..04faf15ed316a9c291dc952b6cc40fb6c8c330cf 100644 > --- a/scripts/Makefile.extrawarn > +++ b/scripts/Makefile.extrawarn > @@ -130,7 +130,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) > KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare > KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) > KBUILD_CFLAGS += -Wno-enum-compare-conditional > -KBUILD_CFLAGS += -Wno-enum-enum-conversion > endif > > endif > @@ -154,6 +153,10 @@ KBUILD_CFLAGS += -Wno-missing-field-initializers > KBUILD_CFLAGS += -Wno-type-limits > KBUILD_CFLAGS += -Wno-shift-negative-value > > +ifdef CONFIG_CC_IS_CLANG > +KBUILD_CFLAGS += -Wno-enum-enum-conversion > +endif > + > ifdef CONFIG_CC_IS_GCC > KBUILD_CFLAGS += -Wno-maybe-uninitialized > endif > > --- > base-commit: 8e929cb546ee42c9a61d24fae60605e9e3192354 > change-id: 20241016-disable-two-clang-enum-warnings-e7994d44f948 > > Best regards, > -- > Nathan Chancellor <nathan@xxxxxxxxxx> >
