On Fri, May 31, 2024 at 11:37:51AM -0700, John Hubbard wrote: > gcc defaults to silence (off) for the following warnings, but clang > defaults to the opposite. The warnings are not useful for the kernel > itself, which is why they have remained disabled in gcc for the main > kernel build. And it is only due to including kernel data structures in > the selftests, that we get the warnings from clang. > > -Waddress-of-packed-member > -Wgnu-variable-sized-type-not-at-end > > In other words, the warnings are not unique to the selftests: there is > nothing that the selftests' code does that triggers these warnings, > other than the act of including the kernel's data structures. Therefore, > silence them for the clang builds as well. > > This eliminates warnings for the net/ and user_events/ kselftest > subsystems, in these files: > > ./net/af_unix/scm_rights.c > ./net/timestamping.c > ./net/ipsec.c > ./user_events/perf_test.c > > Cc: Nathan Chancellor <nathan@xxxxxxxxxx> > Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> This seems reasonable to me. Acked-by: Nathan Chancellor <nathan@xxxxxxxxxx> > --- > tools/testing/selftests/lib.mk | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk > index 2902787b89b2..c179c02281e9 100644 > --- a/tools/testing/selftests/lib.mk > +++ b/tools/testing/selftests/lib.mk > @@ -50,6 +50,14 @@ else > CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) > endif # CROSS_COMPILE > > +# gcc defaults to silence (off) for the following warnings, but clang defaults > +# to the opposite. The warnings are not useful for the kernel itself, which is > +# why they have remained disabled in gcc for the main kernel build. And it is > +# only due to including kernel data structures in the selftests, that we get the > +# warnings from clang. Therefore, disable the warnings for clang builds. > +CFLAGS += -Wno-address-of-packed-member > +CFLAGS += -Wno-gnu-variable-sized-type-not-at-end > + > CC := $(CLANG) $(CLANG_FLAGS) -fintegrated-as > else > CC := $(CROSS_COMPILE)gcc > -- > 2.45.1 > >
