| Message ID | 20240529020842.127275-3-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | selftests/lib.mk: LLVM=1, CC=clang, and warnings | expand |
On 5/28/24 20:08, John Hubbard wrote: > gcc defaults to silence (off) for the following warnings, but clang > defaults to the opposite. These warnings are not useful for kselftests, > so silence them for the clang builds as well: Please you add more information on why they aren't useful for kselftests. > > -Wno-address-of-packed-member > -Wno-gnu-variable-sized-type-not-at-end > > 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@kernel.org> > Signed-off-by: John Hubbard <jhubbard@nvidia.com> > --- > tools/testing/selftests/lib.mk | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk > index 2902787b89b2..41e879f3f8a2 100644 > --- a/tools/testing/selftests/lib.mk > +++ b/tools/testing/selftests/lib.mk > @@ -50,6 +50,12 @@ 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. These warnings are not useful for kselftests, so silence them > +# for the clang builds as well. > +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 thanks, -- Shuah
On 5/30/24 7:25 AM, Shuah Khan wrote: > On 5/28/24 20:08, John Hubbard wrote: >> gcc defaults to silence (off) for the following warnings, but clang >> defaults to the opposite. These warnings are not useful for kselftests, >> so silence them for the clang builds as well: > > Please you add more information on why they aren't useful > for kselftests. Ah OK. My wording is a little misleading. The warnings are not useful for the *kernel*, as previous decided by the gcc settings when building the kernel. And it is only only due to including kernel data structures in the selftests, that we get the warnings on clang. So it is not something 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. I can post a v2 to update both the comment and the commit description. thanks,
On 5/30/24 13:28, John Hubbard wrote: > On 5/30/24 7:25 AM, Shuah Khan wrote: >> On 5/28/24 20:08, John Hubbard wrote: >>> gcc defaults to silence (off) for the following warnings, but clang >>> defaults to the opposite. These warnings are not useful for kselftests, >>> so silence them for the clang builds as well: >> >> Please you add more information on why they aren't useful >> for kselftests. > > Ah OK. My wording is a little misleading. The warnings are not useful > for the *kernel*, as previous decided by the gcc settings when building > the kernel. And it is only only due to including kernel data structures > in the selftests, that we get the warnings on clang. > > So it is not something 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. > > I can post a v2 to update both the comment and the commit description. > Yes please. thanks, -- Shuah
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index 2902787b89b2..41e879f3f8a2 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -50,6 +50,12 @@ 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. These warnings are not useful for kselftests, so silence them +# for the clang builds as well. +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
gcc defaults to silence (off) for the following warnings, but clang defaults to the opposite. These warnings are not useful for kselftests, so silence them for the clang builds as well: -Wno-address-of-packed-member -Wno-gnu-variable-sized-type-not-at-end 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@kernel.org> Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- tools/testing/selftests/lib.mk | 6 ++++++ 1 file changed, 6 insertions(+)