On 10/20/24 19:24, Jiri Olsa wrote: > On Fri, Oct 18, 2024 at 08:49:01AM +0200, Viktor Malik wrote: >> There exist compiler flags supported by GCC but not supported by Clang >> (e.g. -specs=...). Currently, these cannot be passed to BPF selftests >> builds, even when building with GCC, as some binaries (urandom_read and >> liburandom_read.so) are always built with Clang and the unsupported >> flags make the compilation fail (as -Werror is turned on). >> >> Add -Wno-unused-command-line-argument to these rules to suppress such >> errors. >> >> This allows to do things like: >> >> $ CFLAGS="-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1" \ >> make -C tools/testing/selftests/bpf > > hi, > might be my fedora setup, but this example gives me compile error below > even with the patch applied: > > EXT-OBJ [test_progs] testing_helpers.o > In file included from testing_helpers.c:10: > disasm.h:11:10: fatal error: linux/stringify.h: No such file or directory > 11 | #include <linux/stringify.h> > | ^~~~~~~~~~~~~~~~~~~ Aren't you doing `make CFLAGS="..."` instead of `CFLAGS="..." make`? The difference is that the former overrides CFLAGS defined in selftests Makefile and therefore the include dirs are not correctly added. > > jirka > >> >> Without this patch, the compilation would fail with: >> >> [...] >> clang: error: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Werror,-Wunused-command-line-argument] >> make: *** [Makefile:273: /bpf-next/tools/testing/selftests/bpf/liburandom_read.so] Error 1 >> [...] >> >> Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx> >> --- >> tools/testing/selftests/bpf/Makefile | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile >> index 1fc7c38e56b5..3da1a61968b7 100644 >> --- a/tools/testing/selftests/bpf/Makefile >> +++ b/tools/testing/selftests/bpf/Makefile >> @@ -273,6 +273,7 @@ $(OUTPUT)/liburandom_read.so: urandom_read_lib1.c urandom_read_lib2.c liburandom >> $(Q)$(CLANG) $(CLANG_TARGET_ARCH) \ >> $(filter-out -static,$(CFLAGS) $(LDFLAGS)) \ >> $(filter %.c,$^) $(filter-out -static,$(LDLIBS)) \ >> + -Wno-unused-command-line-argument \ >> -fuse-ld=$(LLD) -Wl,-znoseparate-code -Wl,--build-id=sha1 \ >> -Wl,--version-script=liburandom_read.map \ >> -fPIC -shared -o $@ >> @@ -281,6 +282,7 @@ $(OUTPUT)/urandom_read: urandom_read.c urandom_read_aux.c $(OUTPUT)/liburandom_r >> $(call msg,BINARY,,$@) >> $(Q)$(CLANG) $(CLANG_TARGET_ARCH) \ >> $(filter-out -static,$(CFLAGS) $(LDFLAGS)) $(filter %.c,$^) \ >> + -Wno-unused-command-line-argument \ >> -lurandom_read $(filter-out -static,$(LDLIBS)) -L$(OUTPUT) \ >> -fuse-ld=$(LLD) -Wl,-znoseparate-code -Wl,--build-id=sha1 \ >> -Wl,-rpath=. -o $@ >> -- >> 2.47.0 >> >
