On Mon, Apr 12, 2021 at 11:12 PM Yonghong Song <yhs@xxxxxx> wrote: > > > > On 4/12/21 9:32 PM, Andrii Nakryiko wrote: > > On Sat, Apr 10, 2021 at 9:49 AM Yonghong Song <yhs@xxxxxx> wrote: > >> > >> With clang compiler: > >> make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel > >> make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 > >> the test_cpp build failed due to the failure: > >> warning: treating 'c-header' input as 'c++-header' when in C++ mode, this behavior is deprecated [-Wdeprecated] > >> clang-13: warning: cannot specify -o when generating multiple output files > >> > >> test_cpp compilation flag looks like: > >> clang++ -g -Og -rdynamic -Wall -I<...> ... \ > >> -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program \ > >> test_cpp.cpp <...>/test_core_extern.skel.h <...>/libbpf.a <...>/test_stub.o \ > >> -lcap -lelf -lz -lrt -lpthread -o <...>/test_cpp > >> > >> The clang++ compiler complains the header file in the command line. > >> Let us remove the header file from the command line which is not intended > >> any way, and this fixed the problem. > >> > >> Signed-off-by: Yonghong Song <yhs@xxxxxx> > >> --- > >> tools/testing/selftests/bpf/Makefile | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > >> index 6448c626498f..bbd61cc3889b 100644 > >> --- a/tools/testing/selftests/bpf/Makefile > >> +++ b/tools/testing/selftests/bpf/Makefile > >> @@ -481,7 +481,7 @@ $(OUTPUT)/test_verifier: test_verifier.c verifier/tests.h $(BPFOBJ) | $(OUTPUT) > >> # Make sure we are able to include and link libbpf against c++. > >> $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ) > >> $(call msg,CXX,,$@) > >> - $(Q)$(CXX) $(CFLAGS) $^ $(LDLIBS) -o $@ > >> + $(Q)$(CXX) $(CFLAGS) test_cpp.cpp $(BPFOBJ) $(LDLIBS) -o $@ > > > > see what we do for other binaries: > > > > $(filter %.a %.o %.c,$^) > > > > It's more generic. Add %.cpp, of course. > > Okay, although I will remove %.c. > > [yhs@devbig003.ftw2 ~/tmp/tmp2]$ clang++ -c t.c > clang-13: warning: treating 'c' input as 'c++' when in C++ mode, this > behavior is deprecated [-Wdeprecated] > [yhs@devbig003.ftw2 ~/tmp/tmp2]$ > > clang++ will warn if trying to compile .c file. > g++ 8.4.1 doesn't warn. Not sure about latest g++. But it is not > a good practice to compile .c files with c++ compiler any way. yeah, makes sense > > > > >> > >> # Benchmark runner > >> $(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h > >> -- > >> 2.30.2 > >>
