On Sat, Apr 10, 2021 at 6:49 PM 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 $@ > > # Benchmark runner > $(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h > -- > 2.30.2 > NOTE: bpf-next might be different from my build-environment. Yonghong, can you please re-test by adding explicitly CXX=g++ to your make line? Here I have: $ grep test_cpp make-log_tools-testing-selftests-bpf_clang_clang++.txt 1907:clang++ -g -rdynamic -Wall -O2 -DHAVE_GENHDR -I/home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf -I/home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/tools/include -I/home/dileks/src/linux-kernel/git/include/generated -I/home/dileks/src/linux-kernel/git/tools/lib -I/home/dileks/src/linux-kernel/git/tools/include -I/home/dileks/src/linux-kernel/git/tools/include/uapi -I/home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf -Wno-unused-command-line-argument -Wno-format-security -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program test_cpp.cpp /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.a -lcap -lelf -lz -lrt -lpthread -o /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/test_cpp This clang++ line does not include <...>/test_core_extern.skel.h ^^^ $ grep test_core_extern.skel.h make-log_tools-testing-selftests-bpf_clang_clang++.txt 704:/home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/tools/sbin/bpftool gen skeleton /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/test_co re_extern.o > /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/test_core_extern.skel.h 1592:/home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/tools/sbin/bpftool gen skeleton /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/no_alu 32/test_core_extern.o > /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/no_alu32/test_core_extern.skel.h Checking test_cpp: $ /opt/llvm-toolchain/bin/llvm-objdump-12 -Dr test_cpp | grep extern 0000000000417e50 <cmp_externs>: 417e54: 75 22 jne 0x417e78 <cmp_externs+0x28> 417e59: 75 10 jne 0x417e6b <cmp_externs+0x1b> 417e61: 75 21 jne 0x417e84 <cmp_externs+0x34> 417e69: 75 1e jne 0x417e89 <cmp_externs+0x39> 417e87: eb f2 jmp 0x417e7b <cmp_externs+0x2b> 417e8c: eb ed jmp 0x417e7b <cmp_externs+0x2b> $ /opt/llvm-toolchain/bin/llvm-objdump-12 -Dr test_cpp | grep core_extern [ EMPTY ] When compiled with g++ in an earlier setup this contained "core_extern". With this version of your patchser it breaks *here* when using CXX=g++ (and uses /usr/bin/ld as linker): g++ -g -rdynamic -Wall -O2 -DHAVE_GENHDR -I/home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf -I/home/dileks/src/linux-kernel/git/tools/testing/selftests/b pf/tools/include -I/home/dileks/src/linux-kernel/git/include/generated -I/home/dileks/src/linux-kernel/git/tools/lib -I/home/dileks/src/linux-kernel/git/tools/include -I/home/dileks/src/linux-kernel/git/tools/include/uapi -I/home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf -Wno-unused-command-line-argument -Wno-format-security -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program test_cpp.cpp /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.a -lcap -lelf -lz -lrt -lpthread -o /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/test_cpp /usr/bin/ld: /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.a(libbpf-in.o): relocation R_X86_64_32 against `.rodata.str1.1' ca n not be used when making a PIE object; recompile with -fPIE collect2: error: ld returned 1 exit status make: *** [Makefile:457: /home/dileks/src/linux-kernel/git/tools/testing/selftests/bpf/test_cpp] Error 1 $ grep test_cpp ../make-log_tools-testing-selftests-bpf_clang_g++.txt | grep test_core_extern.skel.h [ EMPTY ] As said I do NOT use bpf-next. - Sedat - - Sedat -
