From 41c24102af7b6236277a214428b203d51a3462df Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 25 Jul 2024 14:40:29 -0700 Subject: selftests/bpf: Filter out _GNU_SOURCE when compiling test_cpp Jakub reports build failures when merging linux/master with net tree: CXX test_cpp In file included from :454: :2:9: error: '_GNU_SOURCE' macro redefined [-Werror,-Wmacro-redefined] 2 | #define _GNU_SOURCE | ^ :445:9: note: previous definition is here 445 | #define _GNU_SOURCE 1 The culprit is commit cc937dad85ae ("selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk") which unconditionally added -D_GNU_SOUCE to CLFAGS. Apparently clang++ also unconditionally adds it for the C++ targets [0] which causes a conflict. Add small change in the selftests makefile to filter it out for test_cpp. Not sure which tree it should go via, targeting bpf for now, but net might be better? 0: https://stackoverflow.com/questions/11670581/why-is-gnu-source-defined-by-default-and-how-to-turn-it-off Signed-off-by: Stanislav Fomichev Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20240725214029.1760809-1-sdf@fomichev.me --- tools/testing/selftests/bpf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index dd49c1d23a60..81d4757ecd4c 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -713,7 +713,7 @@ $(OUTPUT)/xdp_features: xdp_features.c $(OUTPUT)/network_helpers.o $(OUTPUT)/xdp # 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) $(filter %.a %.o %.cpp,$^) $(LDLIBS) -o $@ + $(Q)$(CXX) $(subst -D_GNU_SOURCE=,,$(CFLAGS)) $(filter %.a %.o %.cpp,$^) $(LDLIBS) -o $@ # Benchmark runner $(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h $(BPFOBJ) -- cgit v1.2.3