diff options
| author | Viktor Malik <vmalik@redhat.com> | 2024-11-01 09:27:12 +0100 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-11-01 12:37:01 -0700 |
| commit | 0513eeee86d67930f3567e450357d8db1cfb4f16 (patch) | |
| tree | c47d5fd9ae37e56823382f57e2fb793516dcb9b6 /tools/bpf | |
| parent | 4d99e509c161f8610de125202c648fa4acd00541 (diff) | |
bpftool: Prevent setting duplicate _GNU_SOURCE in Makefile
When building selftests with CFLAGS set via env variable, the value of
CFLAGS is propagated into bpftool Makefile (called from selftests
Makefile). This makes the compilation fail as _GNU_SOURCE is defined two
times - once from selftests Makefile (by including lib.mk) and once from
bpftool Makefile (by calling `llvm-config --cflags`):
$ CFLAGS="" make -C tools/testing/selftests/bpf
[...]
CC /bpf-next/tools/testing/selftests/bpf/tools/build/bpftool/btf.o
<command-line>: error: "_GNU_SOURCE" redefined [-Werror]
<command-line>: note: this is the location of the previous definition
cc1: all warnings being treated as errors
[...]
Filter out -D_GNU_SOURCE from the result of `llvm-config --cflags` in
bpftool Makefile to prevent this error.
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/acec3108b62d4df1436cda777e58e93e033ac7a7.1730449390.git.vmalik@redhat.com
Diffstat (limited to 'tools/bpf')
| -rw-r--r-- | tools/bpf/bpftool/Makefile | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index ba927379eb20..a4263dfb5e03 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -147,7 +147,11 @@ ifeq ($(feature-llvm),1) # If LLVM is available, use it for JIT disassembly CFLAGS += -DHAVE_LLVM_SUPPORT LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets - CFLAGS += $(shell $(LLVM_CONFIG) --cflags) + # llvm-config always adds -D_GNU_SOURCE, however, it may already be in CFLAGS + # (e.g. when bpftool build is called from selftests build as selftests + # Makefile includes lib.mk which sets -D_GNU_SOURCE) which would cause + # compilation error due to redefinition. Let's filter it out here. + CFLAGS += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags)) LIBS += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS)) ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static) LIBS += $(shell $(LLVM_CONFIG) --system-libs $(LLVM_CONFIG_LIB_COMPONENTS)) |