On 05/05/2024 22:56, John Hubbard wrote:
When building either tools/bpf/bpftool, or tools/testing/selftests/hid, (the same Makefile is used for these), clang generates many instances of a warning that is useless here:
"clang: warning: -lLLVM-17: 'linker' input unused"Silence this in both locations, by disabling that warning when building with clang.
Signed-off-by: John Hubbard jhubbard@nvidia.com
tools/bpf/bpftool/Makefile | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index e9154ace80ff..c7457921d136 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -133,6 +133,10 @@ CFLAGS += -DUSE_LIBCAP LIBS += -lcap endif +ifneq ($(LLVM),)
- CFLAGS += -Wno-unused-command-line-argument
+endif
Thanks! If possible, I'd rather keep the warning enabled, and fix the command line instead. Looking at the error and the Makefile, we may not need the -lLLVM<version> in the CFLAGS at all, but only in $(LIBS). On my setup, I can build successfully, without the warnings, with the following patch:
------ diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index b67454b45a49..dfa4f1bebbb3 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -147,7 +147,7 @@ ifeq ($(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 --libs $(LLVM_CONFIG_LIB_COMPONENTS)) + CFLAGS += $(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)) ------
Could you please check whether that works on your side, too?
Quentin