On 12/21, Anton Protopopov wrote:
Since the eb9d1acf634b commit ("bpftool: Add LLVM as default library for
disassembling JIT-ed programs") we might link the bpftool program with the
libllvm library. This works fine when a dynamically built libllvm
available,
but fails if we want to link bpftool with a statically built llvm:
/usr/bin/ld:
/usr/local/lib/libLLVMSupport.a(CrashRecoveryContext.cpp.o): in function
`llvm::CrashRecoveryContextCleanup::~CrashRecoveryContextCleanup()':
CrashRecoveryContext.cpp:(.text._ZN4llvm27CrashRecoveryContextCleanupD0Ev+0x17):
undefined reference to `operator delete(void*, unsigned long)'
/usr/bin/ld:
/usr/local/lib/libLLVMSupport.a(CrashRecoveryContext.cpp.o): in function
`llvm::CrashRecoveryContext::~CrashRecoveryContext()':
CrashRecoveryContext.cpp:(.text._ZN4llvm20CrashRecoveryContextD2Ev+0xc8):
undefined reference to `operator delete(void*, unsigned long)'
...
To fix this we need to explicitly link bpftool with required libraries,
namely,
libstdc++ and those provided by `llvm-config --system-libs`. This patch
doesn't change the build with a dynamically built libllvm, as the
`llvm-config
--system-libs` list is empty in this case, and the bpftool is linked with
the
libstdc++ in any case as this is a dynamic dependency of libLLVM.so.
eb9d1acf634b commit ("bpftool: Add LLVM as default library for
disassembling JIT-ed programs")
Signed-off-by: Anton Protopopov <aspsk@xxxxxxxxxxxxx>
---
tools/bpf/bpftool/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 787b857d3fb5..e4c15095eac7 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -144,7 +144,7 @@ ifeq ($(feature-llvm),1)
CFLAGS += -DHAVE_LLVM_SUPPORT
LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
CFLAGS += $(shell $(LLVM_CONFIG) --cflags --libs
$(LLVM_CONFIG_LIB_COMPONENTS))
- LIBS += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
+ LIBS += $(shell $(LLVM_CONFIG) --libs --system-libs
$(LLVM_CONFIG_LIB_COMPONENTS)) -lstdc++
Why not do separate lines? We can then maybe do a bit safer approach?
LIBS += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
ifeq ($(USE_STATIC_COMPONENTS), static)
LIBS += $(shell $(LLVM_CONFIG) --system-libs))
LIBS += -lstdc++
endif
Can we use `llvm-config --shared-mode` to get USE_STATIC_COMPONENTS?
LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
else
# Fall back on libbfd
--
2.34.1
