On 12/22, 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 shared libllvm library is
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)'
...
So in the case of static libllvm we need to explicitly link bpftool with
required libraries, namely, libstdc++ and those provided by the
`llvm-config
--system-libs` command. We can distinguish between the shared and static
cases
by using the `llvm-config --shared-mode` command.
eb9d1acf634b commit ("bpftool: Add LLVM as default library for
disassembling JIT-ed programs")
Signed-off-by: Anton Protopopov <aspsk@xxxxxxxxxxxxx>
Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Thank you!
---
v2:
Use llvm-config to distinguish between shared and static modes
(Stanislav)
tools/bpf/bpftool/Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 313fd1b09189..ab20ecc5acce 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -145,6 +145,10 @@ ifeq ($(feature-llvm),1)
LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
CFLAGS += $(shell $(LLVM_CONFIG) --cflags --libs
$(LLVM_CONFIG_LIB_COMPONENTS))
LIBS += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
+ ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static)
+ LIBS += $(shell $(LLVM_CONFIG) --system-libs
$(LLVM_CONFIG_LIB_COMPONENTS))
+ LIBS += -lstdc++
+ endif
LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
else
# Fall back on libbfd
--
2.34.1
