c++ - 我的项目不会编译出现 undefined reference 错误，如 "undefined reference to ` grpc::g_core_codegen_interface'"

Question

我刚刚使用 gRPC 实现了一个数据库项目的分布式版本。当我尝试使用我的 makefile 进行制作时，我不断收到 protobuf 和 gRPC 的 undefined reference 错误。 make 的部分输出如下。由于字数限制，我只包含了其中的一部分。

g++ -o rundb benchmarks/ycsb_query.o benchmarks/tpcc_wl.o benchmarks/ycsb_wl.o benchmarks/ycsb_store_procedure.o benchmarks/tpcc_query.o benchmarks/tpcc_helper.o benchmarks/tpcc_store_procedure.o concurrency_control/lock_manager.o concurrency_control/tictoc_manager.o concurrency_control/row_f1.o concurrency_control/row_lock.o concurrency_control/f1_manager.o concurrency_control/row_tictoc.o storage/catalog.o storage/index_hash.o storage/index_btree.o storage/index_base.o storage/row.o storage/log.o storage/table.o system/stats.o system/manager.o system/cc_manager.o system/thread.o system/global.o system/logging_thread.o system/store_procedure.o system/txn.o system/worker_thread.o system/parser.o system/workload.o system/txn_table.o system/main.o system/caching.o utils/helper.o utils/semaphore_sync.o utils/packetize.o grpc/grpc_async_client.o grpc/grpc_sync_server.o grpc/grpc_async_server.o grpc/grpc_sync_client.o -Wall -L./libs -pthread -lrt -std=c++0x -O3 -ljemalloc -lprotobuf -Wall -g -std=c++11 -I. -I./benchmarks -I./concurrency_control -I./storage -I./system -I./transport -I./utils -I./grpc -I./grpc_system -D NOGRAPHITE=1 -O3 -g -ggdb
/usr/bin/ld: concurrency_control/lock_manager.o: in function `google::protobuf::internal::GenericTypeHandler<sundial_rpc::SundialRequest_TupleData>::New(google::protobuf::Arena*)':
/usr/local/include/google/protobuf/repeated_field.h:802: undefined reference to `sundial_rpc::SundialRequest_TupleData* google::protobuf::Arena::CreateMaybeMessage<sundial_rpc::SundialRequest_TupleData>(google::protobuf::Arena*)'
/usr/bin/ld: system/stats.o: in function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const& sundial_rpc::SundialRequest_RequestType_Name<unsigned int>(unsigned int)':
/home/libin/Sundial/./grpc_system/sundial_grpc.pb.h:105: undefined reference to `sundial_rpc::SundialRequest_RequestType_descriptor()'
/usr/bin/ld: system/stats.o: in function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const& sundial_rpc::SundialResponse_ResponseType_Name<unsigned int>(unsigned int)':
/home/libin/Sundial/./grpc_system/sundial_grpc.pb.h:136: undefined reference to `sundial_rpc::SundialResponse_ResponseType_descriptor()'
/usr/bin/ld: system/txn.o: in function `google::protobuf::internal::GenericTypeHandler<sundial_rpc::SundialResponse_TupleData>::New(google::protobuf::Arena*)':
/usr/local/include/google/protobuf/repeated_field.h:802: undefined reference to `sundial_rpc::SundialResponse_TupleData* google::protobuf::Arena::CreateMaybeMessage<sundial_rpc::SundialResponse_TupleData>(google::protobuf::Arena*)'
/usr/bin/ld: system/txn.o: in function `TxnManager::RemoteNodeInfo::~RemoteNodeInfo()':
/home/libin/Sundial/system/txn.h:102: undefined reference to `sundial_rpc::SundialResponse::~SundialResponse()'
/usr/bin/ld: /home/libin/Sundial/system/txn.h:102: undefined reference to `sundial_rpc::SundialRequest::~SundialRequest()'
/usr/bin/ld: system/txn.o: in function `sundial_rpc::SundialRequest::SundialRequest()':
/home/libin/Sundial/./grpc_system/sundial_grpc.pb.h:494: undefined reference to `sundial_rpc::SundialRequest::SundialRequest(google::protobuf::Arena*)'
/usr/bin/ld: system/txn.o: in function `sundial_rpc::SundialResponse::SundialResponse()':
/home/libin/Sundial/./grpc_system/sundial_grpc.pb.h:909: undefined reference to `sundial_rpc::SundialResponse::SundialResponse(google::protobuf::Arena*)'
/usr/bin/ld: system/txn.o: in function `TxnManager::send_remote_read_request(unsigned long, unsigned long, unsigned long, unsigned long, access_t)':
/home/libin/Sundial/system/txn.cpp:301: undefined reference to `sundial_rpc::SundialRequest::Clear()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:302: undefined reference to `sundial_rpc::SundialResponse::Clear()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:309: undefined reference to `sundial_rpc::SundialResponse::SundialResponse(sundial_rpc::SundialResponse const&)'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:309: undefined reference to `sundial_rpc::SundialRequest::SundialRequest(sundial_rpc::SundialRequest const&)'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:309: undefined reference to `sundial_rpc::SundialRequest::~SundialRequest()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:309: undefined reference to `sundial_rpc::SundialResponse::~SundialResponse()'
/usr/bin/ld: system/txn.o: in function `google::protobuf::internal::GenericTypeHandler<sundial_rpc::SundialRequest_ReadRequest>::New(google::protobuf::Arena*)':
/usr/local/include/google/protobuf/repeated_field.h:802: undefined reference to `sundial_rpc::SundialRequest_ReadRequest* google::protobuf::Arena::CreateMaybeMessage<sundial_rpc::SundialRequest_ReadRequest>(google::protobuf::Arena*)'
/usr/bin/ld: system/txn.o: in function `TxnManager::process_2pc_phase1()':
/home/libin/Sundial/system/txn.cpp:351: undefined reference to `sundial_rpc::SundialRequest::Clear()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:352: undefined reference to `sundial_rpc::SundialResponse::Clear()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:362: undefined reference to `sundial_rpc::SundialResponse::SundialResponse(sundial_rpc::SundialResponse const&)'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:362: undefined reference to `sundial_rpc::SundialRequest::SundialRequest(sundial_rpc::SundialRequest const&)'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:362: undefined reference to `sundial_rpc::SundialRequest::~SundialRequest()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:362: undefined reference to `sundial_rpc::SundialResponse::~SundialResponse()'
/usr/bin/ld: system/txn.o: in function `TxnManager::process_2pc_phase2(RC)':
/home/libin/Sundial/system/txn.cpp:420: undefined reference to `sundial_rpc::SundialRequest::Clear()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:421: undefined reference to `sundial_rpc::SundialResponse::Clear()'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:429: undefined reference to `sundial_rpc::SundialResponse::SundialResponse(sundial_rpc::SundialResponse const&)'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:429: undefined reference to `sundial_rpc::SundialRequest::SundialRequest(sundial_rpc::SundialRequest const&)'
/usr/bin/ld: /home/libin/Sundial/system/txn.cpp:429: undefined reference to `sundial_rpc::SundialRequest::~SundialRequest()'
/usr/bin/ld: /home/libin/Sundial/grpc/grpc_sync_client.cpp:37: undefined reference to `sundial_rpc::Sundial_GRPC_SYNC::Stub::contactRemote(grpc_impl::ClientContext*, sundial_rpc::SundialRequest const&, sundial_rpc::SundialResponse*)'
/usr/bin/ld: /home/libin/Sundial/grpc/grpc_sync_client.cpp:36: undefined reference to `grpc_impl::ClientContext::~ClientContext()'
/usr/bin/ld: grpc/grpc_sync_client.o: in function `sundial_rpc::Sundial_GRPC_SYNC::Stub::~Stub()':
/home/libin/Sundial/./grpc_system/sundial_grpc.grpc.pb.h:73: undefined reference to `vtable for sundial_rpc::Sundial_GRPC_SYNC::Stub'
/usr/bin/ld: grpc/grpc_sync_client.o: in function `sundial_rpc::Sundial_GRPC_SYNC::Stub::~Stub()':
/home/libin/Sundial/./grpc_system/sundial_grpc.grpc.pb.h:73: undefined reference to `vtable for sundial_rpc::Sundial_GRPC_SYNC::Stub'
/usr/bin/ld: grpc/grpc_sync_client.o: in function `Sundial_Sync_Client::contactRemote(unsigned long, sundial_rpc::SundialRequest, sundial_rpc::SundialResponse)':
/home/libin/Sundial/grpc/grpc_sync_client.cpp:36: undefined reference to `grpc_impl::ClientContext::~ClientContext()'
collect2: error: ld returned 1 exit status
make: *** [Makefile:20: rundb] Error 1

我确实阅读了一些其他以前的帖子，表明这是由于未链接 protobuf 库引起的，但我确实将其包含在 LDFLAGS 中。生成文件如下。

CC=g++
CFLAGS=-Wall -g -std=c++11

.SUFFIXES: .o .cpp .h

SRC_DIRS = ./ ./benchmarks/ ./concurrency_control/ ./storage/ ./system/ ./transport/ ./utils/ ./grpc/ ./grpc_system/
INCLUDE = -I. -I./benchmarks -I./concurrency_control -I./storage -I./system -I./transport -I./utils -I./grpc -I./grpc_system

CFLAGS += $(INCLUDE) -D NOGRAPHITE=1 -O3 -g -ggdb
LDFLAGS = -Wall -L./libs -pthread -lrt -std=c++0x -O3 -ljemalloc -lprotobuf
LDFLAGS += $(CFLAGS)

CPPS = $(foreach dir, $(SRC_DIRS), $(wildcard $(dir)*.cpp))
OBJS = $(CPPS:.cpp=.o)
DEPS = $(CPPS:.cpp=.d)

all:rundb

rundb : $(OBJS)
    $(CC) -o $@ $^ $(LDFLAGS)

-include $(OBJS:%.o=%.d)

%.d: %.cpp
    $(CC) -MM -MT $*.o -MF $@ $(CFLAGS) $<

%.o: %.cpp %.d
    $(CC) -c $(CFLAGS) -o $@ $<

.PHONY: clean
clean:
    rm -f rundb *.o */*.o *.d */*.d

所以我认为 LDFLAGS = -Wall -L./libs -pthread -lrt -std=c++0x -O3 -ljemalloc -lprotobuf 会解决这个问题，但事实并非如此。

Answer 1

您可以尝试按照以下两个步骤操作:

第 1 步:

在您的 makefile 中添加以下两行:

CFLAGS += `pkg-config --cflags protobuf grpc`

LDFLAGS += -L/usr/local/lib `pkg-config --libs protobuf grpc++ grpc`\
           -lgrpc++_reflection\
           -ldl

请引用此 Makefile(用于负载平衡的 C++ grpc 示例):https://chromium.googlesource.com/external/github.com/grpc/grpc/+/HEAD/examples/cpp/load_balancing/Makefile

您的 Makefile 应如下所示:

CC=g++
CFLAGS=-Wall -g -std=c++11

# Add the below line
CFLAGS += `pkg-config --cflags protobuf grpc`

.SUFFIXES: .o .cpp .h

SRC_DIRS = ./ ./benchmarks/ ./concurrency_control/ ./storage/ ./system/ ./transport/ ./utils/ ./grpc/ ./grpc_system/
INCLUDE = -I. -I./benchmarks -I./concurrency_control -I./storage -I./system -I./transport -I./utils -I./grpc -I./grpc_system

CFLAGS += $(INCLUDE) -D NOGRAPHITE=1 -O3 -g -ggdb
LDFLAGS = -Wall -L./libs -pthread -lrt -std=c++0x -O3 -ljemalloc -lprotobuf
LDFLAGS += $(CFLAGS)

# Add the below line
LDFLAGS += -L/usr/local/lib `pkg-config --libs protobuf grpc++ grpc`\
           -lgrpc++_reflection\
           -ldl

CPPS = $(foreach dir, $(SRC_DIRS), $(wildcard $(dir)*.cpp))
OBJS = $(CPPS:.cpp=.o)
DEPS = $(CPPS:.cpp=.d)

all:rundb

rundb : $(OBJS)
    $(CC) -o $@ $^ $(LDFLAGS)

-include $(OBJS:%.o=%.d)

%.d: %.cpp
    $(CC) -MM -MT $*.o -MF $@ $(CFLAGS) $<

%.o: %.cpp %.d
    $(CC) -c $(CFLAGS) -o $@ $<

.PHONY: clean
clean:
    rm -f rundb *.o */*.o *.d */*.d

第 2 步:

在命令提示符下，您需要找到两个文件的路径:

1. “protobuf.pc”的路径
2. “grpc.pc”的路径

您可以使用这些命令找到路径:

sudo find / -name "protobuf.pc"
Example output: /usr/local/lib/pkgconfig

sudo find / -name "grpc.pc"
Example output: /usr/lib/pkgconfig"

最后，您需要通过运行以下命令在环境变量“PKG_CONFIG_PATH”中添加这两个以冒号 (:) 分隔的路径:

export PKG_CONFIG_PATH="/usr/local/lib/pkgconfig:/usr/lib/pkgconfig"

现在，您可以运行命令并继续下一步。

注意:

在步骤 2 中，如果 protobuf.pc 和 grpc.pc 都存在于同一目录中，那么您只需要在环境变量中指定该目录即可。

例子:

sudo find / -name "protobuf.pc"
Example output: /lib64/pkgconfig

sudo find / -name "grpc.pc"
Example output: /lib64/pkgconfig

在这种情况下，您可以将环境变量设置为:

export PKG_CONFIG_PATH="/lib64/pkgconfig"