Linux下C++编译Protobuf时链接失败问题求助

问题场景 #

编写极简Protobuf C++示例时遭遇链接错误，尝试显式指定库路径等操作均无法解决问题。

相关文件与编译步骤 #

1. Proto定义文件 tempproj.proto：

package tempproj;
message name
{
    required string first = 1;
    required string last = 2;
}

2. 编译Proto文件生成C++代码：

protoc --cpp_out=. tempproj.proto

生成tempproj.pb.h和tempproj.pb.cc文件。

3. 测试代码main.cpp：

#include "tempproj.bh.h"

int main(int argc, char** argv)
{
     return 0;
}

4. 编译测试代码的命令：

g++ -std=gnu++14 -m64 -lprotobuf main.cpp tempproj.pb.cc

即使显式指定库路径：

g++ -std=gnu++14 -m64 -L/usr/lib64 -lprotobuf main.cpp tempproj.pb.cc

仍出现以下链接错误：

/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o: in function `protobuf_tempproj_2eproto::protobuf_AssignDescriptors()':
tempproj.pb.cc:(.text+0xf6): undefined reference to `google::protobuf::internal::AssignDescriptors(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, google::protobuf::internal::MigrationSchema const*, google::protobuf::Message const* const*, unsigned int const*, google::protobuf::MessageFactory*, google::protobuf::Metadata*, google::protobuf::EnumDescriptor const**, google::protobuf::ServiceDescriptor const**)'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o: in function `protobuf_tempproj_2eproto::AddDescriptorsImpl()':
tempproj.pb.cc:(.text+0x1a5): undefined reference to `google::protobuf::MessageFactory::InternalRegisterGeneratedFile(char const*, void (*)(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&))'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o: in function `tempproj::name::SerializeWithCachedSizes(google::protobuf::io::CodedOutputStream*) const':
tempproj.pb.cc:(.text+0xcb9): undefined reference to `google::protobuf::internal::WireFormatLite::WriteStringMaybeAliased(int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, google::protobuf::io::CodedOutputStream*)'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: tempproj.pb.cc:(.text+0xd24): undefined reference to `google::protobuf::internal::WireFormatLite::WriteStringMaybeAliased(int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, google::protobuf::io::CodedOutputStream*)'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o: in function `google::protobuf::internal::GetEmptyStringAlreadyInited[abi:cxx11]()':
tempproj.pb.cc:(.text._ZN6google8protobuf8internal27GetEmptyStringAlreadyInitedB5cxx11Ev[_ZN6google8protobuf8internal27GetEmptyStringAlreadyInitedB5cxx11Ev]+0x5): undefined reference to `google::protobuf::internal::fixed_address_empty_string[abi:cxx11]'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o: in function `google::protobuf::internal::WireFormatLite::ReadString(google::protobuf::io::CodedInputStream*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*)':
tempproj.pb.cc:(.text._ZN6google8protobuf8internal14WireFormatLite10ReadStringEPNS0_2io16CodedInputStreamEPNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE[_ZN6google8protobuf8internal14WireFormatLite10ReadStringEPNS0_2io16CodedInputStreamEPNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE]+0x1f): undefined reference to `google::protobuf::internal::WireFormatLite::ReadBytes(google::protobuf::io::CodedInputStream*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*)'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o: in function `google::protobuf::internal::WireFormatLite::WriteStringToArray(int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned char*)':
tempproj.pb.cc:(.text._ZN6google8protobuf8internal14WireFormatLite18WriteStringToArrayEiRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEPh[_ZN6google8protobuf8internal14WireFormatLite18WriteStringToArrayEiRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEPh]+0x39): undefined reference to `google::protobuf::io::CodedOutputStream::WriteStringWithSizeToArray(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned char*)'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o:(.rodata._ZTVN8tempproj4nameE[_ZTVN8tempproj4nameE]+0x20): undefined reference to `google::protobuf::Message::GetTypeName[abi:cxx11]() const'
/opt/rh/gcc-toolset-11/root/usr/bin/ld: /tmp/ccj7rSmF.o:(.rodata._ZTVN8tempproj4nameE[_ZTVN8tempproj4nameE]+0x58): undefined reference to `google::protobuf::Message::InitializationErrorString[abi:cxx11]() const'
collect2: error: ld returned 1 exit status

环境说明：使用EL8系统，gcc-toolset-11（g++ 11.2.1），头文件路径为/usr/include，库文件路径为/usr/lib64。

解决方法 #

编译时添加-D_GLIBCXX_USE_CXX11_ABI=0选项，命令如下：

g++ -std=gnu++14 -m64 -D_GLIBCXX_USE_CXX11_ABI=0 -lprotobuf main.cpp tempproj.pb.cc

原因说明 #

GCC 5及后续版本默认启用了新的C++11 ABI（基于std::__cxx11命名空间），而系统预装的Protobuf库是用旧ABI编译的。两者ABI不兼容，导致链接时无法找到匹配的符号。添加该编译选项可强制编译器使用旧ABI，与系统库的ABI保持一致，从而解决链接错误。

内容的提问来源于stack exchange，提问作者basil