unresolved external symbol - GRPC - c++

Question

I complied c++ grpc file using protoc compiler, so i assume that that references should not give any problem.
I added "grpc\include" , "grpc\src" and "grpc\third_party\protobuf\src\google\protobuf" as include directory.
Interestingly, i'm getting :
error LNK2019: unresolved external symbol "public: __thiscall google::protobuf::internal::LogMessage::LogMessage(enum google::protobuf::LogLevel,char const *,int)" (??0LogMessage#internal#protobuf#google##QAE#W4LogLevel#23#PBDH#Z) referenced in function "int __cdecl google::
error LNK2001: unresolved external symbol "public: virtual bool __thiscall google::protobuf::io::ZeroCopyOutputStream::WriteAliasedRaw(void const *,int)" (?WriteAliasedRaw#ZeroCopyOutputStream#io#protobuf#google##UAE_NPBXH#Z)
error LNK2019: unresolved external symbol "public: bool __thiscall google::protobuf::MessageLite::ParseFromZeroCopyStream(class google::protobuf::io::ZeroCopyInputStream *)" (?ParseFromZeroCopyStream#MessageLite#protobuf#google##QAE_NPAVZeroCopyInputStream#io#23##Z) referenced in function "class grpc::Status __cdecl grpc::GenericDeserialize<class grpc::ProtoBufferReader,class facialpluginpoc::NoParams>(class grpc::ByteBuffer *,class google::protobuf::MessageLite *)" (??$GenericDeserialize#VProtoBufferReader#grpc##VNoParams#facialpluginpoc###grpc##YA?AVStatus#0#PAVByteBuffer#0#PAVMessageLite#protobuf#google###Z)
error LNK2001: unresolved external symbol "class grpc::CoreCodegenInterface * grpc::g_core_codegen_interface" (?g_core_codegen_interface#grpc##3PAVCoreCodegenInterface#1#A)
error LNK2001: unresolved external symbol "class grpc::GrpcLibraryInterface * grpc::g_glip" (?g_glip#grpc##3PAVGrpcLibraryInterface#1#A)
error LNK2019: unresolved external symbol "void __cdecl google::protobuf::internal::VerifyVersion(int,int,char const *)" (?VerifyVersion#internal#protobuf#google##YAXHHPBD#Z) referenced in function "void __cdecl InitDefaultsscc_info_NoParams_facialpluginpoc_2eproto(void)" (?InitDefaultsscc_info_NoParams_facialpluginpoc_2eproto##YAXXZ)
1>facialpluginpoc.pb.obj : error LNK2019: unresolved external symbol "void __cdecl google::protobuf::internal::OnShutdownRun(void (__cdecl*)(void const *),void const *)" (?OnShutdownRun#internal#protobuf#google##YAXP6AXPBX#Z0#Z) referenced in function "void __cdecl google::protobuf::internal::OnShutdownDestroyMessage(void const *)" (?OnShutdownDestroyMessage#internal#protobuf#google##YAXPBX#Z)
1>facialpluginpoc.pb.obj : error LNK2019: unresolved external symbol "private: __int64 __thiscall google::protobuf::io::CodedInputStream::ReadVarint32Fallback(unsigned int)" (?ReadVarint32Fallback#CodedInputStream#io#protobuf#google##AAE_JI#Z) referenced in function "public: bool __thiscall google::protobuf::io::CodedInputStream::ReadVarint32(unsigned int *)" (?ReadVarint32#CodedInputStream#io#protobuf#google##QAE_NPAI#Z)
1>facialpluginpoc.pb.obj : error LNK2019: unresolved external symbol "private: unsigned int __thiscall google::protobuf::io::CodedInputStream::ReadTagFallback(unsigned int)" (?ReadTagFallback#CodedInputStream#io#protobuf#google##AAEII#Z) referenced in function "public: struct std::pair<unsigned int,bool> __thiscall google::protobuf::io::CodedInputStream::ReadTagWithCutoffNoLastTag(unsigned int)" (?ReadTagWithCutoffNoLastTag#CodedInputStream#io#protobuf#google##QAE?AU?$pair#I_N#std##I#Z)
1>facialpluginpoc.pb.obj : error LNK2019: unresolved external symbol "public: static unsigned char * __cdecl google::protobuf::io::CodedOutputStream::WriteStringWithSizeToArray(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,unsigned char *)" (?WriteStringWithSizeToArray#CodedOutputStream#io#protobuf#google##SAPAEABV?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##PAE#Z) referenced in function "public: static unsigned char * __cdecl google::protobuf::internal::WireFormatLite::WriteBytesToArray(int,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,unsigned char *)" (?WriteBytesToArray#WireFormatLite#internal#protobuf#google##SAPAEHABV?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##PAE#Z)
1>facialpluginpoc.pb.obj : error LNK2019: unresolved external symbol "public: void * __thiscall google::protobuf::internal::ArenaImpl::AllocateAligned(unsigned int)" (?AllocateAligned#ArenaImpl#internal#protobuf#google##QAEPAXI#Z) referenced in function "private: void * __thiscall google::protobuf::Arena::AllocateInternal<struct google::protobuf::internal::InternalMetadataWithArenaBase<class google::protobuf::UnknownFieldSet,class google::protobuf::internal::InternalMetadataWithArena>::Container>(bool)" (??$AllocateInternal#UContainer#?$InternalMetadataWithArenaBase#VUnknownFieldSet#protobuf#google##VInternalMetadataWithArena#internal#23##internal#protobuf#google###Arena#protobuf#google##AAEPAX_N#Z)
error LNK2019: unresolved external symbol "public: static bool __cdecl google::protobuf::internal::WireFormatLite::ReadBytes(class google::protobuf::io::CodedInputStream *,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > *)" (?ReadBytes#WireFormatLite#internal#protobuf#google##SA_NPAVCodedInputStream#io#34#PAV?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std###Z) referenced in function "public: virtual bool __thiscall facialpluginpoc::Result::MergePartialFromCodedStream(class google::protobuf::io::CodedInputStream *)" (?MergePartialFromCodedStream#Result#facialpluginpoc##UAE_NPAVCodedInputStream#io#protobuf#google###Z)
I have included all the required header files as project dependency, but still facing this issue.
Is this GRPC library/build/environment issue ? How to resolve this ?

Answer 1

C++ has two stages compiling and linking. From the errors in the post, looks like your includes are good which is not giving any compiler error but all are linker errors. During linking phase, it may be missing "google::protobuf::io" library or lib files.