CODEWITHSUNDEEP
c++gccprotocol-buffers
supersuraccoon
supersuraccoon

Reputation: 1691

gcc header file not found with google protocol buffer

I'm trying to use the gcc command to compile and run a .cpp file to test google protobuf.

CPP_TEST.cpp

#include "GameInfo.pb.h"

int main() {
   // ...
}

GameInfo.pb.h generated by protoc

#ifndef PROTOBUF_GameInfo_2eproto__INCLUDED
#define PROTOBUF_GameInfo_2eproto__INCLUDED

#include <string>

#include <google/protobuf/stubs/common.h>
// ...

and my files in folder looks like this

- test
    CPP_TEST.cpp
    GameInfo.pb.h
    GameInfo.pb.cc

    // the lib file for protobuf
    libprotobuf.a

    // the srouce code of protobuf
    - google
        - protobuf
            // ...
            - stubs
                common.h
                // ...

and then I tried to compile the .cpp file

gcc CPP_TEST.cpp -l ./google -o OUT_CPP_TEST

But get the error:

#include <google/protobuf/stubs/common.h>
'google/protobuf/stubs/common.h' file not found with <angled> include; use "quotes" instead

I think it is an error with the gcc compiler flag but can not figure out why...

Any advice will be appreciated, thanks :)

UPDATE:

After changing the command to

gcc CPP_TEST.cpp -I./ -o OUT_CPP_TEST

The file is ok to compiler and run.

But if I add a code to the main function :

game::info::GameInfo gameInfoOut;

And compiler it will fail with:

Undefined symbols for architecture x86_64:
  "game::info::GameInfo::GameInfo()", referenced from:
      _main in CPP_TEST-9245ef.o
  "game::info::GameInfo::~GameInfo()", referenced from:
      _main in CPP_TEST-9245ef.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

So I tried to add the libprotobuf.a file to gcc command

gcc CPP_TEST.cpp -L./ -lprotobuf -I./ -o CPP_TEST_OUT

But I am still getting the same error:

Undefined symbols for architecture x86_64:
  "game::info::GameInfo::GameInfo()", referenced from:
      _main in CPP_TEST-0e3576.o
  "game::info::GameInfo::~GameInfo()", referenced from:
      _main in CPP_TEST-0e3576.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

UPDATE:

I tried to complier and link all the files step by step like:

gcc -c -I./ GameInfo.pb.cc 
gcc -c -I./ GameEnum.pb.cc 
gcc -c -I./ CPP_TEST.cpp

and link

gcc CPP_TEST.o GameInfo.pb.o GameEnum.pb.o -L./ -lprotobuf -o main

And now I am getting bunch of errors like:

Undefined symbols for architecture x86_64:
  "___dynamic_cast", referenced from:
      game::info::RoleInfo const* google::protobuf::internal::dynamic_cast_if_available<game::info::RoleInfo const*, google::protobuf::Message const*>(google::protobuf::Message const*) in GameInfo.pb.o
      game::info::ItemInfo const* google::protobuf::internal::dynamic_cast_if_available<game::info::ItemInfo const*, google::protobuf::Message const*>(google::protobuf::Message const*) in GameInfo.pb.o
      game::info::GameInfo const* google::protobuf::internal::dynamic_cast_if_available<game::info::GameInfo const*, google::protobuf::Message const*>(google::protobuf::Message const*) in GameInfo.pb.o
      google::protobuf::FileDescriptorSet const* google::protobuf::internal::dynamic_cast_if_available<google::protobuf::FileDescriptorSet const*, google::protobuf::Message const*>(google::protobuf::Message const*) in libprotobuf.a(descriptor.pb.o)
      google::protobuf::FileDescriptorProto const* google::protobuf::internal::dynamic_cast_if_available<google::protobuf::FileDescriptorProto const*, google::protobuf::Message const*>(google::protobuf::Message const*) in libprotobuf.a(descriptor.pb.o)
      google::protobuf::DescriptorProto_ExtensionRange const* google::protobuf::internal::dynamic_cast_if_available<google::protobuf::DescriptorProto_ExtensionRange const*, google::protobuf::Message const*>(google::protobuf::Message const*) in libprotobuf.a(descriptor.pb.o)
      google::protobuf::DescriptorProto const* google::protobuf::internal::dynamic_cast_if_available<google::protobuf::DescriptorProto const*, google::protobuf::Message const*>(google::protobuf::Message const*) in libprotobuf.a(descriptor.pb.o)
      ...
  "___gxx_personality_v0", referenced from:
      game::enumeration::protobuf_AssignDesc_GameEnum_2eproto() in GameEnum.pb.o
      google::protobuf::GoogleOnceInit(long*, void (*)()) in GameEnum.pb.o
      Dwarf Exception Unwind Info (__eh_frame) in GameEnum.pb.o
      game::info::protobuf_AssignDesc_GameInfo_2eproto() in GameInfo.pb.o
      game::info::protobuf_AddDesc_GameInfo_2eproto() in GameInfo.pb.o
      game::info::RoleInfo::RoleInfo() in GameInfo.pb.o
      game::info::RoleInfo::RoleInfo(game::info::RoleInfo const&) in GameInfo.pb.o
      // more here

It is really weird since the I can complier and run it successfully in the xcode with all the GameInfo.pb.h/cc GameEnum.pb.h/cc, libprotobuf.a and "google source".

Upvotes: 0

Views: 2714

Answers (1)

jblixr
jblixr

Reputation: 1395

gcc doesn't know the include directory of google headers until you mention the path using -I flag not -l. As google directory is in the current working directory so no need to pass ./google for -I.

g++ -I./ CPP_TEST.cpp -o OUT_CPP_TEST

or else you can just use what your error suggestion said (use quotes instead of angles) because your file hierarchy matches this suggestion.

#include "google/protobuf/stubs/common.h"

Upvotes: 1

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