Question

我正在尝试在ROS Indigo中使用Protocol Buffers。似乎在连接CPP源代码时存在问题。在编译时，它会抛出以下错误：

Linking CXX executable /home/ravi/ros_ws/devel/lib/protobuf_ros_tutorial/add_person
CMakeFiles/add_person.dir/src/add_person.cc.o: In function `PromptForAddress(tutorial::Person*)':
add_person.cc:(.text+0x6a): undefined reference to `google::protobuf::internal::fixed_address_empty_string'
add_person.cc:(.text+0x1a5): undefined reference to `google::protobuf::internal::ArenaImpl::AllocateAlignedAndAddCleanup(unsigned long, void (*)(void*))'
add_person.cc:(.text+0x1cc): undefined reference to `google::protobuf::internal::fixed_address_empty_string'
add_person.cc:(.text+0x322): undefined reference to `google::protobuf::internal::fixed_address_empty_string'
add_person.cc:(.text+0x454): undefined reference to `google::protobuf::util::TimeUtil::SecondsToTimestamp(long)'
add_person.cc:(.text+0x496): undefined reference to `google::protobuf::Timestamp::CopyFrom(google::protobuf::Timestamp const&)'
add_person.cc:(.text+0x49e): undefined reference to `google::protobuf::Timestamp::~Timestamp()'
add_person.cc:(.text+0x52c): undefined reference to `google::protobuf::internal::fixed_address_empty_string'

以下是CMakeLists.txt

cmake_minimum_required(VERSION 2.8.3)
project(protobuf_ros_tutorial)

set(CMAKE_CXX_FLAGS "-std=c++11  ${CMAKE_CXX_FLAGS}")

find_package(catkin REQUIRED COMPONENTS
  roscpp
)

find_package(Protobuf REQUIRED)

catkin_package(
)

include_directories(
  include
  ${catkin_INCLUDE_DIRS}
  ${PROTOBUF_INCLUDE_DIRS}
)

add_library(addressbook_protobuf include/addressbook.pb.cc)

add_executable(add_person src/add_person.cc)

target_link_libraries(
    add_person 
    ${catkin_LIBRARIES}
    addressbook_protobuf
    ${PROTOBUF_LIBRARIES}
)

package.xml的默认内容如下：

<?xml version="1.0"?>
<package format="2">
  <name>protobuf_ros_tutorial</name>
  <version>0.0.0</version>
  <description>The protobuf_ros_tutorial package</description>

  <maintainer email="ravi@todo.todo">ravi</maintainer>
  <license>TODO</license>
  <buildtool_depend>catkin</buildtool_depend>
  <build_depend>roscpp</build_depend>
  <build_export_depend>roscpp</build_export_depend>
  <exec_depend>roscpp</exec_depend>

  <export>
  </export>
</package>

以下是ROS包的文件结构：

ravi@lab:~/ros_ws/src/protobuf_ros_tutorial$ ls -R
.:
CMakeLists.txt  include  package.xml  src

./include:
addressbook.pb.cc  addressbook.pb.h  addressbook.proto

./src:
add_person.cc

我怀疑CMakeLists.txt文件。我错过了什么吗？

Answer 1

Protobuf版本不匹配。我从源代码安装了Protobuf 3。但是，ROS Indigo内部使用的是Protobuf 2.

作为解决方法，我删除了Protobuf 3，然后在本地安装了我的项目。

未定义参考ROS CPP中的google :: protobuf

1 个答案: