undefined reference to `Json::Value::Value(Json::ValueType)'

[FatmanurKucukayvaz]

I use clion. I want to use json library. But i have soo many problems. Firstly undefined reference to `Json::Value::Value(Json::ValueType)'. How can i solve this problem.

[ya1gaurav]

It means you are not linking to libjsoncpp correctly. Can u paste 'make V=1' output.

[fawdlstty]

I've had this problem, too. output like this, thx

g++ -std=c++11 -g -DDEBUG -I /usr/include -c *.cpp
g++ -std=c++11 -g -DDEBUG -I /usr/include -o MerchantServer main.o -L /usr/lib64 -lstdc++ -lm -ldl -lpthread -lcrypto -lcurl -liconv -lbsoncxx -lmongocxx -ljsoncpp -ljson
main.o: In function `obj_merchant::get_root()':
/root/project_ms/obj_merchant.hpp:61: undefined reference to `Json::Value::operator=(Json::Value)'
/root/project_ms/obj_merchant.hpp:64: undefined reference to `Json::Value::operator=(Json::Value)'
/root/project_ms/obj_merchant.hpp:68: undefined reference to `Json::Value::append(Json::Value&&)'
/root/project_ms/obj_merchant.hpp:69: undefined reference to `Json::Value::append(Json::Value&&)'
main.o: In function `request_process::do_request(std::map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >)':
/root/project_ms/request_process.hpp:66: undefined reference to `Json::Value::operator=(Json::Value)'
/root/project_ms/request_process.hpp:127: undefined reference to `Json::Value::append(Json::Value&&)'
/root/project_ms/request_process.hpp:128: undefined reference to `Json::Value::append(Json::Value&&)'
/root/project_ms/request_process.hpp:156: undefined reference to `Json::Value::operator=(Json::Value)'
/root/project_ms/request_process.hpp:160: undefined reference to `Json::StreamWriterBuilder::operator[](std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
/root/project_ms/request_process.hpp:160: undefined reference to `Json::Value::operator=(Json::Value)'
/root/project_ms/request_process.hpp:161: undefined reference to `Json::StreamWriterBuilder::operator[](std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
/root/project_ms/request_process.hpp:161: undefined reference to `Json::Value::operator=(Json::Value)'
/root/project_ms/request_process.hpp:162: undefined reference to `Json::writeString[abi:cxx11](Json::StreamWriter::Factory const&, Json::Value const&)'
collect2: error: ld returned 1 exit status
make: *** [MerchantServer] Error 1

[cdunn2001]

@fawdlstty, you have jsoncpp compiled with a different C++ ABI than you link against. The easiest solution is to use exactly the same compiler-version to build both library and executable.

[fawdlstty]

i want use gcc-7.3.0 to compile, and i use ln "/usr/bin/gcc" and "/usr/bin/g++" to new version, but the cmake still use the old version gcc-4.8.5 to compile, can you fixed it?thx

[fawdlstty]

@cdunn2001

[cdunn2001]

If there is a problem with the CMakefiles, please submit a fix. We rely on users for that.

We use Meson instead of Cmake for our continuous builds, and that is what I recommend.

[fawdlstty]

i don't know cmakefile,, and i used the meson, it's still use the old gcc version :-(

meson --buildtype ${BUILD_TYPE} --default-library ${LIB_TYPE} . build-${LIB_TYPE}

The Meson build system
Version: 0.44.1
Source dir: /root/lib/jsoncpp-1.8.4
Build dir: /root/lib/jsoncpp-1.8.4/build-shared
Build type: native build
Project name: jsoncpp
Native C++ compiler: c++ (gcc 4.8.5)
Build machine cpu family: x86_64
Build machine cpu: x86_64
Configuring version.h using configuration
Build targets in project: 3
Found ninja-1.7.2 at /usr/bin/ninja-build

/usr/bin/gcc -v

Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
COLLECT_LTO_WRAPPER=/home/root/gcc-7.3.0/libexec/gcc/x86_64-pc-linux-gnu/7.3.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --prefix=/home/root/gcc-7.3.0 --enable-languages=c,c++,fortran --disable-multilib
Thread model: posix
gcc version 7.3.0 (GCC)

[coleged]

I am banging into same exact problem. I have jsoncpp linked code that compiles and runs on OSx with library installed via homebrew. In trying to compile the code on Ubuntu I run into undefined reference errors on what looks to be every Json symbol in the objects. I have tried the ubuntu release compiled lib and also compiled the lib from git repo. Exact same issues.

The apple stuff works with clang in xcode and with make / g++, but I cant get the objects to link at all with Ubuntu and have now exhausted my expertise.

[fawdlstty]

@coleged 这个问题我解决了，主要是因为，linux系统默认安装的低版本gcc，然后手工安装了高版本gcc所致。通过设置软连接，直接运行gcc命令看起来是运行的高版本，实际上，系统默认的依旧是低版本。我的解决方法是，centos下使用了devtoolset-7，然后切换到devtools环境。ubuntu下应该差不多的。

[coleged]

Thanks for the suggestion. My g++ was already 7.x, so I did a clean build of 8.2.0, and rebuilt jsoncpp. However, it didn't bode well to see that the libjsoncpp.a file differed from the one built using g++7 by just one byte. Needless to say, exactly the same failure to find any symbols. ......

$ make
g++ -std=c++17 -L. -ljsoncpp -c neohub.cpp -o neohub.o
g++ -std=c++17 -L. -ljsoncpp -c main.cpp -o main.o
g++ -std=c++17 -L. -ljsoncpp -c functions.cpp -o functions.o
g++ -L. -ljsoncpp neohub.o main.o functions.o
-o nprobe
neohub.o: In function Neohub::init()': neohub.cpp:(.text+0xb2): undefined reference to Json::Value::Value(Json::ValueType)'
neohub.cpp:(.text+0x125): undefined reference to Json::Value::operator=(Json::Value)' neohub.cpp:(.text+0x134): undefined reference to Json::Value::~Value()'
neohub.cpp:(.text+0x148): undefined reference to Json::Value::Value(Json::ValueType)' neohub.cpp:(.text+0x17a): undefined reference to Json::Value::operator[](char const*)'
neohub.cpp:(.text+0x194): undefined reference to Json::Value::begin()' neohub.cpp:(.text+0x1aa): undefined reference to Json::Value::end()'

etc. etc.

[fawdlstty]

在这个仓库的issue里面说这个可能比较拆台，在这里给作者赔个不是。。。我建议你，玩玩nlohmann的json，一个头文件，直接引入就好，没有任何其他负担

[coleged]

Thanks - I'll look into Niohmann; I was beginning to think jsoncpp looked a bit rusty. It will probably take less time to migrate than it took to compile gcc ;-)