Issue
I am trying to build my Project using cmake. With 3rd Party headerfiles and libarys. The headers are in /usr/local/include/ and the libary in /usr/local/lib/. And I think the compiler finds the files because I get no error on the includes but when I try to compile it it doesn´t find the functions I´m calling.
/mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:12: undefined reference to `ola::InitLogging(ola::log_level, ola::log_output)'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:13: undefined reference to `ola::DmxBuffer::DmxBuffer()'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:14: undefined reference to `ola::DmxBuffer::Blackout()'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:17: undefined reference to `ola::client::StreamingClient::StreamingClient(ola::client::StreamingClient::Options const&)'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:19: undefined reference to `ola::client::StreamingClient::Setup()'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:26: undefined reference to `ola::DmxBuffer::SetChannel(unsigned int, unsigned char)'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:27: undefined reference to `ola::client::StreamingClient::SendDmx(unsigned int, ola::DmxBuffer const&)'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:34: undefined reference to `ola::client::StreamingClient::~StreamingClient()'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:34: undefined reference to `ola::DmxBuffer::~DmxBuffer()'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:34: undefined reference to `ola::client::StreamingClient::~StreamingClient()'
/usr/bin/ld: /mnt/c/Users/Max/CLionProjects/Lightning_Controller/main.cpp:34: undefined reference to `ola::DmxBuffer::~DmxBuffer()'
collect2: error: ld returned 1 exit status
If I compile it with G++ and this parameters g++ main.cpp -lola -lolacommon -lprotobuf it works.
I tried to use the Option Mentioned in this Post but it didn´t change anything.
My Question is how do i translate this from g++ to cmake ?
Solution
It would be nice to have more information about what you are doing, but this is what I have for you.
The compiler can't find the implementation for the functions you're calling. It finds the headers, but it doesn't link the library with the actual implementations. With CMake, specify the libraries to link.
I don't know what version of C++ you are on, so change it accordingly.
cmake_minimum_required(VERSION 3.10)
project(Lightning_Controller)
set(CMAKE_CXX_STANDARD 14)
include_directories(/usr/local/include/)
add_executable(Lightning_Controller main.cpp)
link_directories(/usr/local/lib/)
target_link_libraries(Lightning_Controller ola olacommon protobuf)
Answered By - Ben A. Answer Checked By - Clifford M. (WPSolving Volunteer)