Clion undefined reference to function [duplicate] - c++

Question

This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 5 years ago.
I have a simple program with my main.cpp, a header file func.h and another source file func.cpp. I use CLion 2016.3. My compiler is gcc.
They look like this:
Main.cpp
#include <iostream>
#include <stdlib.h>
#include <cstdio>
#include "func.h"
int main() {
int c;
c = number(2);
printf("%i", c);
}
func.cpp
int number(int a){
return a;
}
func.h
#ifndef TEST2_FUNC_H
#define TEST2_FUNC_H
int number(int a);
#endif //TEST2_FUNC_H
My cmakelists.txt
cmake_minimum_required(VERSION 3.6)
project(test2)
set(CMAKE_CXX_STANDARD 11)
set(SOURCE_FILES main.cpp)
add_executable(test2 ${SOURCE_FILES})
If i run the build i get the following error:
CMakeFiles\test2.dir/objects.a(main.cpp.obj): In function `main':
C:/Users/name/ClionProjects/test2/main.cpp:8: undefined reference to `number(int)'
....
How can i fix this? I've searched for other similar issues and found some solutions but they didn't work for me or i didn't know what to do. Actually I have this problem with a C-Project but the issue is the same and I think the solution will be the same.
Can you please help me?
Thank you very much.

Answer 1

Make sure you include func.h in your main
#include "func.h"
and put 'func.cpp' in CMakeList.txt set source
List the sources explicitly here. That is all (.cpp, .c ,.cc) to compile together. If the sources files are not in the current directory, then you have to specify the full path to the source files
set(SOURCE_FILES main.cpp func.cpp)
You can use file(GLOB SOURCE_FILES *.cpp) if you want to automatically add files in your compilation. But keep in mind that this "trick" is strongly not encouraged to do.