I have to make a C multi module project in CLion. The project is called a2-dragos12312-a1, and in it I have a "c files" directory containing main.c and ui.c, and a "headers" directory containing ui.h. I made a CMakeLists.txt file in the project directory:

set(CMAKE_BUILD_TYPE Release)
cmake_minimum_required(VERSION 3.10)
project(a2-dragos12312-1)

# Include the headers directory
include_directories(headers, c files)

# Add the source files and create the executable
add_executable(a2-dragos12312-1 "c files/main.c" "c files/ui.c")

However, when I run it I get this error: undefined reference to `ui' collect2.exe: error: ld returned 1 exit status. I tried looking up hot to solve this nut didnt get any good way to fix it.

Tried making a CMakeLists.txt files containing what I said above, but it still doesnt run. If it helps my main.c is

#include "../headers/ui.h"

int main() {
    ui();
    return 0;
}

and my ui.h is

#pragma once

void ui();

In ui.c I do have a void ui() function which works.

I have to make a C multi module project in CLion. The project is called a2-dragos12312-a1, and in it I have a "c files" directory containing main.c and ui.c, and a "headers" directory containing ui.h. I made a CMakeLists.txt file in the project directory:

set(CMAKE_BUILD_TYPE Release)
cmake_minimum_required(VERSION 3.10)
project(a2-dragos12312-1)

# Include the headers directory
include_directories(headers, c files)

# Add the source files and create the executable
add_executable(a2-dragos12312-1 "c files/main.c" "c files/ui.c")

However, when I run it I get this error: undefined reference to `ui' collect2.exe: error: ld returned 1 exit status. I tried looking up hot to solve this nut didnt get any good way to fix it.

Tried making a CMakeLists.txt files containing what I said above, but it still doesnt run. If it helps my main.c is

#include "../headers/ui.h"

int main() {
    ui();
    return 0;
}

and my ui.h is

#pragma once

void ui();

In ui.c I do have a void ui() function which works.

• c
• cmake
• clion
• multi-module

3 Answers 3

You used a comma incorrectly in include_directories(headers, c files). Also, directory names containing spaces (like "c files") often cause problems.

Corrected CMakeLists.txt:

cmake_minimum_required(VERSION 3.10)
project(a2-dragos12312-1 C)
set(CMAKE_BUILD_TYPE Release)
include_directories("headers" "c files")
add_executable(a2-dragos12312-1 "c files/main.c" "c files/ui.c")

Make sure your ui.c file actually contains the definition matching exactly:

#include "..headers/ui.h"

void ui() {
    // implementation
}

Consider renaming "c files" to "src" or "source" to avoid issues caused by spaces.

I found a solution! It is from this thread: https://intellij-support.jetbrains/hc/en-us/community/posts/360010648239-CLion-stopped-recognising-project-as-a-CMake-project. All I had to do was close the project, delete the entire .idea folder and open it again.

Try changeing the order of files in add_executable

add_executable(a2-dragos12312-1  "c files/ui.c" "c files/main.c")