ProjetUn_.idea_misc.xml

<?xml version="1.0" encoding="UTF-8"?>
<project version="4">
  <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
</project>

ProjetUn_.idea_modules.xml

<?xml version="1.0" encoding="UTF-8"?>
<project version="4">
  <component name="ProjectModuleManager">
    <modules>
      <module fileurl="file://$PROJECT_DIR$/.idea/ProjetUn.iml" filepath="$PROJECT_DIR$/.idea/ProjetUn.iml" />
    </modules>
  </component>
</project>

ProjetUn_.idea_ProjetUn.iml

<?xml version="1.0" encoding="UTF-8"?>
<module classpath="CMake" type="CPP_MODULE" version="4" />

ProjetUn_CMakeLists.txt

cmake_minimum_required(VERSION 3.6)
project(ProjetUn)

set(CMAKE_C_STANDARD 11)

set(SOURCE_FILES main.c)
add_executable(ProjetUn ${SOURCE_FILES})

ProjetUn_main.c

#include <stdio.h>

int main() {
    printf("Hello, World!\n");
    return 0;
}