Building C++ application on Ubuntu with CMake, make and VSCode

Wednesday 19 February 2020

Building C++ application on Ubuntu with CMake, make and VSCode

This article shows how to set up building C++ project with CMake and make in VSCode on Ubuntu.

First make sure cmake and make are installed:

$ cmake --version
cmake version 3.10.2
CMake suite maintained and supported by Kitware (kitware.com/cmake).

$ make --version
GNU Make 4.1
Built for x86_64-pc-linux-gnu
Copyright (C) 1988-2014 Free Software Foundation, Inc.
Licence GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Let's assume we have a C++ project with following structure:

build/
src/main.cpp
CMakeLists.txt

build is an empty directory; this is where the build output will be located.

src/main.cpp:

#include <iostream>

int main() {
std::cout << "main()" << std::endl;
return 0;
}

CMakeLists.txt:

cmake_minimum_required(VERSION 3.0)
project(cmake-demo)
set(SOURCE src/main.cpp)
add_executable(${PROJECT_NAME} ${SOURCE})

In VSCode, press CTRL+SHIFT+P or go to View >> Command Palette, select Tasks: Configure Default Build Task and then Create tasks.json file from template and then Other.

VSCode - Command Palette

This will create ./.vscode/tasks.json with a sample task:

{
// See https://go.microsoft.com/fwlink/?LinkId=733558
// for the documentation about the tasks.json format
"version": "2.0.0",
"tasks": [
{
"label": "echo",
"type": "shell",
"command": "echo Hello"
},
}

We can replace it with cmake and make toolchain:

{
// See https://go.microsoft.com/fwlink/?LinkId=733558
// for the documentation about the tasks.json format
"version": "2.0.0",
"tasks": [
{
"type": "shell",
"label": "CMake && make",
"options": {
"cwd": "${workspaceFolder}/build"
},
"command": "cmake make -DCMAKE_BUILD_TYPE=Debug .. && make -j 4",
"group": {
"kind": "build",
"isDefault": true
}
}
]
}

To build a project press CTRL+SHIFT+B or go to Terminal >> Run Build Task.

We'd get the output like this:

> Executing task: cmake make -DCMAKE_BUILD_TYPE=Debug .. && make -j 4 <

-- Configuring done
-- Generating done
-- Build files have been written to: /home/xxxxxxx/xx/xxx/cmake-demo/build
Scanning dependencies of target cmake-demo
[ 50%] Building CXX object CMakeFiles/cmake-demo.dir/src/main.cpp.o
[100%] Linking CXX executable cmake-demo
[100%] Built target cmake-demo

Terminal will be reused by tasks, press any key to close it.

To run the executable (build output):

$ ./build/cmake-demo
main()