CMakeFiles/

cmake_minimum_required (VERSION 3.10)

project(cmake-tutorial)

add_library(math src/math.cc)

add_executable(cmake-tutorial src/main.cc)

target_link_libraries(cmake-tutorial math)

This tutorial contains step-by-step how to setup CMake on your

C++ project.

First of all, you need to install `cmake`.

On Ubuntu:

sudo apt-get install cmake

On macOS:

brew install cmake

Make sure the `cmake` is installed correctly:

% cmake --version

cmake version 3.10.2

CMake suite maintained and supported by Kitware (kitware.com/cmake).

We can build this project using the following command:

c++ src/main.cc src/math.cc -o cmake-tutorial

Or we can do the compile and linking on the separate steps

c++ -c src/math.cc -o math.o

c++ src/main.cc math.o -o cmake-tutorial

We can automate the step to compile and link above using `Makefile`.

First we need to write a `Makefile` with the following content:

math.o: src/math.cc src/math.h

c++ -c src/math.cc -o math.o

cmake-tutorial: math.o

c++ src/main.cc math.o -o cmake-tutorial

build: cmake-tutorial

Now we can run:

make build

to build `cmake-tutorial` binary. If there are no changes in `src/{main,math}.c` and

`src/math.h`, the subsequent command will do nothing:

% make build

make: Nothing to be done for `build'.

this is usefull when working on larger project, we only compile the object that changes.

Now we know how to perform compiling and linking using the `C++` and

`make` command. Now we can use `cmake` to do all of this for us.

Create new `CMakeLists.txt` with the following content:

cmake_minimum_required (VERSION 3.10)

# Define the project

project(cmake-tutorial)

# Add definition for math library

add_library(math src/math.cc)

# Add definition for the cmake-tutorial binary

add_executable(cmake-tutorial src/main.cc)

target_link_libraries(cmake-tutorial math)

We can generate the `Makefile` based on the definition above using the following

command:

cmake .

Now we can run `make cmake-tutorial` to build the binary.

% make cmake-tutorial

Scanning dependencies of target math

[ 25%] Building CXX object CMakeFiles/math.dir/src/math.cc.o

[ 50%] Linking CXX static library libmath.a

[ 50%] Built target math

Scanning dependencies of target cmake-tutorial

[ 75%] Building CXX object CMakeFiles/cmake-tutorial.dir/src/main.cc.o

[100%] Linking CXX executable cmake-tutorial

[100%] Built target cmake-tutorial

#include <iostream>

#include "math.h"

using namespace std;

int main(int argc, char **argv) {

int result = math::add(1, 2);

cout << "result : " << result << endl;

}

namespace math {

int add(int a, int b) {

return a + b;

}

}

#ifndef CMAKE_TUTORIAL_MATH_H

#define CMAKE_TUTORIAL_MATH_H

namespace math {

int add(int a, int b);

}

#endif