Chapter 1: First Steps with CMake

There is something magical about turning source code into a working application. It is not only the effect itself, that is, a working mechanism that we devise and bring to life, but the very process or act of exercising the idea into existence.

As programmers, we work in the following loop: design, code, and test. We invent changes, we phrase them in a language that the compiler understands, and we check whether they work as intended. To create a proper, high-quality application from our source code, we need to meticulously execute repetitive, error-prone tasks: invoking the correct commands, checking the syntax, linking binary files, running tests, reporting issues, and more.

It takes great effort to remember each step every single time. Instead, we want to stay focused on the actual coding and delegate everything else to automated tooling. Ideally, this process would start with a single button, right after we have changed our code. It would be smart, fast, extensible, and work in the same way across different OSs and environments. It would be supported by multiple Integrated Development Environments (IDEs) but also by Continuous Integration (CI) pipelines that test our software after a change is submitted to a shared repository.

CMake is the answer to many such needs; however, it requires a bit of work to configure and use correctly. This is not because CMake is unnecessarily complex but because the subject that we're dealing with here is. Don't worry. We'll undergo this whole learning process very methodically; before you know it, you will have become a building guru.

I know you're eager to rush off to start writing your own CMake projects, and I applaud your attitude. Since your projects will be primarily for users (yourself included), it's important for you to understand that perspective as well.

So, let's start with just that: becoming a CMake power user. We'll go through a few basics: what this tool is, how it works in principle, and how to install it. Then, we'll do a deep dive on the command line and modes of operation. Finally, we'll wrap up with the purposes of different files in a project, and we'll explain how to use CMake without creating a project at all.

In this chapter, we're going to cover the following main topics:

• Understanding the basics
• Installing CMake on different platforms
• Mastering the command line
• Navigating the project files
• Discovering scripts and modules