Summary

This chapter opened the door to actual programming with CMake – you're now able to write great, informative comments and invoke built-in commands, and you understand how to correctly provide all kinds of arguments to them. This knowledge alone will help you understand the unusual syntax of CMake listfiles that you may have seen in other projects.

Next, we covered variables in CMake – specifically, how to reference, set, and unset normal, cache, and environment variables. We took a deep dive into how directory and function scopes work, and we discussed the issues (and their workarounds) relating to nested scopes.

We also covered lists and control structures. We discussed the syntax of conditions, their logical operations, the evaluation of unquoted arguments, and strings and variables. We learned how to compare values, do simple checks, and examine the state of the files in the system. This allows us to write conditional blocks and while loops. And...