Introduction

In C++, compilation is the process by which source code is transformed into machine code and organized in object files that are then linked together to produce an executable. The compiler actually works on a single file at a time, produced by the preprocessor from a single source file and all the header files that it includes. This is, however, an oversimplification of what happens when we compile the code. This chapter addresses topics related to preprocessing and compilation, with a focus on various methods to perform conditional compilation, but also touching other modern topics such as using attributes for providing implementation-defined language extensions.