In this chapter, we presented you with a historical perspective of the design decisions used in the LLVM project and gave you an overview of the most important ones. We also showed you how to use the LLVM components in two different ways. First, by using the compiler driver, which is a high-level tool that performs the entire compilation for you in a single command. Second, by using separate LLVM standalone tools. Besides storing intermediary results on the disk, which slows down compilation, the tools allow us to interface with specific fragments of the LLVM libraries via the command line, giving us finer control over the compilation process. They are an excellent way to learn how LLVM works. We also showed you a few of the C++ coding styles used in LLVM and explained how you should face the LLVM code documentation and use the community to ask for help.

In the next chapter, we will present details about the Clang frontend implementation and its libraries.