Book Image

Learn LLVM 17 - Second Edition

By : Kai Nacke, Amy Kwan
Book Image

Learn LLVM 17 - Second Edition

By: Kai Nacke, Amy Kwan

Overview of this book

LLVM was built to bridge the gap between the theoretical knowledge found in compiler textbooks and the practical demands of compiler development. With a modular codebase and advanced tools, LLVM empowers developers to build compilers with ease. This book serves as a practical introduction to LLVM, guiding you progressively through complex scenarios and ensuring that you navigate the challenges of building and working with compilers like a pro. The book starts by showing you how to configure, build, and install LLVM libraries, tools, and external projects. You’ll then be introduced to LLVM's design, unraveling its applications in each compiler stage: frontend, optimizer, and backend. Using a real programming language subset, you'll build a frontend, generate LLVM IR, optimize it through the pipeline, and generate machine code. Advanced chapters extend your expertise, covering topics such as extending LLVM with a new pass, using LLVM tools for debugging, and enhancing the quality of your code. You'll also focus on just-in-time compilation issues and the current state of JIT-compilation support with LLVM. Finally, you’ll develop a new backend for LLVM, gaining insights into target description and how instruction selection works. By the end of this book, you'll have hands-on experience with the LLVM compiler development framework through real-world examples and source code snippets.
Table of Contents (20 chapters)
1
Part 1: The Basics of Compiler Construction with LLVM
4
Part 2: From Source to Machine Code Generation
10
Part 3: Taking LLVM to the Next Level
14
Part 4: Roll Your Own Backend

Preface

Constructing a compiler is a complex and fascinating task. The LLVM project provides reusable components for your compiler and the LLVM core libraries implement a world-class optimizing code generator, which translates a source language-independent intermediate representation of machine code for all popular CPU architectures. The compilers for many programming languages already take advantage of LLVM technology.

This book teaches you how to implement your own compiler and how to use LLVM to achieve it. You will learn how the frontend of a compiler turns source code into an abstract syntax tree, and how to generate Intermediate Representation (IR) from it. Furthermore, you will also explore adding an optimization pipeline to your compiler, which allows you to compile the IR to performant machine code.

The LLVM framework can be extended in several ways, and you will learn how to add new passes, and even a completely new backend to LLVM. Advanced topics such as compiling for a different CPU architecture and extending clang and the clang static analyzer with your own plugins and checkers are also covered. This book follows a practical approach and is packed with example source code, which makes it easy to apply the gained knowledge within your own projects.