Book Image

Learn LLVM 12

By : Kai Nacke
Book Image

Learn LLVM 12

By: Kai Nacke

Overview of this book

LLVM was built to bridge the gap between compiler textbooks and actual compiler development. It provides a modular codebase and advanced tools which help developers to build compilers easily. This book provides a practical introduction to LLVM, gradually helping you navigate through complex scenarios with ease when it comes to building and working with compilers. You’ll start by configuring, building, and installing LLVM libraries, tools, and external projects. Next, the book will introduce you to LLVM design and how it works in practice during each LLVM compiler stage: frontend, optimizer, and backend. Using a subset of a real programming language as an example, you will then learn how to develop a frontend and generate LLVM IR, hand it over to the optimization pipeline, and generate machine code from it. Later chapters will show you how to extend LLVM with a new pass and how instruction selection in LLVM works. You’ll also focus on Just-in-Time compilation issues and the current state of JIT-compilation support that LLVM provides, before finally going on to understand how to develop a new backend for LLVM. By the end of this LLVM book, you will have gained real-world experience in working with the LLVM compiler development framework with the help of hands-on examples and source code snippets.
Table of Contents (17 chapters)
Section 1 – The Basics of Compiler Construction with LLVM
Section 2 – From Source to Machine Code Generation
Section 3 –Taking LLVM to the Next Level

Chapter 6: IR Generation for High-Level Language Constructs

High-level languages today usually make use of aggregate data types and object-oriented programming (OOP) constructs. LLVM IR has some support for aggregate data types, and we must implement OOP constructs such as classes on our own. Adding aggregate types gives rise to the question of how parameters of an aggregate type are passed. Different platforms have different rules, and this is also reflected in the IR. Being compliant with the calling convention ensures that system functions can be called.

In this chapter, you will learn how to translate aggregate data types and pointers to LLVM IR, and how to pass parameters to a function in a system-compliant way. You'll also learn how to implement classes and virtual functions in LLVM IR.

This chapter will cover the following topics:

  • Working with arrays, structs, and pointers
  • Getting the application binary interface right
  • Creating IR code for classes...