Book Image

LLVM Techniques, Tips, and Best Practices Clang and Middle-End Libraries

By : Min-Yih Hsu
Book Image

LLVM Techniques, Tips, and Best Practices Clang and Middle-End Libraries

By: Min-Yih Hsu

Overview of this book

Every programmer or engineer, at some point in their career, works with compilers to optimize their applications. Compilers convert a high-level programming language into low-level machine-executable code. LLVM provides the infrastructure, reusable libraries, and tools needed for developers to build their own compilers. With LLVM’s extensive set of tooling, you can effectively generate code for different backends as well as optimize them. In this book, you’ll explore the LLVM compiler infrastructure and understand how to use it to solve different problems. You’ll start by looking at the structure and design philosophy of important components of LLVM and gradually move on to using Clang libraries to build tools that help you analyze high-level source code. As you advance, the book will show you how to process LLVM IR – a powerful way to transform and optimize the source program for various purposes. Equipped with this knowledge, you’ll be able to leverage LLVM and Clang to create a wide range of useful programming language tools, including compilers, interpreters, IDEs, and source code analyzers. By the end of this LLVM book, you’ll have developed the skills to create powerful tools using the LLVM framework to overcome different real-world challenges.
Table of Contents (18 chapters)
1
Section 1: Build System and LLVM-Specific Tooling
6
Section 2: Frontend Development
11
Section 3: "Middle-End" Development

Working with SourceLocation and SourceManager

When working closely with source files, one of the most fundamental questions is how a compiler frontend would be able to locate a piece of string in the file. On one hand, printing format messages well (compilation error and warning messages, for example) is a crucial job, in which accurate line and column numbers must be displayed. On the other hand, the frontend might need to manage multiple files at a time and access their in-memory content in an efficient way. In Clang, these questions are primarily handled by two classes: SourceLocation and SourceManager. We're going to give you a brief introduction to them and show how to use them in practice in the rest of this section.

Introducing SourceLocation

The SourceLocation class is used for representing the location of a piece of code in its file. When it comes to its implementation, using line and column numbers is probably the most intuitive way to do this. However, things...