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

Exercises

Here are some simple questions and exercises that you might want to play around with by yourself:

  1. Though most of the time Tokens are harvested from provided source code, in some cases, Tokens might be generated dynamically inside the Preprocessor. For example, the __LINE__ built-in macro is expanded to the current line number, and the __DATE__ macro is expanded to the current calendar date. How does Clang put that generated textual content into the source code buffer of SourceManager? How does Clang assign SourceLocation to these tokens?
  2. When we were talking about implementing a custom PragmaHandler, we were leveraging Preprocessor::Lex to fetch Tokens followed after the pragma name, until we hit the eod token kind. Can we keep lexing beyond the eod token? What interesting things will you do if you can consume arbitrary tokens after the #pragma directive?
  3. In the macro guard project from the Developing custom preprocessor plugins and callbacks section, the...