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

Technical requirements

In this chapter, we are going to work with multiple subprojects. One of them – Compiler-RT – needs to be included in your build by us modifying the CMake configuration. Please open the CMakeCache.txt file in your build folder and add the compiler-rt string to the value of the LLVM_ENABLE_PROJECTS variable. Here is an example:

//Semicolon-separated list of projects to build…
LLVM_ENABLE_PROJECTS:STRING="clang;compiler-rt"

After editing the file, launch a build with any build target. CMake will try to reconfigure itself.

Once everything has been set up, we can build the components we need for this chapter. Here is an example command:

$ ninja clang compiler-rt opt llvm-profdata

This will build the clang tool we're all familiar with and a collection of Compiler-RT libraries, which we are going to introduce shortly.

You can find the sample code for this chapter in the same GitHub repository: https://github.com...