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

Exploring the TestSuite framework

In the previous sections, we learned how regression tests were performed in LLVM. More specifically, we looked at the ShTest testing format (recalling the config.test_format = lit.formats.ShTest(…) line), which basically runs end-to-end tests in a shell script fashion. The ShTest format provides more flexibility when it comes to validating results since it can use the FileCheck tool we introduced in the previous section, for example.

This section is going to introduce another kind of testing format: TestSuite. The TestSuite format is part of the llvm-test-suite project – a collection of test suites and benchmarks created for testing and benchmarking LLVM. Similar to ShTest, this LIT format is also designed to run end-to-end tests. However, TestSuite aims to make developers' lives easier when they want to integrate existing executable-based test suites or benchmark codebases. For example, if you want to use the famous SPEC benchmark...