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

The core of LIT is written in Python, so please make sure you have Python 2.7 or Python 3.x installed (Python 3.x is preferable, as LLVM is gradually retiring Python 2.7 now).

In addition, there are a bunch of supporting utilities, such as FileCheck, which will be used later. To build those utilities, the fastest way, unfortunately, is to build any of the check-XXX (phony) targets. For example, we could build check-llvm-support, as shown in the following code:

$ ninja check-llvm-support

Finally, the last section requires that llvm-test-suite has been built, which is a separate repository from llvm-project. We can clone it by using the following command:

$ git clone https://github.com/llvm/llvm-test-suite

The easiest way to configure the build will be using one of the cached CMake configs. For example, to build the test suite with optimizations (O3), we will use the following code:

$ mkdir .O3_build
$ cd .O3_build
$ cmake -G Ninja -DCMAKE_C_COMPILER...