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

Adding a custom toolchain

In the previous section, we learned how to add custom flags for the driver in Clang and learned how the driver translated them into flags that are accepted by the frontend. In this section, we are going to talk about the toolchain – an important module inside the driver that helps it adapt to different platforms.

Recall that in the first section of this chapter, Understanding drivers and toolchains in Clang, we showed the relationships between driver and toolchains in Figure 8.1: the driver chooses a proper toolchain based on the target platform before leveraging its knowledge to do the following:

  1. Execute the correct assembler, linker, or any tool that is required for the target code's generation.
  2. Pass platform-specific flags to the compiler, assembler, or linker.

This information is crucial for building the source code since each platform might have its own unique characteristics, such as system library paths and supported...