Install LLVM 19 and necessary tools for compiler development on ubuntu 24.04

This guide walks you through installing the essential development tools and libraries for C/C++ and compiler development on Ubuntu 24.04:

  • LLVM 19 + Clang
  • CMake
  • libffi
  • libxml2
  • zlib

⚙️ Prerequisites

Make sure your system is up to date:

sudo apt update
sudo apt upgrade -y

You’ll also need basic developer tools:

sudo apt install -y build-essential wget curl gnupg software-properties-common

🧠 Step 1: Install LLVM 19 and Clang

Ubuntu 24.04 doesn’t include LLVM 19 in its default repositories, so you’ll need to add the official LLVM APT repository.

Add the LLVM APT Repository

# Add the official LLVM GPG key
wget https://apt.llvm.org/llvm.sh
chmod +x llvm.sh
sudo ./llvm.sh 19

This will install:

  • clang-19
  • llvm-19
  • lld-19
  • libclang-19-dev

Make Clang 19 the Default (optional)

sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-19 100
sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-19 100

🧰 Step 2: Install CMake

Ubuntu 24.04 ships with a relatively recent version of CMake. You can install it directly via:

sudo apt install -y cmake

Need a newer version? You can get the latest from Kitware’s CMake Snap or source.

🧬 Step 3: Install libffi

sudo apt install -y libffi-dev

This installs both the runtime and development headers for libffi.

📄 Step 4: Install libxml2

sudo apt install -y libxml2 libxml2-dev

This includes the runtime library and development headers.

🗜️ Step 5: Install zlib

sudo apt install -y zlib1g zlib1g-dev

zlib1g is the core compression library, and zlib1g-dev provides headers needed to compile against it.

✅ Verification

After installing, you can verify versions:

clang-19 --version
cmake --version
pkg-config --modversion libffi
pkg-config --modversion libxml-2.0

🧪 Troubleshooting

If you run into errors like missing packages or 404s during apt install, try updating your package list again:

sudo apt update

If you’re building LLVM-related projects, ensure you are using the correct Clang and LLVM versions by setting environment variables like:

export CC=clang-19
export CXX=clang++-19

🙌 You’re Ready

You now have a modern LLVM toolchain with essential libraries installed and ready for development on Ubuntu 24.04.

Have questions or need help with building tools? Feel free to ask!