LLVMSharp

LLVMSharp is a multi-platform .NET Standard library for accessing the LLVM infrastructure. The bindings are auto-generated using ClangSharp parsing LLVM-C header files.

A nuget package for the project is provided here: https://www.nuget.org/packages/llvmsharp.

A convenience package which provides the native libLLVM library for several platforms is provided here: https://www.nuget.org/packages/libLLVM

Source browsing is available via: https://source.clangsharp.dev/

Table of Contents

• Code of Conduct
• License
• Features
• Building LLVMSharp
• Regenerating native binaries

Code of Conduct

LLVMSharp and everyone contributing (this includes issues, pull requests, the wiki, etc) must abide by the .NET Foundation Code of Conduct: https://dotnetfoundation.org/about/code-of-conduct.

Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at conduct@dotnetfoundation.org.

License

Copyright (c) .NET Foundation and Contributors. All Rights Reserved. Licensed under the MIT License (MIT). See LICENSE.md in the repository root for more information.

Features

• Auto-generated using LLVM C headers files, and supports all functionality exposed by them (more than enough to build a full compiler)
• Type safe (LLVMValueRef and LLVMTypeRef are different types, despite being pointers internally)
• Nearly identical to LLVM C APIs, e.g. LLVMModuleCreateWithName in C, vs. LLVM.ModuleCreateWithName (notice the . in the C# API)

Building LLVMSharp

On Linux using .NET Core:

 $ git clone http://github.com/dotnet/llvmsharp
 $ cd LLVMSharp
 $ dotnet build

On Windows using .NET Core

Note: - you need to run these commands from the Visual Studio Developer Command Prompt.

 :> git clone http://github.com/dotnet/LLVMSharp
 :> cd LLVMSharp
 :> dotnet build

Regenerating native binaries

The native runtime packages are produced by CI (.github/workflows/regenerate-native.yml) rather than by hand:

• libLLVM.runtime.* (and the libLLVM meta-package) — the prebuilt shared libLLVM library.
• libLLVMSharp.runtime.* (and the libLLVMSharp meta-package) — the libLLVMSharp helper, compiled from sources/libLLVMSharp against the matching LLVM release.

The tracked LLVM version is the project(LLVMSharp VERSION X.Y.Z) value in the top-level CMakeLists.txt, which maps to the llvmorg-X.Y.Z release tag. For each runtime (win-x64, win-arm64, linux-x64, linux-arm64, osx-arm64) the download-and-stage step is handled by scripts/build.ps1/scripts/build.sh:

# lift the prebuilt libLLVM (win-* on Windows)
./scripts/build.ps1 -regeneratenative -target libLLVM -rid win-x64

# lift the prebuilt libLLVM (linux-*/osx-* on the matching runner)
./scripts/build.sh --regeneratenative --target libLLVM --rid linux-x64

# compile libLLVMSharp against the matching LLVM release
./scripts/build.sh --regeneratenative --target libLLVMSharp --rid linux-x64

The staged binary is written to artifacts/native/<rid>/. Unlike ClangSharp — which lifts the shared libclang that ships for every platform — the official LLVM releases only ship a shared libLLVM on Windows (as LLVM-C.dll, shipped under that official name). The managed resolver in sources/LLVMSharp.Interop/LLVM.cs maps the logical libLLVM P/Invoke name to the per-platform file (LLVM-C.dll on Windows; libLLVM.so/libLLVM.dylib elsewhere), which is also why libLLVMSharp.dll's static LLVM-C.dll import resolves without an extra copy. Linux and macOS are lifted from the most-official prebuilt source per platform: apt.llvm.org (the LLVM project's own Debian/Ubuntu repository, libllvm<major>) on Linux and Homebrew (llvm) on macOS, both of which link the standard system C++ runtime. Windows and Linux compile libLLVMSharp against the official release SDK; macOS uses the exact Homebrew formula on a macOS 15 runner and requires users to install that formula for its external dependencies.

The jobs run when:

• libLLVM — the tracked LLVM major/minor version changes, or the workflow is dispatched manually with the libllvm input set.
• libLLVMSharp — the same LLVM version change, or anything under sources/libLLVMSharp/ changes, or the workflow is dispatched manually with the libllvmsharp input set.

Before anything is downloaded, the workflow verifies the packages/**/*.nuspec and packages/**/runtime.json versions match the tracked LLVM version (libLLVM exactly; libLLVMSharp as <llvm-version>.<revision>), so a version bump that forgot to update a package fails fast. Each job uploads the resulting .nupkg files as build artifacts and signs them; publishing them to NuGet.org is a manual step. To move to a new LLVM release, bump the version in CMakeLists.txt alongside the <version> in the affected packages/**/*.nuspec files (and the versions in packages/**/runtime.json and this README); pushing that change regenerates the packages.