LLVM bindings for .NET Standard written in C# using ClangSharp (www.clangsharp.org)
C# Other
Switch branches/tags
Nothing to show
Clone or download
frederik-h and mjsabby Add overloads for string attribute functions (#71)
Several functions for handling attributes
take string arguments. In the C-API,
a string is represented as a pointer
together with the length of the string.
This representation is currently exposed
in the LLVMSharp methods.

This commit adds overloads for the
corresponding methods which hide
the unnecessary length arguments.
Latest commit 7ed37c2 Jul 2, 2018



Join the chat at https://gitter.im/mjsabby/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.

LLVMSharp 5.0 NuGet Package for .NET Core 2.0+ (Linux, macOS, Windows) and .NET Framework 4+ - built from the LLVM 5.0.0 Release.

Building LLVMSharp

On Linux using .NET Core:

 $ git clone http://github.com/Microsoft/LLVMSharp
 $ cd LLVMSharp/src
 $ 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/mjsabby/LLVMSharp
 :> cd LLVMSharp\src
 :> dotnet build


  • 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)

Kaleidoscope Tutorials

There's a C# translation of the LLVM official Kaleidoscope Tutorial.

Much of the tutorial is already implemented here, and has some nice improvements like the Visitor pattern for code generation to make the LLVM code stand out and help you bootstrap your compiler.

The tutorials have been tested to run on Windows and Linux, however the build (using MSBuild) uses the Nuget packages, hence require some editing to run on Linux.

Chapter 3

Chapter 4

Chapter 5


  • Types are exactly how they are defined in the C bindings, for example: LLVMTypeRef

  • Functions are put in a C# class called LLVM and the LLVM prefix is removed from the functions, for example: LLVM.ModuleCreateWithName("LLVMSharpIntro");

Example application

    using System;
    using System.Runtime.InteropServices;
    using LLVMSharp;

    internal sealed class Program
        public delegate int Add(int a, int b);

        private static void Main(string[] args)
            LLVMBool Success = new LLVMBool(0);
            LLVMModuleRef mod = LLVM.ModuleCreateWithName("LLVMSharpIntro");

            LLVMTypeRef[] param_types = { LLVM.Int32Type(), LLVM.Int32Type() };
            LLVMTypeRef ret_type = LLVM.FunctionType(LLVM.Int32Type(), param_types, false);
            LLVMValueRef sum = LLVM.AddFunction(mod, "sum", ret_type);

            LLVMBasicBlockRef entry = LLVM.AppendBasicBlock(sum, "entry");

            LLVMBuilderRef builder = LLVM.CreateBuilder();
            LLVM.PositionBuilderAtEnd(builder, entry);
            LLVMValueRef tmp = LLVM.BuildAdd(builder, LLVM.GetParam(sum, 0), LLVM.GetParam(sum, 1), "tmp");
            LLVM.BuildRet(builder, tmp);

            if (LLVM.VerifyModule(mod, LLVMVerifierFailureAction.LLVMPrintMessageAction, out var error) != Success)
                Console.WriteLine($"Error: {error}");



            LLVMMCJITCompilerOptions options = new LLVMMCJITCompilerOptions { NoFramePointerElim = 1 };
            if (LLVM.CreateMCJITCompilerForModule(out var engine, mod, options, out error) != Success)
                Console.WriteLine($"Error: {error}");

            var addMethod = (Add)Marshal.GetDelegateForFunctionPointer(LLVM.GetPointerToGlobal(engine, sum), typeof(Add));
            int result = addMethod(10, 10);

            Console.WriteLine("Result of sum is: " + result);

            if (LLVM.WriteBitcodeToFile(mod, "sum.bc") != 0)
                Console.WriteLine("error writing bitcode to file, skipping");



Microsoft Open Source Code of Conduct

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.