Compiles .NET/C# to native code using LLVM framework. No longer active, consider migrating to
C# C++ C CMake Assembly Objective-C
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.


This project is no longer active, consider migrating to

SharpLang is a .NET (MSIL) compiler front-end for LLVM.

It allows you to compile C# and other .NET languages code to any supported LLVM backend.

Official twitter account:


BSD 2-clause license.


Getting Started


  • Fill the gap between managed flexibility/safety/productivity (on by default) and native speed/control (when you actually need it)
  • Supports many platforms (including Windows, MacOSX, mobile devices, consoles, browser)
  • Performance oriented
  • Lightweight runtime
  • Some .NET features that implies too much overhead for to their actual uses will be emulated or dropped (i.e. array covariance -- unsafe and huge performance implication)
  • Various technical choices to avoid unecessary conversions and interop with other languages
  • Provide a good starting point to implement "M#" features as soon as possible (
  • Flexible and controllable (.NET shouldn't be a black box anymore; optimize what you want, pay for what you actually use, etc...)

Planned features

It's still a early work in progress. Any help/feedback is welcome!

What's working

  • Codegen (unit tested)
  • Supports most .NET opcodes
  • Branching
  • Classes and interfaces
  • Generics (expanded like C++ template)
  • PInvoke (simple, no marshalling)
  • Delegate (no multicast delegate yet)
  • Boxing
  • Exceptions (DWARF and SEH)
  • Converts huge libraries (i.e. Mono mscorlib, System, System.Core, System.Xml, etc...)
  • Reflection (only types, no method/field yet)
  • x86 and x64
  • Simple code linked against SharpLang-compiled Mono mscorlib is starting to work (i.e. WinForms+SharpDX)

What's next

  • Driver/Linker
  • Runtime (probably lot will be imported from CoreCLR)
  • Reflection (method, fields, custom attributes)
  • Threads, Locks, etc...
  • I/O
  • Marshalling
  • Vararg
  • GC integration (either CoreCLR, Mono or BoehmGC)
  • Cross-platform
  • Emscripten HTML5 (javascript) support
  • Linux/MacOSX support
  • Android, iOS
  • Code quality
  • Documentation


  • Dynamic loading
  • Performance extensions
  • Non-nullable types
  • SIMD support
  • More control over class/struct layouting (allocate class on stack, etc...)
  • Various "M#" improvements
  • Uniqueness and Reference Immutability for Safe Parallelism:
  • Lifetime control (unique/owned pointers, stack alloc as much as possible with pure functions, etc...)
  • RAII (struct destructors)
  • Use and extend Roslyn for new language extensions
  • Direct (or at least easy) access to C++ (probably with help of libclang)
  • Other platforms

Various technical details

Here for now, until later moved to a more specific documentation.

  • UTF8 string (UTF16 was choosed mainly because of Windows API, but UTF8 is more space efficient, API compatible with char* and avoid many conversions)
  • String/Array indirection to more easily carve substring/subarrays.