LLVMSwift

LLVMSwift is a set of Swifty API wrappers for the LLVM C API. It makes compiler development feel great from Swift!

Usage

To start emitting IR, you'll want to create a Module object, with an optional Context parameter, and an IRBuilder that will build instructions for that module.

let module = Module(name: "main")
let builder = IRBuilder(module: module)

Once you do that, you can start adding functions, global variables, and generating instructions!

let main = builder.addFunction(name: "main", 
                               type: FunctionType(argTypes: [], 
                                                  returnType: VoidType())
let entry = function.appendBasicBlock(named: "entry")
builder.positionAtEnd(of: entry)

builder.buildRetVoid()

module.dump()

The IRBuilder class has methods for almost all functions from the LLVM C API, like:

• builder.buildAdd
• builder.buildSub
• builder.buildMul
• builder.buildCondBr
• builder.addSwitch

and so many more.

Plus, it provides common wrappers around oft-used types like Function, Global, Switch, and PhiNode.

Installation

There are a couple, annoying steps you need to get it working before it'll build.

• Install LLVM 3.9 using your favorite package manager. For example:
  • brew install llvm
• Ensure llvm-config is in your PATH
  • That will reside in the /bin folder wherever your package manager installed LLVM.
• Create a pkg-config file for your specific LLVM installation.
  • We have a utility for this: swift utils/make-pkgconfig.swift

Once you do that, you can add LLVMSwift as a dependency for your own Swift compiler projects!

This project is used by Trill for all its code generation.

Authors

• Harlan Haskins (@harlanhaskins)
• Robert Widmann (@CodaFi)

License

This project is released under the MIT license, a copy of which is available in this repo.