Ever wanted to build “native” assemblyish stuff in your cargo build scripts… something gcc crate cannot quite handle yet? Welcome to llvm_build_utils which provides a convenient API to pack your LLVM-IR or LLVM bytecode files into a ready to use archive full of machine code! It doesn’t even need LLVM installation and works on stable Rust¹!

Documentation

¹: May break between versions or be incompatible with some versions of Rust, though. We’ll try to document such breakages in the table below.

Compatibility table

Rustc version	This Library
1.8-1.11	0.1-0.2

Using llvm_build_utils

First, you’ll want to both add a build script for your crate (build.rs) and also add this crate to your Cargo.toml via:

[package]
# ...
build = "build.rs"

[build-dependencies]
llvm_build_utils = "0.2"

Then write your build.rs like this:

extern crate llvm_build_utils;
use llvm_build_utils::*;

fn main() {
    build_archive("libyourthing.a", &[
        ("input.ll", BuildOptions {
            ..BuildOptions::default() // customise how the file is built
        })
    ]).expect("error happened");
    // ...
}

Running a cargo build should produce libyourthing.a which then may be linked to your Rust executable/library.

License

llvm_build_utils is distributed under ISC (MIT-like) or Apache (version 2.0) license at your choice.