Cretonne is a low-level retargetable code generator. It translates a target-independent intermediate representation into executable machine code.
For more information, see the documentation.
Cretonne currently supports enough functionality to run a wide variety of programs, including all the functionality needed to execute WebAssembly MVP functions, although it needs to be used within an external WebAssembly embedding to be part of a complete WebAssembly implementation.
The x86-64 backend is currently the most complete and stable; other architectures are in various stages of development. Cretonne currently supports the System V AMD64 ABI calling convention used on many platforms, but does not yet support the Windows x64 calling convention. The performance of code produced by Cretonne is not yet impressive, though we have plans to fix that.
The core codegen crates have minimal dependencies, and do not require any host floating-point support. Support for no_std mode in the core codegen crates is in development.
Cretonne does not yet perform mitigations for Spectre or related security issues, though it may do so in the future. It does not currently make any security-relevant instruction timing guarantees. It has seen a fair amount of testing and fuzzing, although more work is needed before it would be ready for a production use case.
Cretonne's APIs are not yet stable.
Cretonne currently supports Rust 1.22.1 and later. We intend to always support the latest stable Rust. And, we currently support the version of Rust in the latest Ubuntu LTS, although whether we will always do so is not yet determined. Cretonne requires Python 2.7 or Python 3 to build.
Cretonne is designed to be a code generator for WebAssembly, but it is general enough to be useful elsewhere too. The initial planned uses that affected its design are:
- WebAssembly compiler for the SpiderMonkey engine in Firefox.
- Backend for the IonMonkey JavaScript JIT compiler in Firefox.
- Debug build backend for the Rust compiler.
Cretonne is using the Cargo package manager format. First, ensure you have installed a current stable rust (stable, beta, and nightly should all work, but only stable and beta are tested consistently). Then, change the working directory to your clone of cretonne and run:
cargo build
This will create a target/debug directory where you can find the generated binary.
To build the optimized binary for release:
cargo build --release
You can then run tests with:
./test-all.sh
You may need to install the wat2wasm tool from the wabt project in order to run all of the WebAssembly tests. Tests requiring wat2wasm are ignored if the tool is not installed.
To build the Cretonne documentation, you need the Sphinx documentation generator:
$ pip install sphinx sphinx-autobuild sphinx_rtd_theme $ cd cretonne/docs $ make html $ open _build/html/index.html
We don't support Sphinx versions before 1.4 since the format of index tuples has changed.