Cranelift codegen backend for rust

The goal of this project is to create an alternative codegen backend for the rust compiler based on Cranelift. This has the potential to improve compilation times in debug mode. If your project doesn't use any of the things listed under "Not yet supported", it should work fine. If not please open an issue.

Building and testing

$ git clone https://github.com/bjorn3/rustc_codegen_cranelift
$ cd rustc_codegen_cranelift
$ ./y.rs prepare
$ ./y.rs build

To run the test suite replace the last command with:

$ ./test.sh

For more docs on how to build and test see build_system/usage.txt or the help message of ./y.rs.

Precompiled builds

Alternatively you can download a pre built version from the releases page. Extract the dist directory in the archive anywhere you want. If you want to use cargo clif build instead of having to specify the full path to the cargo-clif executable, you can add the bin subdirectory of the extracted dist directory to your PATH. (tutorial for Windows, and for Linux/MacOS).

Usage

rustc_codegen_cranelift can be used as a near-drop-in replacement for cargo build or cargo run for existing projects.

Assuming $cg_clif_dir is the directory you cloned this repo into and you followed the instructions (y.rs prepare and y.rs build or test.sh).

In the directory with your project (where you can do the usual cargo build), run:

$ $cg_clif_dir/dist/cargo-clif build

This will build your project with rustc_codegen_cranelift instead of the usual LLVM backend.

For additional ways to use rustc_codegen_cranelift like the JIT mode see usage.md.

Configuration

See the documentation on the BackendConfig struct in config.rs for all configuration options.

Not yet supported

• Inline assembly (no cranelift support)
  • On UNIX there is support for invoking an external assembler for global_asm! and asm!.
• SIMD (tracked here, std::simd fully works, std::arch is partially supported)
• Unwinding on panics (no cranelift support, -Cpanic=abort is enabled by default)

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.