Setting up a development environment

There are three ways to build the C2Rust project:

The previous two options automatically install all prerequisites during provisioning. You can also provision a macOS or Linux system manually.

  • If you are on a Debian-based OS, you can run scripts/ to do so.

  • If you are on macOS, install the Xcode command-line tools (e.g., xcode-select --install) and homebrew first. Then run scripts/

  • If you prefer to install dependencies yourself, or are using a non Debian-based Linux OS, our dependencies are as follows:

    • cmake >= 3.9.1
    • dirmngr
    • curl
    • git
    • gnupg2
    • gperf
    • ninja
    • unzip
    • clang 5.0+
    • intercept-build or bear - see why here
    • python-dev
    • python 3.6+
    • python dependencies
    • rustc version
    • rustfmt-preview component for the above rustc version
    • libssl (development library, dependency of the refactoring tool)

Building with system LLVM libraries

The quickest way to build the C2Rust transpiler is with LLVM and clang system libraries (LLVM 6 and 7 are currently supported). If you have and the libclang libraries (libclangAST.a, libclangTooling.a, etc. or their shared variants) installed, you can build the transpiler with:

$ cd c2rust-transpile
$ cargo build

You can customize the location where the build system will look for LLVM using the following environment variables at compile time:

  • LLVM_CONFIG_PATH = Path to the llvm-config tool of the LLVM installation
  • LLVM_LIB_DIR = Path to the lib directory of the LLVM installation (not necessary if you use LLVM_CONFIG_PATH)
  • LLVM_SYSTEM_LIBS = Additional system libraries LLVM needs to link against (e.g. -lz -lrt -ldl). Not necessary with llvm-config.
  • CLANG_PATH = Path to a clang that is the same version as your If this is necessary the build system will return an error message explaining as much.

C2Rust (indirectly) uses the clang-sys crate which can be configured with its own environment variables.

Building dependencies from source

To develop on components that interact with LLVM, we recommend building against a local copy of LLVM. This will ensure that you have debug symbols and IDE integration for both LLVM and C2Rust. However, building C2Rust from source with LLVM takes a while. For a shorter build that links against prebuilt LLVM and clang system libraries, you should be able to cargo build in the c2rust-transpile directory (see the general README).

The following from source full build script has been tested on recent versions of macOS and Ubuntu:

$ ./scripts/

This downloads and builds LLVM under a new top-level folder named build. Use the C2RUST_BUILD_SUFFIX variable to do multiple side-by-side builds against a local copy of LLVM like this:

$ C2RUST_BUILD_SUFFIX=.debug ./scripts/ --debug

NOTE: Set C2RUST_BUILD_SUFFIX if building inside and outside of the provided Docker or Vagrant environments from a single C2Rust checkout.

Testing (Optional)

Tests are found in the tests folder. If you build the translator successfully, you should be able to run the tests with:

$ ./scripts/ tests

This basically tests that the original C file and translated Rust file produce the same output when compiled and run. More details about tests can be found in the tests folder.