Building c2rust

c2rust is a really neat and useful tool :) Unfortunately I had some difficulty building c2rust, here are some notes on how I got it to work.

The c2rust build depends on the host environment, so basically you don't want to build it there or it will break. Building it in a container is the way to go. The c2rust repo has a docker subdirectory, but for some reason it just seems to be for setting up a build environment to build c2rust; it doesn't go all the way and just give you the binary. And the instructions don't actually say what to do with the scripts there, at least as far as I can tell (I may have missed something!), so it's all a bit confusing.

Here's what worked for me on Fedora:

1. Create a Containerfile:

   FROM docker://immunant/c2rust:archlinux-base-latest
   
   RUN git clone https://github.com/immunant/c2rust.git
   WORKDIR c2rust
   RUN cargo +nightly-2019-12-05 build --release --locked
   
   ENTRYPOINT ["/c2rust/target/release/c2rust"]
   

2. Build it (this will take a while):

   podman build -f Containerfile -t c2rust
   

3. Run it in the container:

   podman run -v$PWD:/host:z c2rust transpile --output-dir /host/transpile/ /host/compile_commands.json
   

That last step assumes that you have a compile_commands.json in the current directory and that the paths it references are under /host. The output will go to /host/transpile.