Is there a tool for generating C headers from Rust modules?
A more recent way to do this is https://github.com/eqrion/cbindgen/, which seems to be actively maintained at the time of writing. The accepted answer from @hcs links to a GitHub issue that says that this should be tackled by an external tool.
It looks like this is a requested feature for Rust, but I haven't found any implementations.
UPDATE:
As @HameerAbbasi notes below, cbindgen is the preferred tool for doing this now.
It needs to be used so that I can iron out the kinks, but yes.