Our Porting Environment

I recommend grabbing this from the repo (ex05_porting) rather than retyping the whole thing. We'll use that as a starting point.

Let's take a quick look around what we have:

• src
  • clib.h - the C library we're going to be working with.
  • clib.c - the C header for the library.
  • lib.rs - a Rust library you are building, to port your amazing C library.
• build.rs - the same Bindgen and CC setup you used before.
• Cargo.toml - has bindgen and cc as dev dependencies.

If you look at clib.h, we're starting with a really simple C function:

char double_byte(char n);

In lib.rs, we've imported the source and setup a simple unit test:

#![allow(unused)]
fn main() {
mod c_lib {
    include!(concat!(env!("OUT_DIR"), "/clib.rs"));
}

#[cfg(test)]
mod tests {
    use super::c_lib::*;

    #[test]
    fn test_double() {
        unsafe {
            assert_eq!(double_byte(2), 4);
        }
    }
}
}

You can even run it, the unit tests pass. Hooray! C and Rut agree, 2 times 2 equals 4.