tweedegolf / crc-in-c Goto Github PK

cargo new crc-in-c and cd crc-in-c

Copy crc.c and crc.h

Add the cc build dependency, by adding to Crate.toml the lines:

[build-dependencies]
cc = "1.0"

Create build.rs with contents

extern crate cc;

fn main() {
    cc::Build::new().file("crc32.c").compile("crc32.a");
}

This will find your c code, compile it, and link it into the executable rust produces

Define an extern (fill in the argument and return types)

extern "C" {
    fn CRC32( ... ) -> ...; // hint: https://doc.rust-lang.org/std/os/raw
}

Create a rust wrapper that calls the extern function

fn crc32( ... ) -> ... { 
    ... // (hints: `unsafe`, `.as_ptr()`, `.len()`)
}

Call our wrapper on some example input

fn main() {
    println!("{}", crc32(b"12345678"));
}