build.rs

extern crate cbindgen;

use std::env;
use std::path::PathBuf;

fn main() {
    let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let target_dir = get_target_dir(&crate_dir);
    let profile = env::var("PROFILE").unwrap();
    let package_name = env::var("CARGO_PKG_NAME").unwrap();
    let output_file_buf = target_dir.join(profile).join(format!("{}.h", package_name));
    let output_file = output_file_buf.to_str().unwrap();

    let config = cbindgen::Config {
        language: cbindgen::Language::C,
        ..Default::default()
    };

    match cbindgen::generate_with_config(&crate_dir, config) {
        Err(e) => println!("{}", e),
        Ok(v) => {
            v.write_to_file(&output_file);
        }
    }
}

fn get_target_dir(crate_dir: &str) -> PathBuf {
    match env::var("CARGO_TARGET_DIR") {
        Ok(d) => PathBuf::from(d),
        Err(_) => PathBuf::from(crate_dir).join("target"),
    }
}