cargo-expand/build.rs

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

fn main() {
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rustc-check-cfg=cfg(host_os, values(\"windows\"))");

    let prettyplease_version = match env::var("DEP_PRETTYPLEASE02_VERSION") {
        Ok(prettyplease_version) => format!(r#"Some("{}")"#, prettyplease_version.escape_debug()),
        Err(_) => "None".to_owned(),
    };

    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
    let prettyplease_version_file = out_dir.join("prettyplease.version");
    fs::write(prettyplease_version_file, prettyplease_version).unwrap();

    let host = env::var_os("HOST").unwrap();
    if let Some("windows") = host.to_str().unwrap().split('-').nth(2) {
        println!("cargo:rustc-cfg=host_os=\"windows\"");
    }
}