coreutils/build.rs

// spell-checker:ignore (utils) chgrp chmod chown chroot cksum dircolors hashsum hostid logname mkdir mkfifo mknod mktemp nohup nproc numfmt pathchk printenv printf readlink realpath relpath rmdir shuf stdbuf tsort uname unexpand whoami
// spell-checker:ignore () uutils uumain rustfmt rustc macos krate

use std::env;
use std::fs::File;
use std::io::Write;
use std::path::Path;

pub fn main() {
    if let Ok(profile) = env::var("PROFILE") {
        println!("cargo:rustc-cfg=build={:?}", profile);
    }

    let feature_prefix = "CARGO_FEATURE_";
    let out_dir = env::var("OUT_DIR").unwrap();

    let mut crates = Vec::new();
    for (key, val) in env::vars() {
        if val == "1" && key.starts_with(feature_prefix) {
            let krate = key[feature_prefix.len()..].to_lowercase();
            match krate.as_ref() {
                "default" | "macos" | "unix" | "windows" => continue,
                "nightly" | "test_unimplemented" => continue,
                s if s.starts_with("feat_") => continue,
                _ => {}
            }
            crates.push(krate.to_string());
        }
    }
    crates.sort();

    let mut mf = File::create(Path::new(&out_dir).join("uutils_map.rs")).unwrap();

    mf.write_all(
        "
    type UtilityMap = HashMap<&'static str, fn(Vec<String>) -> i32>;

    fn util_map() -> UtilityMap {
    let mut map: UtilityMap = HashMap::new();\n"
            .as_bytes(),
    )
    .unwrap();

    for krate in crates {
        match krate.as_ref() {
            // ToDO: add another bypass method for publishing name collisions requiring a non-`uu_` prefix for a util
            // * use "uu_" prefix as bypass method to avoid name collisions with imported crates, when necessary (eg, 'test')
            k if k.starts_with("uu_")
                => mf
                    .write_all(
                        format!("map.insert(\"{k}\", {krate}::uumain);\n", k = krate.clone().remove("uu_".len()), krate = krate)
                            .as_bytes(),
                    )
                    .unwrap(),
            "false" | "true" => mf
                .write_all(
                    format!("map.insert(\"{krate}\", r#{krate}::uumain);\n", krate = krate)
                        .as_bytes(),
                )
                .unwrap(),
            "hashsum" => mf
                .write_all(
                    format!(
                        "
                        map.insert(\"{krate}\", {krate}::uumain);
                            map.insert(\"md5sum\", {krate}::uumain);
                            map.insert(\"sha1sum\", {krate}::uumain);
                            map.insert(\"sha224sum\", {krate}::uumain);
                            map.insert(\"sha256sum\", {krate}::uumain);
                            map.insert(\"sha384sum\", {krate}::uumain);
                            map.insert(\"sha512sum\", {krate}::uumain);
                            map.insert(\"sha3sum\", {krate}::uumain);
                            map.insert(\"sha3-224sum\", {krate}::uumain);
                            map.insert(\"sha3-256sum\", {krate}::uumain);
                            map.insert(\"sha3-384sum\", {krate}::uumain);
                            map.insert(\"sha3-512sum\", {krate}::uumain);
                            map.insert(\"shake128sum\", {krate}::uumain);
                            map.insert(\"shake256sum\", {krate}::uumain);\n",
                        krate = krate
                    )
                    .as_bytes(),
                )
                .unwrap(),
            _ => mf
                .write_all(
                    format!(
                        "map.insert(\"{krate}\", {krate}::uumain);\n",
                        krate = krate
                    )
                    .as_bytes(),
                )
                .unwrap(),
        }
    }

    mf.write_all(b"map\n}\n").unwrap();

    mf.flush().unwrap();
}