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 env_feature_prefix: &str = "CARGO_FEATURE_";
    let feature_prefix: &str = "feat_";
    let override_prefix: &str = "uu_";

    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(env_feature_prefix) {
            let krate = key[env_feature_prefix.len()..].to_lowercase();
            match krate.as_ref() {
                "default" | "macos" | "unix" | "windows" => continue, // common/standard feature names
                "nightly" | "test_unimplemented" => continue,         // crate-local custom features
                "test" => continue, // over-ridden with 'uu_test' to avoid collision with rust core crate 'test'
                s if s.starts_with(feature_prefix) => continue, // crate feature sets
                _ => {}             // util feature name
            }
            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>;\n\
        \n\
        fn util_map() -> UtilityMap {\n\
        \tlet mut map: UtilityMap = HashMap::new();\n\
        "
        .as_bytes(),
    )
    .unwrap();

    for krate in crates {
        match krate.as_ref() {
            k if k.starts_with(override_prefix) => mf
                .write_all(
                    format!(
                        "\tmap.insert(\"{k}\", {krate}::uumain);\n",
                        k = krate[override_prefix.len()..].to_string(),
                        krate = krate
                    )
                    .as_bytes(),
                )
                .unwrap(),
            "false" | "true" => mf
                .write_all(
                    format!(
                        "\tmap.insert(\"{krate}\", r#{krate}::uumain);\n",
                        krate = krate
                    )
                    .as_bytes(),
                )
                .unwrap(),
            "hashsum" => mf
                .write_all(
                    format!(
                        "\
                        \tmap.insert(\"{krate}\", {krate}::uumain);\n\
                        \t\tmap.insert(\"md5sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha1sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha224sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha256sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha384sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha512sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha3sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha3-224sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha3-256sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha3-384sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"sha3-512sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"shake128sum\", {krate}::uumain);\n\
                        \t\tmap.insert(\"shake256sum\", {krate}::uumain);\n\
                        ",
                        krate = krate
                    )
                    .as_bytes(),
                )
                .unwrap(),
            _ => mf
                .write_all(
                    format!(
                        "\tmap.insert(\"{krate}\", {krate}::uumain);\n",
                        krate = krate
                    )
                    .as_bytes(),
                )
                .unwrap(),
        }
    }

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

    mf.flush().unwrap();
}