fn cc()

in ring/build.rs [524:621]
81 lines of code
20 McCabe index (conditional complexity)

fn cc(
    file: &Path,
    ext: &str,
    target: &Target,
    warnings_are_errors: bool,
    out_dir: &Path,
) -> Command {
    let is_musl = target.env.starts_with("musl");

    let mut c = cc::Build::new();
    let _ = c.include("include");
    match ext {
        "c" => {
            for f in c_flags(target) {
                let _ = c.flag(f);
            }
        }
        "S" => (),
        e => panic!("Unsupported file extension: {:?}", e),
    };
    for f in cpp_flags(target) {
        let _ = c.flag(&f);
    }
    if target.os != "none"
        && target.os != "redox"
        && target.os != "windows"
        && target.arch != "wasm32"
    {
        let _ = c.flag("-fstack-protector");
    }

    match (target.os.as_str(), target.env.as_str()) {
        // ``-gfull`` is required for Darwin's |-dead_strip|.
        ("macos", _) => {
            let _ = c.flag("-gfull");
        }
        (_, "msvc") => (),
        _ => {
            let _ = c.flag("-g3");
        }
    };
    if !target.is_debug {
        let _ = c.define("NDEBUG", None);
    }

    if &target.env == "msvc" {
        if std::env::var("OPT_LEVEL").unwrap() == "0" {
            let _ = c.flag("/Od"); // Disable optimization for debug builds.
                                   // run-time checking: (s)tack frame, (u)ninitialized variables
            let _ = c.flag("/RTCsu");
        } else {
            let _ = c.flag("/Ox"); // Enable full optimization.
        }
    }

    // Allow cross-compiling without a target sysroot for these targets.
    //
    // poly1305_vec.c requires <emmintrin.h> which requires <stdlib.h>.
    if (target.arch == "wasm32" && target.os == "unknown")
        || (target.os == "linux" && is_musl && target.arch != "x86_64")
    {
        if let Ok(compiler) = c.try_get_compiler() {
            // TODO: Expand this to non-clang compilers in 0.17.0 if practical.
            if compiler.is_like_clang() {
                let _ = c.flag("-nostdlibinc");
                let _ = c.define("GFp_NOSTDLIBINC", "1");
            }
        }
    }

    if warnings_are_errors {
        let flag = if &target.env != "msvc" {
            "-Werror"
        } else {
            "/WX"
        };
        let _ = c.flag(flag);
    }
    if is_musl {
        // Some platforms enable _FORTIFY_SOURCE by default, but musl
        // libc doesn't support it yet. See
        // http://wiki.musl-libc.org/wiki/Future_Ideas#Fortify
        // http://www.openwall.com/lists/musl/2015/02/04/3
        // http://www.openwall.com/lists/musl/2015/06/17/1
        let _ = c.flag("-U_FORTIFY_SOURCE");
    }

    let mut c = c.get_compiler().to_command();
    let _ = c
        .arg("-c")
        .arg(format!(
            "{}{}",
            target.obj_opt,
            out_dir.to_str().expect("Invalid path")
        ))
        .arg(file);
    c
}