fn main()

in aws-lc-sys/builder/main.rs [680:773]
83 lines of code
9 McCabe index (conditional complexity)

fn main() {
    initialize();
    prepare_cargo_cfg();

    let manifest_dir = current_dir();
    let manifest_dir = dunce::canonicalize(Path::new(&manifest_dir)).unwrap();
    let prefix_str = prefix_string();
    let prefix = if is_no_prefix() {
        None
    } else {
        Some(prefix_str)
    };

    let builder = get_builder(&prefix, &manifest_dir, &out_dir());
    emit_warning(&format!("Building with: {}", builder.name()));
    emit_warning(&format!("Symbol Prefix: {:?}", &prefix));

    builder.check_dependencies().unwrap();

    #[allow(unused_assignments)]
    let mut bindings_available = false;
    if is_pregenerating_bindings() {
        #[cfg(feature = "bindgen")]
        {
            let src_bindings_path = Path::new(&manifest_dir)
                .join("src")
                .join(format!("{}.rs", target_platform_prefix("crypto")));
            if is_external_bindgen() {
                invoke_external_bindgen(&manifest_dir, &prefix, &src_bindings_path).unwrap();
            } else {
                generate_src_bindings(&manifest_dir, &prefix, &src_bindings_path);
            }
            bindings_available = true;
        }
    } else if is_bindgen_required() {
        emit_warning("######");
        emit_warning(
            "If bindgen is unable to locate a header file, use the \
            BINDGEN_EXTRA_CLANG_ARGS environment variable to specify additional include paths.",
        );
        emit_warning("See: https://github.com/rust-lang/rust-bindgen?tab=readme-ov-file#environment-variables");
        emit_warning("######");
        let aws_lc_crypto_dir = Path::new(&manifest_dir).join("aws-lc").join("crypto");
        if !aws_lc_crypto_dir.exists() {
            emit_warning("######");
            emit_warning("###### WARNING: MISSING GIT SUBMODULE ######");
            emit_warning(&format!(
                "  -- Did you initialize the repo's git submodules? Unable to find crypto directory: {}.",
                &aws_lc_crypto_dir.display()
            ));
            emit_warning("  -- run 'git submodule update --init --recursive' to initialize.");
            emit_warning("######");
            emit_warning("######");
        }
        bindings_available = handle_bindgen(&manifest_dir, &prefix);
    } else {
        bindings_available = true;
    }

    if !bindings_available && !cfg!(feature = "ssl") {
        let gen_bindings_path = out_dir().join("bindings.rs");
        let result = invoke_external_bindgen(&manifest_dir, &prefix, &gen_bindings_path);
        match result {
            Ok(()) => {
                emit_rustc_cfg("use_bindgen_generated");
                bindings_available = true;
            }
            Err(msg) => eprintln!("Failure invoking external bindgen! {msg}"),
        }
    }

    assert!(
        bindings_available,
        "aws-lc-sys build failed. Please enable the 'bindgen' feature on aws-lc-rs or aws-lc-sys.\
        For more information, see the aws-lc-rs User Guide: https://aws.github.io/aws-lc-rs/index.html"
    );
    builder.build().unwrap();

    println!(
        "cargo:include={}",
        setup_include_paths(&out_dir(), &manifest_dir).display()
    );

    // export the artifact names
    println!("cargo:libcrypto={}_crypto", prefix_string());
    if cfg!(feature = "ssl") {
        println!("cargo:libssl={}_ssl", prefix_string());
    }

    println!("cargo:conf={}", OSSL_CONF_DEFINES.join(","));

    println!("cargo:rerun-if-changed=builder/");
    println!("cargo:rerun-if-changed=aws-lc/");
}