import subprocess


def getRoot(config):
    if not config.parent:
        return config
    return getRoot(config.parent)


def is_gold_linker_available():

    if not config.gold_executable:
        return False
    try:
        ld_cmd = subprocess.Popen(
            [config.gold_executable, "--help"], stdout=subprocess.PIPE
        )
        ld_out = ld_cmd.stdout.read().decode()
        ld_cmd.wait()
    except:
        return False

    if not "-plugin" in ld_out:
        return False

    # config.clang is not guaranteed to be just the executable!
    clang_cmd = subprocess.Popen(
        " ".join([config.clang, "-fuse-ld=gold", "-xc", "-"]),
        shell=True,
        universal_newlines=True,
        stdin=subprocess.PIPE,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
    )
    clang_err = clang_cmd.communicate("int main() { return 0; }")[1]

    if not "invalid linker" in clang_err:
        return True

    return False


root = getRoot(config)

if root.host_os not in ["Linux"] or not is_gold_linker_available():
    config.unsupported = True

if config.have_curl:
    config.available_features.add("curl")