def METHOD_NAME():
    try:
        output = subprocess.check_output(
            ["git", "rev-parse", "--show-toplevel"], stderr=subprocess.STDOUT
        )
    except subprocess.CalledProcessError as e:
        print(e.output)
        sys.exit(1)
    gitroot = Path(output.decode("utf-8").rstrip())
    try:
        rel_src = src_path.relative_to(gitroot)
    except ValueError:
        print(f"{src_path} not in git repository.")
        sys.exit(1)
    cmd = ["git"]
    cmd.append("diff")
    cmd.append("--name-only")
    cmd.append("--diff-filter=d")
    cmd.append(git_branch)
    # Relative only if source root path specified
    if args.root:
        cmd.append(f"--relative={rel_src}")
    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
    while True:
        line = proc.stdout.readline().decode("utf-8").rstrip()
        if line == "" and proc.poll() is not None:
            break
        if line:
            if line.endswith((".h", ".c", ".hpp", ".cpp")):
                source_list.append(gitroot / line.rstrip())
    if proc.poll() != 0:
        sys.exit(1)
    source_list.sort()