def _parse_hdr_level_line(line):
    """Parse a normal line of a header stack file

    Example:
        . ./common/rpc/rpc_client.h
    """
    pos = line.find(' ')
    if pos == -1:
        return -1, ''
    level = pos
    hdr = line[pos + 1:]
    if hdr.startswith('./'):
        hdr = hdr[2:]
    return level, hdr