docs: def _generate_regex(self, line):
          '''
          Generates a regular expression from the magic bytes of a signature.
          The regex is used by Magic._analyze.
  
          @line - The first SignatureLine object of the signature.
  
          Returns a compile regular expression.
          '''
          restr = ""
  
          # Strings and single byte signatures are taken at face value;
          # multi-byte integer values are turned into regex strings based
          # on their data type size and endianness.
          if line.type == 'regex':
              # Regex types are already compiled expressions.
              # Note that since re.finditer is used, unless the specified
              # regex accounts for it, overlapping signatures will be ignored.
              return line.value
          if line.type == 'string':
              restr = line.value
          elif line.size == 1:
              restr = chr(line.value)
          elif line.size == 2:
              if line.endianness == '<':
                  restr = chr(line.value & 0xFF) + chr(line.value >> 8)
              elif line.endianness == '>':
                  restr = chr(line.value >> 8) + chr(line.value & 0xFF)
          elif line.size == 4:
              if line.endianness == '<':
                  restr = (chr(line.value & 0xFF) +
                           chr((line.value >> 8) & 0xFF) +
                           chr((line.value >> 16) & 0xFF) +
                           chr(line.value >> 24))
              elif line.endianness == '>':
                  restr = (chr(line.value >> 24) +
                           chr((line.value >> 16) & 0xFF) +
                           chr((line.value >> 8) & 0xFF) +
                           chr(line.value & 0xFF))
          elif line.size == 8:
              if line.endianness == '<':
                  restr = (chr(line.value & 0xFF) +
                           chr((line.value >> 8) & 0xFF) +
                           chr((line.value >> 16) & 0xFF) +
                           chr((line.value >> 24) & 0xFF) +
                           chr((line.value >> 32) & 0xFF) +
                           chr((line.value >> 40) & 0xFF) +
                           chr((line.value >> 48) & 0xFF) +
                           chr(line.value >> 56))
              elif line.endianness == '>':
                  restr = (chr(line.value >> 56) +
                           chr((line.value >> 48) & 0xFF) +
                           chr((line.value >> 40) & 0xFF) +
                           chr((line.value >> 32) & 0xFF) +
                           chr((line.value >> 24) & 0xFF) +
                           chr((line.value >> 16) & 0xFF) +
                           chr((line.value >> 8) & 0xFF) +
                           chr(line.value & 0xFF))
  
          # Since re.finditer is used on a per-signature basis, signatures should be crafted carefully
          # to ensure that they aren't potentially self-overlapping (e.g., a signature of "ABCDAB" could
          # be confused by the byte sequence "ABCDABCDAB"). The longer the signature, the less likely an
          # unintentional overlap is, although files could still be maliciously crafted to cause false
          # negative results.
          #
          # Thus, unless a signature has been explicitly marked as knowingly overlapping ('{overlap}'),
          # spit out a warning about any self-overlapping signatures.
          if not binwalk.core.compat.has_key(line.tags, 'overlap'):
              for i in range(1, line.size):
                  if restr[i:] == restr[0:(line.size - i)]:
                      binwalk.core.common.warning("Signature '%s' is a self-overlapping signature!" % line.text)
                      break
  
          return re.compile(re.escape(restr))