code: def jarSources(target, source, env, for_signature):
      
      try:
          env['JARCHDIR']
      except KeyError:
          jarchdir_set = False
      else:
          jarchdir_set = True
          jarchdir = env.subst('$JARCHDIR', target=target, source=source)
          if jarchdir:
              jarchdir = env.fs.Dir(jarchdir)
      result = []
      for src in source:
          contents = src.get_text_contents()
          if contents[:16] != "Manifest-Version":
              if jarchdir_set:
                  _chdir = jarchdir
              else:
                  try:
                      _chdir = src.attributes.java_classdir
                  except AttributeError:
                      _chdir = None
              if _chdir:
                  # If we are changing the dir with -C, then sources should
                  # be relative to that directory.
                  src = SCons.Subst.Literal(src.get_path(_chdir))
                  result.append('-C')
                  result.append(_chdir)
              result.append(src)
      return result
docs: Only include sources that are not a manifest file.