load_extractor.py 文件源码

def _extract_loads(self, bzl_file):
    """Walks the AST and extracts information on loaded symbols."""
    load_symbols = []
    try:
      tree = ast.parse(open(bzl_file).read(), bzl_file)
      key = None
      for node in ast.iter_child_nodes(tree):
        if not isinstance(node, ast.Expr):
          continue
        call = node.value
        if (not isinstance(call, ast.Call) or
            not isinstance(call.func, ast.Name) or
            call.func.id != 'load'):
          continue

        args = []
        for arg in call.args:
          if not isinstance(arg, ast.Str):
            raise LoadExtractorError(
                'Only string literals in load statments are supported.')
          args.append(arg.s)
        kwargs = {}
        for keyword in call.keywords:
          if not isinstance(keyword.value, ast.Str):
            raise LoadExtractorError(
                'Only string literals in load statments are supported.')
          kwargs[keyword.arg] = keyword.value.s

        label = args[0]
        for arg in args[1:]:
          load_symbol = LoadSymbol(label, arg, None)
          load_symbols.append(load_symbol)
        for alias, symbol in kwargs.iteritems():
          load_symbol = LoadSymbol(label, symbol, alias)
          load_symbols.append(load_symbol)

    except IOError:
      print("Failed to parse {0}: {1}".format(bzl_file, e.strerror))
      pass

    return load_symbols