#!/usr/bin/env python

#

# check-py3-compat - check Python 3 compatibility of Mercurial files

#

# Copyright 2015 Gregory Szorc <gregory.szorc@gmail.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

from __future__ import absolute_import, print_function

import ast

import sys

def check_compat(f):

    """Check Python 3 compatibility for a file."""

    with open(f, 'rb') as fh:

        content = fh.read()

    # Ignore empty files.

    if not content.strip():

        return

    root = ast.parse(content)

    futures = set()

    haveprint = False

    for node in ast.walk(root):

        if isinstance(node, ast.ImportFrom):

            if node.module == '__future__':

                futures |= set(n.name for n in node.names)

        elif isinstance(node, ast.Print):

            haveprint = True

    if 'absolute_import' not in futures:

        print('%s not using absolute_import' % f)

    if haveprint and 'print_function' not in futures:

        print('%s requires print_function' % f)

if __name__ == '__main__':

    for f in sys.argv[1:]:

        check_compat(f)

    sys.exit(0)