#!/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 imp

import os

import sys

import traceback

def check_compat_py2(f):

    """Check Python 3 compatibility for a file with Python 2"""

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

        content = fh.read()

    root = ast.parse(content)

    # Ignore empty files.

    if not root.body:

        return

    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)

def check_compat_py3(f):

    """Check Python 3 compatibility of a file with Python 3."""

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

        content = fh.read()

    try:

        ast.parse(content)

    except SyntaxError as e:

        print('%s: invalid syntax: %s' % (f, e))

        return

    # Try to import the module.

    # For now we only support mercurial.* and hgext.* modules because figuring

    # out module paths for things not in a package can be confusing.

    if f.startswith(('hgext/', 'mercurial/')) and not f.endswith('__init__.py'):

        assert f.endswith('.py')

        name = f.replace('/', '.')[:-3]

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

            try:

                imp.load_module(name, fh, '', ('py', 'r', imp.PY_SOURCE))

            except Exception as e:

                exc_type, exc_value, tb = sys.exc_info()

                frame = traceback.extract_tb(tb)[-1]

                if frame.filename:

                    filename = os.path.basename(frame.filename)

                    print('%s: error importing: <%s> %s (error at %s:%d)' % (

                          f, type(e).__name__, e, filename, frame.lineno))

                else:

                    print('%s: error importing module: <%s> %s (line %d)' % (

                          f, type(e).__name__, e, frame.lineno))

if __name__ == '__main__':

    if sys.version_info[0] == 2:

        fn = check_compat_py2

    else:

        fn = check_compat_py3

    for f in sys.argv[1:]:

        fn(f)

    sys.exit(0)