view contrib/check-py3-compat.py @ 28388:b1d35e2e1af6 stable

mq: restrict generated patch name to 75 characters (issue5117)

Super long first line in description lead to very long file name that
windows is unhappy about. We restrict the name to 75 char to avoid the
issue.

75 seems fine and leave some extra room for '__#' suffix in case of conflict.

I does not seems worthwhile to add a dedicated config option to configure the
length. It can be done in the future if there is an actual user demand for it.

#!/usr/bin/env python
#
# check-py3-compat - check Python 3 compatibility of Mercurial files
#
# Copyright 2015 Gregory Szorc <[e-mail]>
#
# 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)