cpython/Lib/lib2to3/main.py

"""
Main program for 2to3.
"""

import sys
import os
import logging
import optparse

from . import refactor


class StdoutRefactoringTool(refactor.RefactoringTool):
    """
    Prints output to stdout.
    """

    def log_error(self, msg, *args, **kwargs):
        self.errors.append((msg, args, kwargs))
        self.logger.error(msg, *args, **kwargs)

    def print_output(self, lines):
        for line in lines:
            print(line)


def main(fixer_pkg, args=None):
    """Main program.

    Args:
        fixer_pkg: the name of a package where the fixers are located.
        args: optional; a list of command line arguments. If omitted,
              sys.argv[1:] is used.

    Returns a suggested exit status (0, 1, 2).
    """
    # Set up option parser
    parser = optparse.OptionParser(usage="refactor.py [options] file|dir ...")
    parser.add_option("-d", "--doctests_only", action="store_true",
                      help="Fix up doctests only")
    parser.add_option("-f", "--fix", action="append", default=[],
                      help="Each FIX specifies a transformation; default all")
    parser.add_option("-l", "--list-fixes", action="store_true",
                      help="List available transformations (fixes/fix_*.py)")
    parser.add_option("-p", "--print-function", action="store_true",
                      help="Modify the grammar so that print() is a function")
    parser.add_option("-v", "--verbose", action="store_true",
                      help="More verbose logging")
    parser.add_option("-w", "--write", action="store_true",
                      help="Write back modified files")

    # Parse command line arguments
    refactor_stdin = False
    options, args = parser.parse_args(args)
    if options.list_fixes:
        print("Available transformations for the -f/--fix option:")
        for fixname in refactor.get_all_fix_names(fixer_pkg):
            print(fixname)
        if not args:
            return 0
    if not args:
        print("At least one file or directory argument required.", file=sys.stderr)
        print("Use --help to show usage.", file=sys.stderr)
        return 2
    if "-" in args:
        refactor_stdin = True
        if options.write:
            print("Can't write to stdin.", file=sys.stderr)
            return 2

    # Set up logging handler
    level = logging.DEBUG if options.verbose else logging.INFO
    logging.basicConfig(format='%(name)s: %(message)s', level=level)

    # Initialize the refactoring tool
    rt_opts = {"print_function" : options.print_function}
    avail_names = refactor.get_fixers_from_package(fixer_pkg)
    explicit = []
    if options.fix:
        explicit = [fixer_pkg + ".fix_" + fix
                    for fix in options.fix if fix != "all"]
        fixer_names = avail_names if "all" in options.fix else explicit
    else:
        fixer_names = avail_names
    rt = StdoutRefactoringTool(fixer_names, rt_opts, explicit=explicit)

    # Refactor all files and directories passed as arguments
    if not rt.errors:
        if refactor_stdin:
            rt.refactor_stdin()
        else:
            rt.refactor(args, options.write, options.doctests_only)
        rt.summarize()

    # Return error status (0 if rt.errors is zero)
    return int(bool(rt.errors))