AppPkg/Applications/Python/Python-2.7.2/Lib/lib2to3/main.py

   1 """
   2 Main program for 2to3.
   3 """
   4
   5 from __future__ import with_statement
   6
   7 import sys
   8 import os
   9 import difflib
  10 import logging
  11 import shutil
  12 import optparse
  13
  14 from . import refactor
  15
  16
  17 def diff_texts(a, b, filename):
  18     """Return a unified diff of two strings."""
  19     a = a.splitlines()
  20     b = b.splitlines()
  21     return difflib.unified_diff(a, b, filename, filename,
  22                                 "(original)", "(refactored)",
  23                                 lineterm="")
  24
  25
  26 class StdoutRefactoringTool(refactor.MultiprocessRefactoringTool):
  27     """
  28     Prints output to stdout.
  29     """
  30
  31     def __init__(self, fixers, options, explicit, nobackups, show_diffs):
  32         self.nobackups = nobackups
  33         self.show_diffs = show_diffs
  34         super(StdoutRefactoringTool, self).__init__(fixers, options, explicit)
  35
  36     def log_error(self, msg, *args, **kwargs):
  37         self.errors.append((msg, args, kwargs))
  38         self.logger.error(msg, *args, **kwargs)
  39
  40     def write_file(self, new_text, filename, old_text, encoding):
  41         if not self.nobackups:
  42             # Make backup
  43             backup = filename + ".bak"
  44             if os.path.lexists(backup):
  45                 try:
  46                     os.remove(backup)
  47                 except os.error, err:
  48                     self.log_message("Can't remove backup %s", backup)
  49             try:
  50                 os.rename(filename, backup)
  51             except os.error, err:
  52                 self.log_message("Can't rename %s to %s", filename, backup)
  53         # Actually write the new file
  54         write = super(StdoutRefactoringTool, self).write_file
  55         write(new_text, filename, old_text, encoding)
  56         if not self.nobackups:
  57             shutil.copymode(backup, filename)
  58
  59     def print_output(self, old, new, filename, equal):
  60         if equal:
  61             self.log_message("No changes to %s", filename)
  62         else:
  63             self.log_message("Refactored %s", filename)
  64             if self.show_diffs:
  65                 diff_lines = diff_texts(old, new, filename)
  66                 try:
  67                     if self.output_lock is not None:
  68                         with self.output_lock:
  69                             for line in diff_lines:
  70                                 print line
  71                             sys.stdout.flush()
  72                     else:
  73                         for line in diff_lines:
  74                             print line
  75                 except UnicodeEncodeError:
  76                     warn("couldn't encode %s's diff for your terminal" %
  77                          (filename,))
  78                     return
  79
  80
  81 def warn(msg):
  82     print >> sys.stderr, "WARNING: %s" % (msg,)
  83
  84
  85 def main(fixer_pkg, args=None):
  86     """Main program.
  87
  88     Args:
  89         fixer_pkg: the name of a package where the fixers are located.
  90         args: optional; a list of command line arguments. If omitted,
  91               sys.argv[1:] is used.
  92
  93     Returns a suggested exit status (0, 1, 2).
  94     """
  95     # Set up option parser
  96     parser = optparse.OptionParser(usage="2to3 [options] file|dir ...")
  97     parser.add_option("-d", "--doctests_only", action="store_true",
  98                       help="Fix up doctests only")
  99     parser.add_option("-f", "--fix", action="append", default=[],
 100                       help="Each FIX specifies a transformation; default: all")
 101     parser.add_option("-j", "--processes", action="store", default=1,
 102                       type="int", help="Run 2to3 concurrently")
 103     parser.add_option("-x", "--nofix", action="append", default=[],
 104                       help="Prevent a transformation from being run")
 105     parser.add_option("-l", "--list-fixes", action="store_true",
 106                       help="List available transformations")
 107     parser.add_option("-p", "--print-function", action="store_true",
 108                       help="Modify the grammar so that print() is a function")
 109     parser.add_option("-v", "--verbose", action="store_true",
 110                       help="More verbose logging")
 111     parser.add_option("--no-diffs", action="store_true",
 112                       help="Don't show diffs of the refactoring")
 113     parser.add_option("-w", "--write", action="store_true",
 114                       help="Write back modified files")
 115     parser.add_option("-n", "--nobackups", action="store_true", default=False,
 116                       help="Don't write backups for modified files")
 117
 118     # Parse command line arguments
 119     refactor_stdin = False
 120     flags = {}
 121     options, args = parser.parse_args(args)
 122     if not options.write and options.no_diffs:
 123         warn("not writing files and not printing diffs; that's not very useful")
 124     if not options.write and options.nobackups:
 125         parser.error("Can't use -n without -w")
 126     if options.list_fixes:
 127         print "Available transformations for the -f/--fix option:"
 128         for fixname in refactor.get_all_fix_names(fixer_pkg):
 129             print fixname
 130         if not args:
 131             return 0
 132     if not args:
 133         print >> sys.stderr, "At least one file or directory argument required."
 134         print >> sys.stderr, "Use --help to show usage."
 135         return 2
 136     if "-" in args:
 137         refactor_stdin = True
 138         if options.write:
 139             print >> sys.stderr, "Can't write to stdin."
 140             return 2
 141     if options.print_function:
 142         flags["print_function"] = True
 143
 144     # Set up logging handler
 145     level = logging.DEBUG if options.verbose else logging.INFO
 146     logging.basicConfig(format='%(name)s: %(message)s', level=level)
 147
 148     # Initialize the refactoring tool
 149     avail_fixes = set(refactor.get_fixers_from_package(fixer_pkg))
 150     unwanted_fixes = set(fixer_pkg + ".fix_" + fix for fix in options.nofix)
 151     explicit = set()
 152     if options.fix:
 153         all_present = False
 154         for fix in options.fix:
 155             if fix == "all":
 156                 all_present = True
 157             else:
 158                 explicit.add(fixer_pkg + ".fix_" + fix)
 159         requested = avail_fixes.union(explicit) if all_present else explicit
 160     else:
 161         requested = avail_fixes.union(explicit)
 162     fixer_names = requested.difference(unwanted_fixes)
 163     rt = StdoutRefactoringTool(sorted(fixer_names), flags, sorted(explicit),
 164                                options.nobackups, not options.no_diffs)
 165
 166     # Refactor all files and directories passed as arguments
 167     if not rt.errors:
 168         if refactor_stdin:
 169             rt.refactor_stdin()
 170         else:
 171             try:
 172                 rt.refactor(args, options.write, options.doctests_only,
 173                             options.processes)
 174             except refactor.MultiprocessingUnsupported:
 175                 assert options.processes > 1
 176                 print >> sys.stderr, "Sorry, -j isn't " \
 177                     "supported on this platform."
 178                 return 1
 179         rt.summarize()
 180
 181     # Return error status (0 if rt.errors is zero)
 182     return int(bool(rt.errors))