Add missing issue number in Misc/NEWS entry.
[python.git] / Lib / lib2to3 / main.py
blob736d5a6bd1c4673c7a9476b967dc93b1b5526a5b
1 """
2 Main program for 2to3.
3 """
5 import sys
6 import os
7 import difflib
8 import logging
9 import shutil
10 import optparse
12 from . import refactor
15 def diff_texts(a, b, filename):
16 """Return a unified diff of two strings."""
17 a = a.splitlines()
18 b = b.splitlines()
19 return difflib.unified_diff(a, b, filename, filename,
20 "(original)", "(refactored)",
21 lineterm="")
24 class StdoutRefactoringTool(refactor.MultiprocessRefactoringTool):
25 """
26 Prints output to stdout.
27 """
29 def __init__(self, fixers, options, explicit, nobackups, show_diffs):
30 self.nobackups = nobackups
31 self.show_diffs = show_diffs
32 super(StdoutRefactoringTool, self).__init__(fixers, options, explicit)
34 def log_error(self, msg, *args, **kwargs):
35 self.errors.append((msg, args, kwargs))
36 self.logger.error(msg, *args, **kwargs)
38 def write_file(self, new_text, filename, old_text, encoding):
39 if not self.nobackups:
40 # Make backup
41 backup = filename + ".bak"
42 if os.path.lexists(backup):
43 try:
44 os.remove(backup)
45 except os.error, err:
46 self.log_message("Can't remove backup %s", backup)
47 try:
48 os.rename(filename, backup)
49 except os.error, err:
50 self.log_message("Can't rename %s to %s", filename, backup)
51 # Actually write the new file
52 write = super(StdoutRefactoringTool, self).write_file
53 write(new_text, filename, old_text, encoding)
54 if not self.nobackups:
55 shutil.copymode(backup, filename)
57 def print_output(self, old, new, filename, equal):
58 if equal:
59 self.log_message("No changes to %s", filename)
60 else:
61 self.log_message("Refactored %s", filename)
62 if self.show_diffs:
63 for line in diff_texts(old, new, filename):
64 print line
67 def warn(msg):
68 print >> sys.stderr, "WARNING: %s" % (msg,)
71 def main(fixer_pkg, args=None):
72 """Main program.
74 Args:
75 fixer_pkg: the name of a package where the fixers are located.
76 args: optional; a list of command line arguments. If omitted,
77 sys.argv[1:] is used.
79 Returns a suggested exit status (0, 1, 2).
80 """
81 # Set up option parser
82 parser = optparse.OptionParser(usage="2to3 [options] file|dir ...")
83 parser.add_option("-d", "--doctests_only", action="store_true",
84 help="Fix up doctests only")
85 parser.add_option("-f", "--fix", action="append", default=[],
86 help="Each FIX specifies a transformation; default: all")
87 parser.add_option("-j", "--processes", action="store", default=1,
88 type="int", help="Run 2to3 concurrently")
89 parser.add_option("-x", "--nofix", action="append", default=[],
90 help="Prevent a fixer from being run.")
91 parser.add_option("-l", "--list-fixes", action="store_true",
92 help="List available transformations (fixes/fix_*.py)")
93 parser.add_option("-p", "--print-function", action="store_true",
94 help="Modify the grammar so that print() is a function")
95 parser.add_option("-v", "--verbose", action="store_true",
96 help="More verbose logging")
97 parser.add_option("--no-diffs", action="store_true",
98 help="Don't show diffs of the refactoring")
99 parser.add_option("-w", "--write", action="store_true",
100 help="Write back modified files")
101 parser.add_option("-n", "--nobackups", action="store_true", default=False,
102 help="Don't write backups for modified files.")
104 # Parse command line arguments
105 refactor_stdin = False
106 flags = {}
107 options, args = parser.parse_args(args)
108 if not options.write and options.no_diffs:
109 warn("not writing files and not printing diffs; that's not very useful")
110 if not options.write and options.nobackups:
111 parser.error("Can't use -n without -w")
112 if options.list_fixes:
113 print "Available transformations for the -f/--fix option:"
114 for fixname in refactor.get_all_fix_names(fixer_pkg):
115 print fixname
116 if not args:
117 return 0
118 if not args:
119 print >> sys.stderr, "At least one file or directory argument required."
120 print >> sys.stderr, "Use --help to show usage."
121 return 2
122 if "-" in args:
123 refactor_stdin = True
124 if options.write:
125 print >> sys.stderr, "Can't write to stdin."
126 return 2
127 if options.print_function:
128 flags["print_function"] = True
130 # Set up logging handler
131 level = logging.DEBUG if options.verbose else logging.INFO
132 logging.basicConfig(format='%(name)s: %(message)s', level=level)
134 # Initialize the refactoring tool
135 avail_fixes = set(refactor.get_fixers_from_package(fixer_pkg))
136 unwanted_fixes = set(fixer_pkg + ".fix_" + fix for fix in options.nofix)
137 explicit = set()
138 if options.fix:
139 all_present = False
140 for fix in options.fix:
141 if fix == "all":
142 all_present = True
143 else:
144 explicit.add(fixer_pkg + ".fix_" + fix)
145 requested = avail_fixes.union(explicit) if all_present else explicit
146 else:
147 requested = avail_fixes.union(explicit)
148 fixer_names = requested.difference(unwanted_fixes)
149 rt = StdoutRefactoringTool(sorted(fixer_names), flags, sorted(explicit),
150 options.nobackups, not options.no_diffs)
152 # Refactor all files and directories passed as arguments
153 if not rt.errors:
154 if refactor_stdin:
155 rt.refactor_stdin()
156 else:
157 try:
158 rt.refactor(args, options.write, options.doctests_only,
159 options.processes)
160 except refactor.MultiprocessingUnsupported:
161 assert options.processes > 1
162 print >> sys.stderr, "Sorry, -j isn't " \
163 "supported on this platform."
164 return 1
165 rt.summarize()
167 # Return error status (0 if rt.errors is zero)
168 return int(bool(rt.errors))