summaryrefslogtreecommitdiff
path: root/Lib/lib2to3/main.py
blob: 1a1df013ade3ea12806be22dec99785082ae1ccd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
"""
Main program for 2to3.
"""

from __future__ import with_statement, print_function

import sys
import os
import difflib
import logging
import shutil
import optparse

from . import refactor


def diff_texts(a, b, filename):
    """Return a unified diff of two strings."""
    a = a.splitlines()
    b = b.splitlines()
    return difflib.unified_diff(a, b, filename, filename,
                                "(original)", "(refactored)",
                                lineterm="")


class StdoutRefactoringTool(refactor.MultiprocessRefactoringTool):
    """
    A refactoring tool that can avoid overwriting its input files.
    Prints output to stdout.

    Output files can optionally be written to a different directory and or
    have an extra file suffix appended to their name for use in situations
    where you do not want to replace the input files.
    """

    def __init__(self, fixers, options, explicit, nobackups, show_diffs,
                 input_base_dir='', output_dir='', append_suffix=''):
        """
        Args:
            fixers: A list of fixers to import.
            options: A dict with RefactoringTool configuration.
            explicit: A list of fixers to run even if they are explicit.
            nobackups: If true no backup '.bak' files will be created for those
                files that are being refactored.
            show_diffs: Should diffs of the refactoring be printed to stdout?
            input_base_dir: The base directory for all input files.  This class
                will strip this path prefix off of filenames before substituting
                it with output_dir.  Only meaningful if output_dir is supplied.
                All files processed by refactor() must start with this path.
            output_dir: If supplied, all converted files will be written into
                this directory tree instead of input_base_dir.
            append_suffix: If supplied, all files output by this tool will have
                this appended to their filename.  Useful for changing .py to
                .py3 for example by passing append_suffix='3'.
        """
        self.nobackups = nobackups
        self.show_diffs = show_diffs
        if input_base_dir and not input_base_dir.endswith(os.sep):
            input_base_dir += os.sep
        self._input_base_dir = input_base_dir
        self._output_dir = output_dir
        self._append_suffix = append_suffix
        super(StdoutRefactoringTool, self).__init__(fixers, options, explicit)

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

    def write_file(self, new_text, filename, old_text, encoding):
        orig_filename = filename
        if self._output_dir:
            if filename.startswith(self._input_base_dir):
                filename = os.path.join(self._output_dir,
                                        filename[len(self._input_base_dir):])
            else:
                raise ValueError('filename %s does not start with the '
                                 'input_base_dir %s' % (
                                         filename, self._input_base_dir))
        if self._append_suffix:
            filename += self._append_suffix
        if orig_filename != filename:
            output_dir = os.path.dirname(filename)
            if not os.path.isdir(output_dir):
                os.makedirs(output_dir)
            self.log_message('Writing converted %s to %s.', orig_filename,
                             filename)
        if not self.nobackups:
            # Make backup
            backup = filename + ".bak"
            if os.path.lexists(backup):
                try:
                    os.remove(backup)
                except OSError as err:
                    self.log_message("Can't remove backup %s", backup)
            try:
                os.rename(filename, backup)
            except OSError as err:
                self.log_message("Can't rename %s to %s", filename, backup)
        # Actually write the new file
        write = super(StdoutRefactoringTool, self).write_file
        write(new_text, filename, old_text, encoding)
        if not self.nobackups:
            shutil.copymode(backup, filename)
        if orig_filename != filename:
            # Preserve the file mode in the new output directory.
            shutil.copymode(orig_filename, filename)

    def print_output(self, old, new, filename, equal):
        if equal:
            self.log_message("No changes to %s", filename)
        else:
            self.log_message("Refactored %s", filename)
            if self.show_diffs:
                diff_lines = diff_texts(old, new, filename)
                try:
                    if self.output_lock is not None:
                        with self.output_lock:
                            for line in diff_lines:
                                print(line)
                            sys.stdout.flush()
                    else:
                        for line in diff_lines:
                            print(line)
                except UnicodeEncodeError:
                    warn("couldn't encode %s's diff for your terminal" %
                         (filename,))
                    return

def warn(msg):
    print("WARNING: %s" % (msg,), file=sys.stderr)


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="2to3 [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("-j", "--processes", action="store", default=1,
                      type="int", help="Run 2to3 concurrently")
    parser.add_option("-x", "--nofix", action="append", default=[],
                      help="Prevent a transformation from being run")
    parser.add_option("-l", "--list-fixes", action="store_true",
                      help="List available transformations")
    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("--no-diffs", action="store_true",
                      help="Don't show diffs of the refactoring")
    parser.add_option("-w", "--write", action="store_true",
                      help="Write back modified files")
    parser.add_option("-n", "--nobackups", action="store_true", default=False,
                      help="Don't write backups for modified files")
    parser.add_option("-o", "--output-dir", action="store", type="str",
                      default="", help="Put output files in this directory "
                      "instead of overwriting the input files.  Requires -n.")
    parser.add_option("-W", "--write-unchanged-files", action="store_true",
                      help="Also write files even if no changes were required"
                      " (useful with --output-dir); implies -w.")
    parser.add_option("--add-suffix", action="store", type="str", default="",
                      help="Append this string to all output filenames."
                      " Requires -n if non-empty.  "
                      "ex: --add-suffix='3' will generate .py3 files.")

    # Parse command line arguments
    refactor_stdin = False
    flags = {}
    options, args = parser.parse_args(args)
    if options.write_unchanged_files:
        flags["write_unchanged_files"] = True
        if not options.write:
            warn("--write-unchanged-files/-W implies -w.")
        options.write = True
    # If we allowed these, the original files would be renamed to backup names
    # but not replaced.
    if options.output_dir and not options.nobackups:
        parser.error("Can't use --output-dir/-o without -n.")
    if options.add_suffix and not options.nobackups:
        parser.error("Can't use --add-suffix without -n.")

    if not options.write and options.no_diffs:
        warn("not writing files and not printing diffs; that's not very useful")
    if not options.write and options.nobackups:
        parser.error("Can't use -n without -w")
    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
    if options.print_function:
        flags["print_function"] = True

    # Set up logging handler
    level = logging.DEBUG if options.verbose else logging.INFO
    logging.basicConfig(format='%(name)s: %(message)s', level=level)
    logger = logging.getLogger('lib2to3.main')

    # Initialize the refactoring tool
    avail_fixes = set(refactor.get_fixers_from_package(fixer_pkg))
    unwanted_fixes = set(fixer_pkg + ".fix_" + fix for fix in options.nofix)
    explicit = set()
    if options.fix:
        all_present = False
        for fix in options.fix:
            if fix == "all":
                all_present = True
            else:
                explicit.add(fixer_pkg + ".fix_" + fix)
        requested = avail_fixes.union(explicit) if all_present else explicit
    else:
        requested = avail_fixes.union(explicit)
    fixer_names = requested.difference(unwanted_fixes)
    input_base_dir = os.path.commonprefix(args)
    if (input_base_dir and not input_base_dir.endswith(os.sep)
        and not os.path.isdir(input_base_dir)):
        # One or more similar names were passed, their directory is the base.
        # os.path.commonprefix() is ignorant of path elements, this corrects
        # for that weird API.
        input_base_dir = os.path.dirname(input_base_dir)
    if options.output_dir:
        input_base_dir = input_base_dir.rstrip(os.sep)
        logger.info('Output in %r will mirror the input directory %r layout.',
                    options.output_dir, input_base_dir)
    rt = StdoutRefactoringTool(
            sorted(fixer_names), flags, sorted(explicit),
            options.nobackups, not options.no_diffs,
            input_base_dir=input_base_dir,
            output_dir=options.output_dir,
            append_suffix=options.add_suffix)

    # Refactor all files and directories passed as arguments
    if not rt.errors:
        if refactor_stdin:
            rt.refactor_stdin()
        else:
            try:
                rt.refactor(args, options.write, options.doctests_only,
                            options.processes)
            except refactor.MultiprocessingUnsupported:
                assert options.processes > 1
                print("Sorry, -j isn't supported on this platform.",
                      file=sys.stderr)
                return 1
        rt.summarize()

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