Add google-endpoints to third_party/.

third_party/google-endpoints/libfuturize/main.py

+"""
+futurize: automatic conversion to clean 2/3 code using ``python-future``
+======================================================================
+
+Like Armin Ronacher's modernize.py, ``futurize`` attempts to produce clean
+standard Python 3 code that runs on both Py2 and Py3.
+
+One pass
+--------
+
+Use it like this on Python 2 code:
+
+  $ futurize --verbose mypython2script.py
+
+This will attempt to port the code to standard Py3 code that also
+provides Py2 compatibility with the help of the right imports from
+``future``.
+
+To write changes to the files, use the -w flag.
+
+Two stages
+----------
+
+The ``futurize`` script can also be called in two separate stages. First:
+
+  $ futurize --stage1 mypython2script.py
+
+This produces more modern Python 2 code that is not yet compatible with Python
+3. The tests should still run and the diff should be uncontroversial to apply to
+most Python projects that are willing to drop support for Python 2.5 and lower.
+
+After this, the recommended approach is to explicitly mark all strings that must
+be byte-strings with a b'' prefix and all text (unicode) strings with a u''
+prefix, and then invoke the second stage of Python 2 to 2/3 conversion with::
+
+  $ futurize --stage2 mypython2script.py
+
+Stage 2 adds a dependency on ``future``. It converts most remaining Python
+2-specific code to Python 3 code and adds appropriate imports from ``future``
+to restore Py2 support.
+
+The command above leaves all unadorned string literals as native strings
+(byte-strings on Py2, unicode strings on Py3). If instead you would like all
+unadorned string literals to be promoted to unicode, you can also pass this
+flag:
+
+  $ futurize --stage2 --unicode-literals mypython2script.py
+
+This adds the declaration ``from __future__ import unicode_literals`` to the
+top of each file, which implicitly declares all unadorned string literals to be
+unicode strings (``unicode`` on Py2).
+
+All imports
+-----------
+
+The --all-imports option forces adding all ``__future__`` imports,
+``builtins`` imports, and standard library aliases, even if they don't
+seem necessary for the current state of each module. (This can simplify
+testing, and can reduce the need to think about Py2 compatibility when editing
+the code further.)
+
+"""
+
+from __future__ import (absolute_import, print_function, unicode_literals)
+import future.utils
+from future import __version__
+
+import sys
+import logging
+import optparse
+import os
+
+from lib2to3.main import main, warn, StdoutRefactoringTool
+from lib2to3 import refactor
+
+from libfuturize.fixes import (lib2to3_fix_names_stage1,
+                               lib2to3_fix_names_stage2,
+                               libfuturize_fix_names_stage1,
+                               libfuturize_fix_names_stage2)
+
+fixer_pkg = 'libfuturize.fixes'
+
+
+def main(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="futurize [options] file|dir ...")
+    parser.add_option("-V", "--version", action="store_true",
+                      help="Report the version number of futurize")
+    parser.add_option("-a", "--all-imports", action="store_true",
+                      help="Add all __future__ and future imports to each module")
+    parser.add_option("-1", "--stage1", action="store_true",
+                      help="Modernize Python 2 code only; no compatibility with Python 3 (or dependency on ``future``)")
+    parser.add_option("-2", "--stage2", action="store_true",
+                      help="Take modernized (stage1) code and add a dependency on ``future`` to provide Py3 compatibility.")
+    parser.add_option("-0", "--both-stages", action="store_true",
+                      help="Apply both stages 1 and 2")
+    parser.add_option("-u", "--unicode-literals", action="store_true",
+                      help="Add ``from __future__ import unicode_literals`` to implicitly convert all unadorned string literals '' into unicode strings")
+    parser.add_option("-f", "--fix", action="append", default=[],
+                      help="Each FIX specifies a transformation; default: all.\nEither use '-f division -f metaclass' etc. or use the fully-qualified module name: '-f lib2to3.fixes.fix_types -f libfuturize.fixes.fix_unicode_keep_u'")
+    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 fixer 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. "
+                      "For Python >= 2.7 only.")
+    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. For Python >= 2.7 only."
+                      "ex: --add-suffix='3' will generate .py3 files.")
+
+    # Parse command line arguments
+    flags = {}
+    refactor_stdin = False
+    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 "-" in args:
+        refactor_stdin = True
+        if options.write:
+            print("Can't write to stdin.", file=sys.stderr)
+            return 2
+    # Is this ever necessary?
+    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('libfuturize.main')
+
+    if options.stage1 or options.stage2:
+        assert options.both_stages is None
+        options.both_stages = False
+    else:
+        options.both_stages = True
+
+    avail_fixes = set()
+
+    if options.stage1 or options.both_stages:
+        avail_fixes.update(lib2to3_fix_names_stage1)
+        avail_fixes.update(libfuturize_fix_names_stage1)
+    if options.stage2 or options.both_stages:
+        avail_fixes.update(lib2to3_fix_names_stage2)
+        avail_fixes.update(libfuturize_fix_names_stage2)
+
+    if options.unicode_literals:
+        avail_fixes.add('libfuturize.fixes.fix_unicode_literals_import')
+
+    if options.version:
+        print(__version__)
+        return 0
+    if options.list_fixes:
+        print("Available transformations for the -f/--fix option:")
+        # for fixname in sorted(refactor.get_all_fix_names(fixer_pkg)):
+        for fixname in sorted(avail_fixes):
+            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
+
+    unwanted_fixes = set(fixer_pkg + ".fix_" + fix for fix in options.nofix)
+
+    extra_fixes = set()
+    if options.all_imports:
+        if options.stage1:
+            prefix = 'libfuturize.fixes.'
+            extra_fixes.add(prefix +
+                            'fix_add__future__imports_except_unicode_literals')
+        else:
+            # In case the user hasn't run stage1 for some reason:
+            prefix = 'libpasteurize.fixes.'
+            extra_fixes.add(prefix + 'fix_add_all__future__imports')
+            extra_fixes.add(prefix + 'fix_add_future_standard_library_import')
+            extra_fixes.add(prefix + 'fix_add_all_future_builtins')
+    explicit = set()
+    if options.fix:
+        all_present = False
+        for fix in options.fix:
+            if fix == 'all':
+                all_present = True
+            else:
+                if ".fix_" in fix:
+                    explicit.add(fix)
+                else:
+                    # Infer the full module name for the fixer.
+                    # First ensure that no names clash (e.g.
+                    # lib2to3.fixes.fix_blah and libfuturize.fixes.fix_blah):
+                    found = [f for f in avail_fixes
+                             if f.endswith('fix_{0}'.format(fix))]
+                    if len(found) > 1:
+                        print("Ambiguous fixer name. Choose a fully qualified "
+                              "module name instead from these:\n" +
+                              "\n".join("  " + myf for myf in found),
+                              file=sys.stderr)
+                        return 2
+                    elif len(found) == 0:
+                        print("Unknown fixer. Use --list-fixes or -l for a list.",
+                              file=sys.stderr)
+                        return 2
+                    explicit.add(found[0])
+        if len(explicit & unwanted_fixes) > 0:
+            print("Conflicting usage: the following fixers have been "
+                  "simultaneously requested and disallowed:\n" +
+                  "\n".join("  " + myf for myf in (explicit & unwanted_fixes)),
+                  file=sys.stderr)
+            return 2
+        requested = avail_fixes.union(explicit) if all_present else explicit
+    else:
+        requested = avail_fixes.union(explicit)
+    fixer_names = (requested | extra_fixes) - 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)
+
+    # Initialize the refactoring tool
+    if future.utils.PY26:
+        extra_kwargs = {}
+    else:
+        extra_kwargs = {
+                        'append_suffix': options.add_suffix,
+                        'output_dir': options.output_dir,
+                        'input_base_dir': input_base_dir,
+                       }
+
+    rt = StdoutRefactoringTool(
+            sorted(fixer_names), flags, sorted(explicit),
+            options.nobackups, not options.no_diffs,
+            **extra_kwargs)
+
+    # 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, None,
+                            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))