| Index: third_party/pylint/checkers/strings.py
 | 
| diff --git a/third_party/pylint/checkers/strings.py b/third_party/pylint/checkers/strings.py
 | 
| deleted file mode 100644
 | 
| index 0eda6a2cb60891773621a8a99508bb21ecdd53cd..0000000000000000000000000000000000000000
 | 
| --- a/third_party/pylint/checkers/strings.py
 | 
| +++ /dev/null
 | 
| @@ -1,619 +0,0 @@
 | 
| -# Copyright (c) 2009-2010 Arista Networks, Inc. - James Lingard
 | 
| -# Copyright (c) 2004-2013 LOGILAB S.A. (Paris, FRANCE).
 | 
| -# Copyright 2012 Google Inc.
 | 
| -#
 | 
| -# http://www.logilab.fr/ -- mailto:contact@logilab.fr
 | 
| -# This program is free software; you can redistribute it and/or modify it under
 | 
| -# the terms of the GNU General Public License as published by the Free Software
 | 
| -# Foundation; either version 2 of the License, or (at your option) any later
 | 
| -# version.
 | 
| -#
 | 
| -# This program is distributed in the hope that it will be useful, but WITHOUT
 | 
| -# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 | 
| -# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details
 | 
| -#
 | 
| -# You should have received a copy of the GNU General Public License along with
 | 
| -# this program; if not, write to the Free Software Foundation, Inc.,
 | 
| -# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 | 
| -"""Checker for string formatting operations.
 | 
| -"""
 | 
| -
 | 
| -import sys
 | 
| -import tokenize
 | 
| -import string
 | 
| -try:
 | 
| -    import numbers
 | 
| -except ImportError:
 | 
| -    numbers = None
 | 
| -
 | 
| -import astroid
 | 
| -
 | 
| -from pylint.interfaces import ITokenChecker, IAstroidChecker, IRawChecker
 | 
| -from pylint.checkers import BaseChecker, BaseTokenChecker
 | 
| -from pylint.checkers import utils
 | 
| -from pylint.checkers.utils import check_messages
 | 
| -
 | 
| -_PY3K = sys.version_info[:2] >= (3, 0)
 | 
| -_PY27 = sys.version_info[:2] == (2, 7)
 | 
| -
 | 
| -MSGS = {
 | 
| -    'E1300': ("Unsupported format character %r (%#02x) at index %d",
 | 
| -              "bad-format-character",
 | 
| -              "Used when a unsupported format character is used in a format\
 | 
| -              string."),
 | 
| -    'E1301': ("Format string ends in middle of conversion specifier",
 | 
| -              "truncated-format-string",
 | 
| -              "Used when a format string terminates before the end of a \
 | 
| -              conversion specifier."),
 | 
| -    'E1302': ("Mixing named and unnamed conversion specifiers in format string",
 | 
| -              "mixed-format-string",
 | 
| -              "Used when a format string contains both named (e.g. '%(foo)d') \
 | 
| -              and unnamed (e.g. '%d') conversion specifiers.  This is also \
 | 
| -              used when a named conversion specifier contains * for the \
 | 
| -              minimum field width and/or precision."),
 | 
| -    'E1303': ("Expected mapping for format string, not %s",
 | 
| -              "format-needs-mapping",
 | 
| -              "Used when a format string that uses named conversion specifiers \
 | 
| -              is used with an argument that is not a mapping."),
 | 
| -    'W1300': ("Format string dictionary key should be a string, not %s",
 | 
| -              "bad-format-string-key",
 | 
| -              "Used when a format string that uses named conversion specifiers \
 | 
| -              is used with a dictionary whose keys are not all strings."),
 | 
| -    'W1301': ("Unused key %r in format string dictionary",
 | 
| -              "unused-format-string-key",
 | 
| -              "Used when a format string that uses named conversion specifiers \
 | 
| -              is used with a dictionary that conWtains keys not required by the \
 | 
| -              format string."),
 | 
| -    'E1304': ("Missing key %r in format string dictionary",
 | 
| -              "missing-format-string-key",
 | 
| -              "Used when a format string that uses named conversion specifiers \
 | 
| -              is used with a dictionary that doesn't contain all the keys \
 | 
| -              required by the format string."),
 | 
| -    'E1305': ("Too many arguments for format string",
 | 
| -              "too-many-format-args",
 | 
| -              "Used when a format string that uses unnamed conversion \
 | 
| -              specifiers is given too many arguments."),
 | 
| -    'E1306': ("Not enough arguments for format string",
 | 
| -              "too-few-format-args",
 | 
| -              "Used when a format string that uses unnamed conversion \
 | 
| -              specifiers is given too few arguments"),
 | 
| -
 | 
| -    'W1302': ("Invalid format string",
 | 
| -              "bad-format-string",
 | 
| -              "Used when a PEP 3101 format string is invalid.",
 | 
| -              {'minversion': (2, 7)}),
 | 
| -    'W1303': ("Missing keyword argument %r for format string",
 | 
| -              "missing-format-argument-key",
 | 
| -              "Used when a PEP 3101 format string that uses named fields "
 | 
| -              "doesn't receive one or more required keywords.",
 | 
| -              {'minversion': (2, 7)}),
 | 
| -    'W1304': ("Unused format argument %r",
 | 
| -              "unused-format-string-argument",
 | 
| -              "Used when a PEP 3101 format string that uses named "
 | 
| -              "fields is used with an argument that "
 | 
| -              "is not required by the format string.",
 | 
| -              {'minversion': (2, 7)}),
 | 
| -    'W1305': ("Format string contains both automatic field numbering "
 | 
| -              "and manual field specification",
 | 
| -              "format-combined-specification",
 | 
| -              "Usen when a PEP 3101 format string contains both automatic "
 | 
| -              "field numbering (e.g. '{}') and manual field "
 | 
| -              "specification (e.g. '{0}').",
 | 
| -              {'minversion': (2, 7)}),
 | 
| -    'W1306': ("Missing format attribute %r in format specifier %r",
 | 
| -              "missing-format-attribute",
 | 
| -              "Used when a PEP 3101 format string uses an "
 | 
| -              "attribute specifier ({0.length}), but the argument "
 | 
| -              "passed for formatting doesn't have that attribute.",
 | 
| -              {'minversion': (2, 7)}),
 | 
| -    'W1307': ("Using invalid lookup key %r in format specifier %r",
 | 
| -              "invalid-format-index",
 | 
| -              "Used when a PEP 3101 format string uses a lookup specifier "
 | 
| -              "({a[1]}), but the argument passed for formatting "
 | 
| -              "doesn't contain or doesn't have that key as an attribute.",
 | 
| -              {'minversion': (2, 7)})
 | 
| -    }
 | 
| -
 | 
| -OTHER_NODES = (astroid.Const, astroid.List, astroid.Backquote,
 | 
| -               astroid.Lambda, astroid.Function,
 | 
| -               astroid.ListComp, astroid.SetComp, astroid.GenExpr)
 | 
| -
 | 
| -if _PY3K:
 | 
| -    import _string
 | 
| -
 | 
| -    def split_format_field_names(format_string):
 | 
| -        return _string.formatter_field_name_split(format_string)
 | 
| -else:
 | 
| -    def _field_iterator_convertor(iterator):
 | 
| -        for is_attr, key in iterator:
 | 
| -            if isinstance(key, numbers.Number):
 | 
| -                yield is_attr, int(key)
 | 
| -            else:
 | 
| -                yield is_attr, key
 | 
| -
 | 
| -    def split_format_field_names(format_string):
 | 
| -        keyname, fielditerator = format_string._formatter_field_name_split()
 | 
| -        # it will return longs, instead of ints, which will complicate
 | 
| -        # the output
 | 
| -        return keyname, _field_iterator_convertor(fielditerator)
 | 
| -
 | 
| -
 | 
| -def collect_string_fields(format_string):
 | 
| -    """ Given a format string, return an iterator
 | 
| -    of all the valid format fields. It handles nested fields
 | 
| -    as well.
 | 
| -    """
 | 
| -
 | 
| -    formatter = string.Formatter()
 | 
| -    parseiterator = formatter.parse(format_string)
 | 
| -    try:
 | 
| -        for result in parseiterator:
 | 
| -            if all(item is None for item in result[1:]):
 | 
| -                # not a replacement format
 | 
| -                continue
 | 
| -            name = result[1]
 | 
| -            nested = result[2]
 | 
| -            yield name
 | 
| -            if nested:
 | 
| -                for field in collect_string_fields(nested):
 | 
| -                    yield field
 | 
| -    except ValueError:
 | 
| -        # probably the format string is invalid
 | 
| -        # should we check the argument of the ValueError?
 | 
| -        raise utils.IncompleteFormatString(format_string)
 | 
| -
 | 
| -def parse_format_method_string(format_string):
 | 
| -    """
 | 
| -    Parses a PEP 3101 format string, returning a tuple of
 | 
| -    (keys, num_args, manual_pos_arg),
 | 
| -    where keys is the set of mapping keys in the format string, num_args
 | 
| -    is the number of arguments required by the format string and
 | 
| -    manual_pos_arg is the number of arguments passed with the position.
 | 
| -    """
 | 
| -    keys = []
 | 
| -    num_args = 0
 | 
| -    manual_pos_arg = set()
 | 
| -    for name in collect_string_fields(format_string):
 | 
| -        if name and str(name).isdigit():
 | 
| -            manual_pos_arg.add(str(name))
 | 
| -        elif name:
 | 
| -            keyname, fielditerator = split_format_field_names(name)
 | 
| -            if isinstance(keyname, numbers.Number):
 | 
| -                # In Python 2 it will return long which will lead
 | 
| -                # to different output between 2 and 3
 | 
| -                keyname = int(keyname)
 | 
| -            keys.append((keyname, list(fielditerator)))
 | 
| -        else:
 | 
| -            num_args += 1
 | 
| -    return keys, num_args, len(manual_pos_arg)
 | 
| -
 | 
| -def get_args(callfunc):
 | 
| -    """ Get the arguments from the given `CallFunc` node.
 | 
| -    Return a tuple, where the first element is the
 | 
| -    number of positional arguments and the second element
 | 
| -    is the keyword arguments in a dict.
 | 
| -    """
 | 
| -    positional = 0
 | 
| -    named = {}
 | 
| -
 | 
| -    for arg in callfunc.args:
 | 
| -        if isinstance(arg, astroid.Keyword):
 | 
| -            named[arg.arg] = utils.safe_infer(arg.value)
 | 
| -        else:
 | 
| -            positional += 1
 | 
| -    return positional, named
 | 
| -
 | 
| -def get_access_path(key, parts):
 | 
| -    """ Given a list of format specifiers, returns
 | 
| -    the final access path (e.g. a.b.c[0][1]).
 | 
| -    """
 | 
| -    path = []
 | 
| -    for is_attribute, specifier in parts:
 | 
| -        if is_attribute:
 | 
| -            path.append(".{}".format(specifier))
 | 
| -        else:
 | 
| -            path.append("[{!r}]".format(specifier))
 | 
| -    return str(key) + "".join(path)
 | 
| -
 | 
| -
 | 
| -class StringFormatChecker(BaseChecker):
 | 
| -    """Checks string formatting operations to ensure that the format string
 | 
| -    is valid and the arguments match the format string.
 | 
| -    """
 | 
| -
 | 
| -    __implements__ = (IAstroidChecker,)
 | 
| -    name = 'string'
 | 
| -    msgs = MSGS
 | 
| -
 | 
| -    @check_messages(*(MSGS.keys()))
 | 
| -    def visit_binop(self, node):
 | 
| -        if node.op != '%':
 | 
| -            return
 | 
| -        left = node.left
 | 
| -        args = node.right
 | 
| -
 | 
| -        if not (isinstance(left, astroid.Const)
 | 
| -                and isinstance(left.value, basestring)):
 | 
| -            return
 | 
| -        format_string = left.value
 | 
| -        try:
 | 
| -            required_keys, required_num_args = \
 | 
| -                utils.parse_format_string(format_string)
 | 
| -        except utils.UnsupportedFormatCharacter, e:
 | 
| -            c = format_string[e.index]
 | 
| -            self.add_message('bad-format-character',
 | 
| -                             node=node, args=(c, ord(c), e.index))
 | 
| -            return
 | 
| -        except utils.IncompleteFormatString:
 | 
| -            self.add_message('truncated-format-string', node=node)
 | 
| -            return
 | 
| -        if required_keys and required_num_args:
 | 
| -            # The format string uses both named and unnamed format
 | 
| -            # specifiers.
 | 
| -            self.add_message('mixed-format-string', node=node)
 | 
| -        elif required_keys:
 | 
| -            # The format string uses only named format specifiers.
 | 
| -            # Check that the RHS of the % operator is a mapping object
 | 
| -            # that contains precisely the set of keys required by the
 | 
| -            # format string.
 | 
| -            if isinstance(args, astroid.Dict):
 | 
| -                keys = set()
 | 
| -                unknown_keys = False
 | 
| -                for k, _ in args.items:
 | 
| -                    if isinstance(k, astroid.Const):
 | 
| -                        key = k.value
 | 
| -                        if isinstance(key, basestring):
 | 
| -                            keys.add(key)
 | 
| -                        else:
 | 
| -                            self.add_message('bad-format-string-key',
 | 
| -                                             node=node, args=key)
 | 
| -                    else:
 | 
| -                        # One of the keys was something other than a
 | 
| -                        # constant.  Since we can't tell what it is,
 | 
| -                        # supress checks for missing keys in the
 | 
| -                        # dictionary.
 | 
| -                        unknown_keys = True
 | 
| -                if not unknown_keys:
 | 
| -                    for key in required_keys:
 | 
| -                        if key not in keys:
 | 
| -                            self.add_message('missing-format-string-key',
 | 
| -                                             node=node, args=key)
 | 
| -                for key in keys:
 | 
| -                    if key not in required_keys:
 | 
| -                        self.add_message('unused-format-string-key',
 | 
| -                                         node=node, args=key)
 | 
| -            elif isinstance(args, OTHER_NODES + (astroid.Tuple,)):
 | 
| -                type_name = type(args).__name__
 | 
| -                self.add_message('format-needs-mapping',
 | 
| -                                 node=node, args=type_name)
 | 
| -            # else:
 | 
| -                # The RHS of the format specifier is a name or
 | 
| -                # expression.  It may be a mapping object, so
 | 
| -                # there's nothing we can check.
 | 
| -        else:
 | 
| -            # The format string uses only unnamed format specifiers.
 | 
| -            # Check that the number of arguments passed to the RHS of
 | 
| -            # the % operator matches the number required by the format
 | 
| -            # string.
 | 
| -            if isinstance(args, astroid.Tuple):
 | 
| -                num_args = len(args.elts)
 | 
| -            elif isinstance(args, OTHER_NODES + (astroid.Dict, astroid.DictComp)):
 | 
| -                num_args = 1
 | 
| -            else:
 | 
| -                # The RHS of the format specifier is a name or
 | 
| -                # expression.  It could be a tuple of unknown size, so
 | 
| -                # there's nothing we can check.
 | 
| -                num_args = None
 | 
| -            if num_args is not None:
 | 
| -                if num_args > required_num_args:
 | 
| -                    self.add_message('too-many-format-args', node=node)
 | 
| -                elif num_args < required_num_args:
 | 
| -                    self.add_message('too-few-format-args', node=node)
 | 
| -
 | 
| -
 | 
| -class StringMethodsChecker(BaseChecker):
 | 
| -    __implements__ = (IAstroidChecker,)
 | 
| -    name = 'string'
 | 
| -    msgs = {
 | 
| -        'E1310': ("Suspicious argument in %s.%s call",
 | 
| -                  "bad-str-strip-call",
 | 
| -                  "The argument to a str.{l,r,}strip call contains a"
 | 
| -                  " duplicate character, "),
 | 
| -        }
 | 
| -
 | 
| -    @check_messages(*(MSGS.keys()))
 | 
| -    def visit_callfunc(self, node):
 | 
| -        func = utils.safe_infer(node.func)
 | 
| -        if (isinstance(func, astroid.BoundMethod)
 | 
| -                and isinstance(func.bound, astroid.Instance)
 | 
| -                and func.bound.name in ('str', 'unicode', 'bytes')):
 | 
| -            if func.name in ('strip', 'lstrip', 'rstrip') and node.args:
 | 
| -                arg = utils.safe_infer(node.args[0])
 | 
| -                if not isinstance(arg, astroid.Const):
 | 
| -                    return
 | 
| -                if len(arg.value) != len(set(arg.value)):
 | 
| -                    self.add_message('bad-str-strip-call', node=node,
 | 
| -                                     args=(func.bound.name, func.name))
 | 
| -            elif func.name == 'format':
 | 
| -                if _PY27 or _PY3K:
 | 
| -                    self._check_new_format(node, func)
 | 
| -
 | 
| -    def _check_new_format(self, node, func):
 | 
| -        """ Check the new string formatting. """
 | 
| -        # TODO: skip (for now) format nodes which don't have
 | 
| -        #       an explicit string on the left side of the format operation.
 | 
| -        #       We do this because our inference engine can't properly handle
 | 
| -        #       redefinitions of the original string.
 | 
| -        #       For more details, see issue 287.
 | 
| -        if not isinstance(node.func.expr, astroid.Const):
 | 
| -            return
 | 
| -        try:
 | 
| -            strnode = func.bound.infer().next()
 | 
| -        except astroid.InferenceError:
 | 
| -            return
 | 
| -        if not isinstance(strnode, astroid.Const):
 | 
| -            return
 | 
| -        if node.starargs or node.kwargs:
 | 
| -            # TODO: Don't complicate the logic, skip these for now.
 | 
| -            return
 | 
| -        try:
 | 
| -            positional, named = get_args(node)
 | 
| -        except astroid.InferenceError:
 | 
| -            return
 | 
| -        try:
 | 
| -            fields, num_args, manual_pos = parse_format_method_string(strnode.value)
 | 
| -        except utils.IncompleteFormatString:
 | 
| -            self.add_message('bad-format-string', node=node)
 | 
| -            return
 | 
| -
 | 
| -        manual_fields = set(field[0] for field in fields
 | 
| -                            if isinstance(field[0], numbers.Number))
 | 
| -        named_fields = set(field[0] for field in fields
 | 
| -                           if isinstance(field[0], basestring))
 | 
| -        if num_args and manual_pos:
 | 
| -            self.add_message('format-combined-specification',
 | 
| -                             node=node)
 | 
| -            return
 | 
| -
 | 
| -        check_args = False
 | 
| -        # Consider "{[0]} {[1]}" as num_args.
 | 
| -        num_args += sum(1 for field in named_fields
 | 
| -                        if field == '')
 | 
| -        if named_fields:
 | 
| -            for field in named_fields:
 | 
| -                if field not in named and field:
 | 
| -                    self.add_message('missing-format-argument-key',
 | 
| -                                     node=node,
 | 
| -                                     args=(field, ))
 | 
| -            for field in named:
 | 
| -                if field not in named_fields:
 | 
| -                    self.add_message('unused-format-string-argument',
 | 
| -                                     node=node,
 | 
| -                                     args=(field, ))
 | 
| -            # num_args can be 0 if manual_pos is not.
 | 
| -            num_args = num_args or manual_pos
 | 
| -            if positional or num_args:
 | 
| -                empty = any(True for field in named_fields
 | 
| -                            if field == '')
 | 
| -                if named or empty:
 | 
| -                    # Verify the required number of positional arguments
 | 
| -                    # only if the .format got at least one keyword argument.
 | 
| -                    # This means that the format strings accepts both
 | 
| -                    # positional and named fields and we should warn
 | 
| -                    # when one of the them is missing or is extra.
 | 
| -                    check_args = True
 | 
| -        else:
 | 
| -            check_args = True
 | 
| -        if check_args:
 | 
| -            # num_args can be 0 if manual_pos is not.
 | 
| -            num_args = num_args or manual_pos
 | 
| -            if positional > num_args:
 | 
| -                # We can have two possibilities:
 | 
| -                # * "{0} {1}".format(a, b)
 | 
| -                # * "{} {} {}".format(a, b, c, d)
 | 
| -                # We can check the manual keys for the first one.
 | 
| -                if len(manual_fields) != positional:
 | 
| -                    self.add_message('too-many-format-args', node=node)
 | 
| -            elif positional < num_args:
 | 
| -                self.add_message('too-few-format-args', node=node)
 | 
| -
 | 
| -        self._check_new_format_specifiers(node, fields, named)
 | 
| -
 | 
| -    def _check_new_format_specifiers(self, node, fields, named):
 | 
| -        """
 | 
| -        Check attribute and index access in the format
 | 
| -        string ("{0.a}" and "{0[a]}").
 | 
| -        """
 | 
| -        for key, specifiers in fields:
 | 
| -            # Obtain the argument. If it can't be obtained
 | 
| -            # or infered, skip this check.
 | 
| -            if key == '':
 | 
| -                # {[0]} will have an unnamed argument, defaulting
 | 
| -                # to 0. It will not be present in `named`, so use the value
 | 
| -                # 0 for it.
 | 
| -                key = 0
 | 
| -            if isinstance(key, numbers.Number):
 | 
| -                try:
 | 
| -                    argname = utils.get_argument_from_call(node, key)
 | 
| -                except utils.NoSuchArgumentError:
 | 
| -                    continue
 | 
| -            else:
 | 
| -                if key not in named:
 | 
| -                    continue
 | 
| -                argname = named[key]
 | 
| -            if argname in (astroid.YES, None):
 | 
| -                continue
 | 
| -            try:
 | 
| -                argument = argname.infer().next()
 | 
| -            except astroid.InferenceError:
 | 
| -                continue
 | 
| -            if not specifiers or argument is astroid.YES:
 | 
| -                # No need to check this key if it doesn't
 | 
| -                # use attribute / item access
 | 
| -                continue
 | 
| -            if argument.parent and isinstance(argument.parent, astroid.Arguments):
 | 
| -                # Check to see if our argument is kwarg or vararg,
 | 
| -                # and skip the check for this argument if so, because when inferring,
 | 
| -                # astroid will return empty objects (dicts and tuples) and
 | 
| -                # that can lead to false positives.
 | 
| -                if argname.name in (argument.parent.kwarg, argument.parent.vararg):
 | 
| -                    continue
 | 
| -            previous = argument
 | 
| -            parsed = []
 | 
| -            for is_attribute, specifier in specifiers:
 | 
| -                if previous is astroid.YES:
 | 
| -                    break
 | 
| -                parsed.append((is_attribute, specifier))
 | 
| -                if is_attribute:
 | 
| -                    try:
 | 
| -                        previous = previous.getattr(specifier)[0]
 | 
| -                    except astroid.NotFoundError:
 | 
| -                        if (hasattr(previous, 'has_dynamic_getattr') and
 | 
| -                                previous.has_dynamic_getattr()):
 | 
| -                            # Don't warn if the object has a custom __getattr__
 | 
| -                            break
 | 
| -                        path = get_access_path(key, parsed)
 | 
| -                        self.add_message('missing-format-attribute',
 | 
| -                                         args=(specifier, path),
 | 
| -                                         node=node)
 | 
| -                        break
 | 
| -                else:
 | 
| -                    warn_error = False
 | 
| -                    if hasattr(previous, 'getitem'):
 | 
| -                        try:
 | 
| -                            previous = previous.getitem(specifier)
 | 
| -                        except (IndexError, TypeError):
 | 
| -                            warn_error = True
 | 
| -                    else:
 | 
| -                        try:
 | 
| -                            # Lookup __getitem__ in the current node,
 | 
| -                            # but skip further checks, because we can't
 | 
| -                            # retrieve the looked object
 | 
| -                            previous.getattr('__getitem__')
 | 
| -                            break
 | 
| -                        except astroid.NotFoundError:
 | 
| -                            warn_error = True
 | 
| -                    if warn_error:
 | 
| -                        path = get_access_path(key, parsed)
 | 
| -                        self.add_message('invalid-format-index',
 | 
| -                                         args=(specifier, path),
 | 
| -                                         node=node)
 | 
| -                        break
 | 
| -
 | 
| -                try:
 | 
| -                    previous = previous.infer().next()
 | 
| -                except astroid.InferenceError:
 | 
| -                    # can't check further if we can't infer it
 | 
| -                    break
 | 
| -
 | 
| -
 | 
| -
 | 
| -class StringConstantChecker(BaseTokenChecker):
 | 
| -    """Check string literals"""
 | 
| -    __implements__ = (ITokenChecker, IRawChecker)
 | 
| -    name = 'string_constant'
 | 
| -    msgs = {
 | 
| -        'W1401': ('Anomalous backslash in string: \'%s\'. '
 | 
| -                  'String constant might be missing an r prefix.',
 | 
| -                  'anomalous-backslash-in-string',
 | 
| -                  'Used when a backslash is in a literal string but not as an '
 | 
| -                  'escape.'),
 | 
| -        'W1402': ('Anomalous Unicode escape in byte string: \'%s\'. '
 | 
| -                  'String constant might be missing an r or u prefix.',
 | 
| -                  'anomalous-unicode-escape-in-string',
 | 
| -                  'Used when an escape like \\u is encountered in a byte '
 | 
| -                  'string where it has no effect.'),
 | 
| -        }
 | 
| -
 | 
| -    # Characters that have a special meaning after a backslash in either
 | 
| -    # Unicode or byte strings.
 | 
| -    ESCAPE_CHARACTERS = 'abfnrtvx\n\r\t\\\'\"01234567'
 | 
| -
 | 
| -    # TODO(mbp): Octal characters are quite an edge case today; people may
 | 
| -    # prefer a separate warning where they occur.  \0 should be allowed.
 | 
| -
 | 
| -    # Characters that have a special meaning after a backslash but only in
 | 
| -    # Unicode strings.
 | 
| -    UNICODE_ESCAPE_CHARACTERS = 'uUN'
 | 
| -
 | 
| -    def process_module(self, module):
 | 
| -        self._unicode_literals = 'unicode_literals' in module.future_imports
 | 
| -
 | 
| -    def process_tokens(self, tokens):
 | 
| -        for (tok_type, token, (start_row, start_col), _, _) in tokens:
 | 
| -            if tok_type == tokenize.STRING:
 | 
| -                # 'token' is the whole un-parsed token; we can look at the start
 | 
| -                # of it to see whether it's a raw or unicode string etc.
 | 
| -                self.process_string_token(token, start_row, start_col)
 | 
| -
 | 
| -    def process_string_token(self, token, start_row, start_col):
 | 
| -        for i, c in enumerate(token):
 | 
| -            if c in '\'\"':
 | 
| -                quote_char = c
 | 
| -                break
 | 
| -        prefix = token[:i].lower() #  markers like u, b, r.
 | 
| -        after_prefix = token[i:]
 | 
| -        if after_prefix[:3] == after_prefix[-3:] == 3 * quote_char:
 | 
| -            string_body = after_prefix[3:-3]
 | 
| -        else:
 | 
| -            string_body = after_prefix[1:-1]  # Chop off quotes
 | 
| -        # No special checks on raw strings at the moment.
 | 
| -        if 'r' not in prefix:
 | 
| -            self.process_non_raw_string_token(prefix, string_body,
 | 
| -                                              start_row, start_col)
 | 
| -
 | 
| -    def process_non_raw_string_token(self, prefix, string_body, start_row,
 | 
| -                                     start_col):
 | 
| -        """check for bad escapes in a non-raw string.
 | 
| -
 | 
| -        prefix: lowercase string of eg 'ur' string prefix markers.
 | 
| -        string_body: the un-parsed body of the string, not including the quote
 | 
| -        marks.
 | 
| -        start_row: integer line number in the source.
 | 
| -        start_col: integer column number in the source.
 | 
| -        """
 | 
| -        # Walk through the string; if we see a backslash then escape the next
 | 
| -        # character, and skip over it.  If we see a non-escaped character,
 | 
| -        # alert, and continue.
 | 
| -        #
 | 
| -        # Accept a backslash when it escapes a backslash, or a quote, or
 | 
| -        # end-of-line, or one of the letters that introduce a special escape
 | 
| -        # sequence <http://docs.python.org/reference/lexical_analysis.html>
 | 
| -        #
 | 
| -        # TODO(mbp): Maybe give a separate warning about the rarely-used
 | 
| -        # \a \b \v \f?
 | 
| -        #
 | 
| -        # TODO(mbp): We could give the column of the problem character, but
 | 
| -        # add_message doesn't seem to have a way to pass it through at present.
 | 
| -        i = 0
 | 
| -        while True:
 | 
| -            i = string_body.find('\\', i)
 | 
| -            if i == -1:
 | 
| -                break
 | 
| -            # There must be a next character; having a backslash at the end
 | 
| -            # of the string would be a SyntaxError.
 | 
| -            next_char = string_body[i+1]
 | 
| -            match = string_body[i:i+2]
 | 
| -            if next_char in self.UNICODE_ESCAPE_CHARACTERS:
 | 
| -                if 'u' in prefix:
 | 
| -                    pass
 | 
| -                elif (_PY3K or self._unicode_literals) and 'b' not in prefix:
 | 
| -                    pass  # unicode by default
 | 
| -                else:
 | 
| -                    self.add_message('anomalous-unicode-escape-in-string',
 | 
| -                                     line=start_row, args=(match, ))
 | 
| -            elif next_char not in self.ESCAPE_CHARACTERS:
 | 
| -                self.add_message('anomalous-backslash-in-string',
 | 
| -                                 line=start_row, args=(match, ))
 | 
| -            # Whether it was a valid escape or not, backslash followed by
 | 
| -            # another character can always be consumed whole: the second
 | 
| -            # character can never be the start of a new backslash escape.
 | 
| -            i += 2
 | 
| -
 | 
| -
 | 
| -
 | 
| -def register(linter):
 | 
| -    """required method to auto register this checker """
 | 
| -    linter.register_checker(StringFormatChecker(linter))
 | 
| -    linter.register_checker(StringMethodsChecker(linter))
 | 
| -    linter.register_checker(StringConstantChecker(linter))
 | 
| 
 |