AMiRo-OS

#!/usr/bin/env python

#

# Copyright (c) 2009 Google Inc. All rights reserved.

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions are

# met:

#

#    * Redistributions of source code must retain the above copyright

# notice, this list of conditions and the following disclaimer.

#    * Redistributions in binary form must reproduce the above

# copyright notice, this list of conditions and the following disclaimer

# in the documentation and/or other materials provided with the

# distribution.

#    * Neither the name of Google Inc. nor the names of its

# contributors may be used to endorse or promote products derived from

# this software without specific prior written permission.

#

# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""Does google-lint on c++ files.

The goal of this script is to identify places in the code that *may*

be in non-compliance with google style.  It does not attempt to fix

up these problems -- the point is to educate.  It does also not

attempt to find all problems, or to ensure that everything it does

find is legitimately a problem.

In particular, we can get very confused by /* and // inside strings!

We do a small hack, which is to ignore //'s with "'s after them on the

same line, but it is far from perfect (in either direction).

"""

import codecs

import copy

import getopt

import math  # for log

import os

import re

import sre_compile

import string

import sys

import unicodedata

_USAGE = """

Syntax: cpplint.py [--verbose=#] [--output=vs7] [--filter=-x,+y,...]

                   [--counting=total|toplevel|detailed] [--root=subdir]

                   [--linelength=digits]

        <file> [file] ...

  The style guidelines this tries to follow are those in

    http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml

  Every problem is given a confidence score from 1-5, with 5 meaning we are

  certain of the problem, and 1 meaning it could be a legitimate construct.

  This will miss some errors, and is not a substitute for a code review.

  To suppress false-positive errors of a certain category, add a

  'NOLINT(category)' comment to the line.  NOLINT or NOLINT(*)

  suppresses errors of all categories on that line.

  The files passed in will be linted; at least one file must be provided.

  Default linted extensions are .cc, .cpp, .cu, .cuh and .h.  Change the

  extensions with the --extensions flag.

  Flags:

    output=vs7

      By default, the output is formatted to ease emacs parsing.  Visual Studio

      compatible output (vs7) may also be used.  Other formats are unsupported.

    verbose=#

      Specify a number 0-5 to restrict errors to certain verbosity levels.

    filter=-x,+y,...

      Specify a comma-separated list of category-filters to apply: only

      error messages whose category names pass the filters will be printed.

      (Category names are printed with the message and look like

      "[whitespace/indent]".)  Filters are evaluated left to right.

      "-FOO" and "FOO" means "do not print categories that start with FOO".

      "+FOO" means "do print categories that start with FOO".

      Examples: --filter=-whitespace,+whitespace/braces

                --filter=whitespace,runtime/printf,+runtime/printf_format

                --filter=-,+build/include_what_you_use

      To see a list of all the categories used in cpplint, pass no arg:

         --filter=

    counting=total|toplevel|detailed

      The total number of errors found is always printed. If

      'toplevel' is provided, then the count of errors in each of

      the top-level categories like 'build' and 'whitespace' will

      also be printed. If 'detailed' is provided, then a count

      is provided for each category like 'build/class'.

    root=subdir

      The root directory used for deriving header guard CPP variable.

      By default, the header guard CPP variable is calculated as the relative

      path to the directory that contains .git, .hg, or .svn.  When this flag

      is specified, the relative path is calculated from the specified

      directory. If the specified directory does not exist, this flag is

      ignored.

      Examples:

        Assuming that src/.git exists, the header guard CPP variables for

        src/chrome/browser/ui/browser.h are:

        No flag => CHROME_BROWSER_UI_BROWSER_H_

        --root=chrome => BROWSER_UI_BROWSER_H_

        --root=chrome/browser => UI_BROWSER_H_

    linelength=digits

      This is the allowed line length for the project. The default value is

      80 characters.

      Examples:

        --linelength=120

    extensions=extension,extension,...

      The allowed file extensions that cpplint will check

      Examples:

        --extensions=hpp,cpp

    cpplint.py supports per-directory configurations specified in CPPLINT.cfg

    files. CPPLINT.cfg file can contain a number of key=value pairs.

    Currently the following options are supported:

      set noparent

      filter=+filter1,-filter2,...

      exclude_files=regex

      linelength=80

    "set noparent" option prevents cpplint from traversing directory tree

    upwards looking for more .cfg files in parent directories. This option

    is usually placed in the top-level project directory.

    The "filter" option is similar in function to --filter flag. It specifies

    message filters in addition to the |_DEFAULT_FILTERS| and those specified

    through --filter command-line flag.

    "exclude_files" allows to specify a regular expression to be matched against

    a file name. If the expression matches, the file is skipped and not run

    through liner.

    "linelength" allows to specify the allowed line length for the project.

    CPPLINT.cfg has an effect on files in the same directory and all

    sub-directories, unless overridden by a nested configuration file.

      Example file:

        filter=-build/include_order,+build/include_alpha

        exclude_files=.*\.cc

    The above example disables build/include_order warning and enables

    build/include_alpha as well as excludes all .cc from being

    processed by linter, in the current directory (where the .cfg

    file is located) and all sub-directories.

"""

# We categorize each error message we print.  Here are the categories.

# We want an explicit list so we can list them all in cpplint --filter=.

# If you add a new error message with a new category, add it to the list

# here!  cpplint_unittest.py should tell you if you forget to do this.

_ERROR_CATEGORIES = [

    'build/class',

    'build/c++11',

    'build/deprecated',

    'build/endif_comment',

    'build/explicit_make_pair',

    'build/forward_decl',

    'build/header_guard',

    'build/include',

    'build/include_alpha',

    'build/include_order',

    'build/include_what_you_use',

    'build/namespaces',

    'build/printf_format',

    'build/storage_class',

    'legal/copyright',

    'readability/alt_tokens',

    'readability/braces',

    'readability/casting',

    'readability/check',

    'readability/constructors',

    'readability/fn_size',

    'readability/function',

    'readability/inheritance',

    'readability/multiline_comment',

    'readability/multiline_string',

    'readability/namespace',

    'readability/nolint',

    'readability/nul',

    'readability/strings',

    'readability/todo',

    'readability/utf8',

    'runtime/arrays',

    'runtime/casting',

    'runtime/explicit',

    'runtime/int',

    'runtime/init',

    'runtime/invalid_increment',

    'runtime/member_string_references',

    'runtime/memset',

    'runtime/indentation_namespace',

    'runtime/operator',

    'runtime/printf',

    'runtime/printf_format',

    'runtime/references',

    'runtime/string',

    'runtime/threadsafe_fn',

    'runtime/vlog',

    'whitespace/blank_line',

    'whitespace/braces',

    'whitespace/comma',

    'whitespace/comments',

    'whitespace/empty_conditional_body',

    'whitespace/empty_loop_body',

    'whitespace/end_of_line',

    'whitespace/ending_newline',

    'whitespace/forcolon',

    'whitespace/indent',

    'whitespace/line_length',

    'whitespace/newline',

    'whitespace/operators',

    'whitespace/parens',

    'whitespace/semicolon',

    'whitespace/tab',

    'whitespace/todo',

    ]

# These error categories are no longer enforced by cpplint, but for backwards-

# compatibility they may still appear in NOLINT comments.

_LEGACY_ERROR_CATEGORIES = [

    'readability/streams',

    ]

# The default state of the category filter. This is overridden by the --filter=

# flag. By default all errors are on, so only add here categories that should be

# off by default (i.e., categories that must be enabled by the --filter= flags).

# All entries here should start with a '-' or '+', as in the --filter= flag.

_DEFAULT_FILTERS = ['-build/include_alpha']

# We used to check for high-bit characters, but after much discussion we

# decided those were OK, as long as they were in UTF-8 and didn't represent

# hard-coded international strings, which belong in a separate i18n file.

# C++ headers

_CPP_HEADERS = frozenset([

    # Legacy

    'algobase.h',

    'algo.h',

    'alloc.h',

    'builtinbuf.h',

    'bvector.h',

    'complex.h',

    'defalloc.h',

    'deque.h',

    'editbuf.h',

    'fstream.h',

    'function.h',

    'hash_map',

    'hash_map.h',

    'hash_set',

    'hash_set.h',

    'hashtable.h',

    'heap.h',

    'indstream.h',

    'iomanip.h',

    'iostream.h',

    'istream.h',

    'iterator.h',

    'list.h',

    'map.h',

    'multimap.h',

    'multiset.h',

    'ostream.h',

    'pair.h',

    'parsestream.h',

    'pfstream.h',

    'procbuf.h',

    'pthread_alloc',

    'pthread_alloc.h',

    'rope',

    'rope.h',

    'ropeimpl.h',

    'set.h',

    'slist',

    'slist.h',

    'stack.h',

    'stdiostream.h',

    'stl_alloc.h',

    'stl_relops.h',

    'streambuf.h',

    'stream.h',

    'strfile.h',

    'strstream.h',

    'tempbuf.h',

    'tree.h',

    'type_traits.h',

    'vector.h',

    # 17.6.1.2 C++ library headers

    'algorithm',

    'array',

    'atomic',

    'bitset',

    'chrono',

    'codecvt',

    'complex',

    'condition_variable',

    'deque',

    'exception',

    'forward_list',

    'fstream',

    'functional',

    'future',

    'initializer_list',

    'iomanip',

    'ios',

    'iosfwd',

    'iostream',

    'istream',

    'iterator',

    'limits',

    'list',

    'locale',

    'map',

    'memory',

    'mutex',

    'new',

    'numeric',

    'ostream',

    'queue',

    'random',

    'ratio',

    'regex',

    'set',

    'sstream',

    'stack',

    'stdexcept',

    'streambuf',

    'string',

    'strstream',

    'system_error',

    'thread',

    'tuple',

    'typeindex',

    'typeinfo',

    'type_traits',

    'unordered_map',

    'unordered_set',

    'utility',

    'valarray',

    'vector',

    # 17.6.1.2 C++ headers for C library facilities

    'cassert',

    'ccomplex',

    'cctype',

    'cerrno',

    'cfenv',

    'cfloat',

    'cinttypes',

    'ciso646',

    'climits',

    'clocale',

    'cmath',

    'csetjmp',

    'csignal',

    'cstdalign',

    'cstdarg',

    'cstdbool',

    'cstddef',

    'cstdint',

    'cstdio',

    'cstdlib',

    'cstring',

    'ctgmath',

    'ctime',

    'cuchar',

    'cwchar',

    'cwctype',

    ])

# These headers are excluded from [build/include] and [build/include_order]

# checks:

# - Anything not following google file name conventions (containing an

#   uppercase character, such as Python.h or nsStringAPI.h, for example).

# - Lua headers.

_THIRD_PARTY_HEADERS_PATTERN = re.compile(

    r'^(?:[^/]*[A-Z][^/]*\.h|lua\.h|lauxlib\.h|lualib\.h)$')

# Assertion macros.  These are defined in base/logging.h and

# testing/base/gunit.h.  Note that the _M versions need to come first

# for substring matching to work.

_CHECK_MACROS = [

    'DCHECK', 'CHECK',

    'EXPECT_TRUE_M', 'EXPECT_TRUE',

    'ASSERT_TRUE_M', 'ASSERT_TRUE',

    'EXPECT_FALSE_M', 'EXPECT_FALSE',

    'ASSERT_FALSE_M', 'ASSERT_FALSE',

    ]

# Replacement macros for CHECK/DCHECK/EXPECT_TRUE/EXPECT_FALSE

_CHECK_REPLACEMENT = dict([(m, {}) for m in _CHECK_MACROS])

for op, replacement in [('==', 'EQ'), ('!=', 'NE'),

                        ('>=', 'GE'), ('>', 'GT'),

                        ('<=', 'LE'), ('<', 'LT')]:

  _CHECK_REPLACEMENT['DCHECK'][op] = 'DCHECK_%s' % replacement

  _CHECK_REPLACEMENT['CHECK'][op] = 'CHECK_%s' % replacement

  _CHECK_REPLACEMENT['EXPECT_TRUE'][op] = 'EXPECT_%s' % replacement

  _CHECK_REPLACEMENT['ASSERT_TRUE'][op] = 'ASSERT_%s' % replacement

  _CHECK_REPLACEMENT['EXPECT_TRUE_M'][op] = 'EXPECT_%s_M' % replacement

  _CHECK_REPLACEMENT['ASSERT_TRUE_M'][op] = 'ASSERT_%s_M' % replacement

for op, inv_replacement in [('==', 'NE'), ('!=', 'EQ'),

                            ('>=', 'LT'), ('>', 'LE'),

                            ('<=', 'GT'), ('<', 'GE')]:

  _CHECK_REPLACEMENT['EXPECT_FALSE'][op] = 'EXPECT_%s' % inv_replacement

  _CHECK_REPLACEMENT['ASSERT_FALSE'][op] = 'ASSERT_%s' % inv_replacement

  _CHECK_REPLACEMENT['EXPECT_FALSE_M'][op] = 'EXPECT_%s_M' % inv_replacement

  _CHECK_REPLACEMENT['ASSERT_FALSE_M'][op] = 'ASSERT_%s_M' % inv_replacement

# Alternative tokens and their replacements.  For full list, see section 2.5

# Alternative tokens [lex.digraph] in the C++ standard.

#

# Digraphs (such as '%:') are not included here since it's a mess to

# match those on a word boundary.

_ALT_TOKEN_REPLACEMENT = {

    'and': '&&',

    'bitor': '|',

    'or': '||',

    'xor': '^',

    'compl': '~',

    'bitand': '&',

    'and_eq': '&=',

    'or_eq': '|=',

    'xor_eq': '^=',

    'not': '!',

    'not_eq': '!='

    }

# Compile regular expression that matches all the above keywords.  The "[ =()]"

# bit is meant to avoid matching these keywords outside of boolean expressions.

#

# False positives include C-style multi-line comments and multi-line strings

# but those have always been troublesome for cpplint.

_ALT_TOKEN_REPLACEMENT_PATTERN = re.compile(

    r'[ =()](' + ('|'.join(_ALT_TOKEN_REPLACEMENT.keys())) + r')(?=[ (]|$)')

# These constants define types of headers for use with

# _IncludeState.CheckNextIncludeOrder().

_C_SYS_HEADER = 1

_CPP_SYS_HEADER = 2

_LIKELY_MY_HEADER = 3

_POSSIBLE_MY_HEADER = 4

_OTHER_HEADER = 5

# These constants define the current inline assembly state

_NO_ASM = 0       # Outside of inline assembly block

_INSIDE_ASM = 1   # Inside inline assembly block

_END_ASM = 2      # Last line of inline assembly block

_BLOCK_ASM = 3    # The whole block is an inline assembly block

# Match start of assembly blocks

_MATCH_ASM = re.compile(r'^\s*(?:asm|_asm|__asm|__asm__)'

                        r'(?:\s+(volatile|__volatile__))?'

                        r'\s*[{(]')

_regexp_compile_cache = {}

# {str, set(int)}: a map from error categories to sets of linenumbers

# on which those errors are expected and should be suppressed.

_error_suppressions = {}

# The root directory used for deriving header guard CPP variable.

# This is set by --root flag.

_root = None

# The allowed line length of files.

# This is set by --linelength flag.

_line_length = 80

# The allowed extensions for file names

# This is set by --extensions flag.

_valid_extensions = set(['cc', 'h', 'cpp', 'cu', 'cuh'])

def ParseNolintSuppressions(filename, raw_line, linenum, error):

  """Updates the global list of error-suppressions.

  Parses any NOLINT comments on the current line, updating the global

  error_suppressions store.  Reports an error if the NOLINT comment

  was malformed.

  Args:

    filename: str, the name of the input file.

    raw_line: str, the line of input text, with comments.

    linenum: int, the number of the current line.

    error: function, an error handler.

  """

  matched = Search(r'\bNOLINT(NEXTLINE)?\b(\([^)]+\))?', raw_line)

  if matched:

    if matched.group(1):

      suppressed_line = linenum + 1

    else:

      suppressed_line = linenum

    category = matched.group(2)

    if category in (None, '(*)'):  # => "suppress all"

      _error_suppressions.setdefault(None, set()).add(suppressed_line)

    else:

      if category.startswith('(') and category.endswith(')'):

        category = category[1:-1]

        if category in _ERROR_CATEGORIES:

          _error_suppressions.setdefault(category, set()).add(suppressed_line)

        elif category not in _LEGACY_ERROR_CATEGORIES:

          error(filename, linenum, 'readability/nolint', 5,

                'Unknown NOLINT error category: %s' % category)

def ResetNolintSuppressions():

  """Resets the set of NOLINT suppressions to empty."""

  _error_suppressions.clear()

def IsErrorSuppressedByNolint(category, linenum):

  """Returns true if the specified error category is suppressed on this line.

  Consults the global error_suppressions map populated by

  ParseNolintSuppressions/ResetNolintSuppressions.

  Args:

    category: str, the category of the error.

    linenum: int, the current line number.

  Returns:

    bool, True iff the error should be suppressed due to a NOLINT comment.

  """

  return (linenum in _error_suppressions.get(category, set()) or

          linenum in _error_suppressions.get(None, set()))

def Match(pattern, s):

  """Matches the string with the pattern, caching the compiled regexp."""

  # The regexp compilation caching is inlined in both Match and Search for

  # performance reasons; factoring it out into a separate function turns out

  # to be noticeably expensive.

  if pattern not in _regexp_compile_cache:

    _regexp_compile_cache[pattern] = sre_compile.compile(pattern)

  return _regexp_compile_cache[pattern].match(s)

def ReplaceAll(pattern, rep, s):

  """Replaces instances of pattern in a string with a replacement.

  The compiled regex is kept in a cache shared by Match and Search.

  Args:

    pattern: regex pattern

    rep: replacement text

    s: search string

  Returns:

    string with replacements made (or original string if no replacements)

  """

  if pattern not in _regexp_compile_cache:

    _regexp_compile_cache[pattern] = sre_compile.compile(pattern)

  return _regexp_compile_cache[pattern].sub(rep, s)

def Search(pattern, s):

  """Searches the string for the pattern, caching the compiled regexp."""

  if pattern not in _regexp_compile_cache:

    _regexp_compile_cache[pattern] = sre_compile.compile(pattern)

  return _regexp_compile_cache[pattern].search(s)

class _IncludeState(object):

  """Tracks line numbers for includes, and the order in which includes appear.

  include_list contains list of lists of (header, line number) pairs.

  It's a lists of lists rather than just one flat list to make it

  easier to update across preprocessor boundaries.

  Call CheckNextIncludeOrder() once for each header in the file, passing

  in the type constants defined above. Calls in an illegal order will

  raise an _IncludeError with an appropriate error message.

  """

  # self._section will move monotonically through this set. If it ever

  # needs to move backwards, CheckNextIncludeOrder will raise an error.

  _INITIAL_SECTION = 0

  _MY_H_SECTION = 1

  _C_SECTION = 2

  _CPP_SECTION = 3

  _OTHER_H_SECTION = 4

  _TYPE_NAMES = {

      _C_SYS_HEADER: 'C system header',

      _CPP_SYS_HEADER: 'C++ system header',

      _LIKELY_MY_HEADER: 'header this file implements',

      _POSSIBLE_MY_HEADER: 'header this file may implement',

      _OTHER_HEADER: 'other header',

      }

  _SECTION_NAMES = {

      _INITIAL_SECTION: "... nothing. (This can't be an error.)",

      _MY_H_SECTION: 'a header this file implements',

      _C_SECTION: 'C system header',

      _CPP_SECTION: 'C++ system header',

      _OTHER_H_SECTION: 'other header',

      }

  def __init__(self):

    self.include_list = [[]]

    self.ResetSection('')

  def FindHeader(self, header):

    """Check if a header has already been included.

    Args:

      header: header to check.

    Returns:

      Line number of previous occurrence, or -1 if the header has not

      been seen before.

    """

    for section_list in self.include_list:

      for f in section_list:

        if f[0] == header:

          return f[1]

    return -1

  def ResetSection(self, directive):

    """Reset section checking for preprocessor directive.

    Args:

      directive: preprocessor directive (e.g. "if", "else").

    """

    # The name of the current section.

    self._section = self._INITIAL_SECTION

    # The path of last found header.

    self._last_header = ''

    # Update list of includes.  Note that we never pop from the

    # include list.

    if directive in ('if', 'ifdef', 'ifndef'):

      self.include_list.append([])

    elif directive in ('else', 'elif'):

      self.include_list[-1] = []

  def SetLastHeader(self, header_path):

    self._last_header = header_path

  def CanonicalizeAlphabeticalOrder(self, header_path):

    """Returns a path canonicalized for alphabetical comparison.

    - replaces "-" with "_" so they both cmp the same.

    - removes '-inl' since we don't require them to be after the main header.

    - lowercase everything, just in case.

    Args:

      header_path: Path to be canonicalized.

    Returns:

      Canonicalized path.

    """

    return header_path.replace('-inl.h', '.h').replace('-', '_').lower()

  def IsInAlphabeticalOrder(self, clean_lines, linenum, header_path):

    """Check if a header is in alphabetical order with the previous header.

    Args:

      clean_lines: A CleansedLines instance containing the file.

      linenum: The number of the line to check.

      header_path: Canonicalized header to be checked.

    Returns:

      Returns true if the header is in alphabetical order.

    """

    # If previous section is different from current section, _last_header will

    # be reset to empty string, so it's always less than current header.

    #

    # If previous line was a blank line, assume that the headers are

    # intentionally sorted the way they are.

    if (self._last_header > header_path and

        Match(r'^\s*#\s*include\b', clean_lines.elided[linenum - 1])):

      return False

    return True

  def CheckNextIncludeOrder(self, header_type):

    """Returns a non-empty error message if the next header is out of order.

    This function also updates the internal state to be ready to check

    the next include.

    Args:

      header_type: One of the _XXX_HEADER constants defined above.

    Returns:

      The empty string if the header is in the right order, or an

      error message describing what's wrong.

    """

    error_message = ('Found %s after %s' %

                     (self._TYPE_NAMES[header_type],

                      self._SECTION_NAMES[self._section]))

    last_section = self._section

    if header_type == _C_SYS_HEADER:

      if self._section <= self._C_SECTION:

        self._section = self._C_SECTION

      else:

        self._last_header = ''

        return error_message

    elif header_type == _CPP_SYS_HEADER:

      if self._section <= self._CPP_SECTION:

        self._section = self._CPP_SECTION

      else:

        self._last_header = ''

        return error_message

    elif header_type == _LIKELY_MY_HEADER:

      if self._section <= self._MY_H_SECTION:

        self._section = self._MY_H_SECTION

      else:

        self._section = self._OTHER_H_SECTION

    elif header_type == _POSSIBLE_MY_HEADER:

      if self._section <= self._MY_H_SECTION:

        self._section = self._MY_H_SECTION

      else:

        # This will always be the fallback because we're not sure

        # enough that the header is associated with this file.

        self._section = self._OTHER_H_SECTION

    else:

      assert header_type == _OTHER_HEADER

      self._section = self._OTHER_H_SECTION

    if last_section != self._section:

      self._last_header = ''

    return ''

class _CppLintState(object):

  """Maintains module-wide state.."""

  def __init__(self):

    self.verbose_level = 1  # global setting.

    self.error_count = 0    # global count of reported errors

    # filters to apply when emitting error messages

    self.filters = _DEFAULT_FILTERS[:]

    # backup of filter list. Used to restore the state after each file.

    self._filters_backup = self.filters[:]

    self.counting = 'total'  # In what way are we counting errors?

    self.errors_by_category = {}  # string to int dict storing error counts

    # output format:

    # "emacs" - format that emacs can parse (default)

    # "vs7" - format that Microsoft Visual Studio 7 can parse

    self.output_format = 'emacs'

  def SetOutputFormat(self, output_format):

    """Sets the output format for errors."""