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#!/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
import sysconfig
try:
xrange # Python 2
except NameError:
xrange = range # Python 3
_USAGE = """
Syntax: cpplint.py [--verbose=#] [--output=vs7] [--filter=-x,+y,...]
[--counting=total|toplevel|detailed] [--root=subdir]
[--linelength=digits] [--headers=x,y,...]
[--quiet]
<file> [file] ...
The style guidelines this tries to follow are those in
https://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.
quiet
Don't print anything if no errors are found.
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 top/src/.git exists (and cwd=top/src), the header guard
CPP variables for top/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_
--root=.. => SRC_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
headers=x,y,...
The header extensions that cpplint will treat as .h in checks. Values are
automatically added to --extensions list.
Examples:
--headers=hpp,hxx
--headers=hpp
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
root=subdir
headers=x,y,...
"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.
The "root" option is similar in function to the --root flag (see example
above). Paths are relative to the directory of the CPPLINT.cfg.
The "headers" option is similar in function to the --headers flag
(see example above).
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/c++14',
'build/c++tr1',
'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/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_if_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',
'readability/function',
]
# 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']
# The default list of categories suppressed for C (not C++) files.
_DEFAULT_C_SUPPRESSED_CATEGORIES = [
'readability/casting',
]
# The default list of categories suppressed for Linux Kernel files.
_DEFAULT_KERNEL_SUPPRESSED_CATEGORIES = [
'whitespace/tab',
]
# 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',
'scoped_allocator',
'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',
])
# Type names
_TYPES = re.compile(
r'^(?:'
# [dcl.type.simple]
r'(char(16_t|32_t)?)|wchar_t|'
r'bool|short|int|long|signed|unsigned|float|double|'
# [support.types]
r'(ptrdiff_t|size_t|max_align_t|nullptr_t)|'
# [cstdint.syn]
r'(u?int(_fast|_least)?(8|16|32|64)_t)|'
r'(u?int(max|ptr)_t)|'
r')$')
# These headers are excluded from [build/include] and [build/include_order]
# checks:
# - Anything not following google file name conventions (containing an
# uppercase character, such as Python.h or nsStringAPI.h, for example).
# - Lua headers.
_THIRD_PARTY_HEADERS_PATTERN = re.compile(
r'^(?:[^/]*[A-Z][^/]*\.h|lua\.h|lauxlib\.h|lualib\.h)$')
# Pattern for matching FileInfo.BaseName() against test file name
_TEST_FILE_SUFFIX = r'(_test|_unittest|_regtest)$'
# Pattern that matches only complete whitespace, possibly across multiple lines.
_EMPTY_CONDITIONAL_BODY_PATTERN = re.compile(r'^\s*$', re.DOTALL)
# Assertion macros. These are defined in base/logging.h and
# testing/base/public/gunit.h.
_CHECK_MACROS = [
'DCHECK', 'CHECK',
'EXPECT_TRUE', 'ASSERT_TRUE',
'EXPECT_FALSE', '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
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
# 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')(?=[ (]|$)')
# These constants define types of headers for use with
# _IncludeState.CheckNextIncludeOrder().
_C_SYS_HEADER = 1
_CPP_SYS_HEADER = 2
_LIKELY_MY_HEADER = 3
_POSSIBLE_MY_HEADER = 4
_OTHER_HEADER = 5
# These constants define the current inline assembly state
_NO_ASM = 0 # Outside of inline assembly block
_INSIDE_ASM = 1 # Inside inline assembly block
_END_ASM = 2 # Last line of inline assembly block
_BLOCK_ASM = 3 # The whole block is an inline assembly block
# Match start of assembly blocks
_MATCH_ASM = re.compile(r'^\s*(?:asm|_asm|__asm|__asm__)'
r'(?:\s+(volatile|__volatile__))?'
r'\s*[{(]')
# Match strings that indicate we're working on a C (not C++) file.
_SEARCH_C_FILE = re.compile(r'\b(?:LINT_C_FILE|'
r'vim?:\s*.*(\s*|:)filetype=c(\s*|:|$))')
# Match string that indicates we're working on a Linux Kernel file.
_SEARCH_KERNEL_FILE = re.compile(r'\b(?:LINT_KERNEL_FILE)')
_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
_root_debug = False
# 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'])
# Treat all headers starting with 'h' equally: .h, .hpp, .hxx etc.
# This is set by --headers flag.
_hpp_headers = set(['h'])
# {str, bool}: a map from error categories to booleans which indicate if the
# category should be suppressed for every line.
_global_error_suppressions = {}
def ProcessHppHeadersOption(val):
global _hpp_headers
try:
_hpp_headers = set(val.split(','))
# Automatically append to extensions list so it does not have to be set 2 times
_valid_extensions.update(_hpp_headers)
except ValueError:
PrintUsage('Header extensions must be comma separated list.')
def IsHeaderExtension(file_extension):
return file_extension in _hpp_headers
def ParseNolintSuppressions(filename, raw_line, linenum, error):
"""Updates the global list of line 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 ProcessGlobalSuppresions(lines):
"""Updates the list of global error suppressions.
Parses any lint directives in the file that have global effect.
Args:
lines: An array of strings, each representing a line of the file, with the
last element being empty if the file is terminated with a newline.
"""
for line in lines:
if _SEARCH_C_FILE.search(line):
for category in _DEFAULT_C_SUPPRESSED_CATEGORIES:
_global_error_suppressions[category] = True
if _SEARCH_KERNEL_FILE.search(line):
for category in _DEFAULT_KERNEL_SUPPRESSED_CATEGORIES:
_global_error_suppressions[category] = True
def ResetNolintSuppressions():
"""Resets the set of NOLINT suppressions to empty."""
_error_suppressions.clear()
_global_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/ProcessGlobalSuppresions/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 or
global suppression.
"""
return (_global_error_suppressions.get(category, False) or
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)
def _IsSourceExtension(s):
"""File extension (excluding dot) matches a source file extension."""
return s in ('c', 'cc', 'cpp', 'cxx')
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
self.quiet = False # Suppress non-error messagess?
# 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."""
self.output_format = output_format
def SetQuiet(self, quiet):
"""Sets the module's quiet settings, and returns the previous setting."""
last_quiet = self.quiet
self.quiet = quiet
return last_quiet
def SetVerboseLevel(self, level):
"""Sets the module's verbosity, and returns the previous setting."""
last_verbose_level = self.verbose_level
self.verbose_level = level
return last_verbose_level
def SetCountingStyle(self, counting_style):
"""Sets the module's counting options."""
self.counting = counting_style
def SetFilters(self, filters):
"""Sets the error-message filters.
These filters are applied when deciding whether to emit a given
error message.
Args:
filters: A string of comma-separated filters (eg "+whitespace/indent").
Each filter should start with + or -; else we die.
Raises:
ValueError: The comma-separated filters did not all start with '+' or '-'.
E.g. "-,+whitespace,-whitespace/indent,whitespace/badfilter"
"""
# Default filters always have less priority than the flag ones.
self.filters = _DEFAULT_FILTERS[:]
self.AddFilters(filters)
def AddFilters(self, filters):
""" Adds more filters to the existing list of error-message filters. """
for filt in filters.split(','):
clean_filt = filt.strip()
if clean_filt:
self.filters.append(clean_filt)
for filt in self.filters:
if not (filt.startswith('+') or filt.startswith('-')):
raise ValueError('Every filter in --filters must start with + or -'
' (%s does not)' % filt)
def BackupFilters(self):
""" Saves the current filter list to backup storage."""
self._filters_backup = self.filters[:]
def RestoreFilters(self):
""" Restores filters previously backed up."""
self.filters = self._filters_backup[:]
def ResetErrorCounts(self):
"""Sets the module's error statistic back to zero."""
self.error_count = 0
self.errors_by_category = {}
def IncrementErrorCount(self, category):
"""Bumps the module's error statistic."""
self.error_count += 1
if self.counting in ('toplevel', 'detailed'):
if self.counting != 'detailed':
category = category.split('/')[0]
if category not in self.errors_by_category:
self.errors_by_category[category] = 0
self.errors_by_category[category] += 1
def PrintErrorCounts(self):
"""Print a summary of errors by category, and the total."""
for category, count in self.errors_by_category.iteritems():
sys.stderr.write('Category \'%s\' errors found: %d\n' %
(category, count))
sys.stdout.write('Total errors found: %d\n' % self.error_count)
_cpplint_state = _CppLintState()
def _OutputFormat():
"""Gets the module's output format."""
return _cpplint_state.output_format
def _SetOutputFormat(output_format):
"""Sets the module's output format."""
_cpplint_state.SetOutputFormat(output_format)
def _Quiet():
"""Return's the module's quiet setting."""
return _cpplint_state.quiet
def _SetQuiet(quiet):
"""Set the module's quiet status, and return previous setting."""
return _cpplint_state.SetQuiet(quiet)
def _VerboseLevel():
"""Returns the module's verbosity setting."""
return _cpplint_state.verbose_level
def _SetVerboseLevel(level):
"""Sets the module's verbosity, and returns the previous setting."""
return _cpplint_state.SetVerboseLevel(level)
def _SetCountingStyle(level):
"""Sets the module's counting options."""
_cpplint_state.SetCountingStyle(level)
def _Filters():
"""Returns the module's list of output filters, as a list."""
return _cpplint_state.filters
def _SetFilters(filters):
"""Sets the module's error-message filters.
These filters are applied when deciding whether to emit a given
error message.
Args:
filters: A string of comma-separated filters (eg "whitespace/indent").
Each filter should start with + or -; else we die.
"""
_cpplint_state.SetFilters(filters)
def _AddFilters(filters):
"""Adds more filter overrides.
Unlike _SetFilters, this function does not reset the current list of filters
available.
Args:
filters: A string of comma-separated filters (eg "whitespace/indent").
Each filter should start with + or -; else we die.
"""
_cpplint_state.AddFilters(filters)
def _BackupFilters():
""" Saves the current filter list to backup storage."""
_cpplint_state.BackupFilters()
def _RestoreFilters():
""" Restores filters previously backed up."""
_cpplint_state.RestoreFilters()
class _FunctionState(object):
"""Tracks current function name and the number of lines in its body."""
_NORMAL_TRIGGER = 250 # for --v=0, 500 for --v=1, etc.
_TEST_TRIGGER = 400 # about 50% more than _NORMAL_TRIGGER.
def __init__(self):
self.in_a_function = False
self.lines_in_function = 0
self.current_function = ''
def Begin(self, function_name):
"""Start analyzing function body.
Args:
function_name: The name of the function being tracked.
"""
self.in_a_function = True
self.lines_in_function = 0
self.current_function = function_name
def Count(self):
"""Count line in current function body."""
if self.in_a_function:
self.lines_in_function += 1
def Check(self, error, filename, linenum):
"""Report if too many lines in function body.
Args:
error: The function to call with any errors found.
filename: The name of the current file.
linenum: The number of the line to check.
"""
if not self.in_a_function:
return
if Match(r'T(EST|est)', self.current_function):
base_trigger = self._TEST_TRIGGER
else:
base_trigger = self._NORMAL_TRIGGER
trigger = base_trigger * 2**_VerboseLevel()
if self.lines_in_function > trigger:
error_level = int(math.log(self.lines_in_function / base_trigger, 2))
# 50 => 0, 100 => 1, 200 => 2, 400 => 3, 800 => 4, 1600 => 5, ...
if error_level > 5:
error_level = 5
error(filename, linenum, 'readability/fn_size', error_level,
'Small and focused functions are preferred:'
' %s has %d non-comment lines'
' (error triggered by exceeding %d lines).' % (
self.current_function, self.lines_in_function, trigger))
def End(self):
"""Stop analyzing function body."""
self.in_a_function = False
class _IncludeError(Exception):
"""Indicates a problem with the include order in a file."""
pass
class FileInfo(object):
"""Provides utility functions for filenames.
FileInfo provides easy access to the components of a file's path
relative to the project root.
"""
def __init__(self, filename):
self._filename = filename
def FullName(self):
"""Make Windows paths like Unix."""
return os.path.abspath(self._filename).replace('\\', '/')
def RepositoryName(self):
"""FullName after removing the local path to the repository.
If we have a real absolute path name here we can try to do something smart:
detecting the root of the checkout and truncating /path/to/checkout from
the name so that we get header guards that don't include things like
"C:\Documents and Settings\..." or "/home/username/..." in them and thus
people on different computers who have checked the source out to different
locations won't see bogus errors.
"""
fullname = self.FullName()
if os.path.exists(fullname):
project_dir = os.path.dirname(fullname)
if os.path.exists(os.path.join(project_dir, ".svn")):
# If there's a .svn file in the current directory, we recursively look
# up the directory tree for the top of the SVN checkout
root_dir = project_dir
one_up_dir = os.path.dirname(root_dir)
while os.path.exists(os.path.join(one_up_dir, ".svn")):
root_dir = os.path.dirname(root_dir)
one_up_dir = os.path.dirname(one_up_dir)
prefix = os.path.commonprefix([root_dir, project_dir])
return fullname[len(prefix) + 1:]
# Not SVN <= 1.6? Try to find a git, hg, or svn top level directory by
# searching up from the current path.
root_dir = current_dir = os.path.dirname(fullname)
while current_dir != os.path.dirname(current_dir):
if (os.path.exists(os.path.join(current_dir, ".git")) or
os.path.exists(os.path.join(current_dir, ".hg")) or
os.path.exists(os.path.join(current_dir, ".svn"))):
root_dir = current_dir
current_dir = os.path.dirname(current_dir)
if (os.path.exists(os.path.join(root_dir, ".git")) or
os.path.exists(os.path.join(root_dir, ".hg")) or
os.path.exists(os.path.join(root_dir, ".svn"))):
prefix = os.path.commonprefix([root_dir, project_dir])
return fullname[len(prefix) + 1:]
# Don't know what to do; header guard warnings may be wrong...
return fullname
def Split(self):
"""Splits the file into the directory, basename, and extension.
For 'chrome/browser/browser.cc', Split() would
return ('chrome/browser', 'browser', '.cc')
Returns:
A tuple of (directory, basename, extension).
"""
googlename = self.RepositoryName()
project, rest = os.path.split(googlename)
return (project,) + os.path.splitext(rest)
def BaseName(self):
"""File base name - text after the final slash, before the final period."""
return self.Split()[1]
def Extension(self):
"""File extension - text following the final period."""
return self.Split()[2]
def NoExtension(self):
"""File has no source file extension."""
return '/'.join(self.Split()[0:2])
def IsSource(self):
"""File has a source file extension."""
return _IsSourceExtension(self.Extension()[1:])
def _ShouldPrintError(category, confidence, linenum):
"""If confidence >= verbose, category passes filter and is not suppressed."""
# There are three ways we might decide not to print an error message:
# a "NOLINT(category)" comment appears in the source,
# the verbosity level isn't high enough, or the filters filter it out.
if IsErrorSuppressedByNolint(category, linenum):
return False
if confidence < _cpplint_state.verbose_level:
return False
is_filtered = False
for one_filter in _Filters():
if one_filter.startswith('-'):
if category.startswith(one_filter[1:]):
is_filtered = True
elif one_filter.startswith('+'):
if category.startswith(one_filter[1:]):
is_filtered = False
else:
assert False # should have been checked for in SetFilter.
if is_filtered:
return False
return True
def Error(filename, linenum, category, confidence, message):
"""Logs the fact we've found a lint error.
We log where the error was found, and also our confidence in the error,
that is, how certain we are this is a legitimate style regression, and
not a misidentification or a use that's sometimes justified.
False positives can be suppressed by the use of
"cpplint(category)" comments on the offending line. These are
parsed into _error_suppressions.
Args:
filename: The name of the file containing the error.
linenum: The number of the line containing the error.
category: A string used to describe the "category" this bug
falls under: "whitespace", say, or "runtime". Categories
may have a hierarchy separated by slashes: "whitespace/indent".
confidence: A number from 1-5 representing a confidence score for
the error, with 5 meaning that we are certain of the problem,
and 1 meaning that it could be a legitimate construct.
message: The error message.
"""
if _ShouldPrintError(category, confidence, linenum):
_cpplint_state.IncrementErrorCount(category)
if _cpplint_state.output_format == 'vs7':
sys.stderr.write('%s(%s): error cpplint: [%s] %s [%d]\n' % (
filename, linenum, category, message, confidence))
elif _cpplint_state.output_format == 'eclipse':
sys.stderr.write('%s:%s: warning: %s [%s] [%d]\n' % (
filename, linenum, message, category, confidence))
else:
sys.stderr.write('%s:%s: %s [%s] [%d]\n' % (
filename, linenum, message, category, confidence))
# Matches standard C++ escape sequences per 2.13.2.3 of the C++ standard.
_RE_PATTERN_CLEANSE_LINE_ESCAPES = re.compile(
r'\\([abfnrtv?"\\\']|\d+|x[0-9a-fA-F]+)')
# Match a single C style comment on the same line.
_RE_PATTERN_C_COMMENTS = r'/\*(?:[^*]|\*(?!/))*\*/'
# Matches multi-line C style comments.
# This RE is a little bit more complicated than one might expect, because we
# have to take care of space removals tools so we can handle comments inside
# statements better.
# The current rule is: We only clear spaces from both sides when we're at the
# end of the line. Otherwise, we try to remove spaces from the right side,
# if this doesn't work we try on left side but only if there's a non-character
# on the right.
_RE_PATTERN_CLEANSE_LINE_C_COMMENTS = re.compile(
r'(\s*' + _RE_PATTERN_C_COMMENTS + r'\s*$|' +
_RE_PATTERN_C_COMMENTS + r'\s+|' +
r'\s+' + _RE_PATTERN_C_COMMENTS + r'(?=\W)|' +
_RE_PATTERN_C_COMMENTS + r')')
def IsCppString(line):
"""Does line terminate so, that the next symbol is in string constant.
This function does not consider single-line nor multi-line comments.
Args:
line: is a partial line of code starting from the 0..n.
Returns:
True, if next character appended to 'line' is inside a
string constant.
"""
line = line.replace(r'\\', 'XX') # after this, \\" does not match to \"
return ((line.count('"') - line.count(r'\"') - line.count("'\"'")) & 1) == 1
def CleanseRawStrings(raw_lines):
"""Removes C++11 raw strings from lines.
Before:
static const char kData[] = R"(
multi-line string
)";
After:
static const char kData[] = ""
(replaced by blank line)
"";
Args:
raw_lines: list of raw lines.
Returns:
list of lines with C++11 raw strings replaced by empty strings.
"""
delimiter = None
lines_without_raw_strings = []
for line in raw_lines:
if delimiter:
# Inside a raw string, look for the end
end = line.find(delimiter)
if end >= 0:
# Found the end of the string, match leading space for this
# line and resume copying the original lines, and also insert
# a "" on the last line.
leading_space = Match(r'^(\s*)\S', line)
line = leading_space.group(1) + '""' + line[end + len(delimiter):]
delimiter = None
else:
# Haven't found the end yet, append a blank line.
line = '""'
# Look for beginning of a raw string, and replace them with
# empty strings. This is done in a loop to handle multiple raw
# strings on the same line.
while delimiter is None:
# Look for beginning of a raw string.
# See 2.14.15 [lex.string] for syntax.
#
# Once we have matched a raw string, we check the prefix of the
# line to make sure that the line is not part of a single line
# comment. It's done this way because we remove raw strings
# before removing comments as opposed to removing comments
# before removing raw strings. This is because there are some
# cpplint checks that requires the comments to be preserved, but
# we don't want to check comments that are inside raw strings.
matched = Match(r'^(.*?)\b(?:R|u8R|uR|UR|LR)"([^\s\\()]*)\((.*)$', line)
if (matched and
not Match(r'^([^\'"]|\'(\\.|[^\'])*\'|"(\\.|[^"])*")*//',
matched.group(1))):
delimiter = ')' + matched.group(2) + '"'
end = matched.group(3).find(delimiter)
if end >= 0:
# Raw string ended on same line
line = (matched.group(1) + '""' +
matched.group(3)[end + len(delimiter):])
delimiter = None
else:
# Start of a multi-line raw string
line = matched.group(1) + '""'
else:
break
lines_without_raw_strings.append(line)
# TODO(unknown): if delimiter is not None here, we might want to
# emit a warning for unterminated string.
return lines_without_raw_strings
def FindNextMultiLineCommentStart(lines, lineix):
"""Find the beginning marker for a multiline comment."""
while lineix < len(lines):
if lines[lineix].strip().startswith('/*'):
# Only return this marker if the comment goes beyond this line
if lines[lineix].strip().find('*/', 2) < 0:
return lineix
lineix += 1
return len(lines)
def FindNextMultiLineCommentEnd(lines, lineix):
"""We are inside a comment, find the end marker."""
while lineix < len(lines):
if lines[lineix].strip().endswith('*/'):
return lineix
lineix += 1
return len(lines)
def RemoveMultiLineCommentsFromRange(lines, begin, end):
"""Clears a range of lines for multi-line comments."""
# Having // <empty> comments makes the lines non-empty, so we will not get
# unnecessary blank line warnings later in the code.
for i in range(begin, end):
lines[i] = '/**/'
def RemoveMultiLineComments(filename, lines, error):
"""Removes multiline (c-style) comments from lines."""
lineix = 0
while lineix < len(lines):
lineix_begin = FindNextMultiLineCommentStart(lines, lineix)
if lineix_begin >= len(lines):
return
lineix_end = FindNextMultiLineCommentEnd(lines, lineix_begin)
if lineix_end >= len(lines):
error(filename, lineix_begin + 1, 'readability/multiline_comment', 5,
'Could not find end of multi-line comment')
return
RemoveMultiLineCommentsFromRange(lines, lineix_begin, lineix_end + 1)
lineix = lineix_end + 1
def CleanseComments(line):
"""Removes //-comments and single-line C-style /* */ comments.
Args:
line: A line of C++ source.
Returns:
The line with single-line comments removed.
"""
commentpos = line.find('//')
if commentpos != -1 and not IsCppString(line[:commentpos]):
line = line[:commentpos].rstrip()
# get rid of /* ... */
return _RE_PATTERN_CLEANSE_LINE_C_COMMENTS.sub('', line)
class CleansedLines(object):
"""Holds 4 copies of all lines with different preprocessing applied to them.
1) elided member contains lines without strings and comments.
2) lines member contains lines without comments.
3) raw_lines member contains all the lines without processing.
4) lines_without_raw_strings member is same as raw_lines, but with C++11 raw
strings removed.
All these members are of <type 'list'>, and of the same length.
"""
def __init__(self, lines):
self.elided = []
self.lines = []
self.raw_lines = lines
self.num_lines = len(lines)
self.lines_without_raw_strings = CleanseRawStrings(lines)
for linenum in range(len(self.lines_without_raw_strings)):
self.lines.append(CleanseComments(
self.lines_without_raw_strings[linenum]))
elided = self._CollapseStrings(self.lines_without_raw_strings[linenum])
self.elided.append(CleanseComments(elided))
def NumLines(self):
"""Returns the number of lines represented."""
return self.num_lines
@staticmethod
def _CollapseStrings(elided):
"""Collapses strings and chars on a line to simple "" or '' blocks.
We nix strings first so we're not fooled by text like '"http://"'
Args:
elided: The line being processed.
Returns:
The line with collapsed strings.
"""
if _RE_PATTERN_INCLUDE.match(elided):
return elided
# Remove escaped characters first to make quote/single quote collapsing
# basic. Things that look like escaped characters shouldn't occur
# outside of strings and chars.
elided = _RE_PATTERN_CLEANSE_LINE_ESCAPES.sub('', elided)
# Replace quoted strings and digit separators. Both single quotes
# and double quotes are processed in the same loop, otherwise
# nested quotes wouldn't work.
collapsed = ''
while True:
# Find the first quote character
match = Match(r'^([^\'"]*)([\'"])(.*)$', elided)
if not match:
collapsed += elided
break
head, quote, tail = match.groups()
if quote == '"':
# Collapse double quoted strings
second_quote = tail.find('"')
if second_quote >= 0:
collapsed += head + '""'
elided = tail[second_quote + 1:]
else:
# Unmatched double quote, don't bother processing the rest
# of the line since this is probably a multiline string.
collapsed += elided
break
else:
# Found single quote, check nearby text to eliminate digit separators.
#
# There is no special handling for floating point here, because
# the integer/fractional/exponent parts would all be parsed
# correctly as long as there are digits on both sides of the
# separator. So we are fine as long as we don't see something
# like "0.'3" (gcc 4.9.0 will not allow this literal).
if Search(r'\b(?:0[bBxX]?|[1-9])[0-9a-fA-F]*$', head):
match_literal = Match(r'^((?:\'?[0-9a-zA-Z_])*)(.*)$', "'" + tail)
collapsed += head + match_literal.group(1).replace("'", '')
elided = match_literal.group(2)
else:
second_quote = tail.find('\'')
if second_quote >= 0:
collapsed += head + "''"
elided = tail[second_quote + 1:]
else:
# Unmatched single quote
collapsed += elided
break
return collapsed
def FindEndOfExpressionInLine(line, startpos, stack):
"""Find the position just after the end of current parenthesized expression.
Args:
line: a CleansedLines line.
startpos: start searching at this position.
stack: nesting stack at startpos.
Returns:
On finding matching end: (index just after matching end, None)
On finding an unclosed expression: (-1, None)
Otherwise: (-1, new stack at end of this line)
"""
for i in xrange(startpos, len(line)):
char = line[i]
if char in '([{':
# Found start of parenthesized expression, push to expression stack
stack.append(char)
elif char == '<':
# Found potential start of template argument list
if i > 0 and line[i - 1] == '<':
# Left shift operator
if stack and stack[-1] == '<':
stack.pop()
if not stack:
return (-1, None)
elif i > 0 and Search(r'\boperator\s*$', line[0:i]):
# operator<, don't add to stack
continue
else:
# Tentative start of template argument list
stack.append('<')
elif char in ')]}':
# Found end of parenthesized expression.
#
# If we are currently expecting a matching '>', the pending '<'
# must have been an operator. Remove them from expression stack.
while stack and stack[-1] == '<':
stack.pop()
if not stack:
return (-1, None)
if ((stack[-1] == '(' and char == ')') or
(stack[-1] == '[' and char == ']') or
(stack[-1] == '{' and char == '}')):
stack.pop()
if not stack:
return (i + 1, None)
else:
# Mismatched parentheses
return (-1, None)
elif char == '>':
# Found potential end of template argument list.
# Ignore "->" and operator functions
if (i > 0 and
(line[i - 1] == '-' or Search(r'\boperator\s*$', line[0:i - 1]))):
continue
# Pop the stack if there is a matching '<'. Otherwise, ignore
# this '>' since it must be an operator.
if stack:
if stack[-1] == '<':
stack.pop()
if not stack:
return (i + 1, None)
elif char == ';':
# Found something that look like end of statements. If we are currently
# expecting a '>', the matching '<' must have been an operator, since
# template argument list should not contain statements.
while stack and stack[-1] == '<':
stack.pop()
if not stack:
return (-1, None)
# Did not find end of expression or unbalanced parentheses on this line
return (-1, stack)
def CloseExpression(clean_lines, linenum, pos):
"""If input points to ( or { or [ or <, finds the position that closes it.
If lines[linenum][pos] points to a '(' or '{' or '[' or '<', finds the
linenum/pos that correspond to the closing of the expression.
TODO(unknown): cpplint spends a fair bit of time matching parentheses.
Ideally we would want to index all opening and closing parentheses once
and have CloseExpression be just a simple lookup, but due to preprocessor
tricks, this is not so easy.
Args:
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
pos: A position on the line.
Returns:
A tuple (line, linenum, pos) pointer *past* the closing brace, or
(line, len(lines), -1) if we never find a close. Note we ignore
strings and comments when matching; and the line we return is the
'cleansed' line at linenum.
"""
line = clean_lines.elided[linenum]
if (line[pos] not in '({[<') or Match(r'<[<=]', line[pos:]):
return (line, clean_lines.NumLines(), -1)
# Check first line
(end_pos, stack) = FindEndOfExpressionInLine(line, pos, [])
if end_pos > -1:
return (line, linenum, end_pos)
# Continue scanning forward
while stack and linenum < clean_lines.NumLines() - 1:
linenum += 1
line = clean_lines.elided[linenum]
(end_pos, stack) = FindEndOfExpressionInLine(line, 0, stack)
if end_pos > -1:
return (line, linenum, end_pos)
# Did not find end of expression before end of file, give up
return (line, clean_lines.NumLines(), -1)
def FindStartOfExpressionInLine(line, endpos, stack):
"""Find position at the matching start of current expression.
This is almost the reverse of FindEndOfExpressionInLine, but note
that the input position and returned position differs by 1.
Args:
line: a CleansedLines line.
endpos: start searching at this position.
stack: nesting stack at endpos.
Returns:
On finding matching start: (index at matching start, None)
On finding an unclosed expression: (-1, None)
Otherwise: (-1, new stack at beginning of this line)
"""
i = endpos
while i >= 0:
char = line[i]
if char in ')]}':
# Found end of expression, push to expression stack
stack.append(char)
elif char == '>':
# Found potential end of template argument list.
#
# Ignore it if it's a "->" or ">=" or "operator>"
if (i > 0 and
(line[i - 1] == '-' or
Match(r'\s>=\s', line[i - 1:]) or
Search(r'\boperator\s*$', line[0:i]))):
i -= 1
else:
stack.append('>')
elif char == '<':
# Found potential start of template argument list
if i > 0 and line[i - 1] == '<':
# Left shift operator
i -= 1
else:
# If there is a matching '>', we can pop the expression stack.
# Otherwise, ignore this '<' since it must be an operator.
if stack and stack[-1] == '>':
stack.pop()
if not stack:
return (i, None)
elif char in '([{':
# Found start of expression.
#
# If there are any unmatched '>' on the stack, they must be
# operators. Remove those.
while stack and stack[-1] == '>':
stack.pop()
if not stack:
return (-1, None)
if ((char == '(' and stack[-1] == ')') or
(char == '[' and stack[-1] == ']') or
(char == '{' and stack[-1] == '}')):
stack.pop()
if not stack:
return (i, None)
else:
# Mismatched parentheses
return (-1, None)
elif char == ';':
# Found something that look like end of statements. If we are currently
# expecting a '<', the matching '>' must have been an operator, since
# template argument list should not contain statements.
while stack and stack[-1] == '>':
stack.pop()
if not stack:
return (-1, None)
i -= 1
return (-1, stack)
def ReverseCloseExpression(clean_lines, linenum, pos):
"""If input points to ) or } or ] or >, finds the position that opens it.
If lines[linenum][pos] points to a ')' or '}' or ']' or '>', finds the
linenum/pos that correspond to the opening of the expression.
Args:
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
pos: A position on the line.
Returns:
A tuple (line, linenum, pos) pointer *at* the opening brace, or
(line, 0, -1) if we never find the matching opening brace. Note
we ignore strings and comments when matching; and the line we
return is the 'cleansed' line at linenum.
"""
line = clean_lines.elided[linenum]
if line[pos] not in ')}]>':
return (line, 0, -1)
# Check last line
(start_pos, stack) = FindStartOfExpressionInLine(line, pos, [])
if start_pos > -1:
return (line, linenum, start_pos)
# Continue scanning backward
while stack and linenum > 0:
linenum -= 1
line = clean_lines.elided[linenum]
(start_pos, stack) = FindStartOfExpressionInLine(line, len(line) - 1, stack)
if start_pos > -1:
return (line, linenum, start_pos)
# Did not find start of expression before beginning of file, give up
return (line, 0, -1)
def CheckForCopyright(filename, lines, error):
"""Logs an error if no Copyright message appears at the top of the file."""
# We'll say it should occur by line 10. Don't forget there's a
# placeholder line at the front.
for line in xrange(1, min(len(lines), 11)):
if re.search(r'Copyright', lines[line], re.I): break
else: # means no copyright line was found
error(filename, 0, 'legal/copyright', 5,
'No copyright message found. '
'You should have a line: "Copyright [year] <Copyright Owner>"')
def GetIndentLevel(line):
"""Return the number of leading spaces in line.
Args:
line: A string to check.
Returns:
An integer count of leading spaces, possibly zero.
"""
indent = Match(r'^( *)\S', line)
if indent:
return len(indent.group(1))
else:
return 0
def PathSplitToList(path):
"""Returns the path split into a list by the separator.
Args:
path: An absolute or relative path (e.g. '/a/b/c/' or '../a')
Returns:
A list of path components (e.g. ['a', 'b', 'c]).
"""
lst = []
while True:
(head, tail) = os.path.split(path)
if head == path: # absolute paths end
lst.append(head)
break
if tail == path: # relative paths end
lst.append(tail)
break
path = head
lst.append(tail)
lst.reverse()
return lst
def GetHeaderGuardCPPVariable(filename):
"""Returns the CPP variable that should be used as a header guard.
Args:
filename: The name of a C++ header file.
Returns:
The CPP variable that should be used as a header guard in the
named file.
"""
# Restores original filename in case that cpplint is invoked from Emacs's
# flymake.
filename = re.sub(r'_flymake\.h$', '.h', filename)
filename = re.sub(r'/\.flymake/([^/]*)$', r'/\1', filename)
# Replace 'c++' with 'cpp'.
filename = filename.replace('C++', 'cpp').replace('c++', 'cpp')
fileinfo = FileInfo(filename)
file_path_from_root = fileinfo.RepositoryName()
def FixupPathFromRoot():
if _root_debug:
sys.stderr.write("\n_root fixup, _root = '%s', repository name = '%s'\n"
%(_root, fileinfo.RepositoryName()))
# Process the file path with the --root flag if it was set.
if not _root:
if _root_debug:
sys.stderr.write("_root unspecified\n")
return file_path_from_root
def StripListPrefix(lst, prefix):
# f(['x', 'y'], ['w, z']) -> None (not a valid prefix)
if lst[:len(prefix)] != prefix:
return None
# f(['a, 'b', 'c', 'd'], ['a', 'b']) -> ['c', 'd']
return lst[(len(prefix)):]
# root behavior:
# --root=subdir , lstrips subdir from the header guard
maybe_path = StripListPrefix(PathSplitToList(file_path_from_root),
PathSplitToList(_root))
if _root_debug:
sys.stderr.write(("_root lstrip (maybe_path=%s, file_path_from_root=%s," +
" _root=%s)\n") %(maybe_path, file_path_from_root, _root))
if maybe_path:
return os.path.join(*maybe_path)
# --root=.. , will prepend the outer directory to the header guard
full_path = fileinfo.FullName()
root_abspath = os.path.abspath(_root)
maybe_path = StripListPrefix(PathSplitToList(full_path),
PathSplitToList(root_abspath))
if _root_debug:
sys.stderr.write(("_root prepend (maybe_path=%s, full_path=%s, " +
"root_abspath=%s)\n") %(maybe_path, full_path, root_abspath))
if maybe_path:
return os.path.join(*maybe_path)
if _root_debug:
sys.stderr.write("_root ignore, returning %s\n" %(file_path_from_root))
# --root=FAKE_DIR is ignored
return file_path_from_root
file_path_from_root = FixupPathFromRoot()
return re.sub(r'[^a-zA-Z0-9]', '_', file_path_from_root).upper() + '_'
def CheckForHeaderGuard(filename, clean_lines, error):
"""Checks that the file contains a header guard.
Logs an error if no #ifndef header guard is present. For other
headers, checks that the full pathname is used.
Args:
filename: The name of the C++ header file.
clean_lines: A CleansedLines instance containing the file.
error: The function to call with any errors found.
"""
# Don't check for header guards if there are error suppression
# comments somewhere in this file.
#
# Because this is silencing a warning for a nonexistent line, we
# only support the very specific NOLINT(build/header_guard) syntax,
# and not the general NOLINT or NOLINT(*) syntax.
raw_lines = clean_lines.lines_without_raw_strings
for i in raw_lines:
if Search(r'//\s*NOLINT\(build/header_guard\)', i):
return
cppvar = GetHeaderGuardCPPVariable(filename)
ifndef = ''
ifndef_linenum = 0
define = ''
endif = ''
endif_linenum = 0
for linenum, line in enumerate(raw_lines):
linesplit = line.split()
if len(linesplit) >= 2:
# find the first occurrence of #ifndef and #define, save arg
if not ifndef and linesplit[0] == '#ifndef':
# set ifndef to the header guard presented on the #ifndef line.
ifndef = linesplit[1]
ifndef_linenum = linenum
if not define and linesplit[0] == '#define':
define = linesplit[1]
# find the last occurrence of #endif, save entire line
if line.startswith('#endif'):
endif = line
endif_linenum = linenum
if not ifndef or not define or ifndef != define:
error(filename, 0, 'build/header_guard', 5,
'No #ifndef header guard found, suggested CPP variable is: %s' %
cppvar)
return
# The guard should be PATH_FILE_H_, but we also allow PATH_FILE_H__
# for backward compatibility.
if ifndef != cppvar:
error_level = 0
if ifndef != cppvar + '_':
error_level = 5
ParseNolintSuppressions(filename, raw_lines[ifndef_linenum], ifndef_linenum,
error)
error(filename, ifndef_linenum, 'build/header_guard', error_level,
'#ifndef header guard has wrong style, please use: %s' % cppvar)
# Check for "//" comments on endif line.
ParseNolintSuppressions(filename, raw_lines[endif_linenum], endif_linenum,
error)
match = Match(r'#endif\s*//\s*' + cppvar + r'(_)?\b', endif)
if match:
if match.group(1) == '_':
# Issue low severity warning for deprecated double trailing underscore
error(filename, endif_linenum, 'build/header_guard', 0,
'#endif line should be "#endif // %s"' % cppvar)
return
# Didn't find the corresponding "//" comment. If this file does not
# contain any "//" comments at all, it could be that the compiler
# only wants "/**/" comments, look for those instead.
no_single_line_comments = True
for i in xrange(1, len(raw_lines) - 1):
line = raw_lines[i]
if Match(r'^(?:(?:\'(?:\.|[^\'])*\')|(?:"(?:\.|[^"])*")|[^\'"])*//', line):
no_single_line_comments = False
break
if no_single_line_comments:
match = Match(r'#endif\s*/\*\s*' + cppvar + r'(_)?\s*\*/', endif)
if match:
if match.group(1) == '_':
# Low severity warning for double trailing underscore
error(filename, endif_linenum, 'build/header_guard', 0,
'#endif line should be "#endif /* %s */"' % cppvar)
return
# Didn't find anything
error(filename, endif_linenum, 'build/header_guard', 5,
'#endif line should be "#endif // %s"' % cppvar)
def CheckHeaderFileIncluded(filename, include_state, error):
"""Logs an error if a .cc file does not include its header."""
# Do not check test files
fileinfo = FileInfo(filename)
if Search(_TEST_FILE_SUFFIX, fileinfo.BaseName()):
return
headerfile = filename[0:len(filename) - len(fileinfo.Extension())] + '.h'
if not os.path.exists(headerfile):
return
headername = FileInfo(headerfile).RepositoryName()
first_include = 0
for section_list in include_state.include_list:
for f in section_list:
if headername in f[0] or f[0] in headername:
return
if not first_include:
first_include = f[1]
error(filename, first_include, 'build/include', 5,
'%s should include its header file %s' % (fileinfo.RepositoryName(),
headername))
def CheckForBadCharacters(filename, lines, error):
"""Logs an error for each line containing bad characters.
Two kinds of bad characters:
1. Unicode replacement characters: These indicate that either the file
contained invalid UTF-8 (likely) or Unicode replacement characters (which
it shouldn't). Note that it's possible for this to throw off line
numbering if the invalid UTF-8 occurred adjacent to a newline.
2. NUL bytes. These are problematic for some tools.
Args:
filename: The name of the current file.
lines: An array of strings, each representing a line of the file.
error: The function to call with any errors found.
"""
for linenum, line in enumerate(lines):
if u'\ufffd' in line:
error(filename, linenum, 'readability/utf8', 5,
'Line contains invalid UTF-8 (or Unicode replacement character).')
if '\0' in line:
error(filename, linenum, 'readability/nul', 5, 'Line contains NUL byte.')
def CheckForNewlineAtEOF(filename, lines, error):
"""Logs an error if there is no newline char at the end of the file.
Args:
filename: The name of the current file.
lines: An array of strings, each representing a line of the file.
error: The function to call with any errors found.
"""
# The array lines() was created by adding two newlines to the
# original file (go figure), then splitting on \n.
# To verify that the file ends in \n, we just have to make sure the
# last-but-two element of lines() exists and is empty.
if len(lines) < 3 or lines[-2]:
error(filename, len(lines) - 2, 'whitespace/ending_newline', 5,
'Could not find a newline character at the end of the file.')
def CheckForMultilineCommentsAndStrings(filename, clean_lines, linenum, error):
"""Logs an error if we see /* ... */ or "..." that extend past one line.
/* ... */ comments are legit inside macros, for one line.
Otherwise, we prefer // comments, so it's ok to warn about the
other. Likewise, it's ok for strings to extend across multiple
lines, as long as a line continuation character (backslash)
terminates each line. Although not currently prohibited by the C++
style guide, it's ugly and unnecessary. We don't do well with either
in this lint program, so we warn about both.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
# Remove all \\ (escaped backslashes) from the line. They are OK, and the
# second (escaped) slash may trigger later \" detection erroneously.
line = line.replace('\\\\', '')
if line.count('/*') > line.count('*/'):
error(filename, linenum, 'readability/multiline_comment', 5,
'Complex multi-line /*...*/-style comment found. '
'Lint may give bogus warnings. '
'Consider replacing these with //-style comments, '
'with #if 0...#endif, '
'or with more clearly structured multi-line comments.')
if (line.count('"') - line.count('\\"')) % 2:
error(filename, linenum, 'readability/multiline_string', 5,
'Multi-line string ("...") found. This lint script doesn\'t '
'do well with such strings, and may give bogus warnings. '
'Use C++11 raw strings or concatenation instead.')
# (non-threadsafe name, thread-safe alternative, validation pattern)
#
# The validation pattern is used to eliminate false positives such as:
# _rand(); // false positive due to substring match.
# ->rand(); // some member function rand().
# ACMRandom rand(seed); // some variable named rand.
# ISAACRandom rand(); // another variable named rand.
#
# Basically we require the return value of these functions to be used
# in some expression context on the same line by matching on some
# operator before the function name. This eliminates constructors and
# member function calls.
_UNSAFE_FUNC_PREFIX = r'(?:[-+*/=%^&|(<]\s*|>\s+)'
_THREADING_LIST = (
('asctime(', 'asctime_r(', _UNSAFE_FUNC_PREFIX + r'asctime\([^)]+\)'),
('ctime(', 'ctime_r(', _UNSAFE_FUNC_PREFIX + r'ctime\([^)]+\)'),
('getgrgid(', 'getgrgid_r(', _UNSAFE_FUNC_PREFIX + r'getgrgid\([^)]+\)'),
('getgrnam(', 'getgrnam_r(', _UNSAFE_FUNC_PREFIX + r'getgrnam\([^)]+\)'),
('getlogin(', 'getlogin_r(', _UNSAFE_FUNC_PREFIX + r'getlogin\(\)'),
('getpwnam(', 'getpwnam_r(', _UNSAFE_FUNC_PREFIX + r'getpwnam\([^)]+\)'),
('getpwuid(', 'getpwuid_r(', _UNSAFE_FUNC_PREFIX + r'getpwuid\([^)]+\)'),
('gmtime(', 'gmtime_r(', _UNSAFE_FUNC_PREFIX + r'gmtime\([^)]+\)'),
('localtime(', 'localtime_r(', _UNSAFE_FUNC_PREFIX + r'localtime\([^)]+\)'),
('rand(', 'rand_r(', _UNSAFE_FUNC_PREFIX + r'rand\(\)'),
('strtok(', 'strtok_r(',
_UNSAFE_FUNC_PREFIX + r'strtok\([^)]+\)'),
('ttyname(', 'ttyname_r(', _UNSAFE_FUNC_PREFIX + r'ttyname\([^)]+\)'),
)
def CheckPosixThreading(filename, clean_lines, linenum, error):
"""Checks for calls to thread-unsafe functions.
Much code has been originally written without consideration of
multi-threading. Also, engineers are relying on their old experience;
they have learned posix before threading extensions were added. These
tests guide the engineers to use thread-safe functions (when using
posix directly).
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
for single_thread_func, multithread_safe_func, pattern in _THREADING_LIST:
# Additional pattern matching check to confirm that this is the
# function we are looking for
if Search(pattern, line):
error(filename, linenum, 'runtime/threadsafe_fn', 2,
'Consider using ' + multithread_safe_func +
'...) instead of ' + single_thread_func +
'...) for improved thread safety.')
def CheckVlogArguments(filename, clean_lines, linenum, error):
"""Checks that VLOG() is only used for defining a logging level.
For example, VLOG(2) is correct. VLOG(INFO), VLOG(WARNING), VLOG(ERROR), and
VLOG(FATAL) are not.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
if Search(r'\bVLOG\((INFO|ERROR|WARNING|DFATAL|FATAL)\)', line):
error(filename, linenum, 'runtime/vlog', 5,
'VLOG() should be used with numeric verbosity level. '
'Use LOG() if you want symbolic severity levels.')
# Matches invalid increment: *count++, which moves pointer instead of
# incrementing a value.
_RE_PATTERN_INVALID_INCREMENT = re.compile(
r'^\s*\*\w+(\+\+|--);')
def CheckInvalidIncrement(filename, clean_lines, linenum, error):
"""Checks for invalid increment *count++.
For example following function:
void increment_counter(int* count) {
*count++;
}
is invalid, because it effectively does count++, moving pointer, and should
be replaced with ++*count, (*count)++ or *count += 1.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
if _RE_PATTERN_INVALID_INCREMENT.match(line):
error(filename, linenum, 'runtime/invalid_increment', 5,
'Changing pointer instead of value (or unused value of operator*).')
def IsMacroDefinition(clean_lines, linenum):
if Search(r'^#define', clean_lines[linenum]):
return True
if linenum > 0 and Search(r'\\$', clean_lines[linenum - 1]):
return True
return False
def IsForwardClassDeclaration(clean_lines, linenum):
return Match(r'^\s*(\btemplate\b)*.*class\s+\w+;\s*$', clean_lines[linenum])
class _BlockInfo(object):
"""Stores information about a generic block of code."""
def __init__(self, linenum, seen_open_brace):
self.starting_linenum = linenum
self.seen_open_brace = seen_open_brace
self.open_parentheses = 0
self.inline_asm = _NO_ASM
self.check_namespace_indentation = False
def CheckBegin(self, filename, clean_lines, linenum, error):
"""Run checks that applies to text up to the opening brace.
This is mostly for checking the text after the class identifier
and the "{", usually where the base class is specified. For other
blocks, there isn't much to check, so we always pass.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
pass
def CheckEnd(self, filename, clean_lines, linenum, error):
"""Run checks that applies to text after the closing brace.
This is mostly used for checking end of namespace comments.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
pass
def IsBlockInfo(self):
"""Returns true if this block is a _BlockInfo.
This is convenient for verifying that an object is an instance of
a _BlockInfo, but not an instance of any of the derived classes.
Returns:
True for this class, False for derived classes.
"""
return self.__class__ == _BlockInfo
class _ExternCInfo(_BlockInfo):
"""Stores information about an 'extern "C"' block."""
def __init__(self, linenum):
_BlockInfo.__init__(self, linenum, True)
class _ClassInfo(_BlockInfo):
"""Stores information about a class."""
def __init__(self, name, class_or_struct, clean_lines, linenum):
_BlockInfo.__init__(self, linenum, False)
self.name = name
self.is_derived = False
self.check_namespace_indentation = True
if class_or_struct == 'struct':
self.access = 'public'
self.is_struct = True
else:
self.access = 'private'
self.is_struct = False
# Remember initial indentation level for this class. Using raw_lines here
# instead of elided to account for leading comments.
self.class_indent = GetIndentLevel(clean_lines.raw_lines[linenum])
# Try to find the end of the class. This will be confused by things like:
# class A {
# } *x = { ...
#
# But it's still good enough for CheckSectionSpacing.
self.last_line = 0
depth = 0
for i in range(linenum, clean_lines.NumLines()):
line = clean_lines.elided[i]
depth += line.count('{') - line.count('}')
if not depth:
self.last_line = i
break
def CheckBegin(self, filename, clean_lines, linenum, error):
# Look for a bare ':'
if Search('(^|[^:]):($|[^:])', clean_lines.elided[linenum]):
self.is_derived = True
def CheckEnd(self, filename, clean_lines, linenum, error):
# If there is a DISALLOW macro, it should appear near the end of
# the class.
seen_last_thing_in_class = False
for i in xrange(linenum - 1, self.starting_linenum, -1):
match = Search(
r'\b(DISALLOW_COPY_AND_ASSIGN|DISALLOW_IMPLICIT_CONSTRUCTORS)\(' +
self.name + r'\)',
clean_lines.elided[i])
if match:
if seen_last_thing_in_class:
error(filename, i, 'readability/constructors', 3,
match.group(1) + ' should be the last thing in the class')
break
if not Match(r'^\s*$', clean_lines.elided[i]):
seen_last_thing_in_class = True
# Check that closing brace is aligned with beginning of the class.
# Only do this if the closing brace is indented by only whitespaces.
# This means we will not check single-line class definitions.
indent = Match(r'^( *)\}', clean_lines.elided[linenum])
if indent and len(indent.group(1)) != self.class_indent:
if self.is_struct:
parent = 'struct ' + self.name
else:
parent = 'class ' + self.name
error(filename, linenum, 'whitespace/indent', 3,
'Closing brace should be aligned with beginning of %s' % parent)
class _NamespaceInfo(_BlockInfo):
"""Stores information about a namespace."""
def __init__(self, name, linenum):
_BlockInfo.__init__(self, linenum, False)
self.name = name or ''
self.check_namespace_indentation = True
def CheckEnd(self, filename, clean_lines, linenum, error):
"""Check end of namespace comments."""
line = clean_lines.raw_lines[linenum]
# Check how many lines is enclosed in this namespace. Don't issue
# warning for missing namespace comments if there aren't enough
# lines. However, do apply checks if there is already an end of
# namespace comment and it's incorrect.
#
# TODO(unknown): We always want to check end of namespace comments
# if a namespace is large, but sometimes we also want to apply the
# check if a short namespace contained nontrivial things (something
# other than forward declarations). There is currently no logic on
# deciding what these nontrivial things are, so this check is
# triggered by namespace size only, which works most of the time.
if (linenum - self.starting_linenum < 10
and not Match(r'^\s*};*\s*(//|/\*).*\bnamespace\b', line)):
return
# Look for matching comment at end of namespace.
#
# Note that we accept C style "/* */" comments for terminating
# namespaces, so that code that terminate namespaces inside
# preprocessor macros can be cpplint clean.
#
# We also accept stuff like "// end of namespace <name>." with the
# period at the end.
#
# Besides these, we don't accept anything else, otherwise we might
# get false negatives when existing comment is a substring of the
# expected namespace.
if self.name:
# Named namespace
if not Match((r'^\s*};*\s*(//|/\*).*\bnamespace\s+' +
re.escape(self.name) + r'[\*/\.\\\s]*$'),
line):
error(filename, linenum, 'readability/namespace', 5,
'Namespace should be terminated with "// namespace %s"' %
self.name)
else:
# Anonymous namespace
if not Match(r'^\s*};*\s*(//|/\*).*\bnamespace[\*/\.\\\s]*$', line):
# If "// namespace anonymous" or "// anonymous namespace (more text)",
# mention "// anonymous namespace" as an acceptable form
if Match(r'^\s*}.*\b(namespace anonymous|anonymous namespace)\b', line):
error(filename, linenum, 'readability/namespace', 5,
'Anonymous namespace should be terminated with "// namespace"'
' or "// anonymous namespace"')
else:
error(filename, linenum, 'readability/namespace', 5,
'Anonymous namespace should be terminated with "// namespace"')
class _PreprocessorInfo(object):
"""Stores checkpoints of nesting stacks when #if/#else is seen."""
def __init__(self, stack_before_if):
# The entire nesting stack before #if
self.stack_before_if = stack_before_if
# The entire nesting stack up to #else
self.stack_before_else = []
# Whether we have already seen #else or #elif
self.seen_else = False
class NestingState(object):
"""Holds states related to parsing braces."""
def __init__(self):
# Stack for tracking all braces. An object is pushed whenever we
# see a "{", and popped when we see a "}". Only 3 types of
# objects are possible:
# - _ClassInfo: a class or struct.
# - _NamespaceInfo: a namespace.
# - _BlockInfo: some other type of block.
self.stack = []
# Top of the previous stack before each Update().
#
# Because the nesting_stack is updated at the end of each line, we
# had to do some convoluted checks to find out what is the current
# scope at the beginning of the line. This check is simplified by
# saving the previous top of nesting stack.
#
# We could save the full stack, but we only need the top. Copying
# the full nesting stack would slow down cpplint by ~10%.
self.previous_stack_top = []
# Stack of _PreprocessorInfo objects.
self.pp_stack = []
def SeenOpenBrace(self):
"""Check if we have seen the opening brace for the innermost block.
Returns:
True if we have seen the opening brace, False if the innermost
block is still expecting an opening brace.
"""
return (not self.stack) or self.stack[-1].seen_open_brace
def InNamespaceBody(self):
"""Check if we are currently one level inside a namespace body.
Returns:
True if top of the stack is a namespace block, False otherwise.
"""
return self.stack and isinstance(self.stack[-1], _NamespaceInfo)
def InExternC(self):
"""Check if we are currently one level inside an 'extern "C"' block.
Returns:
True if top of the stack is an extern block, False otherwise.
"""
return self.stack and isinstance(self.stack[-1], _ExternCInfo)
def InClassDeclaration(self):
"""Check if we are currently one level inside a class or struct declaration.
Returns:
True if top of the stack is a class/struct, False otherwise.
"""
return self.stack and isinstance(self.stack[-1], _ClassInfo)
def InAsmBlock(self):
"""Check if we are currently one level inside an inline ASM block.
Returns:
True if the top of the stack is a block containing inline ASM.
"""
return self.stack and self.stack[-1].inline_asm != _NO_ASM
def InTemplateArgumentList(self, clean_lines, linenum, pos):
"""Check if current position is inside template argument list.
Args:
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
pos: position just after the suspected template argument.
Returns:
True if (linenum, pos) is inside template arguments.
"""
while linenum < clean_lines.NumLines():
# Find the earliest character that might indicate a template argument
line = clean_lines.elided[linenum]
match = Match(r'^[^{};=\[\]\.<>]*(.)', line[pos:])
if not match:
linenum += 1
pos = 0
continue
token = match.group(1)
pos += len(match.group(0))
# These things do not look like template argument list:
# class Suspect {
# class Suspect x; }
if token in ('{', '}', ';'): return False
# These things look like template argument list:
# template <class Suspect>
# template <class Suspect = default_value>
# template <class Suspect[]>
# template <class Suspect...>
if token in ('>', '=', '[', ']', '.'): return True
# Check if token is an unmatched '<'.
# If not, move on to the next character.
if token != '<':
pos += 1
if pos >= len(line):
linenum += 1
pos = 0
continue
# We can't be sure if we just find a single '<', and need to
# find the matching '>'.
(_, end_line, end_pos) = CloseExpression(clean_lines, linenum, pos - 1)
if end_pos < 0:
# Not sure if template argument list or syntax error in file
return False
linenum = end_line
pos = end_pos
return False
def UpdatePreprocessor(self, line):
"""Update preprocessor stack.
We need to handle preprocessors due to classes like this:
#ifdef SWIG
struct ResultDetailsPageElementExtensionPoint {
#else
struct ResultDetailsPageElementExtensionPoint : public Extension {
#endif
We make the following assumptions (good enough for most files):
- Preprocessor condition evaluates to true from #if up to first
#else/#elif/#endif.
- Preprocessor condition evaluates to false from #else/#elif up
to #endif. We still perform lint checks on these lines, but
these do not affect nesting stack.
Args:
line: current line to check.
"""
if Match(r'^\s*#\s*(if|ifdef|ifndef)\b', line):
# Beginning of #if block, save the nesting stack here. The saved
# stack will allow us to restore the parsing state in the #else case.
self.pp_stack.append(_PreprocessorInfo(copy.deepcopy(self.stack)))
elif Match(r'^\s*#\s*(else|elif)\b', line):
# Beginning of #else block
if self.pp_stack:
if not self.pp_stack[-1].seen_else:
# This is the first #else or #elif block. Remember the
# whole nesting stack up to this point. This is what we
# keep after the #endif.
self.pp_stack[-1].seen_else = True
self.pp_stack[-1].stack_before_else = copy.deepcopy(self.stack)
# Restore the stack to how it was before the #if
self.stack = copy.deepcopy(self.pp_stack[-1].stack_before_if)
else:
# TODO(unknown): unexpected #else, issue warning?
pass
elif Match(r'^\s*#\s*endif\b', line):
# End of #if or #else blocks.
if self.pp_stack:
# If we saw an #else, we will need to restore the nesting
# stack to its former state before the #else, otherwise we
# will just continue from where we left off.
if self.pp_stack[-1].seen_else:
# Here we can just use a shallow copy since we are the last
# reference to it.
self.stack = self.pp_stack[-1].stack_before_else
# Drop the corresponding #if
self.pp_stack.pop()
else:
# TODO(unknown): unexpected #endif, issue warning?
pass
# TODO(unknown): Update() is too long, but we will refactor later.
def Update(self, filename, clean_lines, linenum, error):
"""Update nesting state with current line.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
# Remember top of the previous nesting stack.
#
# The stack is always pushed/popped and not modified in place, so
# we can just do a shallow copy instead of copy.deepcopy. Using
# deepcopy would slow down cpplint by ~28%.
if self.stack:
self.previous_stack_top = self.stack[-1]
else:
self.previous_stack_top = None
# Update pp_stack
self.UpdatePreprocessor(line)
# Count parentheses. This is to avoid adding struct arguments to
# the nesting stack.
if self.stack:
inner_block = self.stack[-1]
depth_change = line.count('(') - line.count(')')
inner_block.open_parentheses += depth_change
# Also check if we are starting or ending an inline assembly block.
if inner_block.inline_asm in (_NO_ASM, _END_ASM):
if (depth_change != 0 and
inner_block.open_parentheses == 1 and
_MATCH_ASM.match(line)):
# Enter assembly block
inner_block.inline_asm = _INSIDE_ASM
else:
# Not entering assembly block. If previous line was _END_ASM,
# we will now shift to _NO_ASM state.
inner_block.inline_asm = _NO_ASM
elif (inner_block.inline_asm == _INSIDE_ASM and
inner_block.open_parentheses == 0):
# Exit assembly block
inner_block.inline_asm = _END_ASM
# Consume namespace declaration at the beginning of the line. Do
# this in a loop so that we catch same line declarations like this:
# namespace proto2 { namespace bridge { class MessageSet; } }
while True:
# Match start of namespace. The "\b\s*" below catches namespace
# declarations even if it weren't followed by a whitespace, this
# is so that we don't confuse our namespace checker. The
# missing spaces will be flagged by CheckSpacing.
namespace_decl_match = Match(r'^\s*namespace\b\s*([:\w]+)?(.*)$', line)
if not namespace_decl_match:
break
new_namespace = _NamespaceInfo(namespace_decl_match.group(1), linenum)
self.stack.append(new_namespace)
line = namespace_decl_match.group(2)
if line.find('{') != -1:
new_namespace.seen_open_brace = True
line = line[line.find('{') + 1:]
# Look for a class declaration in whatever is left of the line
# after parsing namespaces. The regexp accounts for decorated classes
# such as in:
# class LOCKABLE API Object {
# };
class_decl_match = Match(
r'^(\s*(?:template\s*<[\w\s<>,:]*>\s*)?'
r'(class|struct)\s+(?:[A-Z_]+\s+)*(\w+(?:::\w+)*))'
r'(.*)$', line)
if (class_decl_match and
(not self.stack or self.stack[-1].open_parentheses == 0)):
# We do not want to accept classes that are actually template arguments:
# template <class Ignore1,
# class Ignore2 = Default<Args>,
# template <Args> class Ignore3>
# void Function() {};
#
# To avoid template argument cases, we scan forward and look for
# an unmatched '>'. If we see one, assume we are inside a
# template argument list.
end_declaration = len(class_decl_match.group(1))
if not self.InTemplateArgumentList(clean_lines, linenum, end_declaration):
self.stack.append(_ClassInfo(
class_decl_match.group(3), class_decl_match.group(2),
clean_lines, linenum))
line = class_decl_match.group(4)
# If we have not yet seen the opening brace for the innermost block,
# run checks here.
if not self.SeenOpenBrace():
self.stack[-1].CheckBegin(filename, clean_lines, linenum, error)
# Update access control if we are inside a class/struct
if self.stack and isinstance(self.stack[-1], _ClassInfo):
classinfo = self.stack[-1]
access_match = Match(
r'^(.*)\b(public|private|protected|signals)(\s+(?:slots\s*)?)?'
r':(?:[^:]|$)',
line)
if access_match:
classinfo.access = access_match.group(2)
# Check that access keywords are indented +1 space. Skip this
# check if the keywords are not preceded by whitespaces.
indent = access_match.group(1)
if (len(indent) != classinfo.class_indent + 1 and
Match(r'^\s*$', indent)):
if classinfo.is_struct:
parent = 'struct ' + classinfo.name
else:
parent = 'class ' + classinfo.name
slots = ''
if access_match.group(3):
slots = access_match.group(3)
error(filename, linenum, 'whitespace/indent', 3,
'%s%s: should be indented +1 space inside %s' % (
access_match.group(2), slots, parent))
# Consume braces or semicolons from what's left of the line
while True:
# Match first brace, semicolon, or closed parenthesis.
matched = Match(r'^[^{;)}]*([{;)}])(.*)$', line)
if not matched:
break
token = matched.group(1)
if token == '{':
# If namespace or class hasn't seen a opening brace yet, mark
# namespace/class head as complete. Push a new block onto the
# stack otherwise.
if not self.SeenOpenBrace():
self.stack[-1].seen_open_brace = True
elif Match(r'^extern\s*"[^"]*"\s*\{', line):
self.stack.append(_ExternCInfo(linenum))
else:
self.stack.append(_BlockInfo(linenum, True))
if _MATCH_ASM.match(line):
self.stack[-1].inline_asm = _BLOCK_ASM
elif token == ';' or token == ')':
# If we haven't seen an opening brace yet, but we already saw
# a semicolon, this is probably a forward declaration. Pop
# the stack for these.
#
# Similarly, if we haven't seen an opening brace yet, but we
# already saw a closing parenthesis, then these are probably
# function arguments with extra "class" or "struct" keywords.
# Also pop these stack for these.
if not self.SeenOpenBrace():
self.stack.pop()
else: # token == '}'
# Perform end of block checks and pop the stack.
if self.stack:
self.stack[-1].CheckEnd(filename, clean_lines, linenum, error)
self.stack.pop()
line = matched.group(2)
def InnermostClass(self):
"""Get class info on the top of the stack.
Returns:
A _ClassInfo object if we are inside a class, or None otherwise.
"""
for i in range(len(self.stack), 0, -1):
classinfo = self.stack[i - 1]
if isinstance(classinfo, _ClassInfo):
return classinfo
return None
def CheckCompletedBlocks(self, filename, error):
"""Checks that all classes and namespaces have been completely parsed.
Call this when all lines in a file have been processed.
Args:
filename: The name of the current file.
error: The function to call with any errors found.
"""
# Note: This test can result in false positives if #ifdef constructs
# get in the way of brace matching. See the testBuildClass test in
# cpplint_unittest.py for an example of this.
for obj in self.stack:
if isinstance(obj, _ClassInfo):
error(filename, obj.starting_linenum, 'build/class', 5,
'Failed to find complete declaration of class %s' %
obj.name)
elif isinstance(obj, _NamespaceInfo):
error(filename, obj.starting_linenum, 'build/namespaces', 5,
'Failed to find complete declaration of namespace %s' %
obj.name)
def CheckForNonStandardConstructs(filename, clean_lines, linenum,
nesting_state, error):
r"""Logs an error if we see certain non-ANSI constructs ignored by gcc-2.
Complain about several constructs which gcc-2 accepts, but which are
not standard C++. Warning about these in lint is one way to ease the
transition to new compilers.
- put storage class first (e.g. "static const" instead of "const static").
- "%lld" instead of %qd" in printf-type functions.
- "%1$d" is non-standard in printf-type functions.
- "\%" is an undefined character escape sequence.
- text after #endif is not allowed.
- invalid inner-style forward declaration.
- >? and <? operators, and their >?= and <?= cousins.
Additionally, check for constructor/destructor style violations and reference
members, as it is very convenient to do so while checking for
gcc-2 compliance.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
nesting_state: A NestingState instance which maintains information about
the current stack of nested blocks being parsed.
error: A callable to which errors are reported, which takes 4 arguments:
filename, line number, error level, and message
"""
# Remove comments from the line, but leave in strings for now.
line = clean_lines.lines[linenum]
if Search(r'printf\s*\(.*".*%[-+ ]?\d*q', line):
error(filename, linenum, 'runtime/printf_format', 3,
'%q in format strings is deprecated. Use %ll instead.')
if Search(r'printf\s*\(.*".*%\d+\$', line):
error(filename, linenum, 'runtime/printf_format', 2,
'%N$ formats are unconventional. Try rewriting to avoid them.')
# Remove escaped backslashes before looking for undefined escapes.
line = line.replace('\\\\', '')
if Search(r'("|\').*\\(%|\[|\(|{)', line):
error(filename, linenum, 'build/printf_format', 3,
'%, [, (, and { are undefined character escapes. Unescape them.')
# For the rest, work with both comments and strings removed.
line = clean_lines.elided[linenum]
if Search(r'\b(const|volatile|void|char|short|int|long'
r'|float|double|signed|unsigned'
r'|schar|u?int8|u?int16|u?int32|u?int64)'
r'\s+(register|static|extern|typedef)\b',
line):
error(filename, linenum, 'build/storage_class', 5,
'Storage-class specifier (static, extern, typedef, etc) should be '
'at the beginning of the declaration.')
if Match(r'\s*#\s*endif\s*[^/\s]+', line):
error(filename, linenum, 'build/endif_comment', 5,
'Uncommented text after #endif is non-standard. Use a comment.')
if Match(r'\s*class\s+(\w+\s*::\s*)+\w+\s*;', line):
error(filename, linenum, 'build/forward_decl', 5,
'Inner-style forward declarations are invalid. Remove this line.')
if Search(r'(\w+|[+-]?\d+(\.\d*)?)\s*(<|>)\?=?\s*(\w+|[+-]?\d+)(\.\d*)?',
line):
error(filename, linenum, 'build/deprecated', 3,
'>? and <? (max and min) operators are non-standard and deprecated.')
if Search(r'^\s*const\s*string\s*&\s*\w+\s*;', line):
# TODO(unknown): Could it be expanded safely to arbitrary references,
# without triggering too many false positives? The first
# attempt triggered 5 warnings for mostly benign code in the regtest, hence
# the restriction.
# Here's the original regexp, for the reference:
# type_name = r'\w+((\s*::\s*\w+)|(\s*<\s*\w+?\s*>))?'
# r'\s*const\s*' + type_name + '\s*&\s*\w+\s*;'
error(filename, linenum, 'runtime/member_string_references', 2,
'const string& members are dangerous. It is much better to use '
'alternatives, such as pointers or simple constants.')
# Everything else in this function operates on class declarations.
# Return early if the top of the nesting stack is not a class, or if
# the class head is not completed yet.
classinfo = nesting_state.InnermostClass()
if not classinfo or not classinfo.seen_open_brace:
return
# The class may have been declared with namespace or classname qualifiers.
# The constructor and destructor will not have those qualifiers.
base_classname = classinfo.name.split('::')[-1]
# Look for single-argument constructors that aren't marked explicit.
# Technically a valid construct, but against style.
explicit_constructor_match = Match(
r'\s+(?:(?:inline|constexpr)\s+)*(explicit\s+)?'
r'(?:(?:inline|constexpr)\s+)*%s\s*'
r'\(((?:[^()]|\([^()]*\))*)\)'
% re.escape(base_classname),
line)
if explicit_constructor_match:
is_marked_explicit = explicit_constructor_match.group(1)
if not explicit_constructor_match.group(2):
constructor_args = []
else:
constructor_args = explicit_constructor_match.group(2).split(',')
# collapse arguments so that commas in template parameter lists and function
# argument parameter lists don't split arguments in two
i = 0
while i < len(constructor_args):
constructor_arg = constructor_args[i]
while (constructor_arg.count('<') > constructor_arg.count('>') or
constructor_arg.count('(') > constructor_arg.count(')')):
constructor_arg += ',' + constructor_args[i + 1]
del constructor_args[i + 1]
constructor_args[i] = constructor_arg
i += 1
defaulted_args = [arg for arg in constructor_args if '=' in arg]
noarg_constructor = (not constructor_args or # empty arg list
# 'void' arg specifier
(len(constructor_args) == 1 and
constructor_args[0].strip() == 'void'))
onearg_constructor = ((len(constructor_args) == 1 and # exactly one arg
not noarg_constructor) or
# all but at most one arg defaulted
(len(constructor_args) >= 1 and
not noarg_constructor and
len(defaulted_args) >= len(constructor_args) - 1))
initializer_list_constructor = bool(
onearg_constructor and
Search(r'\bstd\s*::\s*initializer_list\b', constructor_args[0]))
copy_constructor = bool(
onearg_constructor and
Match(r'(const\s+)?%s(\s*<[^>]*>)?(\s+const)?\s*(?:<\w+>\s*)?&'
% re.escape(base_classname), constructor_args[0].strip()))
if (not is_marked_explicit and
onearg_constructor and
not initializer_list_constructor and
not copy_constructor):
if defaulted_args:
error(filename, linenum, 'runtime/explicit', 5,
'Constructors callable with one argument '
'should be marked explicit.')
else:
error(filename, linenum, 'runtime/explicit', 5,
'Single-parameter constructors should be marked explicit.')
elif is_marked_explicit and not onearg_constructor:
if noarg_constructor:
error(filename, linenum, 'runtime/explicit', 5,
'Zero-parameter constructors should not be marked explicit.')
def CheckSpacingForFunctionCall(filename, clean_lines, linenum, error):
"""Checks for the correctness of various spacing around function calls.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
# Since function calls often occur inside if/for/while/switch
# expressions - which have their own, more liberal conventions - we
# first see if we should be looking inside such an expression for a
# function call, to which we can apply more strict standards.
fncall = line # if there's no control flow construct, look at whole line
for pattern in (r'\bif\s*\((.*)\)\s*{',
r'\bfor\s*\((.*)\)\s*{',
r'\bwhile\s*\((.*)\)\s*[{;]',
r'\bswitch\s*\((.*)\)\s*{'):
match = Search(pattern, line)
if match:
fncall = match.group(1) # look inside the parens for function calls
break
# Except in if/for/while/switch, there should never be space
# immediately inside parens (eg "f( 3, 4 )"). We make an exception
# for nested parens ( (a+b) + c ). Likewise, there should never be
# a space before a ( when it's a function argument. I assume it's a
# function argument when the char before the whitespace is legal in
# a function name (alnum + _) and we're not starting a macro. Also ignore
# pointers and references to arrays and functions coz they're too tricky:
# we use a very simple way to recognize these:
# " (something)(maybe-something)" or
# " (something)(maybe-something," or
# " (something)[something]"
# Note that we assume the contents of [] to be short enough that
# they'll never need to wrap.
if ( # Ignore control structures.
not Search(r'\b(if|for|while|switch|return|new|delete|catch|sizeof)\b',
fncall) and
# Ignore pointers/references to functions.
not Search(r' \([^)]+\)\([^)]*(\)|,$)', fncall) and
# Ignore pointers/references to arrays.
not Search(r' \([^)]+\)\[[^\]]+\]', fncall)):
if Search(r'\w\s*\(\s(?!\s*\\$)', fncall): # a ( used for a fn call
error(filename, linenum, 'whitespace/parens', 4,
'Extra space after ( in function call')
elif Search(r'\(\s+(?!(\s*\\)|\()', fncall):
error(filename, linenum, 'whitespace/parens', 2,
'Extra space after (')
if (Search(r'\w\s+\(', fncall) and
not Search(r'_{0,2}asm_{0,2}\s+_{0,2}volatile_{0,2}\s+\(', fncall) and
not Search(r'#\s*define|typedef|using\s+\w+\s*=', fncall) and
not Search(r'\w\s+\((\w+::)*\*\w+\)\(', fncall) and
not Search(r'\bcase\s+\(', fncall)):
# TODO(unknown): Space after an operator function seem to be a common
# error, silence those for now by restricting them to highest verbosity.
if Search(r'\boperator_*\b', line):
error(filename, linenum, 'whitespace/parens', 0,
'Extra space before ( in function call')
else:
error(filename, linenum, 'whitespace/parens', 4,
'Extra space before ( in function call')
# If the ) is followed only by a newline or a { + newline, assume it's
# part of a control statement (if/while/etc), and don't complain
if Search(r'[^)]\s+\)\s*[^{\s]', fncall):
# If the closing parenthesis is preceded by only whitespaces,
# try to give a more descriptive error message.
if Search(r'^\s+\)', fncall):
error(filename, linenum, 'whitespace/parens', 2,
'Closing ) should be moved to the previous line')
else:
error(filename, linenum, 'whitespace/parens', 2,
'Extra space before )')
def IsBlankLine(line):
"""Returns true if the given line is blank.
We consider a line to be blank if the line is empty or consists of
only white spaces.
Args:
line: A line of a string.
Returns:
True, if the given line is blank.
"""
return not line or line.isspace()
def CheckForNamespaceIndentation(filename, nesting_state, clean_lines, line,
error):
is_namespace_indent_item = (
len(nesting_state.stack) > 1 and
nesting_state.stack[-1].check_namespace_indentation and
isinstance(nesting_state.previous_stack_top, _NamespaceInfo) and
nesting_state.previous_stack_top == nesting_state.stack[-2])
if ShouldCheckNamespaceIndentation(nesting_state, is_namespace_indent_item,
clean_lines.elided, line):
CheckItemIndentationInNamespace(filename, clean_lines.elided,
line, error)
def CheckForFunctionLengths(filename, clean_lines, linenum,
function_state, error):
"""Reports for long function bodies.
For an overview why this is done, see:
https://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Write_Short_Functions
Uses a simplistic algorithm assuming other style guidelines
(especially spacing) are followed.
Only checks unindented functions, so class members are unchecked.
Trivial bodies are unchecked, so constructors with huge initializer lists
may be missed.
Blank/comment lines are not counted so as to avoid encouraging the removal
of vertical space and comments just to get through a lint check.
NOLINT *on the last line of a function* disables this check.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
function_state: Current function name and lines in body so far.
error: The function to call with any errors found.
"""
lines = clean_lines.lines
line = lines[linenum]
joined_line = ''
starting_func = False
regexp = r'(\w(\w|::|\*|\&|\s)*)\(' # decls * & space::name( ...
match_result = Match(regexp, line)
if match_result:
# If the name is all caps and underscores, figure it's a macro and
# ignore it, unless it's TEST or TEST_F.
function_name = match_result.group(1).split()[-1]
if function_name == 'TEST' or function_name == 'TEST_F' or (
not Match(r'[A-Z_]+$', function_name)):
starting_func = True
if starting_func:
body_found = False
for start_linenum in xrange(linenum, clean_lines.NumLines()):
start_line = lines[start_linenum]
joined_line += ' ' + start_line.lstrip()
if Search(r'(;|})', start_line): # Declarations and trivial functions
body_found = True
break # ... ignore
elif Search(r'{', start_line):
body_found = True
function = Search(r'((\w|:)*)\(', line).group(1)
if Match(r'TEST', function): # Handle TEST... macros
parameter_regexp = Search(r'(\(.*\))', joined_line)
if parameter_regexp: # Ignore bad syntax
function += parameter_regexp.group(1)
else:
function += '()'
function_state.Begin(function)
break
if not body_found:
# No body for the function (or evidence of a non-function) was found.
error(filename, linenum, 'readability/fn_size', 5,
'Lint failed to find start of function body.')
elif Match(r'^\}\s*$', line): # function end
function_state.Check(error, filename, linenum)
function_state.End()
elif not Match(r'^\s*$', line):
function_state.Count() # Count non-blank/non-comment lines.
_RE_PATTERN_TODO = re.compile(r'^//(\s*)TODO(\(.+?\))?:?(\s|$)?')
def CheckComment(line, filename, linenum, next_line_start, error):
"""Checks for common mistakes in comments.
Args:
line: The line in question.
filename: The name of the current file.
linenum: The number of the line to check.
next_line_start: The first non-whitespace column of the next line.
error: The function to call with any errors found.
"""
commentpos = line.find('//')
if commentpos != -1:
# Check if the // may be in quotes. If so, ignore it
if re.sub(r'\\.', '', line[0:commentpos]).count('"') % 2 == 0:
# Allow one space for new scopes, two spaces otherwise:
if (not (Match(r'^.*{ *//', line) and next_line_start == commentpos) and
((commentpos >= 1 and
line[commentpos-1] not in string.whitespace) or
(commentpos >= 2 and
line[commentpos-2] not in string.whitespace))):
error(filename, linenum, 'whitespace/comments', 2,
'At least two spaces is best between code and comments')
# Checks for common mistakes in TODO comments.
comment = line[commentpos:]
match = _RE_PATTERN_TODO.match(comment)
if match:
# One whitespace is correct; zero whitespace is handled elsewhere.
leading_whitespace = match.group(1)
if len(leading_whitespace) > 1:
error(filename, linenum, 'whitespace/todo', 2,
'Too many spaces before TODO')
username = match.group(2)
if not username:
error(filename, linenum, 'readability/todo', 2,
'Missing username in TODO; it should look like '
'"// TODO(my_username): Stuff."')
middle_whitespace = match.group(3)
# Comparisons made explicit for correctness -- pylint: disable=g-explicit-bool-comparison
if middle_whitespace != ' ' and middle_whitespace != '':
error(filename, linenum, 'whitespace/todo', 2,
'TODO(my_username) should be followed by a space')
# If the comment contains an alphanumeric character, there
# should be a space somewhere between it and the // unless
# it's a /// or //! Doxygen comment.
if (Match(r'//[^ ]*\w', comment) and
not Match(r'(///|//\!)(\s+|$)', comment)):
error(filename, linenum, 'whitespace/comments', 4,
'Should have a space between // and comment')
def CheckSpacing(filename, clean_lines, linenum, nesting_state, error):
"""Checks for the correctness of various spacing issues in the code.
Things we check for: spaces around operators, spaces after
if/for/while/switch, no spaces around parens in function calls, two
spaces between code and comment, don't start a block with a blank
line, don't end a function with a blank line, don't add a blank line
after public/protected/private, don't have too many blank lines in a row.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
nesting_state: A NestingState instance which maintains information about
the current stack of nested blocks being parsed.
error: The function to call with any errors found.
"""
# Don't use "elided" lines here, otherwise we can't check commented lines.
# Don't want to use "raw" either, because we don't want to check inside C++11
# raw strings,
raw = clean_lines.lines_without_raw_strings
line = raw[linenum]
# Before nixing comments, check if the line is blank for no good
# reason. This includes the first line after a block is opened, and
# blank lines at the end of a function (ie, right before a line like '}'
#
# Skip all the blank line checks if we are immediately inside a
# namespace body. In other words, don't issue blank line warnings
# for this block:
# namespace {
#
# }
#
# A warning about missing end of namespace comments will be issued instead.
#
# Also skip blank line checks for 'extern "C"' blocks, which are formatted
# like namespaces.
if (IsBlankLine(line) and
not nesting_state.InNamespaceBody() and
not nesting_state.InExternC()):
elided = clean_lines.elided
prev_line = elided[linenum - 1]
prevbrace = prev_line.rfind('{')
# TODO(unknown): Don't complain if line before blank line, and line after,
# both start with alnums and are indented the same amount.
# This ignores whitespace at the start of a namespace block
# because those are not usually indented.
if prevbrace != -1 and prev_line[prevbrace:].find('}') == -1:
# OK, we have a blank line at the start of a code block. Before we
# complain, we check if it is an exception to the rule: The previous
# non-empty line has the parameters of a function header that are indented
# 4 spaces (because they did not fit in a 80 column line when placed on
# the same line as the function name). We also check for the case where
# the previous line is indented 6 spaces, which may happen when the
# initializers of a constructor do not fit into a 80 column line.
exception = False
if Match(r' {6}\w', prev_line): # Initializer list?
# We are looking for the opening column of initializer list, which
# should be indented 4 spaces to cause 6 space indentation afterwards.
search_position = linenum-2
while (search_position >= 0
and Match(r' {6}\w', elided[search_position])):
search_position -= 1
exception = (search_position >= 0
and elided[search_position][:5] == ' :')
else:
# Search for the function arguments or an initializer list. We use a
# simple heuristic here: If the line is indented 4 spaces; and we have a
# closing paren, without the opening paren, followed by an opening brace
# or colon (for initializer lists) we assume that it is the last line of
# a function header. If we have a colon indented 4 spaces, it is an
# initializer list.
exception = (Match(r' {4}\w[^\(]*\)\s*(const\s*)?(\{\s*$|:)',
prev_line)
or Match(r' {4}:', prev_line))
if not exception:
error(filename, linenum, 'whitespace/blank_line', 2,
'Redundant blank line at the start of a code block '
'should be deleted.')
# Ignore blank lines at the end of a block in a long if-else
# chain, like this:
# if (condition1) {
# // Something followed by a blank line
#
# } else if (condition2) {
# // Something else
# }
if linenum + 1 < clean_lines.NumLines():
next_line = raw[linenum + 1]
if (next_line
and Match(r'\s*}', next_line)
and next_line.find('} else ') == -1):
error(filename, linenum, 'whitespace/blank_line', 3,
'Redundant blank line at the end of a code block '
'should be deleted.')
matched = Match(r'\s*(public|protected|private):', prev_line)
if matched:
error(filename, linenum, 'whitespace/blank_line', 3,
'Do not leave a blank line after "%s:"' % matched.group(1))
# Next, check comments
next_line_start = 0
if linenum + 1 < clean_lines.NumLines():
next_line = raw[linenum + 1]
next_line_start = len(next_line) - len(next_line.lstrip())
CheckComment(line, filename, linenum, next_line_start, error)
# get rid of comments and strings
line = clean_lines.elided[linenum]
# You shouldn't have spaces before your brackets, except maybe after
# 'delete []', 'return []() {};', or 'auto [abc, ...] = ...;'.
if Search(r'\w\s+\[', line) and not Search(r'(?:auto&?|delete|return)\s+\[', line):
error(filename, linenum, 'whitespace/braces', 5,
'Extra space before [')
# In range-based for, we wanted spaces before and after the colon, but
# not around "::" tokens that might appear.
if (Search(r'for *\(.*[^:]:[^: ]', line) or
Search(r'for *\(.*[^: ]:[^:]', line)):
error(filename, linenum, 'whitespace/forcolon', 2,
'Missing space around colon in range-based for loop')
def CheckOperatorSpacing(filename, clean_lines, linenum, error):
"""Checks for horizontal spacing around operators.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
# Don't try to do spacing checks for operator methods. Do this by
# replacing the troublesome characters with something else,
# preserving column position for all other characters.
#
# The replacement is done repeatedly to avoid false positives from
# operators that call operators.
while True:
match = Match(r'^(.*\boperator\b)(\S+)(\s*\(.*)$', line)
if match:
line = match.group(1) + ('_' * len(match.group(2))) + match.group(3)
else:
break
# We allow no-spaces around = within an if: "if ( (a=Foo()) == 0 )".
# Otherwise not. Note we only check for non-spaces on *both* sides;
# sometimes people put non-spaces on one side when aligning ='s among
# many lines (not that this is behavior that I approve of...)
if ((Search(r'[\w.]=', line) or
Search(r'=[\w.]', line))
and not Search(r'\b(if|while|for) ', line)
# Operators taken from [lex.operators] in C++11 standard.
and not Search(r'(>=|<=|==|!=|&=|\^=|\|=|\+=|\*=|\/=|\%=)', line)
and not Search(r'operator=', line)):
error(filename, linenum, 'whitespace/operators', 4,
'Missing spaces around =')
# It's ok not to have spaces around binary operators like + - * /, but if
# there's too little whitespace, we get concerned. It's hard to tell,
# though, so we punt on this one for now. TODO.
# You should always have whitespace around binary operators.
#
# Check <= and >= first to avoid false positives with < and >, then
# check non-include lines for spacing around < and >.
#
# If the operator is followed by a comma, assume it's be used in a
# macro context and don't do any checks. This avoids false
# positives.
#
# Note that && is not included here. This is because there are too
# many false positives due to RValue references.
match = Search(r'[^<>=!\s](==|!=|<=|>=|\|\|)[^<>=!\s,;\)]', line)
if match:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around %s' % match.group(1))
elif not Match(r'#.*include', line):
# Look for < that is not surrounded by spaces. This is only
# triggered if both sides are missing spaces, even though
# technically should should flag if at least one side is missing a
# space. This is done to avoid some false positives with shifts.
match = Match(r'^(.*[^\s<])<[^\s=<,]', line)
if match:
(_, _, end_pos) = CloseExpression(
clean_lines, linenum, len(match.group(1)))
if end_pos <= -1:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around <')
# Look for > that is not surrounded by spaces. Similar to the
# above, we only trigger if both sides are missing spaces to avoid
# false positives with shifts.
match = Match(r'^(.*[^-\s>])>[^\s=>,]', line)
if match:
(_, _, start_pos) = ReverseCloseExpression(
clean_lines, linenum, len(match.group(1)))
if start_pos <= -1:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around >')
# We allow no-spaces around << when used like this: 10<<20, but
# not otherwise (particularly, not when used as streams)
#
# We also allow operators following an opening parenthesis, since
# those tend to be macros that deal with operators.
match = Search(r'(operator|[^\s(<])(?:L|UL|LL|ULL|l|ul|ll|ull)?<<([^\s,=<])', line)
if (match and not (match.group(1).isdigit() and match.group(2).isdigit()) and
not (match.group(1) == 'operator' and match.group(2) == ';')):
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around <<')
# We allow no-spaces around >> for almost anything. This is because
# C++11 allows ">>" to close nested templates, which accounts for
# most cases when ">>" is not followed by a space.
#
# We still warn on ">>" followed by alpha character, because that is
# likely due to ">>" being used for right shifts, e.g.:
# value >> alpha
#
# When ">>" is used to close templates, the alphanumeric letter that
# follows would be part of an identifier, and there should still be
# a space separating the template type and the identifier.
# type<type<type>> alpha
match = Search(r'>>[a-zA-Z_]', line)
if match:
error(filename, linenum, 'whitespace/operators', 3,
'Missing spaces around >>')
# There shouldn't be space around unary operators
match = Search(r'(!\s|~\s|[\s]--[\s;]|[\s]\+\+[\s;])', line)
if match:
error(filename, linenum, 'whitespace/operators', 4,
'Extra space for operator %s' % match.group(1))
def CheckParenthesisSpacing(filename, clean_lines, linenum, error):
"""Checks for horizontal spacing around parentheses.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
# No spaces after an if, while, switch, or for
match = Search(r' (if\(|for\(|while\(|switch\()', line)
if match:
error(filename, linenum, 'whitespace/parens', 5,
'Missing space before ( in %s' % match.group(1))
# For if/for/while/switch, the left and right parens should be
# consistent about how many spaces are inside the parens, and
# there should either be zero or one spaces inside the parens.
# We don't want: "if ( foo)" or "if ( foo )".
# Exception: "for ( ; foo; bar)" and "for (foo; bar; )" are allowed.
match = Search(r'\b(if|for|while|switch)\s*'
r'\(([ ]*)(.).*[^ ]+([ ]*)\)\s*{\s*$',
line)
if match:
if len(match.group(2)) != len(match.group(4)):
if not (match.group(3) == ';' and
len(match.group(2)) == 1 + len(match.group(4)) or
not match.group(2) and Search(r'\bfor\s*\(.*; \)', line)):
error(filename, linenum, 'whitespace/parens', 5,
'Mismatching spaces inside () in %s' % match.group(1))
if len(match.group(2)) not in [0, 1]:
error(filename, linenum, 'whitespace/parens', 5,
'Should have zero or one spaces inside ( and ) in %s' %
match.group(1))
def CheckCommaSpacing(filename, clean_lines, linenum, error):
"""Checks for horizontal spacing near commas and semicolons.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
raw = clean_lines.lines_without_raw_strings
line = clean_lines.elided[linenum]
# You should always have a space after a comma (either as fn arg or operator)
#
# This does not apply when the non-space character following the
# comma is another comma, since the only time when that happens is
# for empty macro arguments.
#
# We run this check in two passes: first pass on elided lines to
# verify that lines contain missing whitespaces, second pass on raw
# lines to confirm that those missing whitespaces are not due to
# elided comments.
if (Search(r',[^,\s]', ReplaceAll(r'\boperator\s*,\s*\(', 'F(', line)) and
Search(r',[^,\s]', raw[linenum])):
error(filename, linenum, 'whitespace/comma', 3,
'Missing space after ,')
# You should always have a space after a semicolon
# except for few corner cases
# TODO(unknown): clarify if 'if (1) { return 1;}' is requires one more
# space after ;
if Search(r';[^\s};\\)/]', line):
error(filename, linenum, 'whitespace/semicolon', 3,
'Missing space after ;')
def _IsType(clean_lines, nesting_state, expr):
"""Check if expression looks like a type name, returns true if so.
Args:
clean_lines: A CleansedLines instance containing the file.
nesting_state: A NestingState instance which maintains information about
the current stack of nested blocks being parsed.
expr: The expression to check.
Returns:
True, if token looks like a type.
"""
# Keep only the last token in the expression
last_word = Match(r'^.*(\b\S+)$', expr)
if last_word:
token = last_word.group(1)
else:
token = expr
# Match native types and stdint types
if _TYPES.match(token):
return True
# Try a bit harder to match templated types. Walk up the nesting
# stack until we find something that resembles a typename
# declaration for what we are looking for.
typename_pattern = (r'\b(?:typename|class|struct)\s+' + re.escape(token) +
r'\b')
block_index = len(nesting_state.stack) - 1
while block_index >= 0:
if isinstance(nesting_state.stack[block_index], _NamespaceInfo):
return False
# Found where the opening brace is. We want to scan from this
# line up to the beginning of the function, minus a few lines.
# template <typename Type1, // stop scanning here
# ...>
# class C
# : public ... { // start scanning here
last_line = nesting_state.stack[block_index].starting_linenum
next_block_start = 0
if block_index > 0:
next_block_start = nesting_state.stack[block_index - 1].starting_linenum
first_line = last_line
while first_line >= next_block_start:
if clean_lines.elided[first_line].find('template') >= 0:
break
first_line -= 1
if first_line < next_block_start:
# Didn't find any "template" keyword before reaching the next block,
# there are probably no template things to check for this block
block_index -= 1
continue
# Look for typename in the specified range
for i in xrange(first_line, last_line + 1, 1):
if Search(typename_pattern, clean_lines.elided[i]):
return True
block_index -= 1
return False
def CheckBracesSpacing(filename, clean_lines, linenum, nesting_state, error):
"""Checks for horizontal spacing near commas.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
nesting_state: A NestingState instance which maintains information about
the current stack of nested blocks being parsed.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
# Except after an opening paren, or after another opening brace (in case of
# an initializer list, for instance), you should have spaces before your
# braces when they are delimiting blocks, classes, namespaces etc.
# And since you should never have braces at the beginning of a line,
# this is an easy test. Except that braces used for initialization don't
# follow the same rule; we often don't want spaces before those.
match = Match(r'^(.*[^ ({>]){', line)
if match:
# Try a bit harder to check for brace initialization. This
# happens in one of the following forms:
# Constructor() : initializer_list_{} { ... }
# Constructor{}.MemberFunction()
# Type variable{};
# FunctionCall(type{}, ...);
# LastArgument(..., type{});
# LOG(INFO) << type{} << " ...";
# map_of_type[{...}] = ...;
# ternary = expr ? new type{} : nullptr;
# OuterTemplate<InnerTemplateConstructor<Type>{}>
#
# We check for the character following the closing brace, and
# silence the warning if it's one of those listed above, i.e.
# "{.;,)<>]:".
#
# To account for nested initializer list, we allow any number of
# closing braces up to "{;,)<". We can't simply silence the
# warning on first sight of closing brace, because that would
# cause false negatives for things that are not initializer lists.
# Silence this: But not this:
# Outer{ if (...) {
# Inner{...} if (...){ // Missing space before {
# }; }
#
# There is a false negative with this approach if people inserted
# spurious semicolons, e.g. "if (cond){};", but we will catch the
# spurious semicolon with a separate check.
leading_text = match.group(1)
(endline, endlinenum, endpos) = CloseExpression(
clean_lines, linenum, len(match.group(1)))
trailing_text = ''
if endpos > -1:
trailing_text = endline[endpos:]
for offset in xrange(endlinenum + 1,
min(endlinenum + 3, clean_lines.NumLines() - 1)):
trailing_text += clean_lines.elided[offset]
# We also suppress warnings for `uint64_t{expression}` etc., as the style
# guide recommends brace initialization for integral types to avoid
# overflow/truncation.
if (not Match(r'^[\s}]*[{.;,)<>\]:]', trailing_text)
and not _IsType(clean_lines, nesting_state, leading_text)):
error(filename, linenum, 'whitespace/braces', 5,
'Missing space before {')
# Make sure '} else {' has spaces.
if Search(r'}else', line):
error(filename, linenum, 'whitespace/braces', 5,
'Missing space before else')
# You shouldn't have a space before a semicolon at the end of the line.
# There's a special case for "for" since the style guide allows space before
# the semicolon there.
if Search(r':\s*;\s*$', line):
error(filename, linenum, 'whitespace/semicolon', 5,
'Semicolon defining empty statement. Use {} instead.')
elif Search(r'^\s*;\s*$', line):
error(filename, linenum, 'whitespace/semicolon', 5,
'Line contains only semicolon. If this should be an empty statement, '
'use {} instead.')
elif (Search(r'\s+;\s*$', line) and
not Search(r'\bfor\b', line)):
error(filename, linenum, 'whitespace/semicolon', 5,
'Extra space before last semicolon. If this should be an empty '
'statement, use {} instead.')
def IsDecltype(clean_lines, linenum, column):
"""Check if the token ending on (linenum, column) is decltype().
Args:
clean_lines: A CleansedLines instance containing the file.
linenum: the number of the line to check.
column: end column of the token to check.
Returns:
True if this token is decltype() expression, False otherwise.
"""
(text, _, start_col) = ReverseCloseExpression(clean_lines, linenum, column)
if start_col < 0:
return False
if Search(r'\bdecltype\s*$', text[0:start_col]):
return True
return False
def CheckSectionSpacing(filename, clean_lines, class_info, linenum, error):
"""Checks for additional blank line issues related to sections.
Currently the only thing checked here is blank line before protected/private.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
class_info: A _ClassInfo objects.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
# Skip checks if the class is small, where small means 25 lines or less.
# 25 lines seems like a good cutoff since that's the usual height of
# terminals, and any class that can't fit in one screen can't really
# be considered "small".
#
# Also skip checks if we are on the first line. This accounts for
# classes that look like
# class Foo { public: ... };
#
# If we didn't find the end of the class, last_line would be zero,
# and the check will be skipped by the first condition.
if (class_info.last_line - class_info.starting_linenum <= 24 or
linenum <= class_info.starting_linenum):
return
matched = Match(r'\s*(public|protected|private):', clean_lines.lines[linenum])
if matched:
# Issue warning if the line before public/protected/private was
# not a blank line, but don't do this if the previous line contains
# "class" or "struct". This can happen two ways:
# - We are at the beginning of the class.
# - We are forward-declaring an inner class that is semantically
# private, but needed to be public for implementation reasons.
# Also ignores cases where the previous line ends with a backslash as can be
# common when defining classes in C macros.
prev_line = clean_lines.lines[linenum - 1]
if (not IsBlankLine(prev_line) and
not Search(r'\b(class|struct)\b', prev_line) and
not Search(r'\\$', prev_line)):
# Try a bit harder to find the beginning of the class. This is to
# account for multi-line base-specifier lists, e.g.:
# class Derived
# : public Base {
end_class_head = class_info.starting_linenum
for i in range(class_info.starting_linenum, linenum):
if Search(r'\{\s*$', clean_lines.lines[i]):
end_class_head = i
break
if end_class_head < linenum - 1:
error(filename, linenum, 'whitespace/blank_line', 3,
'"%s:" should be preceded by a blank line' % matched.group(1))
def GetPreviousNonBlankLine(clean_lines, linenum):
"""Return the most recent non-blank line and its line number.
Args:
clean_lines: A CleansedLines instance containing the file contents.
linenum: The number of the line to check.
Returns:
A tuple with two elements. The first element is the contents of the last
non-blank line before the current line, or the empty string if this is the
first non-blank line. The second is the line number of that line, or -1
if this is the first non-blank line.
"""
prevlinenum = linenum - 1
while prevlinenum >= 0:
prevline = clean_lines.elided[prevlinenum]
if not IsBlankLine(prevline): # if not a blank line...
return (prevline, prevlinenum)
prevlinenum -= 1
return ('', -1)
def CheckBraces(filename, clean_lines, linenum, error):
"""Looks for misplaced braces (e.g. at the end of line).
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum] # get rid of comments and strings
if Match(r'\s*{\s*$', line):
# We allow an open brace to start a line in the case where someone is using
# braces in a block to explicitly create a new scope, which is commonly used
# to control the lifetime of stack-allocated variables. Braces are also
# used for brace initializers inside function calls. We don't detect this
# perfectly: we just don't complain if the last non-whitespace character on
# the previous non-blank line is ',', ';', ':', '(', '{', or '}', or if the
# previous line starts a preprocessor block. We also allow a brace on the
# following line if it is part of an array initialization and would not fit
# within the 80 character limit of the preceding line.
prevline = GetPreviousNonBlankLine(clean_lines, linenum)[0]
if (not Search(r'[,;:}{(]\s*$', prevline) and
not Match(r'\s*#', prevline) and
not (GetLineWidth(prevline) > _line_length - 2 and '[]' in prevline)):
error(filename, linenum, 'whitespace/braces', 4,
'{ should almost always be at the end of the previous line')
# An else clause should be on the same line as the preceding closing brace.
if Match(r'\s*else\b\s*(?:if\b|\{|$)', line):
prevline = GetPreviousNonBlankLine(clean_lines, linenum)[0]
if Match(r'\s*}\s*$', prevline):
error(filename, linenum, 'whitespace/newline', 4,
'An else should appear on the same line as the preceding }')
# If braces come on one side of an else, they should be on both.
# However, we have to worry about "else if" that spans multiple lines!
if Search(r'else if\s*\(', line): # could be multi-line if
brace_on_left = bool(Search(r'}\s*else if\s*\(', line))
# find the ( after the if
pos = line.find('else if')
pos = line.find('(', pos)
if pos > 0:
(endline, _, endpos) = CloseExpression(clean_lines, linenum, pos)
brace_on_right = endline[endpos:].find('{') != -1
if brace_on_left != brace_on_right: # must be brace after if
error(filename, linenum, 'readability/braces', 5,
'If an else has a brace on one side, it should have it on both')
elif Search(r'}\s*else[^{]*$', line) or Match(r'[^}]*else\s*{', line):
error(filename, linenum, 'readability/braces', 5,
'If an else has a brace on one side, it should have it on both')
# Likewise, an else should never have the else clause on the same line
if Search(r'\belse [^\s{]', line) and not Search(r'\belse if\b', line):
error(filename, linenum, 'whitespace/newline', 4,
'Else clause should never be on same line as else (use 2 lines)')
# In the same way, a do/while should never be on one line
if Match(r'\s*do [^\s{]', line):
error(filename, linenum, 'whitespace/newline', 4,
'do/while clauses should not be on a single line')
# Check single-line if/else bodies. The style guide says 'curly braces are not
# required for single-line statements'. We additionally allow multi-line,
# single statements, but we reject anything with more than one semicolon in
# it. This means that the first semicolon after the if should be at the end of
# its line, and the line after that should have an indent level equal to or
# lower than the if. We also check for ambiguous if/else nesting without
# braces.
if_else_match = Search(r'\b(if\s*\(|else\b)', line)
if if_else_match and not Match(r'\s*#', line):
if_indent = GetIndentLevel(line)
endline, endlinenum, endpos = line, linenum, if_else_match.end()
if_match = Search(r'\bif\s*\(', line)
if if_match:
# This could be a multiline if condition, so find the end first.
pos = if_match.end() - 1
(endline, endlinenum, endpos) = CloseExpression(clean_lines, linenum, pos)
# Check for an opening brace, either directly after the if or on the next
# line. If found, this isn't a single-statement conditional.
if (not Match(r'\s*{', endline[endpos:])
and not (Match(r'\s*$', endline[endpos:])
and endlinenum < (len(clean_lines.elided) - 1)
and Match(r'\s*{', clean_lines.elided[endlinenum + 1]))):
while (endlinenum < len(clean_lines.elided)
and ';' not in clean_lines.elided[endlinenum][endpos:]):
endlinenum += 1
endpos = 0
if endlinenum < len(clean_lines.elided):
endline = clean_lines.elided[endlinenum]
# We allow a mix of whitespace and closing braces (e.g. for one-liner
# methods) and a single \ after the semicolon (for macros)
endpos = endline.find(';')
if not Match(r';[\s}]*(\\?)$', endline[endpos:]):
# Semicolon isn't the last character, there's something trailing.
# Output a warning if the semicolon is not contained inside
# a lambda expression.
if not Match(r'^[^{};]*\[[^\[\]]*\][^{}]*\{[^{}]*\}\s*\)*[;,]\s*$',
endline):
error(filename, linenum, 'readability/braces', 4,
'If/else bodies with multiple statements require braces')
elif endlinenum < len(clean_lines.elided) - 1:
# Make sure the next line is dedented
next_line = clean_lines.elided[endlinenum + 1]
next_indent = GetIndentLevel(next_line)
# With ambiguous nested if statements, this will error out on the
# if that *doesn't* match the else, regardless of whether it's the
# inner one or outer one.
if (if_match and Match(r'\s*else\b', next_line)
and next_indent != if_indent):
error(filename, linenum, 'readability/braces', 4,
'Else clause should be indented at the same level as if. '
'Ambiguous nested if/else chains require braces.')
elif next_indent > if_indent:
error(filename, linenum, 'readability/braces', 4,
'If/else bodies with multiple statements require braces')
def CheckTrailingSemicolon(filename, clean_lines, linenum, error):
"""Looks for redundant trailing semicolon.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
line = clean_lines.elided[linenum]
# Block bodies should not be followed by a semicolon. Due to C++11
# brace initialization, there are more places where semicolons are
# required than not, so we explicitly list the allowed rules rather
# than listing the disallowed ones. These are the places where "};"
# should be replaced by just "}":
# 1. Some flavor of block following closing parenthesis:
# for (;;) {};
# while (...) {};
# switch (...) {};
# Function(...) {};
# if (...) {};
# if (...) else if (...) {};
#
# 2. else block:
# if (...) else {};
#
# 3. const member function:
# Function(...) const {};
#
# 4. Block following some statement:
# x = 42;
# {};
#
# 5. Block at the beginning of a function:
# Function(...) {
# {};
# }
#
# Note that naively checking for the preceding "{" will also match
# braces inside multi-dimensional arrays, but this is fine since
# that expression will not contain semicolons.
#
# 6. Block following another block:
# while (true) {}
# {};
#
# 7. End of namespaces:
# namespace {};
#
# These semicolons seems far more common than other kinds of
# redundant semicolons, possibly due to people converting classes
# to namespaces. For now we do not warn for this case.
#
# Try matching case 1 first.
match = Match(r'^(.*\)\s*)\{', line)
if match:
# Matched closing parenthesis (case 1). Check the token before the
# matching opening parenthesis, and don't warn if it looks like a
# macro. This avoids these false positives:
# - macro that defines a base class
# - multi-line macro that defines a base class
# - macro that defines the whole class-head
#
# But we still issue warnings for macros that we know are safe to
# warn, specifically:
# - TEST, TEST_F, TEST_P, MATCHER, MATCHER_P
# - TYPED_TEST
# - INTERFACE_DEF
# - EXCLUSIVE_LOCKS_REQUIRED, SHARED_LOCKS_REQUIRED, LOCKS_EXCLUDED:
#
# We implement a list of safe macros instead of a list of
# unsafe macros, even though the latter appears less frequently in
# google code and would have been easier to implement. This is because
# the downside for getting the allowed checks wrong means some extra
# semicolons, while the downside for getting disallowed checks wrong
# would result in compile errors.
#
# In addition to macros, we also don't want to warn on
# - Compound literals
# - Lambdas
# - alignas specifier with anonymous structs
# - decltype
closing_brace_pos = match.group(1).rfind(')')
opening_parenthesis = ReverseCloseExpression(
clean_lines, linenum, closing_brace_pos)
if opening_parenthesis[2] > -1:
line_prefix = opening_parenthesis[0][0:opening_parenthesis[2]]
macro = Search(r'\b([A-Z_][A-Z0-9_]*)\s*$', line_prefix)
func = Match(r'^(.*\])\s*$', line_prefix)
if ((macro and
macro.group(1) not in (
'TEST', 'TEST_F', 'MATCHER', 'MATCHER_P', 'TYPED_TEST',
'EXCLUSIVE_LOCKS_REQUIRED', 'SHARED_LOCKS_REQUIRED',
'LOCKS_EXCLUDED', 'INTERFACE_DEF')) or
(func and not Search(r'\boperator\s*\[\s*\]', func.group(1))) or
Search(r'\b(?:struct|union)\s+alignas\s*$', line_prefix) or
Search(r'\bdecltype$', line_prefix) or
Search(r'\s+=\s*$', line_prefix)):
match = None
if (match and
opening_parenthesis[1] > 1 and
Search(r'\]\s*$', clean_lines.elided[opening_parenthesis[1] - 1])):
# Multi-line lambda-expression
match = None
else:
# Try matching cases 2-3.
match = Match(r'^(.*(?:else|\)\s*const)\s*)\{', line)
if not match:
# Try matching cases 4-6. These are always matched on separate lines.
#
# Note that we can't simply concatenate the previous line to the
# current line and do a single match, otherwise we may output
# duplicate warnings for the blank line case:
# if (cond) {
# // blank line
# }
prevline = GetPreviousNonBlankLine(clean_lines, linenum)[0]
if prevline and Search(r'[;{}]\s*$', prevline):
match = Match(r'^(\s*)\{', line)
# Check matching closing brace
if match:
(endline, endlinenum, endpos) = CloseExpression(
clean_lines, linenum, len(match.group(1)))
if endpos > -1 and Match(r'^\s*;', endline[endpos:]):
# Current {} pair is eligible for semicolon check, and we have found
# the redundant semicolon, output warning here.
#
# Note: because we are scanning forward for opening braces, and
# outputting warnings for the matching closing brace, if there are
# nested blocks with trailing semicolons, we will get the error
# messages in reversed order.
# We need to check the line forward for NOLINT
raw_lines = clean_lines.raw_lines
ParseNolintSuppressions(filename, raw_lines[endlinenum-1], endlinenum-1,
error)
ParseNolintSuppressions(filename, raw_lines[endlinenum], endlinenum,
error)
error(filename, endlinenum, 'readability/braces', 4,
"You don't need a ; after a }")
def CheckEmptyBlockBody(filename, clean_lines, linenum, error):
"""Look for empty loop/conditional body with only a single semicolon.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
# Search for loop keywords at the beginning of the line. Because only
# whitespaces are allowed before the keywords, this will also ignore most
# do-while-loops, since those lines should start with closing brace.
#
# We also check "if" blocks here, since an empty conditional block
# is likely an error.
line = clean_lines.elided[linenum]
matched = Match(r'\s*(for|while|if)\s*\(', line)
if matched:
# Find the end of the conditional expression.
(end_line, end_linenum, end_pos) = CloseExpression(
clean_lines, linenum, line.find('('))
# Output warning if what follows the condition expression is a semicolon.
# No warning for all other cases, including whitespace or newline, since we
# have a separate check for semicolons preceded by whitespace.
if end_pos >= 0 and Match(r';', end_line[end_pos:]):
if matched.group(1) == 'if':
error(filename, end_linenum, 'whitespace/empty_conditional_body', 5,
'Empty conditional bodies should use {}')
else:
error(filename, end_linenum, 'whitespace/empty_loop_body', 5,
'Empty loop bodies should use {} or continue')
# Check for if statements that have completely empty bodies (no comments)
# and no else clauses.
if end_pos >= 0 and matched.group(1) == 'if':
# Find the position of the opening { for the if statement.
# Return without logging an error if it has no brackets.
opening_linenum = end_linenum
opening_line_fragment = end_line[end_pos:]
# Loop until EOF or find anything that's not whitespace or opening {.
while not Search(r'^\s*\{', opening_line_fragment):
if Search(r'^(?!\s*$)', opening_line_fragment):
# Conditional has no brackets.
return
opening_linenum += 1
if opening_linenum == len(clean_lines.elided):
# Couldn't find conditional's opening { or any code before EOF.
return
opening_line_fragment = clean_lines.elided[opening_linenum]
# Set opening_line (opening_line_fragment may not be entire opening line).
opening_line = clean_lines.elided[opening_linenum]
# Find the position of the closing }.
opening_pos = opening_line_fragment.find('{')
if opening_linenum == end_linenum:
# We need to make opening_pos relative to the start of the entire line.
opening_pos += end_pos
(closing_line, closing_linenum, closing_pos) = CloseExpression(
clean_lines, opening_linenum, opening_pos)
if closing_pos < 0:
return
# Now construct the body of the conditional. This consists of the portion
# of the opening line after the {, all lines until the closing line,
# and the portion of the closing line before the }.
if (clean_lines.raw_lines[opening_linenum] !=
CleanseComments(clean_lines.raw_lines[opening_linenum])):
# Opening line ends with a comment, so conditional isn't empty.
return
if closing_linenum > opening_linenum:
# Opening line after the {. Ignore comments here since we checked above.
body = list(opening_line[opening_pos+1:])
# All lines until closing line, excluding closing line, with comments.
body.extend(clean_lines.raw_lines[opening_linenum+1:closing_linenum])
# Closing line before the }. Won't (and can't) have comments.
body.append(clean_lines.elided[closing_linenum][:closing_pos-1])
body = '\n'.join(body)
else:
# If statement has brackets and fits on a single line.
body = opening_line[opening_pos+1:closing_pos-1]
# Check if the body is empty
if not _EMPTY_CONDITIONAL_BODY_PATTERN.search(body):
return
# The body is empty. Now make sure there's not an else clause.
current_linenum = closing_linenum
current_line_fragment = closing_line[closing_pos:]
# Loop until EOF or find anything that's not whitespace or else clause.
while Search(r'^\s*$|^(?=\s*else)', current_line_fragment):
if Search(r'^(?=\s*else)', current_line_fragment):
# Found an else clause, so don't log an error.
return
current_linenum += 1
if current_linenum == len(clean_lines.elided):
break
current_line_fragment = clean_lines.elided[current_linenum]
# The body is empty and there's no else clause until EOF or other code.
error(filename, end_linenum, 'whitespace/empty_if_body', 4,
('If statement had no body and no else clause'))
def FindCheckMacro(line):
"""Find a replaceable CHECK-like macro.
Args:
line: line to search on.
Returns:
(macro name, start position), or (None, -1) if no replaceable
macro is found.
"""
for macro in _CHECK_MACROS:
i = line.find(macro)
if i >= 0:
# Find opening parenthesis. Do a regular expression match here
# to make sure that we are matching the expected CHECK macro, as
# opposed to some other macro that happens to contain the CHECK
# substring.
matched = Match(r'^(.*\b' + macro + r'\s*)\(', line)
if not matched:
continue
return (macro, len(matched.group(1)))
return (None, -1)
def CheckCheck(filename, clean_lines, linenum, error):
"""Checks the use of CHECK and EXPECT macros.
Args:
filename: The name of the current file.
clean_lines: A CleansedLines instance containing the file.
linenum: The number of the line to check.
error: The function to call with any errors found.
"""
# Decide the set of replacement macros that should be suggested
lines = clean_lines.elided
(check_macro, start_pos) = FindCheckMacro(lines[linenum])
if not check_macro:
return
# Find end of the boolean expression by matching parentheses
(last_line, end_line, end_pos) = CloseExpression(
clean_lines, linenum, start_pos)
if end_pos < 0:
return
# If the check macro is followed by something other than a
# semicolon, assume users will log their own custom error messages
# and don't suggest any replacements.
if not Match(r'\s*;', last_line[end_pos:]):
return
if linenum == end_line:
expression = lines[linenum][start_pos + 1:end_pos - 1]
else:
expression = lines[linenum][start_pos + 1:]
for i in xrange(linenum + 1, end_line):
expression += lines[i]
expression += last_line[0:end_pos - 1]
# Parse expression so that we can take parentheses into account.
# This avoids false positives for inputs like "CHECK((a < 4) == b)",
# which is not replaceable by CHECK_LE.
lhs = ''
rhs = ''
operator = None
while expression:
matched = Match(r'^\s*(<<|<<=|>>|>>=|->\*|->|&&|\|\||'
r'==|!=|>=|>|<=|<|\()(.*)$', expression)
if matched:
token = matched.group(1)
if token == '(':
# Parenthesized operand
expression = matched.group(2)
(end, _) = FindEndOfExpressionInLine(expression, 0, ['('])
if end < 0:
return # Unmatched parenthesis
lhs += '(' + expression[0:end]
expression = expression[end:]
elif token in ('&&', '||'):
# Logical and/or operators. This means the expression
# contains more than one term, for example: