cpplint
cpplint documentation
- Version in MegaLinter: 1.6.1
- Visit Official Web Site
- See Index of problems detected by cpplint
Configuration in MegaLinter
- Enable cpplint by adding
CPP_CPPLINT
in ENABLE_LINTERS variable - Disable cpplint by adding
CPP_CPPLINT
in DISABLE_LINTERS variable
Variable | Description | Default value |
---|---|---|
CPP_CPPLINT_ARGUMENTS | User custom arguments to add in linter CLI call Ex: -s --foo "bar" |
|
CPP_CPPLINT_FILTER_REGEX_INCLUDE | Custom regex including filter Ex: (src\|lib) |
Include every file |
CPP_CPPLINT_FILTER_REGEX_EXCLUDE | Custom regex excluding filter Ex: (test\|examples) |
Exclude no file |
CPP_CPPLINT_CLI_LINT_MODE | Override default CLI lint mode - file : Calls the linter for each file- list_of_files : Call the linter with the list of files as argument- project : Call the linter from the root of the project |
list_of_files |
CPP_CPPLINT_FILE_EXTENSIONS | Allowed file extensions. "*" matches any extension, "" matches empty extension. Empty list excludes all filesEx: [".py", ""] |
[".cpp", ".h", ".cc", ".hpp", ".cxx", ".cu", ".hxx", ".c++", ".hh", ".h++", ".cuh"] |
CPP_CPPLINT_FILE_NAMES_REGEX | File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: ["Dockerfile(-.+)?", "Jenkinsfile"] |
Include every file |
CPP_CPPLINT_PRE_COMMANDS | List of bash commands to run before the linter | None |
CPP_CPPLINT_POST_COMMANDS | List of bash commands to run after the linter | None |
CPP_CPPLINT_UNSECURED_ENV_VARIABLES | List of env variables explicitly not filtered before calling CPP_CPPLINT and its pre/post commands | None |
CPP_CPPLINT_DISABLE_ERRORS | Run linter but consider errors as warnings | false |
CPP_CPPLINT_DISABLE_ERRORS_IF_LESS_THAN | Maximum number of errors allowed | 0 |
CPP_CPPLINT_CLI_EXECUTABLE | Override CLI executable | ['cpplint'] |
MegaLinter Flavours
This linter is available in the following flavours
Flavor | Description | Embedded linters | Info | |
---|---|---|---|---|
all | Default MegaLinter Flavor | 113 | ||
cupcake | MegaLinter for the most commonly used languages | 81 | ||
dotnet | Optimized for C, C++, C# or VB based projects | 59 |
Behind the scenes
How are identified applicable files
- File extensions:
.cpp
,.h
,.cc
,.hpp
,.cxx
,.cu
,.hxx
,.c++
,.hh
,.h++
,.cuh
How the linting is performed
- cpplint is called once with the list of files as arguments (
list_of_files
CLI lint mode)
Example calls
cpplint myfile.cpp
Help content
Syntax: cpplint.py [--verbose=#] [--output=emacs|eclipse|vs7|junit|sed|gsed]
[--filter=-x,+y,...]
[--counting=total|toplevel|detailed] [--root=subdir]
[--repository=path]
[--linelength=digits] [--headers=x,y,...]
[--recursive]
[--exclude=path]
[--extensions=hpp,cpp,...]
[--includeorder=default|standardcfirst]
[--quiet]
[--version]
<file> [file] ...
Style checker for C/C++ source files.
This is a fork of the Google style checker with minor extensions.
The style guidelines this tries to follow are those in
https://google.github.io/styleguide/cppguide.html
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 ['c', 'c++', 'cc', 'cpp', 'cu', 'cuh', 'cxx', 'h', 'h++', 'hh', 'hpp', 'hxx'].
Other file types will be ignored.
Change the extensions with the --extensions flag.
Flags:
output=emacs|eclipse|vs7|junit|sed|gsed
By default, the output is formatted to ease emacs parsing. Visual Studio
compatible output (vs7) may also be used. Further support exists for
eclipse (eclipse), and JUnit (junit). XML parsers such as those used
in Jenkins and Bamboo may also be used.
The sed format outputs sed commands that should fix some of the errors.
Note that this requires gnu sed. If that is installed as gsed on your
system (common e.g. on macOS with homebrew) you can use the gsed output
format. Sed commands are written to stdout, not stderr, so you should be
able to pipe output straight to a shell to run the fixes.
verbose=#
Specify a number 0-5 to restrict errors to certain verbosity levels.
Errors with lower verbosity levels have lower confidence and are more
likely to be false positives.
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" 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'.
repository=path
The top level directory of the repository, used to derive the header
guard CPP variable. By default, this is determined by searching for a
path that contains .git, .hg, or .svn. When this flag is specified, the
given path is used instead. This option allows the header guard CPP
variable to remain consistent even if members of a team have different
repository root directories (such as when checking out a subdirectory
with SVN). In addition, users of non-mainstream version control systems
can use this flag to ensure readable header guard CPP variables.
Examples:
Assuming that Alice checks out ProjectName and Bob checks out
ProjectName/trunk and trunk contains src/chrome/ui/browser.h, then
with no --repository flag, the header guard CPP variable will be:
Alice => TRUNK_SRC_CHROME_BROWSER_UI_BROWSER_H_
Bob => SRC_CHROME_BROWSER_UI_BROWSER_H_
If Alice uses the --repository=trunk flag and Bob omits the flag or
uses --repository=. then the header guard CPP variable will be:
Alice => SRC_CHROME_BROWSER_UI_BROWSER_H_
Bob => SRC_CHROME_BROWSER_UI_BROWSER_H_
root=subdir
The root directory used for deriving header guard CPP variable.
This directory is relative to the top level directory of the repository
which by default is determined by searching for a directory that contains
.git, .hg, or .svn but can also be controlled with the --repository flag.
If the specified directory does not exist, this flag is ignored.
Examples:
Assuming that src is the top level directory of the repository (and
cwd=top/src), the header guard CPP variables for
src/chrome/browser/ui/browser.h are:
No flag => CHROME_BROWSER_UI_BROWSER_H_
--root=chrome => BROWSER_UI_BROWSER_H_
--root=chrome/browser => UI_BROWSER_H_
--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
recursive
Search for files to lint recursively. Each directory given in the list
of files to be linted is replaced by all files that descend from that
directory. Files with extensions not in the valid extensions list are
excluded.
exclude=path
Exclude the given path from the list of files to be linted. Relative
paths are evaluated relative to the current directory and shell globbing
is performed. This flag can be provided multiple times to exclude
multiple files.
Examples:
--exclude=one.cc
--exclude=src/*.cc
--exclude=src/*.cc --exclude=test/*.cc
extensions=extension,extension,...
The allowed file extensions that cpplint will check
Examples:
--extensions=c,c++,cc,cpp,cu,cuh,cxx,h,h++,hh,hpp,hxx
includeorder=default|standardcfirst
For the build/include_order rule, the default is to blindly assume angle
bracket includes with file extension are c-system-headers (default),
even knowing this will have false classifications.
The default is established at google.
standardcfirst means to instead use an allow-list of known c headers and
treat all others as separate group of "other system headers". The C headers
included are those of the C-standard lib and closely related ones.
headers=x,y,...
The header extensions that cpplint will treat as .h in checks. Values are
automatically added to --extensions list.
(by default, only files with extensions ['cuh', 'h', 'h++', 'hh', 'hpp', 'hxx'] will be assumed to be headers)
Examples:
--headers=cuh,h,h++,hh,hpp,hxx
--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 the linter.
"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.
Installation on mega-linter Docker image
- PIP packages (Python):