Supported Languages

This document lists all programming and markup languages which Flycheck supports.

Note

Extensions may provide support for additional languages or add deeper integration with existing languages.

Take a look at the list of extensions to see what the community can offer to you.

Each language has one or more syntax checkers whose names follow a convention of language-tool. All syntax checkers are listed in the order they would be applied to a buffer, with all available options. For more information about a syntax checker open Emacs and use flycheck-describe-checker to view the docstring of the syntax checker. Likewise, you may use describe-variable to read the complete docstring of any option.

Ada

ada-gnat

Check ADA syntax and types with GNAT.

defcustom flycheck-gnat-args

A list of additional options.

defcustom flycheck-gnat-include-path

A list of include directories. Relative paths are relative to the path of the buffer being checked.

defcustom flycheck-gnat-language-standard

The language standard to use as string.

defcustom flycheck-gnat-warnings

A list of additional warnings to enable. Each item is the name of a warning category to enable.

AsciiDoc

asciidoctor

Check AsciiDoc with the default Asciidoctor backend.

asciidoc

Check AsciiDoc with the standard AsciiDoc processor.

C/C++

Flycheck checks C and C++ with either c/c++-clang or c/c++-gcc, and then with c/c++-cppcheck.

c/c++-clang
c/c++-gcc

Check C/C++ for syntax and type errors with Clang or GCC respectively.

Note

c/c++-gcc requires GCC 4.4 or newer.

defcustom flycheck-clang-args
defcustom flycheck-gcc-args

A list of additional arguments for c/c++-clang and c/c++-gcc respectively.

defcustom flycheck-clang-blocks

Whether to enable blocks in c/c++-clang.

defcustom flycheck-clang-definitions
defcustom flycheck-gcc-definitions

A list of additional preprocessor definitions for c/c++-clang and c/c++-gcc respectively.

defcustom flycheck-clang-include-path
defcustom flycheck-gcc-include-path

A list of include directories for c/c++-clang and c/c++-gcc respectively, relative to the file being checked.

defcustom flycheck-clang-includes
defcustom flycheck-gcc-includes

A list of additional include files for c/c++-clang and c/c++-gcc respectively, relative to the file being checked.

defcustom flycheck-clang-language-standard
defcustom flycheck-gcc-language-standard

The language standard to use in c/c++-clang and c/c++-gcc respectively as string, via the -std option.

defcustom flycheck-clang-ms-extensions

Whether to enable Microsoft extensions to C/C++ in c/c++-clang.

defcustom flycheck-clang-no-exceptions
defcustom flycheck-gcc-no-exceptions

Whether to disable exceptions in c/c++-clang and c/c++-gcc respectively.

defcustom flycheck-clang-no-rtti
defcustom flycheck-gcc-no-rtti

Whether to disable RTTI in c/c++-clang and c/c++-gcc respectively, via -fno-rtti.

defcustom flycheck-clang-standard-library

The name of the standard library to use for c/c++-clang, as string.

defcustom flycheck-gcc-openmp

Whether to enable OpenMP in c/c++-gcc.

defcustom flycheck-clang-pedantic
defcustom flycheck-gcc-pedantic

Whether to warn about language extensions in c/c++-clang and c/c++-gcc respectively.

defcustom flycheck-clang-pedantic-errors
defcustom flycheck-gcc-pedantic-errors

Whether to error on language extensions in c/c++-clang and c/c++-gcc respectively.

defcustom flycheck-clang-warnings
defcustom flycheck-gcc-warnings

A list of additional warnings to enable in c/c++-clang and c/c++-gcc respectively. Each item is the name of a warning or warning category for -W.

c/c++-cppcheck

Check C/C++ for semantic and stylistic issues with cppcheck.

defcustom flycheck-cppcheck-checks

A list of enabled checks. Each item is the name of a check for the --enable option.

defcustom flycheck-cppcheck-inconclusive

Whether to enable inconclusive checks. These checks may yield more false positives than normal checks.

Note

This option requires cppcheck 1.54 or newer.

defcustom flycheck-cppcheck-include-path

A list of include directories. Relative paths are relative to the file being checked.

defcustom flycheck-cppcheck-standards

The C, C++ and/or POSIX standards to use via one or more --std= arguments.

defcustom flycheck-cppcheck-suppressions

The cppcheck suppressions list to use via one or more --suppress= arguments.

CFEngine

cfengine

Check syntax with CFEngine.

Chef

chef-foodcritic

Check style in Chef recipes with foodcritic.

defcustom flycheck-foodcritic-tags

A list of tags to select.

Coffeescript

Flycheck checks Coffeescript syntax with coffee and then lints with coffee-coffeelint.

coffee

Check syntax with the Coffeescript compiler.

coffee-coffeelint

Lint with Coffeelint.

defcustom flycheck-coffeelintrc

Configuration file for this syntax checker. See Configuration files.

Coq

coq

Check and proof with the standard Coq compiler.

CSS

css-csslint

Check syntax and style with CSSLint.

css-stylelint

Syntax-check and lint CSS with stylelint.

defcustom flycheck-stylelintrc

Configuration file for this syntax checker. See Configuration files.

defcustom flycheck-stylelint-quiet

Whether to run stylelint in quiet mode via --quiet.

D

d-dmd

Check syntax and types with (DMD).

Note

This syntax checker requires DMD 2.066 or newer.

defcustom flycheck-dmd-include-path

A list of include directories.

defcustom flycheck-dmd-args

A list of additional arguments.

See also

flycheck-d-unittest
Flycheck extension which provides a syntax checker to run D unittests on the fly and report the results with Flycheck.

Dockerfile

dockerfile-hadolint

Check syntax and code style with hadolint

Elixir

elixir-dogma

Check syntax and code style with Dogma.

Emacs Lisp

Flycheck checks Emacs Lisp with emacs-lisp and then with emacs-lisp-checkdoc.

emacs-lisp

Check syntax with the built-in byte compiler.

defcustom flycheck-emacs-lisp-load-path

The load path as list of strings. Relative directories are expanded against the default-directory of the buffer being checked.

defcustom flycheck-emacs-lisp-initialize-packages

Whether to initialize Emacs’ package manager with package-initialize before checking the buffer. If set to auto (the default), only initialize the package managers when checking files under user-emacs-directory.

defcustom flycheck-emacs-lisp-package-user-dir

The package directory as string. Has no effect if flycheck-emacs-lisp-initialize-packages is nil.

emacs-lisp-checkdoc

Check Emacs Lisp documentation conventions with checkdoc.

See also

Documentation Tips(elisp)
Information about documentation conventions for Emacs Lisp.
purcell/flycheck-package
Flycheck extension which adds a syntax checker to check for violation of Emacs Lisp library headers and packaging conventions.
Library Headers(elisp)
Information about library headers for Emacs Lisp files.

Erlang

Flycheck checks Erlang with erlang-rebar3 in rebar projects and erlang otherwise.

erlang

Check Erlang with the standard Erlang compiler.

defcustom flycheck-erlang-include-path

A list of include directories.

defcustom flycheck-erlang-library-path

A list of library directories.

erlang-rebar3

Check Erlang with the rebar3 build tool.

ERuby

eruby-erubis

Check ERuby with erubis.

Fortran

fortran-gfortran

Check Fortran syntax and type with GFortran.

defcustom flycheck-gfortran-args

A list of additional arguments.

defcustom flycheck-gfortran-include-path

A list of include directories. Relative paths are relative to the file being checked.

defcustom flycheck-gfortran-language-standard

The language standard to use via the -std option.

defcustom flycheck-gfortran-layout

The source code layout to use. Set to free or fixed for free or fixed layout respectively, or nil (the default) to let GFortran automatically determine the layout.

defcustom flycheck-gfortran-warnings

A list of warnings enabled via the -W option.

Go

Flycheck checks Go with the following checkers:

  1. go-gofmt
  2. go-golint
  3. go-vet
  4. go-build or go-test
  5. go-errcheck
  6. go-unconvert
go-gofmt

Check Go syntax with gofmt.

go-golint

Check Go code style with Golint.

go-vet

Check Go for suspicious code with vet.

defcustom flycheck-go-vet-print-functions

A list of print-like functions to check calls for format string problems.

defcustom flycheck-go-vet-shadow

Whether to check for shadowed variables, in Go 1.6 or newer.

defcustom flycheck-go-build-tags

A list of build tags.

go-build

Check syntax and type with the Go compiler.

Note

This syntax checker requires Go 1.6 or newer.

defcustom flycheck-go-build-install-deps

Whether to install dependencies while checking with go-build or go-test

defcustom flycheck-go-build-tags

See flycheck-go-build-tags

go-test

Check syntax and types of Go tests with the Go compiler.

Note

This syntax checker requires Go 1.6 or newer.

defcustom flycheck-go-build-install-deps

See flycheck-go-build-install-deps.

defcustom flycheck-go-build-tags

See flycheck-go-build-tags

go-errcheck

Check for unhandled error returns in Go with errcheck.

Note

This syntax checker requires errcheck build from commit 8515d34 (Aug 28th, 2015) or newer.

defcustom flycheck-go-build-tags

See flycheck-go-build-tags

go-unconvert

Check for unnecessary type conversions with unconvert.

Groovy

groovy

Check syntax using the Groovy compiler.

Haml

haml

Check syntax with the Haml compiler.

Handlebars

handlebars

Check syntax with the Handlebars compiler.

Haskell

Flycheck checks Haskell with haskell-stack-ghc (in Stack projects) or haskell-ghc, and then with haskell-hlint.

See also

flycheck-haskell
Flycheck extension to configure Flycheck’s Haskell checkers from the metadata, with support for Cabal sandboxes.
flycheck-hdevtools
Flycheck extension which adds an alternative syntax checker for GHC using hdevtools.
haskell-stack-ghc
haskell-ghc

Check syntax and type GHC. In Stack projects invoke GHC through Stack to bring package dependencies from Stack in.

defcustom flycheck-ghc-args

A list of additional arguments.

defcustom flycheck-ghc-no-user-package-database

Whether to disable the user package database (only for haskell-ghc).

defcustom flycheck-ghc-stack-use-nix

Whether to enable Nix support for Stack (only for haskell-stack-ghc).

defcustom flycheck-ghc-package-databases

A list of additional package databases for GHC (only for haskell-ghc). Each item points to a directory containing a package directory, via -package-db.

defcustom flycheck-ghc-search-path

A list of module directories, via -i.

defcustom flycheck-ghc-language-extensions

A list of language extensions, via -X.

haskell-hlint

Lint with hlint.

defcustom flycheck-hlint-args

A list of additional arguments.

defcustom flycheck-hlint-language-extensions

A list of language extensions to enable.

defcustom flycheck-hlint-ignore-rules

A list of rules to ignore.

defcustom flycheck-hlint-hint-packages

A list of additional hint packages to include.

defcustom flycheck-hlintrc

Configuration file for this syntax checker. See Configuration files.

HTML

html-tidy

Check HTML syntax and style with Tidy HTML5.

defcustom flycheck-tidyrc

Configuration file for this syntax checker. See Configuration files.

Javascript

Flycheck checks Javascript with one of javascript-eslint or javascript-jshint, and then with javascript-jscs.

Alternatively javascript-standard is used instead all of the former ones.

javascript-eslint

Check syntax and lint with ESLint.

Note

Flycheck automatically disables this syntax checker if eslint cannot find a valid configuration file for the current buffer.

defcustom flycheck-eslint-rules-directories

A list of directories with custom rules.

javascript-jshint

Check syntax and lint with JSHint.

defcustom flycheck-jshint-extract-javascript

Whether to extract Javascript from HTML before linting.

defcustom flycheck-jshintrc

Configuration file for this syntax checker. See Configuration files.

javascript-jscs

Check code style with JSCS.

defcustom flycheck-jscsrc

Configuration file for this syntax checker. See Configuration files.

javascript-standard

Check syntax and code style with Standard or Semistandard.

JSON

Flycheck checks JSON with json-jsonlint or json-python-json.

json-jsonlint

Check JSON with jsonlint.

json-python-json

Check JSON with Python’s built-in json module.

Less

less

Check syntax with the Less compiler.

Note

This syntax checker requires lessc 1.4 or newer.

less-stylelint

Syntax-check and lint Less with stylelint.

defcustom flycheck-stylelintrc

Configuration file for this syntax checker. See Configuration files.

defcustom flycheck-stylelint-quiet

Whether to run stylelint in quiet mode via --quiet.

Lua

Flycheck checks Lua with lua-luacheck, falling back to lua.

lua-luacheck

Check syntax and lint with Luacheck.

defcustom flycheck-luacheckrc

Configuration file for this syntax checker. See Configuration files.

defcustom flycheck-luacheck-standards

The luacheck standards to use via one or more --std arguments.

lua

Check syntax with the Lua compiler.

Markdown

markdown-mdl

Check Markdown with markdownlint.

defcustom flycheck-markdown-mdl-rules

A list of enabled rules.

defcustom flycheck-markdown-mdl-tags

A list of enabled rule tags.

defcustom flycheck-markdown-mdl-style

Configuration file for this syntax checker. See Configuration files.

Nix

nix

Check Nix with nix-instantiate.

Perl

Flycheck checks Perl with perl and perl-perlcritic.

perl

Check syntax with the Perl interpreter.

defcustom flycheck-perl-include-path

A list of include directories, relative to the file being checked.

perl-perlcritic

Lint and check style with Perl::Critic.

defcustom flycheck-perlcritic-severity

The severity level as integer for the --severity.

defcustom flycheck-perlcriticrc

Configuration file for this syntax checker. See Configuration files.

PHP

Flycheck checks PHP with php, php-phpmd and php-phpcs.

php

Check syntax with PHP CLI

php-phpmd

Lint with PHP Mess Detector.

defcustom flycheck-phpmd-rulesets

A list of rule sets. Each item is either the name of a default rule set, or the path to a custom rule set file.

php-phpcs

Check style with PHP Code Sniffer.

Note

This syntax checker requires PHP Code Sniffer 2.6 or newer.

defcustom flycheck-phpcs-standard

The coding standard, either as name of a built-in standard, or as path to a standard specification.

Processing

processing

Check syntax using the Processing compiler.

Protobuf

protobuf-protoc

Check syntax using the protoc compiler.

Pug

pug

Check syntax using the Pug compiler.

Puppet

Flycheck checks Puppet with puppet-parser and lints with puppet-lint.

puppet-parser

Check syntax with the Puppet compiler.

puppet-lint

Link with Puppet Lint.

defcustom flycheck-puppet-lint-disabled-checks

A list of checks to disable.

defcustom flycheck-puppet-lint-rc

Configuration file for this syntax checker. See Configuration files.

Python

Flycheck checks Python with python-flake8 or python-pylint, and falls back to python-pycompile if neither of those is available.

See also

flycheck-pyflakes
Flycheck extension which adds a syntax checker using Pyflakes.
python-flake8

Check syntax and lint with flake8.

Note

This syntax checker requires flake8 3.0 or newer.

defcustom flycheck-flake8-error-level-alist

An alist mapping Flake8 error IDs to Flycheck error levels.

defcustom flycheck-flake8-maximum-complexity

The maximum McCabe complexity allowed for methods.

defcustom flycheck-flake8-maximum-line-length

The maximum length of lines.

defcustom flycheck-flake8rc

Configuration file for this syntax checker. See Configuration files.

python-pylint

Check syntax and lint with Pylint.

Note

This syntax checker requires Pylint 1.0 or newer.

defcustom flycheck-pylint-use-symbolic-id

Whether to report symbolic (e.g. no-name-in-module) or numeric (e.g. E0611) message identifiers.

defcustom flycheck-pylintrc

Configuration file for this syntax checker. See Configuration files.

python-pycompile

Check syntax with Python’s byte compiler (see py_compile).

R

r-lintr

Check syntax and lint with lintr.

defcustom flycheck-lintr-caching

Whether to enable caching in lintr. On by default; it is not recommended to disable caching unless it causes actual problems.

defcustom flycheck-lintr-linters

Linters to use as a string with an R expression which selects the linters to use.

Racket

racket

Check syntax with raco expand from the compiler-lib package.

Note

This syntax checker needs the compiler-lib package.

RPM Spec

rpm-rpmlint

Lint with rpmlint.

reStructuredText

Flycheck checks reStructuredText with rst-sphinx in Sphinx projects and with rst otherwise.

rst-sphinx

Check documents with Sphinx.

Note

This syntax checker requires Sphinx 1.2 or newer.

defcustom flycheck-sphinx-warn-on-missing-references

Whether to emit warnings for all missing references.

rst

Check documents with docutils.

Ruby

Flycheck checks Ruby with ruby-rubocop, ruby-reek and ruby-rubylint, falling back to ruby or ruby-jruby for basic syntax checking if those are not available.

ruby-rubocop

Check syntax and lint with RuboCop.

Note

This syntax checker requires Rubocop 0.34 or newer.

defcustom flycheck-rubocop-lint-only

Whether to suppress warnings about style issues, via the --lint option.

defcustom flycheck-rubocoprc

Configuration file for this syntax checker. See Configuration files.

ruby-reek

Check syntax and lint with reek.

defcustom flycheck-reekrc

Configuration file for this syntax checker. See Configuration files.

Note

flycheck-reekrc defaults to nil, because Reek can find its own configuration.

ruby-rubylint

Check syntax and lint with ruby-lint.

Note

This syntax checker requires ruby-lint 2.0.2 or newer.

defcustom flycheck-rubylintrc

Configuration file for this syntax checker. See Configuration files.

ruby

Check syntax with the Ruby interpreter.

ruby-jruby

Check syntax with the JRuby interpreter.

Rust

Flycheck checks Rust with rust-cargo in Cargo projects, or rust otherwise.

rust-cargo
rust

Check syntax and types with the Rust compiler. In a Cargo project the compiler is invoked through cargo rustc to take Cargo dependencies into account.

Note

rust-cargo requires Rust 1.15 or newer. rust requires Rust 1.7 or newer.

See also

flycheck-rust
Flycheck extension to configure Rust syntax checkers according to the current Cargo project.
defcustom flycheck-rust-args

A list of additional arguments that are passed to rustc.

defcustom flycheck-cargo-rustc-args

A list of additional arguments passed to the cargo rustc subcommand

defcustom flycheck-rust-check-tests

Whether to check test code in Rust.

defcustom flycheck-rust-crate-root

A path to the crate root for the current buffer, or nil if the current buffer is a crate by itself.

rust-cargo ignores this option as the crate root is given by Cargo.

defcustom flycheck-rust-crate-type

For rust-cargo, the target type as a string, one of lib, bin, example, test or bench. Can also be nil for projects with a single target.

For rust, the type of the crate to check, as a string for the --crate-type option.

defcustom flycheck-rust-binary-name

The name of the binary to pass to cargo rustc --TARGET-TYPE, as a string.

For rust-cargo, always required unless flycheck-rust-crate-type is lib or nil, in which case it is ignored.

Ignored by rust.

defcustom flycheck-rust-library-path

A list of additional library directories. Relative paths are relative to the buffer being checked.

Sass/SCSS

Flycheck checks SASS with sass/scss-sass-lint, falling back to sass, and SCSS with scss-lint or scss-stylelint falling back to sass/scss-sass-lint first and then scss if neither is available.

scss-lint

Syntax-check and lint SCSS with SCSS-Lint.

Note

This syntax checker requires SCSS-Lint 0.43.2 or newer.

defcustom flycheck-scss-lintrc

Configuration file for this syntax checker. See Configuration files.

sass/scss-sass-lint

Syntax-check and lint Sass/SCSS with SASS-Lint.

defcustom flycheck-sass-lintrc

Configuration file for this syntax checker. See Configuration files.

scss-stylelint

Syntax-check and lint SCSS with stylelint.

defcustom flycheck-stylelintrc

Configuration file for this syntax checker. See Configuration files.

defcustom flycheck-stylelint-quiet

Whether to run stylelint in quiet mode via --quiet.

sass
scss

Check SASS and SCSS respectively with the SCSS compiler.

defcustom flycheck-sass-compass
defcustom flycheck-scss-compass

Whether to enable the Compass CSS framework with --compass.

Scala

Flycheck checks Scala with scala and scala-scalastyle.

scala

Check syntax and types with the Scala compiler.

Note

This syntax checker is fairly primitive. For a better Scala experience we recommend Ensime.

scala-scalastyle

Check style with Scalastyle.

defcustom flycheck-scalastylerc

Configuration file for this syntax checker. See Configuration files.

Important

A configuration file is mandatory for this syntax checker. If flycheck-scalastylerc is not set or the configuration file not found this syntax checker will not be applied.

Scheme

Flycheck checks CHICKEN Scheme files with csc.

scheme-chicken

Check syntax with csc, the CHICKEN Scheme compiler.

Important

Geiser must be installed and active for this checker to work.

Shell scripting languages

Flycheck checks various shell scripting languages:

sh-bash

Check Bash syntax.

sh-posix-dash

Check POSIX shell syntax with Dash.

sh-posix-bash

Check POSIX shell syntax with Bash.

sh-zsh

Check Zsh syntax.

sh-shellcheck

Lint Bash and POSIX shell with ShellCheck.

defcustom flycheck-shellcheck-excluded-warnings

A list of excluded warnings.

defcustom flycheck-shellcheck-follow-sources

Allow shellcheck to read sourced files.

Slim

slim

Check Slim using the Slim compiler.

slim-lint

Check Slim best practices using the slim-lint linter.

SQL

sql-sqlint

Check SQL syntax with Sqlint.

systemd Unit Configuration

systemd-analyze

Check systemd unit configuration file syntax with systemd-analyze.

TeX/LaTeX

Flycheck checks TeX and LaTeX with either tex-chktex or tex-lacheck.

tex-chktex

Check style with ChkTeX.

defcustom flycheck-chktexrc

Configuration file for this syntax checker. See Configuration files.

tex-lacheck

Check style with Lacheck.

Texinfo

texinfo

Check syntax with makeinfo from Texinfo.

TypeScript

typescript-tslint

Check syntax and style with TSLint.

defcustom flycheck-typescript-tslint-config

Configuration file for this syntax checker. See Configuration files.

defcustom flycheck-typescript-tslint-rulesdir

Additional rules directory, for user created rules.

defcustom flycheck-tslint-args

A list of additional arguments that are passed to tslint.

Verilog

verilog-verilator

Check syntax with Verilator.

defcustom flycheck-verilator-include-path

A list of include directories. Relative paths are relative to the file being checked.

XML

Flycheck checks XML with xml-xmlstarlet or xml-xmllint.

xml-xmlstarlet

Check syntax with XMLStarlet.

xml-xmllint

Check syntax with xmllint from Libxml2.

YAML

Flycheck checks YAML with yaml-jsyaml or yaml-ruby.

yaml-jsyaml

Check syntax with js-yaml.

yaml-ruby

Check syntax with Ruby’s YAML parser.