Lint Configuration Options

The following list shows each configuration option, along with a description, its default value, an example and lints affected.

`arithmetic-side-effects-allowed`

Suppress checking of the passed type names in all types of operations.

If a specific operation is desired, consider using arithmetic_side_effects_allowed_binary or arithmetic_side_effects_allowed_unary instead.

Example

arithmetic-side-effects-allowed = ["SomeType", "AnotherType"]

Noteworthy

A type, say SomeType, listed in this configuration has the same behavior of ["SomeType" , "*"], ["*", "SomeType"] in arithmetic_side_effects_allowed_binary.

Default Value: {} (rustc_data_structures::fx::FxHashSet<String>)

Affected lints:

arithmetic_side_effects

`arithmetic-side-effects-allowed-binary`

Suppress checking of the passed type pair names in binary operations like addition or multiplication.

Supports the "*" wildcard to indicate that a certain type won't trigger the lint regardless of the involved counterpart. For example, ["SomeType", "*"] or ["*", "AnotherType"].

Pairs are asymmetric, which means that ["SomeType", "AnotherType"] is not the same as ["AnotherType", "SomeType"].

Example

arithmetic-side-effects-allowed-binary = [["SomeType" , "f32"], ["AnotherType", "*"]]

Default Value: [] (Vec<[String; 2]>)

Affected lints:

arithmetic_side_effects

`arithmetic-side-effects-allowed-unary`

Suppress checking of the passed type names in unary operations like "negation" (-).

Example

arithmetic-side-effects-allowed-unary = ["SomeType", "AnotherType"]

Default Value: {} (rustc_data_structures::fx::FxHashSet<String>)

Affected lints:

arithmetic_side_effects

`avoid-breaking-exported-api`

Suppress lints whenever the suggested change would cause breakage for other crates.

Default Value: true (bool)

Affected lints:

`msrv`

The minimum rust version that the project supports

Default Value: None (Option<String>)

Affected lints:

`cognitive-complexity-threshold`

The maximum cognitive complexity a function can have

Default Value: 25 (u64)

Affected lints:

cognitive_complexity

`excessive-nesting-threshold`

The maximum amount of nesting a block can reside in

Default Value: 0 (u64)

Affected lints:

excessive_nesting

The list of disallowed names to lint about. NB: bar is not here since it has legitimate uses. The value ".." can be used as part of the list to indicate that the configured values should be appended to the default configuration of Clippy. By default, any configuration will replace the default value.

Default Value: ["foo", "baz", "quux"] (Vec<String>)

Affected lints:

disallowed_names

`semicolon-inside-block-ignore-singleline`

Whether to lint only if it's multiline.

Default Value: false (bool)

Affected lints:

semicolon_inside_block

`semicolon-outside-block-ignore-multiline`

Whether to lint only if it's singleline.

Default Value: false (bool)

Affected lints:

semicolon_outside_block

`doc-valid-idents`

The list of words this lint should not consider as identifiers needing ticks. The value ".." can be used as part of the list to indicate, that the configured values should be appended to the default configuration of Clippy. By default, any configuration will replace the default value. For example:

doc-valid-idents = ["ClipPy"] would replace the default list with ["ClipPy"].
doc-valid-idents = ["ClipPy", ".."] would append ClipPy to the default list.

Default list:

Default Value: ["KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "DirectX", "ECMAScript", "GPLv2", "GPLv3", "GitHub", "GitLab", "IPv4", "IPv6", "ClojureScript", "CoffeeScript", "JavaScript", "PureScript", "TypeScript", "WebAssembly", "NaN", "NaNs", "OAuth", "GraphQL", "OCaml", "OpenGL", "OpenMP", "OpenSSH", "OpenSSL", "OpenStreetMap", "OpenDNS", "WebGL", "TensorFlow", "TrueType", "iOS", "macOS", "FreeBSD", "TeX", "LaTeX", "BibTeX", "BibLaTeX", "MinGW", "CamelCase"] (Vec<String>)

Affected lints:

doc_markdown

`too-many-arguments-threshold`

The maximum number of argument a function or method can have

Default Value: 7 (u64)

Affected lints:

too_many_arguments

`type-complexity-threshold`

The maximum complexity a type can have

Default Value: 250 (u64)

Affected lints:

type_complexity

`single-char-binding-names-threshold`

The maximum number of single char bindings a scope may have

Default Value: 4 (u64)

Affected lints:

many_single_char_names

`too-large-for-stack`

The maximum size of objects (in bytes) that will be linted. Larger objects are ok on the heap

Default Value: 200 (u64)

Affected lints:

`enum-variant-name-threshold`

The minimum number of enum variants for the lints about variant names to trigger

Default Value: 3 (u64)

Affected lints:

enum_variant_names

`enum-variant-size-threshold`

The maximum size of an enum's variant to avoid box suggestion

Default Value: 200 (u64)

Affected lints:

large_enum_variant

`verbose-bit-mask-threshold`

The maximum allowed size of a bit mask before suggesting to use 'trailing_zeros'

Default Value: 1 (u64)

Affected lints:

verbose_bit_mask

`literal-representation-threshold`

The lower bound for linting decimal literals

Default Value: 16384 (u64)

Affected lints:

decimal_literal_representation

`trivial-copy-size-limit`

The maximum size (in bytes) to consider a Copy type for passing by value instead of by reference.

Default Value: None (Option<u64>)

Affected lints:

trivially_copy_pass_by_ref

`pass-by-value-size-limit`

The minimum size (in bytes) to consider a type for passing by reference instead of by value.

Default Value: 256 (u64)

Affected lints:

large_types_passed_by_value

`too-many-lines-threshold`

The maximum number of lines a function or method can have

Default Value: 100 (u64)

Affected lints:

too_many_lines

`array-size-threshold`

The maximum allowed size for arrays on the stack

Default Value: 512000 (u64)

Affected lints:

`stack-size-threshold`

The maximum allowed stack size for functions in bytes

Default Value: 512000 (u64)

Affected lints:

large_stack_frames

`vec-box-size-threshold`

The size of the boxed type in bytes, where boxing in a Vec is allowed

Default Value: 4096 (u64)

Affected lints:

vec_box

`max-trait-bounds`

The maximum number of bounds a trait can have to be linted

Default Value: 3 (u64)

Affected lints:

type_repetition_in_bounds

`max-struct-bools`

The maximum number of bool fields a struct can have

Default Value: 3 (u64)

Affected lints:

struct_excessive_bools

`max-fn-params-bools`

The maximum number of bool parameters a function can have

Default Value: 3 (u64)

Affected lints:

fn_params_excessive_bools

`warn-on-all-wildcard-imports`

Whether to allow certain wildcard imports (prelude, super in tests).

Default Value: false (bool)

Affected lints:

wildcard_imports

`disallowed-macros`

The list of disallowed macros, written as fully qualified paths.

Default Value: [] (Vec<crate::utils::conf::DisallowedPath>)

Affected lints:

disallowed_macros

`disallowed-methods`

The list of disallowed methods, written as fully qualified paths.

Default Value: [] (Vec<crate::utils::conf::DisallowedPath>)

Affected lints:

disallowed_methods

`disallowed-types`

The list of disallowed types, written as fully qualified paths.

Default Value: [] (Vec<crate::utils::conf::DisallowedPath>)

Affected lints:

disallowed_types

`unreadable-literal-lint-fractions`

Should the fraction of a decimal be linted to include separators.

Default Value: true (bool)

Affected lints:

unreadable_literal

`upper-case-acronyms-aggressive`

Enables verbose mode. Triggers if there is more than one uppercase char next to each other

Default Value: false (bool)

Affected lints:

upper_case_acronyms

`matches-for-let-else`

Whether the matches should be considered by the lint, and whether there should be filtering for common types.

Default Value: WellKnownTypes (crate::manual_let_else::MatchLintBehaviour)

Affected lints:

manual_let_else

`cargo-ignore-publish`

For internal testing only, ignores the current publish settings in the Cargo manifest.

Default Value: false (bool)

Affected lints:

_cargo_common_metadata

`standard-macro-braces`

Enforce the named macros always use the braces specified.

A MacroMatcher can be added like so { name = "macro_name", brace = "(" }. If the macro could be used with a full path two MacroMatchers have to be added one with the full path crate_name::macro_name and one with just the macro name.

Default Value: [] (Vec<crate::nonstandard_macro_braces::MacroMatcher>)

Affected lints:

nonstandard_macro_braces

`enforced-import-renames`

The list of imports to always rename, a fully qualified path followed by the rename.

Default Value: [] (Vec<crate::utils::conf::Rename>)

Affected lints:

missing_enforced_import_renames

`allowed-scripts`

The list of unicode scripts allowed to be used in the scope.

Default Value: ["Latin"] (Vec<String>)

Affected lints:

disallowed_script_idents

`enable-raw-pointer-heuristic-for-send`

Whether to apply the raw pointer heuristic to determine if a type is Send.

Default Value: true (bool)

Affected lints:

non_send_fields_in_send_ty

`max-suggested-slice-pattern-length`

When Clippy suggests using a slice pattern, this is the maximum number of elements allowed in the slice pattern that is suggested. If more elements are necessary, the lint is suppressed. For example, [_, _, _, e, ..] is a slice pattern with 4 elements.

Default Value: 3 (u64)

Affected lints:

index_refutable_slice

`await-holding-invalid-types`

Default Value: [] (Vec<crate::utils::conf::DisallowedPath>)

Affected lints:

await_holding_invalid_type

`max-include-file-size`

The maximum size of a file included via include_bytes!() or include_str!(), in bytes

Default Value: 1000000 (u64)

Affected lints:

large_include_file

`allow-expect-in-tests`

Whether expect should be allowed in test functions or #[cfg(test)]

Default Value: false (bool)

Affected lints:

expect_used

`allow-unwrap-in-tests`

Whether unwrap should be allowed in test functions or #[cfg(test)]

Default Value: false (bool)

Affected lints:

unwrap_used

`allow-dbg-in-tests`

Whether dbg! should be allowed in test functions or #[cfg(test)]

Default Value: false (bool)

Affected lints:

dbg_macro

`allow-print-in-tests`

Whether print macros (ex. println!) should be allowed in test functions or #[cfg(test)]

Default Value: false (bool)

Affected lints:

`large-error-threshold`

The maximum size of the Err-variant in a Result returned from a function

Default Value: 128 (u64)

Affected lints:

result_large_err

`ignore-interior-mutability`

A list of paths to types that should be treated like Arc, i.e. ignored but for the generic parameters for determining interior mutability

Default Value: ["bytes::Bytes"] (Vec<String>)

Affected lints:

`allow-mixed-uninlined-format-args`

Whether to allow mixed uninlined format args, e.g. format!("{} {}", a, foo.bar)

Default Value: true (bool)

Affected lints:

uninlined_format_args

`suppress-restriction-lint-in-const`

Whether to suppress a restriction lint in constant code. In same cases the restructured operation might not be unavoidable, as the suggested counterparts are unavailable in constant code. This configuration will cause restriction lints to trigger even if no suggestion can be made.

Default Value: false (bool)

Affected lints:

indexing_slicing

`missing-docs-in-crate-items`

Whether to only check for missing documentation in items visible within the current crate. For example, pub(crate) items.

Default Value: false (bool)

Affected lints:

missing_docs_in_private_items

`future-size-threshold`

The maximum byte size a Future can have, before it triggers the clippy::large_futures lint

Default Value: 16384 (u64)

Affected lints:

large_futures

`unnecessary-box-size`

The byte size a T in Box<T> can have, below which it triggers the clippy::unnecessary_box lint

Default Value: 128 (u64)

Affected lints:

unnecessary_box_returns

`allow-private-module-inception`

Whether to allow module inception if it's not public.

Default Value: false (bool)

Affected lints:

module_inception

`allowed-idents-below-min-chars`

Allowed names below the minimum allowed characters. The value ".." can be used as part of the list to indicate, that the configured values should be appended to the default configuration of Clippy. By default, any configuration will replace the default value.

Default Value: {"j", "z", "i", "y", "n", "x", "w"} (rustc_data_structures::fx::FxHashSet<String>)

Affected lints:

min_ident_chars

`min-ident-chars-threshold`

Minimum chars an ident can have, anything below or equal to this will be linted.

Default Value: 1 (u64)

Affected lints:

min_ident_chars

`accept-comment-above-statement`

Whether to accept a safety comment to be placed above the statement containing the unsafe block

Default Value: true (bool)

Affected lints:

undocumented_unsafe_blocks

`accept-comment-above-attributes`

Whether to accept a safety comment to be placed above the attributes for the unsafe block

Default Value: true (bool)

Affected lints:

undocumented_unsafe_blocks

`allow-one-hash-in-raw-strings`

Whether to allow r#""# when r"" can be used

Default Value: false (bool)

Affected lints:

unnecessary_raw_string_hashes

`absolute-paths-max-segments`

The maximum number of segments a path can have before being linted, anything above this will be linted.

Default Value: 2 (u64)

Affected lints:

absolute_paths

`absolute-paths-allowed-crates`

Which crates to allow absolute paths from

Default Value: {} (rustc_data_structures::fx::FxHashSet<String>)

Affected lints:

absolute_paths

`allowed-dotfiles`

Additional dotfiles (files or directories starting with a dot) to allow

Default Value: {} (rustc_data_structures::fx::FxHashSet<String>)

Affected lints:

path_ends_with_ext

`enforce-iter-loop-reborrow`

Example

let mut vec = vec![1, 2, 3];
let rmvec = &mut vec;
for _ in rmvec.iter() {}
for _ in rmvec.iter_mut() {}

Use instead:

let mut vec = vec![1, 2, 3];
let rmvec = &mut vec;
for _ in &*rmvec {}
for _ in &mut *rmvec {}

Default Value: false (bool)

Affected lints:

explicit_iter_loop

Clippy Documentation