1.97.0.txt (35024B)
1 2 Available lint options: 3 -W <foo> Warn about <foo> 4 -A <foo> Allow <foo> 5 -D <foo> Deny <foo> 6 -F <foo> Forbid <foo> (deny <foo> and all attempts to override) 7 8 9 Lint checks provided by rustc: 10 11 name default meaning 12 ---- ------- ------- 13 absolute-paths-not-starting-with-crate allow fully qualified paths that start with a module name instead of `crate`, `self`, or an extern crate name 14 ambiguous-negative-literals allow ambiguous negative literals operations 15 closure-returning-async-block allow closure that returns `async {}` could be rewritten as an async closure 16 dead-code-pub-in-binary allow detect public items in executable crates that are never used 17 deprecated-in-future allow detects use of items that will be deprecated in a future version 18 deprecated-llvm-intrinsic allow detects uses of deprecated LLVM intrinsics 19 deprecated-safe-2024 allow detects unsafe functions being used as safe functions 20 deref-into-dyn-supertrait allow `Deref` implementation with a supertrait trait object for output is shadowed by trait upcasting 21 edition-2024-expr-fragment-specifier allow The `expr` fragment specifier will accept more expressions in the 2024 edition. To keep the existing behavior, use the `expr_2021` fragment specifier. 22 elided-lifetimes-in-paths allow hidden lifetime parameters in types are deprecated 23 explicit-outlives-requirements allow outlives requirements can be inferred 24 ffi-unwind-calls allow call to foreign functions or function pointers with FFI-unwind ABI 25 fuzzy-provenance-casts allow a fuzzy integer to pointer cast is used 26 if-let-rescope allow `if let` assigns a shorter lifetime to temporary values being pattern-matched against in Edition 2024 and rewriting in `match` is an option to preserve the semantics up to Edition 2021 27 impl-trait-overcaptures allow `impl Trait` will capture more lifetimes than possibly intended in edition 2024 28 impl-trait-redundant-captures allow redundant precise-capturing `use<...>` syntax on an `impl Trait` 29 keyword-idents-2018 allow detects edition keywords being used as an identifier 30 keyword-idents-2024 allow detects edition keywords being used as an identifier 31 let-underscore-drop allow non-binding let on a type that has a destructor 32 linker-info allow linker warnings known to be informational-only and not indicative of a problem 33 lossy-provenance-casts allow a lossy pointer to integer cast is used 34 macro-use-extern-crate allow the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system 35 meta-variable-misuse allow possible meta-variable misuse at macro definition 36 missing-copy-implementations allow detects potentially-forgotten implementations of `Copy` 37 missing-debug-implementations allow detects missing implementations of Debug 38 missing-docs allow detects missing documentation for public members 39 missing-unsafe-on-extern allow detects missing unsafe keyword on extern declarations 40 multiple-supertrait-upcastable allow detect when a dyn-compatible trait has multiple supertraits 41 must-not-suspend allow use of a `#[must_not_suspend]` value across a yield point 42 non-ascii-idents allow detects non-ASCII identifiers 43 non-exhaustive-omitted-patterns allow detect when patterns of types marked `non_exhaustive` are missed 44 redundant-imports allow imports that are redundant due to being imported already 45 redundant-lifetimes allow detects lifetime parameters that are redundant because they are equal to some other named lifetime 46 resolving-to-items-shadowing-supertrait-items allow detects when a supertrait item is shadowed by a subtrait item 47 rust-2021-incompatible-closure-captures allow detects closures affected by Rust 2021 changes 48 rust-2021-incompatible-or-patterns allow detects usage of old versions of or-patterns 49 rust-2021-prefixes-incompatible-syntax allow identifiers that will be parsed as a prefix in Rust 2021 50 rust-2021-prelude-collisions allow detects the usage of trait methods which are ambiguous with traits added to the prelude in future editions 51 rust-2024-guarded-string-incompatible-syntax allow will be parsed as a guarded string in Rust 2024 52 rust-2024-incompatible-pat allow detects patterns whose meaning will change in Rust 2024 53 rust-2024-prelude-collisions allow detects the usage of trait methods which are ambiguous with traits added to the prelude in future editions 54 shadowing-supertrait-items allow detects when a supertrait item is shadowed by a subtrait item 55 single-use-lifetimes allow detects lifetime parameters that are only used once 56 tail-expr-drop-order allow Detect and warn on significant change in drop order in tail expression location 57 trivial-casts allow detects trivial casts which could be removed 58 trivial-numeric-casts allow detects trivial casts of numeric types which could be removed 59 unit-bindings allow binding is useless because it has the unit `()` type 60 unnameable-types allow effective visibility of a type is larger than the area in which it can be named 61 unqualified-local-imports allow `use` of a local item without leading `self::`, `super::`, or `crate::` 62 unreachable-pub allow `pub` items not reachable from crate root 63 unsafe-attr-outside-unsafe allow detects unsafe attributes outside of unsafe 64 unsafe-code allow usage of `unsafe` code and other potentially unsound constructs 65 unsafe-op-in-unsafe-fn allow unsafe operations in unsafe functions without an explicit unsafe block are deprecated 66 unstable-features allow enabling unstable features 67 unused-crate-dependencies allow crate dependencies that are never used 68 unused-extern-crates allow extern crates that are never used 69 unused-import-braces allow unnecessary braces around an imported item 70 unused-lifetimes allow detects lifetime parameters that are never used 71 unused-macro-rules allow detects macro rules that were not used 72 unused-qualifications allow detects unnecessarily qualified names 73 unused-results allow unused result of an expression in a statement 74 variant-size-differences allow detects enums with widely varying variant sizes 75 aarch64-softfloat-neon warn detects code that could be affected by ABI issues on aarch64 softfloat targets 76 ambiguous-derive-helpers warn detects derive helper attributes that are ambiguous with built-in attributes 77 ambiguous-glob-imported-traits warn detects uses of ambiguously glob imported traits 78 ambiguous-glob-reexports warn ambiguous glob re-exports 79 ambiguous-import-visibilities warn detects certain glob imports that require reporting an ambiguity error 80 ambiguous-panic-imports warn detects ambiguous core and std panic imports 81 ambiguous-wide-pointer-comparisons warn detects ambiguous wide pointer comparisons 82 anonymous-parameters warn detects anonymous parameters 83 array-into-iter warn detects calling `into_iter` on arrays in Rust 2015 and 2018 84 asm-sub-register warn using only a subset of a register for inline asm inputs 85 async-fn-in-trait warn use of `async fn` in definition of a publicly-reachable trait 86 bad-asm-style warn incorrect use of inline assembly 87 bare-trait-objects warn suggest using `dyn Trait` for trait objects 88 boxed-slice-into-iter warn detects calling `into_iter` on boxed slices in Rust 2015, 2018, and 2021 89 break-with-label-and-loop warn `break` expression with label and unlabeled loop as value expression 90 clashing-extern-declarations warn detects when an extern fn has been declared with the same name but different types 91 coherence-leak-check warn distinct impls distinguished only by the leak-check code 92 confusable-idents warn detects visually confusable pairs between identifiers 93 const-evaluatable-unchecked warn detects a generic constant is used in a type without a emitting a warning 94 const-item-interior-mutations warn checks for calls which mutates a interior mutable const-item 95 const-item-mutation warn detects attempts to mutate a `const` item 96 dangling-pointers-from-locals warn detects returning a pointer from a local variable 97 dangling-pointers-from-temporaries warn detects getting a pointer from a temporary 98 dead-code warn detect unused, unexported items 99 deprecated warn detects use of deprecated items 100 deprecated-where-clause-location warn deprecated where clause location 101 double-negations warn detects expressions of the form `--x` 102 dropping-copy-types warn calls to `std::mem::drop` with a value that implements Copy 103 dropping-references warn calls to `std::mem::drop` with a reference instead of an owned value 104 drop-bounds warn bounds of the form `T: Drop` are most likely incorrect 105 duplicate-macro-attributes warn duplicated attribute 106 dyn-drop warn trait objects of the form `dyn Drop` are useless 107 ellipsis-inclusive-range-patterns warn `...` range patterns are deprecated 108 exported-private-dependencies warn public interface leaks type from a private dependency 109 float-literal-f32-fallback warn detects unsuffixed floating point literals whose type fallback to `f32` 110 forbidden-lint-groups warn applying forbid to lint-groups 111 forgetting-copy-types warn calls to `std::mem::forget` with a value that implements Copy 112 forgetting-references warn calls to `std::mem::forget` with a reference instead of an owned value 113 for-loops-over-fallibles warn for-looping over an `Option` or a `Result`, which is more clearly expressed as an `if let` 114 function-casts-as-integer warn casting a function into an integer 115 function-item-references warn suggest casting to a function pointer when attempting to take references to function items 116 hidden-glob-reexports warn name introduced by a private item shadows a name introduced by a public glob re-export 117 improper-ctypes warn proper use of libc types in foreign modules 118 improper-ctypes-definitions warn proper use of libc types in foreign item definitions 119 improper-gpu-kernel-arg warn GPU kernel entry points have a limited ABI 120 incomplete-features warn incomplete features that may function improperly in some or all cases 121 inline-no-sanitize warn detects incompatible use of `#[inline(always)]` and `#[sanitize(... = "off")]` 122 integer-to-ptr-transmutes warn detects integer to pointer transmutes 123 internal-eq-trait-method-impls warn manual implementation of the internal `Eq::assert_receiver_is_total_eq` method 124 internal-features warn internal features are not supposed to be used 125 invalid-doc-attributes warn detects invalid `#[doc(...)]` attributes 126 invalid-from-utf8 warn using a non UTF-8 literal in `std::str::from_utf8` 127 invalid-nan-comparisons warn detects invalid floating point NaN comparisons 128 invalid-value warn an invalid value is being created (such as a null reference) 129 irrefutable-let-patterns warn detects irrefutable patterns in `if let` and `while let` statements 130 large-assignments warn detects large moves or copies 131 late-bound-lifetime-arguments warn detects generic lifetime arguments in path segments with late bound lifetime parameters 132 linker-messages warn warnings emitted at runtime by the target-specific linker program 133 malformed-diagnostic-attributes warn detects malformed diagnostic attributes 134 malformed-diagnostic-format-literals warn detects diagnostic attribute with malformed diagnostic format literals 135 map-unit-fn warn `Iterator::map` call that discard the iterator's values 136 mismatched-lifetime-syntaxes warn detects when a lifetime uses different syntax between arguments and return values 137 misplaced-diagnostic-attributes warn detects diagnostic attributes that are placed on the wrong item 138 missing-abi warn No declared ABI for extern declaration 139 missing-gpu-kernel-export-name warn mangled gpu-kernel function 140 mixed-script-confusables warn detects Unicode scripts whose mixed script confusables codepoints are solely used 141 named-arguments-used-positionally warn named arguments in format used positionally 142 non-camel-case-types warn types, variants, traits and type parameters should have camel case names 143 non-contiguous-range-endpoints warn detects off-by-one errors with exclusive range patterns 144 non-fmt-panics warn detect single-argument panic!() invocations in which the argument is not a format string 145 non-local-definitions warn checks for non-local definitions 146 non-shorthand-field-patterns warn using `Struct { x: x }` instead of `Struct { x }` in a pattern 147 non-snake-case warn variables, methods, functions, lifetime parameters and modules should have snake case names 148 non-upper-case-globals warn static constants should have uppercase identifiers 149 noop-method-call warn detects the use of well-known noop methods 150 no-mangle-generic-items warn generic items must be mangled 151 opaque-hidden-inferred-bound warn detects the use of nested `impl Trait` types in associated type bounds that are not general enough 152 overlapping-range-endpoints warn detects range patterns with overlapping endpoints 153 path-statements warn path statements with no effect 154 private-bounds warn private type in secondary interface of an item 155 private-interfaces warn private type in primary interface of an item 156 ptr-to-integer-transmute-in-consts warn detects pointer to integer transmutes in const functions and associated constants 157 redundant-semicolons warn detects unnecessary trailing semicolons 158 refining-impl-trait-internal warn impl trait in impl method signature does not match trait method signature 159 refining-impl-trait-reachable warn impl trait in impl method signature does not match trait method signature 160 renamed-and-removed-lints warn lints that have been renamed or removed 161 repr-c-enums-larger-than-int warn repr(C) enums with discriminant values that do not fit into a C int 162 rtsan-nonblocking-async warn detects incompatible uses of `#[sanitize(realtime = "nonblocking")]` on async functions 163 self-constructor-from-outer-item warn detect unsupported use of `Self` from outer item 164 special-module-name warn module declarations for files with a special meaning 165 stable-features warn stable features found in `#[feature]` directive 166 static-mut-refs warn creating a shared reference to mutable static 167 suspicious-double-ref-op warn suspicious call of trait method on `&&T` 168 tail-call-track-caller warn detects tail calls of functions marked with `#[track_caller]` 169 trivial-bounds warn these bounds don't depend on an type parameters 170 type-alias-bounds warn bounds in type aliases are not enforced 171 tyvar-behind-raw-pointer warn raw pointer to an inference variable 172 uncommon-codepoints warn detects uncommon Unicode codepoints in identifiers 173 unconditional-recursion warn functions that cannot return without calling themselves 174 uncovered-param-in-projection warn impl contains type parameters that are not covered 175 unexpected-cfgs warn detects unexpected names and values in `#[cfg]` conditions 176 unfulfilled-lint-expectations warn unfulfilled lint expectation 177 ungated-async-fn-track-caller warn enabling track_caller on an async fn is a no-op unless the async_fn_track_caller feature is enabled 178 unknown-diagnostic-attributes warn detects unknown diagnostic attributes 179 unknown-lints warn unrecognized lint attribute 180 unnameable-test-items warn detects an item that cannot be named being marked as `#[test_case]` 181 unnecessary-transmutes warn detects transmutes that can also be achieved by other operations 182 unpredictable-function-pointer-comparisons warn detects unpredictable function pointer comparisons 183 unreachable-cfg-select-predicates warn detects unreachable configuration predicates in the cfg_select macro 184 unreachable-code warn detects unreachable code paths 185 unreachable-patterns warn detects unreachable patterns 186 unstable-name-collisions warn detects name collision with an existing but unstable method 187 unstable-syntax-pre-expansion warn unstable syntax can change at any point in the future, causing a hard error! 188 unsupported-calling-conventions warn use of unsupported calling convention 189 unused-allocation warn detects unnecessary allocations that can be eliminated 190 unused-assignments warn detect assignments that will never be read 191 unused-associated-type-bounds warn detects unused `Foo = Bar` bounds in `dyn Trait<Foo = Bar>` 192 unused-attributes warn detects attributes that were not used by the compiler 193 unused-braces warn unnecessary braces around an expression 194 unused-comparisons warn comparisons made useless by limits of the types involved 195 unused-doc-comments warn detects doc comments that aren't used by rustdoc 196 unused-features warn unused features found in crate-level `#[feature]` directives 197 unused-imports warn imports that are never used 198 unused-labels warn detects labels that are never used 199 unused-macros warn detects macros that were not used 200 unused-must-use warn unused result of a type flagged as `#[must_use]` 201 unused-mut warn detect mut variables which don't need to be mutable 202 unused-parens warn `if`, `match`, `while` and `return` do not need parentheses 203 unused-unsafe warn unnecessary use of an `unsafe` block 204 unused-variables warn detect variables which are not used in any way 205 unused-visibilities warn detect visibility qualifiers on `const _` items 206 useless-ptr-null-checks warn useless checking of non-null-typed pointer 207 uses-power-alignment warn Structs do not follow the power alignment rule under repr(C) 208 warnings warn mass-change the level for lints which produce warnings 209 while-true warn suggest using `loop { }` instead of `while true { }` 210 ambiguous-associated-items deny ambiguous associated items 211 ambiguous-glob-imports deny detects certain glob imports that require reporting an ambiguity error 212 arithmetic-overflow deny arithmetic operation overflows 213 binary-asm-labels deny labels in inline assembly containing only 0 or 1 digits 214 bindings-with-variant-name deny detects pattern bindings with the same name as one of the matched variants 215 conflicting-repr-hints deny conflicts between `#[repr(..)]` hints that were previously accepted and used in practice 216 dangerous-implicit-autorefs deny implicit reference to a dereference of a raw pointer 217 default-overrides-default-fields deny detect `Default` impl that should use the type's default field values 218 dependency-on-unit-never-type-fallback deny never type fallback affecting unsafe function calls 219 deref-nullptr deny detects when an null pointer is dereferenced 220 duplicate-features deny duplicate features found in crate-level `#[feature]` directives 221 elided-lifetimes-in-associated-constant deny elided lifetimes cannot be used in associated constants in impls 222 enum-intrinsics-non-enums deny detects calls to `core::mem::discriminant` and `core::mem::variant_count` with non-enum types 223 explicit-builtin-cfgs-in-flags deny detects builtin cfgs set via the `--cfg` 224 ill-formed-attribute-input deny ill-formed attribute inputs that were previously accepted and used in practice 225 incomplete-include deny trailing content in included file 226 ineffective-unstable-trait-impl deny detects `#[unstable]` on stable trait implementations for stable types 227 invalid-atomic-ordering deny usage of invalid atomic ordering in atomic operations and memory fences 228 invalid-from-utf8-unchecked deny using a non UTF-8 literal in `std::str::from_utf8_unchecked` 229 invalid-macro-export-arguments deny "invalid_parameter" isn't a valid argument for `#[macro_export]` 230 invalid-null-arguments deny invalid null pointer in arguments 231 invalid-reference-casting deny casts of `&T` to `&mut T` without interior mutability 232 invalid-type-param-default deny type parameter default erroneously allowed in invalid location 233 legacy-derive-helpers deny detects derive helper attributes that are used before they are introduced 234 let-underscore-lock deny non-binding let on a synchronization lock 235 long-running-const-eval deny detects long const eval operations 236 macro-expanded-macro-exports-accessed-by-absolute-paths deny macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths 237 mutable-transmutes deny transmuting &T to &mut T is undefined behavior, even if the reference is unused 238 named-asm-labels deny named labels in inline assembly 239 never-type-fallback-flowing-into-unsafe deny never type fallback affecting unsafe function calls 240 no-mangle-const-items deny const items will not have their symbols exported 241 out-of-scope-macro-calls deny detects out of scope calls to `macro_rules` in key-value attributes 242 overflowing-literals deny literal out of range for its type 243 patterns-in-fns-without-body deny patterns in functions without body were erroneously allowed 244 proc-macro-derive-resolution-fallback deny detects proc macro derives using inaccessible names from parent modules 245 pub-use-of-private-extern-crate deny detect public re-exports of private extern crates 246 repr-transparent-non-zst-fields deny transparent type contains an external ZST that is marked #[non_exhaustive] or contains private fields 247 semicolon-in-expressions-from-macros deny trailing semicolon in macro body used as expression 248 test-unstable-lint deny this unstable lint is only for testing 249 text-direction-codepoint-in-comment deny invisible directionality-changing codepoints in comment 250 text-direction-codepoint-in-literal deny detect special Unicode codepoints that affect the visual representation of text on screen, changing the direction in which text flows 251 unconditional-panic deny operation will cause a panic at runtime 252 undropped-manually-drops deny calls to `std::mem::drop` with `std::mem::ManuallyDrop` instead of it's inner value 253 uninhabited-static deny uninhabited static 254 unknown-crate-types deny unknown crate type found in `#[crate_type]` directive 255 useless-deprecated deny detects deprecation attributes with no effect 256 varargs-without-pattern deny detects usage of `...` arguments without a pattern in non-foreign items 257 258 259 Lint groups provided by rustc: 260 261 name sub-lints 262 ---- --------- 263 warnings all lints that are set to issue warnings 264 deprecated-safe deprecated-safe-2024 265 future-incompatible internal-eq-trait-method-impls, aarch64-softfloat-neon, ambiguous-associated-items, ambiguous-derive-helpers, ambiguous-glob-imported-traits, ambiguous-glob-imports, ambiguous-import-visibilities, ambiguous-panic-imports, coherence-leak-check, conflicting-repr-hints, const-evaluatable-unchecked, elided-lifetimes-in-associated-constant, float-literal-f32-fallback, forbidden-lint-groups, ill-formed-attribute-input, invalid-macro-export-arguments, invalid-type-param-default, late-bound-lifetime-arguments, legacy-derive-helpers, macro-expanded-macro-exports-accessed-by-absolute-paths, out-of-scope-macro-calls, patterns-in-fns-without-body, proc-macro-derive-resolution-fallback, pub-use-of-private-extern-crate, repr-c-enums-larger-than-int, repr-transparent-non-zst-fields, self-constructor-from-outer-item, semicolon-in-expressions-from-macros, uncovered-param-in-projection, uninhabited-static, unstable-name-collisions, unstable-syntax-pre-expansion, unsupported-calling-conventions, varargs-without-pattern 266 keyword-idents keyword-idents-2018, keyword-idents-2024 267 let-underscore let-underscore-drop, let-underscore-lock 268 nonstandard-style non-camel-case-types, non-snake-case, non-upper-case-globals 269 refining-impl-trait refining-impl-trait-reachable, refining-impl-trait-internal 270 rust-2018-compatibility keyword-idents-2018, anonymous-parameters, absolute-paths-not-starting-with-crate, tyvar-behind-raw-pointer 271 rust-2018-idioms bare-trait-objects, unused-extern-crates, ellipsis-inclusive-range-patterns, elided-lifetimes-in-paths, explicit-outlives-requirements 272 rust-2021-compatibility ellipsis-inclusive-range-patterns, array-into-iter, non-fmt-panics, bare-trait-objects, rust-2021-incompatible-closure-captures, rust-2021-incompatible-or-patterns, rust-2021-prefixes-incompatible-syntax, rust-2021-prelude-collisions 273 rust-2024-compatibility keyword-idents-2024, edition-2024-expr-fragment-specifier, boxed-slice-into-iter, impl-trait-overcaptures, if-let-rescope, static-mut-refs, dependency-on-unit-never-type-fallback, deprecated-safe-2024, missing-unsafe-on-extern, never-type-fallback-flowing-into-unsafe, rust-2024-guarded-string-incompatible-syntax, rust-2024-incompatible-pat, rust-2024-prelude-collisions, tail-expr-drop-order, unsafe-attr-outside-unsafe, unsafe-op-in-unsafe-fn 274 unknown-or-malformed-diagnostic-attributes malformed-diagnostic-attributes, malformed-diagnostic-format-literals, misplaced-diagnostic-attributes, unknown-diagnostic-attributes 275 unused unused-imports, unused-variables, unused-visibilities, unused-assignments, dead-code, unused-mut, unreachable-code, unreachable-patterns, unused-must-use, unused-unsafe, path-statements, unused-attributes, unused-macros, unused-macro-rules, unused-allocation, unused-doc-comments, unused-extern-crates, unused-features, unused-labels, unused-parens, unused-braces, redundant-semicolons, map-unit-fn 276 277 278 Lint tools like Clippy can load additional lints and lint groups.