1.79.0.txt (28098B)
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 box-pointers allow use of owned (Box type) heap memory 15 deprecated-in-future allow detects use of items that will be deprecated in a future version 16 dereferencing-mut-binding allow detects `mut x` bindings that change the type of `x` 17 elided-lifetimes-in-paths allow hidden lifetime parameters in types are deprecated 18 explicit-outlives-requirements allow outlives requirements can be inferred 19 ffi-unwind-calls allow call to foreign functions or function pointers with FFI-unwind ABI 20 fuzzy-provenance-casts allow a fuzzy integer to pointer cast is used 21 keyword-idents-2018 allow detects edition keywords being used as an identifier 22 keyword-idents-2024 allow detects edition keywords being used as an identifier 23 let-underscore-drop allow non-binding let on a type that implements `Drop` 24 lossy-provenance-casts allow a lossy pointer to integer cast is used 25 macro-use-extern-crate allow the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system 26 meta-variable-misuse allow possible meta-variable misuse at macro definition 27 missing-abi allow No declared ABI for extern declaration 28 missing-copy-implementations allow detects potentially-forgotten implementations of `Copy` 29 missing-debug-implementations allow detects missing implementations of Debug 30 missing-docs allow detects missing documentation for public members 31 multiple-supertrait-upcastable allow detect when an object-safe trait has multiple supertraits 32 must-not-suspend allow use of a `#[must_not_suspend]` value across a yield point 33 non-ascii-idents allow detects non-ASCII identifiers 34 non-exhaustive-omitted-patterns allow detect when patterns of types marked `non_exhaustive` are missed 35 non-local-definitions allow checks for non-local definitions 36 redundant-lifetimes allow detects lifetime parameters that are redundant because they are equal to some other named lifetime 37 rust-2021-incompatible-closure-captures allow detects closures affected by Rust 2021 changes 38 rust-2021-incompatible-or-patterns allow detects usage of old versions of or-patterns 39 rust-2021-prefixes-incompatible-syntax allow identifiers that will be parsed as a prefix in Rust 2021 40 rust-2021-prelude-collisions allow detects the usage of trait methods which are ambiguous with traits added to the prelude in future editions 41 single-use-lifetimes allow detects lifetime parameters that are only used once 42 trivial-casts allow detects trivial casts which could be removed 43 trivial-numeric-casts allow detects trivial casts of numeric types which could be removed 44 unit-bindings allow binding is useless because it has the unit `()` type 45 unnameable-types allow effective visibility of a type is larger than the area in which it can be named 46 unreachable-pub allow `pub` items not reachable from crate root 47 unsafe-code allow usage of `unsafe` code and other potentially unsound constructs 48 unsafe-op-in-unsafe-fn allow unsafe operations in unsafe functions without an explicit unsafe block are deprecated 49 unstable-features allow enabling unstable features 50 unused-crate-dependencies allow crate dependencies that are never used 51 unused-extern-crates allow extern crates that are never used 52 unused-import-braces allow unnecessary braces around an imported item 53 unused-lifetimes allow detects lifetime parameters that are never used 54 unused-macro-rules allow detects macro rules that were not used 55 unused-qualifications allow detects unnecessarily qualified names 56 unused-results allow unused result of an expression in a statement 57 variant-size-differences allow detects enums with widely varying variant sizes 58 ambiguous-glob-imports warn detects certain glob imports that require reporting an ambiguity error 59 ambiguous-glob-reexports warn ambiguous glob re-exports 60 ambiguous-wide-pointer-comparisons warn detects ambiguous wide pointer comparisons 61 anonymous-parameters warn detects anonymous parameters 62 array-into-iter warn detects calling `into_iter` on arrays in Rust 2015 and 2018 63 asm-sub-register warn using only a subset of a register for inline asm inputs 64 async-fn-in-trait warn use of `async fn` in definition of a publicly-reachable trait 65 bad-asm-style warn incorrect use of inline assembly 66 bare-trait-objects warn suggest using `dyn Trait` for trait objects 67 break-with-label-and-loop warn `break` expression with label and unlabeled loop as value expression 68 byte-slice-in-packed-struct-with-derive warn `[u8]` or `str` used in a packed struct with `derive` 69 clashing-extern-declarations warn detects when an extern fn has been declared with the same name but different types 70 coherence-leak-check warn distinct impls distinguished only by the leak-check code 71 confusable-idents warn detects visually confusable pairs between identifiers 72 const-evaluatable-unchecked warn detects a generic constant is used in a type without a emitting a warning 73 const-eval-mutable-ptr-in-final-value warn detects a mutable pointer that has leaked into final value of a const expression 74 const-item-mutation warn detects attempts to mutate a `const` item 75 dead-code warn detect unused, unexported items 76 deprecated warn detects use of deprecated items 77 deprecated-where-clause-location warn deprecated where clause location 78 deref-into-dyn-supertrait warn `Deref` implementation usage with a supertrait trait object for output might be shadowed in the future 79 deref-nullptr warn detects when an null pointer is dereferenced 80 dropping-copy-types warn calls to `std::mem::drop` with a value that implements Copy 81 dropping-references warn calls to `std::mem::drop` with a reference instead of an owned value 82 drop-bounds warn bounds of the form `T: Drop` are most likely incorrect 83 duplicate-macro-attributes warn duplicated attribute 84 dyn-drop warn trait objects of the form `dyn Drop` are useless 85 elided-lifetimes-in-associated-constant warn elided lifetimes cannot be used in associated constants in impls 86 ellipsis-inclusive-range-patterns warn `...` range patterns are deprecated 87 exported-private-dependencies warn public interface leaks type from a private dependency 88 forbidden-lint-groups warn applying forbid to lint-groups 89 forgetting-copy-types warn calls to `std::mem::forget` with a value that implements Copy 90 forgetting-references warn calls to `std::mem::forget` with a reference instead of an owned value 91 for-loops-over-fallibles warn for-looping over an `Option` or a `Result`, which is more clearly expressed as an `if let` 92 function-item-references warn suggest casting to a function pointer when attempting to take references to function items 93 hidden-glob-reexports warn name introduced by a private item shadows a name introduced by a public glob re-export 94 improper-ctypes warn proper use of libc types in foreign modules 95 improper-ctypes-definitions warn proper use of libc types in foreign item definitions 96 incomplete-features warn incomplete features that may function improperly in some or all cases 97 indirect-structural-match warn constant used in pattern contains value of non-structural-match type in a field or a variant 98 inline-no-sanitize warn detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]` 99 internal-features warn internal features are not supposed to be used 100 invalid-from-utf8 warn using a non UTF-8 literal in `std::str::from_utf8` 101 invalid-macro-export-arguments warn "invalid_parameter" isn't a valid argument for `#[macro_export]` 102 invalid-nan-comparisons warn detects invalid floating point NaN comparisons 103 invalid-value warn an invalid value is being created (such as a null reference) 104 irrefutable-let-patterns warn detects irrefutable patterns in `if let` and `while let` statements 105 large-assignments warn detects large moves or copies 106 late-bound-lifetime-arguments warn detects generic lifetime arguments in path segments with late bound lifetime parameters 107 legacy-derive-helpers warn detects derive helper attributes that are used before they are introduced 108 map-unit-fn warn `Iterator::map` call that discard the iterator's values 109 mixed-script-confusables warn detects Unicode scripts whose mixed script confusables codepoints are solely used 110 named-arguments-used-positionally warn named arguments in format used positionally 111 non-camel-case-types warn types, variants, traits and type parameters should have camel case names 112 non-contiguous-range-endpoints warn detects off-by-one errors with exclusive range patterns 113 non-fmt-panics warn detect single-argument panic!() invocations in which the argument is not a format string 114 non-shorthand-field-patterns warn using `Struct { x: x }` instead of `Struct { x }` in a pattern 115 non-snake-case warn variables, methods, functions, lifetime parameters and modules should have snake case names 116 non-upper-case-globals warn static constants should have uppercase identifiers 117 noop-method-call warn detects the use of well-known noop methods 118 no-mangle-generic-items warn generic items must be mangled 119 opaque-hidden-inferred-bound warn detects the use of nested `impl Trait` types in associated type bounds that are not general enough 120 overlapping-range-endpoints warn detects range patterns with overlapping endpoints 121 path-statements warn path statements with no effect 122 pointer-structural-match warn pointers are not structural-match 123 private-bounds warn private type in secondary interface of an item 124 private-interfaces warn private type in primary interface of an item 125 redundant-semicolons warn detects unnecessary trailing semicolons 126 refining-impl-trait-internal warn impl trait in impl method signature does not match trait method signature 127 refining-impl-trait-reachable warn impl trait in impl method signature does not match trait method signature 128 renamed-and-removed-lints warn lints that have been renamed or removed 129 repr-transparent-external-private-fields warn transparent type contains an external ZST that is marked #[non_exhaustive] or contains private fields 130 semicolon-in-expressions-from-macros warn trailing semicolon in macro body used as expression 131 special-module-name warn module declarations for files with a special meaning 132 stable-features warn stable features found in `#[feature]` directive 133 static-mut-refs warn shared references or mutable references of mutable static is discouraged 134 suspicious-double-ref-op warn suspicious call of trait method on `&&T` 135 temporary-cstring-as-ptr warn detects getting the inner pointer of a temporary `CString` 136 trivial-bounds warn these bounds don't depend on an type parameters 137 type-alias-bounds warn bounds in type aliases are not enforced 138 tyvar-behind-raw-pointer warn raw pointer to an inference variable 139 uncommon-codepoints warn detects uncommon Unicode codepoints in identifiers 140 unconditional-recursion warn functions that cannot return without calling themselves 141 undefined-naked-function-abi warn undefined naked function ABI 142 unexpected-cfgs warn detects unexpected names and values in `#[cfg]` conditions 143 unfulfilled-lint-expectations warn unfulfilled lint expectation 144 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 145 uninhabited-static warn uninhabited static 146 unknown-lints warn unrecognized lint attribute 147 unknown-or-malformed-diagnostic-attributes warn unrecognized or malformed diagnostic attribute 148 unnameable-test-items warn detects an item that cannot be named being marked as `#[test_case]` 149 unreachable-code warn detects unreachable code paths 150 unreachable-patterns warn detects unreachable patterns 151 unstable-name-collisions warn detects name collision with an existing but unstable method 152 unstable-syntax-pre-expansion warn unstable syntax can change at any point in the future, causing a hard error! 153 unsupported-calling-conventions warn use of unsupported calling convention 154 unused-allocation warn detects unnecessary allocations that can be eliminated 155 unused-assignments warn detect assignments that will never be read 156 unused-associated-type-bounds warn detects unused `Foo = Bar` bounds in `dyn Trait<Foo = Bar>` 157 unused-attributes warn detects attributes that were not used by the compiler 158 unused-braces warn unnecessary braces around an expression 159 unused-comparisons warn comparisons made useless by limits of the types involved 160 unused-doc-comments warn detects doc comments that aren't used by rustdoc 161 unused-features warn unused features found in crate-level `#[feature]` directives 162 unused-imports warn imports that are never used 163 unused-labels warn detects labels that are never used 164 unused-macros warn detects macros that were not used 165 unused-must-use warn unused result of a type flagged as `#[must_use]` 166 unused-mut warn detect mut variables which don't need to be mutable 167 unused-parens warn `if`, `match`, `while` and `return` do not need parentheses 168 unused-unsafe warn unnecessary use of an `unsafe` block 169 unused-variables warn detect variables which are not used in any way 170 useless-ptr-null-checks warn useless checking of non-null-typed pointer 171 warnings warn mass-change the level for lints which produce warnings 172 wasm-c-abi warn detects dependencies that are incompatible with the Wasm C ABI 173 where-clauses-object-safety warn checks the object safety of where clauses 174 while-true warn suggest using `loop { }` instead of `while true { }` 175 writes-through-immutable-pointer warn shared references are immutable, and pointers derived from them must not be written to 176 ambiguous-associated-items deny ambiguous associated items 177 arithmetic-overflow deny arithmetic operation overflows 178 bindings-with-variant-name deny detects pattern bindings with the same name as one of the matched variants 179 cenum-impl-drop-cast deny a C-like enum implementing Drop is cast 180 conflicting-repr-hints deny conflicts between `#[repr(..)]` hints that were previously accepted and used in practice 181 deprecated-cfg-attr-crate-type-name deny detects usage of `#![cfg_attr(..., crate_type/crate_name = "...")]` 182 enum-intrinsics-non-enums deny detects calls to `core::mem::discriminant` and `core::mem::variant_count` with non-enum types 183 ill-formed-attribute-input deny ill-formed attribute inputs that were previously accepted and used in practice 184 incomplete-include deny trailing content in included file 185 ineffective-unstable-trait-impl deny detects `#[unstable]` on stable trait implementations for stable types 186 invalid-atomic-ordering deny usage of invalid atomic ordering in atomic operations and memory fences 187 invalid-doc-attributes deny detects invalid `#[doc(...)]` attributes 188 invalid-from-utf8-unchecked deny using a non UTF-8 literal in `std::str::from_utf8_unchecked` 189 invalid-reference-casting deny casts of `&T` to `&mut T` without interior mutability 190 invalid-type-param-default deny type parameter default erroneously allowed in invalid location 191 let-underscore-lock deny non-binding let on a synchronization lock 192 long-running-const-eval deny detects long const eval operations 193 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 194 missing-fragment-specifier deny detects missing fragment specifiers in unused `macro_rules!` patterns 195 mutable-transmutes deny transmuting &T to &mut T is undefined behavior, even if the reference is unused 196 named-asm-labels deny named labels in inline assembly 197 no-mangle-const-items deny const items will not have their symbols exported 198 order-dependent-trait-objects deny trait-object types were treated as different depending on marker-trait order 199 overflowing-literals deny literal out of range for its type 200 patterns-in-fns-without-body deny patterns in functions without body were erroneously allowed 201 proc-macro-back-compat deny detects usage of old versions of certain proc-macro crates 202 proc-macro-derive-resolution-fallback deny detects proc macro derives using inaccessible names from parent modules 203 pub-use-of-private-extern-crate deny detect public re-exports of private extern crates 204 soft-unstable deny a feature gate that doesn't break dependent crates 205 test-unstable-lint deny this unstable lint is only for testing 206 text-direction-codepoint-in-comment deny invisible directionality-changing codepoints in comment 207 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 208 unconditional-panic deny operation will cause a panic at runtime 209 undropped-manually-drops deny calls to `std::mem::drop` with `std::mem::ManuallyDrop` instead of it's inner value 210 unknown-crate-types deny unknown crate type found in `#[crate_type]` directive 211 useless-deprecated deny detects deprecation attributes with no effect 212 213 214 Lint groups provided by rustc: 215 216 name sub-lints 217 ---- --------- 218 warnings all lints that are set to issue warnings 219 future-incompatible deref-into-dyn-supertrait, ambiguous-associated-items, ambiguous-glob-imports, byte-slice-in-packed-struct-with-derive, cenum-impl-drop-cast, coherence-leak-check, conflicting-repr-hints, const-eval-mutable-ptr-in-final-value, const-evaluatable-unchecked, deprecated-cfg-attr-crate-type-name, elided-lifetimes-in-associated-constant, forbidden-lint-groups, ill-formed-attribute-input, indirect-structural-match, invalid-type-param-default, late-bound-lifetime-arguments, legacy-derive-helpers, macro-expanded-macro-exports-accessed-by-absolute-paths, missing-fragment-specifier, order-dependent-trait-objects, patterns-in-fns-without-body, pointer-structural-match, proc-macro-back-compat, proc-macro-derive-resolution-fallback, pub-use-of-private-extern-crate, repr-transparent-external-private-fields, semicolon-in-expressions-from-macros, soft-unstable, uninhabited-static, unstable-name-collisions, unstable-syntax-pre-expansion, unsupported-calling-conventions, wasm-c-abi, where-clauses-object-safety, writes-through-immutable-pointer 220 keyword-idents keyword-idents-2018, keyword-idents-2024 221 let-underscore let-underscore-drop, let-underscore-lock 222 nonstandard-style non-camel-case-types, non-snake-case, non-upper-case-globals 223 refining-impl-trait refining-impl-trait-reachable, refining-impl-trait-internal 224 rust-2018-compatibility keyword-idents-2018, anonymous-parameters, absolute-paths-not-starting-with-crate, tyvar-behind-raw-pointer 225 rust-2018-idioms bare-trait-objects, unused-extern-crates, ellipsis-inclusive-range-patterns, elided-lifetimes-in-paths, explicit-outlives-requirements 226 rust-2021-compatibility ellipsis-inclusive-range-patterns, bare-trait-objects, rust-2021-incompatible-closure-captures, rust-2021-incompatible-or-patterns, rust-2021-prefixes-incompatible-syntax, rust-2021-prelude-collisions, array-into-iter, non-fmt-panics 227 rust-2024-compatibility keyword-idents-2024, static-mut-refs, unsafe-op-in-unsafe-fn 228 unused unused-imports, unused-variables, 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 229 230 231 Lint tools like Clippy can load additional lints and lint groups.