1.71.1.txt (24934B)
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 elided-lifetimes-in-paths allow hidden lifetime parameters in types are deprecated 17 explicit-outlives-requirements allow outlives requirements can be inferred 18 ffi-unwind-calls allow call to foreign functions or function pointers with FFI-unwind ABI 19 fuzzy-provenance-casts allow a fuzzy integer to pointer cast is used 20 keyword-idents allow detects edition keywords being used as an identifier 21 let-underscore-drop allow non-binding let on a type that implements `Drop` 22 lossy-provenance-casts allow a lossy pointer to integer cast is used 23 macro-use-extern-crate allow the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system 24 meta-variable-misuse allow possible meta-variable misuse at macro definition 25 missing-abi allow No declared ABI for extern declaration 26 missing-copy-implementations allow detects potentially-forgotten implementations of `Copy` 27 missing-debug-implementations allow detects missing implementations of Debug 28 missing-docs allow detects missing documentation for public members 29 multiple-supertrait-upcastable allow detect when an object-safe trait has multiple supertraits 30 must-not-suspend allow use of a `#[must_not_suspend]` value across a yield point 31 non-ascii-idents allow detects non-ASCII identifiers 32 non-exhaustive-omitted-patterns allow detect when patterns of types marked `non_exhaustive` are missed 33 noop-method-call allow detects the use of well-known noop methods 34 pointer-structural-match allow pointers are not structural-match 35 rust-2021-incompatible-closure-captures allow detects closures affected by Rust 2021 changes 36 rust-2021-incompatible-or-patterns allow detects usage of old versions of or-patterns 37 rust-2021-prefixes-incompatible-syntax allow identifiers that will be parsed as a prefix in Rust 2021 38 rust-2021-prelude-collisions allow detects the usage of trait methods which are ambiguous with traits added to the prelude in future editions 39 single-use-lifetimes allow detects lifetime parameters that are only used once 40 trivial-casts allow detects trivial casts which could be removed 41 trivial-numeric-casts allow detects trivial casts of numeric types which could be removed 42 unreachable-pub allow `pub` items not reachable from crate root 43 unsafe-code allow usage of `unsafe` code 44 unsafe-op-in-unsafe-fn allow unsafe operations in unsafe functions without an explicit unsafe block are deprecated 45 unstable-features allow enabling unstable features (deprecated. do not use) 46 unused-crate-dependencies allow crate dependencies that are never used 47 unused-extern-crates allow extern crates that are never used 48 unused-import-braces allow unnecessary braces around an imported item 49 unused-lifetimes allow detects lifetime parameters that are never used 50 unused-macro-rules allow detects macro rules that were not used 51 unused-qualifications allow detects unnecessarily qualified names 52 unused-results allow unused result of an expression in a statement 53 unused-tuple-struct-fields allow detects tuple struct fields that are never read 54 variant-size-differences allow detects enums with widely varying variant sizes 55 ambiguous-glob-reexports warn ambiguous glob re-exports 56 anonymous-parameters warn detects anonymous parameters 57 array-into-iter warn detects calling `into_iter` on arrays in Rust 2015 and 2018 58 asm-sub-register warn using only a subset of a register for inline asm inputs 59 bad-asm-style warn incorrect use of inline assembly 60 bare-trait-objects warn suggest using `dyn Trait` for trait objects 61 break-with-label-and-loop warn `break` expression with label and unlabeled loop as value expression 62 byte-slice-in-packed-struct-with-derive warn `[u8]` or `str` used in a packed struct with `derive` 63 clashing-extern-declarations warn detects when an extern fn has been declared with the same name but different types 64 coherence-leak-check warn distinct impls distinguished only by the leak-check code 65 confusable-idents warn detects visually confusable pairs between identifiers 66 const-evaluatable-unchecked warn detects a generic constant is used in a type without a emitting a warning 67 const-item-mutation warn detects attempts to mutate a `const` item 68 dead-code warn detect unused, unexported items 69 deprecated warn detects use of deprecated items 70 deprecated-where-clause-location warn deprecated where clause location 71 deref-into-dyn-supertrait warn `Deref` implementation usage with a supertrait trait object for output might be shadowed in the future 72 deref-nullptr warn detects when an null pointer is dereferenced 73 dropping-copy-types warn calls to `std::mem::drop` with a value that implements Copy 74 dropping-references warn calls to `std::mem::drop` with a reference instead of an owned value 75 drop-bounds warn bounds of the form `T: Drop` are most likely incorrect 76 duplicate-macro-attributes warn duplicated attribute 77 dyn-drop warn trait objects of the form `dyn Drop` are useless 78 ellipsis-inclusive-range-patterns warn `...` range patterns are deprecated 79 exported-private-dependencies warn public interface leaks type from a private dependency 80 forbidden-lint-groups warn applying forbid to lint-groups 81 forgetting-copy-types warn calls to `std::mem::forget` with a value that implements Copy 82 forgetting-references warn calls to `std::mem::forget` with a reference instead of an owned value 83 for-loops-over-fallibles warn for-looping over an `Option` or a `Result`, which is more clearly expressed as an `if let` 84 function-item-references warn suggest casting to a function pointer when attempting to take references to function items 85 illegal-floating-point-literal-pattern warn floating-point literals cannot be used in patterns 86 improper-ctypes warn proper use of libc types in foreign modules 87 improper-ctypes-definitions warn proper use of libc types in foreign item definitions 88 incomplete-features warn incomplete features that may function improperly in some or all cases 89 indirect-structural-match warn constant used in pattern contains value of non-structural-match type in a field or a variant 90 inline-no-sanitize warn detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]` 91 invalid-doc-attributes warn detects invalid `#[doc(...)]` attributes 92 invalid-macro-export-arguments warn "invalid_parameter" isn't a valid argument for `#[macro_export]` 93 invalid-value warn an invalid value is being created (such as a null reference) 94 irrefutable-let-patterns warn detects irrefutable patterns in `if let` and `while let` statements 95 large-assignments warn detects large moves or copies 96 late-bound-lifetime-arguments warn detects generic lifetime arguments in path segments with late bound lifetime parameters 97 legacy-derive-helpers warn detects derive helper attributes that are used before they are introduced 98 map-unit-fn warn `Iterator::map` call that discard the iterator's values 99 mixed-script-confusables warn detects Unicode scripts whose mixed script confusables codepoints are solely used 100 named-arguments-used-positionally warn named arguments in format used positionally 101 nontrivial-structural-match warn constant used in pattern of non-structural-match type and the constant's initializer expression contains values of non-structural-match types 102 non-camel-case-types warn types, variants, traits and type parameters should have camel case names 103 non-fmt-panics warn detect single-argument panic!() invocations in which the argument is not a format string 104 non-shorthand-field-patterns warn using `Struct { x: x }` instead of `Struct { x }` in a pattern 105 non-snake-case warn variables, methods, functions, lifetime parameters and modules should have snake case names 106 non-upper-case-globals warn static constants should have uppercase identifiers 107 no-mangle-generic-items warn generic items must be mangled 108 opaque-hidden-inferred-bound warn detects the use of nested `impl Trait` types in associated type bounds that are not general enough 109 overlapping-range-endpoints warn detects range patterns with overlapping endpoints 110 path-statements warn path statements with no effect 111 private-in-public warn detect private items in public interfaces not caught by the old implementation 112 redundant-semicolons warn detects unnecessary trailing semicolons 113 renamed-and-removed-lints warn lints that have been renamed or removed 114 repr-transparent-external-private-fields warn transparent type contains an external ZST that is marked #[non_exhaustive] or contains private fields 115 semicolon-in-expressions-from-macros warn trailing semicolon in macro body used as expression 116 special-module-name warn module declarations for files with a special meaning 117 stable-features warn stable features found in `#[feature]` directive 118 suspicious-auto-trait-impls warn the rules governing auto traits will change in the future 119 suspicious-double-ref-op warn suspicious call of trait method on `&&T` 120 temporary-cstring-as-ptr warn detects getting the inner pointer of a temporary `CString` 121 trivial-bounds warn these bounds don't depend on an type parameters 122 type-alias-bounds warn bounds in type aliases are not enforced 123 tyvar-behind-raw-pointer warn raw pointer to an inference variable 124 uncommon-codepoints warn detects uncommon Unicode codepoints in identifiers 125 unconditional-recursion warn functions that cannot return without calling themselves 126 undefined-naked-function-abi warn undefined naked function ABI 127 unexpected-cfgs warn detects unexpected names and values in `#[cfg]` conditions 128 unfulfilled-lint-expectations warn unfulfilled lint expectation 129 ungated-async-fn-track-caller warn enabling track_caller on an async fn is a no-op unless the closure_track_caller feature is enabled 130 uninhabited-static warn uninhabited static 131 unknown-lints warn unrecognized lint attribute 132 unnameable-test-items warn detects an item that cannot be named being marked as `#[test_case]` 133 unreachable-code warn detects unreachable code paths 134 unreachable-patterns warn detects unreachable patterns 135 unstable-name-collisions warn detects name collision with an existing but unstable method 136 unstable-syntax-pre-expansion warn unstable syntax can change at any point in the future, causing a hard error! 137 unsupported-calling-conventions warn use of unsupported calling convention 138 unused-allocation warn detects unnecessary allocations that can be eliminated 139 unused-assignments warn detect assignments that will never be read 140 unused-attributes warn detects attributes that were not used by the compiler 141 unused-braces warn unnecessary braces around an expression 142 unused-comparisons warn comparisons made useless by limits of the types involved 143 unused-doc-comments warn detects doc comments that aren't used by rustdoc 144 unused-features warn unused features found in crate-level `#[feature]` directives 145 unused-imports warn imports that are never used 146 unused-labels warn detects labels that are never used 147 unused-macros warn detects macros that were not used 148 unused-must-use warn unused result of a type flagged as `#[must_use]` 149 unused-mut warn detect mut variables which don't need to be mutable 150 unused-parens warn `if`, `match`, `while` and `return` do not need parentheses 151 unused-unsafe warn unnecessary use of an `unsafe` block 152 unused-variables warn detect variables which are not used in any way 153 warnings warn mass-change the level for lints which produce warnings 154 where-clauses-object-safety warn checks the object safety of where clauses 155 while-true warn suggest using `loop { }` instead of `while true { }` 156 ambiguous-associated-items deny ambiguous associated items 157 arithmetic-overflow deny arithmetic operation overflows 158 bindings-with-variant-name deny detects pattern bindings with the same name as one of the matched variants 159 cenum-impl-drop-cast deny a C-like enum implementing Drop is cast 160 conflicting-repr-hints deny conflicts between `#[repr(..)]` hints that were previously accepted and used in practice 161 deprecated-cfg-attr-crate-type-name deny detects usage of `#![cfg_attr(..., crate_type/crate_name = "...")]` 162 enum-intrinsics-non-enums deny detects calls to `core::mem::discriminant` and `core::mem::variant_count` with non-enum types 163 ill-formed-attribute-input deny ill-formed attribute inputs that were previously accepted and used in practice 164 implied-bounds-entailment deny impl method assumes more implied bounds than its corresponding trait method 165 incomplete-include deny trailing content in included file 166 ineffective-unstable-trait-impl deny detects `#[unstable]` on stable trait implementations for stable types 167 invalid-alignment deny raw pointers must be aligned before dereferencing 168 invalid-atomic-ordering deny usage of invalid atomic ordering in atomic operations and memory fences 169 invalid-type-param-default deny type parameter default erroneously allowed in invalid location 170 let-underscore-lock deny non-binding let on a synchronization lock 171 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 172 missing-fragment-specifier deny detects missing fragment specifiers in unused `macro_rules!` patterns 173 mutable-transmutes deny transmuting &T to &mut T is undefined behavior, even if the reference is unused 174 named-asm-labels deny named labels in inline assembly 175 no-mangle-const-items deny const items will not have their symbols exported 176 order-dependent-trait-objects deny trait-object types were treated as different depending on marker-trait order 177 overflowing-literals deny literal out of range for its type 178 patterns-in-fns-without-body deny patterns in functions without body were erroneously allowed 179 proc-macro-back-compat deny detects usage of old versions of certain proc-macro crates 180 proc-macro-derive-resolution-fallback deny detects proc macro derives using inaccessible names from parent modules 181 pub-use-of-private-extern-crate deny detect public re-exports of private extern crates 182 soft-unstable deny a feature gate that doesn't break dependent crates 183 test-unstable-lint deny this unstable lint is only for testing 184 text-direction-codepoint-in-comment deny invisible directionality-changing codepoints in comment 185 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 186 unconditional-panic deny operation will cause a panic at runtime 187 unknown-crate-types deny unknown crate type found in `#[crate_type]` directive 188 useless-deprecated deny detects deprecation attributes with no effect 189 190 191 Lint groups provided by rustc: 192 193 name sub-lints 194 ---- --------- 195 warnings all lints that are set to issue warnings 196 future-incompatible deref-into-dyn-supertrait, ambiguous-associated-items, byte-slice-in-packed-struct-with-derive, cenum-impl-drop-cast, coherence-leak-check, conflicting-repr-hints, const-evaluatable-unchecked, deprecated-cfg-attr-crate-type-name, forbidden-lint-groups, ill-formed-attribute-input, illegal-floating-point-literal-pattern, implied-bounds-entailment, indirect-structural-match, invalid-alignment, invalid-doc-attributes, invalid-type-param-default, late-bound-lifetime-arguments, legacy-derive-helpers, macro-expanded-macro-exports-accessed-by-absolute-paths, missing-fragment-specifier, nontrivial-structural-match, order-dependent-trait-objects, patterns-in-fns-without-body, pointer-structural-match, private-in-public, 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, suspicious-auto-trait-impls, uninhabited-static, unstable-name-collisions, unstable-syntax-pre-expansion, unsupported-calling-conventions, where-clauses-object-safety 197 let-underscore let-underscore-drop, let-underscore-lock 198 nonstandard-style non-camel-case-types, non-snake-case, non-upper-case-globals 199 rust-2018-compatibility keyword-idents, anonymous-parameters, absolute-paths-not-starting-with-crate, tyvar-behind-raw-pointer 200 rust-2018-idioms bare-trait-objects, unused-extern-crates, ellipsis-inclusive-range-patterns, elided-lifetimes-in-paths, explicit-outlives-requirements 201 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 202 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 203 204 205 Lint tools like Clippy can provide additional lints and lint groups.