1.58.0.txt (20894B)
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 keyword-idents allow detects edition keywords being used as an identifier 19 macro-use-extern-crate allow the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system 20 meta-variable-misuse allow possible meta-variable misuse at macro definition 21 missing-abi allow No declared ABI for extern declaration 22 missing-copy-implementations allow detects potentially-forgotten implementations of `Copy` 23 missing-debug-implementations allow detects missing implementations of Debug 24 missing-docs allow detects missing documentation for public members 25 must-not-suspend allow use of a `#[must_not_suspend]` value across a yield point 26 non-ascii-idents allow detects non-ASCII identifiers 27 non-exhaustive-omitted-patterns allow detect when patterns of types marked `non_exhaustive` are missed 28 noop-method-call allow detects the use of well-known noop methods 29 pointer-structural-match allow pointers are not structural-match 30 rust-2021-incompatible-closure-captures allow detects closures affected by Rust 2021 changes 31 rust-2021-incompatible-or-patterns allow detects usage of old versions of or-patterns 32 rust-2021-prefixes-incompatible-syntax allow identifiers that will be parsed as a prefix in Rust 2021 33 rust-2021-prelude-collisions allow detects the usage of trait methods which are ambiguous with traits added to the prelude in future editions 34 single-use-lifetimes allow detects lifetime parameters that are only used once 35 trivial-casts allow detects trivial casts which could be removed 36 trivial-numeric-casts allow detects trivial casts of numeric types which could be removed 37 unreachable-pub allow `pub` items not reachable from crate root 38 unsafe-code allow usage of `unsafe` code 39 unsafe-op-in-unsafe-fn allow unsafe operations in unsafe functions without an explicit unsafe block are deprecated 40 unstable-features allow enabling unstable features (deprecated. do not use) 41 unused-crate-dependencies allow crate dependencies that are never used 42 unused-extern-crates allow extern crates that are never used 43 unused-import-braces allow unnecessary braces around an imported item 44 unused-lifetimes allow detects lifetime parameters that are never used 45 unused-qualifications allow detects unnecessarily qualified names 46 unused-results allow unused result of an expression in a statement 47 variant-size-differences allow detects enums with widely varying variant sizes 48 anonymous-parameters warn detects anonymous parameters 49 array-into-iter warn detects calling `into_iter` on arrays in Rust 2015 and 2018 50 asm-sub-register warn using only a subset of a register for inline asm inputs 51 bad-asm-style warn incorrect use of inline assembly 52 bare-trait-objects warn suggest using `dyn Trait` for trait objects 53 bindings-with-variant-name warn detects pattern bindings with the same name as one of the matched variants 54 break-with-label-and-loop warn `break` expression with label and unlabeled loop as value expression 55 cenum-impl-drop-cast warn a C-like enum implementing Drop is cast 56 clashing-extern-declarations warn detects when an extern fn has been declared with the same name but different types 57 coherence-leak-check warn distinct impls distinguished only by the leak-check code 58 confusable-idents warn detects visually confusable pairs between identifiers 59 const-evaluatable-unchecked warn detects a generic constant is used in a type without a emitting a warning 60 const-item-mutation warn detects attempts to mutate a `const` item 61 dead-code warn detect unused, unexported items 62 deprecated warn detects use of deprecated items 63 deref-into-dyn-supertrait warn `Deref` implementation usage with a supertrait trait object for output might be shadowed in the future 64 deref-nullptr warn detects when an null pointer is dereferenced 65 drop-bounds warn bounds of the form `T: Drop` are most likely incorrect 66 dyn-drop warn trait objects of the form `dyn Drop` are useless 67 ellipsis-inclusive-range-patterns warn `...` range patterns are deprecated 68 exported-private-dependencies warn public interface leaks type from a private dependency 69 forbidden-lint-groups warn applying forbid to lint-groups 70 function-item-references warn suggest casting to a function pointer when attempting to take references to function items 71 illegal-floating-point-literal-pattern warn floating-point literals cannot be used in patterns 72 improper-ctypes warn proper use of libc types in foreign modules 73 improper-ctypes-definitions warn proper use of libc types in foreign item definitions 74 incomplete-features warn incomplete features that may function improperly in some or all cases 75 indirect-structural-match warn constant used in pattern contains value of non-structural-match type in a field or a variant 76 inline-no-sanitize warn detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]` 77 invalid-doc-attributes warn detects invalid `#[doc(...)]` attributes 78 invalid-value warn an invalid value is being created (such as a null reference) 79 irrefutable-let-patterns warn detects irrefutable patterns in `if let` and `while let` statements 80 large-assignments warn detects large moves or copies 81 late-bound-lifetime-arguments warn detects generic lifetime arguments in path segments with late bound lifetime parameters 82 legacy-derive-helpers warn detects derive helper attributes that are used before they are introduced 83 mixed-script-confusables warn detects Unicode scripts whose mixed script confusables codepoints are solely used 84 mutable-borrow-reservation-conflict warn reservation of a two-phased borrow conflicts with other shared borrows 85 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 86 non-camel-case-types warn types, variants, traits and type parameters should have camel case names 87 non-fmt-panics warn detect single-argument panic!() invocations in which the argument is not a format string 88 non-shorthand-field-patterns warn using `Struct { x: x }` instead of `Struct { x }` in a pattern 89 non-snake-case warn variables, methods, functions, lifetime parameters and modules should have snake case names 90 non-upper-case-globals warn static constants should have uppercase identifiers 91 no-mangle-generic-items warn generic items must be mangled 92 overlapping-range-endpoints warn detects range patterns with overlapping endpoints 93 path-statements warn path statements with no effect 94 private-in-public warn detect private items in public interfaces not caught by the old implementation 95 redundant-semicolons warn detects unnecessary trailing semicolons 96 renamed-and-removed-lints warn lints that have been renamed or removed 97 semicolon-in-expressions-from-macros warn trailing semicolon in macro body used as expression 98 stable-features warn stable features found in `#[feature]` directive 99 temporary-cstring-as-ptr warn detects getting the inner pointer of a temporary `CString` 100 trivial-bounds warn these bounds don't depend on an type parameters 101 type-alias-bounds warn bounds in type aliases are not enforced 102 tyvar-behind-raw-pointer warn raw pointer to an inference variable 103 unaligned-references warn detects unaligned references to fields of packed structs 104 uncommon-codepoints warn detects uncommon Unicode codepoints in identifiers 105 unconditional-recursion warn functions that cannot return without calling themselves 106 uninhabited-static warn uninhabited static 107 unknown-lints warn unrecognized lint attribute 108 unnameable-test-items warn detects an item that cannot be named being marked as `#[test_case]` 109 unreachable-code warn detects unreachable code paths 110 unreachable-patterns warn detects unreachable patterns 111 unstable-name-collisions warn detects name collision with an existing but unstable method 112 unsupported-calling-conventions warn use of unsupported calling convention 113 unsupported-naked-functions warn unsupported naked function definitions 114 unused-allocation warn detects unnecessary allocations that can be eliminated 115 unused-assignments warn detect assignments that will never be read 116 unused-attributes warn detects attributes that were not used by the compiler 117 unused-braces warn unnecessary braces around an expression 118 unused-comparisons warn comparisons made useless by limits of the types involved 119 unused-doc-comments warn detects doc comments that aren't used by rustdoc 120 unused-features warn unused features found in crate-level `#[feature]` directives 121 unused-imports warn imports that are never used 122 unused-labels warn detects labels that are never used 123 unused-macros warn detects macros that were not used 124 unused-must-use warn unused result of a type flagged as `#[must_use]` 125 unused-mut warn detect mut variables which don't need to be mutable 126 unused-parens warn `if`, `match`, `while` and `return` do not need parentheses 127 unused-unsafe warn unnecessary use of an `unsafe` block 128 unused-variables warn detect variables which are not used in any way 129 warnings warn mass-change the level for lints which produce warnings 130 where-clauses-object-safety warn checks the object safety of where clauses 131 while-true warn suggest using `loop { }` instead of `while true { }` 132 ambiguous-associated-items deny ambiguous associated items 133 arithmetic-overflow deny arithmetic operation overflows 134 conflicting-repr-hints deny conflicts between `#[repr(..)]` hints that were previously accepted and used in practice 135 const-err deny constant evaluation encountered erroneous expression 136 enum-intrinsics-non-enums deny detects calls to `core::mem::discriminant` and `core::mem::variant_count` with non-enum types 137 ill-formed-attribute-input deny ill-formed attribute inputs that were previously accepted and used in practice 138 incomplete-include deny trailing content in included file 139 ineffective-unstable-trait-impl deny detects `#[unstable]` on stable trait implementations for stable types 140 invalid-atomic-ordering deny usage of invalid atomic ordering in atomic operations and memory fences 141 invalid-type-param-default deny type parameter default erroneously allowed in invalid location 142 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 143 missing-fragment-specifier deny detects missing fragment specifiers in unused `macro_rules!` patterns 144 mutable-transmutes deny mutating transmuted &mut T from &T may cause undefined behavior 145 named-asm-labels deny named labels in inline assembly 146 no-mangle-const-items deny const items will not have their symbols exported 147 order-dependent-trait-objects deny trait-object types were treated as different depending on marker-trait order 148 overflowing-literals deny literal out of range for its type 149 patterns-in-fns-without-body deny patterns in functions without body were erroneously allowed 150 proc-macro-back-compat deny detects usage of old versions of certain proc-macro crates 151 proc-macro-derive-resolution-fallback deny detects proc macro derives using inaccessible names from parent modules 152 pub-use-of-private-extern-crate deny detect public re-exports of private extern crates 153 soft-unstable deny a feature gate that doesn't break dependent crates 154 text-direction-codepoint-in-comment deny invisible directionality-changing codepoints in comment 155 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 156 unconditional-panic deny operation will cause a panic at runtime 157 unknown-crate-types deny unknown crate type found in `#[crate_type]` directive 158 useless-deprecated deny detects deprecation attributes with no effect 159 160 161 Lint groups provided by rustc: 162 163 name sub-lints 164 ---- --------- 165 warnings all lints that are set to issue warnings 166 future-incompatible forbidden-lint-groups, illegal-floating-point-literal-pattern, private-in-public, pub-use-of-private-extern-crate, invalid-type-param-default, const-err, unaligned-references, patterns-in-fns-without-body, missing-fragment-specifier, late-bound-lifetime-arguments, order-dependent-trait-objects, coherence-leak-check, unstable-name-collisions, where-clauses-object-safety, proc-macro-derive-resolution-fallback, macro-expanded-macro-exports-accessed-by-absolute-paths, ill-formed-attribute-input, conflicting-repr-hints, ambiguous-associated-items, mutable-borrow-reservation-conflict, indirect-structural-match, pointer-structural-match, nontrivial-structural-match, soft-unstable, cenum-impl-drop-cast, const-evaluatable-unchecked, uninhabited-static, unsupported-naked-functions, invalid-doc-attributes, semicolon-in-expressions-from-macros, legacy-derive-helpers, proc-macro-back-compat, unsupported-calling-conventions, deref-into-dyn-supertrait 167 nonstandard-style non-camel-case-types, non-snake-case, non-upper-case-globals 168 rust-2018-compatibility keyword-idents, anonymous-parameters, tyvar-behind-raw-pointer, absolute-paths-not-starting-with-crate 169 rust-2018-idioms bare-trait-objects, unused-extern-crates, ellipsis-inclusive-range-patterns, elided-lifetimes-in-paths, explicit-outlives-requirements 170 rust-2021-compatibility ellipsis-inclusive-range-patterns, bare-trait-objects, rust-2021-incompatible-closure-captures, rust-2021-incompatible-or-patterns, rust-2021-prelude-collisions, rust-2021-prefixes-incompatible-syntax, array-into-iter, non-fmt-panics 171 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-allocation, unused-doc-comments, unused-extern-crates, unused-features, unused-labels, unused-parens, unused-braces, redundant-semicolons 172 173 174 Lint tools like Clippy can provide additional lints and lint groups.