1.39.0.txt (14995B)
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 anonymous-parameters allow detects anonymous parameters 15 box-pointers allow use of owned (Box type) heap memory 16 deprecated-in-future allow detects use of items that will be deprecated in a future version 17 elided-lifetimes-in-paths allow hidden lifetime parameters in types are deprecated 18 explicit-outlives-requirements allow outlives requirements can be inferred 19 indirect-structural-match allow pattern with const indirectly referencing non-`#[structural_match]` type 20 keyword-idents allow detects edition keywords being used as an identifier 21 macro-use-extern-crate allow the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system 22 meta-variable-misuse allow possible meta-variable misuse at macro definition 23 missing-copy-implementations allow detects potentially-forgotten implementations of `Copy` 24 missing-debug-implementations allow detects missing implementations of fmt::Debug 25 missing-docs allow detects missing documentation for public members 26 missing-doc-code-examples allow detects publicly-exported items without code samples in their documentation 27 non-ascii-idents allow detects non-ASCII identifiers 28 private-doc-tests allow detects code samples in docs of private items not documented by rustdoc 29 single-use-lifetimes allow detects lifetime parameters that are only used once 30 trivial-casts allow detects trivial casts which could be removed 31 trivial-numeric-casts allow detects trivial casts of numeric types which could be removed 32 unreachable-pub allow `pub` items not reachable from crate root 33 unsafe-code allow usage of `unsafe` code 34 unstable-features allow enabling unstable features (deprecated. do not use) 35 unused-extern-crates allow extern crates that are never used 36 unused-import-braces allow unnecessary braces around an imported item 37 unused-labels allow detects labels that are never used 38 unused-lifetimes allow detects lifetime parameters that are never used 39 unused-qualifications allow detects unnecessarily qualified names 40 unused-results allow unused result of an expression in a statement 41 variant-size-differences allow detects enums with widely varying variant sizes 42 bare-trait-objects warn suggest using `dyn Trait` for trait objects 43 dead-code warn detect unused, unexported items 44 deprecated warn detects use of deprecated items 45 ellipsis-inclusive-range-patterns warn `...` range patterns are deprecated 46 exported-private-dependencies warn public interface leaks type from a private dependency 47 illegal-floating-point-literal-pattern warn floating-point literals cannot be used in patterns 48 ill-formed-attribute-input warn ill-formed attribute inputs that were previously accepted and used in practice 49 improper-ctypes warn proper use of libc types in foreign modules 50 incomplete-features warn incomplete features that may function improperly in some or all cases 51 intra-doc-link-resolution-failure warn failures in resolving intra-doc link targets 52 invalid-value warn an invalid value is being created (such as a NULL reference) 53 irrefutable-let-patterns warn detects irrefutable patterns in if-let and while-let statements 54 late-bound-lifetime-arguments warn detects generic lifetime arguments in path segments with late bound lifetime parameters 55 mutable-borrow-reservation-conflict warn reservation of a two-phased borrow conflicts with other shared borrows 56 nested-impl-trait warn nested occurrence of `impl Trait` type 57 non-camel-case-types warn types, variants, traits and type parameters should have camel case names 58 non-shorthand-field-patterns warn using `Struct { x: x }` instead of `Struct { x }` in a pattern 59 non-snake-case warn variables, methods, functions, lifetime parameters and modules should have snake case names 60 non-upper-case-globals warn static constants should have uppercase identifiers 61 no-mangle-generic-items warn generic items must be mangled 62 path-statements warn path statements with no effect 63 patterns-in-fns-without-body warn patterns in functions without body were erroneously allowed 64 plugin-as-library warn compiler plugin used as ordinary library in non-plugin crate 65 private-in-public warn detect private items in public interfaces not caught by the old implementation 66 proc-macro-derive-resolution-fallback warn detects proc macro derives using inaccessible names from parent modules 67 redundant-semicolon warn detects unnecessary trailing semicolons 68 renamed-and-removed-lints warn lints that have been renamed or removed 69 safe-packed-borrows warn safe borrows of fields of packed structs were was erroneously allowed 70 stable-features warn stable features found in `#[feature]` directive 71 trivial-bounds warn these bounds don't depend on an type parameters 72 type-alias-bounds warn bounds in type aliases are not enforced 73 tyvar-behind-raw-pointer warn raw pointer to an inference variable 74 unconditional-recursion warn functions that cannot return without calling themselves 75 unions-with-drop-fields warn use of unions that contain fields with possibly non-trivial drop code 76 unknown-lints warn unrecognized lint attribute 77 unnameable-test-items warn detects an item that cannot be named being marked as `#[test_case]` 78 unreachable-code warn detects unreachable code paths 79 unreachable-patterns warn detects unreachable patterns 80 unstable-name-collisions warn detects name collision with an existing but unstable method 81 unused-allocation warn detects unnecessary allocations that can be eliminated 82 unused-assignments warn detect assignments that will never be read 83 unused-attributes warn detects attributes that were not used by the compiler 84 unused-comparisons warn comparisons made useless by limits of the types involved 85 unused-doc-comments warn detects doc comments that aren't used by rustdoc 86 unused-features warn unused features found in crate-level `#[feature]` directives 87 unused-imports warn imports that are never used 88 unused-macros warn detects macros that were not used 89 unused-must-use warn unused result of a type flagged as `#[must_use]` 90 unused-mut warn detect mut variables which don't need to be mutable 91 unused-parens warn `if`, `match`, `while` and `return` do not need parentheses 92 unused-unsafe warn unnecessary use of an `unsafe` block 93 unused-variables warn detect variables which are not used in any way 94 warnings warn mass-change the level for lints which produce warnings 95 where-clauses-object-safety warn checks the object safety of where clauses 96 while-true warn suggest using `loop { }` instead of `while true { }` 97 ambiguous-associated-items deny ambiguous associated items 98 const-err deny constant evaluation detected erroneous expression 99 duplicate-macro-exports deny detects duplicate macro exports 100 exceeding-bitshifts deny shift exceeds the type's number of bits 101 invalid-type-param-default deny type parameter default erroneously allowed in invalid location 102 legacy-constructor-visibility deny detects use of struct constructors that would be invisible with new visibility rules 103 legacy-directory-ownership deny non-inline, non-`#[path]` modules (e.g., `mod foo;`) were erroneously allowed in some files not named `mod.rs` 104 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 105 missing-fragment-specifier deny detects missing fragment specifiers in unused `macro_rules!` patterns 106 mutable-transmutes deny mutating transmuted &mut T from &T may cause undefined behavior 107 no-mangle-const-items deny const items will not have their symbols exported 108 order-dependent-trait-objects deny trait-object types were treated as different depending on marker-trait order 109 overflowing-literals deny literal out of range for its type 110 parenthesized-params-in-types-and-modules deny detects parenthesized generic parameters in type and module names 111 pub-use-of-private-extern-crate deny detect public re-exports of private extern crates 112 safe-extern-statics deny safe access to extern statics was erroneously allowed 113 soft-unstable deny a feature gate that doesn't break dependent crates 114 unknown-crate-types deny unknown crate type found in `#[crate_type]` directive 115 116 117 Lint groups provided by rustc: 118 119 name sub-lints 120 ---- --------- 121 warnings all lints that are set to issue warnings 122 future-incompatible private-in-public, pub-use-of-private-extern-crate, patterns-in-fns-without-body, duplicate-macro-exports, keyword-idents, safe-extern-statics, invalid-type-param-default, legacy-directory-ownership, legacy-constructor-visibility, missing-fragment-specifier, illegal-floating-point-literal-pattern, anonymous-parameters, parenthesized-params-in-types-and-modules, late-bound-lifetime-arguments, safe-packed-borrows, order-dependent-trait-objects, tyvar-behind-raw-pointer, unstable-name-collisions, absolute-paths-not-starting-with-crate, where-clauses-object-safety, proc-macro-derive-resolution-fallback, macro-expanded-macro-exports-accessed-by-absolute-paths, ill-formed-attribute-input, ambiguous-associated-items, nested-impl-trait, mutable-borrow-reservation-conflict, indirect-structural-match, soft-unstable 123 nonstandard-style non-camel-case-types, non-snake-case, non-upper-case-globals 124 rust-2018-compatibility duplicate-macro-exports, keyword-idents, anonymous-parameters, tyvar-behind-raw-pointer, absolute-paths-not-starting-with-crate 125 rust-2018-idioms bare-trait-objects, unused-extern-crates, ellipsis-inclusive-range-patterns, elided-lifetimes-in-paths, explicit-outlives-requirements 126 rustdoc intra-doc-link-resolution-failure, missing-doc-code-examples, private-doc-tests 127 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 128 129 130 Compiler plugins can provide additional lints and lint groups. To see a listing of these, re-run `rustc -W help` with a crate filename.