1.27.1.txt (10039B)
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 bare-trait-objects allow suggest using `dyn Trait` for trait objects 16 box-pointers allow use of owned (Box type) heap memory 17 elided-lifetimes-in-paths allow hidden lifetime parameters are deprecated, try `Foo<'_>` 18 missing-copy-implementations allow detects potentially-forgotten implementations of `Copy` 19 missing-debug-implementations allow detects missing implementations of fmt::Debug 20 missing-docs allow detects missing documentation for public members 21 single-use-lifetimes allow detects single use lifetimes 22 trivial-casts allow detects trivial casts which could be removed 23 trivial-numeric-casts allow detects trivial casts of numeric types which could be removed 24 unreachable-pub allow `pub` items not reachable from crate root 25 unsafe-code allow usage of `unsafe` code 26 unstable-features allow enabling unstable features (deprecated. do not use) 27 unused-extern-crates allow extern crates that are never used 28 unused-import-braces allow unnecessary braces around an imported item 29 unused-qualifications allow detects unnecessarily qualified names 30 unused-results allow unused result of an expression in a statement 31 variant-size-differences allow detects enums with widely varying variant sizes 32 const-err warn constant evaluation detected erroneous expression 33 dead-code warn detect unused, unexported items 34 deprecated warn detects use of deprecated items 35 illegal-floating-point-literal-pattern warn floating-point literals cannot be used in patterns 36 improper-ctypes warn proper use of libc types in foreign modules 37 incoherent-fundamental-impls warn potentially-conflicting impls were erroneously allowed 38 late-bound-lifetime-arguments warn detects generic lifetime arguments in path segments with late bound lifetime parameters 39 non-camel-case-types warn types, variants, traits and type parameters should have camel case names 40 non-shorthand-field-patterns warn using `Struct { x: x }` instead of `Struct { x }` in a pattern 41 non-snake-case warn variables, methods, functions, lifetime parameters and modules should have snake case names 42 non-upper-case-globals warn static constants should have uppercase identifiers 43 no-mangle-generic-items warn generic items must be mangled 44 overflowing-literals warn literal out of range for its type 45 path-statements warn path statements with no effect 46 patterns-in-fns-without-body warn patterns in functions without body were erroneously allowed 47 plugin-as-library warn compiler plugin used as ordinary library in non-plugin crate 48 private-in-public warn detect private items in public interfaces not caught by the old implementation 49 private-no-mangle-fns warn functions marked #[no_mangle] should be exported 50 private-no-mangle-statics warn statics marked #[no_mangle] should be exported 51 renamed-and-removed-lints warn lints that have been renamed or removed 52 safe-packed-borrows warn safe borrows of fields of packed structs were was erroneously allowed 53 stable-features warn stable features found in #[feature] directive 54 type-alias-bounds warn bounds in type aliases are not enforced 55 tyvar-behind-raw-pointer warn raw pointer to an inference variable 56 unconditional-recursion warn functions that cannot return without calling themselves 57 unions-with-drop-fields warn use of unions that contain fields with possibly non-trivial drop code 58 unknown-lints warn unrecognized lint attribute 59 unreachable-code warn detects unreachable code paths 60 unreachable-patterns warn detects unreachable patterns 61 unstable-name-collisions warn detects name collision with an existing but unstable method 62 unused-allocation warn detects unnecessary allocations that can be eliminated 63 unused-assignments warn detect assignments that will never be read 64 unused-attributes warn detects attributes that were not used by the compiler 65 unused-comparisons warn comparisons made useless by limits of the types involved 66 unused-doc-comments warn detects doc comments that aren't used by rustdoc 67 unused-features warn unused or unknown features found in crate-level #[feature] directives 68 unused-imports warn imports that are never used 69 unused-macros warn detects macros that were not used 70 unused-must-use warn unused result of a type flagged as #[must_use] 71 unused-mut warn detect mut variables which don't need to be mutable 72 unused-parens warn `if`, `match`, `while` and `return` do not need parentheses 73 unused-unsafe warn unnecessary use of an `unsafe` block 74 unused-variables warn detect variables which are not used in any way 75 warnings warn mass-change the level for lints which produce warnings 76 while-true warn suggest using `loop { }` instead of `while true { }` 77 exceeding-bitshifts deny shift exceeds the type's number of bits 78 invalid-type-param-default deny type parameter default erroneously allowed in invalid location 79 legacy-constructor-visibility deny detects use of struct constructors that would be invisible with new visibility rules 80 legacy-directory-ownership deny non-inline, non-`#[path]` modules (e.g. `mod foo;`) were erroneously allowed in some files not named `mod.rs` 81 legacy-imports deny detects names that resolve to ambiguous glob imports with RFC 1560 82 missing-fragment-specifier deny detects missing fragment specifiers in unused `macro_rules!` patterns 83 mutable-transmutes deny mutating transmuted &mut T from &T may cause undefined behavior 84 no-mangle-const-items deny const items will not have their symbols exported 85 parenthesized-params-in-types-and-modules deny detects parenthesized generic parameters in type and module names 86 pub-use-of-private-extern-crate deny detect public re-exports of private extern crates 87 safe-extern-statics deny safe access to extern statics was erroneously allowed 88 unknown-crate-types deny unknown crate type found in #[crate_type] directive 89 90 91 Lint groups provided by rustc: 92 93 name sub-lints 94 ---- --------- 95 warnings all lints that are set to issue warnings 96 bad-style non-camel-case-types, non-snake-case, non-upper-case-globals 97 future-incompatible private-in-public, pub-use-of-private-extern-crate, patterns-in-fns-without-body, safe-extern-statics, invalid-type-param-default, legacy-directory-ownership, legacy-imports, 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, incoherent-fundamental-impls, tyvar-behind-raw-pointer, unstable-name-collisions, absolute-paths-not-starting-with-crate 98 nonstandard-style non-camel-case-types, non-snake-case, non-upper-case-globals 99 rust-2018-breakage tyvar-behind-raw-pointer, absolute-paths-not-starting-with-crate 100 rust-2018-migration bare-trait-objects, unreachable-pub 101 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-parens 102 103 104 Compiler plugins can provide additional lints and lint groups. To see a listing of these, re-run `rustc -W help` with a crate filename.