diff options
Diffstat (limited to 'crates')
-rw-r--r-- | crates/ide/src/hover.rs | 145 | ||||
-rw-r--r-- | crates/ide_completion/src/completions/attribute.rs | 5 | ||||
-rw-r--r-- | crates/ide_completion/src/completions/attribute/lint.rs | 127 | ||||
-rw-r--r-- | crates/ide_completion/src/lib.rs | 1 | ||||
-rw-r--r-- | crates/ide_db/src/helpers.rs | 1 | ||||
-rw-r--r-- | crates/ide_db/src/helpers/generated_lints.rs (renamed from crates/ide_completion/src/generated_lint_completions.rs) | 7168 |
6 files changed, 3991 insertions, 3456 deletions
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs index 455a27e48..ed4f18e1f 100644 --- a/crates/ide/src/hover.rs +++ b/crates/ide/src/hover.rs | |||
@@ -6,12 +6,18 @@ use hir::{ | |||
6 | use ide_db::{ | 6 | use ide_db::{ |
7 | base_db::SourceDatabase, | 7 | base_db::SourceDatabase, |
8 | defs::{Definition, NameClass, NameRefClass}, | 8 | defs::{Definition, NameClass, NameRefClass}, |
9 | helpers::FamousDefs, | 9 | helpers::{ |
10 | generated_lints::{CLIPPY_LINTS, DEFAULT_LINTS, FEATURES}, | ||
11 | FamousDefs, | ||
12 | }, | ||
10 | RootDatabase, | 13 | RootDatabase, |
11 | }; | 14 | }; |
12 | use itertools::Itertools; | 15 | use itertools::Itertools; |
13 | use stdx::format_to; | 16 | use stdx::format_to; |
14 | use syntax::{ast, match_ast, AstNode, AstToken, SyntaxKind::*, SyntaxToken, TokenAtOffset, T}; | 17 | use syntax::{ |
18 | algo, ast, match_ast, AstNode, AstToken, Direction, SyntaxKind::*, SyntaxToken, TokenAtOffset, | ||
19 | T, | ||
20 | }; | ||
15 | 21 | ||
16 | use crate::{ | 22 | use crate::{ |
17 | display::{macro_label, TryToNav}, | 23 | display::{macro_label, TryToNav}, |
@@ -118,8 +124,9 @@ pub(crate) fn hover( | |||
118 | |d| d.defined(db), | 124 | |d| d.defined(db), |
119 | ), | 125 | ), |
120 | 126 | ||
121 | _ => ast::Comment::cast(token.clone()) | 127 | _ => { |
122 | .and_then(|_| { | 128 | if ast::Comment::cast(token.clone()).is_some() { |
129 | cov_mark::hit!(no_highlight_on_comment_hover); | ||
123 | let (attributes, def) = doc_attributes(&sema, &node)?; | 130 | let (attributes, def) = doc_attributes(&sema, &node)?; |
124 | let (docs, doc_mapping) = attributes.docs_with_rangemap(db)?; | 131 | let (docs, doc_mapping) = attributes.docs_with_rangemap(db)?; |
125 | let (idl_range, link, ns) = | 132 | let (idl_range, link, ns) = |
@@ -132,9 +139,13 @@ pub(crate) fn hover( | |||
132 | } | 139 | } |
133 | })?; | 140 | })?; |
134 | range = Some(idl_range); | 141 | range = Some(idl_range); |
135 | resolve_doc_path_for_def(db, def, &link, ns) | 142 | resolve_doc_path_for_def(db, def, &link, ns).map(Definition::ModuleDef) |
136 | }) | 143 | } else if let res@Some(_) = try_hover_for_attribute(&token) { |
137 | .map(Definition::ModuleDef), | 144 | return res; |
145 | } else { | ||
146 | None | ||
147 | } | ||
148 | }, | ||
138 | } | 149 | } |
139 | }; | 150 | }; |
140 | 151 | ||
@@ -168,11 +179,6 @@ pub(crate) fn hover( | |||
168 | } | 179 | } |
169 | } | 180 | } |
170 | 181 | ||
171 | if token.kind() == syntax::SyntaxKind::COMMENT { | ||
172 | cov_mark::hit!(no_highlight_on_comment_hover); | ||
173 | return None; | ||
174 | } | ||
175 | |||
176 | if let res @ Some(_) = hover_for_keyword(&sema, links_in_hover, markdown, &token) { | 182 | if let res @ Some(_) = hover_for_keyword(&sema, links_in_hover, markdown, &token) { |
177 | return res; | 183 | return res; |
178 | } | 184 | } |
@@ -201,6 +207,51 @@ pub(crate) fn hover( | |||
201 | Some(RangeInfo::new(range, res)) | 207 | Some(RangeInfo::new(range, res)) |
202 | } | 208 | } |
203 | 209 | ||
210 | fn try_hover_for_attribute(token: &SyntaxToken) -> Option<RangeInfo<HoverResult>> { | ||
211 | let attr = token.ancestors().nth(1).and_then(ast::Attr::cast)?; | ||
212 | let (path, tt) = attr.as_simple_call()?; | ||
213 | if !tt.syntax().text_range().contains(token.text_range().start()) { | ||
214 | return None; | ||
215 | } | ||
216 | let (is_clippy, lints) = match &*path { | ||
217 | "feature" => (false, FEATURES), | ||
218 | "allow" | "deny" | "forbid" | "warn" => { | ||
219 | let is_clippy = algo::non_trivia_sibling(token.clone().into(), Direction::Prev) | ||
220 | .filter(|t| t.kind() == T![:]) | ||
221 | .and_then(|t| algo::non_trivia_sibling(t, Direction::Prev)) | ||
222 | .filter(|t| t.kind() == T![:]) | ||
223 | .and_then(|t| algo::non_trivia_sibling(t, Direction::Prev)) | ||
224 | .map_or(false, |t| { | ||
225 | t.kind() == T![ident] && t.into_token().map_or(false, |t| t.text() == "clippy") | ||
226 | }); | ||
227 | if is_clippy { | ||
228 | (true, CLIPPY_LINTS) | ||
229 | } else { | ||
230 | (false, DEFAULT_LINTS) | ||
231 | } | ||
232 | } | ||
233 | _ => return None, | ||
234 | }; | ||
235 | |||
236 | let tmp; | ||
237 | let needle = if is_clippy { | ||
238 | tmp = format!("clippy::{}", token.text()); | ||
239 | &tmp | ||
240 | } else { | ||
241 | &*token.text() | ||
242 | }; | ||
243 | |||
244 | let lint = | ||
245 | lints.binary_search_by_key(&needle, |lint| lint.label).ok().map(|idx| &lints[idx])?; | ||
246 | Some(RangeInfo::new( | ||
247 | token.text_range(), | ||
248 | HoverResult { | ||
249 | markup: Markup::from(format!("```\n{}\n```\n___\n\n{}", lint.label, lint.description)), | ||
250 | ..Default::default() | ||
251 | }, | ||
252 | )) | ||
253 | } | ||
254 | |||
204 | fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> { | 255 | fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> { |
205 | fn to_action(nav_target: NavigationTarget) -> HoverAction { | 256 | fn to_action(nav_target: NavigationTarget) -> HoverAction { |
206 | HoverAction::Implementation(FilePosition { | 257 | HoverAction::Implementation(FilePosition { |
@@ -4004,4 +4055,74 @@ pub fn foo() {} | |||
4004 | "#]], | 4055 | "#]], |
4005 | ) | 4056 | ) |
4006 | } | 4057 | } |
4058 | |||
4059 | #[test] | ||
4060 | fn hover_feature() { | ||
4061 | check( | ||
4062 | r#"#![feature(box_syntax$0)]"#, | ||
4063 | expect![[r##" | ||
4064 | *box_syntax* | ||
4065 | ``` | ||
4066 | box_syntax | ||
4067 | ``` | ||
4068 | ___ | ||
4069 | |||
4070 | # `box_syntax` | ||
4071 | |||
4072 | The tracking issue for this feature is: [#49733] | ||
4073 | |||
4074 | [#49733]: https://github.com/rust-lang/rust/issues/49733 | ||
4075 | |||
4076 | See also [`box_patterns`](box-patterns.md) | ||
4077 | |||
4078 | ------------------------ | ||
4079 | |||
4080 | Currently the only stable way to create a `Box` is via the `Box::new` method. | ||
4081 | Also it is not possible in stable Rust to destructure a `Box` in a match | ||
4082 | pattern. The unstable `box` keyword can be used to create a `Box`. An example | ||
4083 | usage would be: | ||
4084 | |||
4085 | ```rust | ||
4086 | #![feature(box_syntax)] | ||
4087 | |||
4088 | fn main() { | ||
4089 | let b = box 5; | ||
4090 | } | ||
4091 | ``` | ||
4092 | |||
4093 | "##]], | ||
4094 | ) | ||
4095 | } | ||
4096 | |||
4097 | #[test] | ||
4098 | fn hover_lint() { | ||
4099 | check( | ||
4100 | r#"#![allow(arithmetic_overflow$0)]"#, | ||
4101 | expect![[r#" | ||
4102 | *arithmetic_overflow* | ||
4103 | ``` | ||
4104 | arithmetic_overflow | ||
4105 | ``` | ||
4106 | ___ | ||
4107 | |||
4108 | arithmetic operation overflows | ||
4109 | "#]], | ||
4110 | ) | ||
4111 | } | ||
4112 | |||
4113 | #[test] | ||
4114 | fn hover_clippy_lint() { | ||
4115 | check( | ||
4116 | r#"#![allow(clippy::almost_swapped$0)]"#, | ||
4117 | expect![[r#" | ||
4118 | *almost_swapped* | ||
4119 | ``` | ||
4120 | clippy::almost_swapped | ||
4121 | ``` | ||
4122 | ___ | ||
4123 | |||
4124 | Checks for `foo = bar; bar = foo` sequences. | ||
4125 | "#]], | ||
4126 | ) | ||
4127 | } | ||
4007 | } | 4128 | } |
diff --git a/crates/ide_completion/src/completions/attribute.rs b/crates/ide_completion/src/completions/attribute.rs index c48bb9e66..f80d7eec3 100644 --- a/crates/ide_completion/src/completions/attribute.rs +++ b/crates/ide_completion/src/completions/attribute.rs | |||
@@ -3,20 +3,19 @@ | |||
3 | //! This module uses a bit of static metadata to provide completions | 3 | //! This module uses a bit of static metadata to provide completions |
4 | //! for built-in attributes. | 4 | //! for built-in attributes. |
5 | 5 | ||
6 | use ide_db::helpers::generated_lints::{CLIPPY_LINTS, DEFAULT_LINTS, FEATURES}; | ||
6 | use once_cell::sync::Lazy; | 7 | use once_cell::sync::Lazy; |
7 | use rustc_hash::{FxHashMap, FxHashSet}; | 8 | use rustc_hash::{FxHashMap, FxHashSet}; |
8 | use syntax::{algo::non_trivia_sibling, ast, AstNode, Direction, NodeOrToken, SyntaxKind, T}; | 9 | use syntax::{algo::non_trivia_sibling, ast, AstNode, Direction, NodeOrToken, SyntaxKind, T}; |
9 | 10 | ||
10 | use crate::{ | 11 | use crate::{ |
11 | context::CompletionContext, | 12 | context::CompletionContext, |
12 | generated_lint_completions::{CLIPPY_LINTS, FEATURES}, | ||
13 | item::{CompletionItem, CompletionItemKind, CompletionKind}, | 13 | item::{CompletionItem, CompletionItemKind, CompletionKind}, |
14 | Completions, | 14 | Completions, |
15 | }; | 15 | }; |
16 | 16 | ||
17 | mod derive; | 17 | mod derive; |
18 | mod lint; | 18 | mod lint; |
19 | pub(crate) use self::lint::LintCompletion; | ||
20 | 19 | ||
21 | pub(crate) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> { | 20 | pub(crate) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) -> Option<()> { |
22 | let attribute = ctx.attribute_under_caret.as_ref()?; | 21 | let attribute = ctx.attribute_under_caret.as_ref()?; |
@@ -25,7 +24,7 @@ pub(crate) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext) | |||
25 | "derive" => derive::complete_derive(acc, ctx, token_tree), | 24 | "derive" => derive::complete_derive(acc, ctx, token_tree), |
26 | "feature" => lint::complete_lint(acc, ctx, token_tree, FEATURES), | 25 | "feature" => lint::complete_lint(acc, ctx, token_tree, FEATURES), |
27 | "allow" | "warn" | "deny" | "forbid" => { | 26 | "allow" | "warn" | "deny" | "forbid" => { |
28 | lint::complete_lint(acc, ctx, token_tree.clone(), lint::DEFAULT_LINT_COMPLETIONS); | 27 | lint::complete_lint(acc, ctx, token_tree.clone(), DEFAULT_LINTS); |
29 | lint::complete_lint(acc, ctx, token_tree, CLIPPY_LINTS); | 28 | lint::complete_lint(acc, ctx, token_tree, CLIPPY_LINTS); |
30 | } | 29 | } |
31 | _ => (), | 30 | _ => (), |
diff --git a/crates/ide_completion/src/completions/attribute/lint.rs b/crates/ide_completion/src/completions/attribute/lint.rs index 403630dce..b486c9093 100644 --- a/crates/ide_completion/src/completions/attribute/lint.rs +++ b/crates/ide_completion/src/completions/attribute/lint.rs | |||
@@ -1,4 +1,5 @@ | |||
1 | //! Completion for lints | 1 | //! Completion for lints |
2 | use ide_db::helpers::generated_lints::Lint; | ||
2 | use syntax::ast; | 3 | use syntax::ast; |
3 | 4 | ||
4 | use crate::{ | 5 | use crate::{ |
@@ -11,7 +12,7 @@ pub(super) fn complete_lint( | |||
11 | acc: &mut Completions, | 12 | acc: &mut Completions, |
12 | ctx: &CompletionContext, | 13 | ctx: &CompletionContext, |
13 | derive_input: ast::TokenTree, | 14 | derive_input: ast::TokenTree, |
14 | lints_completions: &[LintCompletion], | 15 | lints_completions: &[Lint], |
15 | ) { | 16 | ) { |
16 | if let Some(existing_lints) = super::parse_comma_sep_input(derive_input) { | 17 | if let Some(existing_lints) = super::parse_comma_sep_input(derive_input) { |
17 | for lint_completion in lints_completions | 18 | for lint_completion in lints_completions |
@@ -29,130 +30,6 @@ pub(super) fn complete_lint( | |||
29 | } | 30 | } |
30 | } | 31 | } |
31 | 32 | ||
32 | pub(crate) struct LintCompletion { | ||
33 | pub(crate) label: &'static str, | ||
34 | pub(crate) description: &'static str, | ||
35 | } | ||
36 | |||
37 | #[rustfmt::skip] | ||
38 | pub(super) const DEFAULT_LINT_COMPLETIONS: &[LintCompletion] = &[ | ||
39 | LintCompletion { label: "absolute_paths_not_starting_with_crate", description: r#"fully qualified paths that start with a module name instead of `crate`, `self`, or an extern crate name"# }, | ||
40 | LintCompletion { label: "anonymous_parameters", description: r#"detects anonymous parameters"# }, | ||
41 | LintCompletion { label: "box_pointers", description: r#"use of owned (Box type) heap memory"# }, | ||
42 | LintCompletion { label: "deprecated_in_future", description: r#"detects use of items that will be deprecated in a future version"# }, | ||
43 | LintCompletion { label: "elided_lifetimes_in_paths", description: r#"hidden lifetime parameters in types are deprecated"# }, | ||
44 | LintCompletion { label: "explicit_outlives_requirements", description: r#"outlives requirements can be inferred"# }, | ||
45 | LintCompletion { label: "indirect_structural_match", description: r#"pattern with const indirectly referencing non-structural-match type"# }, | ||
46 | LintCompletion { label: "keyword_idents", description: r#"detects edition keywords being used as an identifier"# }, | ||
47 | LintCompletion { label: "macro_use_extern_crate", description: r#"the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system"# }, | ||
48 | LintCompletion { label: "meta_variable_misuse", description: r#"possible meta-variable misuse at macro definition"# }, | ||
49 | LintCompletion { label: "missing_copy_implementations", description: r#"detects potentially-forgotten implementations of `Copy`"# }, | ||
50 | LintCompletion { label: "missing_crate_level_docs", description: r#"detects crates with no crate-level documentation"# }, | ||
51 | LintCompletion { label: "missing_debug_implementations", description: r#"detects missing implementations of Debug"# }, | ||
52 | LintCompletion { label: "missing_docs", description: r#"detects missing documentation for public members"# }, | ||
53 | LintCompletion { label: "missing_doc_code_examples", description: r#"detects publicly-exported items without code samples in their documentation"# }, | ||
54 | LintCompletion { label: "non_ascii_idents", description: r#"detects non-ASCII identifiers"# }, | ||
55 | LintCompletion { label: "private_doc_tests", description: r#"detects code samples in docs of private items not documented by rustdoc"# }, | ||
56 | LintCompletion { label: "single_use_lifetimes", description: r#"detects lifetime parameters that are only used once"# }, | ||
57 | LintCompletion { label: "trivial_casts", description: r#"detects trivial casts which could be removed"# }, | ||
58 | LintCompletion { label: "trivial_numeric_casts", description: r#"detects trivial casts of numeric types which could be removed"# }, | ||
59 | LintCompletion { label: "unaligned_references", description: r#"detects unaligned references to fields of packed structs"# }, | ||
60 | LintCompletion { label: "unreachable_pub", description: r#"`pub` items not reachable from crate root"# }, | ||
61 | LintCompletion { label: "unsafe_code", description: r#"usage of `unsafe` code"# }, | ||
62 | LintCompletion { label: "unsafe_op_in_unsafe_fn", description: r#"unsafe operations in unsafe functions without an explicit unsafe block are deprecated"# }, | ||
63 | LintCompletion { label: "unstable_features", description: r#"enabling unstable features (deprecated. do not use)"# }, | ||
64 | LintCompletion { label: "unused_crate_dependencies", description: r#"crate dependencies that are never used"# }, | ||
65 | LintCompletion { label: "unused_extern_crates", description: r#"extern crates that are never used"# }, | ||
66 | LintCompletion { label: "unused_import_braces", description: r#"unnecessary braces around an imported item"# }, | ||
67 | LintCompletion { label: "unused_lifetimes", description: r#"detects lifetime parameters that are never used"# }, | ||
68 | LintCompletion { label: "unused_qualifications", description: r#"detects unnecessarily qualified names"# }, | ||
69 | LintCompletion { label: "unused_results", description: r#"unused result of an expression in a statement"# }, | ||
70 | LintCompletion { label: "variant_size_differences", description: r#"detects enums with widely varying variant sizes"# }, | ||
71 | LintCompletion { label: "array_into_iter", description: r#"detects calling `into_iter` on arrays"# }, | ||
72 | LintCompletion { label: "asm_sub_register", description: r#"using only a subset of a register for inline asm inputs"# }, | ||
73 | LintCompletion { label: "bare_trait_objects", description: r#"suggest using `dyn Trait` for trait objects"# }, | ||
74 | LintCompletion { label: "bindings_with_variant_name", description: r#"detects pattern bindings with the same name as one of the matched variants"# }, | ||
75 | LintCompletion { label: "cenum_impl_drop_cast", description: r#"a C-like enum implementing Drop is cast"# }, | ||
76 | LintCompletion { label: "clashing_extern_declarations", description: r#"detects when an extern fn has been declared with the same name but different types"# }, | ||
77 | LintCompletion { label: "coherence_leak_check", description: r#"distinct impls distinguished only by the leak-check code"# }, | ||
78 | LintCompletion { label: "confusable_idents", description: r#"detects visually confusable pairs between identifiers"# }, | ||
79 | LintCompletion { label: "dead_code", description: r#"detect unused, unexported items"# }, | ||
80 | LintCompletion { label: "deprecated", description: r#"detects use of deprecated items"# }, | ||
81 | LintCompletion { label: "ellipsis_inclusive_range_patterns", description: r#"`...` range patterns are deprecated"# }, | ||
82 | LintCompletion { label: "exported_private_dependencies", description: r#"public interface leaks type from a private dependency"# }, | ||
83 | LintCompletion { label: "illegal_floating_point_literal_pattern", description: r#"floating-point literals cannot be used in patterns"# }, | ||
84 | LintCompletion { label: "improper_ctypes", description: r#"proper use of libc types in foreign modules"# }, | ||
85 | LintCompletion { label: "improper_ctypes_definitions", description: r#"proper use of libc types in foreign item definitions"# }, | ||
86 | LintCompletion { label: "incomplete_features", description: r#"incomplete features that may function improperly in some or all cases"# }, | ||
87 | LintCompletion { label: "inline_no_sanitize", description: r#"detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]`"# }, | ||
88 | LintCompletion { label: "intra_doc_link_resolution_failure", description: r#"failures in resolving intra-doc link targets"# }, | ||
89 | LintCompletion { label: "invalid_codeblock_attributes", description: r#"codeblock attribute looks a lot like a known one"# }, | ||
90 | LintCompletion { label: "invalid_value", description: r#"an invalid value is being created (such as a NULL reference)"# }, | ||
91 | LintCompletion { label: "irrefutable_let_patterns", description: r#"detects irrefutable patterns in if-let and while-let statements"# }, | ||
92 | LintCompletion { label: "late_bound_lifetime_arguments", description: r#"detects generic lifetime arguments in path segments with late bound lifetime parameters"# }, | ||
93 | LintCompletion { label: "mixed_script_confusables", description: r#"detects Unicode scripts whose mixed script confusables codepoints are solely used"# }, | ||
94 | LintCompletion { label: "mutable_borrow_reservation_conflict", description: r#"reservation of a two-phased borrow conflicts with other shared borrows"# }, | ||
95 | LintCompletion { label: "non_camel_case_types", description: r#"types, variants, traits and type parameters should have camel case names"# }, | ||
96 | LintCompletion { label: "non_shorthand_field_patterns", description: r#"using `Struct { x: x }` instead of `Struct { x }` in a pattern"# }, | ||
97 | LintCompletion { label: "non_snake_case", description: r#"variables, methods, functions, lifetime parameters and modules should have snake case names"# }, | ||
98 | LintCompletion { label: "non_upper_case_globals", description: r#"static constants should have uppercase identifiers"# }, | ||
99 | LintCompletion { label: "no_mangle_generic_items", description: r#"generic items must be mangled"# }, | ||
100 | LintCompletion { label: "overlapping_patterns", description: r#"detects overlapping patterns"# }, | ||
101 | LintCompletion { label: "path_statements", description: r#"path statements with no effect"# }, | ||
102 | LintCompletion { label: "private_in_public", description: r#"detect private items in public interfaces not caught by the old implementation"# }, | ||
103 | LintCompletion { label: "proc_macro_derive_resolution_fallback", description: r#"detects proc macro derives using inaccessible names from parent modules"# }, | ||
104 | LintCompletion { label: "redundant_semicolons", description: r#"detects unnecessary trailing semicolons"# }, | ||
105 | LintCompletion { label: "renamed_and_removed_lints", description: r#"lints that have been renamed or removed"# }, | ||
106 | LintCompletion { label: "safe_packed_borrows", description: r#"safe borrows of fields of packed structs were erroneously allowed"# }, | ||
107 | LintCompletion { label: "stable_features", description: r#"stable features found in `#[feature]` directive"# }, | ||
108 | LintCompletion { label: "trivial_bounds", description: r#"these bounds don't depend on an type parameters"# }, | ||
109 | LintCompletion { label: "type_alias_bounds", description: r#"bounds in type aliases are not enforced"# }, | ||
110 | LintCompletion { label: "tyvar_behind_raw_pointer", description: r#"raw pointer to an inference variable"# }, | ||
111 | LintCompletion { label: "uncommon_codepoints", description: r#"detects uncommon Unicode codepoints in identifiers"# }, | ||
112 | LintCompletion { label: "unconditional_recursion", description: r#"functions that cannot return without calling themselves"# }, | ||
113 | LintCompletion { label: "unknown_lints", description: r#"unrecognized lint attribute"# }, | ||
114 | LintCompletion { label: "unnameable_test_items", description: r#"detects an item that cannot be named being marked as `#[test_case]`"# }, | ||
115 | LintCompletion { label: "unreachable_code", description: r#"detects unreachable code paths"# }, | ||
116 | LintCompletion { label: "unreachable_patterns", description: r#"detects unreachable patterns"# }, | ||
117 | LintCompletion { label: "unstable_name_collisions", description: r#"detects name collision with an existing but unstable method"# }, | ||
118 | LintCompletion { label: "unused_allocation", description: r#"detects unnecessary allocations that can be eliminated"# }, | ||
119 | LintCompletion { label: "unused_assignments", description: r#"detect assignments that will never be read"# }, | ||
120 | LintCompletion { label: "unused_attributes", description: r#"detects attributes that were not used by the compiler"# }, | ||
121 | LintCompletion { label: "unused_braces", description: r#"unnecessary braces around an expression"# }, | ||
122 | LintCompletion { label: "unused_comparisons", description: r#"comparisons made useless by limits of the types involved"# }, | ||
123 | LintCompletion { label: "unused_doc_comments", description: r#"detects doc comments that aren't used by rustdoc"# }, | ||
124 | LintCompletion { label: "unused_features", description: r#"unused features found in crate-level `#[feature]` directives"# }, | ||
125 | LintCompletion { label: "unused_imports", description: r#"imports that are never used"# }, | ||
126 | LintCompletion { label: "unused_labels", description: r#"detects labels that are never used"# }, | ||
127 | LintCompletion { label: "unused_macros", description: r#"detects macros that were not used"# }, | ||
128 | LintCompletion { label: "unused_must_use", description: r#"unused result of a type flagged as `#[must_use]`"# }, | ||
129 | LintCompletion { label: "unused_mut", description: r#"detect mut variables which don't need to be mutable"# }, | ||
130 | LintCompletion { label: "unused_parens", description: r#"`if`, `match`, `while` and `return` do not need parentheses"# }, | ||
131 | LintCompletion { label: "unused_unsafe", description: r#"unnecessary use of an `unsafe` block"# }, | ||
132 | LintCompletion { label: "unused_variables", description: r#"detect variables which are not used in any way"# }, | ||
133 | LintCompletion { label: "warnings", description: r#"mass-change the level for lints which produce warnings"# }, | ||
134 | LintCompletion { label: "where_clauses_object_safety", description: r#"checks the object safety of where clauses"# }, | ||
135 | LintCompletion { label: "while_true", description: r#"suggest using `loop { }` instead of `while true { }`"# }, | ||
136 | LintCompletion { label: "ambiguous_associated_items", description: r#"ambiguous associated items"# }, | ||
137 | LintCompletion { label: "arithmetic_overflow", description: r#"arithmetic operation overflows"# }, | ||
138 | LintCompletion { label: "conflicting_repr_hints", description: r#"conflicts between `#[repr(..)]` hints that were previously accepted and used in practice"# }, | ||
139 | LintCompletion { label: "const_err", description: r#"constant evaluation detected erroneous expression"# }, | ||
140 | LintCompletion { label: "ill_formed_attribute_input", description: r#"ill-formed attribute inputs that were previously accepted and used in practice"# }, | ||
141 | LintCompletion { label: "incomplete_include", description: r#"trailing content in included file"# }, | ||
142 | LintCompletion { label: "invalid_type_param_default", description: r#"type parameter default erroneously allowed in invalid location"# }, | ||
143 | LintCompletion { label: "macro_expanded_macro_exports_accessed_by_absolute_paths", description: r#"macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths"# }, | ||
144 | LintCompletion { label: "missing_fragment_specifier", description: r#"detects missing fragment specifiers in unused `macro_rules!` patterns"# }, | ||
145 | LintCompletion { label: "mutable_transmutes", description: r#"mutating transmuted &mut T from &T may cause undefined behavior"# }, | ||
146 | LintCompletion { label: "no_mangle_const_items", description: r#"const items will not have their symbols exported"# }, | ||
147 | LintCompletion { label: "order_dependent_trait_objects", description: r#"trait-object types were treated as different depending on marker-trait order"# }, | ||
148 | LintCompletion { label: "overflowing_literals", description: r#"literal out of range for its type"# }, | ||
149 | LintCompletion { label: "patterns_in_fns_without_body", description: r#"patterns in functions without body were erroneously allowed"# }, | ||
150 | LintCompletion { label: "pub_use_of_private_extern_crate", description: r#"detect public re-exports of private extern crates"# }, | ||
151 | LintCompletion { label: "soft_unstable", description: r#"a feature gate that doesn't break dependent crates"# }, | ||
152 | LintCompletion { label: "unconditional_panic", description: r#"operation will cause a panic at runtime"# }, | ||
153 | LintCompletion { label: "unknown_crate_types", description: r#"unknown crate type found in `#[crate_type]` directive"# }, | ||
154 | ]; | ||
155 | |||
156 | #[cfg(test)] | 33 | #[cfg(test)] |
157 | mod tests { | 34 | mod tests { |
158 | 35 | ||
diff --git a/crates/ide_completion/src/lib.rs b/crates/ide_completion/src/lib.rs index 1152a9850..6fb38f50d 100644 --- a/crates/ide_completion/src/lib.rs +++ b/crates/ide_completion/src/lib.rs | |||
@@ -4,7 +4,6 @@ mod config; | |||
4 | mod item; | 4 | mod item; |
5 | mod context; | 5 | mod context; |
6 | mod patterns; | 6 | mod patterns; |
7 | mod generated_lint_completions; | ||
8 | #[cfg(test)] | 7 | #[cfg(test)] |
9 | mod test_utils; | 8 | mod test_utils; |
10 | mod render; | 9 | mod render; |
diff --git a/crates/ide_db/src/helpers.rs b/crates/ide_db/src/helpers.rs index 21b48237a..00900cdc2 100644 --- a/crates/ide_db/src/helpers.rs +++ b/crates/ide_db/src/helpers.rs | |||
@@ -3,6 +3,7 @@ pub mod import_assets; | |||
3 | pub mod insert_use; | 3 | pub mod insert_use; |
4 | pub mod merge_imports; | 4 | pub mod merge_imports; |
5 | pub mod rust_doc; | 5 | pub mod rust_doc; |
6 | pub mod generated_lints; | ||
6 | 7 | ||
7 | use std::collections::VecDeque; | 8 | use std::collections::VecDeque; |
8 | 9 | ||
diff --git a/crates/ide_completion/src/generated_lint_completions.rs b/crates/ide_db/src/helpers/generated_lints.rs index 0d405350d..6ccb0478e 100644 --- a/crates/ide_completion/src/generated_lint_completions.rs +++ b/crates/ide_db/src/helpers/generated_lints.rs | |||
@@ -1,320 +1,487 @@ | |||
1 | //! Generated file, do not edit by hand, see `xtask/src/codegen` | 1 | //! Generated file, do not edit by hand, see `xtask/src/codegen` |
2 | 2 | ||
3 | use crate::completions::attribute::LintCompletion; | 3 | pub struct Lint { |
4 | pub(super) const FEATURES: &[LintCompletion] = &[ | 4 | pub label: &'static str, |
5 | LintCompletion { | 5 | pub description: &'static str, |
6 | label: "plugin_registrar", | ||
7 | description: r##"# `plugin_registrar` | ||
8 | |||
9 | The tracking issue for this feature is: [#29597] | ||
10 | |||
11 | [#29597]: https://github.com/rust-lang/rust/issues/29597 | ||
12 | |||
13 | This feature is part of "compiler plugins." It will often be used with the | ||
14 | [`plugin`] and `rustc_private` features as well. For more details, see | ||
15 | their docs. | ||
16 | |||
17 | [`plugin`]: plugin.md | ||
18 | |||
19 | ------------------------ | ||
20 | "##, | ||
21 | }, | ||
22 | LintCompletion { | ||
23 | label: "inline_const", | ||
24 | description: r##"# `inline_const` | ||
25 | |||
26 | The tracking issue for this feature is: [#76001] | ||
27 | |||
28 | ------ | ||
29 | |||
30 | This feature allows you to use inline constant expressions. For example, you can | ||
31 | turn this code: | ||
32 | |||
33 | ```rust | ||
34 | # fn add_one(x: i32) -> i32 { x + 1 } | ||
35 | const MY_COMPUTATION: i32 = 1 + 2 * 3 / 4; | ||
36 | |||
37 | fn main() { | ||
38 | let x = add_one(MY_COMPUTATION); | ||
39 | } | 6 | } |
40 | ``` | ||
41 | |||
42 | into this code: | ||
43 | |||
44 | ```rust | ||
45 | #![feature(inline_const)] | ||
46 | 7 | ||
47 | # fn add_one(x: i32) -> i32 { x + 1 } | 8 | pub const DEFAULT_LINTS: &[Lint] = &[ |
48 | fn main() { | 9 | Lint { |
49 | let x = add_one(const { 1 + 2 * 3 / 4 }); | 10 | label: "absolute_paths_not_starting_with_crate", |
50 | } | 11 | description: r##"fully qualified paths that start with a module name instead of `crate`, `self`, or an extern crate name"##, |
51 | ``` | 12 | }, |
52 | 13 | Lint { label: "ambiguous_associated_items", description: r##"ambiguous associated items"## }, | |
53 | You can also use inline constant expressions in patterns: | 14 | Lint { label: "anonymous_parameters", description: r##"detects anonymous parameters"## }, |
54 | 15 | Lint { label: "arithmetic_overflow", description: r##"arithmetic operation overflows"## }, | |
55 | ```rust | 16 | Lint { label: "array_into_iter", description: r##"detects calling `into_iter` on arrays"## }, |
56 | #![feature(inline_const)] | 17 | Lint { |
57 | 18 | label: "asm_sub_register", | |
58 | const fn one() -> i32 { 1 } | 19 | description: r##"using only a subset of a register for inline asm inputs"##, |
59 | 20 | }, | |
60 | let some_int = 3; | 21 | Lint { label: "bad_asm_style", description: r##"incorrect use of inline assembly"## }, |
61 | match some_int { | 22 | Lint { |
62 | const { 1 + 2 } => println!("Matched 1 + 2"), | 23 | label: "bare_trait_objects", |
63 | const { one() } => println!("Matched const fn returning 1"), | 24 | description: r##"suggest using `dyn Trait` for trait objects"##, |
64 | _ => println!("Didn't match anything :("), | 25 | }, |
65 | } | 26 | Lint { |
66 | ``` | 27 | label: "bindings_with_variant_name", |
67 | 28 | description: r##"detects pattern bindings with the same name as one of the matched variants"##, | |
68 | [#76001]: https://github.com/rust-lang/rust/issues/76001 | 29 | }, |
69 | "##, | 30 | Lint { label: "box_pointers", description: r##"use of owned (Box type) heap memory"## }, |
31 | Lint { | ||
32 | label: "cenum_impl_drop_cast", | ||
33 | description: r##"a C-like enum implementing Drop is cast"##, | ||
34 | }, | ||
35 | Lint { | ||
36 | label: "clashing_extern_declarations", | ||
37 | description: r##"detects when an extern fn has been declared with the same name but different types"##, | ||
38 | }, | ||
39 | Lint { | ||
40 | label: "coherence_leak_check", | ||
41 | description: r##"distinct impls distinguished only by the leak-check code"##, | ||
42 | }, | ||
43 | Lint { | ||
44 | label: "conflicting_repr_hints", | ||
45 | description: r##"conflicts between `#[repr(..)]` hints that were previously accepted and used in practice"##, | ||
46 | }, | ||
47 | Lint { | ||
48 | label: "confusable_idents", | ||
49 | description: r##"detects visually confusable pairs between identifiers"##, | ||
50 | }, | ||
51 | Lint { | ||
52 | label: "const_err", | ||
53 | description: r##"constant evaluation encountered erroneous expression"##, | ||
54 | }, | ||
55 | Lint { | ||
56 | label: "const_evaluatable_unchecked", | ||
57 | description: r##"detects a generic constant is used in a type without a emitting a warning"##, | ||
58 | }, | ||
59 | Lint { | ||
60 | label: "const_item_mutation", | ||
61 | description: r##"detects attempts to mutate a `const` item"##, | ||
62 | }, | ||
63 | Lint { label: "dead_code", description: r##"detect unused, unexported items"## }, | ||
64 | Lint { label: "deprecated", description: r##"detects use of deprecated items"## }, | ||
65 | Lint { | ||
66 | label: "deprecated_in_future", | ||
67 | description: r##"detects use of items that will be deprecated in a future version"##, | ||
68 | }, | ||
69 | Lint { | ||
70 | label: "deref_nullptr", | ||
71 | description: r##"detects when an null pointer is dereferenced"##, | ||
72 | }, | ||
73 | Lint { | ||
74 | label: "disjoint_capture_migration", | ||
75 | description: r##"Drop reorder and auto traits error because of `capture_disjoint_fields`"##, | ||
76 | }, | ||
77 | Lint { label: "drop_bounds", description: r##"bounds of the form `T: Drop` are useless"## }, | ||
78 | Lint { | ||
79 | label: "elided_lifetimes_in_paths", | ||
80 | description: r##"hidden lifetime parameters in types are deprecated"##, | ||
81 | }, | ||
82 | Lint { | ||
83 | label: "ellipsis_inclusive_range_patterns", | ||
84 | description: r##"`...` range patterns are deprecated"##, | ||
85 | }, | ||
86 | Lint { | ||
87 | label: "explicit_outlives_requirements", | ||
88 | description: r##"outlives requirements can be inferred"##, | ||
89 | }, | ||
90 | Lint { | ||
91 | label: "exported_private_dependencies", | ||
92 | description: r##"public interface leaks type from a private dependency"##, | ||
93 | }, | ||
94 | Lint { label: "forbidden_lint_groups", description: r##"applying forbid to lint-groups"## }, | ||
95 | Lint { | ||
96 | label: "function_item_references", | ||
97 | description: r##"suggest casting to a function pointer when attempting to take references to function items"##, | ||
98 | }, | ||
99 | Lint { | ||
100 | label: "future_incompatible", | ||
101 | description: r##"lint group for: keyword-idents, anonymous-parameters, ellipsis-inclusive-range-patterns, 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, tyvar-behind-raw-pointer, bare-trait-objects, absolute-paths-not-starting-with-crate, 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, semicolon-in-expressions-from-macros, legacy-derive-helpers, proc-macro-back-compat, array-into-iter"##, | ||
102 | }, | ||
103 | Lint { | ||
104 | label: "ill_formed_attribute_input", | ||
105 | description: r##"ill-formed attribute inputs that were previously accepted and used in practice"##, | ||
106 | }, | ||
107 | Lint { | ||
108 | label: "illegal_floating_point_literal_pattern", | ||
109 | description: r##"floating-point literals cannot be used in patterns"##, | ||
110 | }, | ||
111 | Lint { | ||
112 | label: "improper_ctypes", | ||
113 | description: r##"proper use of libc types in foreign modules"##, | ||
114 | }, | ||
115 | Lint { | ||
116 | label: "improper_ctypes_definitions", | ||
117 | description: r##"proper use of libc types in foreign item definitions"##, | ||
118 | }, | ||
119 | Lint { | ||
120 | label: "incomplete_features", | ||
121 | description: r##"incomplete features that may function improperly in some or all cases"##, | ||
122 | }, | ||
123 | Lint { label: "incomplete_include", description: r##"trailing content in included file"## }, | ||
124 | Lint { | ||
125 | label: "indirect_structural_match", | ||
126 | description: r##"constant used in pattern contains value of non-structural-match type in a field or a variant"##, | ||
127 | }, | ||
128 | Lint { | ||
129 | label: "ineffective_unstable_trait_impl", | ||
130 | description: r##"detects `#[unstable]` on stable trait implementations for stable types"##, | ||
131 | }, | ||
132 | Lint { | ||
133 | label: "inline_no_sanitize", | ||
134 | description: r##"detects incompatible use of `#[inline(always)]` and `#[no_sanitize(...)]`"##, | ||
135 | }, | ||
136 | Lint { | ||
137 | label: "invalid_type_param_default", | ||
138 | description: r##"type parameter default erroneously allowed in invalid location"##, | ||
139 | }, | ||
140 | Lint { | ||
141 | label: "invalid_value", | ||
142 | description: r##"an invalid value is being created (such as a null reference)"##, | ||
143 | }, | ||
144 | Lint { | ||
145 | label: "irrefutable_let_patterns", | ||
146 | description: r##"detects irrefutable patterns in `if let` and `while let` statements"##, | ||
147 | }, | ||
148 | Lint { | ||
149 | label: "keyword_idents", | ||
150 | description: r##"detects edition keywords being used as an identifier"##, | ||
151 | }, | ||
152 | Lint { label: "large_assignments", description: r##"detects large moves or copies"## }, | ||
153 | Lint { | ||
154 | label: "late_bound_lifetime_arguments", | ||
155 | description: r##"detects generic lifetime arguments in path segments with late bound lifetime parameters"##, | ||
156 | }, | ||
157 | Lint { | ||
158 | label: "legacy_derive_helpers", | ||
159 | description: r##"detects derive helper attributes that are used before they are introduced"##, | ||
160 | }, | ||
161 | Lint { | ||
162 | label: "macro_expanded_macro_exports_accessed_by_absolute_paths", | ||
163 | description: r##"macro-expanded `macro_export` macros from the current crate cannot be referred to by absolute paths"##, | ||
164 | }, | ||
165 | Lint { | ||
166 | label: "macro_use_extern_crate", | ||
167 | description: r##"the `#[macro_use]` attribute is now deprecated in favor of using macros via the module system"##, | ||
168 | }, | ||
169 | Lint { | ||
170 | label: "meta_variable_misuse", | ||
171 | description: r##"possible meta-variable misuse at macro definition"##, | ||
172 | }, | ||
173 | Lint { label: "missing_abi", description: r##"No declared ABI for extern declaration"## }, | ||
174 | Lint { | ||
175 | label: "missing_copy_implementations", | ||
176 | description: r##"detects potentially-forgotten implementations of `Copy`"##, | ||
177 | }, | ||
178 | Lint { | ||
179 | label: "missing_debug_implementations", | ||
180 | description: r##"detects missing implementations of Debug"##, | ||
181 | }, | ||
182 | Lint { | ||
183 | label: "missing_docs", | ||
184 | description: r##"detects missing documentation for public members"##, | ||
185 | }, | ||
186 | Lint { | ||
187 | label: "missing_fragment_specifier", | ||
188 | description: r##"detects missing fragment specifiers in unused `macro_rules!` patterns"##, | ||
189 | }, | ||
190 | Lint { | ||
191 | label: "mixed_script_confusables", | ||
192 | description: r##"detects Unicode scripts whose mixed script confusables codepoints are solely used"##, | ||
193 | }, | ||
194 | Lint { | ||
195 | label: "mutable_borrow_reservation_conflict", | ||
196 | description: r##"reservation of a two-phased borrow conflicts with other shared borrows"##, | ||
197 | }, | ||
198 | Lint { | ||
199 | label: "mutable_transmutes", | ||
200 | description: r##"mutating transmuted &mut T from &T may cause undefined behavior"##, | ||
201 | }, | ||
202 | Lint { | ||
203 | label: "no_mangle_const_items", | ||
204 | description: r##"const items will not have their symbols exported"##, | ||
205 | }, | ||
206 | Lint { label: "no_mangle_generic_items", description: r##"generic items must be mangled"## }, | ||
207 | Lint { label: "non_ascii_idents", description: r##"detects non-ASCII identifiers"## }, | ||
208 | Lint { | ||
209 | label: "non_camel_case_types", | ||
210 | description: r##"types, variants, traits and type parameters should have camel case names"##, | ||
211 | }, | ||
212 | Lint { | ||
213 | label: "non_fmt_panic", | ||
214 | description: r##"detect single-argument panic!() invocations in which the argument is not a format string"##, | ||
215 | }, | ||
216 | Lint { | ||
217 | label: "non_shorthand_field_patterns", | ||
218 | description: r##"using `Struct { x: x }` instead of `Struct { x }` in a pattern"##, | ||
219 | }, | ||
220 | Lint { | ||
221 | label: "non_snake_case", | ||
222 | description: r##"variables, methods, functions, lifetime parameters and modules should have snake case names"##, | ||
223 | }, | ||
224 | Lint { | ||
225 | label: "non_upper_case_globals", | ||
226 | description: r##"static constants should have uppercase identifiers"##, | ||
227 | }, | ||
228 | Lint { | ||
229 | label: "nonstandard_style", | ||
230 | description: r##"lint group for: non-camel-case-types, non-snake-case, non-upper-case-globals"##, | ||
231 | }, | ||
232 | Lint { | ||
233 | label: "nontrivial_structural_match", | ||
234 | description: r##"constant used in pattern of non-structural-match type and the constant's initializer expression contains values of non-structural-match types"##, | ||
235 | }, | ||
236 | Lint { | ||
237 | label: "noop_method_call", | ||
238 | description: r##"detects the use of well-known noop methods"##, | ||
239 | }, | ||
240 | Lint { | ||
241 | label: "or_patterns_back_compat", | ||
242 | description: r##"detects usage of old versions of or-patterns"##, | ||
243 | }, | ||
244 | Lint { | ||
245 | label: "order_dependent_trait_objects", | ||
246 | description: r##"trait-object types were treated as different depending on marker-trait order"##, | ||
247 | }, | ||
248 | Lint { label: "overflowing_literals", description: r##"literal out of range for its type"## }, | ||
249 | Lint { | ||
250 | label: "overlapping_range_endpoints", | ||
251 | description: r##"detects range patterns with overlapping endpoints"##, | ||
252 | }, | ||
253 | Lint { label: "path_statements", description: r##"path statements with no effect"## }, | ||
254 | Lint { | ||
255 | label: "patterns_in_fns_without_body", | ||
256 | description: r##"patterns in functions without body were erroneously allowed"##, | ||
257 | }, | ||
258 | Lint { | ||
259 | label: "pointer_structural_match", | ||
260 | description: r##"pointers are not structural-match"##, | ||
261 | }, | ||
262 | Lint { | ||
263 | label: "private_in_public", | ||
264 | description: r##"detect private items in public interfaces not caught by the old implementation"##, | ||
265 | }, | ||
266 | Lint { | ||
267 | label: "proc_macro_back_compat", | ||
268 | description: r##"detects usage of old versions of certain proc-macro crates"##, | ||
269 | }, | ||
270 | Lint { | ||
271 | label: "proc_macro_derive_resolution_fallback", | ||
272 | description: r##"detects proc macro derives using inaccessible names from parent modules"##, | ||
273 | }, | ||
274 | Lint { | ||
275 | label: "pub_use_of_private_extern_crate", | ||
276 | description: r##"detect public re-exports of private extern crates"##, | ||
277 | }, | ||
278 | Lint { | ||
279 | label: "redundant_semicolons", | ||
280 | description: r##"detects unnecessary trailing semicolons"##, | ||
281 | }, | ||
282 | Lint { | ||
283 | label: "renamed_and_removed_lints", | ||
284 | description: r##"lints that have been renamed or removed"##, | ||
285 | }, | ||
286 | Lint { | ||
287 | label: "rust_2018_compatibility", | ||
288 | description: r##"lint group for: keyword-idents, anonymous-parameters, tyvar-behind-raw-pointer, absolute-paths-not-starting-with-crate"##, | ||
289 | }, | ||
290 | Lint { | ||
291 | label: "rust_2018_idioms", | ||
292 | description: r##"lint group for: bare-trait-objects, unused-extern-crates, ellipsis-inclusive-range-patterns, elided-lifetimes-in-paths, explicit-outlives-requirements"##, | ||
293 | }, | ||
294 | Lint { | ||
295 | label: "rust_2021_compatibility", | ||
296 | description: r##"lint group for: ellipsis-inclusive-range-patterns, bare-trait-objects"##, | ||
297 | }, | ||
298 | Lint { | ||
299 | label: "semicolon_in_expressions_from_macros", | ||
300 | description: r##"trailing semicolon in macro body used as expression"##, | ||
301 | }, | ||
302 | Lint { | ||
303 | label: "single_use_lifetimes", | ||
304 | description: r##"detects lifetime parameters that are only used once"##, | ||
305 | }, | ||
306 | Lint { | ||
307 | label: "soft_unstable", | ||
308 | description: r##"a feature gate that doesn't break dependent crates"##, | ||
309 | }, | ||
310 | Lint { | ||
311 | label: "stable_features", | ||
312 | description: r##"stable features found in `#[feature]` directive"##, | ||
313 | }, | ||
314 | Lint { | ||
315 | label: "temporary_cstring_as_ptr", | ||
316 | description: r##"detects getting the inner pointer of a temporary `CString`"##, | ||
317 | }, | ||
318 | Lint { | ||
319 | label: "trivial_bounds", | ||
320 | description: r##"these bounds don't depend on an type parameters"##, | ||
321 | }, | ||
322 | Lint { | ||
323 | label: "trivial_casts", | ||
324 | description: r##"detects trivial casts which could be removed"##, | ||
325 | }, | ||
326 | Lint { | ||
327 | label: "trivial_numeric_casts", | ||
328 | description: r##"detects trivial casts of numeric types which could be removed"##, | ||
329 | }, | ||
330 | Lint { | ||
331 | label: "type_alias_bounds", | ||
332 | description: r##"bounds in type aliases are not enforced"##, | ||
333 | }, | ||
334 | Lint { | ||
335 | label: "tyvar_behind_raw_pointer", | ||
336 | description: r##"raw pointer to an inference variable"##, | ||
337 | }, | ||
338 | Lint { | ||
339 | label: "unaligned_references", | ||
340 | description: r##"detects unaligned references to fields of packed structs"##, | ||
341 | }, | ||
342 | Lint { | ||
343 | label: "uncommon_codepoints", | ||
344 | description: r##"detects uncommon Unicode codepoints in identifiers"##, | ||
345 | }, | ||
346 | Lint { | ||
347 | label: "unconditional_panic", | ||
348 | description: r##"operation will cause a panic at runtime"##, | ||
349 | }, | ||
350 | Lint { | ||
351 | label: "unconditional_recursion", | ||
352 | description: r##"functions that cannot return without calling themselves"##, | ||
353 | }, | ||
354 | Lint { label: "uninhabited_static", description: r##"uninhabited static"## }, | ||
355 | Lint { | ||
356 | label: "unknown_crate_types", | ||
357 | description: r##"unknown crate type found in `#[crate_type]` directive"##, | ||
358 | }, | ||
359 | Lint { label: "unknown_lints", description: r##"unrecognized lint attribute"## }, | ||
360 | Lint { | ||
361 | label: "unnameable_test_items", | ||
362 | description: r##"detects an item that cannot be named being marked as `#[test_case]`"##, | ||
363 | }, | ||
364 | Lint { label: "unreachable_code", description: r##"detects unreachable code paths"## }, | ||
365 | Lint { label: "unreachable_patterns", description: r##"detects unreachable patterns"## }, | ||
366 | Lint { | ||
367 | label: "unreachable_pub", | ||
368 | description: r##"`pub` items not reachable from crate root"##, | ||
369 | }, | ||
370 | Lint { label: "unsafe_code", description: r##"usage of `unsafe` code"## }, | ||
371 | Lint { | ||
372 | label: "unsafe_op_in_unsafe_fn", | ||
373 | description: r##"unsafe operations in unsafe functions without an explicit unsafe block are deprecated"##, | ||
374 | }, | ||
375 | Lint { | ||
376 | label: "unstable_features", | ||
377 | description: r##"enabling unstable features (deprecated. do not use)"##, | ||
378 | }, | ||
379 | Lint { | ||
380 | label: "unstable_name_collisions", | ||
381 | description: r##"detects name collision with an existing but unstable method"##, | ||
382 | }, | ||
383 | Lint { | ||
384 | label: "unsupported_naked_functions", | ||
385 | description: r##"unsupported naked function definitions"##, | ||
386 | }, | ||
387 | Lint { | ||
388 | label: "unused", | ||
389 | description: r##"lint group for: 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"##, | ||
390 | }, | ||
391 | Lint { | ||
392 | label: "unused_allocation", | ||
393 | description: r##"detects unnecessary allocations that can be eliminated"##, | ||
394 | }, | ||
395 | Lint { | ||
396 | label: "unused_assignments", | ||
397 | description: r##"detect assignments that will never be read"##, | ||
398 | }, | ||
399 | Lint { | ||
400 | label: "unused_attributes", | ||
401 | description: r##"detects attributes that were not used by the compiler"##, | ||
402 | }, | ||
403 | Lint { label: "unused_braces", description: r##"unnecessary braces around an expression"## }, | ||
404 | Lint { | ||
405 | label: "unused_comparisons", | ||
406 | description: r##"comparisons made useless by limits of the types involved"##, | ||
407 | }, | ||
408 | Lint { | ||
409 | label: "unused_crate_dependencies", | ||
410 | description: r##"crate dependencies that are never used"##, | ||
411 | }, | ||
412 | Lint { | ||
413 | label: "unused_doc_comments", | ||
414 | description: r##"detects doc comments that aren't used by rustdoc"##, | ||
415 | }, | ||
416 | Lint { label: "unused_extern_crates", description: r##"extern crates that are never used"## }, | ||
417 | Lint { | ||
418 | label: "unused_features", | ||
419 | description: r##"unused features found in crate-level `#[feature]` directives"##, | ||
420 | }, | ||
421 | Lint { | ||
422 | label: "unused_import_braces", | ||
423 | description: r##"unnecessary braces around an imported item"##, | ||
424 | }, | ||
425 | Lint { label: "unused_imports", description: r##"imports that are never used"## }, | ||
426 | Lint { label: "unused_labels", description: r##"detects labels that are never used"## }, | ||
427 | Lint { | ||
428 | label: "unused_lifetimes", | ||
429 | description: r##"detects lifetime parameters that are never used"##, | ||
430 | }, | ||
431 | Lint { label: "unused_macros", description: r##"detects macros that were not used"## }, | ||
432 | Lint { | ||
433 | label: "unused_must_use", | ||
434 | description: r##"unused result of a type flagged as `#[must_use]`"##, | ||
435 | }, | ||
436 | Lint { | ||
437 | label: "unused_mut", | ||
438 | description: r##"detect mut variables which don't need to be mutable"##, | ||
439 | }, | ||
440 | Lint { | ||
441 | label: "unused_parens", | ||
442 | description: r##"`if`, `match`, `while` and `return` do not need parentheses"##, | ||
443 | }, | ||
444 | Lint { | ||
445 | label: "unused_qualifications", | ||
446 | description: r##"detects unnecessarily qualified names"##, | ||
447 | }, | ||
448 | Lint { | ||
449 | label: "unused_results", | ||
450 | description: r##"unused result of an expression in a statement"##, | ||
451 | }, | ||
452 | Lint { label: "unused_unsafe", description: r##"unnecessary use of an `unsafe` block"## }, | ||
453 | Lint { | ||
454 | label: "unused_variables", | ||
455 | description: r##"detect variables which are not used in any way"##, | ||
456 | }, | ||
457 | Lint { | ||
458 | label: "useless_deprecated", | ||
459 | description: r##"detects deprecation attributes with no effect"##, | ||
460 | }, | ||
461 | Lint { | ||
462 | label: "variant_size_differences", | ||
463 | description: r##"detects enums with widely varying variant sizes"##, | ||
464 | }, | ||
465 | Lint { | ||
466 | label: "warnings", | ||
467 | description: r##"mass-change the level for lints which produce warnings"##, | ||
468 | }, | ||
469 | Lint { | ||
470 | label: "warnings", | ||
471 | description: r##"lint group for: all lints that are set to issue warnings"##, | ||
472 | }, | ||
473 | Lint { | ||
474 | label: "where_clauses_object_safety", | ||
475 | description: r##"checks the object safety of where clauses"##, | ||
476 | }, | ||
477 | Lint { | ||
478 | label: "while_true", | ||
479 | description: r##"suggest using `loop { }` instead of `while true { }`"##, | ||
70 | }, | 480 | }, |
71 | LintCompletion { | 481 | ]; |
72 | label: "auto_traits", | ||
73 | description: r##"# `auto_traits` | ||
74 | |||
75 | The tracking issue for this feature is [#13231] | ||
76 | |||
77 | [#13231]: https://github.com/rust-lang/rust/issues/13231 | ||
78 | |||
79 | ---- | ||
80 | |||
81 | The `auto_traits` feature gate allows you to define auto traits. | ||
82 | |||
83 | Auto traits, like [`Send`] or [`Sync`] in the standard library, are marker traits | ||
84 | that are automatically implemented for every type, unless the type, or a type it contains, | ||
85 | has explicitly opted out via a negative impl. (Negative impls are separately controlled | ||
86 | by the `negative_impls` feature.) | ||
87 | |||
88 | [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html | ||
89 | [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html | ||
90 | |||
91 | ```rust,ignore (partial-example) | ||
92 | impl !Trait for Type {} | ||
93 | ``` | ||
94 | |||
95 | Example: | ||
96 | |||
97 | ```rust | ||
98 | #![feature(negative_impls)] | ||
99 | #![feature(auto_traits)] | ||
100 | |||
101 | auto trait Valid {} | ||
102 | |||
103 | struct True; | ||
104 | struct False; | ||
105 | |||
106 | impl !Valid for False {} | ||
107 | |||
108 | struct MaybeValid<T>(T); | ||
109 | |||
110 | fn must_be_valid<T: Valid>(_t: T) { } | ||
111 | |||
112 | fn main() { | ||
113 | // works | ||
114 | must_be_valid( MaybeValid(True) ); | ||
115 | |||
116 | // compiler error - trait bound not satisfied | ||
117 | // must_be_valid( MaybeValid(False) ); | ||
118 | } | ||
119 | ``` | ||
120 | |||
121 | ## Automatic trait implementations | ||
122 | |||
123 | When a type is declared as an `auto trait`, we will automatically | ||
124 | create impls for every struct/enum/union, unless an explicit impl is | ||
125 | provided. These automatic impls contain a where clause for each field | ||
126 | of the form `T: AutoTrait`, where `T` is the type of the field and | ||
127 | `AutoTrait` is the auto trait in question. As an example, consider the | ||
128 | struct `List` and the auto trait `Send`: | ||
129 | |||
130 | ```rust | ||
131 | struct List<T> { | ||
132 | data: T, | ||
133 | next: Option<Box<List<T>>>, | ||
134 | } | ||
135 | ``` | ||
136 | |||
137 | Presuming that there is no explicit impl of `Send` for `List`, the | ||
138 | compiler will supply an automatic impl of the form: | ||
139 | |||
140 | ```rust | ||
141 | struct List<T> { | ||
142 | data: T, | ||
143 | next: Option<Box<List<T>>>, | ||
144 | } | ||
145 | |||
146 | unsafe impl<T> Send for List<T> | ||
147 | where | ||
148 | T: Send, // from the field `data` | ||
149 | Option<Box<List<T>>>: Send, // from the field `next` | ||
150 | { } | ||
151 | ``` | ||
152 | |||
153 | Explicit impls may be either positive or negative. They take the form: | ||
154 | |||
155 | ```rust,ignore (partial-example) | ||
156 | impl<...> AutoTrait for StructName<..> { } | ||
157 | impl<...> !AutoTrait for StructName<..> { } | ||
158 | ``` | ||
159 | |||
160 | ## Coinduction: Auto traits permit cyclic matching | ||
161 | |||
162 | Unlike ordinary trait matching, auto traits are **coinductive**. This | ||
163 | means, in short, that cycles which occur in trait matching are | ||
164 | considered ok. As an example, consider the recursive struct `List` | ||
165 | introduced in the previous section. In attempting to determine whether | ||
166 | `List: Send`, we would wind up in a cycle: to apply the impl, we must | ||
167 | show that `Option<Box<List>>: Send`, which will in turn require | ||
168 | `Box<List>: Send` and then finally `List: Send` again. Under ordinary | ||
169 | trait matching, this cycle would be an error, but for an auto trait it | ||
170 | is considered a successful match. | ||
171 | |||
172 | ## Items | ||
173 | |||
174 | Auto traits cannot have any trait items, such as methods or associated types. This ensures that we can generate default implementations. | ||
175 | |||
176 | ## Supertraits | ||
177 | |||
178 | Auto traits cannot have supertraits. This is for soundness reasons, as the interaction of coinduction with implied bounds is difficult to reconcile. | ||
179 | "##, | ||
180 | }, | ||
181 | LintCompletion { | ||
182 | label: "ffi_const", | ||
183 | description: r##"# `ffi_const` | ||
184 | |||
185 | The tracking issue for this feature is: [#58328] | ||
186 | |||
187 | ------ | ||
188 | |||
189 | The `#[ffi_const]` attribute applies clang's `const` attribute to foreign | ||
190 | functions declarations. | ||
191 | |||
192 | That is, `#[ffi_const]` functions shall have no effects except for its return | ||
193 | value, which can only depend on the values of the function parameters, and is | ||
194 | not affected by changes to the observable state of the program. | ||
195 | |||
196 | Applying the `#[ffi_const]` attribute to a function that violates these | ||
197 | requirements is undefined behaviour. | ||
198 | |||
199 | This attribute enables Rust to perform common optimizations, like sub-expression | ||
200 | elimination, and it can avoid emitting some calls in repeated invocations of the | ||
201 | function with the same argument values regardless of other operations being | ||
202 | performed in between these functions calls (as opposed to `#[ffi_pure]` | ||
203 | functions). | ||
204 | |||
205 | ## Pitfalls | ||
206 | |||
207 | A `#[ffi_const]` function can only read global memory that would not affect | ||
208 | its return value for the whole execution of the program (e.g. immutable global | ||
209 | memory). `#[ffi_const]` functions are referentially-transparent and therefore | ||
210 | more strict than `#[ffi_pure]` functions. | ||
211 | |||
212 | A common pitfall involves applying the `#[ffi_const]` attribute to a | ||
213 | function that reads memory through pointer arguments which do not necessarily | ||
214 | point to immutable global memory. | ||
215 | |||
216 | A `#[ffi_const]` function that returns unit has no effect on the abstract | ||
217 | machine's state, and a `#[ffi_const]` function cannot be `#[ffi_pure]`. | ||
218 | |||
219 | A `#[ffi_const]` function must not diverge, neither via a side effect (e.g. a | ||
220 | call to `abort`) nor by infinite loops. | ||
221 | |||
222 | When translating C headers to Rust FFI, it is worth verifying for which targets | ||
223 | the `const` attribute is enabled in those headers, and using the appropriate | ||
224 | `cfg` macros in the Rust side to match those definitions. While the semantics of | ||
225 | `const` are implemented identically by many C and C++ compilers, e.g., clang, | ||
226 | [GCC], [ARM C/C++ compiler], [IBM ILE C/C++], etc. they are not necessarily | ||
227 | implemented in this way on all of them. It is therefore also worth verifying | ||
228 | that the semantics of the C toolchain used to compile the binary being linked | ||
229 | against are compatible with those of the `#[ffi_const]`. | ||
230 | |||
231 | [#58328]: https://github.com/rust-lang/rust/issues/58328 | ||
232 | [ARM C/C++ compiler]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0491c/Cacgigch.html | ||
233 | [GCC]: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-const-function-attribute | ||
234 | [IBM ILE C/C++]: https://www.ibm.com/support/knowledgecenter/fr/ssw_ibm_i_71/rzarg/fn_attrib_const.htm | ||
235 | "##, | ||
236 | }, | ||
237 | LintCompletion { | ||
238 | label: "external_doc", | ||
239 | description: r##"# `external_doc` | ||
240 | |||
241 | The tracking issue for this feature is: [#44732] | ||
242 | |||
243 | The `external_doc` feature allows the use of the `include` parameter to the `#[doc]` attribute, to | ||
244 | include external files in documentation. Use the attribute in place of, or in addition to, regular | ||
245 | doc comments and `#[doc]` attributes, and `rustdoc` will load the given file when it renders | ||
246 | documentation for your crate. | ||
247 | |||
248 | With the following files in the same directory: | ||
249 | |||
250 | `external-doc.md`: | ||
251 | |||
252 | ```markdown | ||
253 | # My Awesome Type | ||
254 | |||
255 | This is the documentation for this spectacular type. | ||
256 | ``` | ||
257 | |||
258 | `lib.rs`: | ||
259 | |||
260 | ```no_run (needs-external-files) | ||
261 | #![feature(external_doc)] | ||
262 | |||
263 | #[doc(include = "external-doc.md")] | ||
264 | pub struct MyAwesomeType; | ||
265 | ``` | ||
266 | |||
267 | `rustdoc` will load the file `external-doc.md` and use it as the documentation for the `MyAwesomeType` | ||
268 | struct. | ||
269 | |||
270 | When locating files, `rustdoc` will base paths in the `src/` directory, as if they were alongside the | ||
271 | `lib.rs` for your crate. So if you want a `docs/` folder to live alongside the `src/` directory, | ||
272 | start your paths with `../docs/` for `rustdoc` to properly find the file. | ||
273 | |||
274 | This feature was proposed in [RFC #1990] and initially implemented in PR [#44781]. | ||
275 | |||
276 | [#44732]: https://github.com/rust-lang/rust/issues/44732 | ||
277 | [RFC #1990]: https://github.com/rust-lang/rfcs/pull/1990 | ||
278 | [#44781]: https://github.com/rust-lang/rust/pull/44781 | ||
279 | "##, | ||
280 | }, | ||
281 | LintCompletion { | ||
282 | label: "box_patterns", | ||
283 | description: r##"# `box_patterns` | ||
284 | |||
285 | The tracking issue for this feature is: [#29641] | ||
286 | |||
287 | [#29641]: https://github.com/rust-lang/rust/issues/29641 | ||
288 | |||
289 | See also [`box_syntax`](box-syntax.md) | ||
290 | |||
291 | ------------------------ | ||
292 | |||
293 | Box patterns let you match on `Box<T>`s: | ||
294 | |||
295 | |||
296 | ```rust | ||
297 | #![feature(box_patterns)] | ||
298 | 482 | ||
299 | fn main() { | 483 | pub const FEATURES: &[Lint] = &[ |
300 | let b = Some(Box::new(5)); | 484 | Lint { |
301 | match b { | ||
302 | Some(box n) if n < 0 => { | ||
303 | println!("Box contains negative number {}", n); | ||
304 | }, | ||
305 | Some(box n) if n >= 0 => { | ||
306 | println!("Box contains non-negative number {}", n); | ||
307 | }, | ||
308 | None => { | ||
309 | println!("No box"); | ||
310 | }, | ||
311 | _ => unreachable!() | ||
312 | } | ||
313 | } | ||
314 | ``` | ||
315 | "##, | ||
316 | }, | ||
317 | LintCompletion { | ||
318 | label: "abi_c_cmse_nonsecure_call", | 485 | label: "abi_c_cmse_nonsecure_call", |
319 | description: r##"# `abi_c_cmse_nonsecure_call` | 486 | description: r##"# `abi_c_cmse_nonsecure_call` |
320 | 487 | ||
@@ -406,1682 +573,7 @@ call_nonsecure_function: | |||
406 | ``` | 573 | ``` |
407 | "##, | 574 | "##, |
408 | }, | 575 | }, |
409 | LintCompletion { | 576 | Lint { |
410 | label: "member_constraints", | ||
411 | description: r##"# `member_constraints` | ||
412 | |||
413 | The tracking issue for this feature is: [#61997] | ||
414 | |||
415 | [#61997]: https://github.com/rust-lang/rust/issues/61997 | ||
416 | |||
417 | ------------------------ | ||
418 | |||
419 | The `member_constraints` feature gate lets you use `impl Trait` syntax with | ||
420 | multiple unrelated lifetime parameters. | ||
421 | |||
422 | A simple example is: | ||
423 | |||
424 | ```rust | ||
425 | #![feature(member_constraints)] | ||
426 | |||
427 | trait Trait<'a, 'b> { } | ||
428 | impl<T> Trait<'_, '_> for T {} | ||
429 | |||
430 | fn foo<'a, 'b>(x: &'a u32, y: &'b u32) -> impl Trait<'a, 'b> { | ||
431 | (x, y) | ||
432 | } | ||
433 | |||
434 | fn main() { } | ||
435 | ``` | ||
436 | |||
437 | Without the `member_constraints` feature gate, the above example is an | ||
438 | error because both `'a` and `'b` appear in the impl Trait bounds, but | ||
439 | neither outlives the other. | ||
440 | "##, | ||
441 | }, | ||
442 | LintCompletion { | ||
443 | label: "allocator_internals", | ||
444 | description: r##"# `allocator_internals` | ||
445 | |||
446 | This feature does not have a tracking issue, it is an unstable implementation | ||
447 | detail of the `global_allocator` feature not intended for use outside the | ||
448 | compiler. | ||
449 | |||
450 | ------------------------ | ||
451 | "##, | ||
452 | }, | ||
453 | LintCompletion { | ||
454 | label: "cfg_sanitize", | ||
455 | description: r##"# `cfg_sanitize` | ||
456 | |||
457 | The tracking issue for this feature is: [#39699] | ||
458 | |||
459 | [#39699]: https://github.com/rust-lang/rust/issues/39699 | ||
460 | |||
461 | ------------------------ | ||
462 | |||
463 | The `cfg_sanitize` feature makes it possible to execute different code | ||
464 | depending on whether a particular sanitizer is enabled or not. | ||
465 | |||
466 | ## Examples | ||
467 | |||
468 | ```rust | ||
469 | #![feature(cfg_sanitize)] | ||
470 | |||
471 | #[cfg(sanitize = "thread")] | ||
472 | fn a() { | ||
473 | // ... | ||
474 | } | ||
475 | |||
476 | #[cfg(not(sanitize = "thread"))] | ||
477 | fn a() { | ||
478 | // ... | ||
479 | } | ||
480 | |||
481 | fn b() { | ||
482 | if cfg!(sanitize = "leak") { | ||
483 | // ... | ||
484 | } else { | ||
485 | // ... | ||
486 | } | ||
487 | } | ||
488 | ``` | ||
489 | "##, | ||
490 | }, | ||
491 | LintCompletion { | ||
492 | label: "cfg_panic", | ||
493 | description: r##"# `cfg_panic` | ||
494 | |||
495 | The tracking issue for this feature is: [#77443] | ||
496 | |||
497 | [#77443]: https://github.com/rust-lang/rust/issues/77443 | ||
498 | |||
499 | ------------------------ | ||
500 | |||
501 | The `cfg_panic` feature makes it possible to execute different code | ||
502 | depending on the panic strategy. | ||
503 | |||
504 | Possible values at the moment are `"unwind"` or `"abort"`, although | ||
505 | it is possible that new panic strategies may be added to Rust in the | ||
506 | future. | ||
507 | |||
508 | ## Examples | ||
509 | |||
510 | ```rust | ||
511 | #![feature(cfg_panic)] | ||
512 | |||
513 | #[cfg(panic = "unwind")] | ||
514 | fn a() { | ||
515 | // ... | ||
516 | } | ||
517 | |||
518 | #[cfg(not(panic = "unwind"))] | ||
519 | fn a() { | ||
520 | // ... | ||
521 | } | ||
522 | |||
523 | fn b() { | ||
524 | if cfg!(panic = "abort") { | ||
525 | // ... | ||
526 | } else { | ||
527 | // ... | ||
528 | } | ||
529 | } | ||
530 | ``` | ||
531 | "##, | ||
532 | }, | ||
533 | LintCompletion { | ||
534 | label: "ffi_pure", | ||
535 | description: r##"# `ffi_pure` | ||
536 | |||
537 | The tracking issue for this feature is: [#58329] | ||
538 | |||
539 | ------ | ||
540 | |||
541 | The `#[ffi_pure]` attribute applies clang's `pure` attribute to foreign | ||
542 | functions declarations. | ||
543 | |||
544 | That is, `#[ffi_pure]` functions shall have no effects except for its return | ||
545 | value, which shall not change across two consecutive function calls with | ||
546 | the same parameters. | ||
547 | |||
548 | Applying the `#[ffi_pure]` attribute to a function that violates these | ||
549 | requirements is undefined behavior. | ||
550 | |||
551 | This attribute enables Rust to perform common optimizations, like sub-expression | ||
552 | elimination and loop optimizations. Some common examples of pure functions are | ||
553 | `strlen` or `memcmp`. | ||
554 | |||
555 | These optimizations are only applicable when the compiler can prove that no | ||
556 | program state observable by the `#[ffi_pure]` function has changed between calls | ||
557 | of the function, which could alter the result. See also the `#[ffi_const]` | ||
558 | attribute, which provides stronger guarantees regarding the allowable behavior | ||
559 | of a function, enabling further optimization. | ||
560 | |||
561 | ## Pitfalls | ||
562 | |||
563 | A `#[ffi_pure]` function can read global memory through the function | ||
564 | parameters (e.g. pointers), globals, etc. `#[ffi_pure]` functions are not | ||
565 | referentially-transparent, and are therefore more relaxed than `#[ffi_const]` | ||
566 | functions. | ||
567 | |||
568 | However, accessing global memory through volatile or atomic reads can violate the | ||
569 | requirement that two consecutive function calls shall return the same value. | ||
570 | |||
571 | A `pure` function that returns unit has no effect on the abstract machine's | ||
572 | state. | ||
573 | |||
574 | A `#[ffi_pure]` function must not diverge, neither via a side effect (e.g. a | ||
575 | call to `abort`) nor by infinite loops. | ||
576 | |||
577 | When translating C headers to Rust FFI, it is worth verifying for which targets | ||
578 | the `pure` attribute is enabled in those headers, and using the appropriate | ||
579 | `cfg` macros in the Rust side to match those definitions. While the semantics of | ||
580 | `pure` are implemented identically by many C and C++ compilers, e.g., clang, | ||
581 | [GCC], [ARM C/C++ compiler], [IBM ILE C/C++], etc. they are not necessarily | ||
582 | implemented in this way on all of them. It is therefore also worth verifying | ||
583 | that the semantics of the C toolchain used to compile the binary being linked | ||
584 | against are compatible with those of the `#[ffi_pure]`. | ||
585 | |||
586 | |||
587 | [#58329]: https://github.com/rust-lang/rust/issues/58329 | ||
588 | [ARM C/C++ compiler]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0491c/Cacigdac.html | ||
589 | [GCC]: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-pure-function-attribute | ||
590 | [IBM ILE C/C++]: https://www.ibm.com/support/knowledgecenter/fr/ssw_ibm_i_71/rzarg/fn_attrib_pure.htm | ||
591 | "##, | ||
592 | }, | ||
593 | LintCompletion { | ||
594 | label: "repr128", | ||
595 | description: r##"# `repr128` | ||
596 | |||
597 | The tracking issue for this feature is: [#56071] | ||
598 | |||
599 | [#56071]: https://github.com/rust-lang/rust/issues/56071 | ||
600 | |||
601 | ------------------------ | ||
602 | |||
603 | The `repr128` feature adds support for `#[repr(u128)]` on `enum`s. | ||
604 | |||
605 | ```rust | ||
606 | #![feature(repr128)] | ||
607 | |||
608 | #[repr(u128)] | ||
609 | enum Foo { | ||
610 | Bar(u64), | ||
611 | } | ||
612 | ``` | ||
613 | "##, | ||
614 | }, | ||
615 | LintCompletion { | ||
616 | label: "generators", | ||
617 | description: r##"# `generators` | ||
618 | |||
619 | The tracking issue for this feature is: [#43122] | ||
620 | |||
621 | [#43122]: https://github.com/rust-lang/rust/issues/43122 | ||
622 | |||
623 | ------------------------ | ||
624 | |||
625 | The `generators` feature gate in Rust allows you to define generator or | ||
626 | coroutine literals. A generator is a "resumable function" that syntactically | ||
627 | resembles a closure but compiles to much different semantics in the compiler | ||
628 | itself. The primary feature of a generator is that it can be suspended during | ||
629 | execution to be resumed at a later date. Generators use the `yield` keyword to | ||
630 | "return", and then the caller can `resume` a generator to resume execution just | ||
631 | after the `yield` keyword. | ||
632 | |||
633 | Generators are an extra-unstable feature in the compiler right now. Added in | ||
634 | [RFC 2033] they're mostly intended right now as a information/constraint | ||
635 | gathering phase. The intent is that experimentation can happen on the nightly | ||
636 | compiler before actual stabilization. A further RFC will be required to | ||
637 | stabilize generators/coroutines and will likely contain at least a few small | ||
638 | tweaks to the overall design. | ||
639 | |||
640 | [RFC 2033]: https://github.com/rust-lang/rfcs/pull/2033 | ||
641 | |||
642 | A syntactical example of a generator is: | ||
643 | |||
644 | ```rust | ||
645 | #![feature(generators, generator_trait)] | ||
646 | |||
647 | use std::ops::{Generator, GeneratorState}; | ||
648 | use std::pin::Pin; | ||
649 | |||
650 | fn main() { | ||
651 | let mut generator = || { | ||
652 | yield 1; | ||
653 | return "foo" | ||
654 | }; | ||
655 | |||
656 | match Pin::new(&mut generator).resume(()) { | ||
657 | GeneratorState::Yielded(1) => {} | ||
658 | _ => panic!("unexpected value from resume"), | ||
659 | } | ||
660 | match Pin::new(&mut generator).resume(()) { | ||
661 | GeneratorState::Complete("foo") => {} | ||
662 | _ => panic!("unexpected value from resume"), | ||
663 | } | ||
664 | } | ||
665 | ``` | ||
666 | |||
667 | Generators are closure-like literals which can contain a `yield` statement. The | ||
668 | `yield` statement takes an optional expression of a value to yield out of the | ||
669 | generator. All generator literals implement the `Generator` trait in the | ||
670 | `std::ops` module. The `Generator` trait has one main method, `resume`, which | ||
671 | resumes execution of the generator at the previous suspension point. | ||
672 | |||
673 | An example of the control flow of generators is that the following example | ||
674 | prints all numbers in order: | ||
675 | |||
676 | ```rust | ||
677 | #![feature(generators, generator_trait)] | ||
678 | |||
679 | use std::ops::Generator; | ||
680 | use std::pin::Pin; | ||
681 | |||
682 | fn main() { | ||
683 | let mut generator = || { | ||
684 | println!("2"); | ||
685 | yield; | ||
686 | println!("4"); | ||
687 | }; | ||
688 | |||
689 | println!("1"); | ||
690 | Pin::new(&mut generator).resume(()); | ||
691 | println!("3"); | ||
692 | Pin::new(&mut generator).resume(()); | ||
693 | println!("5"); | ||
694 | } | ||
695 | ``` | ||
696 | |||
697 | At this time the main intended use case of generators is an implementation | ||
698 | primitive for async/await syntax, but generators will likely be extended to | ||
699 | ergonomic implementations of iterators and other primitives in the future. | ||
700 | Feedback on the design and usage is always appreciated! | ||
701 | |||
702 | ### The `Generator` trait | ||
703 | |||
704 | The `Generator` trait in `std::ops` currently looks like: | ||
705 | |||
706 | ```rust | ||
707 | # #![feature(arbitrary_self_types, generator_trait)] | ||
708 | # use std::ops::GeneratorState; | ||
709 | # use std::pin::Pin; | ||
710 | |||
711 | pub trait Generator<R = ()> { | ||
712 | type Yield; | ||
713 | type Return; | ||
714 | fn resume(self: Pin<&mut Self>, resume: R) -> GeneratorState<Self::Yield, Self::Return>; | ||
715 | } | ||
716 | ``` | ||
717 | |||
718 | The `Generator::Yield` type is the type of values that can be yielded with the | ||
719 | `yield` statement. The `Generator::Return` type is the returned type of the | ||
720 | generator. This is typically the last expression in a generator's definition or | ||
721 | any value passed to `return` in a generator. The `resume` function is the entry | ||
722 | point for executing the `Generator` itself. | ||
723 | |||
724 | The return value of `resume`, `GeneratorState`, looks like: | ||
725 | |||
726 | ```rust | ||
727 | pub enum GeneratorState<Y, R> { | ||
728 | Yielded(Y), | ||
729 | Complete(R), | ||
730 | } | ||
731 | ``` | ||
732 | |||
733 | The `Yielded` variant indicates that the generator can later be resumed. This | ||
734 | corresponds to a `yield` point in a generator. The `Complete` variant indicates | ||
735 | that the generator is complete and cannot be resumed again. Calling `resume` | ||
736 | after a generator has returned `Complete` will likely result in a panic of the | ||
737 | program. | ||
738 | |||
739 | ### Closure-like semantics | ||
740 | |||
741 | The closure-like syntax for generators alludes to the fact that they also have | ||
742 | closure-like semantics. Namely: | ||
743 | |||
744 | * When created, a generator executes no code. A closure literal does not | ||
745 | actually execute any of the closure's code on construction, and similarly a | ||
746 | generator literal does not execute any code inside the generator when | ||
747 | constructed. | ||
748 | |||
749 | * Generators can capture outer variables by reference or by move, and this can | ||
750 | be tweaked with the `move` keyword at the beginning of the closure. Like | ||
751 | closures all generators will have an implicit environment which is inferred by | ||
752 | the compiler. Outer variables can be moved into a generator for use as the | ||
753 | generator progresses. | ||
754 | |||
755 | * Generator literals produce a value with a unique type which implements the | ||
756 | `std::ops::Generator` trait. This allows actual execution of the generator | ||
757 | through the `Generator::resume` method as well as also naming it in return | ||
758 | types and such. | ||
759 | |||
760 | * Traits like `Send` and `Sync` are automatically implemented for a `Generator` | ||
761 | depending on the captured variables of the environment. Unlike closures, | ||
762 | generators also depend on variables live across suspension points. This means | ||
763 | that although the ambient environment may be `Send` or `Sync`, the generator | ||
764 | itself may not be due to internal variables live across `yield` points being | ||
765 | not-`Send` or not-`Sync`. Note that generators do | ||
766 | not implement traits like `Copy` or `Clone` automatically. | ||
767 | |||
768 | * Whenever a generator is dropped it will drop all captured environment | ||
769 | variables. | ||
770 | |||
771 | ### Generators as state machines | ||
772 | |||
773 | In the compiler, generators are currently compiled as state machines. Each | ||
774 | `yield` expression will correspond to a different state that stores all live | ||
775 | variables over that suspension point. Resumption of a generator will dispatch on | ||
776 | the current state and then execute internally until a `yield` is reached, at | ||
777 | which point all state is saved off in the generator and a value is returned. | ||
778 | |||
779 | Let's take a look at an example to see what's going on here: | ||
780 | |||
781 | ```rust | ||
782 | #![feature(generators, generator_trait)] | ||
783 | |||
784 | use std::ops::Generator; | ||
785 | use std::pin::Pin; | ||
786 | |||
787 | fn main() { | ||
788 | let ret = "foo"; | ||
789 | let mut generator = move || { | ||
790 | yield 1; | ||
791 | return ret | ||
792 | }; | ||
793 | |||
794 | Pin::new(&mut generator).resume(()); | ||
795 | Pin::new(&mut generator).resume(()); | ||
796 | } | ||
797 | ``` | ||
798 | |||
799 | This generator literal will compile down to something similar to: | ||
800 | |||
801 | ```rust | ||
802 | #![feature(arbitrary_self_types, generators, generator_trait)] | ||
803 | |||
804 | use std::ops::{Generator, GeneratorState}; | ||
805 | use std::pin::Pin; | ||
806 | |||
807 | fn main() { | ||
808 | let ret = "foo"; | ||
809 | let mut generator = { | ||
810 | enum __Generator { | ||
811 | Start(&'static str), | ||
812 | Yield1(&'static str), | ||
813 | Done, | ||
814 | } | ||
815 | |||
816 | impl Generator for __Generator { | ||
817 | type Yield = i32; | ||
818 | type Return = &'static str; | ||
819 | |||
820 | fn resume(mut self: Pin<&mut Self>, resume: ()) -> GeneratorState<i32, &'static str> { | ||
821 | use std::mem; | ||
822 | match mem::replace(&mut *self, __Generator::Done) { | ||
823 | __Generator::Start(s) => { | ||
824 | *self = __Generator::Yield1(s); | ||
825 | GeneratorState::Yielded(1) | ||
826 | } | ||
827 | |||
828 | __Generator::Yield1(s) => { | ||
829 | *self = __Generator::Done; | ||
830 | GeneratorState::Complete(s) | ||
831 | } | ||
832 | |||
833 | __Generator::Done => { | ||
834 | panic!("generator resumed after completion") | ||
835 | } | ||
836 | } | ||
837 | } | ||
838 | } | ||
839 | |||
840 | __Generator::Start(ret) | ||
841 | }; | ||
842 | |||
843 | Pin::new(&mut generator).resume(()); | ||
844 | Pin::new(&mut generator).resume(()); | ||
845 | } | ||
846 | ``` | ||
847 | |||
848 | Notably here we can see that the compiler is generating a fresh type, | ||
849 | `__Generator` in this case. This type has a number of states (represented here | ||
850 | as an `enum`) corresponding to each of the conceptual states of the generator. | ||
851 | At the beginning we're closing over our outer variable `foo` and then that | ||
852 | variable is also live over the `yield` point, so it's stored in both states. | ||
853 | |||
854 | When the generator starts it'll immediately yield 1, but it saves off its state | ||
855 | just before it does so indicating that it has reached the yield point. Upon | ||
856 | resuming again we'll execute the `return ret` which returns the `Complete` | ||
857 | state. | ||
858 | |||
859 | Here we can also note that the `Done` state, if resumed, panics immediately as | ||
860 | it's invalid to resume a completed generator. It's also worth noting that this | ||
861 | is just a rough desugaring, not a normative specification for what the compiler | ||
862 | does. | ||
863 | "##, | ||
864 | }, | ||
865 | LintCompletion { | ||
866 | label: "non_ascii_idents", | ||
867 | description: r##"# `non_ascii_idents` | ||
868 | |||
869 | The tracking issue for this feature is: [#55467] | ||
870 | |||
871 | [#55467]: https://github.com/rust-lang/rust/issues/55467 | ||
872 | |||
873 | ------------------------ | ||
874 | |||
875 | The `non_ascii_idents` feature adds support for non-ASCII identifiers. | ||
876 | |||
877 | ## Examples | ||
878 | |||
879 | ```rust | ||
880 | #![feature(non_ascii_idents)] | ||
881 | |||
882 | const ε: f64 = 0.00001f64; | ||
883 | const Π: f64 = 3.14f64; | ||
884 | ``` | ||
885 | |||
886 | ## Changes to the language reference | ||
887 | |||
888 | > **<sup>Lexer:<sup>**\ | ||
889 | > IDENTIFIER :\ | ||
890 | > XID_start XID_continue<sup>\*</sup>\ | ||
891 | > | `_` XID_continue<sup>+</sup> | ||
892 | |||
893 | An identifier is any nonempty Unicode string of the following form: | ||
894 | |||
895 | Either | ||
896 | |||
897 | * The first character has property [`XID_start`] | ||
898 | * The remaining characters have property [`XID_continue`] | ||
899 | |||
900 | Or | ||
901 | |||
902 | * The first character is `_` | ||
903 | * The identifier is more than one character, `_` alone is not an identifier | ||
904 | * The remaining characters have property [`XID_continue`] | ||
905 | |||
906 | that does _not_ occur in the set of [strict keywords]. | ||
907 | |||
908 | > **Note**: [`XID_start`] and [`XID_continue`] as character properties cover the | ||
909 | > character ranges used to form the more familiar C and Java language-family | ||
910 | > identifiers. | ||
911 | |||
912 | [`XID_start`]: http://unicode.org/cldr/utility/list-unicodeset.jsp?a=%5B%3AXID_Start%3A%5D&abb=on&g=&i= | ||
913 | [`XID_continue`]: http://unicode.org/cldr/utility/list-unicodeset.jsp?a=%5B%3AXID_Continue%3A%5D&abb=on&g=&i= | ||
914 | [strict keywords]: ../../reference/keywords.md#strict-keywords | ||
915 | "##, | ||
916 | }, | ||
917 | LintCompletion { | ||
918 | label: "compiler_builtins", | ||
919 | description: r##"# `compiler_builtins` | ||
920 | |||
921 | This feature is internal to the Rust compiler and is not intended for general use. | ||
922 | |||
923 | ------------------------ | ||
924 | "##, | ||
925 | }, | ||
926 | LintCompletion { | ||
927 | label: "or_patterns", | ||
928 | description: r##"# `or_patterns` | ||
929 | |||
930 | The tracking issue for this feature is: [#54883] | ||
931 | |||
932 | [#54883]: https://github.com/rust-lang/rust/issues/54883 | ||
933 | |||
934 | ------------------------ | ||
935 | |||
936 | The `or_pattern` language feature allows `|` to be arbitrarily nested within | ||
937 | a pattern, for example, `Some(A(0) | B(1 | 2))` becomes a valid pattern. | ||
938 | |||
939 | ## Examples | ||
940 | |||
941 | ```rust,no_run | ||
942 | #![feature(or_patterns)] | ||
943 | |||
944 | pub enum Foo { | ||
945 | Bar, | ||
946 | Baz, | ||
947 | Quux, | ||
948 | } | ||
949 | |||
950 | pub fn example(maybe_foo: Option<Foo>) { | ||
951 | match maybe_foo { | ||
952 | Some(Foo::Bar | Foo::Baz) => { | ||
953 | println!("The value contained `Bar` or `Baz`"); | ||
954 | } | ||
955 | Some(_) => { | ||
956 | println!("The value did not contain `Bar` or `Baz`"); | ||
957 | } | ||
958 | None => { | ||
959 | println!("The value was `None`"); | ||
960 | } | ||
961 | } | ||
962 | } | ||
963 | ``` | ||
964 | "##, | ||
965 | }, | ||
966 | LintCompletion { | ||
967 | label: "negative_impls", | ||
968 | description: r##"# `negative_impls` | ||
969 | |||
970 | The tracking issue for this feature is [#68318]. | ||
971 | |||
972 | [#68318]: https://github.com/rust-lang/rust/issues/68318 | ||
973 | |||
974 | ---- | ||
975 | |||
976 | With the feature gate `negative_impls`, you can write negative impls as well as positive ones: | ||
977 | |||
978 | ```rust | ||
979 | #![feature(negative_impls)] | ||
980 | trait DerefMut { } | ||
981 | impl<T: ?Sized> !DerefMut for &T { } | ||
982 | ``` | ||
983 | |||
984 | Negative impls indicate a semver guarantee that the given trait will not be implemented for the given types. Negative impls play an additional purpose for auto traits, described below. | ||
985 | |||
986 | Negative impls have the following characteristics: | ||
987 | |||
988 | * They do not have any items. | ||
989 | * They must obey the orphan rules as if they were a positive impl. | ||
990 | * They cannot "overlap" with any positive impls. | ||
991 | |||
992 | ## Semver interaction | ||
993 | |||
994 | It is a breaking change to remove a negative impl. Negative impls are a commitment not to implement the given trait for the named types. | ||
995 | |||
996 | ## Orphan and overlap rules | ||
997 | |||
998 | Negative impls must obey the same orphan rules as a positive impl. This implies you cannot add a negative impl for types defined in upstream crates and so forth. | ||
999 | |||
1000 | Similarly, negative impls cannot overlap with positive impls, again using the same "overlap" check that we ordinarily use to determine if two impls overlap. (Note that positive impls typically cannot overlap with one another either, except as permitted by specialization.) | ||
1001 | |||
1002 | ## Interaction with auto traits | ||
1003 | |||
1004 | Declaring a negative impl `impl !SomeAutoTrait for SomeType` for an | ||
1005 | auto-trait serves two purposes: | ||
1006 | |||
1007 | * as with any trait, it declares that `SomeType` will never implement `SomeAutoTrait`; | ||
1008 | * it disables the automatic `SomeType: SomeAutoTrait` impl that would otherwise have been generated. | ||
1009 | |||
1010 | Note that, at present, there is no way to indicate that a given type | ||
1011 | does not implement an auto trait *but that it may do so in the | ||
1012 | future*. For ordinary types, this is done by simply not declaring any | ||
1013 | impl at all, but that is not an option for auto traits. A workaround | ||
1014 | is that one could embed a marker type as one of the fields, where the | ||
1015 | marker type is `!AutoTrait`. | ||
1016 | |||
1017 | ## Immediate uses | ||
1018 | |||
1019 | Negative impls are used to declare that `&T: !DerefMut` and `&mut T: !Clone`, as required to fix the soundness of `Pin` described in [#66544](https://github.com/rust-lang/rust/issues/66544). | ||
1020 | |||
1021 | This serves two purposes: | ||
1022 | |||
1023 | * For proving the correctness of unsafe code, we can use that impl as evidence that no `DerefMut` or `Clone` impl exists. | ||
1024 | * It prevents downstream crates from creating such impls. | ||
1025 | "##, | ||
1026 | }, | ||
1027 | LintCompletion { | ||
1028 | label: "cmse_nonsecure_entry", | ||
1029 | description: r##"# `cmse_nonsecure_entry` | ||
1030 | |||
1031 | The tracking issue for this feature is: [#75835] | ||
1032 | |||
1033 | [#75835]: https://github.com/rust-lang/rust/issues/75835 | ||
1034 | |||
1035 | ------------------------ | ||
1036 | |||
1037 | The [TrustZone-M | ||
1038 | feature](https://developer.arm.com/documentation/100690/latest/) is available | ||
1039 | for targets with the Armv8-M architecture profile (`thumbv8m` in their target | ||
1040 | name). | ||
1041 | LLVM, the Rust compiler and the linker are providing | ||
1042 | [support](https://developer.arm.com/documentation/ecm0359818/latest/) for the | ||
1043 | TrustZone-M feature. | ||
1044 | |||
1045 | One of the things provided, with this unstable feature, is the | ||
1046 | `cmse_nonsecure_entry` attribute. This attribute marks a Secure function as an | ||
1047 | entry function (see [section | ||
1048 | 5.4](https://developer.arm.com/documentation/ecm0359818/latest/) for details). | ||
1049 | With this attribute, the compiler will do the following: | ||
1050 | * add a special symbol on the function which is the `__acle_se_` prefix and the | ||
1051 | standard function name | ||
1052 | * constrain the number of parameters to avoid using the Non-Secure stack | ||
1053 | * before returning from the function, clear registers that might contain Secure | ||
1054 | information | ||
1055 | * use the `BXNS` instruction to return | ||
1056 | |||
1057 | Because the stack can not be used to pass parameters, there will be compilation | ||
1058 | errors if: | ||
1059 | * the total size of all parameters is too big (for example more than four 32 | ||
1060 | bits integers) | ||
1061 | * the entry function is not using a C ABI | ||
1062 | |||
1063 | The special symbol `__acle_se_` will be used by the linker to generate a secure | ||
1064 | gateway veneer. | ||
1065 | |||
1066 | <!-- NOTE(ignore) this example is specific to thumbv8m targets --> | ||
1067 | |||
1068 | ``` rust,ignore | ||
1069 | #![feature(cmse_nonsecure_entry)] | ||
1070 | |||
1071 | #[no_mangle] | ||
1072 | #[cmse_nonsecure_entry] | ||
1073 | pub extern "C" fn entry_function(input: u32) -> u32 { | ||
1074 | input + 6 | ||
1075 | } | ||
1076 | ``` | ||
1077 | |||
1078 | ``` text | ||
1079 | $ rustc --emit obj --crate-type lib --target thumbv8m.main-none-eabi function.rs | ||
1080 | $ arm-none-eabi-objdump -D function.o | ||
1081 | |||
1082 | 00000000 <entry_function>: | ||
1083 | 0: b580 push {r7, lr} | ||
1084 | 2: 466f mov r7, sp | ||
1085 | 4: b082 sub sp, #8 | ||
1086 | 6: 9001 str r0, [sp, #4] | ||
1087 | 8: 1d81 adds r1, r0, #6 | ||
1088 | a: 460a mov r2, r1 | ||
1089 | c: 4281 cmp r1, r0 | ||
1090 | e: 9200 str r2, [sp, #0] | ||
1091 | 10: d30b bcc.n 2a <entry_function+0x2a> | ||
1092 | 12: e7ff b.n 14 <entry_function+0x14> | ||
1093 | 14: 9800 ldr r0, [sp, #0] | ||
1094 | 16: b002 add sp, #8 | ||
1095 | 18: e8bd 4080 ldmia.w sp!, {r7, lr} | ||
1096 | 1c: 4671 mov r1, lr | ||
1097 | 1e: 4672 mov r2, lr | ||
1098 | 20: 4673 mov r3, lr | ||
1099 | 22: 46f4 mov ip, lr | ||
1100 | 24: f38e 8800 msr CPSR_f, lr | ||
1101 | 28: 4774 bxns lr | ||
1102 | 2a: f240 0000 movw r0, #0 | ||
1103 | 2e: f2c0 0000 movt r0, #0 | ||
1104 | 32: f240 0200 movw r2, #0 | ||
1105 | 36: f2c0 0200 movt r2, #0 | ||
1106 | 3a: 211c movs r1, #28 | ||
1107 | 3c: f7ff fffe bl 0 <_ZN4core9panicking5panic17h5c028258ca2fb3f5E> | ||
1108 | 40: defe udf #254 ; 0xfe | ||
1109 | ``` | ||
1110 | "##, | ||
1111 | }, | ||
1112 | LintCompletion { | ||
1113 | label: "plugin", | ||
1114 | description: r##"# `plugin` | ||
1115 | |||
1116 | The tracking issue for this feature is: [#29597] | ||
1117 | |||
1118 | [#29597]: https://github.com/rust-lang/rust/issues/29597 | ||
1119 | |||
1120 | |||
1121 | This feature is part of "compiler plugins." It will often be used with the | ||
1122 | [`plugin_registrar`] and `rustc_private` features. | ||
1123 | |||
1124 | [`plugin_registrar`]: plugin-registrar.md | ||
1125 | |||
1126 | ------------------------ | ||
1127 | |||
1128 | `rustc` can load compiler plugins, which are user-provided libraries that | ||
1129 | extend the compiler's behavior with new lint checks, etc. | ||
1130 | |||
1131 | A plugin is a dynamic library crate with a designated *registrar* function that | ||
1132 | registers extensions with `rustc`. Other crates can load these extensions using | ||
1133 | the crate attribute `#![plugin(...)]`. See the | ||
1134 | `rustc_driver::plugin` documentation for more about the | ||
1135 | mechanics of defining and loading a plugin. | ||
1136 | |||
1137 | In the vast majority of cases, a plugin should *only* be used through | ||
1138 | `#![plugin]` and not through an `extern crate` item. Linking a plugin would | ||
1139 | pull in all of librustc_ast and librustc as dependencies of your crate. This is | ||
1140 | generally unwanted unless you are building another plugin. | ||
1141 | |||
1142 | The usual practice is to put compiler plugins in their own crate, separate from | ||
1143 | any `macro_rules!` macros or ordinary Rust code meant to be used by consumers | ||
1144 | of a library. | ||
1145 | |||
1146 | # Lint plugins | ||
1147 | |||
1148 | Plugins can extend [Rust's lint | ||
1149 | infrastructure](../../reference/attributes/diagnostics.md#lint-check-attributes) with | ||
1150 | additional checks for code style, safety, etc. Now let's write a plugin | ||
1151 | [`lint-plugin-test.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui-fulldeps/auxiliary/lint-plugin-test.rs) | ||
1152 | that warns about any item named `lintme`. | ||
1153 | |||
1154 | ```rust,ignore (requires-stage-2) | ||
1155 | #![feature(plugin_registrar)] | ||
1156 | #![feature(box_syntax, rustc_private)] | ||
1157 | |||
1158 | extern crate rustc_ast; | ||
1159 | |||
1160 | // Load rustc as a plugin to get macros | ||
1161 | extern crate rustc_driver; | ||
1162 | #[macro_use] | ||
1163 | extern crate rustc_lint; | ||
1164 | #[macro_use] | ||
1165 | extern crate rustc_session; | ||
1166 | |||
1167 | use rustc_driver::plugin::Registry; | ||
1168 | use rustc_lint::{EarlyContext, EarlyLintPass, LintArray, LintContext, LintPass}; | ||
1169 | use rustc_ast::ast; | ||
1170 | declare_lint!(TEST_LINT, Warn, "Warn about items named 'lintme'"); | ||
1171 | |||
1172 | declare_lint_pass!(Pass => [TEST_LINT]); | ||
1173 | |||
1174 | impl EarlyLintPass for Pass { | ||
1175 | fn check_item(&mut self, cx: &EarlyContext, it: &ast::Item) { | ||
1176 | if it.ident.name.as_str() == "lintme" { | ||
1177 | cx.lint(TEST_LINT, |lint| { | ||
1178 | lint.build("item is named 'lintme'").set_span(it.span).emit() | ||
1179 | }); | ||
1180 | } | ||
1181 | } | ||
1182 | } | ||
1183 | |||
1184 | #[plugin_registrar] | ||
1185 | pub fn plugin_registrar(reg: &mut Registry) { | ||
1186 | reg.lint_store.register_lints(&[&TEST_LINT]); | ||
1187 | reg.lint_store.register_early_pass(|| box Pass); | ||
1188 | } | ||
1189 | ``` | ||
1190 | |||
1191 | Then code like | ||
1192 | |||
1193 | ```rust,ignore (requires-plugin) | ||
1194 | #![feature(plugin)] | ||
1195 | #![plugin(lint_plugin_test)] | ||
1196 | |||
1197 | fn lintme() { } | ||
1198 | ``` | ||
1199 | |||
1200 | will produce a compiler warning: | ||
1201 | |||
1202 | ```txt | ||
1203 | foo.rs:4:1: 4:16 warning: item is named 'lintme', #[warn(test_lint)] on by default | ||
1204 | foo.rs:4 fn lintme() { } | ||
1205 | ^~~~~~~~~~~~~~~ | ||
1206 | ``` | ||
1207 | |||
1208 | The components of a lint plugin are: | ||
1209 | |||
1210 | * one or more `declare_lint!` invocations, which define static `Lint` structs; | ||
1211 | |||
1212 | * a struct holding any state needed by the lint pass (here, none); | ||
1213 | |||
1214 | * a `LintPass` | ||
1215 | implementation defining how to check each syntax element. A single | ||
1216 | `LintPass` may call `span_lint` for several different `Lint`s, but should | ||
1217 | register them all through the `get_lints` method. | ||
1218 | |||
1219 | Lint passes are syntax traversals, but they run at a late stage of compilation | ||
1220 | where type information is available. `rustc`'s [built-in | ||
1221 | lints](https://github.com/rust-lang/rust/blob/master/src/librustc_session/lint/builtin.rs) | ||
1222 | mostly use the same infrastructure as lint plugins, and provide examples of how | ||
1223 | to access type information. | ||
1224 | |||
1225 | Lints defined by plugins are controlled by the usual [attributes and compiler | ||
1226 | flags](../../reference/attributes/diagnostics.md#lint-check-attributes), e.g. | ||
1227 | `#[allow(test_lint)]` or `-A test-lint`. These identifiers are derived from the | ||
1228 | first argument to `declare_lint!`, with appropriate case and punctuation | ||
1229 | conversion. | ||
1230 | |||
1231 | You can run `rustc -W help foo.rs` to see a list of lints known to `rustc`, | ||
1232 | including those provided by plugins loaded by `foo.rs`. | ||
1233 | "##, | ||
1234 | }, | ||
1235 | LintCompletion { | ||
1236 | label: "intrinsics", | ||
1237 | description: r##"# `intrinsics` | ||
1238 | |||
1239 | The tracking issue for this feature is: None. | ||
1240 | |||
1241 | Intrinsics are never intended to be stable directly, but intrinsics are often | ||
1242 | exported in some sort of stable manner. Prefer using the stable interfaces to | ||
1243 | the intrinsic directly when you can. | ||
1244 | |||
1245 | ------------------------ | ||
1246 | |||
1247 | |||
1248 | These are imported as if they were FFI functions, with the special | ||
1249 | `rust-intrinsic` ABI. For example, if one was in a freestanding | ||
1250 | context, but wished to be able to `transmute` between types, and | ||
1251 | perform efficient pointer arithmetic, one would import those functions | ||
1252 | via a declaration like | ||
1253 | |||
1254 | ```rust | ||
1255 | #![feature(intrinsics)] | ||
1256 | # fn main() {} | ||
1257 | |||
1258 | extern "rust-intrinsic" { | ||
1259 | fn transmute<T, U>(x: T) -> U; | ||
1260 | |||
1261 | fn offset<T>(dst: *const T, offset: isize) -> *const T; | ||
1262 | } | ||
1263 | ``` | ||
1264 | |||
1265 | As with any other FFI functions, these are always `unsafe` to call. | ||
1266 | "##, | ||
1267 | }, | ||
1268 | LintCompletion { | ||
1269 | label: "rustc_attrs", | ||
1270 | description: r##"# `rustc_attrs` | ||
1271 | |||
1272 | This feature has no tracking issue, and is therefore internal to | ||
1273 | the compiler, not being intended for general use. | ||
1274 | |||
1275 | Note: `rustc_attrs` enables many rustc-internal attributes and this page | ||
1276 | only discuss a few of them. | ||
1277 | |||
1278 | ------------------------ | ||
1279 | |||
1280 | The `rustc_attrs` feature allows debugging rustc type layouts by using | ||
1281 | `#[rustc_layout(...)]` to debug layout at compile time (it even works | ||
1282 | with `cargo check`) as an alternative to `rustc -Z print-type-sizes` | ||
1283 | that is way more verbose. | ||
1284 | |||
1285 | Options provided by `#[rustc_layout(...)]` are `debug`, `size`, `align`, | ||
1286 | `abi`. Note that it only works on sized types without generics. | ||
1287 | |||
1288 | ## Examples | ||
1289 | |||
1290 | ```rust,compile_fail | ||
1291 | #![feature(rustc_attrs)] | ||
1292 | |||
1293 | #[rustc_layout(abi, size)] | ||
1294 | pub enum X { | ||
1295 | Y(u8, u8, u8), | ||
1296 | Z(isize), | ||
1297 | } | ||
1298 | ``` | ||
1299 | |||
1300 | When that is compiled, the compiler will error with something like | ||
1301 | |||
1302 | ```text | ||
1303 | error: abi: Aggregate { sized: true } | ||
1304 | --> src/lib.rs:4:1 | ||
1305 | | | ||
1306 | 4 | / pub enum T { | ||
1307 | 5 | | Y(u8, u8, u8), | ||
1308 | 6 | | Z(isize), | ||
1309 | 7 | | } | ||
1310 | | |_^ | ||
1311 | |||
1312 | error: size: Size { raw: 16 } | ||
1313 | --> src/lib.rs:4:1 | ||
1314 | | | ||
1315 | 4 | / pub enum T { | ||
1316 | 5 | | Y(u8, u8, u8), | ||
1317 | 6 | | Z(isize), | ||
1318 | 7 | | } | ||
1319 | | |_^ | ||
1320 | |||
1321 | error: aborting due to 2 previous errors | ||
1322 | ``` | ||
1323 | "##, | ||
1324 | }, | ||
1325 | LintCompletion { | ||
1326 | label: "const_fn", | ||
1327 | description: r##"# `const_fn` | ||
1328 | |||
1329 | The tracking issue for this feature is: [#57563] | ||
1330 | |||
1331 | [#57563]: https://github.com/rust-lang/rust/issues/57563 | ||
1332 | |||
1333 | ------------------------ | ||
1334 | |||
1335 | The `const_fn` feature enables additional functionality not stabilized in the | ||
1336 | [minimal subset of `const_fn`](https://github.com/rust-lang/rust/issues/53555) | ||
1337 | "##, | ||
1338 | }, | ||
1339 | LintCompletion { | ||
1340 | label: "abi_thiscall", | ||
1341 | description: r##"# `abi_thiscall` | ||
1342 | |||
1343 | The tracking issue for this feature is: [#42202] | ||
1344 | |||
1345 | [#42202]: https://github.com/rust-lang/rust/issues/42202 | ||
1346 | |||
1347 | ------------------------ | ||
1348 | |||
1349 | The MSVC ABI on x86 Windows uses the `thiscall` calling convention for C++ | ||
1350 | instance methods by default; it is identical to the usual (C) calling | ||
1351 | convention on x86 Windows except that the first parameter of the method, | ||
1352 | the `this` pointer, is passed in the ECX register. | ||
1353 | "##, | ||
1354 | }, | ||
1355 | LintCompletion { | ||
1356 | label: "trait_alias", | ||
1357 | description: r##"# `trait_alias` | ||
1358 | |||
1359 | The tracking issue for this feature is: [#41517] | ||
1360 | |||
1361 | [#41517]: https://github.com/rust-lang/rust/issues/41517 | ||
1362 | |||
1363 | ------------------------ | ||
1364 | |||
1365 | The `trait_alias` feature adds support for trait aliases. These allow aliases | ||
1366 | to be created for one or more traits (currently just a single regular trait plus | ||
1367 | any number of auto-traits), and used wherever traits would normally be used as | ||
1368 | either bounds or trait objects. | ||
1369 | |||
1370 | ```rust | ||
1371 | #![feature(trait_alias)] | ||
1372 | |||
1373 | trait Foo = std::fmt::Debug + Send; | ||
1374 | trait Bar = Foo + Sync; | ||
1375 | |||
1376 | // Use trait alias as bound on type parameter. | ||
1377 | fn foo<T: Foo>(v: &T) { | ||
1378 | println!("{:?}", v); | ||
1379 | } | ||
1380 | |||
1381 | pub fn main() { | ||
1382 | foo(&1); | ||
1383 | |||
1384 | // Use trait alias for trait objects. | ||
1385 | let a: &Bar = &123; | ||
1386 | println!("{:?}", a); | ||
1387 | let b = Box::new(456) as Box<dyn Foo>; | ||
1388 | println!("{:?}", b); | ||
1389 | } | ||
1390 | ``` | ||
1391 | "##, | ||
1392 | }, | ||
1393 | LintCompletion { | ||
1394 | label: "lang_items", | ||
1395 | description: r##"# `lang_items` | ||
1396 | |||
1397 | The tracking issue for this feature is: None. | ||
1398 | |||
1399 | ------------------------ | ||
1400 | |||
1401 | The `rustc` compiler has certain pluggable operations, that is, | ||
1402 | functionality that isn't hard-coded into the language, but is | ||
1403 | implemented in libraries, with a special marker to tell the compiler | ||
1404 | it exists. The marker is the attribute `#[lang = "..."]` and there are | ||
1405 | various different values of `...`, i.e. various different 'lang | ||
1406 | items'. | ||
1407 | |||
1408 | For example, `Box` pointers require two lang items, one for allocation | ||
1409 | and one for deallocation. A freestanding program that uses the `Box` | ||
1410 | sugar for dynamic allocations via `malloc` and `free`: | ||
1411 | |||
1412 | ```rust,ignore (libc-is-finicky) | ||
1413 | #![feature(lang_items, box_syntax, start, libc, core_intrinsics, rustc_private)] | ||
1414 | #![no_std] | ||
1415 | use core::intrinsics; | ||
1416 | use core::panic::PanicInfo; | ||
1417 | |||
1418 | extern crate libc; | ||
1419 | |||
1420 | #[lang = "owned_box"] | ||
1421 | pub struct Box<T>(*mut T); | ||
1422 | |||
1423 | #[lang = "exchange_malloc"] | ||
1424 | unsafe fn allocate(size: usize, _align: usize) -> *mut u8 { | ||
1425 | let p = libc::malloc(size as libc::size_t) as *mut u8; | ||
1426 | |||
1427 | // Check if `malloc` failed: | ||
1428 | if p as usize == 0 { | ||
1429 | intrinsics::abort(); | ||
1430 | } | ||
1431 | |||
1432 | p | ||
1433 | } | ||
1434 | |||
1435 | #[lang = "box_free"] | ||
1436 | unsafe fn box_free<T: ?Sized>(ptr: *mut T) { | ||
1437 | libc::free(ptr as *mut libc::c_void) | ||
1438 | } | ||
1439 | |||
1440 | #[start] | ||
1441 | fn main(_argc: isize, _argv: *const *const u8) -> isize { | ||
1442 | let _x = box 1; | ||
1443 | |||
1444 | 0 | ||
1445 | } | ||
1446 | |||
1447 | #[lang = "eh_personality"] extern fn rust_eh_personality() {} | ||
1448 | #[lang = "panic_impl"] extern fn rust_begin_panic(info: &PanicInfo) -> ! { unsafe { intrinsics::abort() } } | ||
1449 | #[no_mangle] pub extern fn rust_eh_register_frames () {} | ||
1450 | #[no_mangle] pub extern fn rust_eh_unregister_frames () {} | ||
1451 | ``` | ||
1452 | |||
1453 | Note the use of `abort`: the `exchange_malloc` lang item is assumed to | ||
1454 | return a valid pointer, and so needs to do the check internally. | ||
1455 | |||
1456 | Other features provided by lang items include: | ||
1457 | |||
1458 | - overloadable operators via traits: the traits corresponding to the | ||
1459 | `==`, `<`, dereferencing (`*`) and `+` (etc.) operators are all | ||
1460 | marked with lang items; those specific four are `eq`, `ord`, | ||
1461 | `deref`, and `add` respectively. | ||
1462 | - stack unwinding and general failure; the `eh_personality`, | ||
1463 | `panic` and `panic_bounds_check` lang items. | ||
1464 | - the traits in `std::marker` used to indicate types of | ||
1465 | various kinds; lang items `send`, `sync` and `copy`. | ||
1466 | - the marker types and variance indicators found in | ||
1467 | `std::marker`; lang items `covariant_type`, | ||
1468 | `contravariant_lifetime`, etc. | ||
1469 | |||
1470 | Lang items are loaded lazily by the compiler; e.g. if one never uses | ||
1471 | `Box` then there is no need to define functions for `exchange_malloc` | ||
1472 | and `box_free`. `rustc` will emit an error when an item is needed | ||
1473 | but not found in the current crate or any that it depends on. | ||
1474 | |||
1475 | Most lang items are defined by `libcore`, but if you're trying to build | ||
1476 | an executable without the standard library, you'll run into the need | ||
1477 | for lang items. The rest of this page focuses on this use-case, even though | ||
1478 | lang items are a bit broader than that. | ||
1479 | |||
1480 | ### Using libc | ||
1481 | |||
1482 | In order to build a `#[no_std]` executable we will need libc as a dependency. | ||
1483 | We can specify this using our `Cargo.toml` file: | ||
1484 | |||
1485 | ```toml | ||
1486 | [dependencies] | ||
1487 | libc = { version = "0.2.14", default-features = false } | ||
1488 | ``` | ||
1489 | |||
1490 | Note that the default features have been disabled. This is a critical step - | ||
1491 | **the default features of libc include the standard library and so must be | ||
1492 | disabled.** | ||
1493 | |||
1494 | ### Writing an executable without stdlib | ||
1495 | |||
1496 | Controlling the entry point is possible in two ways: the `#[start]` attribute, | ||
1497 | or overriding the default shim for the C `main` function with your own. | ||
1498 | |||
1499 | The function marked `#[start]` is passed the command line parameters | ||
1500 | in the same format as C: | ||
1501 | |||
1502 | ```rust,ignore (libc-is-finicky) | ||
1503 | #![feature(lang_items, core_intrinsics, rustc_private)] | ||
1504 | #![feature(start)] | ||
1505 | #![no_std] | ||
1506 | use core::intrinsics; | ||
1507 | use core::panic::PanicInfo; | ||
1508 | |||
1509 | // Pull in the system libc library for what crt0.o likely requires. | ||
1510 | extern crate libc; | ||
1511 | |||
1512 | // Entry point for this program. | ||
1513 | #[start] | ||
1514 | fn start(_argc: isize, _argv: *const *const u8) -> isize { | ||
1515 | 0 | ||
1516 | } | ||
1517 | |||
1518 | // These functions are used by the compiler, but not | ||
1519 | // for a bare-bones hello world. These are normally | ||
1520 | // provided by libstd. | ||
1521 | #[lang = "eh_personality"] | ||
1522 | #[no_mangle] | ||
1523 | pub extern fn rust_eh_personality() { | ||
1524 | } | ||
1525 | |||
1526 | #[lang = "panic_impl"] | ||
1527 | #[no_mangle] | ||
1528 | pub extern fn rust_begin_panic(info: &PanicInfo) -> ! { | ||
1529 | unsafe { intrinsics::abort() } | ||
1530 | } | ||
1531 | ``` | ||
1532 | |||
1533 | To override the compiler-inserted `main` shim, one has to disable it | ||
1534 | with `#![no_main]` and then create the appropriate symbol with the | ||
1535 | correct ABI and the correct name, which requires overriding the | ||
1536 | compiler's name mangling too: | ||
1537 | |||
1538 | ```rust,ignore (libc-is-finicky) | ||
1539 | #![feature(lang_items, core_intrinsics, rustc_private)] | ||
1540 | #![feature(start)] | ||
1541 | #![no_std] | ||
1542 | #![no_main] | ||
1543 | use core::intrinsics; | ||
1544 | use core::panic::PanicInfo; | ||
1545 | |||
1546 | // Pull in the system libc library for what crt0.o likely requires. | ||
1547 | extern crate libc; | ||
1548 | |||
1549 | // Entry point for this program. | ||
1550 | #[no_mangle] // ensure that this symbol is called `main` in the output | ||
1551 | pub extern fn main(_argc: i32, _argv: *const *const u8) -> i32 { | ||
1552 | 0 | ||
1553 | } | ||
1554 | |||
1555 | // These functions are used by the compiler, but not | ||
1556 | // for a bare-bones hello world. These are normally | ||
1557 | // provided by libstd. | ||
1558 | #[lang = "eh_personality"] | ||
1559 | #[no_mangle] | ||
1560 | pub extern fn rust_eh_personality() { | ||
1561 | } | ||
1562 | |||
1563 | #[lang = "panic_impl"] | ||
1564 | #[no_mangle] | ||
1565 | pub extern fn rust_begin_panic(info: &PanicInfo) -> ! { | ||
1566 | unsafe { intrinsics::abort() } | ||
1567 | } | ||
1568 | ``` | ||
1569 | |||
1570 | In many cases, you may need to manually link to the `compiler_builtins` crate | ||
1571 | when building a `no_std` binary. You may observe this via linker error messages | ||
1572 | such as "```undefined reference to `__rust_probestack'```". | ||
1573 | |||
1574 | ## More about the language items | ||
1575 | |||
1576 | The compiler currently makes a few assumptions about symbols which are | ||
1577 | available in the executable to call. Normally these functions are provided by | ||
1578 | the standard library, but without it you must define your own. These symbols | ||
1579 | are called "language items", and they each have an internal name, and then a | ||
1580 | signature that an implementation must conform to. | ||
1581 | |||
1582 | The first of these functions, `rust_eh_personality`, is used by the failure | ||
1583 | mechanisms of the compiler. This is often mapped to GCC's personality function | ||
1584 | (see the [libstd implementation][unwind] for more information), but crates | ||
1585 | which do not trigger a panic can be assured that this function is never | ||
1586 | called. The language item's name is `eh_personality`. | ||
1587 | |||
1588 | [unwind]: https://github.com/rust-lang/rust/blob/master/src/libpanic_unwind/gcc.rs | ||
1589 | |||
1590 | The second function, `rust_begin_panic`, is also used by the failure mechanisms of the | ||
1591 | compiler. When a panic happens, this controls the message that's displayed on | ||
1592 | the screen. While the language item's name is `panic_impl`, the symbol name is | ||
1593 | `rust_begin_panic`. | ||
1594 | |||
1595 | Finally, a `eh_catch_typeinfo` static is needed for certain targets which | ||
1596 | implement Rust panics on top of C++ exceptions. | ||
1597 | |||
1598 | ## List of all language items | ||
1599 | |||
1600 | This is a list of all language items in Rust along with where they are located in | ||
1601 | the source code. | ||
1602 | |||
1603 | - Primitives | ||
1604 | - `i8`: `libcore/num/mod.rs` | ||
1605 | - `i16`: `libcore/num/mod.rs` | ||
1606 | - `i32`: `libcore/num/mod.rs` | ||
1607 | - `i64`: `libcore/num/mod.rs` | ||
1608 | - `i128`: `libcore/num/mod.rs` | ||
1609 | - `isize`: `libcore/num/mod.rs` | ||
1610 | - `u8`: `libcore/num/mod.rs` | ||
1611 | - `u16`: `libcore/num/mod.rs` | ||
1612 | - `u32`: `libcore/num/mod.rs` | ||
1613 | - `u64`: `libcore/num/mod.rs` | ||
1614 | - `u128`: `libcore/num/mod.rs` | ||
1615 | - `usize`: `libcore/num/mod.rs` | ||
1616 | - `f32`: `libstd/f32.rs` | ||
1617 | - `f64`: `libstd/f64.rs` | ||
1618 | - `char`: `libcore/char.rs` | ||
1619 | - `slice`: `liballoc/slice.rs` | ||
1620 | - `str`: `liballoc/str.rs` | ||
1621 | - `const_ptr`: `libcore/ptr.rs` | ||
1622 | - `mut_ptr`: `libcore/ptr.rs` | ||
1623 | - `unsafe_cell`: `libcore/cell.rs` | ||
1624 | - Runtime | ||
1625 | - `start`: `libstd/rt.rs` | ||
1626 | - `eh_personality`: `libpanic_unwind/emcc.rs` (EMCC) | ||
1627 | - `eh_personality`: `libpanic_unwind/gcc.rs` (GNU) | ||
1628 | - `eh_personality`: `libpanic_unwind/seh.rs` (SEH) | ||
1629 | - `eh_catch_typeinfo`: `libpanic_unwind/emcc.rs` (EMCC) | ||
1630 | - `panic`: `libcore/panicking.rs` | ||
1631 | - `panic_bounds_check`: `libcore/panicking.rs` | ||
1632 | - `panic_impl`: `libcore/panicking.rs` | ||
1633 | - `panic_impl`: `libstd/panicking.rs` | ||
1634 | - Allocations | ||
1635 | - `owned_box`: `liballoc/boxed.rs` | ||
1636 | - `exchange_malloc`: `liballoc/heap.rs` | ||
1637 | - `box_free`: `liballoc/heap.rs` | ||
1638 | - Operands | ||
1639 | - `not`: `libcore/ops/bit.rs` | ||
1640 | - `bitand`: `libcore/ops/bit.rs` | ||
1641 | - `bitor`: `libcore/ops/bit.rs` | ||
1642 | - `bitxor`: `libcore/ops/bit.rs` | ||
1643 | - `shl`: `libcore/ops/bit.rs` | ||
1644 | - `shr`: `libcore/ops/bit.rs` | ||
1645 | - `bitand_assign`: `libcore/ops/bit.rs` | ||
1646 | - `bitor_assign`: `libcore/ops/bit.rs` | ||
1647 | - `bitxor_assign`: `libcore/ops/bit.rs` | ||
1648 | - `shl_assign`: `libcore/ops/bit.rs` | ||
1649 | - `shr_assign`: `libcore/ops/bit.rs` | ||
1650 | - `deref`: `libcore/ops/deref.rs` | ||
1651 | - `deref_mut`: `libcore/ops/deref.rs` | ||
1652 | - `index`: `libcore/ops/index.rs` | ||
1653 | - `index_mut`: `libcore/ops/index.rs` | ||
1654 | - `add`: `libcore/ops/arith.rs` | ||
1655 | - `sub`: `libcore/ops/arith.rs` | ||
1656 | - `mul`: `libcore/ops/arith.rs` | ||
1657 | - `div`: `libcore/ops/arith.rs` | ||
1658 | - `rem`: `libcore/ops/arith.rs` | ||
1659 | - `neg`: `libcore/ops/arith.rs` | ||
1660 | - `add_assign`: `libcore/ops/arith.rs` | ||
1661 | - `sub_assign`: `libcore/ops/arith.rs` | ||
1662 | - `mul_assign`: `libcore/ops/arith.rs` | ||
1663 | - `div_assign`: `libcore/ops/arith.rs` | ||
1664 | - `rem_assign`: `libcore/ops/arith.rs` | ||
1665 | - `eq`: `libcore/cmp.rs` | ||
1666 | - `ord`: `libcore/cmp.rs` | ||
1667 | - Functions | ||
1668 | - `fn`: `libcore/ops/function.rs` | ||
1669 | - `fn_mut`: `libcore/ops/function.rs` | ||
1670 | - `fn_once`: `libcore/ops/function.rs` | ||
1671 | - `generator_state`: `libcore/ops/generator.rs` | ||
1672 | - `generator`: `libcore/ops/generator.rs` | ||
1673 | - Other | ||
1674 | - `coerce_unsized`: `libcore/ops/unsize.rs` | ||
1675 | - `drop`: `libcore/ops/drop.rs` | ||
1676 | - `drop_in_place`: `libcore/ptr.rs` | ||
1677 | - `clone`: `libcore/clone.rs` | ||
1678 | - `copy`: `libcore/marker.rs` | ||
1679 | - `send`: `libcore/marker.rs` | ||
1680 | - `sized`: `libcore/marker.rs` | ||
1681 | - `unsize`: `libcore/marker.rs` | ||
1682 | - `sync`: `libcore/marker.rs` | ||
1683 | - `phantom_data`: `libcore/marker.rs` | ||
1684 | - `discriminant_kind`: `libcore/marker.rs` | ||
1685 | - `freeze`: `libcore/marker.rs` | ||
1686 | - `debug_trait`: `libcore/fmt/mod.rs` | ||
1687 | - `non_zero`: `libcore/nonzero.rs` | ||
1688 | - `arc`: `liballoc/sync.rs` | ||
1689 | - `rc`: `liballoc/rc.rs` | ||
1690 | "##, | ||
1691 | }, | ||
1692 | LintCompletion { | ||
1693 | label: "doc_spotlight", | ||
1694 | description: r##"# `doc_spotlight` | ||
1695 | |||
1696 | The tracking issue for this feature is: [#45040] | ||
1697 | |||
1698 | The `doc_spotlight` feature allows the use of the `spotlight` parameter to the `#[doc]` attribute, | ||
1699 | to "spotlight" a specific trait on the return values of functions. Adding a `#[doc(spotlight)]` | ||
1700 | attribute to a trait definition will make rustdoc print extra information for functions which return | ||
1701 | a type that implements that trait. For example, this attribute is applied to the `Iterator`, | ||
1702 | `io::Read`, `io::Write`, and `Future` traits in the standard library. | ||
1703 | |||
1704 | You can do this on your own traits, like this: | ||
1705 | |||
1706 | ``` | ||
1707 | #![feature(doc_spotlight)] | ||
1708 | |||
1709 | #[doc(spotlight)] | ||
1710 | pub trait MyTrait {} | ||
1711 | |||
1712 | pub struct MyStruct; | ||
1713 | impl MyTrait for MyStruct {} | ||
1714 | |||
1715 | /// The docs for this function will have an extra line about `MyStruct` implementing `MyTrait`, | ||
1716 | /// without having to write that yourself! | ||
1717 | pub fn my_fn() -> MyStruct { MyStruct } | ||
1718 | ``` | ||
1719 | |||
1720 | This feature was originally implemented in PR [#45039]. | ||
1721 | |||
1722 | [#45040]: https://github.com/rust-lang/rust/issues/45040 | ||
1723 | [#45039]: https://github.com/rust-lang/rust/pull/45039 | ||
1724 | "##, | ||
1725 | }, | ||
1726 | LintCompletion { | ||
1727 | label: "c_variadic", | ||
1728 | description: r##"# `c_variadic` | ||
1729 | |||
1730 | The tracking issue for this feature is: [#44930] | ||
1731 | |||
1732 | [#44930]: https://github.com/rust-lang/rust/issues/44930 | ||
1733 | |||
1734 | ------------------------ | ||
1735 | |||
1736 | The `c_variadic` language feature enables C-variadic functions to be | ||
1737 | defined in Rust. The may be called both from within Rust and via FFI. | ||
1738 | |||
1739 | ## Examples | ||
1740 | |||
1741 | ```rust | ||
1742 | #![feature(c_variadic)] | ||
1743 | |||
1744 | pub unsafe extern "C" fn add(n: usize, mut args: ...) -> usize { | ||
1745 | let mut sum = 0; | ||
1746 | for _ in 0..n { | ||
1747 | sum += args.arg::<usize>(); | ||
1748 | } | ||
1749 | sum | ||
1750 | } | ||
1751 | ``` | ||
1752 | "##, | ||
1753 | }, | ||
1754 | LintCompletion { | ||
1755 | label: "intra_doc_pointers", | ||
1756 | description: r##"# `intra-doc-pointers` | ||
1757 | |||
1758 | The tracking issue for this feature is: [#80896] | ||
1759 | |||
1760 | [#80896]: https://github.com/rust-lang/rust/issues/80896 | ||
1761 | |||
1762 | ------------------------ | ||
1763 | |||
1764 | Rustdoc does not currently allow disambiguating between `*const` and `*mut`, and | ||
1765 | raw pointers in intra-doc links are unstable until it does. | ||
1766 | |||
1767 | ```rust | ||
1768 | #![feature(intra_doc_pointers)] | ||
1769 | //! [pointer::add] | ||
1770 | ``` | ||
1771 | "##, | ||
1772 | }, | ||
1773 | LintCompletion { | ||
1774 | label: "box_syntax", | ||
1775 | description: r##"# `box_syntax` | ||
1776 | |||
1777 | The tracking issue for this feature is: [#49733] | ||
1778 | |||
1779 | [#49733]: https://github.com/rust-lang/rust/issues/49733 | ||
1780 | |||
1781 | See also [`box_patterns`](box-patterns.md) | ||
1782 | |||
1783 | ------------------------ | ||
1784 | |||
1785 | Currently the only stable way to create a `Box` is via the `Box::new` method. | ||
1786 | Also it is not possible in stable Rust to destructure a `Box` in a match | ||
1787 | pattern. The unstable `box` keyword can be used to create a `Box`. An example | ||
1788 | usage would be: | ||
1789 | |||
1790 | ```rust | ||
1791 | #![feature(box_syntax)] | ||
1792 | |||
1793 | fn main() { | ||
1794 | let b = box 5; | ||
1795 | } | ||
1796 | ``` | ||
1797 | "##, | ||
1798 | }, | ||
1799 | LintCompletion { | ||
1800 | label: "unsized_locals", | ||
1801 | description: r##"# `unsized_locals` | ||
1802 | |||
1803 | The tracking issue for this feature is: [#48055] | ||
1804 | |||
1805 | [#48055]: https://github.com/rust-lang/rust/issues/48055 | ||
1806 | |||
1807 | ------------------------ | ||
1808 | |||
1809 | This implements [RFC1909]. When turned on, you can have unsized arguments and locals: | ||
1810 | |||
1811 | [RFC1909]: https://github.com/rust-lang/rfcs/blob/master/text/1909-unsized-rvalues.md | ||
1812 | |||
1813 | ```rust | ||
1814 | #![allow(incomplete_features)] | ||
1815 | #![feature(unsized_locals, unsized_fn_params)] | ||
1816 | |||
1817 | use std::any::Any; | ||
1818 | |||
1819 | fn main() { | ||
1820 | let x: Box<dyn Any> = Box::new(42); | ||
1821 | let x: dyn Any = *x; | ||
1822 | // ^ unsized local variable | ||
1823 | // ^^ unsized temporary | ||
1824 | foo(x); | ||
1825 | } | ||
1826 | |||
1827 | fn foo(_: dyn Any) {} | ||
1828 | // ^^^^^^ unsized argument | ||
1829 | ``` | ||
1830 | |||
1831 | The RFC still forbids the following unsized expressions: | ||
1832 | |||
1833 | ```rust,compile_fail | ||
1834 | #![feature(unsized_locals)] | ||
1835 | |||
1836 | use std::any::Any; | ||
1837 | |||
1838 | struct MyStruct<T: ?Sized> { | ||
1839 | content: T, | ||
1840 | } | ||
1841 | |||
1842 | struct MyTupleStruct<T: ?Sized>(T); | ||
1843 | |||
1844 | fn answer() -> Box<dyn Any> { | ||
1845 | Box::new(42) | ||
1846 | } | ||
1847 | |||
1848 | fn main() { | ||
1849 | // You CANNOT have unsized statics. | ||
1850 | static X: dyn Any = *answer(); // ERROR | ||
1851 | const Y: dyn Any = *answer(); // ERROR | ||
1852 | |||
1853 | // You CANNOT have struct initialized unsized. | ||
1854 | MyStruct { content: *answer() }; // ERROR | ||
1855 | MyTupleStruct(*answer()); // ERROR | ||
1856 | (42, *answer()); // ERROR | ||
1857 | |||
1858 | // You CANNOT have unsized return types. | ||
1859 | fn my_function() -> dyn Any { *answer() } // ERROR | ||
1860 | |||
1861 | // You CAN have unsized local variables... | ||
1862 | let mut x: dyn Any = *answer(); // OK | ||
1863 | // ...but you CANNOT reassign to them. | ||
1864 | x = *answer(); // ERROR | ||
1865 | |||
1866 | // You CANNOT even initialize them separately. | ||
1867 | let y: dyn Any; // OK | ||
1868 | y = *answer(); // ERROR | ||
1869 | |||
1870 | // Not mentioned in the RFC, but by-move captured variables are also Sized. | ||
1871 | let x: dyn Any = *answer(); | ||
1872 | (move || { // ERROR | ||
1873 | let y = x; | ||
1874 | })(); | ||
1875 | |||
1876 | // You CAN create a closure with unsized arguments, | ||
1877 | // but you CANNOT call it. | ||
1878 | // This is an implementation detail and may be changed in the future. | ||
1879 | let f = |x: dyn Any| {}; | ||
1880 | f(*answer()); // ERROR | ||
1881 | } | ||
1882 | ``` | ||
1883 | |||
1884 | ## By-value trait objects | ||
1885 | |||
1886 | With this feature, you can have by-value `self` arguments without `Self: Sized` bounds. | ||
1887 | |||
1888 | ```rust | ||
1889 | #![feature(unsized_fn_params)] | ||
1890 | |||
1891 | trait Foo { | ||
1892 | fn foo(self) {} | ||
1893 | } | ||
1894 | |||
1895 | impl<T: ?Sized> Foo for T {} | ||
1896 | |||
1897 | fn main() { | ||
1898 | let slice: Box<[i32]> = Box::new([1, 2, 3]); | ||
1899 | <[i32] as Foo>::foo(*slice); | ||
1900 | } | ||
1901 | ``` | ||
1902 | |||
1903 | And `Foo` will also be object-safe. | ||
1904 | |||
1905 | ```rust | ||
1906 | #![feature(unsized_fn_params)] | ||
1907 | |||
1908 | trait Foo { | ||
1909 | fn foo(self) {} | ||
1910 | } | ||
1911 | |||
1912 | impl<T: ?Sized> Foo for T {} | ||
1913 | |||
1914 | fn main () { | ||
1915 | let slice: Box<dyn Foo> = Box::new([1, 2, 3]); | ||
1916 | // doesn't compile yet | ||
1917 | <dyn Foo as Foo>::foo(*slice); | ||
1918 | } | ||
1919 | ``` | ||
1920 | |||
1921 | One of the objectives of this feature is to allow `Box<dyn FnOnce>`. | ||
1922 | |||
1923 | ## Variable length arrays | ||
1924 | |||
1925 | The RFC also describes an extension to the array literal syntax: `[e; dyn n]`. In the syntax, `n` isn't necessarily a constant expression. The array is dynamically allocated on the stack and has the type of `[T]`, instead of `[T; n]`. | ||
1926 | |||
1927 | ```rust,ignore (not-yet-implemented) | ||
1928 | #![feature(unsized_locals)] | ||
1929 | |||
1930 | fn mergesort<T: Ord>(a: &mut [T]) { | ||
1931 | let mut tmp = [T; dyn a.len()]; | ||
1932 | // ... | ||
1933 | } | ||
1934 | |||
1935 | fn main() { | ||
1936 | let mut a = [3, 1, 5, 6]; | ||
1937 | mergesort(&mut a); | ||
1938 | assert_eq!(a, [1, 3, 5, 6]); | ||
1939 | } | ||
1940 | ``` | ||
1941 | |||
1942 | VLAs are not implemented yet. The syntax isn't final, either. We may need an alternative syntax for Rust 2015 because, in Rust 2015, expressions like `[e; dyn(1)]` would be ambiguous. One possible alternative proposed in the RFC is `[e; n]`: if `n` captures one or more local variables, then it is considered as `[e; dyn n]`. | ||
1943 | |||
1944 | ## Advisory on stack usage | ||
1945 | |||
1946 | It's advised not to casually use the `#![feature(unsized_locals)]` feature. Typical use-cases are: | ||
1947 | |||
1948 | - When you need a by-value trait objects. | ||
1949 | - When you really need a fast allocation of small temporary arrays. | ||
1950 | |||
1951 | Another pitfall is repetitive allocation and temporaries. Currently the compiler simply extends the stack frame every time it encounters an unsized assignment. So for example, the code | ||
1952 | |||
1953 | ```rust | ||
1954 | #![feature(unsized_locals)] | ||
1955 | |||
1956 | fn main() { | ||
1957 | let x: Box<[i32]> = Box::new([1, 2, 3, 4, 5]); | ||
1958 | let _x = {{{{{{{{{{*x}}}}}}}}}}; | ||
1959 | } | ||
1960 | ``` | ||
1961 | |||
1962 | and the code | ||
1963 | |||
1964 | ```rust | ||
1965 | #![feature(unsized_locals)] | ||
1966 | |||
1967 | fn main() { | ||
1968 | for _ in 0..10 { | ||
1969 | let x: Box<[i32]> = Box::new([1, 2, 3, 4, 5]); | ||
1970 | let _x = *x; | ||
1971 | } | ||
1972 | } | ||
1973 | ``` | ||
1974 | |||
1975 | will unnecessarily extend the stack frame. | ||
1976 | "##, | ||
1977 | }, | ||
1978 | LintCompletion { | ||
1979 | label: "arbitrary_enum_discriminant", | ||
1980 | description: r##"# `arbitrary_enum_discriminant` | ||
1981 | |||
1982 | The tracking issue for this feature is: [#60553] | ||
1983 | |||
1984 | [#60553]: https://github.com/rust-lang/rust/issues/60553 | ||
1985 | |||
1986 | ------------------------ | ||
1987 | |||
1988 | The `arbitrary_enum_discriminant` feature permits tuple-like and | ||
1989 | struct-like enum variants with `#[repr(<int-type>)]` to have explicit discriminants. | ||
1990 | |||
1991 | ## Examples | ||
1992 | |||
1993 | ```rust | ||
1994 | #![feature(arbitrary_enum_discriminant)] | ||
1995 | |||
1996 | #[allow(dead_code)] | ||
1997 | #[repr(u8)] | ||
1998 | enum Enum { | ||
1999 | Unit = 3, | ||
2000 | Tuple(u16) = 2, | ||
2001 | Struct { | ||
2002 | a: u8, | ||
2003 | b: u16, | ||
2004 | } = 1, | ||
2005 | } | ||
2006 | |||
2007 | impl Enum { | ||
2008 | fn tag(&self) -> u8 { | ||
2009 | unsafe { *(self as *const Self as *const u8) } | ||
2010 | } | ||
2011 | } | ||
2012 | |||
2013 | assert_eq!(3, Enum::Unit.tag()); | ||
2014 | assert_eq!(2, Enum::Tuple(5).tag()); | ||
2015 | assert_eq!(1, Enum::Struct{a: 7, b: 11}.tag()); | ||
2016 | ``` | ||
2017 | "##, | ||
2018 | }, | ||
2019 | LintCompletion { | ||
2020 | label: "unboxed_closures", | ||
2021 | description: r##"# `unboxed_closures` | ||
2022 | |||
2023 | The tracking issue for this feature is [#29625] | ||
2024 | |||
2025 | See Also: [`fn_traits`](../library-features/fn-traits.md) | ||
2026 | |||
2027 | [#29625]: https://github.com/rust-lang/rust/issues/29625 | ||
2028 | |||
2029 | ---- | ||
2030 | |||
2031 | The `unboxed_closures` feature allows you to write functions using the `"rust-call"` ABI, | ||
2032 | required for implementing the [`Fn*`] family of traits. `"rust-call"` functions must have | ||
2033 | exactly one (non self) argument, a tuple representing the argument list. | ||
2034 | |||
2035 | [`Fn*`]: https://doc.rust-lang.org/std/ops/trait.Fn.html | ||
2036 | |||
2037 | ```rust | ||
2038 | #![feature(unboxed_closures)] | ||
2039 | |||
2040 | extern "rust-call" fn add_args(args: (u32, u32)) -> u32 { | ||
2041 | args.0 + args.1 | ||
2042 | } | ||
2043 | |||
2044 | fn main() {} | ||
2045 | ``` | ||
2046 | "##, | ||
2047 | }, | ||
2048 | LintCompletion { | ||
2049 | label: "custom_test_frameworks", | ||
2050 | description: r##"# `custom_test_frameworks` | ||
2051 | |||
2052 | The tracking issue for this feature is: [#50297] | ||
2053 | |||
2054 | [#50297]: https://github.com/rust-lang/rust/issues/50297 | ||
2055 | |||
2056 | ------------------------ | ||
2057 | |||
2058 | The `custom_test_frameworks` feature allows the use of `#[test_case]` and `#![test_runner]`. | ||
2059 | Any function, const, or static can be annotated with `#[test_case]` causing it to be aggregated (like `#[test]`) | ||
2060 | and be passed to the test runner determined by the `#![test_runner]` crate attribute. | ||
2061 | |||
2062 | ```rust | ||
2063 | #![feature(custom_test_frameworks)] | ||
2064 | #![test_runner(my_runner)] | ||
2065 | |||
2066 | fn my_runner(tests: &[&i32]) { | ||
2067 | for t in tests { | ||
2068 | if **t == 0 { | ||
2069 | println!("PASSED"); | ||
2070 | } else { | ||
2071 | println!("FAILED"); | ||
2072 | } | ||
2073 | } | ||
2074 | } | ||
2075 | |||
2076 | #[test_case] | ||
2077 | const WILL_PASS: i32 = 0; | ||
2078 | |||
2079 | #[test_case] | ||
2080 | const WILL_FAIL: i32 = 4; | ||
2081 | ``` | ||
2082 | "##, | ||
2083 | }, | ||
2084 | LintCompletion { | ||
2085 | label: "abi_msp430_interrupt", | 577 | label: "abi_msp430_interrupt", |
2086 | description: r##"# `abi_msp430_interrupt` | 578 | description: r##"# `abi_msp430_interrupt` |
2087 | 579 | ||
@@ -2127,201 +619,7 @@ Disassembly of section .text: | |||
2127 | ``` | 619 | ``` |
2128 | "##, | 620 | "##, |
2129 | }, | 621 | }, |
2130 | LintCompletion { | 622 | Lint { |
2131 | label: "impl_trait_in_bindings", | ||
2132 | description: r##"# `impl_trait_in_bindings` | ||
2133 | |||
2134 | The tracking issue for this feature is: [#63065] | ||
2135 | |||
2136 | [#63065]: https://github.com/rust-lang/rust/issues/63065 | ||
2137 | |||
2138 | ------------------------ | ||
2139 | |||
2140 | The `impl_trait_in_bindings` feature gate lets you use `impl Trait` syntax in | ||
2141 | `let`, `static`, and `const` bindings. | ||
2142 | |||
2143 | A simple example is: | ||
2144 | |||
2145 | ```rust | ||
2146 | #![feature(impl_trait_in_bindings)] | ||
2147 | |||
2148 | use std::fmt::Debug; | ||
2149 | |||
2150 | fn main() { | ||
2151 | let a: impl Debug + Clone = 42; | ||
2152 | let b = a.clone(); | ||
2153 | println!("{:?}", b); // prints `42` | ||
2154 | } | ||
2155 | ``` | ||
2156 | |||
2157 | Note however that because the types of `a` and `b` are opaque in the above | ||
2158 | example, calling inherent methods or methods outside of the specified traits | ||
2159 | (e.g., `a.abs()` or `b.abs()`) is not allowed, and yields an error. | ||
2160 | "##, | ||
2161 | }, | ||
2162 | LintCompletion { | ||
2163 | label: "cfg_version", | ||
2164 | description: r##"# `cfg_version` | ||
2165 | |||
2166 | The tracking issue for this feature is: [#64796] | ||
2167 | |||
2168 | [#64796]: https://github.com/rust-lang/rust/issues/64796 | ||
2169 | |||
2170 | ------------------------ | ||
2171 | |||
2172 | The `cfg_version` feature makes it possible to execute different code | ||
2173 | depending on the compiler version. | ||
2174 | |||
2175 | ## Examples | ||
2176 | |||
2177 | ```rust | ||
2178 | #![feature(cfg_version)] | ||
2179 | |||
2180 | #[cfg(version("1.42"))] | ||
2181 | fn a() { | ||
2182 | // ... | ||
2183 | } | ||
2184 | |||
2185 | #[cfg(not(version("1.42")))] | ||
2186 | fn a() { | ||
2187 | // ... | ||
2188 | } | ||
2189 | |||
2190 | fn b() { | ||
2191 | if cfg!(version("1.42")) { | ||
2192 | // ... | ||
2193 | } else { | ||
2194 | // ... | ||
2195 | } | ||
2196 | } | ||
2197 | ``` | ||
2198 | "##, | ||
2199 | }, | ||
2200 | LintCompletion { | ||
2201 | label: "link_cfg", | ||
2202 | description: r##"# `link_cfg` | ||
2203 | |||
2204 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2205 | |||
2206 | ------------------------ | ||
2207 | "##, | ||
2208 | }, | ||
2209 | LintCompletion { | ||
2210 | label: "infer_static_outlives_requirements", | ||
2211 | description: r##"# `infer_static_outlives_requirements` | ||
2212 | |||
2213 | The tracking issue for this feature is: [#54185] | ||
2214 | |||
2215 | [#54185]: https://github.com/rust-lang/rust/issues/54185 | ||
2216 | |||
2217 | ------------------------ | ||
2218 | The `infer_static_outlives_requirements` feature indicates that certain | ||
2219 | `'static` outlives requirements can be inferred by the compiler rather than | ||
2220 | stating them explicitly. | ||
2221 | |||
2222 | Note: It is an accompanying feature to `infer_outlives_requirements`, | ||
2223 | which must be enabled to infer outlives requirements. | ||
2224 | |||
2225 | For example, currently generic struct definitions that contain | ||
2226 | references, require where-clauses of the form T: 'static. By using | ||
2227 | this feature the outlives predicates will be inferred, although | ||
2228 | they may still be written explicitly. | ||
2229 | |||
2230 | ```rust,ignore (pseudo-Rust) | ||
2231 | struct Foo<U> where U: 'static { // <-- currently required | ||
2232 | bar: Bar<U> | ||
2233 | } | ||
2234 | struct Bar<T: 'static> { | ||
2235 | x: T, | ||
2236 | } | ||
2237 | ``` | ||
2238 | |||
2239 | |||
2240 | ## Examples: | ||
2241 | |||
2242 | ```rust,ignore (pseudo-Rust) | ||
2243 | #![feature(infer_outlives_requirements)] | ||
2244 | #![feature(infer_static_outlives_requirements)] | ||
2245 | |||
2246 | #[rustc_outlives] | ||
2247 | // Implicitly infer U: 'static | ||
2248 | struct Foo<U> { | ||
2249 | bar: Bar<U> | ||
2250 | } | ||
2251 | struct Bar<T: 'static> { | ||
2252 | x: T, | ||
2253 | } | ||
2254 | ``` | ||
2255 | "##, | ||
2256 | }, | ||
2257 | LintCompletion { | ||
2258 | label: "marker_trait_attr", | ||
2259 | description: r##"# `marker_trait_attr` | ||
2260 | |||
2261 | The tracking issue for this feature is: [#29864] | ||
2262 | |||
2263 | [#29864]: https://github.com/rust-lang/rust/issues/29864 | ||
2264 | |||
2265 | ------------------------ | ||
2266 | |||
2267 | Normally, Rust keeps you from adding trait implementations that could | ||
2268 | overlap with each other, as it would be ambiguous which to use. This | ||
2269 | feature, however, carves out an exception to that rule: a trait can | ||
2270 | opt-in to having overlapping implementations, at the cost that those | ||
2271 | implementations are not allowed to override anything (and thus the | ||
2272 | trait itself cannot have any associated items, as they're pointless | ||
2273 | when they'd need to do the same thing for every type anyway). | ||
2274 | |||
2275 | ```rust | ||
2276 | #![feature(marker_trait_attr)] | ||
2277 | |||
2278 | #[marker] trait CheapToClone: Clone {} | ||
2279 | |||
2280 | impl<T: Copy> CheapToClone for T {} | ||
2281 | |||
2282 | // These could potentially overlap with the blanket implementation above, | ||
2283 | // so are only allowed because CheapToClone is a marker trait. | ||
2284 | impl<T: CheapToClone, U: CheapToClone> CheapToClone for (T, U) {} | ||
2285 | impl<T: CheapToClone> CheapToClone for std::ops::Range<T> {} | ||
2286 | |||
2287 | fn cheap_clone<T: CheapToClone>(t: T) -> T { | ||
2288 | t.clone() | ||
2289 | } | ||
2290 | ``` | ||
2291 | |||
2292 | This is expected to replace the unstable `overlapping_marker_traits` | ||
2293 | feature, which applied to all empty traits (without needing an opt-in). | ||
2294 | "##, | ||
2295 | }, | ||
2296 | LintCompletion { | ||
2297 | label: "doc_masked", | ||
2298 | description: r##"# `doc_masked` | ||
2299 | |||
2300 | The tracking issue for this feature is: [#44027] | ||
2301 | |||
2302 | ----- | ||
2303 | |||
2304 | The `doc_masked` feature allows a crate to exclude types from a given crate from appearing in lists | ||
2305 | of trait implementations. The specifics of the feature are as follows: | ||
2306 | |||
2307 | 1. When rustdoc encounters an `extern crate` statement annotated with a `#[doc(masked)]` attribute, | ||
2308 | it marks the crate as being masked. | ||
2309 | |||
2310 | 2. When listing traits a given type implements, rustdoc ensures that traits from masked crates are | ||
2311 | not emitted into the documentation. | ||
2312 | |||
2313 | 3. When listing types that implement a given trait, rustdoc ensures that types from masked crates | ||
2314 | are not emitted into the documentation. | ||
2315 | |||
2316 | This feature was introduced in PR [#44026] to ensure that compiler-internal and | ||
2317 | implementation-specific types and traits were not included in the standard library's documentation. | ||
2318 | Such types would introduce broken links into the documentation. | ||
2319 | |||
2320 | [#44026]: https://github.com/rust-lang/rust/pull/44026 | ||
2321 | [#44027]: https://github.com/rust-lang/rust/pull/44027 | ||
2322 | "##, | ||
2323 | }, | ||
2324 | LintCompletion { | ||
2325 | label: "abi_ptx", | 623 | label: "abi_ptx", |
2326 | description: r##"# `abi_ptx` | 624 | description: r##"# `abi_ptx` |
2327 | 625 | ||
@@ -2385,340 +683,94 @@ $ cat $(find -name '*.s') | |||
2385 | ``` | 683 | ``` |
2386 | "##, | 684 | "##, |
2387 | }, | 685 | }, |
2388 | LintCompletion { | 686 | Lint { |
2389 | label: "profiler_runtime", | 687 | label: "abi_thiscall", |
2390 | description: r##"# `profiler_runtime` | 688 | description: r##"# `abi_thiscall` |
2391 | |||
2392 | The tracking issue for this feature is: [#42524](https://github.com/rust-lang/rust/issues/42524). | ||
2393 | |||
2394 | ------------------------ | ||
2395 | "##, | ||
2396 | }, | ||
2397 | LintCompletion { | ||
2398 | label: "crate_visibility_modifier", | ||
2399 | description: r##"# `crate_visibility_modifier` | ||
2400 | |||
2401 | The tracking issue for this feature is: [#53120] | ||
2402 | |||
2403 | [#53120]: https://github.com/rust-lang/rust/issues/53120 | ||
2404 | |||
2405 | ----- | ||
2406 | |||
2407 | The `crate_visibility_modifier` feature allows the `crate` keyword to be used | ||
2408 | as a visibility modifier synonymous to `pub(crate)`, indicating that a type | ||
2409 | (function, _&c._) is to be visible to the entire enclosing crate, but not to | ||
2410 | other crates. | ||
2411 | |||
2412 | ```rust | ||
2413 | #![feature(crate_visibility_modifier)] | ||
2414 | |||
2415 | crate struct Foo { | ||
2416 | bar: usize, | ||
2417 | } | ||
2418 | ``` | ||
2419 | "##, | ||
2420 | }, | ||
2421 | LintCompletion { | ||
2422 | label: "doc_cfg", | ||
2423 | description: r##"# `doc_cfg` | ||
2424 | |||
2425 | The tracking issue for this feature is: [#43781] | ||
2426 | |||
2427 | ------ | ||
2428 | |||
2429 | The `doc_cfg` feature allows an API be documented as only available in some specific platforms. | ||
2430 | This attribute has two effects: | ||
2431 | |||
2432 | 1. In the annotated item's documentation, there will be a message saying "This is supported on | ||
2433 | (platform) only". | ||
2434 | |||
2435 | 2. The item's doc-tests will only run on the specific platform. | ||
2436 | |||
2437 | In addition to allowing the use of the `#[doc(cfg)]` attribute, this feature enables the use of a | ||
2438 | special conditional compilation flag, `#[cfg(doc)]`, set whenever building documentation on your | ||
2439 | crate. | ||
2440 | |||
2441 | This feature was introduced as part of PR [#43348] to allow the platform-specific parts of the | ||
2442 | standard library be documented. | ||
2443 | |||
2444 | ```rust | ||
2445 | #![feature(doc_cfg)] | ||
2446 | |||
2447 | #[cfg(any(windows, doc))] | ||
2448 | #[doc(cfg(windows))] | ||
2449 | /// The application's icon in the notification area (a.k.a. system tray). | ||
2450 | /// | ||
2451 | /// # Examples | ||
2452 | /// | ||
2453 | /// ```no_run | ||
2454 | /// extern crate my_awesome_ui_library; | ||
2455 | /// use my_awesome_ui_library::current_app; | ||
2456 | /// use my_awesome_ui_library::windows::notification; | ||
2457 | /// | ||
2458 | /// let icon = current_app().get::<notification::Icon>(); | ||
2459 | /// icon.show(); | ||
2460 | /// icon.show_message("Hello"); | ||
2461 | /// ``` | ||
2462 | pub struct Icon { | ||
2463 | // ... | ||
2464 | } | ||
2465 | ``` | ||
2466 | |||
2467 | [#43781]: https://github.com/rust-lang/rust/issues/43781 | ||
2468 | [#43348]: https://github.com/rust-lang/rust/issues/43348 | ||
2469 | "##, | ||
2470 | }, | ||
2471 | LintCompletion { | ||
2472 | label: "unsized_tuple_coercion", | ||
2473 | description: r##"# `unsized_tuple_coercion` | ||
2474 | 689 | ||
2475 | The tracking issue for this feature is: [#42877] | 690 | The tracking issue for this feature is: [#42202] |
2476 | 691 | ||
2477 | [#42877]: https://github.com/rust-lang/rust/issues/42877 | 692 | [#42202]: https://github.com/rust-lang/rust/issues/42202 |
2478 | 693 | ||
2479 | ------------------------ | 694 | ------------------------ |
2480 | 695 | ||
2481 | This is a part of [RFC0401]. According to the RFC, there should be an implementation like this: | 696 | The MSVC ABI on x86 Windows uses the `thiscall` calling convention for C++ |
2482 | 697 | instance methods by default; it is identical to the usual (C) calling | |
2483 | ```rust,ignore (partial-example) | 698 | convention on x86 Windows except that the first parameter of the method, |
2484 | impl<..., T, U: ?Sized> Unsized<(..., U)> for (..., T) where T: Unsized<U> {} | 699 | the `this` pointer, is passed in the ECX register. |
2485 | ``` | ||
2486 | |||
2487 | This implementation is currently gated behind `#[feature(unsized_tuple_coercion)]` to avoid insta-stability. Therefore you can use it like this: | ||
2488 | |||
2489 | ```rust | ||
2490 | #![feature(unsized_tuple_coercion)] | ||
2491 | |||
2492 | fn main() { | ||
2493 | let x : ([i32; 3], [i32; 3]) = ([1, 2, 3], [4, 5, 6]); | ||
2494 | let y : &([i32; 3], [i32]) = &x; | ||
2495 | assert_eq!(y.1[0], 4); | ||
2496 | } | ||
2497 | ``` | ||
2498 | |||
2499 | [RFC0401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md | ||
2500 | "##, | 700 | "##, |
2501 | }, | 701 | }, |
2502 | LintCompletion { | 702 | Lint { |
2503 | label: "no_sanitize", | 703 | label: "allocator_api", |
2504 | description: r##"# `no_sanitize` | 704 | description: r##"# `allocator_api` |
2505 | 705 | ||
2506 | The tracking issue for this feature is: [#39699] | 706 | The tracking issue for this feature is [#32838] |
2507 | 707 | ||
2508 | [#39699]: https://github.com/rust-lang/rust/issues/39699 | 708 | [#32838]: https://github.com/rust-lang/rust/issues/32838 |
2509 | 709 | ||
2510 | ------------------------ | 710 | ------------------------ |
2511 | 711 | ||
2512 | The `no_sanitize` attribute can be used to selectively disable sanitizer | 712 | Sometimes you want the memory for one collection to use a different |
2513 | instrumentation in an annotated function. This might be useful to: avoid | 713 | allocator than the memory for another collection. In this case, |
2514 | instrumentation overhead in a performance critical function, or avoid | 714 | replacing the global allocator is not a workable option. Instead, |
2515 | instrumenting code that contains constructs unsupported by given sanitizer. | 715 | you need to pass in an instance of an `AllocRef` to each collection |
2516 | 716 | for which you want a custom allocator. | |
2517 | The precise effect of this annotation depends on particular sanitizer in use. | ||
2518 | For example, with `no_sanitize(thread)`, the thread sanitizer will no longer | ||
2519 | instrument non-atomic store / load operations, but it will instrument atomic | ||
2520 | operations to avoid reporting false positives and provide meaning full stack | ||
2521 | traces. | ||
2522 | |||
2523 | ## Examples | ||
2524 | |||
2525 | ``` rust | ||
2526 | #![feature(no_sanitize)] | ||
2527 | 717 | ||
2528 | #[no_sanitize(address)] | 718 | TBD |
2529 | fn foo() { | ||
2530 | // ... | ||
2531 | } | ||
2532 | ``` | ||
2533 | "##, | 719 | "##, |
2534 | }, | 720 | }, |
2535 | LintCompletion { | 721 | Lint { |
2536 | label: "try_blocks", | 722 | label: "allocator_internals", |
2537 | description: r##"# `try_blocks` | 723 | description: r##"# `allocator_internals` |
2538 | |||
2539 | The tracking issue for this feature is: [#31436] | ||
2540 | 724 | ||
2541 | [#31436]: https://github.com/rust-lang/rust/issues/31436 | 725 | This feature does not have a tracking issue, it is an unstable implementation |
726 | detail of the `global_allocator` feature not intended for use outside the | ||
727 | compiler. | ||
2542 | 728 | ||
2543 | ------------------------ | 729 | ------------------------ |
2544 | |||
2545 | The `try_blocks` feature adds support for `try` blocks. A `try` | ||
2546 | block creates a new scope one can use the `?` operator in. | ||
2547 | |||
2548 | ```rust,edition2018 | ||
2549 | #![feature(try_blocks)] | ||
2550 | |||
2551 | use std::num::ParseIntError; | ||
2552 | |||
2553 | let result: Result<i32, ParseIntError> = try { | ||
2554 | "1".parse::<i32>()? | ||
2555 | + "2".parse::<i32>()? | ||
2556 | + "3".parse::<i32>()? | ||
2557 | }; | ||
2558 | assert_eq!(result, Ok(6)); | ||
2559 | |||
2560 | let result: Result<i32, ParseIntError> = try { | ||
2561 | "1".parse::<i32>()? | ||
2562 | + "foo".parse::<i32>()? | ||
2563 | + "3".parse::<i32>()? | ||
2564 | }; | ||
2565 | assert!(result.is_err()); | ||
2566 | ``` | ||
2567 | "##, | 730 | "##, |
2568 | }, | 731 | }, |
2569 | LintCompletion { | 732 | Lint { |
2570 | label: "transparent_unions", | 733 | label: "arbitrary_enum_discriminant", |
2571 | description: r##"# `transparent_unions` | 734 | description: r##"# `arbitrary_enum_discriminant` |
2572 | |||
2573 | The tracking issue for this feature is [#60405] | ||
2574 | |||
2575 | [#60405]: https://github.com/rust-lang/rust/issues/60405 | ||
2576 | |||
2577 | ---- | ||
2578 | 735 | ||
2579 | The `transparent_unions` feature allows you mark `union`s as | 736 | The tracking issue for this feature is: [#60553] |
2580 | `#[repr(transparent)]`. A `union` may be `#[repr(transparent)]` in exactly the | ||
2581 | same conditions in which a `struct` may be `#[repr(transparent)]` (generally, | ||
2582 | this means the `union` must have exactly one non-zero-sized field). Some | ||
2583 | concrete illustrations follow. | ||
2584 | 737 | ||
2585 | ```rust | 738 | [#60553]: https://github.com/rust-lang/rust/issues/60553 |
2586 | #![feature(transparent_unions)] | ||
2587 | 739 | ||
2588 | // This union has the same representation as `f32`. | 740 | ------------------------ |
2589 | #[repr(transparent)] | ||
2590 | union SingleFieldUnion { | ||
2591 | field: f32, | ||
2592 | } | ||
2593 | 741 | ||
2594 | // This union has the same representation as `usize`. | 742 | The `arbitrary_enum_discriminant` feature permits tuple-like and |
2595 | #[repr(transparent)] | 743 | struct-like enum variants with `#[repr(<int-type>)]` to have explicit discriminants. |
2596 | union MultiFieldUnion { | ||
2597 | field: usize, | ||
2598 | nothing: (), | ||
2599 | } | ||
2600 | ``` | ||
2601 | 744 | ||
2602 | For consistency with transparent `struct`s, `union`s must have exactly one | 745 | ## Examples |
2603 | non-zero-sized field. If all fields are zero-sized, the `union` must not be | ||
2604 | `#[repr(transparent)]`: | ||
2605 | 746 | ||
2606 | ```rust | 747 | ```rust |
2607 | #![feature(transparent_unions)] | 748 | #![feature(arbitrary_enum_discriminant)] |
2608 | 749 | ||
2609 | // This (non-transparent) union is already valid in stable Rust: | 750 | #[allow(dead_code)] |
2610 | pub union GoodUnion { | 751 | #[repr(u8)] |
2611 | pub nothing: (), | 752 | enum Enum { |
753 | Unit = 3, | ||
754 | Tuple(u16) = 2, | ||
755 | Struct { | ||
756 | a: u8, | ||
757 | b: u16, | ||
758 | } = 1, | ||
2612 | } | 759 | } |
2613 | 760 | ||
2614 | // Error: transparent union needs exactly one non-zero-sized field, but has 0 | 761 | impl Enum { |
2615 | // #[repr(transparent)] | 762 | fn tag(&self) -> u8 { |
2616 | // pub union BadUnion { | 763 | unsafe { *(self as *const Self as *const u8) } |
2617 | // pub nothing: (), | 764 | } |
2618 | // } | ||
2619 | ``` | ||
2620 | |||
2621 | The one exception is if the `union` is generic over `T` and has a field of type | ||
2622 | `T`, it may be `#[repr(transparent)]` even if `T` is a zero-sized type: | ||
2623 | |||
2624 | ```rust | ||
2625 | #![feature(transparent_unions)] | ||
2626 | |||
2627 | // This union has the same representation as `T`. | ||
2628 | #[repr(transparent)] | ||
2629 | pub union GenericUnion<T: Copy> { // Unions with non-`Copy` fields are unstable. | ||
2630 | pub field: T, | ||
2631 | pub nothing: (), | ||
2632 | } | 765 | } |
2633 | 766 | ||
2634 | // This is okay even though `()` is a zero-sized type. | 767 | assert_eq!(3, Enum::Unit.tag()); |
2635 | pub const THIS_IS_OKAY: GenericUnion<()> = GenericUnion { field: () }; | 768 | assert_eq!(2, Enum::Tuple(5).tag()); |
2636 | ``` | 769 | assert_eq!(1, Enum::Struct{a: 7, b: 11}.tag()); |
2637 | |||
2638 | Like transarent `struct`s, a transparent `union` of type `U` has the same | ||
2639 | layout, size, and ABI as its single non-ZST field. If it is generic over a type | ||
2640 | `T`, and all its fields are ZSTs except for exactly one field of type `T`, then | ||
2641 | it has the same layout and ABI as `T` (even if `T` is a ZST when monomorphized). | ||
2642 | |||
2643 | Like transparent `struct`s, transparent `union`s are FFI-safe if and only if | ||
2644 | their underlying representation type is also FFI-safe. | ||
2645 | |||
2646 | A `union` may not be eligible for the same nonnull-style optimizations that a | ||
2647 | `struct` or `enum` (with the same fields) are eligible for. Adding | ||
2648 | `#[repr(transparent)]` to `union` does not change this. To give a more concrete | ||
2649 | example, it is unspecified whether `size_of::<T>()` is equal to | ||
2650 | `size_of::<Option<T>>()`, where `T` is a `union` (regardless of whether or not | ||
2651 | it is transparent). The Rust compiler is free to perform this optimization if | ||
2652 | possible, but is not required to, and different compiler versions may differ in | ||
2653 | their application of these optimizations. | ||
2654 | "##, | ||
2655 | }, | ||
2656 | LintCompletion { | ||
2657 | label: "const_eval_limit", | ||
2658 | description: r##"# `const_eval_limit` | ||
2659 | |||
2660 | The tracking issue for this feature is: [#67217] | ||
2661 | |||
2662 | [#67217]: https://github.com/rust-lang/rust/issues/67217 | ||
2663 | |||
2664 | The `const_eval_limit` allows someone to limit the evaluation steps the CTFE undertakes to evaluate a `const fn`. | ||
2665 | "##, | ||
2666 | }, | ||
2667 | LintCompletion { | ||
2668 | label: "link_args", | ||
2669 | description: r##"# `link_args` | ||
2670 | |||
2671 | The tracking issue for this feature is: [#29596] | ||
2672 | |||
2673 | [#29596]: https://github.com/rust-lang/rust/issues/29596 | ||
2674 | |||
2675 | ------------------------ | ||
2676 | |||
2677 | You can tell `rustc` how to customize linking, and that is via the `link_args` | ||
2678 | attribute. This attribute is applied to `extern` blocks and specifies raw flags | ||
2679 | which need to get passed to the linker when producing an artifact. An example | ||
2680 | usage would be: | ||
2681 | |||
2682 | ```rust,no_run | ||
2683 | #![feature(link_args)] | ||
2684 | |||
2685 | #[link_args = "-foo -bar -baz"] | ||
2686 | extern "C" {} | ||
2687 | # fn main() {} | ||
2688 | ``` | 770 | ``` |
2689 | |||
2690 | Note that this feature is currently hidden behind the `feature(link_args)` gate | ||
2691 | because this is not a sanctioned way of performing linking. Right now `rustc` | ||
2692 | shells out to the system linker (`gcc` on most systems, `link.exe` on MSVC), so | ||
2693 | it makes sense to provide extra command line arguments, but this will not | ||
2694 | always be the case. In the future `rustc` may use LLVM directly to link native | ||
2695 | libraries, in which case `link_args` will have no meaning. You can achieve the | ||
2696 | same effect as the `link_args` attribute with the `-C link-args` argument to | ||
2697 | `rustc`. | ||
2698 | |||
2699 | It is highly recommended to *not* use this attribute, and rather use the more | ||
2700 | formal `#[link(...)]` attribute on `extern` blocks instead. | ||
2701 | "##, | ||
2702 | }, | ||
2703 | LintCompletion { | ||
2704 | label: "internal_output_capture", | ||
2705 | description: r##"# `internal_output_capture` | ||
2706 | |||
2707 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2708 | |||
2709 | ------------------------ | ||
2710 | "##, | ||
2711 | }, | ||
2712 | LintCompletion { | ||
2713 | label: "windows_handle", | ||
2714 | description: r##"# `windows_handle` | ||
2715 | |||
2716 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2717 | |||
2718 | ------------------------ | ||
2719 | "##, | 771 | "##, |
2720 | }, | 772 | }, |
2721 | LintCompletion { | 773 | Lint { |
2722 | label: "asm", | 774 | label: "asm", |
2723 | description: r##"# `asm` | 775 | description: r##"# `asm` |
2724 | 776 | ||
@@ -2748,6 +800,7 @@ Inline assembly is currently supported on the following architectures: | |||
2748 | - AArch64 | 800 | - AArch64 |
2749 | - RISC-V | 801 | - RISC-V |
2750 | - NVPTX | 802 | - NVPTX |
803 | - PowerPC | ||
2751 | - Hexagon | 804 | - Hexagon |
2752 | - MIPS32r2 and MIPS64r2 | 805 | - MIPS32r2 and MIPS64r2 |
2753 | - wasm32 | 806 | - wasm32 |
@@ -2757,7 +810,7 @@ Inline assembly is currently supported on the following architectures: | |||
2757 | Let us start with the simplest possible example: | 810 | Let us start with the simplest possible example: |
2758 | 811 | ||
2759 | ```rust,allow_fail | 812 | ```rust,allow_fail |
2760 | # #![feature(asm)] | 813 | #![feature(asm)] |
2761 | unsafe { | 814 | unsafe { |
2762 | asm!("nop"); | 815 | asm!("nop"); |
2763 | } | 816 | } |
@@ -2774,7 +827,7 @@ Now inserting an instruction that does nothing is rather boring. Let us do somet | |||
2774 | actually acts on data: | 827 | actually acts on data: |
2775 | 828 | ||
2776 | ```rust,allow_fail | 829 | ```rust,allow_fail |
2777 | # #![feature(asm)] | 830 | #![feature(asm)] |
2778 | let x: u64; | 831 | let x: u64; |
2779 | unsafe { | 832 | unsafe { |
2780 | asm!("mov {}, 5", out(reg) x); | 833 | asm!("mov {}, 5", out(reg) x); |
@@ -2796,7 +849,7 @@ the template and will read the variable from there after the inline assembly fin | |||
2796 | Let us see another example that also uses an input: | 849 | Let us see another example that also uses an input: |
2797 | 850 | ||
2798 | ```rust,allow_fail | 851 | ```rust,allow_fail |
2799 | # #![feature(asm)] | 852 | #![feature(asm)] |
2800 | let i: u64 = 3; | 853 | let i: u64 = 3; |
2801 | let o: u64; | 854 | let o: u64; |
2802 | unsafe { | 855 | unsafe { |
@@ -2836,7 +889,7 @@ readability, and allows reordering instructions without changing the argument or | |||
2836 | We can further refine the above example to avoid the `mov` instruction: | 889 | We can further refine the above example to avoid the `mov` instruction: |
2837 | 890 | ||
2838 | ```rust,allow_fail | 891 | ```rust,allow_fail |
2839 | # #![feature(asm)] | 892 | #![feature(asm)] |
2840 | let mut x: u64 = 3; | 893 | let mut x: u64 = 3; |
2841 | unsafe { | 894 | unsafe { |
2842 | asm!("add {0}, {number}", inout(reg) x, number = const 5); | 895 | asm!("add {0}, {number}", inout(reg) x, number = const 5); |
@@ -2850,7 +903,7 @@ This is different from specifying an input and output separately in that it is g | |||
2850 | It is also possible to specify different variables for the input and output parts of an `inout` operand: | 903 | It is also possible to specify different variables for the input and output parts of an `inout` operand: |
2851 | 904 | ||
2852 | ```rust,allow_fail | 905 | ```rust,allow_fail |
2853 | # #![feature(asm)] | 906 | #![feature(asm)] |
2854 | let x: u64 = 3; | 907 | let x: u64 = 3; |
2855 | let y: u64; | 908 | let y: u64; |
2856 | unsafe { | 909 | unsafe { |
@@ -2872,7 +925,7 @@ There is also a `inlateout` variant of this specifier. | |||
2872 | Here is an example where `inlateout` *cannot* be used: | 925 | Here is an example where `inlateout` *cannot* be used: |
2873 | 926 | ||
2874 | ```rust,allow_fail | 927 | ```rust,allow_fail |
2875 | # #![feature(asm)] | 928 | #![feature(asm)] |
2876 | let mut a: u64 = 4; | 929 | let mut a: u64 = 4; |
2877 | let b: u64 = 4; | 930 | let b: u64 = 4; |
2878 | let c: u64 = 4; | 931 | let c: u64 = 4; |
@@ -2893,7 +946,7 @@ Here the compiler is free to allocate the same register for inputs `b` and `c` s | |||
2893 | However the following example can use `inlateout` since the output is only modified after all input registers have been read: | 946 | However the following example can use `inlateout` since the output is only modified after all input registers have been read: |
2894 | 947 | ||
2895 | ```rust,allow_fail | 948 | ```rust,allow_fail |
2896 | # #![feature(asm)] | 949 | #![feature(asm)] |
2897 | let mut a: u64 = 4; | 950 | let mut a: u64 = 4; |
2898 | let b: u64 = 4; | 951 | let b: u64 = 4; |
2899 | unsafe { | 952 | unsafe { |
@@ -2912,7 +965,7 @@ While `reg` is generally available on any architecture, these are highly archite | |||
2912 | among others can be addressed by their name. | 965 | among others can be addressed by their name. |
2913 | 966 | ||
2914 | ```rust,allow_fail,no_run | 967 | ```rust,allow_fail,no_run |
2915 | # #![feature(asm)] | 968 | #![feature(asm)] |
2916 | let cmd = 0xd1; | 969 | let cmd = 0xd1; |
2917 | unsafe { | 970 | unsafe { |
2918 | asm!("out 0x64, eax", in("eax") cmd); | 971 | asm!("out 0x64, eax", in("eax") cmd); |
@@ -2928,7 +981,7 @@ Note that unlike other operand types, explicit register operands cannot be used | |||
2928 | Consider this example which uses the x86 `mul` instruction: | 981 | Consider this example which uses the x86 `mul` instruction: |
2929 | 982 | ||
2930 | ```rust,allow_fail | 983 | ```rust,allow_fail |
2931 | # #![feature(asm)] | 984 | #![feature(asm)] |
2932 | fn mul(a: u64, b: u64) -> u128 { | 985 | fn mul(a: u64, b: u64) -> u128 { |
2933 | let lo: u64; | 986 | let lo: u64; |
2934 | let hi: u64; | 987 | let hi: u64; |
@@ -2964,7 +1017,7 @@ We need to tell the compiler about this since it may need to save and restore th | |||
2964 | around the inline assembly block. | 1017 | around the inline assembly block. |
2965 | 1018 | ||
2966 | ```rust,allow_fail | 1019 | ```rust,allow_fail |
2967 | # #![feature(asm)] | 1020 | #![feature(asm)] |
2968 | let ebx: u32; | 1021 | let ebx: u32; |
2969 | let ecx: u32; | 1022 | let ecx: u32; |
2970 | 1023 | ||
@@ -2994,7 +1047,7 @@ However we still need to tell the compiler that `eax` and `edx` have been modifi | |||
2994 | This can also be used with a general register class (e.g. `reg`) to obtain a scratch register for use inside the asm code: | 1047 | This can also be used with a general register class (e.g. `reg`) to obtain a scratch register for use inside the asm code: |
2995 | 1048 | ||
2996 | ```rust,allow_fail | 1049 | ```rust,allow_fail |
2997 | # #![feature(asm)] | 1050 | #![feature(asm)] |
2998 | // Multiply x by 6 using shifts and adds | 1051 | // Multiply x by 6 using shifts and adds |
2999 | let mut x: u64 = 4; | 1052 | let mut x: u64 = 4; |
3000 | unsafe { | 1053 | unsafe { |
@@ -3016,7 +1069,7 @@ A special operand type, `sym`, allows you to use the symbol name of a `fn` or `s | |||
3016 | This allows you to call a function or access a global variable without needing to keep its address in a register. | 1069 | This allows you to call a function or access a global variable without needing to keep its address in a register. |
3017 | 1070 | ||
3018 | ```rust,allow_fail | 1071 | ```rust,allow_fail |
3019 | # #![feature(asm)] | 1072 | #![feature(asm)] |
3020 | extern "C" fn foo(arg: i32) { | 1073 | extern "C" fn foo(arg: i32) { |
3021 | println!("arg = {}", arg); | 1074 | println!("arg = {}", arg); |
3022 | } | 1075 | } |
@@ -3028,13 +1081,19 @@ fn call_foo(arg: i32) { | |||
3028 | sym foo, | 1081 | sym foo, |
3029 | // 1st argument in rdi, which is caller-saved | 1082 | // 1st argument in rdi, which is caller-saved |
3030 | inout("rdi") arg => _, | 1083 | inout("rdi") arg => _, |
3031 | // All caller-saved registers must be marked as clobberred | 1084 | // All caller-saved registers must be marked as clobbered |
3032 | out("rax") _, out("rcx") _, out("rdx") _, out("rsi") _, | 1085 | out("rax") _, out("rcx") _, out("rdx") _, out("rsi") _, |
3033 | out("r8") _, out("r9") _, out("r10") _, out("r11") _, | 1086 | out("r8") _, out("r9") _, out("r10") _, out("r11") _, |
3034 | out("xmm0") _, out("xmm1") _, out("xmm2") _, out("xmm3") _, | 1087 | out("xmm0") _, out("xmm1") _, out("xmm2") _, out("xmm3") _, |
3035 | out("xmm4") _, out("xmm5") _, out("xmm6") _, out("xmm7") _, | 1088 | out("xmm4") _, out("xmm5") _, out("xmm6") _, out("xmm7") _, |
3036 | out("xmm8") _, out("xmm9") _, out("xmm10") _, out("xmm11") _, | 1089 | out("xmm8") _, out("xmm9") _, out("xmm10") _, out("xmm11") _, |
3037 | out("xmm12") _, out("xmm13") _, out("xmm14") _, out("xmm15") _, | 1090 | out("xmm12") _, out("xmm13") _, out("xmm14") _, out("xmm15") _, |
1091 | // Also mark AVX-512 registers as clobbered. This is accepted by the | ||
1092 | // compiler even if AVX-512 is not enabled on the current target. | ||
1093 | out("xmm16") _, out("xmm17") _, out("xmm18") _, out("xmm19") _, | ||
1094 | out("xmm20") _, out("xmm21") _, out("xmm22") _, out("xmm23") _, | ||
1095 | out("xmm24") _, out("xmm25") _, out("xmm26") _, out("xmm27") _, | ||
1096 | out("xmm28") _, out("xmm29") _, out("xmm30") _, out("xmm31") _, | ||
3038 | ) | 1097 | ) |
3039 | } | 1098 | } |
3040 | } | 1099 | } |
@@ -3052,7 +1111,7 @@ By default the compiler will always choose the name that refers to the full regi | |||
3052 | This default can be overriden by using modifiers on the template string operands, just like you would with format strings: | 1111 | This default can be overriden by using modifiers on the template string operands, just like you would with format strings: |
3053 | 1112 | ||
3054 | ```rust,allow_fail | 1113 | ```rust,allow_fail |
3055 | # #![feature(asm)] | 1114 | #![feature(asm)] |
3056 | let mut x: u16 = 0xab; | 1115 | let mut x: u16 = 0xab; |
3057 | 1116 | ||
3058 | unsafe { | 1117 | unsafe { |
@@ -3077,7 +1136,7 @@ For example, in x86/x86_64 and intel assembly syntax, you should wrap inputs/out | |||
3077 | to indicate they are memory operands: | 1136 | to indicate they are memory operands: |
3078 | 1137 | ||
3079 | ```rust,allow_fail | 1138 | ```rust,allow_fail |
3080 | # #![feature(asm, llvm_asm)] | 1139 | #![feature(asm, llvm_asm)] |
3081 | # fn load_fpu_control_word(control: u16) { | 1140 | # fn load_fpu_control_word(control: u16) { |
3082 | unsafe { | 1141 | unsafe { |
3083 | asm!("fldcw [{}]", in(reg) &control, options(nostack)); | 1142 | asm!("fldcw [{}]", in(reg) &control, options(nostack)); |
@@ -3088,6 +1147,43 @@ unsafe { | |||
3088 | # } | 1147 | # } |
3089 | ``` | 1148 | ``` |
3090 | 1149 | ||
1150 | ## Labels | ||
1151 | |||
1152 | The compiler is allowed to instantiate multiple copies an `asm!` block, for example when the function containing it is inlined in multiple places. As a consequence, you should only use GNU assembler [local labels] inside inline assembly code. Defining symbols in assembly code may lead to assembler and/or linker errors due to duplicate symbol definitions. | ||
1153 | |||
1154 | Moreover, due to [an llvm bug], you shouldn't use labels exclusively made of `0` and `1` digits, e.g. `0`, `11` or `101010`, as they may end up being interpreted as binary values. | ||
1155 | |||
1156 | ```rust,allow_fail | ||
1157 | #![feature(asm)] | ||
1158 | |||
1159 | let mut a = 0; | ||
1160 | unsafe { | ||
1161 | asm!( | ||
1162 | "mov {0}, 10", | ||
1163 | "2:", | ||
1164 | "sub {0}, 1", | ||
1165 | "cmp {0}, 3", | ||
1166 | "jle 2f", | ||
1167 | "jmp 2b", | ||
1168 | "2:", | ||
1169 | "add {0}, 2", | ||
1170 | out(reg) a | ||
1171 | ); | ||
1172 | } | ||
1173 | assert_eq!(a, 5); | ||
1174 | ``` | ||
1175 | |||
1176 | This will decrement the `{0}` register value from 10 to 3, then add 2 and store it in `a`. | ||
1177 | |||
1178 | This example show a few thing: | ||
1179 | |||
1180 | First that the same number can be used as a label multiple times in the same inline block. | ||
1181 | |||
1182 | Second, that when a numeric label is used as a reference (as an instruction operand, for example), the suffixes b (“backward”) or f (“forward”) should be added to the numeric label. It will then refer to the nearest label defined by this number in this direction. | ||
1183 | |||
1184 | [local labels]: https://sourceware.org/binutils/docs/as/Symbol-Names.html#Local-Labels | ||
1185 | [an llvm bug]: https://bugs.llvm.org/show_bug.cgi?id=36144 | ||
1186 | |||
3091 | ## Options | 1187 | ## Options |
3092 | 1188 | ||
3093 | By default, an inline assembly block is treated the same way as an external FFI function call with a custom calling convention: it may read/write memory, have observable side effects, etc. However in many cases, it is desirable to give the compiler more information about what the assembly code is actually doing so that it can optimize better. | 1189 | By default, an inline assembly block is treated the same way as an external FFI function call with a custom calling convention: it may read/write memory, have observable side effects, etc. However in many cases, it is desirable to give the compiler more information about what the assembly code is actually doing so that it can optimize better. |
@@ -3095,7 +1191,7 @@ By default, an inline assembly block is treated the same way as an external FFI | |||
3095 | Let's take our previous example of an `add` instruction: | 1191 | Let's take our previous example of an `add` instruction: |
3096 | 1192 | ||
3097 | ```rust,allow_fail | 1193 | ```rust,allow_fail |
3098 | # #![feature(asm)] | 1194 | #![feature(asm)] |
3099 | let mut a: u64 = 4; | 1195 | let mut a: u64 = 4; |
3100 | let b: u64 = 4; | 1196 | let b: u64 = 4; |
3101 | unsafe { | 1197 | unsafe { |
@@ -3138,7 +1234,7 @@ options := "options(" option *["," option] [","] ")" | |||
3138 | asm := "asm!(" format_string *("," format_string) *("," [ident "="] operand) ["," options] [","] ")" | 1234 | asm := "asm!(" format_string *("," format_string) *("," [ident "="] operand) ["," options] [","] ")" |
3139 | ``` | 1235 | ``` |
3140 | 1236 | ||
3141 | The macro will initially be supported only on ARM, AArch64, Hexagon, x86, x86-64 and RISC-V targets. Support for more targets may be added in the future. The compiler will emit an error if `asm!` is used on an unsupported target. | 1237 | The macro will initially be supported only on ARM, AArch64, Hexagon, PowerPC, x86, x86-64 and RISC-V targets. Support for more targets may be added in the future. The compiler will emit an error if `asm!` is used on an unsupported target. |
3142 | 1238 | ||
3143 | [format-syntax]: https://doc.rust-lang.org/std/fmt/#syntax | 1239 | [format-syntax]: https://doc.rust-lang.org/std/fmt/#syntax |
3144 | 1240 | ||
@@ -3187,7 +1283,7 @@ Several types of operands are supported: | |||
3187 | - Identical to `inout` except that the register allocator can reuse a register allocated to an `in` (this can happen if the compiler knows the `in` has the same initial value as the `inlateout`). | 1283 | - Identical to `inout` except that the register allocator can reuse a register allocated to an `in` (this can happen if the compiler knows the `in` has the same initial value as the `inlateout`). |
3188 | - You should only write to the register after all inputs are read, otherwise you may clobber an input. | 1284 | - You should only write to the register after all inputs are read, otherwise you may clobber an input. |
3189 | * `const <expr>` | 1285 | * `const <expr>` |
3190 | - `<expr>` must be an integer or floating-point constant expression. | 1286 | - `<expr>` must be an integer constant expression. |
3191 | - The value of the expression is formatted as a string and substituted directly into the asm template string. | 1287 | - The value of the expression is formatted as a string and substituted directly into the asm template string. |
3192 | * `sym <path>` | 1288 | * `sym <path>` |
3193 | - `<path>` must refer to a `fn` or `static`. | 1289 | - `<path>` must refer to a `fn` or `static`. |
@@ -3214,20 +1310,20 @@ Here is the list of currently supported register classes: | |||
3214 | 1310 | ||
3215 | | Architecture | Register class | Registers | LLVM constraint code | | 1311 | | Architecture | Register class | Registers | LLVM constraint code | |
3216 | | ------------ | -------------- | --------- | -------------------- | | 1312 | | ------------ | -------------- | --------- | -------------------- | |
3217 | | x86 | `reg` | `ax`, `bx`, `cx`, `dx`, `si`, `di`, `r[8-15]` (x86-64 only) | `r` | | 1313 | | x86 | `reg` | `ax`, `bx`, `cx`, `dx`, `si`, `di`, `bp`, `r[8-15]` (x86-64 only) | `r` | |
3218 | | x86 | `reg_abcd` | `ax`, `bx`, `cx`, `dx` | `Q` | | 1314 | | x86 | `reg_abcd` | `ax`, `bx`, `cx`, `dx` | `Q` | |
3219 | | x86-32 | `reg_byte` | `al`, `bl`, `cl`, `dl`, `ah`, `bh`, `ch`, `dh` | `q` | | 1315 | | x86-32 | `reg_byte` | `al`, `bl`, `cl`, `dl`, `ah`, `bh`, `ch`, `dh` | `q` | |
3220 | | x86-64 | `reg_byte` | `al`, `bl`, `cl`, `dl`, `sil`, `dil`, `r[8-15]b`, `ah`\*, `bh`\*, `ch`\*, `dh`\* | `q` | | 1316 | | x86-64 | `reg_byte`\* | `al`, `bl`, `cl`, `dl`, `sil`, `dil`, `bpl`, `r[8-15]b` | `q` | |
3221 | | x86 | `xmm_reg` | `xmm[0-7]` (x86) `xmm[0-15]` (x86-64) | `x` | | 1317 | | x86 | `xmm_reg` | `xmm[0-7]` (x86) `xmm[0-15]` (x86-64) | `x` | |
3222 | | x86 | `ymm_reg` | `ymm[0-7]` (x86) `ymm[0-15]` (x86-64) | `x` | | 1318 | | x86 | `ymm_reg` | `ymm[0-7]` (x86) `ymm[0-15]` (x86-64) | `x` | |
3223 | | x86 | `zmm_reg` | `zmm[0-7]` (x86) `zmm[0-31]` (x86-64) | `v` | | 1319 | | x86 | `zmm_reg` | `zmm[0-7]` (x86) `zmm[0-31]` (x86-64) | `v` | |
3224 | | x86 | `kreg` | `k[1-7]` | `Yk` | | 1320 | | x86 | `kreg` | `k[1-7]` | `Yk` | |
3225 | | AArch64 | `reg` | `x[0-28]`, `x30` | `r` | | 1321 | | AArch64 | `reg` | `x[0-30]` | `r` | |
3226 | | AArch64 | `vreg` | `v[0-31]` | `w` | | 1322 | | AArch64 | `vreg` | `v[0-31]` | `w` | |
3227 | | AArch64 | `vreg_low16` | `v[0-15]` | `x` | | 1323 | | AArch64 | `vreg_low16` | `v[0-15]` | `x` | |
3228 | | ARM | `reg` | `r[0-5]` `r7`\*, `r[8-10]`, `r11`\*, `r12`, `r14` | `r` | | 1324 | | ARM | `reg` | `r[0-12]`, `r14` | `r` | |
3229 | | ARM (Thumb) | `reg_thumb` | `r[0-r7]` | `l` | | 1325 | | ARM (Thumb) | `reg_thumb` | `r[0-r7]` | `l` | |
3230 | | ARM (ARM) | `reg_thumb` | `r[0-r10]`, `r12`, `r14` | `l` | | 1326 | | ARM (ARM) | `reg_thumb` | `r[0-r12]`, `r14` | `l` | |
3231 | | ARM | `sreg` | `s[0-31]` | `t` | | 1327 | | ARM | `sreg` | `s[0-31]` | `t` | |
3232 | | ARM | `sreg_low16` | `s[0-15]` | `x` | | 1328 | | ARM | `sreg_low16` | `s[0-15]` | `x` | |
3233 | | ARM | `dreg` | `d[0-31]` | `w` | | 1329 | | ARM | `dreg` | `d[0-31]` | `w` | |
@@ -3244,17 +1340,18 @@ Here is the list of currently supported register classes: | |||
3244 | | RISC-V | `reg` | `x1`, `x[5-7]`, `x[9-15]`, `x[16-31]` (non-RV32E) | `r` | | 1340 | | RISC-V | `reg` | `x1`, `x[5-7]`, `x[9-15]`, `x[16-31]` (non-RV32E) | `r` | |
3245 | | RISC-V | `freg` | `f[0-31]` | `f` | | 1341 | | RISC-V | `freg` | `f[0-31]` | `f` | |
3246 | | Hexagon | `reg` | `r[0-28]` | `r` | | 1342 | | Hexagon | `reg` | `r[0-28]` | `r` | |
1343 | | PowerPC | `reg` | `r[0-31]` | `r` | | ||
1344 | | PowerPC | `reg_nonzero` | | `r[1-31]` | `b` | | ||
1345 | | PowerPC | `freg` | `f[0-31]` | `f` | | ||
3247 | | wasm32 | `local` | None\* | `r` | | 1346 | | wasm32 | `local` | None\* | `r` | |
3248 | 1347 | ||
3249 | > **Note**: On x86 we treat `reg_byte` differently from `reg` because the compiler can allocate `al` and `ah` separately whereas `reg` reserves the whole register. | 1348 | > **Note**: On x86 we treat `reg_byte` differently from `reg` because the compiler can allocate `al` and `ah` separately whereas `reg` reserves the whole register. |
3250 | > | 1349 | > |
3251 | > Note #2: On x86-64 the high byte registers (e.g. `ah`) are only available when used as an explicit register. Specifying the `reg_byte` register class for an operand will always allocate a low byte register. | 1350 | > Note #2: On x86-64 the high byte registers (e.g. `ah`) are not available in the `reg_byte` register class. |
3252 | > | 1351 | > |
3253 | > Note #3: NVPTX doesn't have a fixed register set, so named registers are not supported. | 1352 | > Note #3: NVPTX doesn't have a fixed register set, so named registers are not supported. |
3254 | > | 1353 | > |
3255 | > Note #4: On ARM the frame pointer is either `r7` or `r11` depending on the platform. | 1354 | > Note #4: WebAssembly doesn't have registers, so named registers are not supported. |
3256 | > | ||
3257 | > Note #5: WebAssembly doesn't have registers, so named registers are not supported. | ||
3258 | 1355 | ||
3259 | Additional register classes may be added in the future based on demand (e.g. MMX, x87, etc). | 1356 | Additional register classes may be added in the future based on demand (e.g. MMX, x87, etc). |
3260 | 1357 | ||
@@ -3288,6 +1385,9 @@ Each register class has constraints on which value types they can be used with. | |||
3288 | | RISC-V | `freg` | `f` | `f32` | | 1385 | | RISC-V | `freg` | `f` | `f32` | |
3289 | | RISC-V | `freg` | `d` | `f64` | | 1386 | | RISC-V | `freg` | `d` | `f64` | |
3290 | | Hexagon | `reg` | None | `i8`, `i16`, `i32`, `f32` | | 1387 | | Hexagon | `reg` | None | `i8`, `i16`, `i32`, `f32` | |
1388 | | PowerPC | `reg` | None | `i8`, `i16`, `i32` | | ||
1389 | | PowerPC | `reg_nonzero` | None | `i8`, `i16`, `i32` | | ||
1390 | | PowerPC | `freg` | None | `f32`, `f64` | | ||
3291 | | wasm32 | `local` | None | `i8` `i16` `i32` `i64` `f32` `f64` | | 1391 | | wasm32 | `local` | None | `i8` `i16` `i32` `i64` `f32` `f64` | |
3292 | 1392 | ||
3293 | > **Note**: For the purposes of the above table pointers, function pointers and `isize`/`usize` are treated as the equivalent integer type (`i16`/`i32`/`i64` depending on the target). | 1393 | > **Note**: For the purposes of the above table pointers, function pointers and `isize`/`usize` are treated as the equivalent integer type (`i16`/`i32`/`i64` depending on the target). |
@@ -3356,13 +1456,14 @@ Some registers cannot be used for input or output operands: | |||
3356 | | All | `sp` | The stack pointer must be restored to its original value at the end of an asm code block. | | 1456 | | All | `sp` | The stack pointer must be restored to its original value at the end of an asm code block. | |
3357 | | All | `bp` (x86), `x29` (AArch64), `x8` (RISC-V), `fr` (Hexagon), `$fp` (MIPS) | The frame pointer cannot be used as an input or output. | | 1457 | | All | `bp` (x86), `x29` (AArch64), `x8` (RISC-V), `fr` (Hexagon), `$fp` (MIPS) | The frame pointer cannot be used as an input or output. | |
3358 | | ARM | `r7` or `r11` | On ARM the frame pointer can be either `r7` or `r11` depending on the target. The frame pointer cannot be used as an input or output. | | 1458 | | ARM | `r7` or `r11` | On ARM the frame pointer can be either `r7` or `r11` depending on the target. The frame pointer cannot be used as an input or output. | |
3359 | | ARM | `r6` | `r6` is used internally by LLVM as a base pointer and therefore cannot be used as an input or output. | | 1459 | | All | `si` (x86-32), `bx` (x86-64), `r6` (ARM), `x19` (AArch64), `r19` (Hexagon), `x9` (RISC-V) | This is used internally by LLVM as a "base pointer" for functions with complex stack frames. | |
3360 | | x86 | `k0` | This is a constant zero register which can't be modified. | | 1460 | | x86 | `k0` | This is a constant zero register which can't be modified. | |
3361 | | x86 | `ip` | This is the program counter, not a real register. | | 1461 | | x86 | `ip` | This is the program counter, not a real register. | |
3362 | | x86 | `mm[0-7]` | MMX registers are not currently supported (but may be in the future). | | 1462 | | x86 | `mm[0-7]` | MMX registers are not currently supported (but may be in the future). | |
3363 | | x86 | `st([0-7])` | x87 registers are not currently supported (but may be in the future). | | 1463 | | x86 | `st([0-7])` | x87 registers are not currently supported (but may be in the future). | |
3364 | | AArch64 | `xzr` | This is a constant zero register which can't be modified. | | 1464 | | AArch64 | `xzr` | This is a constant zero register which can't be modified. | |
3365 | | ARM | `pc` | This is the program counter, not a real register. | | 1465 | | ARM | `pc` | This is the program counter, not a real register. | |
1466 | | ARM | `r9` | This is a reserved register on some ARM targets. | | ||
3366 | | MIPS | `$0` or `$zero` | This is a constant zero register which can't be modified. | | 1467 | | MIPS | `$0` or `$zero` | This is a constant zero register which can't be modified. | |
3367 | | MIPS | `$1` or `$at` | Reserved for assembler. | | 1468 | | MIPS | `$1` or `$at` | Reserved for assembler. | |
3368 | | MIPS | `$26`/`$k0`, `$27`/`$k1` | OS-reserved registers. | | 1469 | | MIPS | `$26`/`$k0`, `$27`/`$k1` | OS-reserved registers. | |
@@ -3372,9 +1473,10 @@ Some registers cannot be used for input or output operands: | |||
3372 | | RISC-V | `gp`, `tp` | These registers are reserved and cannot be used as inputs or outputs. | | 1473 | | RISC-V | `gp`, `tp` | These registers are reserved and cannot be used as inputs or outputs. | |
3373 | | Hexagon | `lr` | This is the link register which cannot be used as an input or output. | | 1474 | | Hexagon | `lr` | This is the link register which cannot be used as an input or output. | |
3374 | 1475 | ||
3375 | In some cases LLVM will allocate a "reserved register" for `reg` operands even though this register cannot be explicitly specified. Assembly code making use of reserved registers should be careful since `reg` operands may alias with those registers. Reserved registers are: | 1476 | In some cases LLVM will allocate a "reserved register" for `reg` operands even though this register cannot be explicitly specified. Assembly code making use of reserved registers should be careful since `reg` operands may alias with those registers. Reserved registers are the frame pointer and base pointer |
3376 | - The frame pointer on all architectures. | 1477 | - The frame pointer and LLVM base pointer on all architectures. |
3377 | - `r6` on ARM. | 1478 | - `r9` on ARM. |
1479 | - `x18` on AArch64. | ||
3378 | 1480 | ||
3379 | ## Template modifiers | 1481 | ## Template modifiers |
3380 | 1482 | ||
@@ -3423,6 +1525,9 @@ The supported modifiers are a subset of LLVM's (and GCC's) [asm template argumen | |||
3423 | | RISC-V | `reg` | None | `x1` | None | | 1525 | | RISC-V | `reg` | None | `x1` | None | |
3424 | | RISC-V | `freg` | None | `f0` | None | | 1526 | | RISC-V | `freg` | None | `f0` | None | |
3425 | | Hexagon | `reg` | None | `r0` | None | | 1527 | | Hexagon | `reg` | None | `r0` | None | |
1528 | | PowerPC | `reg` | None | `0` | None | | ||
1529 | | PowerPC | `reg_nonzero` | None | `3` | `b` | | ||
1530 | | PowerPC | `freg` | None | `0` | None | | ||
3426 | 1531 | ||
3427 | > Notes: | 1532 | > Notes: |
3428 | > - on ARM `e` / `f`: this prints the low or high doubleword register name of a NEON quad (128-bit) register. | 1533 | > - on ARM `e` / `f`: this prints the low or high doubleword register name of a NEON quad (128-bit) register. |
@@ -3503,116 +1608,633 @@ The compiler performs some additional checks on options: | |||
3503 | - You are responsible for switching any target-specific state (e.g. thread-local storage, stack bounds). | 1608 | - You are responsible for switching any target-specific state (e.g. thread-local storage, stack bounds). |
3504 | - The set of memory locations that you may access is the intersection of those allowed by the `asm!` blocks you entered and exited. | 1609 | - The set of memory locations that you may access is the intersection of those allowed by the `asm!` blocks you entered and exited. |
3505 | - You cannot assume that an `asm!` block will appear exactly once in the output binary. The compiler is allowed to instantiate multiple copies of the `asm!` block, for example when the function containing it is inlined in multiple places. | 1610 | - You cannot assume that an `asm!` block will appear exactly once in the output binary. The compiler is allowed to instantiate multiple copies of the `asm!` block, for example when the function containing it is inlined in multiple places. |
3506 | - As a consequence, you should only use [local labels] inside inline assembly code. Defining symbols in assembly code may lead to assembler and/or linker errors due to duplicate symbol definitions. | ||
3507 | 1611 | ||
3508 | > **Note**: As a general rule, the flags covered by `preserves_flags` are those which are *not* preserved when performing a function call. | 1612 | > **Note**: As a general rule, the flags covered by `preserves_flags` are those which are *not* preserved when performing a function call. |
1613 | "##, | ||
1614 | }, | ||
1615 | Lint { | ||
1616 | label: "auto_traits", | ||
1617 | description: r##"# `auto_traits` | ||
3509 | 1618 | ||
3510 | [local labels]: https://sourceware.org/binutils/docs/as/Symbol-Names.html#Local-Labels | 1619 | The tracking issue for this feature is [#13231] |
1620 | |||
1621 | [#13231]: https://github.com/rust-lang/rust/issues/13231 | ||
1622 | |||
1623 | ---- | ||
1624 | |||
1625 | The `auto_traits` feature gate allows you to define auto traits. | ||
1626 | |||
1627 | Auto traits, like [`Send`] or [`Sync`] in the standard library, are marker traits | ||
1628 | that are automatically implemented for every type, unless the type, or a type it contains, | ||
1629 | has explicitly opted out via a negative impl. (Negative impls are separately controlled | ||
1630 | by the `negative_impls` feature.) | ||
1631 | |||
1632 | [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html | ||
1633 | [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html | ||
1634 | |||
1635 | ```rust,ignore (partial-example) | ||
1636 | impl !Trait for Type {} | ||
1637 | ``` | ||
1638 | |||
1639 | Example: | ||
1640 | |||
1641 | ```rust | ||
1642 | #![feature(negative_impls)] | ||
1643 | #![feature(auto_traits)] | ||
1644 | |||
1645 | auto trait Valid {} | ||
1646 | |||
1647 | struct True; | ||
1648 | struct False; | ||
1649 | |||
1650 | impl !Valid for False {} | ||
1651 | |||
1652 | struct MaybeValid<T>(T); | ||
1653 | |||
1654 | fn must_be_valid<T: Valid>(_t: T) { } | ||
1655 | |||
1656 | fn main() { | ||
1657 | // works | ||
1658 | must_be_valid( MaybeValid(True) ); | ||
1659 | |||
1660 | // compiler error - trait bound not satisfied | ||
1661 | // must_be_valid( MaybeValid(False) ); | ||
1662 | } | ||
1663 | ``` | ||
1664 | |||
1665 | ## Automatic trait implementations | ||
1666 | |||
1667 | When a type is declared as an `auto trait`, we will automatically | ||
1668 | create impls for every struct/enum/union, unless an explicit impl is | ||
1669 | provided. These automatic impls contain a where clause for each field | ||
1670 | of the form `T: AutoTrait`, where `T` is the type of the field and | ||
1671 | `AutoTrait` is the auto trait in question. As an example, consider the | ||
1672 | struct `List` and the auto trait `Send`: | ||
1673 | |||
1674 | ```rust | ||
1675 | struct List<T> { | ||
1676 | data: T, | ||
1677 | next: Option<Box<List<T>>>, | ||
1678 | } | ||
1679 | ``` | ||
1680 | |||
1681 | Presuming that there is no explicit impl of `Send` for `List`, the | ||
1682 | compiler will supply an automatic impl of the form: | ||
1683 | |||
1684 | ```rust | ||
1685 | struct List<T> { | ||
1686 | data: T, | ||
1687 | next: Option<Box<List<T>>>, | ||
1688 | } | ||
1689 | |||
1690 | unsafe impl<T> Send for List<T> | ||
1691 | where | ||
1692 | T: Send, // from the field `data` | ||
1693 | Option<Box<List<T>>>: Send, // from the field `next` | ||
1694 | { } | ||
1695 | ``` | ||
1696 | |||
1697 | Explicit impls may be either positive or negative. They take the form: | ||
1698 | |||
1699 | ```rust,ignore (partial-example) | ||
1700 | impl<...> AutoTrait for StructName<..> { } | ||
1701 | impl<...> !AutoTrait for StructName<..> { } | ||
1702 | ``` | ||
1703 | |||
1704 | ## Coinduction: Auto traits permit cyclic matching | ||
1705 | |||
1706 | Unlike ordinary trait matching, auto traits are **coinductive**. This | ||
1707 | means, in short, that cycles which occur in trait matching are | ||
1708 | considered ok. As an example, consider the recursive struct `List` | ||
1709 | introduced in the previous section. In attempting to determine whether | ||
1710 | `List: Send`, we would wind up in a cycle: to apply the impl, we must | ||
1711 | show that `Option<Box<List>>: Send`, which will in turn require | ||
1712 | `Box<List>: Send` and then finally `List: Send` again. Under ordinary | ||
1713 | trait matching, this cycle would be an error, but for an auto trait it | ||
1714 | is considered a successful match. | ||
1715 | |||
1716 | ## Items | ||
1717 | |||
1718 | Auto traits cannot have any trait items, such as methods or associated types. This ensures that we can generate default implementations. | ||
1719 | |||
1720 | ## Supertraits | ||
1721 | |||
1722 | Auto traits cannot have supertraits. This is for soundness reasons, as the interaction of coinduction with implied bounds is difficult to reconcile. | ||
3511 | "##, | 1723 | "##, |
3512 | }, | 1724 | }, |
3513 | LintCompletion { | 1725 | Lint { |
3514 | label: "flt2dec", | 1726 | label: "box_patterns", |
3515 | description: r##"# `flt2dec` | 1727 | description: r##"# `box_patterns` |
1728 | |||
1729 | The tracking issue for this feature is: [#29641] | ||
1730 | |||
1731 | [#29641]: https://github.com/rust-lang/rust/issues/29641 | ||
1732 | |||
1733 | See also [`box_syntax`](box-syntax.md) | ||
1734 | |||
1735 | ------------------------ | ||
1736 | |||
1737 | Box patterns let you match on `Box<T>`s: | ||
1738 | |||
1739 | |||
1740 | ```rust | ||
1741 | #![feature(box_patterns)] | ||
1742 | |||
1743 | fn main() { | ||
1744 | let b = Some(Box::new(5)); | ||
1745 | match b { | ||
1746 | Some(box n) if n < 0 => { | ||
1747 | println!("Box contains negative number {}", n); | ||
1748 | }, | ||
1749 | Some(box n) if n >= 0 => { | ||
1750 | println!("Box contains non-negative number {}", n); | ||
1751 | }, | ||
1752 | None => { | ||
1753 | println!("No box"); | ||
1754 | }, | ||
1755 | _ => unreachable!() | ||
1756 | } | ||
1757 | } | ||
1758 | ``` | ||
1759 | "##, | ||
1760 | }, | ||
1761 | Lint { | ||
1762 | label: "box_syntax", | ||
1763 | description: r##"# `box_syntax` | ||
1764 | |||
1765 | The tracking issue for this feature is: [#49733] | ||
1766 | |||
1767 | [#49733]: https://github.com/rust-lang/rust/issues/49733 | ||
1768 | |||
1769 | See also [`box_patterns`](box-patterns.md) | ||
1770 | |||
1771 | ------------------------ | ||
1772 | |||
1773 | Currently the only stable way to create a `Box` is via the `Box::new` method. | ||
1774 | Also it is not possible in stable Rust to destructure a `Box` in a match | ||
1775 | pattern. The unstable `box` keyword can be used to create a `Box`. An example | ||
1776 | usage would be: | ||
1777 | |||
1778 | ```rust | ||
1779 | #![feature(box_syntax)] | ||
1780 | |||
1781 | fn main() { | ||
1782 | let b = box 5; | ||
1783 | } | ||
1784 | ``` | ||
1785 | "##, | ||
1786 | }, | ||
1787 | Lint { | ||
1788 | label: "c_unwind", | ||
1789 | description: r##"# `c_unwind` | ||
1790 | |||
1791 | The tracking issue for this feature is: [#74990] | ||
1792 | |||
1793 | [#74990]: https://github.com/rust-lang/rust/issues/74990 | ||
1794 | |||
1795 | ------------------------ | ||
1796 | |||
1797 | Introduces four new ABI strings: "C-unwind", "stdcall-unwind", | ||
1798 | "thiscall-unwind", and "system-unwind". These enable unwinding from other | ||
1799 | languages (such as C++) into Rust frames and from Rust into other languages. | ||
1800 | |||
1801 | See [RFC 2945] for more information. | ||
1802 | |||
1803 | [RFC 2945]: https://github.com/rust-lang/rfcs/blob/master/text/2945-c-unwind-abi.md | ||
1804 | "##, | ||
1805 | }, | ||
1806 | Lint { | ||
1807 | label: "c_variadic", | ||
1808 | description: r##"# `c_variadic` | ||
1809 | |||
1810 | The tracking issue for this feature is: [#44930] | ||
1811 | |||
1812 | [#44930]: https://github.com/rust-lang/rust/issues/44930 | ||
1813 | |||
1814 | ------------------------ | ||
1815 | |||
1816 | The `c_variadic` language feature enables C-variadic functions to be | ||
1817 | defined in Rust. The may be called both from within Rust and via FFI. | ||
1818 | |||
1819 | ## Examples | ||
1820 | |||
1821 | ```rust | ||
1822 | #![feature(c_variadic)] | ||
1823 | |||
1824 | pub unsafe extern "C" fn add(n: usize, mut args: ...) -> usize { | ||
1825 | let mut sum = 0; | ||
1826 | for _ in 0..n { | ||
1827 | sum += args.arg::<usize>(); | ||
1828 | } | ||
1829 | sum | ||
1830 | } | ||
1831 | ``` | ||
1832 | "##, | ||
1833 | }, | ||
1834 | Lint { | ||
1835 | label: "c_variadic", | ||
1836 | description: r##"# `c_variadic` | ||
1837 | |||
1838 | The tracking issue for this feature is: [#44930] | ||
1839 | |||
1840 | [#44930]: https://github.com/rust-lang/rust/issues/44930 | ||
1841 | |||
1842 | ------------------------ | ||
1843 | |||
1844 | The `c_variadic` library feature exposes the `VaList` structure, | ||
1845 | Rust's analogue of C's `va_list` type. | ||
1846 | |||
1847 | ## Examples | ||
1848 | |||
1849 | ```rust | ||
1850 | #![feature(c_variadic)] | ||
1851 | |||
1852 | use std::ffi::VaList; | ||
1853 | |||
1854 | pub unsafe extern "C" fn vadd(n: usize, mut args: VaList) -> usize { | ||
1855 | let mut sum = 0; | ||
1856 | for _ in 0..n { | ||
1857 | sum += args.arg::<usize>(); | ||
1858 | } | ||
1859 | sum | ||
1860 | } | ||
1861 | ``` | ||
1862 | "##, | ||
1863 | }, | ||
1864 | Lint { | ||
1865 | label: "c_void_variant", | ||
1866 | description: r##"# `c_void_variant` | ||
3516 | 1867 | ||
3517 | This feature is internal to the Rust compiler and is not intended for general use. | 1868 | This feature is internal to the Rust compiler and is not intended for general use. |
3518 | 1869 | ||
3519 | ------------------------ | 1870 | ------------------------ |
3520 | "##, | 1871 | "##, |
3521 | }, | 1872 | }, |
3522 | LintCompletion { | 1873 | Lint { |
3523 | label: "global_asm", | 1874 | label: "cfg_panic", |
3524 | description: r##"# `global_asm` | 1875 | description: r##"# `cfg_panic` |
3525 | 1876 | ||
3526 | The tracking issue for this feature is: [#35119] | 1877 | The tracking issue for this feature is: [#77443] |
3527 | 1878 | ||
3528 | [#35119]: https://github.com/rust-lang/rust/issues/35119 | 1879 | [#77443]: https://github.com/rust-lang/rust/issues/77443 |
3529 | 1880 | ||
3530 | ------------------------ | 1881 | ------------------------ |
3531 | 1882 | ||
3532 | The `global_asm!` macro allows the programmer to write arbitrary | 1883 | The `cfg_panic` feature makes it possible to execute different code |
3533 | assembly outside the scope of a function body, passing it through | 1884 | depending on the panic strategy. |
3534 | `rustc` and `llvm` to the assembler. The macro is a no-frills | ||
3535 | interface to LLVM's concept of [module-level inline assembly]. That is, | ||
3536 | all caveats applicable to LLVM's module-level inline assembly apply | ||
3537 | to `global_asm!`. | ||
3538 | 1885 | ||
3539 | [module-level inline assembly]: http://llvm.org/docs/LangRef.html#module-level-inline-assembly | 1886 | Possible values at the moment are `"unwind"` or `"abort"`, although |
1887 | it is possible that new panic strategies may be added to Rust in the | ||
1888 | future. | ||
3540 | 1889 | ||
3541 | `global_asm!` fills a role not currently satisfied by either `asm!` | 1890 | ## Examples |
3542 | or `#[naked]` functions. The programmer has _all_ features of the | ||
3543 | assembler at their disposal. The linker will expect to resolve any | ||
3544 | symbols defined in the inline assembly, modulo any symbols marked as | ||
3545 | external. It also means syntax for directives and assembly follow the | ||
3546 | conventions of the assembler in your toolchain. | ||
3547 | 1891 | ||
3548 | A simple usage looks like this: | 1892 | ```rust |
1893 | #![feature(cfg_panic)] | ||
3549 | 1894 | ||
3550 | ```rust,ignore (requires-external-file) | 1895 | #[cfg(panic = "unwind")] |
3551 | #![feature(global_asm)] | 1896 | fn a() { |
3552 | # // you also need relevant target_arch cfgs | 1897 | // ... |
3553 | global_asm!(include_str!("something_neato.s")); | 1898 | } |
1899 | |||
1900 | #[cfg(not(panic = "unwind"))] | ||
1901 | fn a() { | ||
1902 | // ... | ||
1903 | } | ||
1904 | |||
1905 | fn b() { | ||
1906 | if cfg!(panic = "abort") { | ||
1907 | // ... | ||
1908 | } else { | ||
1909 | // ... | ||
1910 | } | ||
1911 | } | ||
3554 | ``` | 1912 | ``` |
1913 | "##, | ||
1914 | }, | ||
1915 | Lint { | ||
1916 | label: "cfg_sanitize", | ||
1917 | description: r##"# `cfg_sanitize` | ||
3555 | 1918 | ||
3556 | And a more complicated usage looks like this: | 1919 | The tracking issue for this feature is: [#39699] |
3557 | 1920 | ||
3558 | ```rust,no_run | 1921 | [#39699]: https://github.com/rust-lang/rust/issues/39699 |
3559 | #![feature(global_asm)] | ||
3560 | # #[cfg(any(target_arch="x86", target_arch="x86_64"))] | ||
3561 | # mod x86 { | ||
3562 | 1922 | ||
3563 | pub mod sally { | 1923 | ------------------------ |
3564 | global_asm!(r#" | ||
3565 | .global foo | ||
3566 | foo: | ||
3567 | jmp baz | ||
3568 | "#); | ||
3569 | 1924 | ||
3570 | #[no_mangle] | 1925 | The `cfg_sanitize` feature makes it possible to execute different code |
3571 | pub unsafe extern "C" fn baz() {} | 1926 | depending on whether a particular sanitizer is enabled or not. |
1927 | |||
1928 | ## Examples | ||
1929 | |||
1930 | ```rust | ||
1931 | #![feature(cfg_sanitize)] | ||
1932 | |||
1933 | #[cfg(sanitize = "thread")] | ||
1934 | fn a() { | ||
1935 | // ... | ||
3572 | } | 1936 | } |
3573 | 1937 | ||
3574 | // the symbols `foo` and `bar` are global, no matter where | 1938 | #[cfg(not(sanitize = "thread"))] |
3575 | // `global_asm!` was used. | 1939 | fn a() { |
3576 | extern "C" { | 1940 | // ... |
3577 | fn foo(); | ||
3578 | fn bar(); | ||
3579 | } | 1941 | } |
3580 | 1942 | ||
3581 | pub mod harry { | 1943 | fn b() { |
3582 | global_asm!(r#" | 1944 | if cfg!(sanitize = "leak") { |
3583 | .global bar | 1945 | // ... |
3584 | bar: | 1946 | } else { |
3585 | jmp quux | 1947 | // ... |
3586 | "#); | 1948 | } |
1949 | } | ||
1950 | ``` | ||
1951 | "##, | ||
1952 | }, | ||
1953 | Lint { | ||
1954 | label: "cfg_version", | ||
1955 | description: r##"# `cfg_version` | ||
3587 | 1956 | ||
3588 | #[no_mangle] | 1957 | The tracking issue for this feature is: [#64796] |
3589 | pub unsafe extern "C" fn quux() {} | 1958 | |
1959 | [#64796]: https://github.com/rust-lang/rust/issues/64796 | ||
1960 | |||
1961 | ------------------------ | ||
1962 | |||
1963 | The `cfg_version` feature makes it possible to execute different code | ||
1964 | depending on the compiler version. It will return true if the compiler | ||
1965 | version is greater than or equal to the specified version. | ||
1966 | |||
1967 | ## Examples | ||
1968 | |||
1969 | ```rust | ||
1970 | #![feature(cfg_version)] | ||
1971 | |||
1972 | #[cfg(version("1.42"))] // 1.42 and above | ||
1973 | fn a() { | ||
1974 | // ... | ||
1975 | } | ||
1976 | |||
1977 | #[cfg(not(version("1.42")))] // 1.41 and below | ||
1978 | fn a() { | ||
1979 | // ... | ||
1980 | } | ||
1981 | |||
1982 | fn b() { | ||
1983 | if cfg!(version("1.42")) { | ||
1984 | // ... | ||
1985 | } else { | ||
1986 | // ... | ||
1987 | } | ||
3590 | } | 1988 | } |
3591 | # } | ||
3592 | ``` | 1989 | ``` |
1990 | "##, | ||
1991 | }, | ||
1992 | Lint { | ||
1993 | label: "char_error_internals", | ||
1994 | description: r##"# `char_error_internals` | ||
3593 | 1995 | ||
3594 | You may use `global_asm!` multiple times, anywhere in your crate, in | 1996 | This feature is internal to the Rust compiler and is not intended for general use. |
3595 | whatever way suits you. The effect is as if you concatenated all | ||
3596 | usages and placed the larger, single usage in the crate root. | ||
3597 | 1997 | ||
3598 | ------------------------ | 1998 | ------------------------ |
1999 | "##, | ||
2000 | }, | ||
2001 | Lint { | ||
2002 | label: "cmse_nonsecure_entry", | ||
2003 | description: r##"# `cmse_nonsecure_entry` | ||
3599 | 2004 | ||
3600 | If you don't need quite as much power and flexibility as | 2005 | The tracking issue for this feature is: [#75835] |
3601 | `global_asm!` provides, and you don't mind restricting your inline | 2006 | |
3602 | assembly to `fn` bodies only, you might try the | 2007 | [#75835]: https://github.com/rust-lang/rust/issues/75835 |
3603 | [asm](asm.md) feature instead. | 2008 | |
2009 | ------------------------ | ||
2010 | |||
2011 | The [TrustZone-M | ||
2012 | feature](https://developer.arm.com/documentation/100690/latest/) is available | ||
2013 | for targets with the Armv8-M architecture profile (`thumbv8m` in their target | ||
2014 | name). | ||
2015 | LLVM, the Rust compiler and the linker are providing | ||
2016 | [support](https://developer.arm.com/documentation/ecm0359818/latest/) for the | ||
2017 | TrustZone-M feature. | ||
2018 | |||
2019 | One of the things provided, with this unstable feature, is the | ||
2020 | `cmse_nonsecure_entry` attribute. This attribute marks a Secure function as an | ||
2021 | entry function (see [section | ||
2022 | 5.4](https://developer.arm.com/documentation/ecm0359818/latest/) for details). | ||
2023 | With this attribute, the compiler will do the following: | ||
2024 | * add a special symbol on the function which is the `__acle_se_` prefix and the | ||
2025 | standard function name | ||
2026 | * constrain the number of parameters to avoid using the Non-Secure stack | ||
2027 | * before returning from the function, clear registers that might contain Secure | ||
2028 | information | ||
2029 | * use the `BXNS` instruction to return | ||
2030 | |||
2031 | Because the stack can not be used to pass parameters, there will be compilation | ||
2032 | errors if: | ||
2033 | * the total size of all parameters is too big (for example more than four 32 | ||
2034 | bits integers) | ||
2035 | * the entry function is not using a C ABI | ||
2036 | |||
2037 | The special symbol `__acle_se_` will be used by the linker to generate a secure | ||
2038 | gateway veneer. | ||
2039 | |||
2040 | <!-- NOTE(ignore) this example is specific to thumbv8m targets --> | ||
2041 | |||
2042 | ``` rust,ignore | ||
2043 | #![feature(cmse_nonsecure_entry)] | ||
2044 | |||
2045 | #[no_mangle] | ||
2046 | #[cmse_nonsecure_entry] | ||
2047 | pub extern "C" fn entry_function(input: u32) -> u32 { | ||
2048 | input + 6 | ||
2049 | } | ||
2050 | ``` | ||
2051 | |||
2052 | ``` text | ||
2053 | $ rustc --emit obj --crate-type lib --target thumbv8m.main-none-eabi function.rs | ||
2054 | $ arm-none-eabi-objdump -D function.o | ||
2055 | |||
2056 | 00000000 <entry_function>: | ||
2057 | 0: b580 push {r7, lr} | ||
2058 | 2: 466f mov r7, sp | ||
2059 | 4: b082 sub sp, #8 | ||
2060 | 6: 9001 str r0, [sp, #4] | ||
2061 | 8: 1d81 adds r1, r0, #6 | ||
2062 | a: 460a mov r2, r1 | ||
2063 | c: 4281 cmp r1, r0 | ||
2064 | e: 9200 str r2, [sp, #0] | ||
2065 | 10: d30b bcc.n 2a <entry_function+0x2a> | ||
2066 | 12: e7ff b.n 14 <entry_function+0x14> | ||
2067 | 14: 9800 ldr r0, [sp, #0] | ||
2068 | 16: b002 add sp, #8 | ||
2069 | 18: e8bd 4080 ldmia.w sp!, {r7, lr} | ||
2070 | 1c: 4671 mov r1, lr | ||
2071 | 1e: 4672 mov r2, lr | ||
2072 | 20: 4673 mov r3, lr | ||
2073 | 22: 46f4 mov ip, lr | ||
2074 | 24: f38e 8800 msr CPSR_f, lr | ||
2075 | 28: 4774 bxns lr | ||
2076 | 2a: f240 0000 movw r0, #0 | ||
2077 | 2e: f2c0 0000 movt r0, #0 | ||
2078 | 32: f240 0200 movw r2, #0 | ||
2079 | 36: f2c0 0200 movt r2, #0 | ||
2080 | 3a: 211c movs r1, #28 | ||
2081 | 3c: f7ff fffe bl 0 <_ZN4core9panicking5panic17h5c028258ca2fb3f5E> | ||
2082 | 40: defe udf #254 ; 0xfe | ||
2083 | ``` | ||
3604 | "##, | 2084 | "##, |
3605 | }, | 2085 | }, |
3606 | LintCompletion { | 2086 | Lint { |
3607 | label: "derive_eq", | 2087 | label: "compiler_builtins", |
3608 | description: r##"# `derive_eq` | 2088 | description: r##"# `compiler_builtins` |
3609 | 2089 | ||
3610 | This feature is internal to the Rust compiler and is not intended for general use. | 2090 | This feature is internal to the Rust compiler and is not intended for general use. |
3611 | 2091 | ||
3612 | ------------------------ | 2092 | ------------------------ |
3613 | "##, | 2093 | "##, |
3614 | }, | 2094 | }, |
3615 | LintCompletion { | 2095 | Lint { |
2096 | label: "concat_idents", | ||
2097 | description: r##"# `concat_idents` | ||
2098 | |||
2099 | The tracking issue for this feature is: [#29599] | ||
2100 | |||
2101 | [#29599]: https://github.com/rust-lang/rust/issues/29599 | ||
2102 | |||
2103 | ------------------------ | ||
2104 | |||
2105 | The `concat_idents` feature adds a macro for concatenating multiple identifiers | ||
2106 | into one identifier. | ||
2107 | |||
2108 | ## Examples | ||
2109 | |||
2110 | ```rust | ||
2111 | #![feature(concat_idents)] | ||
2112 | |||
2113 | fn main() { | ||
2114 | fn foobar() -> u32 { 23 } | ||
2115 | let f = concat_idents!(foo, bar); | ||
2116 | assert_eq!(f(), 23); | ||
2117 | } | ||
2118 | ``` | ||
2119 | "##, | ||
2120 | }, | ||
2121 | Lint { | ||
2122 | label: "const_eval_limit", | ||
2123 | description: r##"# `const_eval_limit` | ||
2124 | |||
2125 | The tracking issue for this feature is: [#67217] | ||
2126 | |||
2127 | [#67217]: https://github.com/rust-lang/rust/issues/67217 | ||
2128 | |||
2129 | The `const_eval_limit` allows someone to limit the evaluation steps the CTFE undertakes to evaluate a `const fn`. | ||
2130 | "##, | ||
2131 | }, | ||
2132 | Lint { | ||
2133 | label: "core_intrinsics", | ||
2134 | description: r##"# `core_intrinsics` | ||
2135 | |||
2136 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2137 | |||
2138 | ------------------------ | ||
2139 | "##, | ||
2140 | }, | ||
2141 | Lint { | ||
2142 | label: "core_panic", | ||
2143 | description: r##"# `core_panic` | ||
2144 | |||
2145 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2146 | |||
2147 | ------------------------ | ||
2148 | "##, | ||
2149 | }, | ||
2150 | Lint { | ||
2151 | label: "core_private_bignum", | ||
2152 | description: r##"# `core_private_bignum` | ||
2153 | |||
2154 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2155 | |||
2156 | ------------------------ | ||
2157 | "##, | ||
2158 | }, | ||
2159 | Lint { | ||
2160 | label: "core_private_diy_float", | ||
2161 | description: r##"# `core_private_diy_float` | ||
2162 | |||
2163 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2164 | |||
2165 | ------------------------ | ||
2166 | "##, | ||
2167 | }, | ||
2168 | Lint { | ||
2169 | label: "crate_visibility_modifier", | ||
2170 | description: r##"# `crate_visibility_modifier` | ||
2171 | |||
2172 | The tracking issue for this feature is: [#53120] | ||
2173 | |||
2174 | [#53120]: https://github.com/rust-lang/rust/issues/53120 | ||
2175 | |||
2176 | ----- | ||
2177 | |||
2178 | The `crate_visibility_modifier` feature allows the `crate` keyword to be used | ||
2179 | as a visibility modifier synonymous to `pub(crate)`, indicating that a type | ||
2180 | (function, _&c._) is to be visible to the entire enclosing crate, but not to | ||
2181 | other crates. | ||
2182 | |||
2183 | ```rust | ||
2184 | #![feature(crate_visibility_modifier)] | ||
2185 | |||
2186 | crate struct Foo { | ||
2187 | bar: usize, | ||
2188 | } | ||
2189 | ``` | ||
2190 | "##, | ||
2191 | }, | ||
2192 | Lint { | ||
2193 | label: "custom_test_frameworks", | ||
2194 | description: r##"# `custom_test_frameworks` | ||
2195 | |||
2196 | The tracking issue for this feature is: [#50297] | ||
2197 | |||
2198 | [#50297]: https://github.com/rust-lang/rust/issues/50297 | ||
2199 | |||
2200 | ------------------------ | ||
2201 | |||
2202 | The `custom_test_frameworks` feature allows the use of `#[test_case]` and `#![test_runner]`. | ||
2203 | Any function, const, or static can be annotated with `#[test_case]` causing it to be aggregated (like `#[test]`) | ||
2204 | and be passed to the test runner determined by the `#![test_runner]` crate attribute. | ||
2205 | |||
2206 | ```rust | ||
2207 | #![feature(custom_test_frameworks)] | ||
2208 | #![test_runner(my_runner)] | ||
2209 | |||
2210 | fn my_runner(tests: &[&i32]) { | ||
2211 | for t in tests { | ||
2212 | if **t == 0 { | ||
2213 | println!("PASSED"); | ||
2214 | } else { | ||
2215 | println!("FAILED"); | ||
2216 | } | ||
2217 | } | ||
2218 | } | ||
2219 | |||
2220 | #[test_case] | ||
2221 | const WILL_PASS: i32 = 0; | ||
2222 | |||
2223 | #[test_case] | ||
2224 | const WILL_FAIL: i32 = 4; | ||
2225 | ``` | ||
2226 | "##, | ||
2227 | }, | ||
2228 | Lint { | ||
2229 | label: "dec2flt", | ||
2230 | description: r##"# `dec2flt` | ||
2231 | |||
2232 | This feature is internal to the Rust compiler and is not intended for general use. | ||
2233 | |||
2234 | ------------------------ | ||
2235 | "##, | ||
2236 | }, | ||
2237 | Lint { | ||
3616 | label: "default_free_fn", | 2238 | label: "default_free_fn", |
3617 | description: r##"# `default_free_fn` | 2239 | description: r##"# `default_free_fn` |
3618 | 2240 | ||
@@ -3663,75 +2285,375 @@ fn main() { | |||
3663 | ``` | 2285 | ``` |
3664 | "##, | 2286 | "##, |
3665 | }, | 2287 | }, |
3666 | LintCompletion { | 2288 | Lint { |
3667 | label: "char_error_internals", | 2289 | label: "derive_clone_copy", |
3668 | description: r##"# `char_error_internals` | 2290 | description: r##"# `derive_clone_copy` |
3669 | 2291 | ||
3670 | This feature is internal to the Rust compiler and is not intended for general use. | 2292 | This feature is internal to the Rust compiler and is not intended for general use. |
3671 | 2293 | ||
3672 | ------------------------ | 2294 | ------------------------ |
3673 | "##, | 2295 | "##, |
3674 | }, | 2296 | }, |
3675 | LintCompletion { | 2297 | Lint { |
3676 | label: "libstd_sys_internals", | 2298 | label: "derive_eq", |
3677 | description: r##"# `libstd_sys_internals` | 2299 | description: r##"# `derive_eq` |
3678 | 2300 | ||
3679 | This feature is internal to the Rust compiler and is not intended for general use. | 2301 | This feature is internal to the Rust compiler and is not intended for general use. |
3680 | 2302 | ||
3681 | ------------------------ | 2303 | ------------------------ |
3682 | "##, | 2304 | "##, |
3683 | }, | 2305 | }, |
3684 | LintCompletion { | 2306 | Lint { |
3685 | label: "is_sorted", | 2307 | label: "doc_cfg", |
3686 | description: r##"# `is_sorted` | 2308 | description: r##"# `doc_cfg` |
3687 | 2309 | ||
3688 | The tracking issue for this feature is: [#53485] | 2310 | The tracking issue for this feature is: [#43781] |
3689 | 2311 | ||
3690 | [#53485]: https://github.com/rust-lang/rust/issues/53485 | 2312 | ------ |
3691 | 2313 | ||
3692 | ------------------------ | 2314 | The `doc_cfg` feature allows an API be documented as only available in some specific platforms. |
2315 | This attribute has two effects: | ||
3693 | 2316 | ||
3694 | Add the methods `is_sorted`, `is_sorted_by` and `is_sorted_by_key` to `[T]`; | 2317 | 1. In the annotated item's documentation, there will be a message saying "This is supported on |
3695 | add the methods `is_sorted`, `is_sorted_by` and `is_sorted_by_key` to | 2318 | (platform) only". |
3696 | `Iterator`. | 2319 | |
2320 | 2. The item's doc-tests will only run on the specific platform. | ||
2321 | |||
2322 | In addition to allowing the use of the `#[doc(cfg)]` attribute, this feature enables the use of a | ||
2323 | special conditional compilation flag, `#[cfg(doc)]`, set whenever building documentation on your | ||
2324 | crate. | ||
2325 | |||
2326 | This feature was introduced as part of PR [#43348] to allow the platform-specific parts of the | ||
2327 | standard library be documented. | ||
2328 | |||
2329 | ```rust | ||
2330 | #![feature(doc_cfg)] | ||
2331 | |||
2332 | #[cfg(any(windows, doc))] | ||
2333 | #[doc(cfg(windows))] | ||
2334 | /// The application's icon in the notification area (a.k.a. system tray). | ||
2335 | /// | ||
2336 | /// # Examples | ||
2337 | /// | ||
2338 | /// ```no_run | ||
2339 | /// extern crate my_awesome_ui_library; | ||
2340 | /// use my_awesome_ui_library::current_app; | ||
2341 | /// use my_awesome_ui_library::windows::notification; | ||
2342 | /// | ||
2343 | /// let icon = current_app().get::<notification::Icon>(); | ||
2344 | /// icon.show(); | ||
2345 | /// icon.show_message("Hello"); | ||
2346 | /// ``` | ||
2347 | pub struct Icon { | ||
2348 | // ... | ||
2349 | } | ||
2350 | ``` | ||
2351 | |||
2352 | [#43781]: https://github.com/rust-lang/rust/issues/43781 | ||
2353 | [#43348]: https://github.com/rust-lang/rust/issues/43348 | ||
3697 | "##, | 2354 | "##, |
3698 | }, | 2355 | }, |
3699 | LintCompletion { | 2356 | Lint { |
3700 | label: "c_void_variant", | 2357 | label: "doc_masked", |
3701 | description: r##"# `c_void_variant` | 2358 | description: r##"# `doc_masked` |
2359 | |||
2360 | The tracking issue for this feature is: [#44027] | ||
2361 | |||
2362 | ----- | ||
2363 | |||
2364 | The `doc_masked` feature allows a crate to exclude types from a given crate from appearing in lists | ||
2365 | of trait implementations. The specifics of the feature are as follows: | ||
2366 | |||
2367 | 1. When rustdoc encounters an `extern crate` statement annotated with a `#[doc(masked)]` attribute, | ||
2368 | it marks the crate as being masked. | ||
2369 | |||
2370 | 2. When listing traits a given type implements, rustdoc ensures that traits from masked crates are | ||
2371 | not emitted into the documentation. | ||
2372 | |||
2373 | 3. When listing types that implement a given trait, rustdoc ensures that types from masked crates | ||
2374 | are not emitted into the documentation. | ||
2375 | |||
2376 | This feature was introduced in PR [#44026] to ensure that compiler-internal and | ||
2377 | implementation-specific types and traits were not included in the standard library's documentation. | ||
2378 | Such types would introduce broken links into the documentation. | ||
2379 | |||
2380 | [#44026]: https://github.com/rust-lang/rust/pull/44026 | ||
2381 | [#44027]: https://github.com/rust-lang/rust/pull/44027 | ||
2382 | "##, | ||
2383 | }, | ||
2384 | Lint { | ||
2385 | label: "doc_notable_trait", | ||
2386 | description: r##"# `doc_notable_trait` | ||
2387 | |||
2388 | The tracking issue for this feature is: [#45040] | ||
2389 | |||
2390 | The `doc_notable_trait` feature allows the use of the `#[doc(notable_trait)]` | ||
2391 | attribute, which will display the trait in a "Notable traits" dialog for | ||
2392 | functions returning types that implement the trait. For example, this attribute | ||
2393 | is applied to the `Iterator`, `Future`, `io::Read`, and `io::Write` traits in | ||
2394 | the standard library. | ||
2395 | |||
2396 | You can do this on your own traits like so: | ||
2397 | |||
2398 | ``` | ||
2399 | #![feature(doc_notable_trait)] | ||
2400 | |||
2401 | #[doc(notable_trait)] | ||
2402 | pub trait MyTrait {} | ||
2403 | |||
2404 | pub struct MyStruct; | ||
2405 | impl MyTrait for MyStruct {} | ||
2406 | |||
2407 | /// The docs for this function will have a button that displays a dialog about | ||
2408 | /// `MyStruct` implementing `MyTrait`. | ||
2409 | pub fn my_fn() -> MyStruct { MyStruct } | ||
2410 | ``` | ||
2411 | |||
2412 | This feature was originally implemented in PR [#45039]. | ||
2413 | |||
2414 | See also its documentation in [the rustdoc book][rustdoc-book-notable_trait]. | ||
2415 | |||
2416 | [#45040]: https://github.com/rust-lang/rust/issues/45040 | ||
2417 | [#45039]: https://github.com/rust-lang/rust/pull/45039 | ||
2418 | [rustdoc-book-notable_trait]: ../../rustdoc/unstable-features.html#adding-your-trait-to-the-notable-traits-dialog | ||
2419 | "##, | ||
2420 | }, | ||
2421 | Lint { | ||
2422 | label: "external_doc", | ||
2423 | description: r##"# `external_doc` | ||
2424 | |||
2425 | The tracking issue for this feature is: [#44732] | ||
2426 | |||
2427 | The `external_doc` feature allows the use of the `include` parameter to the `#[doc]` attribute, to | ||
2428 | include external files in documentation. Use the attribute in place of, or in addition to, regular | ||
2429 | doc comments and `#[doc]` attributes, and `rustdoc` will load the given file when it renders | ||
2430 | documentation for your crate. | ||
2431 | |||
2432 | With the following files in the same directory: | ||
2433 | |||
2434 | `external-doc.md`: | ||
2435 | |||
2436 | ```markdown | ||
2437 | # My Awesome Type | ||
2438 | |||
2439 | This is the documentation for this spectacular type. | ||
2440 | ``` | ||
2441 | |||
2442 | `lib.rs`: | ||
2443 | |||
2444 | ```no_run (needs-external-files) | ||
2445 | #![feature(external_doc)] | ||
2446 | |||
2447 | #[doc(include = "external-doc.md")] | ||
2448 | pub struct MyAwesomeType; | ||
2449 | ``` | ||
2450 | |||
2451 | `rustdoc` will load the file `external-doc.md` and use it as the documentation for the `MyAwesomeType` | ||
2452 | struct. | ||
2453 | |||
2454 | When locating files, `rustdoc` will base paths in the `src/` directory, as if they were alongside the | ||
2455 | `lib.rs` for your crate. So if you want a `docs/` folder to live alongside the `src/` directory, | ||
2456 | start your paths with `../docs/` for `rustdoc` to properly find the file. | ||
2457 | |||
2458 | This feature was proposed in [RFC #1990] and initially implemented in PR [#44781]. | ||
2459 | |||
2460 | [#44732]: https://github.com/rust-lang/rust/issues/44732 | ||
2461 | [RFC #1990]: https://github.com/rust-lang/rfcs/pull/1990 | ||
2462 | [#44781]: https://github.com/rust-lang/rust/pull/44781 | ||
2463 | "##, | ||
2464 | }, | ||
2465 | Lint { | ||
2466 | label: "fd", | ||
2467 | description: r##"# `fd` | ||
3702 | 2468 | ||
3703 | This feature is internal to the Rust compiler and is not intended for general use. | 2469 | This feature is internal to the Rust compiler and is not intended for general use. |
3704 | 2470 | ||
3705 | ------------------------ | 2471 | ------------------------ |
3706 | "##, | 2472 | "##, |
3707 | }, | 2473 | }, |
3708 | LintCompletion { | 2474 | Lint { |
3709 | label: "concat_idents", | 2475 | label: "fd_read", |
3710 | description: r##"# `concat_idents` | 2476 | description: r##"# `fd_read` |
3711 | 2477 | ||
3712 | The tracking issue for this feature is: [#29599] | 2478 | This feature is internal to the Rust compiler and is not intended for general use. |
3713 | 2479 | ||
3714 | [#29599]: https://github.com/rust-lang/rust/issues/29599 | 2480 | ------------------------ |
2481 | "##, | ||
2482 | }, | ||
2483 | Lint { | ||
2484 | label: "ffi_const", | ||
2485 | description: r##"# `ffi_const` | ||
2486 | |||
2487 | The tracking issue for this feature is: [#58328] | ||
2488 | |||
2489 | ------ | ||
2490 | |||
2491 | The `#[ffi_const]` attribute applies clang's `const` attribute to foreign | ||
2492 | functions declarations. | ||
2493 | |||
2494 | That is, `#[ffi_const]` functions shall have no effects except for its return | ||
2495 | value, which can only depend on the values of the function parameters, and is | ||
2496 | not affected by changes to the observable state of the program. | ||
2497 | |||
2498 | Applying the `#[ffi_const]` attribute to a function that violates these | ||
2499 | requirements is undefined behaviour. | ||
2500 | |||
2501 | This attribute enables Rust to perform common optimizations, like sub-expression | ||
2502 | elimination, and it can avoid emitting some calls in repeated invocations of the | ||
2503 | function with the same argument values regardless of other operations being | ||
2504 | performed in between these functions calls (as opposed to `#[ffi_pure]` | ||
2505 | functions). | ||
2506 | |||
2507 | ## Pitfalls | ||
2508 | |||
2509 | A `#[ffi_const]` function can only read global memory that would not affect | ||
2510 | its return value for the whole execution of the program (e.g. immutable global | ||
2511 | memory). `#[ffi_const]` functions are referentially-transparent and therefore | ||
2512 | more strict than `#[ffi_pure]` functions. | ||
2513 | |||
2514 | A common pitfall involves applying the `#[ffi_const]` attribute to a | ||
2515 | function that reads memory through pointer arguments which do not necessarily | ||
2516 | point to immutable global memory. | ||
2517 | |||
2518 | A `#[ffi_const]` function that returns unit has no effect on the abstract | ||
2519 | machine's state, and a `#[ffi_const]` function cannot be `#[ffi_pure]`. | ||
2520 | |||
2521 | A `#[ffi_const]` function must not diverge, neither via a side effect (e.g. a | ||
2522 | call to `abort`) nor by infinite loops. | ||
2523 | |||
2524 | When translating C headers to Rust FFI, it is worth verifying for which targets | ||
2525 | the `const` attribute is enabled in those headers, and using the appropriate | ||
2526 | `cfg` macros in the Rust side to match those definitions. While the semantics of | ||
2527 | `const` are implemented identically by many C and C++ compilers, e.g., clang, | ||
2528 | [GCC], [ARM C/C++ compiler], [IBM ILE C/C++], etc. they are not necessarily | ||
2529 | implemented in this way on all of them. It is therefore also worth verifying | ||
2530 | that the semantics of the C toolchain used to compile the binary being linked | ||
2531 | against are compatible with those of the `#[ffi_const]`. | ||
2532 | |||
2533 | [#58328]: https://github.com/rust-lang/rust/issues/58328 | ||
2534 | [ARM C/C++ compiler]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0491c/Cacgigch.html | ||
2535 | [GCC]: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-const-function-attribute | ||
2536 | [IBM ILE C/C++]: https://www.ibm.com/support/knowledgecenter/fr/ssw_ibm_i_71/rzarg/fn_attrib_const.htm | ||
2537 | "##, | ||
2538 | }, | ||
2539 | Lint { | ||
2540 | label: "ffi_pure", | ||
2541 | description: r##"# `ffi_pure` | ||
2542 | |||
2543 | The tracking issue for this feature is: [#58329] | ||
2544 | |||
2545 | ------ | ||
2546 | |||
2547 | The `#[ffi_pure]` attribute applies clang's `pure` attribute to foreign | ||
2548 | functions declarations. | ||
2549 | |||
2550 | That is, `#[ffi_pure]` functions shall have no effects except for its return | ||
2551 | value, which shall not change across two consecutive function calls with | ||
2552 | the same parameters. | ||
2553 | |||
2554 | Applying the `#[ffi_pure]` attribute to a function that violates these | ||
2555 | requirements is undefined behavior. | ||
2556 | |||
2557 | This attribute enables Rust to perform common optimizations, like sub-expression | ||
2558 | elimination and loop optimizations. Some common examples of pure functions are | ||
2559 | `strlen` or `memcmp`. | ||
2560 | |||
2561 | These optimizations are only applicable when the compiler can prove that no | ||
2562 | program state observable by the `#[ffi_pure]` function has changed between calls | ||
2563 | of the function, which could alter the result. See also the `#[ffi_const]` | ||
2564 | attribute, which provides stronger guarantees regarding the allowable behavior | ||
2565 | of a function, enabling further optimization. | ||
2566 | |||
2567 | ## Pitfalls | ||
2568 | |||
2569 | A `#[ffi_pure]` function can read global memory through the function | ||
2570 | parameters (e.g. pointers), globals, etc. `#[ffi_pure]` functions are not | ||
2571 | referentially-transparent, and are therefore more relaxed than `#[ffi_const]` | ||
2572 | functions. | ||
2573 | |||
2574 | However, accessing global memory through volatile or atomic reads can violate the | ||
2575 | requirement that two consecutive function calls shall return the same value. | ||
2576 | |||
2577 | A `pure` function that returns unit has no effect on the abstract machine's | ||
2578 | state. | ||
2579 | |||
2580 | A `#[ffi_pure]` function must not diverge, neither via a side effect (e.g. a | ||
2581 | call to `abort`) nor by infinite loops. | ||
2582 | |||
2583 | When translating C headers to Rust FFI, it is worth verifying for which targets | ||
2584 | the `pure` attribute is enabled in those headers, and using the appropriate | ||
2585 | `cfg` macros in the Rust side to match those definitions. While the semantics of | ||
2586 | `pure` are implemented identically by many C and C++ compilers, e.g., clang, | ||
2587 | [GCC], [ARM C/C++ compiler], [IBM ILE C/C++], etc. they are not necessarily | ||
2588 | implemented in this way on all of them. It is therefore also worth verifying | ||
2589 | that the semantics of the C toolchain used to compile the binary being linked | ||
2590 | against are compatible with those of the `#[ffi_pure]`. | ||
2591 | |||
2592 | |||
2593 | [#58329]: https://github.com/rust-lang/rust/issues/58329 | ||
2594 | [ARM C/C++ compiler]: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0491c/Cacigdac.html | ||
2595 | [GCC]: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-pure-function-attribute | ||
2596 | [IBM ILE C/C++]: https://www.ibm.com/support/knowledgecenter/fr/ssw_ibm_i_71/rzarg/fn_attrib_pure.htm | ||
2597 | "##, | ||
2598 | }, | ||
2599 | Lint { | ||
2600 | label: "flt2dec", | ||
2601 | description: r##"# `flt2dec` | ||
2602 | |||
2603 | This feature is internal to the Rust compiler and is not intended for general use. | ||
3715 | 2604 | ||
3716 | ------------------------ | 2605 | ------------------------ |
2606 | "##, | ||
2607 | }, | ||
2608 | Lint { | ||
2609 | label: "fmt_internals", | ||
2610 | description: r##"# `fmt_internals` | ||
3717 | 2611 | ||
3718 | The `concat_idents` feature adds a macro for concatenating multiple identifiers | 2612 | This feature is internal to the Rust compiler and is not intended for general use. |
3719 | into one identifier. | ||
3720 | 2613 | ||
3721 | ## Examples | 2614 | ------------------------ |
2615 | "##, | ||
2616 | }, | ||
2617 | Lint { | ||
2618 | label: "fn_traits", | ||
2619 | description: r##"# `fn_traits` | ||
2620 | |||
2621 | The tracking issue for this feature is [#29625] | ||
2622 | |||
2623 | See Also: [`unboxed_closures`](../language-features/unboxed-closures.md) | ||
2624 | |||
2625 | [#29625]: https://github.com/rust-lang/rust/issues/29625 | ||
2626 | |||
2627 | ---- | ||
2628 | |||
2629 | The `fn_traits` feature allows for implementation of the [`Fn*`] traits | ||
2630 | for creating custom closure-like types. | ||
2631 | |||
2632 | [`Fn*`]: https://doc.rust-lang.org/std/ops/trait.Fn.html | ||
3722 | 2633 | ||
3723 | ```rust | 2634 | ```rust |
3724 | #![feature(concat_idents)] | 2635 | #![feature(unboxed_closures)] |
2636 | #![feature(fn_traits)] | ||
2637 | |||
2638 | struct Adder { | ||
2639 | a: u32 | ||
2640 | } | ||
2641 | |||
2642 | impl FnOnce<(u32, )> for Adder { | ||
2643 | type Output = u32; | ||
2644 | extern "rust-call" fn call_once(self, b: (u32, )) -> Self::Output { | ||
2645 | self.a + b.0 | ||
2646 | } | ||
2647 | } | ||
3725 | 2648 | ||
3726 | fn main() { | 2649 | fn main() { |
3727 | fn foobar() -> u32 { 23 } | 2650 | let adder = Adder { a: 3 }; |
3728 | let f = concat_idents!(foo, bar); | 2651 | assert_eq!(adder(2), 5); |
3729 | assert_eq!(f(), 23); | ||
3730 | } | 2652 | } |
3731 | ``` | 2653 | ``` |
3732 | "##, | 2654 | "##, |
3733 | }, | 2655 | }, |
3734 | LintCompletion { | 2656 | Lint { |
3735 | label: "format_args_capture", | 2657 | label: "format_args_capture", |
3736 | description: r##"# `format_args_capture` | 2658 | description: r##"# `format_args_capture` |
3737 | 2659 | ||
@@ -3782,16 +2704,914 @@ A non-exhaustive list of macros which benefit from this functionality include: | |||
3782 | - macros in many thirdparty crates, such as `log` | 2704 | - macros in many thirdparty crates, such as `log` |
3783 | "##, | 2705 | "##, |
3784 | }, | 2706 | }, |
3785 | LintCompletion { | 2707 | Lint { |
3786 | label: "print_internals", | 2708 | label: "generators", |
3787 | description: r##"# `print_internals` | 2709 | description: r##"# `generators` |
2710 | |||
2711 | The tracking issue for this feature is: [#43122] | ||
2712 | |||
2713 | [#43122]: https://github.com/rust-lang/rust/issues/43122 | ||
2714 | |||
2715 | ------------------------ | ||
2716 | |||
2717 | The `generators` feature gate in Rust allows you to define generator or | ||
2718 | coroutine literals. A generator is a "resumable function" that syntactically | ||
2719 | resembles a closure but compiles to much different semantics in the compiler | ||
2720 | itself. The primary feature of a generator is that it can be suspended during | ||
2721 | execution to be resumed at a later date. Generators use the `yield` keyword to | ||
2722 | "return", and then the caller can `resume` a generator to resume execution just | ||
2723 | after the `yield` keyword. | ||
2724 | |||
2725 | Generators are an extra-unstable feature in the compiler right now. Added in | ||
2726 | [RFC 2033] they're mostly intended right now as a information/constraint | ||
2727 | gathering phase. The intent is that experimentation can happen on the nightly | ||
2728 | compiler before actual stabilization. A further RFC will be required to | ||
2729 | stabilize generators/coroutines and will likely contain at least a few small | ||
2730 | tweaks to the overall design. | ||
2731 | |||
2732 | [RFC 2033]: https://github.com/rust-lang/rfcs/pull/2033 | ||
2733 | |||
2734 | A syntactical example of a generator is: | ||
2735 | |||
2736 | ```rust | ||
2737 | #![feature(generators, generator_trait)] | ||
2738 | |||
2739 | use std::ops::{Generator, GeneratorState}; | ||
2740 | use std::pin::Pin; | ||
2741 | |||
2742 | fn main() { | ||
2743 | let mut generator = || { | ||
2744 | yield 1; | ||
2745 | return "foo" | ||
2746 | }; | ||
2747 | |||
2748 | match Pin::new(&mut generator).resume(()) { | ||
2749 | GeneratorState::Yielded(1) => {} | ||
2750 | _ => panic!("unexpected value from resume"), | ||
2751 | } | ||
2752 | match Pin::new(&mut generator).resume(()) { | ||
2753 | GeneratorState::Complete("foo") => {} | ||
2754 | _ => panic!("unexpected value from resume"), | ||
2755 | } | ||
2756 | } | ||
2757 | ``` | ||
2758 | |||
2759 | Generators are closure-like literals which can contain a `yield` statement. The | ||
2760 | `yield` statement takes an optional expression of a value to yield out of the | ||
2761 | generator. All generator literals implement the `Generator` trait in the | ||
2762 | `std::ops` module. The `Generator` trait has one main method, `resume`, which | ||
2763 | resumes execution of the generator at the previous suspension point. | ||
2764 | |||
2765 | An example of the control flow of generators is that the following example | ||
2766 | prints all numbers in order: | ||
2767 | |||
2768 | ```rust | ||
2769 | #![feature(generators, generator_trait)] | ||
2770 | |||
2771 | use std::ops::Generator; | ||
2772 | use std::pin::Pin; | ||
2773 | |||
2774 | fn main() { | ||
2775 | let mut generator = || { | ||
2776 | println!("2"); | ||
2777 | yield; | ||
2778 | println!("4"); | ||
2779 | }; | ||
2780 | |||
2781 | println!("1"); | ||
2782 | Pin::new(&mut generator).resume(()); | ||
2783 | println!("3"); | ||
2784 | Pin::new(&mut generator).resume(()); | ||
2785 | println!("5"); | ||
2786 | } | ||
2787 | ``` | ||
2788 | |||
2789 | At this time the main intended use case of generators is an implementation | ||
2790 | primitive for async/await syntax, but generators will likely be extended to | ||
2791 | ergonomic implementations of iterators and other primitives in the future. | ||
2792 | Feedback on the design and usage is always appreciated! | ||
2793 | |||
2794 | ### The `Generator` trait | ||
2795 | |||
2796 | The `Generator` trait in `std::ops` currently looks like: | ||
2797 | |||
2798 | ```rust | ||
2799 | # #![feature(arbitrary_self_types, generator_trait)] | ||
2800 | # use std::ops::GeneratorState; | ||
2801 | # use std::pin::Pin; | ||
2802 | |||
2803 | pub trait Generator<R = ()> { | ||
2804 | type Yield; | ||
2805 | type Return; | ||
2806 | fn resume(self: Pin<&mut Self>, resume: R) -> GeneratorState<Self::Yield, Self::Return>; | ||
2807 | } | ||
2808 | ``` | ||
2809 | |||
2810 | The `Generator::Yield` type is the type of values that can be yielded with the | ||
2811 | `yield` statement. The `Generator::Return` type is the returned type of the | ||
2812 | generator. This is typically the last expression in a generator's definition or | ||
2813 | any value passed to `return` in a generator. The `resume` function is the entry | ||
2814 | point for executing the `Generator` itself. | ||
2815 | |||
2816 | The return value of `resume`, `GeneratorState`, looks like: | ||
2817 | |||
2818 | ```rust | ||
2819 | pub enum GeneratorState<Y, R> { | ||
2820 | Yielded(Y), | ||
2821 | Complete(R), | ||
2822 | } | ||
2823 | ``` | ||
2824 | |||
2825 | The `Yielded` variant indicates that the generator can later be resumed. This | ||
2826 | corresponds to a `yield` point in a generator. The `Complete` variant indicates | ||
2827 | that the generator is complete and cannot be resumed again. Calling `resume` | ||
2828 | after a generator has returned `Complete` will likely result in a panic of the | ||
2829 | program. | ||
2830 | |||
2831 | ### Closure-like semantics | ||
2832 | |||
2833 | The closure-like syntax for generators alludes to the fact that they also have | ||
2834 | closure-like semantics. Namely: | ||
2835 | |||
2836 | * When created, a generator executes no code. A closure literal does not | ||
2837 | actually execute any of the closure's code on construction, and similarly a | ||
2838 | generator literal does not execute any code inside the generator when | ||
2839 | constructed. | ||
2840 | |||
2841 | * Generators can capture outer variables by reference or by move, and this can | ||
2842 | be tweaked with the `move` keyword at the beginning of the closure. Like | ||
2843 | closures all generators will have an implicit environment which is inferred by | ||
2844 | the compiler. Outer variables can be moved into a generator for use as the | ||
2845 | generator progresses. | ||
2846 | |||
2847 | * Generator literals produce a value with a unique type which implements the | ||
2848 | `std::ops::Generator` trait. This allows actual execution of the generator | ||
2849 | through the `Generator::resume` method as well as also naming it in return | ||
2850 | types and such. | ||
2851 | |||
2852 | * Traits like `Send` and `Sync` are automatically implemented for a `Generator` | ||
2853 | depending on the captured variables of the environment. Unlike closures, | ||
2854 | generators also depend on variables live across suspension points. This means | ||
2855 | that although the ambient environment may be `Send` or `Sync`, the generator | ||
2856 | itself may not be due to internal variables live across `yield` points being | ||
2857 | not-`Send` or not-`Sync`. Note that generators do | ||
2858 | not implement traits like `Copy` or `Clone` automatically. | ||
2859 | |||
2860 | * Whenever a generator is dropped it will drop all captured environment | ||
2861 | variables. | ||
2862 | |||
2863 | ### Generators as state machines | ||
2864 | |||
2865 | In the compiler, generators are currently compiled as state machines. Each | ||
2866 | `yield` expression will correspond to a different state that stores all live | ||
2867 | variables over that suspension point. Resumption of a generator will dispatch on | ||
2868 | the current state and then execute internally until a `yield` is reached, at | ||
2869 | which point all state is saved off in the generator and a value is returned. | ||
2870 | |||
2871 | Let's take a look at an example to see what's going on here: | ||
2872 | |||
2873 | ```rust | ||
2874 | #![feature(generators, generator_trait)] | ||
2875 | |||
2876 | use std::ops::Generator; | ||
2877 | use std::pin::Pin; | ||
2878 | |||
2879 | fn main() { | ||
2880 | let ret = "foo"; | ||
2881 | let mut generator = move || { | ||
2882 | yield 1; | ||
2883 | return ret | ||
2884 | }; | ||
2885 | |||
2886 | Pin::new(&mut generator).resume(()); | ||
2887 | Pin::new(&mut generator).resume(()); | ||
2888 | } | ||
2889 | ``` | ||
2890 | |||
2891 | This generator literal will compile down to something similar to: | ||
2892 | |||
2893 | ```rust | ||
2894 | #![feature(arbitrary_self_types, generators, generator_trait)] | ||
2895 | |||
2896 | use std::ops::{Generator, GeneratorState}; | ||
2897 | use std::pin::Pin; | ||
2898 | |||
2899 | fn main() { | ||
2900 | let ret = "foo"; | ||
2901 | let mut generator = { | ||
2902 | enum __Generator { | ||
2903 | Start(&'static str), | ||
2904 | Yield1(&'static str), | ||
2905 | Done, | ||
2906 | } | ||
2907 | |||
2908 | impl Generator for __Generator { | ||
2909 | type Yield = i32; | ||
2910 | type Return = &'static str; | ||
2911 | |||
2912 | fn resume(mut self: Pin<&mut Self>, resume: ()) -> GeneratorState<i32, &'static str> { | ||
2913 | use std::mem; | ||
2914 | match mem::replace(&mut *self, __Generator::Done) { | ||
2915 | __Generator::Start(s) => { | ||
2916 | *self = __Generator::Yield1(s); | ||
2917 | GeneratorState::Yielded(1) | ||
2918 | } | ||
2919 | |||
2920 | __Generator::Yield1(s) => { | ||
2921 | *self = __Generator::Done; | ||
2922 | GeneratorState::Complete(s) | ||
2923 | } | ||
2924 | |||
2925 | __Generator::Done => { | ||
2926 | panic!("generator resumed after completion") | ||
2927 | } | ||
2928 | } | ||
2929 | } | ||
2930 | } | ||
2931 | |||
2932 | __Generator::Start(ret) | ||
2933 | }; | ||
2934 | |||
2935 | Pin::new(&mut generator).resume(()); | ||
2936 | Pin::new(&mut generator).resume(()); | ||
2937 | } | ||
2938 | ``` | ||
2939 | |||
2940 | Notably here we can see that the compiler is generating a fresh type, | ||
2941 | `__Generator` in this case. This type has a number of states (represented here | ||
2942 | as an `enum`) corresponding to each of the conceptual states of the generator. | ||
2943 | At the beginning we're closing over our outer variable `foo` and then that | ||
2944 | variable is also live over the `yield` point, so it's stored in both states. | ||
2945 | |||
2946 | When the generator starts it'll immediately yield 1, but it saves off its state | ||
2947 | just before it does so indicating that it has reached the yield point. Upon | ||
2948 | resuming again we'll execute the `return ret` which returns the `Complete` | ||
2949 | state. | ||
2950 | |||
2951 | Here we can also note that the `Done` state, if resumed, panics immediately as | ||
2952 | it's invalid to resume a completed generator. It's also worth noting that this | ||
2953 | is just a rough desugaring, not a normative specification for what the compiler | ||
2954 | does. | ||
2955 | "##, | ||
2956 | }, | ||
2957 | Lint { | ||
2958 | label: "global_asm", | ||
2959 | description: r##"# `global_asm` | ||
2960 | |||
2961 | The tracking issue for this feature is: [#35119] | ||
2962 | |||
2963 | [#35119]: https://github.com/rust-lang/rust/issues/35119 | ||
2964 | |||
2965 | ------------------------ | ||
2966 | |||
2967 | The `global_asm!` macro allows the programmer to write arbitrary | ||
2968 | assembly outside the scope of a function body, passing it through | ||
2969 | `rustc` and `llvm` to the assembler. That is to say, `global_asm!` is | ||
2970 | equivalent to assembling the asm with an external assembler and then | ||
2971 | linking the resulting object file with the current crate. | ||
2972 | |||
2973 | `global_asm!` fills a role not currently satisfied by either `asm!` | ||
2974 | or `#[naked]` functions. The programmer has _all_ features of the | ||
2975 | assembler at their disposal. The linker will expect to resolve any | ||
2976 | symbols defined in the inline assembly, modulo any symbols marked as | ||
2977 | external. It also means syntax for directives and assembly follow the | ||
2978 | conventions of the assembler in your toolchain. | ||
2979 | |||
2980 | A simple usage looks like this: | ||
2981 | |||
2982 | ```rust,ignore (requires-external-file) | ||
2983 | #![feature(global_asm)] | ||
2984 | # // you also need relevant target_arch cfgs | ||
2985 | global_asm!(include_str!("something_neato.s")); | ||
2986 | ``` | ||
2987 | |||
2988 | And a more complicated usage looks like this: | ||
2989 | |||
2990 | ```rust,no_run | ||
2991 | #![feature(global_asm)] | ||
2992 | # #[cfg(any(target_arch="x86", target_arch="x86_64"))] | ||
2993 | # mod x86 { | ||
2994 | |||
2995 | pub mod sally { | ||
2996 | global_asm!( | ||
2997 | ".global foo", | ||
2998 | "foo:", | ||
2999 | "jmp baz", | ||
3000 | ); | ||
3001 | |||
3002 | #[no_mangle] | ||
3003 | pub unsafe extern "C" fn baz() {} | ||
3004 | } | ||
3005 | |||
3006 | // the symbols `foo` and `bar` are global, no matter where | ||
3007 | // `global_asm!` was used. | ||
3008 | extern "C" { | ||
3009 | fn foo(); | ||
3010 | fn bar(); | ||
3011 | } | ||
3012 | |||
3013 | pub mod harry { | ||
3014 | global_asm!( | ||
3015 | ".global bar", | ||
3016 | "bar:", | ||
3017 | "jmp quux", | ||
3018 | ); | ||
3019 | |||
3020 | #[no_mangle] | ||
3021 | pub unsafe extern "C" fn quux() {} | ||
3022 | } | ||
3023 | # } | ||
3024 | ``` | ||
3025 | |||
3026 | You may use `global_asm!` multiple times, anywhere in your crate, in | ||
3027 | whatever way suits you. However, you should not rely on assembler state | ||
3028 | (e.g. assembler macros) defined in one `global_asm!` to be available in | ||
3029 | another one. It is implementation-defined whether the multiple usages | ||
3030 | are concatenated into one or assembled separately. | ||
3031 | |||
3032 | `global_asm!` also supports `const` operands like `asm!`, which allows | ||
3033 | constants defined in Rust to be used in assembly code: | ||
3034 | |||
3035 | ```rust,no_run | ||
3036 | #![feature(global_asm)] | ||
3037 | # #[cfg(any(target_arch="x86", target_arch="x86_64"))] | ||
3038 | # mod x86 { | ||
3039 | const C: i32 = 1234; | ||
3040 | global_asm!( | ||
3041 | ".global bar", | ||
3042 | "bar: .word {c}", | ||
3043 | c = const C, | ||
3044 | ); | ||
3045 | # } | ||
3046 | ``` | ||
3047 | |||
3048 | The syntax for passing operands is the same as `asm!` except that only | ||
3049 | `const` operands are allowed. Refer to the [asm](asm.md) documentation | ||
3050 | for more details. | ||
3051 | |||
3052 | On x86, the assembly code will use intel syntax by default. You can | ||
3053 | override this by adding `options(att_syntax)` at the end of the macro | ||
3054 | arguments list: | ||
3055 | |||
3056 | ```rust,no_run | ||
3057 | #![feature(global_asm)] | ||
3058 | # #[cfg(any(target_arch="x86", target_arch="x86_64"))] | ||
3059 | # mod x86 { | ||
3060 | global_asm!("movl ${}, %ecx", const 5, options(att_syntax)); | ||
3061 | // is equivalent to | ||
3062 | global_asm!("mov ecx, {}", const 5); | ||
3063 | # } | ||
3064 | ``` | ||
3065 | |||
3066 | ------------------------ | ||
3067 | |||
3068 | If you don't need quite as much power and flexibility as | ||
3069 | `global_asm!` provides, and you don't mind restricting your inline | ||
3070 | assembly to `fn` bodies only, you might try the | ||
3071 | [asm](asm.md) feature instead. | ||
3072 | "##, | ||
3073 | }, | ||
3074 | Lint { | ||
3075 | label: "impl_trait_in_bindings", | ||
3076 | description: r##"# `impl_trait_in_bindings` | ||
3077 | |||
3078 | The tracking issue for this feature is: [#63065] | ||
3079 | |||
3080 | [#63065]: https://github.com/rust-lang/rust/issues/63065 | ||
3081 | |||
3082 | ------------------------ | ||
3083 | |||
3084 | The `impl_trait_in_bindings` feature gate lets you use `impl Trait` syntax in | ||
3085 | `let`, `static`, and `const` bindings. | ||
3086 | |||
3087 | A simple example is: | ||
3088 | |||
3089 | ```rust | ||
3090 | #![feature(impl_trait_in_bindings)] | ||
3091 | |||
3092 | use std::fmt::Debug; | ||
3093 | |||
3094 | fn main() { | ||
3095 | let a: impl Debug + Clone = 42; | ||
3096 | let b = a.clone(); | ||
3097 | println!("{:?}", b); // prints `42` | ||
3098 | } | ||
3099 | ``` | ||
3100 | |||
3101 | Note however that because the types of `a` and `b` are opaque in the above | ||
3102 | example, calling inherent methods or methods outside of the specified traits | ||
3103 | (e.g., `a.abs()` or `b.abs()`) is not allowed, and yields an error. | ||
3104 | "##, | ||
3105 | }, | ||
3106 | Lint { | ||
3107 | label: "infer_static_outlives_requirements", | ||
3108 | description: r##"# `infer_static_outlives_requirements` | ||
3109 | |||
3110 | The tracking issue for this feature is: [#54185] | ||
3111 | |||
3112 | [#54185]: https://github.com/rust-lang/rust/issues/54185 | ||
3113 | |||
3114 | ------------------------ | ||
3115 | The `infer_static_outlives_requirements` feature indicates that certain | ||
3116 | `'static` outlives requirements can be inferred by the compiler rather than | ||
3117 | stating them explicitly. | ||
3118 | |||
3119 | Note: It is an accompanying feature to `infer_outlives_requirements`, | ||
3120 | which must be enabled to infer outlives requirements. | ||
3121 | |||
3122 | For example, currently generic struct definitions that contain | ||
3123 | references, require where-clauses of the form T: 'static. By using | ||
3124 | this feature the outlives predicates will be inferred, although | ||
3125 | they may still be written explicitly. | ||
3126 | |||
3127 | ```rust,ignore (pseudo-Rust) | ||
3128 | struct Foo<U> where U: 'static { // <-- currently required | ||
3129 | bar: Bar<U> | ||
3130 | } | ||
3131 | struct Bar<T: 'static> { | ||
3132 | x: T, | ||
3133 | } | ||
3134 | ``` | ||
3135 | |||
3136 | |||
3137 | ## Examples: | ||
3138 | |||
3139 | ```rust,ignore (pseudo-Rust) | ||
3140 | #![feature(infer_outlives_requirements)] | ||
3141 | #![feature(infer_static_outlives_requirements)] | ||
3142 | |||
3143 | #[rustc_outlives] | ||
3144 | // Implicitly infer U: 'static | ||
3145 | struct Foo<U> { | ||
3146 | bar: Bar<U> | ||
3147 | } | ||
3148 | struct Bar<T: 'static> { | ||
3149 | x: T, | ||
3150 | } | ||
3151 | ``` | ||
3152 | "##, | ||
3153 | }, | ||
3154 | Lint { | ||
3155 | label: "inline_const", | ||
3156 | description: r##"# `inline_const` | ||
3157 | |||
3158 | The tracking issue for this feature is: [#76001] | ||
3159 | |||
3160 | ------ | ||
3161 | |||
3162 | This feature allows you to use inline constant expressions. For example, you can | ||
3163 | turn this code: | ||
3164 | |||
3165 | ```rust | ||
3166 | # fn add_one(x: i32) -> i32 { x + 1 } | ||
3167 | const MY_COMPUTATION: i32 = 1 + 2 * 3 / 4; | ||
3168 | |||
3169 | fn main() { | ||
3170 | let x = add_one(MY_COMPUTATION); | ||
3171 | } | ||
3172 | ``` | ||
3173 | |||
3174 | into this code: | ||
3175 | |||
3176 | ```rust | ||
3177 | #![feature(inline_const)] | ||
3178 | |||
3179 | # fn add_one(x: i32) -> i32 { x + 1 } | ||
3180 | fn main() { | ||
3181 | let x = add_one(const { 1 + 2 * 3 / 4 }); | ||
3182 | } | ||
3183 | ``` | ||
3184 | |||
3185 | You can also use inline constant expressions in patterns: | ||
3186 | |||
3187 | ```rust | ||
3188 | #![feature(inline_const)] | ||
3189 | |||
3190 | const fn one() -> i32 { 1 } | ||
3191 | |||
3192 | let some_int = 3; | ||
3193 | match some_int { | ||
3194 | const { 1 + 2 } => println!("Matched 1 + 2"), | ||
3195 | const { one() } => println!("Matched const fn returning 1"), | ||
3196 | _ => println!("Didn't match anything :("), | ||
3197 | } | ||
3198 | ``` | ||
3199 | |||
3200 | [#76001]: https://github.com/rust-lang/rust/issues/76001 | ||
3201 | "##, | ||
3202 | }, | ||
3203 | Lint { | ||
3204 | label: "int_error_internals", | ||
3205 | description: r##"# `int_error_internals` | ||
3206 | |||
3207 | This feature is internal to the Rust compiler and is not intended for general use. | ||
3208 | |||
3209 | ------------------------ | ||
3210 | "##, | ||
3211 | }, | ||
3212 | Lint { | ||
3213 | label: "internal_output_capture", | ||
3214 | description: r##"# `internal_output_capture` | ||
3215 | |||
3216 | This feature is internal to the Rust compiler and is not intended for general use. | ||
3217 | |||
3218 | ------------------------ | ||
3219 | "##, | ||
3220 | }, | ||
3221 | Lint { | ||
3222 | label: "intra_doc_pointers", | ||
3223 | description: r##"# `intra-doc-pointers` | ||
3224 | |||
3225 | The tracking issue for this feature is: [#80896] | ||
3226 | |||
3227 | [#80896]: https://github.com/rust-lang/rust/issues/80896 | ||
3228 | |||
3229 | ------------------------ | ||
3230 | |||
3231 | Rustdoc does not currently allow disambiguating between `*const` and `*mut`, and | ||
3232 | raw pointers in intra-doc links are unstable until it does. | ||
3233 | |||
3234 | ```rust | ||
3235 | #![feature(intra_doc_pointers)] | ||
3236 | //! [pointer::add] | ||
3237 | ``` | ||
3238 | "##, | ||
3239 | }, | ||
3240 | Lint { | ||
3241 | label: "intrinsics", | ||
3242 | description: r##"# `intrinsics` | ||
3243 | |||
3244 | The tracking issue for this feature is: None. | ||
3245 | |||
3246 | Intrinsics are never intended to be stable directly, but intrinsics are often | ||
3247 | exported in some sort of stable manner. Prefer using the stable interfaces to | ||
3248 | the intrinsic directly when you can. | ||
3249 | |||
3250 | ------------------------ | ||
3251 | |||
3252 | |||
3253 | These are imported as if they were FFI functions, with the special | ||
3254 | `rust-intrinsic` ABI. For example, if one was in a freestanding | ||
3255 | context, but wished to be able to `transmute` between types, and | ||
3256 | perform efficient pointer arithmetic, one would import those functions | ||
3257 | via a declaration like | ||
3258 | |||
3259 | ```rust | ||
3260 | #![feature(intrinsics)] | ||
3261 | # fn main() {} | ||
3262 | |||
3263 | extern "rust-intrinsic" { | ||
3264 | fn transmute<T, U>(x: T) -> U; | ||
3265 | |||
3266 | fn offset<T>(dst: *const T, offset: isize) -> *const T; | ||
3267 | } | ||
3268 | ``` | ||
3269 | |||
3270 | As with any other FFI functions, these are always `unsafe` to call. | ||
3271 | "##, | ||
3272 | }, | ||
3273 | Lint { | ||
3274 | label: "is_sorted", | ||
3275 | description: r##"# `is_sorted` | ||
3276 | |||
3277 | The tracking issue for this feature is: [#53485] | ||
3278 | |||
3279 | [#53485]: https://github.com/rust-lang/rust/issues/53485 | ||
3280 | |||
3281 | ------------------------ | ||
3282 | |||
3283 | Add the methods `is_sorted`, `is_sorted_by` and `is_sorted_by_key` to `[T]`; | ||
3284 | add the methods `is_sorted`, `is_sorted_by` and `is_sorted_by_key` to | ||
3285 | `Iterator`. | ||
3286 | "##, | ||
3287 | }, | ||
3288 | Lint { | ||
3289 | label: "lang_items", | ||
3290 | description: r##"# `lang_items` | ||
3291 | |||
3292 | The tracking issue for this feature is: None. | ||
3293 | |||
3294 | ------------------------ | ||
3295 | |||
3296 | The `rustc` compiler has certain pluggable operations, that is, | ||
3297 | functionality that isn't hard-coded into the language, but is | ||
3298 | implemented in libraries, with a special marker to tell the compiler | ||
3299 | it exists. The marker is the attribute `#[lang = "..."]` and there are | ||
3300 | various different values of `...`, i.e. various different 'lang | ||
3301 | items'. | ||
3302 | |||
3303 | For example, `Box` pointers require two lang items, one for allocation | ||
3304 | and one for deallocation. A freestanding program that uses the `Box` | ||
3305 | sugar for dynamic allocations via `malloc` and `free`: | ||
3306 | |||
3307 | ```rust,ignore (libc-is-finicky) | ||
3308 | #![feature(lang_items, box_syntax, start, libc, core_intrinsics, rustc_private)] | ||
3309 | #![no_std] | ||
3310 | use core::intrinsics; | ||
3311 | use core::panic::PanicInfo; | ||
3312 | |||
3313 | extern crate libc; | ||
3314 | |||
3315 | #[lang = "owned_box"] | ||
3316 | pub struct Box<T>(*mut T); | ||
3317 | |||
3318 | #[lang = "exchange_malloc"] | ||
3319 | unsafe fn allocate(size: usize, _align: usize) -> *mut u8 { | ||
3320 | let p = libc::malloc(size as libc::size_t) as *mut u8; | ||
3321 | |||
3322 | // Check if `malloc` failed: | ||
3323 | if p as usize == 0 { | ||
3324 | intrinsics::abort(); | ||
3325 | } | ||
3326 | |||
3327 | p | ||
3328 | } | ||
3329 | |||
3330 | #[lang = "box_free"] | ||
3331 | unsafe fn box_free<T: ?Sized>(ptr: *mut T) { | ||
3332 | libc::free(ptr as *mut libc::c_void) | ||
3333 | } | ||
3334 | |||
3335 | #[start] | ||
3336 | fn main(_argc: isize, _argv: *const *const u8) -> isize { | ||
3337 | let _x = box 1; | ||
3338 | |||
3339 | 0 | ||
3340 | } | ||
3341 | |||
3342 | #[lang = "eh_personality"] extern fn rust_eh_personality() {} | ||
3343 | #[lang = "panic_impl"] extern fn rust_begin_panic(info: &PanicInfo) -> ! { unsafe { intrinsics::abort() } } | ||
3344 | #[no_mangle] pub extern fn rust_eh_register_frames () {} | ||
3345 | #[no_mangle] pub extern fn rust_eh_unregister_frames () {} | ||
3346 | ``` | ||
3347 | |||
3348 | Note the use of `abort`: the `exchange_malloc` lang item is assumed to | ||
3349 | return a valid pointer, and so needs to do the check internally. | ||
3350 | |||
3351 | Other features provided by lang items include: | ||
3352 | |||
3353 | - overloadable operators via traits: the traits corresponding to the | ||
3354 | `==`, `<`, dereferencing (`*`) and `+` (etc.) operators are all | ||
3355 | marked with lang items; those specific four are `eq`, `ord`, | ||
3356 | `deref`, and `add` respectively. | ||
3357 | - stack unwinding and general failure; the `eh_personality`, | ||
3358 | `panic` and `panic_bounds_check` lang items. | ||
3359 | - the traits in `std::marker` used to indicate types of | ||
3360 | various kinds; lang items `send`, `sync` and `copy`. | ||
3361 | - the marker types and variance indicators found in | ||
3362 | `std::marker`; lang items `covariant_type`, | ||
3363 | `contravariant_lifetime`, etc. | ||
3364 | |||
3365 | Lang items are loaded lazily by the compiler; e.g. if one never uses | ||
3366 | `Box` then there is no need to define functions for `exchange_malloc` | ||
3367 | and `box_free`. `rustc` will emit an error when an item is needed | ||
3368 | but not found in the current crate or any that it depends on. | ||
3369 | |||
3370 | Most lang items are defined by `libcore`, but if you're trying to build | ||
3371 | an executable without the standard library, you'll run into the need | ||
3372 | for lang items. The rest of this page focuses on this use-case, even though | ||
3373 | lang items are a bit broader than that. | ||
3374 | |||
3375 | ### Using libc | ||
3376 | |||
3377 | In order to build a `#[no_std]` executable we will need libc as a dependency. | ||
3378 | We can specify this using our `Cargo.toml` file: | ||
3379 | |||
3380 | ```toml | ||
3381 | [dependencies] | ||
3382 | libc = { version = "0.2.14", default-features = false } | ||
3383 | ``` | ||
3384 | |||
3385 | Note that the default features have been disabled. This is a critical step - | ||
3386 | **the default features of libc include the standard library and so must be | ||
3387 | disabled.** | ||
3388 | |||
3389 | ### Writing an executable without stdlib | ||
3390 | |||
3391 | Controlling the entry point is possible in two ways: the `#[start]` attribute, | ||
3392 | or overriding the default shim for the C `main` function with your own. | ||
3393 | |||
3394 | The function marked `#[start]` is passed the command line parameters | ||
3395 | in the same format as C: | ||
3396 | |||
3397 | ```rust,ignore (libc-is-finicky) | ||
3398 | #![feature(lang_items, core_intrinsics, rustc_private)] | ||
3399 | #![feature(start)] | ||
3400 | #![no_std] | ||
3401 | use core::intrinsics; | ||
3402 | use core::panic::PanicInfo; | ||
3403 | |||
3404 | // Pull in the system libc library for what crt0.o likely requires. | ||
3405 | extern crate libc; | ||
3406 | |||
3407 | // Entry point for this program. | ||
3408 | #[start] | ||
3409 | fn start(_argc: isize, _argv: *const *const u8) -> isize { | ||
3410 | 0 | ||
3411 | } | ||
3412 | |||
3413 | // These functions are used by the compiler, but not | ||
3414 | // for a bare-bones hello world. These are normally | ||
3415 | // provided by libstd. | ||
3416 | #[lang = "eh_personality"] | ||
3417 | #[no_mangle] | ||
3418 | pub extern fn rust_eh_personality() { | ||
3419 | } | ||
3420 | |||
3421 | #[lang = "panic_impl"] | ||
3422 | #[no_mangle] | ||
3423 | pub extern fn rust_begin_panic(info: &PanicInfo) -> ! { | ||
3424 | unsafe { intrinsics::abort() } | ||
3425 | } | ||
3426 | ``` | ||
3427 | |||
3428 | To override the compiler-inserted `main` shim, one has to disable it | ||
3429 | with `#![no_main]` and then create the appropriate symbol with the | ||
3430 | correct ABI and the correct name, which requires overriding the | ||
3431 | compiler's name mangling too: | ||
3432 | |||
3433 | ```rust,ignore (libc-is-finicky) | ||
3434 | #![feature(lang_items, core_intrinsics, rustc_private)] | ||
3435 | #![feature(start)] | ||
3436 | #![no_std] | ||
3437 | #![no_main] | ||
3438 | use core::intrinsics; | ||
3439 | use core::panic::PanicInfo; | ||
3440 | |||
3441 | // Pull in the system libc library for what crt0.o likely requires. | ||
3442 | extern crate libc; | ||
3443 | |||
3444 | // Entry point for this program. | ||
3445 | #[no_mangle] // ensure that this symbol is called `main` in the output | ||
3446 | pub extern fn main(_argc: i32, _argv: *const *const u8) -> i32 { | ||
3447 | 0 | ||
3448 | } | ||
3449 | |||
3450 | // These functions are used by the compiler, but not | ||
3451 | // for a bare-bones hello world. These are normally | ||
3452 | // provided by libstd. | ||
3453 | #[lang = "eh_personality"] | ||
3454 | #[no_mangle] | ||
3455 | pub extern fn rust_eh_personality() { | ||
3456 | } | ||
3457 | |||
3458 | #[lang = "panic_impl"] | ||
3459 | #[no_mangle] | ||
3460 | pub extern fn rust_begin_panic(info: &PanicInfo) -> ! { | ||
3461 | unsafe { intrinsics::abort() } | ||
3462 | } | ||
3463 | ``` | ||
3464 | |||
3465 | In many cases, you may need to manually link to the `compiler_builtins` crate | ||
3466 | when building a `no_std` binary. You may observe this via linker error messages | ||
3467 | such as "```undefined reference to `__rust_probestack'```". | ||
3468 | |||
3469 | ## More about the language items | ||
3470 | |||
3471 | The compiler currently makes a few assumptions about symbols which are | ||
3472 | available in the executable to call. Normally these functions are provided by | ||
3473 | the standard library, but without it you must define your own. These symbols | ||
3474 | are called "language items", and they each have an internal name, and then a | ||
3475 | signature that an implementation must conform to. | ||
3476 | |||
3477 | The first of these functions, `rust_eh_personality`, is used by the failure | ||
3478 | mechanisms of the compiler. This is often mapped to GCC's personality function | ||
3479 | (see the [libstd implementation][unwind] for more information), but crates | ||
3480 | which do not trigger a panic can be assured that this function is never | ||
3481 | called. The language item's name is `eh_personality`. | ||
3482 | |||
3483 | [unwind]: https://github.com/rust-lang/rust/blob/master/library/panic_unwind/src/gcc.rs | ||
3484 | |||
3485 | The second function, `rust_begin_panic`, is also used by the failure mechanisms of the | ||
3486 | compiler. When a panic happens, this controls the message that's displayed on | ||
3487 | the screen. While the language item's name is `panic_impl`, the symbol name is | ||
3488 | `rust_begin_panic`. | ||
3489 | |||
3490 | Finally, a `eh_catch_typeinfo` static is needed for certain targets which | ||
3491 | implement Rust panics on top of C++ exceptions. | ||
3492 | |||
3493 | ## List of all language items | ||
3494 | |||
3495 | This is a list of all language items in Rust along with where they are located in | ||
3496 | the source code. | ||
3497 | |||
3498 | - Primitives | ||
3499 | - `i8`: `libcore/num/mod.rs` | ||
3500 | - `i16`: `libcore/num/mod.rs` | ||
3501 | - `i32`: `libcore/num/mod.rs` | ||
3502 | - `i64`: `libcore/num/mod.rs` | ||
3503 | - `i128`: `libcore/num/mod.rs` | ||
3504 | - `isize`: `libcore/num/mod.rs` | ||
3505 | - `u8`: `libcore/num/mod.rs` | ||
3506 | - `u16`: `libcore/num/mod.rs` | ||
3507 | - `u32`: `libcore/num/mod.rs` | ||
3508 | - `u64`: `libcore/num/mod.rs` | ||
3509 | - `u128`: `libcore/num/mod.rs` | ||
3510 | - `usize`: `libcore/num/mod.rs` | ||
3511 | - `f32`: `libstd/f32.rs` | ||
3512 | - `f64`: `libstd/f64.rs` | ||
3513 | - `char`: `libcore/char.rs` | ||
3514 | - `slice`: `liballoc/slice.rs` | ||
3515 | - `str`: `liballoc/str.rs` | ||
3516 | - `const_ptr`: `libcore/ptr.rs` | ||
3517 | - `mut_ptr`: `libcore/ptr.rs` | ||
3518 | - `unsafe_cell`: `libcore/cell.rs` | ||
3519 | - Runtime | ||
3520 | - `start`: `libstd/rt.rs` | ||
3521 | - `eh_personality`: `libpanic_unwind/emcc.rs` (EMCC) | ||
3522 | - `eh_personality`: `libpanic_unwind/gcc.rs` (GNU) | ||
3523 | - `eh_personality`: `libpanic_unwind/seh.rs` (SEH) | ||
3524 | - `eh_catch_typeinfo`: `libpanic_unwind/emcc.rs` (EMCC) | ||
3525 | - `panic`: `libcore/panicking.rs` | ||
3526 | - `panic_bounds_check`: `libcore/panicking.rs` | ||
3527 | - `panic_impl`: `libcore/panicking.rs` | ||
3528 | - `panic_impl`: `libstd/panicking.rs` | ||
3529 | - Allocations | ||
3530 | - `owned_box`: `liballoc/boxed.rs` | ||
3531 | - `exchange_malloc`: `liballoc/heap.rs` | ||
3532 | - `box_free`: `liballoc/heap.rs` | ||
3533 | - Operands | ||
3534 | - `not`: `libcore/ops/bit.rs` | ||
3535 | - `bitand`: `libcore/ops/bit.rs` | ||
3536 | - `bitor`: `libcore/ops/bit.rs` | ||
3537 | - `bitxor`: `libcore/ops/bit.rs` | ||
3538 | - `shl`: `libcore/ops/bit.rs` | ||
3539 | - `shr`: `libcore/ops/bit.rs` | ||
3540 | - `bitand_assign`: `libcore/ops/bit.rs` | ||
3541 | - `bitor_assign`: `libcore/ops/bit.rs` | ||
3542 | - `bitxor_assign`: `libcore/ops/bit.rs` | ||
3543 | - `shl_assign`: `libcore/ops/bit.rs` | ||
3544 | - `shr_assign`: `libcore/ops/bit.rs` | ||
3545 | - `deref`: `libcore/ops/deref.rs` | ||
3546 | - `deref_mut`: `libcore/ops/deref.rs` | ||
3547 | - `index`: `libcore/ops/index.rs` | ||
3548 | - `index_mut`: `libcore/ops/index.rs` | ||
3549 | - `add`: `libcore/ops/arith.rs` | ||
3550 | - `sub`: `libcore/ops/arith.rs` | ||
3551 | - `mul`: `libcore/ops/arith.rs` | ||
3552 | - `div`: `libcore/ops/arith.rs` | ||
3553 | - `rem`: `libcore/ops/arith.rs` | ||
3554 | - `neg`: `libcore/ops/arith.rs` | ||
3555 | - `add_assign`: `libcore/ops/arith.rs` | ||
3556 | - `sub_assign`: `libcore/ops/arith.rs` | ||
3557 | - `mul_assign`: `libcore/ops/arith.rs` | ||
3558 | - `div_assign`: `libcore/ops/arith.rs` | ||
3559 | - `rem_assign`: `libcore/ops/arith.rs` | ||
3560 | - `eq`: `libcore/cmp.rs` | ||
3561 | - `ord`: `libcore/cmp.rs` | ||
3562 | - Functions | ||
3563 | - `fn`: `libcore/ops/function.rs` | ||
3564 | - `fn_mut`: `libcore/ops/function.rs` | ||
3565 | - `fn_once`: `libcore/ops/function.rs` | ||
3566 | - `generator_state`: `libcore/ops/generator.rs` | ||
3567 | - `generator`: `libcore/ops/generator.rs` | ||
3568 | - Other | ||
3569 | - `coerce_unsized`: `libcore/ops/unsize.rs` | ||
3570 | - `drop`: `libcore/ops/drop.rs` | ||
3571 | - `drop_in_place`: `libcore/ptr.rs` | ||
3572 | - `clone`: `libcore/clone.rs` | ||
3573 | - `copy`: `libcore/marker.rs` | ||
3574 | - `send`: `libcore/marker.rs` | ||
3575 | - `sized`: `libcore/marker.rs` | ||
3576 | - `unsize`: `libcore/marker.rs` | ||
3577 | - `sync`: `libcore/marker.rs` | ||
3578 | - `phantom_data`: `libcore/marker.rs` | ||
3579 | - `discriminant_kind`: `libcore/marker.rs` | ||
3580 | - `freeze`: `libcore/marker.rs` | ||
3581 | - `debug_trait`: `libcore/fmt/mod.rs` | ||
3582 | - `non_zero`: `libcore/nonzero.rs` | ||
3583 | - `arc`: `liballoc/sync.rs` | ||
3584 | - `rc`: `liballoc/rc.rs` | ||
3585 | "##, | ||
3586 | }, | ||
3587 | Lint { | ||
3588 | label: "libstd_sys_internals", | ||
3589 | description: r##"# `libstd_sys_internals` | ||
3788 | 3590 | ||
3789 | This feature is internal to the Rust compiler and is not intended for general use. | 3591 | This feature is internal to the Rust compiler and is not intended for general use. |
3790 | 3592 | ||
3791 | ------------------------ | 3593 | ------------------------ |
3792 | "##, | 3594 | "##, |
3793 | }, | 3595 | }, |
3794 | LintCompletion { | 3596 | Lint { |
3597 | label: "libstd_thread_internals", | ||
3598 | description: r##"# `libstd_thread_internals` | ||
3599 | |||
3600 | This feature is internal to the Rust compiler and is not intended for general use. | ||
3601 | |||
3602 | ------------------------ | ||
3603 | "##, | ||
3604 | }, | ||
3605 | Lint { | ||
3606 | label: "link_cfg", | ||
3607 | description: r##"# `link_cfg` | ||
3608 | |||
3609 | This feature is internal to the Rust compiler and is not intended for general use. | ||
3610 | |||
3611 | ------------------------ | ||
3612 | "##, | ||
3613 | }, | ||
3614 | Lint { | ||
3795 | label: "llvm_asm", | 3615 | label: "llvm_asm", |
3796 | description: r##"# `llvm_asm` | 3616 | description: r##"# `llvm_asm` |
3797 | 3617 | ||
@@ -3988,188 +3808,544 @@ If you need more power and don't mind losing some of the niceties of | |||
3988 | `llvm_asm!`, check out [global_asm](global-asm.md). | 3808 | `llvm_asm!`, check out [global_asm](global-asm.md). |
3989 | "##, | 3809 | "##, |
3990 | }, | 3810 | }, |
3991 | LintCompletion { | 3811 | Lint { |
3992 | label: "core_intrinsics", | 3812 | label: "marker_trait_attr", |
3993 | description: r##"# `core_intrinsics` | 3813 | description: r##"# `marker_trait_attr` |
3994 | 3814 | ||
3995 | This feature is internal to the Rust compiler and is not intended for general use. | 3815 | The tracking issue for this feature is: [#29864] |
3816 | |||
3817 | [#29864]: https://github.com/rust-lang/rust/issues/29864 | ||
3996 | 3818 | ||
3997 | ------------------------ | 3819 | ------------------------ |
3820 | |||
3821 | Normally, Rust keeps you from adding trait implementations that could | ||
3822 | overlap with each other, as it would be ambiguous which to use. This | ||
3823 | feature, however, carves out an exception to that rule: a trait can | ||
3824 | opt-in to having overlapping implementations, at the cost that those | ||
3825 | implementations are not allowed to override anything (and thus the | ||
3826 | trait itself cannot have any associated items, as they're pointless | ||
3827 | when they'd need to do the same thing for every type anyway). | ||
3828 | |||
3829 | ```rust | ||
3830 | #![feature(marker_trait_attr)] | ||
3831 | |||
3832 | #[marker] trait CheapToClone: Clone {} | ||
3833 | |||
3834 | impl<T: Copy> CheapToClone for T {} | ||
3835 | |||
3836 | // These could potentially overlap with the blanket implementation above, | ||
3837 | // so are only allowed because CheapToClone is a marker trait. | ||
3838 | impl<T: CheapToClone, U: CheapToClone> CheapToClone for (T, U) {} | ||
3839 | impl<T: CheapToClone> CheapToClone for std::ops::Range<T> {} | ||
3840 | |||
3841 | fn cheap_clone<T: CheapToClone>(t: T) -> T { | ||
3842 | t.clone() | ||
3843 | } | ||
3844 | ``` | ||
3845 | |||
3846 | This is expected to replace the unstable `overlapping_marker_traits` | ||
3847 | feature, which applied to all empty traits (without needing an opt-in). | ||
3998 | "##, | 3848 | "##, |
3999 | }, | 3849 | }, |
4000 | LintCompletion { | 3850 | Lint { |
4001 | label: "trace_macros", | 3851 | label: "native_link_modifiers", |
4002 | description: r##"# `trace_macros` | 3852 | description: r##"# `native_link_modifiers` |
4003 | 3853 | ||
4004 | The tracking issue for this feature is [#29598]. | 3854 | The tracking issue for this feature is: [#81490] |
4005 | 3855 | ||
4006 | [#29598]: https://github.com/rust-lang/rust/issues/29598 | 3856 | [#81490]: https://github.com/rust-lang/rust/issues/81490 |
4007 | 3857 | ||
4008 | ------------------------ | 3858 | ------------------------ |
4009 | 3859 | ||
4010 | With `trace_macros` you can trace the expansion of macros in your code. | 3860 | The `native_link_modifiers` feature allows you to use the `modifiers` syntax with the `#[link(..)]` attribute. |
4011 | 3861 | ||
4012 | ## Examples | 3862 | Modifiers are specified as a comma-delimited string with each modifier prefixed with either a `+` or `-` to indicate that the modifier is enabled or disabled, respectively. The last boolean value specified for a given modifier wins. |
3863 | "##, | ||
3864 | }, | ||
3865 | Lint { | ||
3866 | label: "native_link_modifiers_as_needed", | ||
3867 | description: r##"# `native_link_modifiers_as_needed` | ||
4013 | 3868 | ||
4014 | ```rust | 3869 | The tracking issue for this feature is: [#81490] |
4015 | #![feature(trace_macros)] | ||
4016 | 3870 | ||
4017 | fn main() { | 3871 | [#81490]: https://github.com/rust-lang/rust/issues/81490 |
4018 | trace_macros!(true); | ||
4019 | println!("Hello, Rust!"); | ||
4020 | trace_macros!(false); | ||
4021 | } | ||
4022 | ``` | ||
4023 | 3872 | ||
4024 | The `cargo build` output: | 3873 | ------------------------ |
4025 | 3874 | ||
4026 | ```txt | 3875 | The `native_link_modifiers_as_needed` feature allows you to use the `as-needed` modifier. |
4027 | note: trace_macro | ||
4028 | --> src/main.rs:5:5 | ||
4029 | | | ||
4030 | 5 | println!("Hello, Rust!"); | ||
4031 | | ^^^^^^^^^^^^^^^^^^^^^^^^^ | ||
4032 | | | ||
4033 | = note: expanding `println! { "Hello, Rust!" }` | ||
4034 | = note: to `print ! ( concat ! ( "Hello, Rust!" , "\n" ) )` | ||
4035 | = note: expanding `print! { concat ! ( "Hello, Rust!" , "\n" ) }` | ||
4036 | = note: to `$crate :: io :: _print ( format_args ! ( concat ! ( "Hello, Rust!" , "\n" ) ) | ||
4037 | )` | ||
4038 | 3876 | ||
4039 | Finished dev [unoptimized + debuginfo] target(s) in 0.60 secs | 3877 | `as-needed` is only compatible with the `dynamic` and `framework` linking kinds. Using any other kind will result in a compiler error. |
4040 | ``` | 3878 | |
3879 | `+as-needed` means that the library will be actually linked only if it satisfies some undefined symbols at the point at which it is specified on the command line, making it similar to static libraries in this regard. | ||
3880 | |||
3881 | This modifier translates to `--as-needed` for ld-like linkers, and to `-dead_strip_dylibs` / `-needed_library` / `-needed_framework` for ld64. | ||
3882 | The modifier does nothing for linkers that don't support it (e.g. `link.exe`). | ||
3883 | |||
3884 | The default for this modifier is unclear, some targets currently specify it as `+as-needed`, some do not. We may want to try making `+as-needed` a default for all targets. | ||
4041 | "##, | 3885 | "##, |
4042 | }, | 3886 | }, |
4043 | LintCompletion { | 3887 | Lint { |
4044 | label: "update_panic_count", | 3888 | label: "native_link_modifiers_bundle", |
4045 | description: r##"# `update_panic_count` | 3889 | description: r##"# `native_link_modifiers_bundle` |
4046 | 3890 | ||
4047 | This feature is internal to the Rust compiler and is not intended for general use. | 3891 | The tracking issue for this feature is: [#81490] |
3892 | |||
3893 | [#81490]: https://github.com/rust-lang/rust/issues/81490 | ||
4048 | 3894 | ||
4049 | ------------------------ | 3895 | ------------------------ |
3896 | |||
3897 | The `native_link_modifiers_bundle` feature allows you to use the `bundle` modifier. | ||
3898 | |||
3899 | Only compatible with the `static` linking kind. Using any other kind will result in a compiler error. | ||
3900 | |||
3901 | `+bundle` means objects from the static library are bundled into the produced crate (a rlib, for example) and are used from this crate later during linking of the final binary. | ||
3902 | |||
3903 | `-bundle` means the static library is included into the produced rlib "by name" and object files from it are included only during linking of the final binary, the file search by that name is also performed during final linking. | ||
3904 | |||
3905 | This modifier is supposed to supersede the `static-nobundle` linking kind defined by [RFC 1717](https://github.com/rust-lang/rfcs/pull/1717). | ||
3906 | |||
3907 | The default for this modifier is currently `+bundle`, but it could be changed later on some future edition boundary. | ||
4050 | "##, | 3908 | "##, |
4051 | }, | 3909 | }, |
4052 | LintCompletion { | 3910 | Lint { |
4053 | label: "core_private_bignum", | 3911 | label: "native_link_modifiers_verbatim", |
4054 | description: r##"# `core_private_bignum` | 3912 | description: r##"# `native_link_modifiers_verbatim` |
4055 | 3913 | ||
4056 | This feature is internal to the Rust compiler and is not intended for general use. | 3914 | The tracking issue for this feature is: [#81490] |
3915 | |||
3916 | [#81490]: https://github.com/rust-lang/rust/issues/81490 | ||
4057 | 3917 | ||
4058 | ------------------------ | 3918 | ------------------------ |
3919 | |||
3920 | The `native_link_modifiers_verbatim` feature allows you to use the `verbatim` modifier. | ||
3921 | |||
3922 | `+verbatim` means that rustc itself won't add any target-specified library prefixes or suffixes (like `lib` or `.a`) to the library name, and will try its best to ask for the same thing from the linker. | ||
3923 | |||
3924 | For `ld`-like linkers rustc will use the `-l:filename` syntax (note the colon) when passing the library, so the linker won't add any prefixes or suffixes as well. | ||
3925 | See [`-l namespec`](https://sourceware.org/binutils/docs/ld/Options.html) in ld documentation for more details. | ||
3926 | For linkers not supporting any verbatim modifiers (e.g. `link.exe` or `ld64`) the library name will be passed as is. | ||
3927 | |||
3928 | The default for this modifier is `-verbatim`. | ||
3929 | |||
3930 | This RFC changes the behavior of `raw-dylib` linking kind specified by [RFC 2627](https://github.com/rust-lang/rfcs/pull/2627). The `.dll` suffix (or other target-specified suffixes for other targets) is now added automatically. | ||
3931 | If your DLL doesn't have the `.dll` suffix, it can be specified with `+verbatim`. | ||
4059 | "##, | 3932 | "##, |
4060 | }, | 3933 | }, |
4061 | LintCompletion { | 3934 | Lint { |
4062 | label: "sort_internals", | 3935 | label: "native_link_modifiers_whole_archive", |
4063 | description: r##"# `sort_internals` | 3936 | description: r##"# `native_link_modifiers_whole_archive` |
4064 | 3937 | ||
4065 | This feature is internal to the Rust compiler and is not intended for general use. | 3938 | The tracking issue for this feature is: [#81490] |
3939 | |||
3940 | [#81490]: https://github.com/rust-lang/rust/issues/81490 | ||
4066 | 3941 | ||
4067 | ------------------------ | 3942 | ------------------------ |
3943 | |||
3944 | The `native_link_modifiers_whole_archive` feature allows you to use the `whole-archive` modifier. | ||
3945 | |||
3946 | Only compatible with the `static` linking kind. Using any other kind will result in a compiler error. | ||
3947 | |||
3948 | `+whole-archive` means that the static library is linked as a whole archive without throwing any object files away. | ||
3949 | |||
3950 | This modifier translates to `--whole-archive` for `ld`-like linkers, to `/WHOLEARCHIVE` for `link.exe`, and to `-force_load` for `ld64`. | ||
3951 | The modifier does nothing for linkers that don't support it. | ||
3952 | |||
3953 | The default for this modifier is `-whole-archive`. | ||
4068 | "##, | 3954 | "##, |
4069 | }, | 3955 | }, |
4070 | LintCompletion { | 3956 | Lint { |
4071 | label: "windows_net", | 3957 | label: "negative_impls", |
4072 | description: r##"# `windows_net` | 3958 | description: r##"# `negative_impls` |
4073 | 3959 | ||
4074 | This feature is internal to the Rust compiler and is not intended for general use. | 3960 | The tracking issue for this feature is [#68318]. |
4075 | 3961 | ||
4076 | ------------------------ | 3962 | [#68318]: https://github.com/rust-lang/rust/issues/68318 |
3963 | |||
3964 | ---- | ||
3965 | |||
3966 | With the feature gate `negative_impls`, you can write negative impls as well as positive ones: | ||
3967 | |||
3968 | ```rust | ||
3969 | #![feature(negative_impls)] | ||
3970 | trait DerefMut { } | ||
3971 | impl<T: ?Sized> !DerefMut for &T { } | ||
3972 | ``` | ||
3973 | |||
3974 | Negative impls indicate a semver guarantee that the given trait will not be implemented for the given types. Negative impls play an additional purpose for auto traits, described below. | ||
3975 | |||
3976 | Negative impls have the following characteristics: | ||
3977 | |||
3978 | * They do not have any items. | ||
3979 | * They must obey the orphan rules as if they were a positive impl. | ||
3980 | * They cannot "overlap" with any positive impls. | ||
3981 | |||
3982 | ## Semver interaction | ||
3983 | |||
3984 | It is a breaking change to remove a negative impl. Negative impls are a commitment not to implement the given trait for the named types. | ||
3985 | |||
3986 | ## Orphan and overlap rules | ||
3987 | |||
3988 | Negative impls must obey the same orphan rules as a positive impl. This implies you cannot add a negative impl for types defined in upstream crates and so forth. | ||
3989 | |||
3990 | Similarly, negative impls cannot overlap with positive impls, again using the same "overlap" check that we ordinarily use to determine if two impls overlap. (Note that positive impls typically cannot overlap with one another either, except as permitted by specialization.) | ||
3991 | |||
3992 | ## Interaction with auto traits | ||
3993 | |||
3994 | Declaring a negative impl `impl !SomeAutoTrait for SomeType` for an | ||
3995 | auto-trait serves two purposes: | ||
3996 | |||
3997 | * as with any trait, it declares that `SomeType` will never implement `SomeAutoTrait`; | ||
3998 | * it disables the automatic `SomeType: SomeAutoTrait` impl that would otherwise have been generated. | ||
3999 | |||
4000 | Note that, at present, there is no way to indicate that a given type | ||
4001 | does not implement an auto trait *but that it may do so in the | ||
4002 | future*. For ordinary types, this is done by simply not declaring any | ||
4003 | impl at all, but that is not an option for auto traits. A workaround | ||
4004 | is that one could embed a marker type as one of the fields, where the | ||
4005 | marker type is `!AutoTrait`. | ||
4006 | |||
4007 | ## Immediate uses | ||
4008 | |||
4009 | Negative impls are used to declare that `&T: !DerefMut` and `&mut T: !Clone`, as required to fix the soundness of `Pin` described in [#66544](https://github.com/rust-lang/rust/issues/66544). | ||
4010 | |||
4011 | This serves two purposes: | ||
4012 | |||
4013 | * For proving the correctness of unsafe code, we can use that impl as evidence that no `DerefMut` or `Clone` impl exists. | ||
4014 | * It prevents downstream crates from creating such impls. | ||
4077 | "##, | 4015 | "##, |
4078 | }, | 4016 | }, |
4079 | LintCompletion { | 4017 | Lint { |
4080 | label: "c_variadic", | 4018 | label: "no_coverage", |
4081 | description: r##"# `c_variadic` | 4019 | description: r##"# `no_coverage` |
4082 | 4020 | ||
4083 | The tracking issue for this feature is: [#44930] | 4021 | The tracking issue for this feature is: [#84605] |
4084 | 4022 | ||
4085 | [#44930]: https://github.com/rust-lang/rust/issues/44930 | 4023 | [#84605]: https://github.com/rust-lang/rust/issues/84605 |
4024 | |||
4025 | --- | ||
4026 | |||
4027 | The `no_coverage` attribute can be used to selectively disable coverage | ||
4028 | instrumentation in an annotated function. This might be useful to: | ||
4029 | |||
4030 | - Avoid instrumentation overhead in a performance critical function | ||
4031 | - Avoid generating coverage for a function that is not meant to be executed, | ||
4032 | but still target 100% coverage for the rest of the program. | ||
4033 | |||
4034 | ## Example | ||
4035 | |||
4036 | ```rust | ||
4037 | #![feature(no_coverage)] | ||
4038 | |||
4039 | // `foo()` will get coverage instrumentation (by default) | ||
4040 | fn foo() { | ||
4041 | // ... | ||
4042 | } | ||
4043 | |||
4044 | #[no_coverage] | ||
4045 | fn bar() { | ||
4046 | // ... | ||
4047 | } | ||
4048 | ``` | ||
4049 | "##, | ||
4050 | }, | ||
4051 | Lint { | ||
4052 | label: "no_sanitize", | ||
4053 | description: r##"# `no_sanitize` | ||
4054 | |||
4055 | The tracking issue for this feature is: [#39699] | ||
4056 | |||
4057 | [#39699]: https://github.com/rust-lang/rust/issues/39699 | ||
4086 | 4058 | ||
4087 | ------------------------ | 4059 | ------------------------ |
4088 | 4060 | ||
4089 | The `c_variadic` library feature exposes the `VaList` structure, | 4061 | The `no_sanitize` attribute can be used to selectively disable sanitizer |
4090 | Rust's analogue of C's `va_list` type. | 4062 | instrumentation in an annotated function. This might be useful to: avoid |
4063 | instrumentation overhead in a performance critical function, or avoid | ||
4064 | instrumenting code that contains constructs unsupported by given sanitizer. | ||
4065 | |||
4066 | The precise effect of this annotation depends on particular sanitizer in use. | ||
4067 | For example, with `no_sanitize(thread)`, the thread sanitizer will no longer | ||
4068 | instrument non-atomic store / load operations, but it will instrument atomic | ||
4069 | operations to avoid reporting false positives and provide meaning full stack | ||
4070 | traces. | ||
4091 | 4071 | ||
4092 | ## Examples | 4072 | ## Examples |
4093 | 4073 | ||
4094 | ```rust | 4074 | ``` rust |
4095 | #![feature(c_variadic)] | 4075 | #![feature(no_sanitize)] |
4096 | 4076 | ||
4097 | use std::ffi::VaList; | 4077 | #[no_sanitize(address)] |
4078 | fn foo() { | ||
4079 | // ... | ||
4080 | } | ||
4081 | ``` | ||
4082 | "##, | ||
4083 | }, | ||
4084 | Lint { | ||
4085 | label: "plugin", | ||
4086 | description: r##"# `plugin` | ||
4098 | 4087 | ||
4099 | pub unsafe extern "C" fn vadd(n: usize, mut args: VaList) -> usize { | 4088 | The tracking issue for this feature is: [#29597] |
4100 | let mut sum = 0; | 4089 | |
4101 | for _ in 0..n { | 4090 | [#29597]: https://github.com/rust-lang/rust/issues/29597 |
4102 | sum += args.arg::<usize>(); | 4091 | |
4092 | |||
4093 | This feature is part of "compiler plugins." It will often be used with the | ||
4094 | [`plugin_registrar`] and `rustc_private` features. | ||
4095 | |||
4096 | [`plugin_registrar`]: plugin-registrar.md | ||
4097 | |||
4098 | ------------------------ | ||
4099 | |||
4100 | `rustc` can load compiler plugins, which are user-provided libraries that | ||
4101 | extend the compiler's behavior with new lint checks, etc. | ||
4102 | |||
4103 | A plugin is a dynamic library crate with a designated *registrar* function that | ||
4104 | registers extensions with `rustc`. Other crates can load these extensions using | ||
4105 | the crate attribute `#![plugin(...)]`. See the | ||
4106 | `rustc_driver::plugin` documentation for more about the | ||
4107 | mechanics of defining and loading a plugin. | ||
4108 | |||
4109 | In the vast majority of cases, a plugin should *only* be used through | ||
4110 | `#![plugin]` and not through an `extern crate` item. Linking a plugin would | ||
4111 | pull in all of librustc_ast and librustc as dependencies of your crate. This is | ||
4112 | generally unwanted unless you are building another plugin. | ||
4113 | |||
4114 | The usual practice is to put compiler plugins in their own crate, separate from | ||
4115 | any `macro_rules!` macros or ordinary Rust code meant to be used by consumers | ||
4116 | of a library. | ||
4117 | |||
4118 | # Lint plugins | ||
4119 | |||
4120 | Plugins can extend [Rust's lint | ||
4121 | infrastructure](../../reference/attributes/diagnostics.md#lint-check-attributes) with | ||
4122 | additional checks for code style, safety, etc. Now let's write a plugin | ||
4123 | [`lint-plugin-test.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui-fulldeps/auxiliary/lint-plugin-test.rs) | ||
4124 | that warns about any item named `lintme`. | ||
4125 | |||
4126 | ```rust,ignore (requires-stage-2) | ||
4127 | #![feature(plugin_registrar)] | ||
4128 | #![feature(box_syntax, rustc_private)] | ||
4129 | |||
4130 | extern crate rustc_ast; | ||
4131 | |||
4132 | // Load rustc as a plugin to get macros | ||
4133 | extern crate rustc_driver; | ||
4134 | #[macro_use] | ||
4135 | extern crate rustc_lint; | ||
4136 | #[macro_use] | ||
4137 | extern crate rustc_session; | ||
4138 | |||
4139 | use rustc_driver::plugin::Registry; | ||
4140 | use rustc_lint::{EarlyContext, EarlyLintPass, LintArray, LintContext, LintPass}; | ||
4141 | use rustc_ast::ast; | ||
4142 | declare_lint!(TEST_LINT, Warn, "Warn about items named 'lintme'"); | ||
4143 | |||
4144 | declare_lint_pass!(Pass => [TEST_LINT]); | ||
4145 | |||
4146 | impl EarlyLintPass for Pass { | ||
4147 | fn check_item(&mut self, cx: &EarlyContext, it: &ast::Item) { | ||
4148 | if it.ident.name.as_str() == "lintme" { | ||
4149 | cx.lint(TEST_LINT, |lint| { | ||
4150 | lint.build("item is named 'lintme'").set_span(it.span).emit() | ||
4151 | }); | ||
4152 | } | ||
4103 | } | 4153 | } |
4104 | sum | ||
4105 | } | 4154 | } |
4155 | |||
4156 | #[plugin_registrar] | ||
4157 | pub fn plugin_registrar(reg: &mut Registry) { | ||
4158 | reg.lint_store.register_lints(&[&TEST_LINT]); | ||
4159 | reg.lint_store.register_early_pass(|| box Pass); | ||
4160 | } | ||
4161 | ``` | ||
4162 | |||
4163 | Then code like | ||
4164 | |||
4165 | ```rust,ignore (requires-plugin) | ||
4166 | #![feature(plugin)] | ||
4167 | #![plugin(lint_plugin_test)] | ||
4168 | |||
4169 | fn lintme() { } | ||
4170 | ``` | ||
4171 | |||
4172 | will produce a compiler warning: | ||
4173 | |||
4174 | ```txt | ||
4175 | foo.rs:4:1: 4:16 warning: item is named 'lintme', #[warn(test_lint)] on by default | ||
4176 | foo.rs:4 fn lintme() { } | ||
4177 | ^~~~~~~~~~~~~~~ | ||
4106 | ``` | 4178 | ``` |
4179 | |||
4180 | The components of a lint plugin are: | ||
4181 | |||
4182 | * one or more `declare_lint!` invocations, which define static `Lint` structs; | ||
4183 | |||
4184 | * a struct holding any state needed by the lint pass (here, none); | ||
4185 | |||
4186 | * a `LintPass` | ||
4187 | implementation defining how to check each syntax element. A single | ||
4188 | `LintPass` may call `span_lint` for several different `Lint`s, but should | ||
4189 | register them all through the `get_lints` method. | ||
4190 | |||
4191 | Lint passes are syntax traversals, but they run at a late stage of compilation | ||
4192 | where type information is available. `rustc`'s [built-in | ||
4193 | lints](https://github.com/rust-lang/rust/blob/master/src/librustc_session/lint/builtin.rs) | ||
4194 | mostly use the same infrastructure as lint plugins, and provide examples of how | ||
4195 | to access type information. | ||
4196 | |||
4197 | Lints defined by plugins are controlled by the usual [attributes and compiler | ||
4198 | flags](../../reference/attributes/diagnostics.md#lint-check-attributes), e.g. | ||
4199 | `#[allow(test_lint)]` or `-A test-lint`. These identifiers are derived from the | ||
4200 | first argument to `declare_lint!`, with appropriate case and punctuation | ||
4201 | conversion. | ||
4202 | |||
4203 | You can run `rustc -W help foo.rs` to see a list of lints known to `rustc`, | ||
4204 | including those provided by plugins loaded by `foo.rs`. | ||
4107 | "##, | 4205 | "##, |
4108 | }, | 4206 | }, |
4109 | LintCompletion { | 4207 | Lint { |
4110 | label: "core_private_diy_float", | 4208 | label: "plugin_registrar", |
4111 | description: r##"# `core_private_diy_float` | 4209 | description: r##"# `plugin_registrar` |
4112 | 4210 | ||
4113 | This feature is internal to the Rust compiler and is not intended for general use. | 4211 | The tracking issue for this feature is: [#29597] |
4212 | |||
4213 | [#29597]: https://github.com/rust-lang/rust/issues/29597 | ||
4214 | |||
4215 | This feature is part of "compiler plugins." It will often be used with the | ||
4216 | [`plugin`] and `rustc_private` features as well. For more details, see | ||
4217 | their docs. | ||
4218 | |||
4219 | [`plugin`]: plugin.md | ||
4114 | 4220 | ||
4115 | ------------------------ | 4221 | ------------------------ |
4116 | "##, | 4222 | "##, |
4117 | }, | 4223 | }, |
4118 | LintCompletion { | 4224 | Lint { |
4119 | label: "profiler_runtime_lib", | 4225 | label: "print_internals", |
4120 | description: r##"# `profiler_runtime_lib` | 4226 | description: r##"# `print_internals` |
4121 | 4227 | ||
4122 | This feature is internal to the Rust compiler and is not intended for general use. | 4228 | This feature is internal to the Rust compiler and is not intended for general use. |
4123 | 4229 | ||
4124 | ------------------------ | 4230 | ------------------------ |
4125 | "##, | 4231 | "##, |
4126 | }, | 4232 | }, |
4127 | LintCompletion { | 4233 | Lint { |
4128 | label: "thread_local_internals", | 4234 | label: "profiler_runtime", |
4129 | description: r##"# `thread_local_internals` | 4235 | description: r##"# `profiler_runtime` |
4130 | 4236 | ||
4131 | This feature is internal to the Rust compiler and is not intended for general use. | 4237 | The tracking issue for this feature is: [#42524](https://github.com/rust-lang/rust/issues/42524). |
4132 | 4238 | ||
4133 | ------------------------ | 4239 | ------------------------ |
4134 | "##, | 4240 | "##, |
4135 | }, | 4241 | }, |
4136 | LintCompletion { | 4242 | Lint { |
4137 | label: "int_error_internals", | 4243 | label: "profiler_runtime_lib", |
4138 | description: r##"# `int_error_internals` | 4244 | description: r##"# `profiler_runtime_lib` |
4139 | 4245 | ||
4140 | This feature is internal to the Rust compiler and is not intended for general use. | 4246 | This feature is internal to the Rust compiler and is not intended for general use. |
4141 | 4247 | ||
4142 | ------------------------ | 4248 | ------------------------ |
4143 | "##, | 4249 | "##, |
4144 | }, | 4250 | }, |
4145 | LintCompletion { | 4251 | Lint { |
4146 | label: "windows_stdio", | 4252 | label: "repr128", |
4147 | description: r##"# `windows_stdio` | 4253 | description: r##"# `repr128` |
4148 | 4254 | ||
4149 | This feature is internal to the Rust compiler and is not intended for general use. | 4255 | The tracking issue for this feature is: [#56071] |
4256 | |||
4257 | [#56071]: https://github.com/rust-lang/rust/issues/56071 | ||
4150 | 4258 | ||
4151 | ------------------------ | 4259 | ------------------------ |
4260 | |||
4261 | The `repr128` feature adds support for `#[repr(u128)]` on `enum`s. | ||
4262 | |||
4263 | ```rust | ||
4264 | #![feature(repr128)] | ||
4265 | |||
4266 | #[repr(u128)] | ||
4267 | enum Foo { | ||
4268 | Bar(u64), | ||
4269 | } | ||
4270 | ``` | ||
4152 | "##, | 4271 | "##, |
4153 | }, | 4272 | }, |
4154 | LintCompletion { | 4273 | Lint { |
4155 | label: "fmt_internals", | 4274 | label: "rt", |
4156 | description: r##"# `fmt_internals` | 4275 | description: r##"# `rt` |
4157 | 4276 | ||
4158 | This feature is internal to the Rust compiler and is not intended for general use. | 4277 | This feature is internal to the Rust compiler and is not intended for general use. |
4159 | 4278 | ||
4160 | ------------------------ | 4279 | ------------------------ |
4161 | "##, | 4280 | "##, |
4162 | }, | 4281 | }, |
4163 | LintCompletion { | 4282 | Lint { |
4164 | label: "fd_read", | 4283 | label: "rustc_attrs", |
4165 | description: r##"# `fd_read` | 4284 | description: r##"# `rustc_attrs` |
4285 | |||
4286 | This feature has no tracking issue, and is therefore internal to | ||
4287 | the compiler, not being intended for general use. | ||
4288 | |||
4289 | Note: `rustc_attrs` enables many rustc-internal attributes and this page | ||
4290 | only discuss a few of them. | ||
4291 | |||
4292 | ------------------------ | ||
4293 | |||
4294 | The `rustc_attrs` feature allows debugging rustc type layouts by using | ||
4295 | `#[rustc_layout(...)]` to debug layout at compile time (it even works | ||
4296 | with `cargo check`) as an alternative to `rustc -Z print-type-sizes` | ||
4297 | that is way more verbose. | ||
4298 | |||
4299 | Options provided by `#[rustc_layout(...)]` are `debug`, `size`, `align`, | ||
4300 | `abi`. Note that it only works on sized types without generics. | ||
4301 | |||
4302 | ## Examples | ||
4303 | |||
4304 | ```rust,compile_fail | ||
4305 | #![feature(rustc_attrs)] | ||
4306 | |||
4307 | #[rustc_layout(abi, size)] | ||
4308 | pub enum X { | ||
4309 | Y(u8, u8, u8), | ||
4310 | Z(isize), | ||
4311 | } | ||
4312 | ``` | ||
4313 | |||
4314 | When that is compiled, the compiler will error with something like | ||
4315 | |||
4316 | ```text | ||
4317 | error: abi: Aggregate { sized: true } | ||
4318 | --> src/lib.rs:4:1 | ||
4319 | | | ||
4320 | 4 | / pub enum T { | ||
4321 | 5 | | Y(u8, u8, u8), | ||
4322 | 6 | | Z(isize), | ||
4323 | 7 | | } | ||
4324 | | |_^ | ||
4325 | |||
4326 | error: size: Size { raw: 16 } | ||
4327 | --> src/lib.rs:4:1 | ||
4328 | | | ||
4329 | 4 | / pub enum T { | ||
4330 | 5 | | Y(u8, u8, u8), | ||
4331 | 6 | | Z(isize), | ||
4332 | 7 | | } | ||
4333 | | |_^ | ||
4334 | |||
4335 | error: aborting due to 2 previous errors | ||
4336 | ``` | ||
4337 | "##, | ||
4338 | }, | ||
4339 | Lint { | ||
4340 | label: "sort_internals", | ||
4341 | description: r##"# `sort_internals` | ||
4166 | 4342 | ||
4167 | This feature is internal to the Rust compiler and is not intended for general use. | 4343 | This feature is internal to the Rust compiler and is not intended for general use. |
4168 | 4344 | ||
4169 | ------------------------ | 4345 | ------------------------ |
4170 | "##, | 4346 | "##, |
4171 | }, | 4347 | }, |
4172 | LintCompletion { | 4348 | Lint { |
4173 | label: "str_internals", | 4349 | label: "str_internals", |
4174 | description: r##"# `str_internals` | 4350 | description: r##"# `str_internals` |
4175 | 4351 | ||
@@ -4178,7 +4354,7 @@ This feature is internal to the Rust compiler and is not intended for general us | |||
4178 | ------------------------ | 4354 | ------------------------ |
4179 | "##, | 4355 | "##, |
4180 | }, | 4356 | }, |
4181 | LintCompletion { | 4357 | Lint { |
4182 | label: "test", | 4358 | label: "test", |
4183 | description: r##"# `test` | 4359 | description: r##"# `test` |
4184 | 4360 | ||
@@ -4340,101 +4516,218 @@ However, the optimizer can still modify a testcase in an undesirable manner | |||
4340 | even when using either of the above. | 4516 | even when using either of the above. |
4341 | "##, | 4517 | "##, |
4342 | }, | 4518 | }, |
4343 | LintCompletion { | 4519 | Lint { |
4344 | label: "windows_c", | 4520 | label: "thread_local_internals", |
4345 | description: r##"# `windows_c` | 4521 | description: r##"# `thread_local_internals` |
4346 | 4522 | ||
4347 | This feature is internal to the Rust compiler and is not intended for general use. | 4523 | This feature is internal to the Rust compiler and is not intended for general use. |
4348 | 4524 | ||
4349 | ------------------------ | 4525 | ------------------------ |
4350 | "##, | 4526 | "##, |
4351 | }, | 4527 | }, |
4352 | LintCompletion { | 4528 | Lint { |
4353 | label: "dec2flt", | 4529 | label: "trace_macros", |
4354 | description: r##"# `dec2flt` | 4530 | description: r##"# `trace_macros` |
4355 | 4531 | ||
4356 | This feature is internal to the Rust compiler and is not intended for general use. | 4532 | The tracking issue for this feature is [#29598]. |
4533 | |||
4534 | [#29598]: https://github.com/rust-lang/rust/issues/29598 | ||
4357 | 4535 | ||
4358 | ------------------------ | 4536 | ------------------------ |
4359 | "##, | ||
4360 | }, | ||
4361 | LintCompletion { | ||
4362 | label: "derive_clone_copy", | ||
4363 | description: r##"# `derive_clone_copy` | ||
4364 | 4537 | ||
4365 | This feature is internal to the Rust compiler and is not intended for general use. | 4538 | With `trace_macros` you can trace the expansion of macros in your code. |
4366 | 4539 | ||
4367 | ------------------------ | 4540 | ## Examples |
4368 | "##, | ||
4369 | }, | ||
4370 | LintCompletion { | ||
4371 | label: "allocator_api", | ||
4372 | description: r##"# `allocator_api` | ||
4373 | 4541 | ||
4374 | The tracking issue for this feature is [#32838] | 4542 | ```rust |
4543 | #![feature(trace_macros)] | ||
4375 | 4544 | ||
4376 | [#32838]: https://github.com/rust-lang/rust/issues/32838 | 4545 | fn main() { |
4546 | trace_macros!(true); | ||
4547 | println!("Hello, Rust!"); | ||
4548 | trace_macros!(false); | ||
4549 | } | ||
4550 | ``` | ||
4377 | 4551 | ||
4378 | ------------------------ | 4552 | The `cargo build` output: |
4379 | 4553 | ||
4380 | Sometimes you want the memory for one collection to use a different | 4554 | ```txt |
4381 | allocator than the memory for another collection. In this case, | 4555 | note: trace_macro |
4382 | replacing the global allocator is not a workable option. Instead, | 4556 | --> src/main.rs:5:5 |
4383 | you need to pass in an instance of an `AllocRef` to each collection | 4557 | | |
4384 | for which you want a custom allocator. | 4558 | 5 | println!("Hello, Rust!"); |
4559 | | ^^^^^^^^^^^^^^^^^^^^^^^^^ | ||
4560 | | | ||
4561 | = note: expanding `println! { "Hello, Rust!" }` | ||
4562 | = note: to `print ! ( concat ! ( "Hello, Rust!" , "\n" ) )` | ||
4563 | = note: expanding `print! { concat ! ( "Hello, Rust!" , "\n" ) }` | ||
4564 | = note: to `$crate :: io :: _print ( format_args ! ( concat ! ( "Hello, Rust!" , "\n" ) ) | ||
4565 | )` | ||
4385 | 4566 | ||
4386 | TBD | 4567 | Finished dev [unoptimized + debuginfo] target(s) in 0.60 secs |
4568 | ``` | ||
4387 | "##, | 4569 | "##, |
4388 | }, | 4570 | }, |
4389 | LintCompletion { | 4571 | Lint { |
4390 | label: "core_panic", | 4572 | label: "trait_alias", |
4391 | description: r##"# `core_panic` | 4573 | description: r##"# `trait_alias` |
4392 | 4574 | ||
4393 | This feature is internal to the Rust compiler and is not intended for general use. | 4575 | The tracking issue for this feature is: [#41517] |
4576 | |||
4577 | [#41517]: https://github.com/rust-lang/rust/issues/41517 | ||
4394 | 4578 | ||
4395 | ------------------------ | 4579 | ------------------------ |
4580 | |||
4581 | The `trait_alias` feature adds support for trait aliases. These allow aliases | ||
4582 | to be created for one or more traits (currently just a single regular trait plus | ||
4583 | any number of auto-traits), and used wherever traits would normally be used as | ||
4584 | either bounds or trait objects. | ||
4585 | |||
4586 | ```rust | ||
4587 | #![feature(trait_alias)] | ||
4588 | |||
4589 | trait Foo = std::fmt::Debug + Send; | ||
4590 | trait Bar = Foo + Sync; | ||
4591 | |||
4592 | // Use trait alias as bound on type parameter. | ||
4593 | fn foo<T: Foo>(v: &T) { | ||
4594 | println!("{:?}", v); | ||
4595 | } | ||
4596 | |||
4597 | pub fn main() { | ||
4598 | foo(&1); | ||
4599 | |||
4600 | // Use trait alias for trait objects. | ||
4601 | let a: &Bar = &123; | ||
4602 | println!("{:?}", a); | ||
4603 | let b = Box::new(456) as Box<dyn Foo>; | ||
4604 | println!("{:?}", b); | ||
4605 | } | ||
4606 | ``` | ||
4396 | "##, | 4607 | "##, |
4397 | }, | 4608 | }, |
4398 | LintCompletion { | 4609 | Lint { |
4399 | label: "fn_traits", | 4610 | label: "transparent_unions", |
4400 | description: r##"# `fn_traits` | 4611 | description: r##"# `transparent_unions` |
4401 | |||
4402 | The tracking issue for this feature is [#29625] | ||
4403 | 4612 | ||
4404 | See Also: [`unboxed_closures`](../language-features/unboxed-closures.md) | 4613 | The tracking issue for this feature is [#60405] |
4405 | 4614 | ||
4406 | [#29625]: https://github.com/rust-lang/rust/issues/29625 | 4615 | [#60405]: https://github.com/rust-lang/rust/issues/60405 |
4407 | 4616 | ||
4408 | ---- | 4617 | ---- |
4409 | 4618 | ||
4410 | The `fn_traits` feature allows for implementation of the [`Fn*`] traits | 4619 | The `transparent_unions` feature allows you mark `union`s as |
4411 | for creating custom closure-like types. | 4620 | `#[repr(transparent)]`. A `union` may be `#[repr(transparent)]` in exactly the |
4412 | 4621 | same conditions in which a `struct` may be `#[repr(transparent)]` (generally, | |
4413 | [`Fn*`]: https://doc.rust-lang.org/std/ops/trait.Fn.html | 4622 | this means the `union` must have exactly one non-zero-sized field). Some |
4623 | concrete illustrations follow. | ||
4414 | 4624 | ||
4415 | ```rust | 4625 | ```rust |
4416 | #![feature(unboxed_closures)] | 4626 | #![feature(transparent_unions)] |
4417 | #![feature(fn_traits)] | ||
4418 | 4627 | ||
4419 | struct Adder { | 4628 | // This union has the same representation as `f32`. |
4420 | a: u32 | 4629 | #[repr(transparent)] |
4630 | union SingleFieldUnion { | ||
4631 | field: f32, | ||
4421 | } | 4632 | } |
4422 | 4633 | ||
4423 | impl FnOnce<(u32, )> for Adder { | 4634 | // This union has the same representation as `usize`. |
4424 | type Output = u32; | 4635 | #[repr(transparent)] |
4425 | extern "rust-call" fn call_once(self, b: (u32, )) -> Self::Output { | 4636 | union MultiFieldUnion { |
4426 | self.a + b.0 | 4637 | field: usize, |
4427 | } | 4638 | nothing: (), |
4428 | } | 4639 | } |
4640 | ``` | ||
4429 | 4641 | ||
4430 | fn main() { | 4642 | For consistency with transparent `struct`s, `union`s must have exactly one |
4431 | let adder = Adder { a: 3 }; | 4643 | non-zero-sized field. If all fields are zero-sized, the `union` must not be |
4432 | assert_eq!(adder(2), 5); | 4644 | `#[repr(transparent)]`: |
4645 | |||
4646 | ```rust | ||
4647 | #![feature(transparent_unions)] | ||
4648 | |||
4649 | // This (non-transparent) union is already valid in stable Rust: | ||
4650 | pub union GoodUnion { | ||
4651 | pub nothing: (), | ||
4652 | } | ||
4653 | |||
4654 | // Error: transparent union needs exactly one non-zero-sized field, but has 0 | ||
4655 | // #[repr(transparent)] | ||
4656 | // pub union BadUnion { | ||
4657 | // pub nothing: (), | ||
4658 | // } | ||
4659 | ``` | ||
4660 | |||
4661 | The one exception is if the `union` is generic over `T` and has a field of type | ||
4662 | `T`, it may be `#[repr(transparent)]` even if `T` is a zero-sized type: | ||
4663 | |||
4664 | ```rust | ||
4665 | #![feature(transparent_unions)] | ||
4666 | |||
4667 | // This union has the same representation as `T`. | ||
4668 | #[repr(transparent)] | ||
4669 | pub union GenericUnion<T: Copy> { // Unions with non-`Copy` fields are unstable. | ||
4670 | pub field: T, | ||
4671 | pub nothing: (), | ||
4433 | } | 4672 | } |
4673 | |||
4674 | // This is okay even though `()` is a zero-sized type. | ||
4675 | pub const THIS_IS_OKAY: GenericUnion<()> = GenericUnion { field: () }; | ||
4434 | ``` | 4676 | ``` |
4677 | |||
4678 | Like transarent `struct`s, a transparent `union` of type `U` has the same | ||
4679 | layout, size, and ABI as its single non-ZST field. If it is generic over a type | ||
4680 | `T`, and all its fields are ZSTs except for exactly one field of type `T`, then | ||
4681 | it has the same layout and ABI as `T` (even if `T` is a ZST when monomorphized). | ||
4682 | |||
4683 | Like transparent `struct`s, transparent `union`s are FFI-safe if and only if | ||
4684 | their underlying representation type is also FFI-safe. | ||
4685 | |||
4686 | A `union` may not be eligible for the same nonnull-style optimizations that a | ||
4687 | `struct` or `enum` (with the same fields) are eligible for. Adding | ||
4688 | `#[repr(transparent)]` to `union` does not change this. To give a more concrete | ||
4689 | example, it is unspecified whether `size_of::<T>()` is equal to | ||
4690 | `size_of::<Option<T>>()`, where `T` is a `union` (regardless of whether or not | ||
4691 | it is transparent). The Rust compiler is free to perform this optimization if | ||
4692 | possible, but is not required to, and different compiler versions may differ in | ||
4693 | their application of these optimizations. | ||
4435 | "##, | 4694 | "##, |
4436 | }, | 4695 | }, |
4437 | LintCompletion { | 4696 | Lint { |
4697 | label: "try_blocks", | ||
4698 | description: r##"# `try_blocks` | ||
4699 | |||
4700 | The tracking issue for this feature is: [#31436] | ||
4701 | |||
4702 | [#31436]: https://github.com/rust-lang/rust/issues/31436 | ||
4703 | |||
4704 | ------------------------ | ||
4705 | |||
4706 | The `try_blocks` feature adds support for `try` blocks. A `try` | ||
4707 | block creates a new scope one can use the `?` operator in. | ||
4708 | |||
4709 | ```rust,edition2018 | ||
4710 | #![feature(try_blocks)] | ||
4711 | |||
4712 | use std::num::ParseIntError; | ||
4713 | |||
4714 | let result: Result<i32, ParseIntError> = try { | ||
4715 | "1".parse::<i32>()? | ||
4716 | + "2".parse::<i32>()? | ||
4717 | + "3".parse::<i32>()? | ||
4718 | }; | ||
4719 | assert_eq!(result, Ok(6)); | ||
4720 | |||
4721 | let result: Result<i32, ParseIntError> = try { | ||
4722 | "1".parse::<i32>()? | ||
4723 | + "foo".parse::<i32>()? | ||
4724 | + "3".parse::<i32>()? | ||
4725 | }; | ||
4726 | assert!(result.is_err()); | ||
4727 | ``` | ||
4728 | "##, | ||
4729 | }, | ||
4730 | Lint { | ||
4438 | label: "try_trait", | 4731 | label: "try_trait", |
4439 | description: r##"# `try_trait` | 4732 | description: r##"# `try_trait` |
4440 | 4733 | ||
@@ -4488,27 +4781,284 @@ function (or catch block). Having a distinct error type (as opposed to | |||
4488 | just `()`, or similar) restricts this to where it's semantically meaningful. | 4781 | just `()`, or similar) restricts this to where it's semantically meaningful. |
4489 | "##, | 4782 | "##, |
4490 | }, | 4783 | }, |
4491 | LintCompletion { | 4784 | Lint { |
4492 | label: "rt", | 4785 | label: "unboxed_closures", |
4493 | description: r##"# `rt` | 4786 | description: r##"# `unboxed_closures` |
4787 | |||
4788 | The tracking issue for this feature is [#29625] | ||
4789 | |||
4790 | See Also: [`fn_traits`](../library-features/fn-traits.md) | ||
4791 | |||
4792 | [#29625]: https://github.com/rust-lang/rust/issues/29625 | ||
4793 | |||
4794 | ---- | ||
4795 | |||
4796 | The `unboxed_closures` feature allows you to write functions using the `"rust-call"` ABI, | ||
4797 | required for implementing the [`Fn*`] family of traits. `"rust-call"` functions must have | ||
4798 | exactly one (non self) argument, a tuple representing the argument list. | ||
4799 | |||
4800 | [`Fn*`]: https://doc.rust-lang.org/std/ops/trait.Fn.html | ||
4801 | |||
4802 | ```rust | ||
4803 | #![feature(unboxed_closures)] | ||
4804 | |||
4805 | extern "rust-call" fn add_args(args: (u32, u32)) -> u32 { | ||
4806 | args.0 + args.1 | ||
4807 | } | ||
4808 | |||
4809 | fn main() {} | ||
4810 | ``` | ||
4811 | "##, | ||
4812 | }, | ||
4813 | Lint { | ||
4814 | label: "unsized_locals", | ||
4815 | description: r##"# `unsized_locals` | ||
4816 | |||
4817 | The tracking issue for this feature is: [#48055] | ||
4818 | |||
4819 | [#48055]: https://github.com/rust-lang/rust/issues/48055 | ||
4820 | |||
4821 | ------------------------ | ||
4822 | |||
4823 | This implements [RFC1909]. When turned on, you can have unsized arguments and locals: | ||
4824 | |||
4825 | [RFC1909]: https://github.com/rust-lang/rfcs/blob/master/text/1909-unsized-rvalues.md | ||
4826 | |||
4827 | ```rust | ||
4828 | #![allow(incomplete_features)] | ||
4829 | #![feature(unsized_locals, unsized_fn_params)] | ||
4830 | |||
4831 | use std::any::Any; | ||
4832 | |||
4833 | fn main() { | ||
4834 | let x: Box<dyn Any> = Box::new(42); | ||
4835 | let x: dyn Any = *x; | ||
4836 | // ^ unsized local variable | ||
4837 | // ^^ unsized temporary | ||
4838 | foo(x); | ||
4839 | } | ||
4840 | |||
4841 | fn foo(_: dyn Any) {} | ||
4842 | // ^^^^^^ unsized argument | ||
4843 | ``` | ||
4844 | |||
4845 | The RFC still forbids the following unsized expressions: | ||
4846 | |||
4847 | ```rust,compile_fail | ||
4848 | #![feature(unsized_locals)] | ||
4849 | |||
4850 | use std::any::Any; | ||
4851 | |||
4852 | struct MyStruct<T: ?Sized> { | ||
4853 | content: T, | ||
4854 | } | ||
4855 | |||
4856 | struct MyTupleStruct<T: ?Sized>(T); | ||
4857 | |||
4858 | fn answer() -> Box<dyn Any> { | ||
4859 | Box::new(42) | ||
4860 | } | ||
4861 | |||
4862 | fn main() { | ||
4863 | // You CANNOT have unsized statics. | ||
4864 | static X: dyn Any = *answer(); // ERROR | ||
4865 | const Y: dyn Any = *answer(); // ERROR | ||
4866 | |||
4867 | // You CANNOT have struct initialized unsized. | ||
4868 | MyStruct { content: *answer() }; // ERROR | ||
4869 | MyTupleStruct(*answer()); // ERROR | ||
4870 | (42, *answer()); // ERROR | ||
4871 | |||
4872 | // You CANNOT have unsized return types. | ||
4873 | fn my_function() -> dyn Any { *answer() } // ERROR | ||
4874 | |||
4875 | // You CAN have unsized local variables... | ||
4876 | let mut x: dyn Any = *answer(); // OK | ||
4877 | // ...but you CANNOT reassign to them. | ||
4878 | x = *answer(); // ERROR | ||
4879 | |||
4880 | // You CANNOT even initialize them separately. | ||
4881 | let y: dyn Any; // OK | ||
4882 | y = *answer(); // ERROR | ||
4883 | |||
4884 | // Not mentioned in the RFC, but by-move captured variables are also Sized. | ||
4885 | let x: dyn Any = *answer(); | ||
4886 | (move || { // ERROR | ||
4887 | let y = x; | ||
4888 | })(); | ||
4889 | |||
4890 | // You CAN create a closure with unsized arguments, | ||
4891 | // but you CANNOT call it. | ||
4892 | // This is an implementation detail and may be changed in the future. | ||
4893 | let f = |x: dyn Any| {}; | ||
4894 | f(*answer()); // ERROR | ||
4895 | } | ||
4896 | ``` | ||
4897 | |||
4898 | ## By-value trait objects | ||
4899 | |||
4900 | With this feature, you can have by-value `self` arguments without `Self: Sized` bounds. | ||
4901 | |||
4902 | ```rust | ||
4903 | #![feature(unsized_fn_params)] | ||
4904 | |||
4905 | trait Foo { | ||
4906 | fn foo(self) {} | ||
4907 | } | ||
4908 | |||
4909 | impl<T: ?Sized> Foo for T {} | ||
4910 | |||
4911 | fn main() { | ||
4912 | let slice: Box<[i32]> = Box::new([1, 2, 3]); | ||
4913 | <[i32] as Foo>::foo(*slice); | ||
4914 | } | ||
4915 | ``` | ||
4916 | |||
4917 | And `Foo` will also be object-safe. | ||
4918 | |||
4919 | ```rust | ||
4920 | #![feature(unsized_fn_params)] | ||
4921 | |||
4922 | trait Foo { | ||
4923 | fn foo(self) {} | ||
4924 | } | ||
4925 | |||
4926 | impl<T: ?Sized> Foo for T {} | ||
4927 | |||
4928 | fn main () { | ||
4929 | let slice: Box<dyn Foo> = Box::new([1, 2, 3]); | ||
4930 | // doesn't compile yet | ||
4931 | <dyn Foo as Foo>::foo(*slice); | ||
4932 | } | ||
4933 | ``` | ||
4934 | |||
4935 | One of the objectives of this feature is to allow `Box<dyn FnOnce>`. | ||
4936 | |||
4937 | ## Variable length arrays | ||
4938 | |||
4939 | The RFC also describes an extension to the array literal syntax: `[e; dyn n]`. In the syntax, `n` isn't necessarily a constant expression. The array is dynamically allocated on the stack and has the type of `[T]`, instead of `[T; n]`. | ||
4940 | |||
4941 | ```rust,ignore (not-yet-implemented) | ||
4942 | #![feature(unsized_locals)] | ||
4943 | |||
4944 | fn mergesort<T: Ord>(a: &mut [T]) { | ||
4945 | let mut tmp = [T; dyn a.len()]; | ||
4946 | // ... | ||
4947 | } | ||
4948 | |||
4949 | fn main() { | ||
4950 | let mut a = [3, 1, 5, 6]; | ||
4951 | mergesort(&mut a); | ||
4952 | assert_eq!(a, [1, 3, 5, 6]); | ||
4953 | } | ||
4954 | ``` | ||
4955 | |||
4956 | VLAs are not implemented yet. The syntax isn't final, either. We may need an alternative syntax for Rust 2015 because, in Rust 2015, expressions like `[e; dyn(1)]` would be ambiguous. One possible alternative proposed in the RFC is `[e; n]`: if `n` captures one or more local variables, then it is considered as `[e; dyn n]`. | ||
4957 | |||
4958 | ## Advisory on stack usage | ||
4959 | |||
4960 | It's advised not to casually use the `#![feature(unsized_locals)]` feature. Typical use-cases are: | ||
4961 | |||
4962 | - When you need a by-value trait objects. | ||
4963 | - When you really need a fast allocation of small temporary arrays. | ||
4964 | |||
4965 | Another pitfall is repetitive allocation and temporaries. Currently the compiler simply extends the stack frame every time it encounters an unsized assignment. So for example, the code | ||
4966 | |||
4967 | ```rust | ||
4968 | #![feature(unsized_locals)] | ||
4969 | |||
4970 | fn main() { | ||
4971 | let x: Box<[i32]> = Box::new([1, 2, 3, 4, 5]); | ||
4972 | let _x = {{{{{{{{{{*x}}}}}}}}}}; | ||
4973 | } | ||
4974 | ``` | ||
4975 | |||
4976 | and the code | ||
4977 | |||
4978 | ```rust | ||
4979 | #![feature(unsized_locals)] | ||
4980 | |||
4981 | fn main() { | ||
4982 | for _ in 0..10 { | ||
4983 | let x: Box<[i32]> = Box::new([1, 2, 3, 4, 5]); | ||
4984 | let _x = *x; | ||
4985 | } | ||
4986 | } | ||
4987 | ``` | ||
4988 | |||
4989 | will unnecessarily extend the stack frame. | ||
4990 | "##, | ||
4991 | }, | ||
4992 | Lint { | ||
4993 | label: "unsized_tuple_coercion", | ||
4994 | description: r##"# `unsized_tuple_coercion` | ||
4995 | |||
4996 | The tracking issue for this feature is: [#42877] | ||
4997 | |||
4998 | [#42877]: https://github.com/rust-lang/rust/issues/42877 | ||
4999 | |||
5000 | ------------------------ | ||
5001 | |||
5002 | This is a part of [RFC0401]. According to the RFC, there should be an implementation like this: | ||
5003 | |||
5004 | ```rust,ignore (partial-example) | ||
5005 | impl<..., T, U: ?Sized> Unsized<(..., U)> for (..., T) where T: Unsized<U> {} | ||
5006 | ``` | ||
5007 | |||
5008 | This implementation is currently gated behind `#[feature(unsized_tuple_coercion)]` to avoid insta-stability. Therefore you can use it like this: | ||
5009 | |||
5010 | ```rust | ||
5011 | #![feature(unsized_tuple_coercion)] | ||
5012 | |||
5013 | fn main() { | ||
5014 | let x : ([i32; 3], [i32; 3]) = ([1, 2, 3], [4, 5, 6]); | ||
5015 | let y : &([i32; 3], [i32]) = &x; | ||
5016 | assert_eq!(y.1[0], 4); | ||
5017 | } | ||
5018 | ``` | ||
5019 | |||
5020 | [RFC0401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md | ||
5021 | "##, | ||
5022 | }, | ||
5023 | Lint { | ||
5024 | label: "update_panic_count", | ||
5025 | description: r##"# `update_panic_count` | ||
4494 | 5026 | ||
4495 | This feature is internal to the Rust compiler and is not intended for general use. | 5027 | This feature is internal to the Rust compiler and is not intended for general use. |
4496 | 5028 | ||
4497 | ------------------------ | 5029 | ------------------------ |
4498 | "##, | 5030 | "##, |
4499 | }, | 5031 | }, |
4500 | LintCompletion { | 5032 | Lint { |
4501 | label: "fd", | 5033 | label: "windows_c", |
4502 | description: r##"# `fd` | 5034 | description: r##"# `windows_c` |
4503 | 5035 | ||
4504 | This feature is internal to the Rust compiler and is not intended for general use. | 5036 | This feature is internal to the Rust compiler and is not intended for general use. |
4505 | 5037 | ||
4506 | ------------------------ | 5038 | ------------------------ |
4507 | "##, | 5039 | "##, |
4508 | }, | 5040 | }, |
4509 | LintCompletion { | 5041 | Lint { |
4510 | label: "libstd_thread_internals", | 5042 | label: "windows_handle", |
4511 | description: r##"# `libstd_thread_internals` | 5043 | description: r##"# `windows_handle` |
5044 | |||
5045 | This feature is internal to the Rust compiler and is not intended for general use. | ||
5046 | |||
5047 | ------------------------ | ||
5048 | "##, | ||
5049 | }, | ||
5050 | Lint { | ||
5051 | label: "windows_net", | ||
5052 | description: r##"# `windows_net` | ||
5053 | |||
5054 | This feature is internal to the Rust compiler and is not intended for general use. | ||
5055 | |||
5056 | ------------------------ | ||
5057 | "##, | ||
5058 | }, | ||
5059 | Lint { | ||
5060 | label: "windows_stdio", | ||
5061 | description: r##"# `windows_stdio` | ||
4512 | 5062 | ||
4513 | This feature is internal to the Rust compiler and is not intended for general use. | 5063 | This feature is internal to the Rust compiler and is not intended for general use. |
4514 | 5064 | ||
@@ -4517,1863 +5067,1851 @@ This feature is internal to the Rust compiler and is not intended for general us | |||
4517 | }, | 5067 | }, |
4518 | ]; | 5068 | ]; |
4519 | 5069 | ||
4520 | pub(super) const CLIPPY_LINTS: &[LintCompletion] = &[ | 5070 | pub const CLIPPY_LINTS: &[Lint] = &[ |
4521 | LintCompletion { | 5071 | Lint { |
4522 | label: "clippy::absurd_extreme_comparisons", | 5072 | label: "clippy::absurd_extreme_comparisons", |
4523 | description: r##"Checks for comparisons where one side of the relation is\neither the minimum or maximum value for its type and warns if it involves a\ncase that is always true or always false. Only integer and boolean types are\nchecked."##, | 5073 | description: r##"Checks for comparisons where one side of the relation is\neither the minimum or maximum value for its type and warns if it involves a\ncase that is always true or always false. Only integer and boolean types are\nchecked."##, |
4524 | }, | 5074 | }, |
4525 | LintCompletion { | 5075 | Lint { |
4526 | label: "clippy::almost_swapped", | 5076 | label: "clippy::almost_swapped", |
4527 | description: r##"Checks for `foo = bar; bar = foo` sequences."##, | 5077 | description: r##"Checks for `foo = bar; bar = foo` sequences."##, |
4528 | }, | 5078 | }, |
4529 | LintCompletion { | 5079 | Lint { |
4530 | label: "clippy::approx_constant", | 5080 | label: "clippy::approx_constant", |
4531 | description: r##"Checks for floating point literals that approximate\nconstants which are defined in\n[`std::f32::consts`](https://doc.rust-lang.org/stable/std/f32/consts/#constants)\nor\n[`std::f64::consts`](https://doc.rust-lang.org/stable/std/f64/consts/#constants),\nrespectively, suggesting to use the predefined constant."##, | 5081 | description: r##"Checks for floating point literals that approximate\nconstants which are defined in\n[`std::f32::consts`](https://doc.rust-lang.org/stable/std/f32/consts/#constants)\nor\n[`std::f64::consts`](https://doc.rust-lang.org/stable/std/f64/consts/#constants),\nrespectively, suggesting to use the predefined constant."##, |
4532 | }, | 5082 | }, |
4533 | LintCompletion { | 5083 | Lint { |
4534 | label: "clippy::as_conversions", | 5084 | label: "clippy::as_conversions", |
4535 | description: r##"Checks for usage of `as` conversions.\n\nNote that this lint is specialized in linting *every single* use of `as`\nregardless of whether good alternatives exist or not.\nIf you want more precise lints for `as`, please consider using these separate lints:\n`unnecessary_cast`, `cast_lossless/possible_truncation/possible_wrap/precision_loss/sign_loss`,\n`fn_to_numeric_cast(_with_truncation)`, `char_lit_as_u8`, `ref_to_mut` and `ptr_as_ptr`.\nThere is a good explanation the reason why this lint should work in this way and how it is useful\n[in this issue](https://github.com/rust-lang/rust-clippy/issues/5122)."##, | 5085 | description: r##"Checks for usage of `as` conversions.\n\nNote that this lint is specialized in linting *every single* use of `as`\nregardless of whether good alternatives exist or not.\nIf you want more precise lints for `as`, please consider using these separate lints:\n`unnecessary_cast`, `cast_lossless/possible_truncation/possible_wrap/precision_loss/sign_loss`,\n`fn_to_numeric_cast(_with_truncation)`, `char_lit_as_u8`, `ref_to_mut` and `ptr_as_ptr`.\nThere is a good explanation the reason why this lint should work in this way and how it is useful\n[in this issue](https://github.com/rust-lang/rust-clippy/issues/5122)."##, |
4536 | }, | 5086 | }, |
4537 | LintCompletion { | 5087 | Lint { |
4538 | label: "clippy::assertions_on_constants", | 5088 | label: "clippy::assertions_on_constants", |
4539 | description: r##"Checks for `assert!(true)` and `assert!(false)` calls."##, | 5089 | description: r##"Checks for `assert!(true)` and `assert!(false)` calls."##, |
4540 | }, | 5090 | }, |
4541 | LintCompletion { | 5091 | Lint { |
4542 | label: "clippy::assign_op_pattern", | 5092 | label: "clippy::assign_op_pattern", |
4543 | description: r##"Checks for `a = a op b` or `a = b commutative_op a`\npatterns."##, | 5093 | description: r##"Checks for `a = a op b` or `a = b commutative_op a`\npatterns."##, |
4544 | }, | 5094 | }, |
4545 | LintCompletion { | 5095 | Lint { |
4546 | label: "clippy::assign_ops", | 5096 | label: "clippy::assign_ops", |
4547 | description: r##"Nothing. This lint has been deprecated."##, | 5097 | description: r##"Nothing. This lint has been deprecated."##, |
4548 | }, | 5098 | }, |
4549 | LintCompletion { | 5099 | Lint { |
4550 | label: "clippy::async_yields_async", | 5100 | label: "clippy::async_yields_async", |
4551 | description: r##"Checks for async blocks that yield values of types\nthat can themselves be awaited."##, | 5101 | description: r##"Checks for async blocks that yield values of types\nthat can themselves be awaited."##, |
4552 | }, | 5102 | }, |
4553 | LintCompletion { | 5103 | Lint { |
4554 | label: "clippy::await_holding_lock", | 5104 | label: "clippy::await_holding_lock", |
4555 | description: r##"Checks for calls to await while holding a\nnon-async-aware MutexGuard."##, | 5105 | description: r##"Checks for calls to await while holding a\nnon-async-aware MutexGuard."##, |
4556 | }, | 5106 | }, |
4557 | LintCompletion { | 5107 | Lint { |
4558 | label: "clippy::await_holding_refcell_ref", | 5108 | label: "clippy::await_holding_refcell_ref", |
4559 | description: r##"Checks for calls to await while holding a\n`RefCell` `Ref` or `RefMut`."##, | 5109 | description: r##"Checks for calls to await while holding a\n`RefCell` `Ref` or `RefMut`."##, |
4560 | }, | 5110 | }, |
4561 | LintCompletion { | 5111 | Lint { |
4562 | label: "clippy::bad_bit_mask", | 5112 | label: "clippy::bad_bit_mask", |
4563 | description: r##"Checks for incompatible bit masks in comparisons.\n\nThe formula for detecting if an expression of the type `_ <bit_op> m\n<cmp_op> c` (where `<bit_op>` is one of {`&`, `|`} and `<cmp_op>` is one of\n{`!=`, `>=`, `>`, `!=`, `>=`, `>`}) can be determined from the following\ntable:\n\n|Comparison |Bit Op|Example |is always|Formula |\n|------------|------|------------|---------|----------------------|\n|`==` or `!=`| `&` |`x & 2 == 3`|`false` |`c & m != c` |\n|`<` or `>=`| `&` |`x & 2 < 3` |`true` |`m < c` |\n|`>` or `<=`| `&` |`x & 1 > 1` |`false` |`m <= c` |\n|`==` or `!=`| `|` |`x | 1 == 0`|`false` |`c | m != c` |\n|`<` or `>=`| `|` |`x | 1 < 1` |`false` |`m >= c` |\n|`<=` or `>` | `|` |`x | 1 > 0` |`true` |`m > c` |"##, | 5113 | description: r##"Checks for incompatible bit masks in comparisons.\n\nThe formula for detecting if an expression of the type `_ <bit_op> m\n<cmp_op> c` (where `<bit_op>` is one of {`&`, `|`} and `<cmp_op>` is one of\n{`!=`, `>=`, `>`, `!=`, `>=`, `>`}) can be determined from the following\ntable:\n\n|Comparison |Bit Op|Example |is always|Formula |\n|------------|------|------------|---------|----------------------|\n|`==` or `!=`| `&` |`x & 2 == 3`|`false` |`c & m != c` |\n|`<` or `>=`| `&` |`x & 2 < 3` |`true` |`m < c` |\n|`>` or `<=`| `&` |`x & 1 > 1` |`false` |`m <= c` |\n|`==` or `!=`| `|` |`x | 1 == 0`|`false` |`c | m != c` |\n|`<` or `>=`| `|` |`x | 1 < 1` |`false` |`m >= c` |\n|`<=` or `>` | `|` |`x | 1 > 0` |`true` |`m > c` |"##, |
4564 | }, | 5114 | }, |
4565 | LintCompletion { | 5115 | Lint { |
4566 | label: "clippy::bind_instead_of_map", | 5116 | label: "clippy::bind_instead_of_map", |
4567 | description: r##"Checks for usage of `_.and_then(|x| Some(y))`, `_.and_then(|x| Ok(y))` or\n`_.or_else(|x| Err(y))`."##, | 5117 | description: r##"Checks for usage of `_.and_then(|x| Some(y))`, `_.and_then(|x| Ok(y))` or\n`_.or_else(|x| Err(y))`."##, |
4568 | }, | 5118 | }, |
4569 | LintCompletion { | 5119 | Lint { |
4570 | label: "clippy::blacklisted_name", | 5120 | label: "clippy::blacklisted_name", |
4571 | description: r##"Checks for usage of blacklisted names for variables, such\nas `foo`."##, | 5121 | description: r##"Checks for usage of blacklisted names for variables, such\nas `foo`."##, |
4572 | }, | 5122 | }, |
4573 | LintCompletion { | 5123 | Lint { |
4574 | label: "clippy::blanket_clippy_restriction_lints", | 5124 | label: "clippy::blanket_clippy_restriction_lints", |
4575 | description: r##"Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category."##, | 5125 | description: r##"Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category."##, |
4576 | }, | 5126 | }, |
4577 | LintCompletion { | 5127 | Lint { |
4578 | label: "clippy::blocks_in_if_conditions", | 5128 | label: "clippy::blocks_in_if_conditions", |
4579 | description: r##"Checks for `if` conditions that use blocks containing an\nexpression, statements or conditions that use closures with blocks."##, | 5129 | description: r##"Checks for `if` conditions that use blocks containing an\nexpression, statements or conditions that use closures with blocks."##, |
4580 | }, | 5130 | }, |
4581 | LintCompletion { | 5131 | Lint { |
5132 | label: "clippy::bool_assert_comparison", | ||
5133 | description: r##"This lint warns about boolean comparisons in assert-like macros."##, | ||
5134 | }, | ||
5135 | Lint { | ||
4582 | label: "clippy::bool_comparison", | 5136 | label: "clippy::bool_comparison", |
4583 | description: r##"Checks for expressions of the form `x == true`,\n`x != true` and order comparisons such as `x < true` (or vice versa) and\nsuggest using the variable directly."##, | 5137 | description: r##"Checks for expressions of the form `x == true`,\n`x != true` and order comparisons such as `x < true` (or vice versa) and\nsuggest using the variable directly."##, |
4584 | }, | 5138 | }, |
4585 | LintCompletion { | 5139 | Lint { |
4586 | label: "clippy::borrow_interior_mutable_const", | 5140 | label: "clippy::borrow_interior_mutable_const", |
4587 | description: r##"Checks if `const` items which is interior mutable (e.g.,\ncontains a `Cell`, `Mutex`, `AtomicXxxx`, etc.) has been borrowed directly."##, | 5141 | description: r##"Checks if `const` items which is interior mutable (e.g.,\ncontains a `Cell`, `Mutex`, `AtomicXxxx`, etc.) has been borrowed directly."##, |
4588 | }, | 5142 | }, |
4589 | LintCompletion { | 5143 | Lint { |
4590 | label: "clippy::borrowed_box", | 5144 | label: "clippy::borrowed_box", |
4591 | description: r##"Checks for use of `&Box<T>` anywhere in the code.\nCheck the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information."##, | 5145 | description: r##"Checks for use of `&Box<T>` anywhere in the code.\nCheck the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information."##, |
4592 | }, | 5146 | }, |
4593 | LintCompletion { | 5147 | Lint { |
4594 | label: "clippy::box_vec", | 5148 | label: "clippy::box_vec", |
4595 | description: r##"Checks for use of `Box<Vec<_>>` anywhere in the code.\nCheck the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information."##, | 5149 | description: r##"Checks for use of `Box<Vec<_>>` anywhere in the code.\nCheck the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information."##, |
4596 | }, | 5150 | }, |
4597 | LintCompletion { | 5151 | Lint { |
4598 | label: "clippy::boxed_local", | 5152 | label: "clippy::boxed_local", |
4599 | description: r##"Checks for usage of `Box<T>` where an unboxed `T` would\nwork fine."##, | 5153 | description: r##"Checks for usage of `Box<T>` where an unboxed `T` would\nwork fine."##, |
4600 | }, | 5154 | }, |
4601 | LintCompletion { | 5155 | Lint { |
5156 | label: "clippy::branches_sharing_code", | ||
5157 | description: r##"Checks if the `if` and `else` block contain shared code that can be\nmoved out of the blocks."##, | ||
5158 | }, | ||
5159 | Lint { | ||
4602 | label: "clippy::builtin_type_shadow", | 5160 | label: "clippy::builtin_type_shadow", |
4603 | description: r##"Warns if a generic shadows a built-in type."##, | 5161 | description: r##"Warns if a generic shadows a built-in type."##, |
4604 | }, | 5162 | }, |
4605 | LintCompletion { | 5163 | Lint { |
4606 | label: "clippy::bytes_nth", | 5164 | label: "clippy::bytes_nth", |
4607 | description: r##"Checks for the use of `.bytes().nth()`."##, | 5165 | description: r##"Checks for the use of `.bytes().nth()`."##, |
4608 | }, | 5166 | }, |
4609 | LintCompletion { | 5167 | Lint { |
4610 | label: "clippy::cargo_common_metadata", | 5168 | label: "clippy::cargo_common_metadata", |
4611 | description: r##"Checks to see if all common metadata is defined in\n`Cargo.toml`. See: https://rust-lang-nursery.github.io/api-guidelines/documentation.html#cargotoml-includes-all-common-metadata-c-metadata"##, | 5169 | description: r##"Checks to see if all common metadata is defined in\n`Cargo.toml`. See: https://rust-lang-nursery.github.io/api-guidelines/documentation.html#cargotoml-includes-all-common-metadata-c-metadata"##, |
4612 | }, | 5170 | }, |
4613 | LintCompletion { | 5171 | Lint { |
4614 | label: "clippy::case_sensitive_file_extension_comparisons", | 5172 | label: "clippy::case_sensitive_file_extension_comparisons", |
4615 | description: r##"Checks for calls to `ends_with` with possible file extensions\nand suggests to use a case-insensitive approach instead."##, | 5173 | description: r##"Checks for calls to `ends_with` with possible file extensions\nand suggests to use a case-insensitive approach instead."##, |
4616 | }, | 5174 | }, |
4617 | LintCompletion { | 5175 | Lint { |
4618 | label: "clippy::cast_lossless", | 5176 | label: "clippy::cast_lossless", |
4619 | description: r##"Checks for casts between numerical types that may\nbe replaced by safe conversion functions."##, | 5177 | description: r##"Checks for casts between numerical types that may\nbe replaced by safe conversion functions."##, |
4620 | }, | 5178 | }, |
4621 | LintCompletion { | 5179 | Lint { |
4622 | label: "clippy::cast_possible_truncation", | 5180 | label: "clippy::cast_possible_truncation", |
4623 | description: r##"Checks for casts between numerical types that may\ntruncate large values. This is expected behavior, so the cast is `Allow` by\ndefault."##, | 5181 | description: r##"Checks for casts between numerical types that may\ntruncate large values. This is expected behavior, so the cast is `Allow` by\ndefault."##, |
4624 | }, | 5182 | }, |
4625 | LintCompletion { | 5183 | Lint { |
4626 | label: "clippy::cast_possible_wrap", | 5184 | label: "clippy::cast_possible_wrap", |
4627 | description: r##"Checks for casts from an unsigned type to a signed type of\nthe same size. Performing such a cast is a 'no-op' for the compiler,\ni.e., nothing is changed at the bit level, and the binary representation of\nthe value is reinterpreted. This can cause wrapping if the value is too big\nfor the target signed type. However, the cast works as defined, so this lint\nis `Allow` by default."##, | 5185 | description: r##"Checks for casts from an unsigned type to a signed type of\nthe same size. Performing such a cast is a 'no-op' for the compiler,\ni.e., nothing is changed at the bit level, and the binary representation of\nthe value is reinterpreted. This can cause wrapping if the value is too big\nfor the target signed type. However, the cast works as defined, so this lint\nis `Allow` by default."##, |
4628 | }, | 5186 | }, |
4629 | LintCompletion { | 5187 | Lint { |
4630 | label: "clippy::cast_precision_loss", | 5188 | label: "clippy::cast_precision_loss", |
4631 | description: r##"Checks for casts from any numerical to a float type where\nthe receiving type cannot store all values from the original type without\nrounding errors. This possible rounding is to be expected, so this lint is\n`Allow` by default.\n\nBasically, this warns on casting any integer with 32 or more bits to `f32`\nor any 64-bit integer to `f64`."##, | 5189 | description: r##"Checks for casts from any numerical to a float type where\nthe receiving type cannot store all values from the original type without\nrounding errors. This possible rounding is to be expected, so this lint is\n`Allow` by default.\n\nBasically, this warns on casting any integer with 32 or more bits to `f32`\nor any 64-bit integer to `f64`."##, |
4632 | }, | 5190 | }, |
4633 | LintCompletion { | 5191 | Lint { |
4634 | label: "clippy::cast_ptr_alignment", | 5192 | label: "clippy::cast_ptr_alignment", |
4635 | description: r##"Checks for casts, using `as` or `pointer::cast`,\nfrom a less-strictly-aligned pointer to a more-strictly-aligned pointer"##, | 5193 | description: r##"Checks for casts, using `as` or `pointer::cast`,\nfrom a less-strictly-aligned pointer to a more-strictly-aligned pointer"##, |
4636 | }, | 5194 | }, |
4637 | LintCompletion { | 5195 | Lint { |
4638 | label: "clippy::cast_ref_to_mut", | 5196 | label: "clippy::cast_ref_to_mut", |
4639 | description: r##"Checks for casts of `&T` to `&mut T` anywhere in the code."##, | 5197 | description: r##"Checks for casts of `&T` to `&mut T` anywhere in the code."##, |
4640 | }, | 5198 | }, |
4641 | LintCompletion { | 5199 | Lint { |
4642 | label: "clippy::cast_sign_loss", | 5200 | label: "clippy::cast_sign_loss", |
4643 | description: r##"Checks for casts from a signed to an unsigned numerical\ntype. In this case, negative values wrap around to large positive values,\nwhich can be quite surprising in practice. However, as the cast works as\ndefined, this lint is `Allow` by default."##, | 5201 | description: r##"Checks for casts from a signed to an unsigned numerical\ntype. In this case, negative values wrap around to large positive values,\nwhich can be quite surprising in practice. However, as the cast works as\ndefined, this lint is `Allow` by default."##, |
4644 | }, | 5202 | }, |
4645 | LintCompletion { | 5203 | Lint { |
4646 | label: "clippy::char_lit_as_u8", | 5204 | label: "clippy::char_lit_as_u8", |
4647 | description: r##"Checks for expressions where a character literal is cast\nto `u8` and suggests using a byte literal instead."##, | 5205 | description: r##"Checks for expressions where a character literal is cast\nto `u8` and suggests using a byte literal instead."##, |
4648 | }, | 5206 | }, |
4649 | LintCompletion { | 5207 | Lint { |
4650 | label: "clippy::chars_last_cmp", | 5208 | label: "clippy::chars_last_cmp", |
4651 | description: r##"Checks for usage of `_.chars().last()` or\n`_.chars().next_back()` on a `str` to check if it ends with a given char."##, | 5209 | description: r##"Checks for usage of `_.chars().last()` or\n`_.chars().next_back()` on a `str` to check if it ends with a given char."##, |
4652 | }, | 5210 | }, |
4653 | LintCompletion { | 5211 | Lint { |
4654 | label: "clippy::chars_next_cmp", | 5212 | label: "clippy::chars_next_cmp", |
4655 | description: r##"Checks for usage of `.chars().next()` on a `str` to check\nif it starts with a given char."##, | 5213 | description: r##"Checks for usage of `.chars().next()` on a `str` to check\nif it starts with a given char."##, |
4656 | }, | 5214 | }, |
4657 | LintCompletion { | 5215 | Lint { |
4658 | label: "clippy::checked_conversions", | 5216 | label: "clippy::checked_conversions", |
4659 | description: r##"Checks for explicit bounds checking when casting."##, | 5217 | description: r##"Checks for explicit bounds checking when casting."##, |
4660 | }, | 5218 | }, |
4661 | LintCompletion { | 5219 | Lint { |
4662 | label: "clippy::clone_double_ref", | 5220 | label: "clippy::clone_double_ref", |
4663 | description: r##"Checks for usage of `.clone()` on an `&&T`."##, | 5221 | description: r##"Checks for usage of `.clone()` on an `&&T`."##, |
4664 | }, | 5222 | }, |
4665 | LintCompletion { | 5223 | Lint { |
4666 | label: "clippy::clone_on_copy", | 5224 | label: "clippy::clone_on_copy", |
4667 | description: r##"Checks for usage of `.clone()` on a `Copy` type."##, | 5225 | description: r##"Checks for usage of `.clone()` on a `Copy` type."##, |
4668 | }, | 5226 | }, |
4669 | LintCompletion { | 5227 | Lint { |
4670 | label: "clippy::clone_on_ref_ptr", | 5228 | label: "clippy::clone_on_ref_ptr", |
4671 | description: r##"Checks for usage of `.clone()` on a ref-counted pointer,\n(`Rc`, `Arc`, `rc::Weak`, or `sync::Weak`), and suggests calling Clone via unified\nfunction syntax instead (e.g., `Rc::clone(foo)`)."##, | 5229 | description: r##"Checks for usage of `.clone()` on a ref-counted pointer,\n(`Rc`, `Arc`, `rc::Weak`, or `sync::Weak`), and suggests calling Clone via unified\nfunction syntax instead (e.g., `Rc::clone(foo)`)."##, |
4672 | }, | 5230 | }, |
4673 | LintCompletion { label: "clippy::cmp_nan", description: r##"Checks for comparisons to NaN."## }, | 5231 | Lint { |
4674 | LintCompletion { | 5232 | label: "clippy::cloned_instead_of_copied", |
5233 | description: r##"Checks for usages of `cloned()` on an `Iterator` or `Option` where\n`copied()` could be used instead."##, | ||
5234 | }, | ||
5235 | Lint { label: "clippy::cmp_nan", description: r##"Checks for comparisons to NaN."## }, | ||
5236 | Lint { | ||
4675 | label: "clippy::cmp_null", | 5237 | label: "clippy::cmp_null", |
4676 | description: r##"This lint checks for equality comparisons with `ptr::null`"##, | 5238 | description: r##"This lint checks for equality comparisons with `ptr::null`"##, |
4677 | }, | 5239 | }, |
4678 | LintCompletion { | 5240 | Lint { |
4679 | label: "clippy::cmp_owned", | 5241 | label: "clippy::cmp_owned", |
4680 | description: r##"Checks for conversions to owned values just for the sake\nof a comparison."##, | 5242 | description: r##"Checks for conversions to owned values just for the sake\nof a comparison."##, |
4681 | }, | 5243 | }, |
4682 | LintCompletion { | 5244 | Lint { |
4683 | label: "clippy::cognitive_complexity", | 5245 | label: "clippy::cognitive_complexity", |
4684 | description: r##"Checks for methods with high cognitive complexity."##, | 5246 | description: r##"Checks for methods with high cognitive complexity."##, |
4685 | }, | 5247 | }, |
4686 | LintCompletion { | 5248 | Lint { |
4687 | label: "clippy::collapsible_else_if", | 5249 | label: "clippy::collapsible_else_if", |
4688 | description: r##"Checks for collapsible `else { if ... }` expressions\nthat can be collapsed to `else if ...`."##, | 5250 | description: r##"Checks for collapsible `else { if ... }` expressions\nthat can be collapsed to `else if ...`."##, |
4689 | }, | 5251 | }, |
4690 | LintCompletion { | 5252 | Lint { |
4691 | label: "clippy::collapsible_if", | 5253 | label: "clippy::collapsible_if", |
4692 | description: r##"Checks for nested `if` statements which can be collapsed\nby `&&`-combining their conditions."##, | 5254 | description: r##"Checks for nested `if` statements which can be collapsed\nby `&&`-combining their conditions."##, |
4693 | }, | 5255 | }, |
4694 | LintCompletion { | 5256 | Lint { |
4695 | label: "clippy::collapsible_match", | 5257 | label: "clippy::collapsible_match", |
4696 | description: r##"Finds nested `match` or `if let` expressions where the patterns may be \"collapsed\" together\nwithout adding any branches.\n\nNote that this lint is not intended to find _all_ cases where nested match patterns can be merged, but only\ncases where merging would most likely make the code more readable."##, | 5258 | description: r##"Finds nested `match` or `if let` expressions where the patterns may be \"collapsed\" together\nwithout adding any branches.\n\nNote that this lint is not intended to find _all_ cases where nested match patterns can be merged, but only\ncases where merging would most likely make the code more readable."##, |
4697 | }, | 5259 | }, |
4698 | LintCompletion { | 5260 | Lint { |
4699 | label: "clippy::comparison_chain", | 5261 | label: "clippy::comparison_chain", |
4700 | description: r##"Checks comparison chains written with `if` that can be\nrewritten with `match` and `cmp`."##, | 5262 | description: r##"Checks comparison chains written with `if` that can be\nrewritten with `match` and `cmp`."##, |
4701 | }, | 5263 | }, |
4702 | LintCompletion { | 5264 | Lint { |
4703 | label: "clippy::comparison_to_empty", | 5265 | label: "clippy::comparison_to_empty", |
4704 | description: r##"Checks for comparing to an empty slice such as `\"\"` or `[]`,\nand suggests using `.is_empty()` where applicable."##, | 5266 | description: r##"Checks for comparing to an empty slice such as `\"\"` or `[]`,\nand suggests using `.is_empty()` where applicable."##, |
4705 | }, | 5267 | }, |
4706 | LintCompletion { | 5268 | Lint { |
4707 | label: "clippy::copy_iterator", | 5269 | label: "clippy::copy_iterator", |
4708 | description: r##"Checks for types that implement `Copy` as well as\n`Iterator`."##, | 5270 | description: r##"Checks for types that implement `Copy` as well as\n`Iterator`."##, |
4709 | }, | 5271 | }, |
4710 | LintCompletion { | 5272 | Lint { |
4711 | label: "clippy::create_dir", | 5273 | label: "clippy::create_dir", |
4712 | description: r##"Checks usage of `std::fs::create_dir` and suggest using `std::fs::create_dir_all` instead."##, | 5274 | description: r##"Checks usage of `std::fs::create_dir` and suggest using `std::fs::create_dir_all` instead."##, |
4713 | }, | 5275 | }, |
4714 | LintCompletion { | 5276 | Lint { |
4715 | label: "clippy::crosspointer_transmute", | 5277 | label: "clippy::crosspointer_transmute", |
4716 | description: r##"Checks for transmutes between a type `T` and `*T`."##, | 5278 | description: r##"Checks for transmutes between a type `T` and `*T`."##, |
4717 | }, | 5279 | }, |
4718 | LintCompletion { | 5280 | Lint { label: "clippy::dbg_macro", description: r##"Checks for usage of dbg!() macro."## }, |
4719 | label: "clippy::dbg_macro", | 5281 | Lint { |
4720 | description: r##"Checks for usage of dbg!() macro."##, | ||
4721 | }, | ||
4722 | LintCompletion { | ||
4723 | label: "clippy::debug_assert_with_mut_call", | 5282 | label: "clippy::debug_assert_with_mut_call", |
4724 | description: r##"Checks for function/method calls with a mutable\nparameter in `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!` macros."##, | 5283 | description: r##"Checks for function/method calls with a mutable\nparameter in `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!` macros."##, |
4725 | }, | 5284 | }, |
4726 | LintCompletion { | 5285 | Lint { |
4727 | label: "clippy::decimal_literal_representation", | 5286 | label: "clippy::decimal_literal_representation", |
4728 | description: r##"Warns if there is a better representation for a numeric literal."##, | 5287 | description: r##"Warns if there is a better representation for a numeric literal."##, |
4729 | }, | 5288 | }, |
4730 | LintCompletion { | 5289 | Lint { |
4731 | label: "clippy::declare_interior_mutable_const", | 5290 | label: "clippy::declare_interior_mutable_const", |
4732 | description: r##"Checks for declaration of `const` items which is interior\nmutable (e.g., contains a `Cell`, `Mutex`, `AtomicXxxx`, etc.)."##, | 5291 | description: r##"Checks for declaration of `const` items which is interior\nmutable (e.g., contains a `Cell`, `Mutex`, `AtomicXxxx`, etc.)."##, |
4733 | }, | 5292 | }, |
4734 | LintCompletion { | 5293 | Lint { |
4735 | label: "clippy::default_numeric_fallback", | 5294 | label: "clippy::default_numeric_fallback", |
4736 | description: r##"Checks for usage of unconstrained numeric literals which may cause default numeric fallback in type\ninference.\n\nDefault numeric fallback means that if numeric types have not yet been bound to concrete\ntypes at the end of type inference, then integer type is bound to `i32`, and similarly\nfloating type is bound to `f64`.\n\nSee [RFC0212](https://github.com/rust-lang/rfcs/blob/master/text/0212-restore-int-fallback.md) for more information about the fallback."##, | 5295 | description: r##"Checks for usage of unconstrained numeric literals which may cause default numeric fallback in type\ninference.\n\nDefault numeric fallback means that if numeric types have not yet been bound to concrete\ntypes at the end of type inference, then integer type is bound to `i32`, and similarly\nfloating type is bound to `f64`.\n\nSee [RFC0212](https://github.com/rust-lang/rfcs/blob/master/text/0212-restore-int-fallback.md) for more information about the fallback."##, |
4737 | }, | 5296 | }, |
4738 | LintCompletion { | 5297 | Lint { |
4739 | label: "clippy::default_trait_access", | 5298 | label: "clippy::default_trait_access", |
4740 | description: r##"Checks for literal calls to `Default::default()`."##, | 5299 | description: r##"Checks for literal calls to `Default::default()`."##, |
4741 | }, | 5300 | }, |
4742 | LintCompletion { | 5301 | Lint { |
4743 | label: "clippy::deprecated_cfg_attr", | 5302 | label: "clippy::deprecated_cfg_attr", |
4744 | description: r##"Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it\nwith `#[rustfmt::skip]`."##, | 5303 | description: r##"Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it\nwith `#[rustfmt::skip]`."##, |
4745 | }, | 5304 | }, |
4746 | LintCompletion { | 5305 | Lint { |
4747 | label: "clippy::deprecated_semver", | 5306 | label: "clippy::deprecated_semver", |
4748 | description: r##"Checks for `#[deprecated]` annotations with a `since`\nfield that is not a valid semantic version."##, | 5307 | description: r##"Checks for `#[deprecated]` annotations with a `since`\nfield that is not a valid semantic version."##, |
4749 | }, | 5308 | }, |
4750 | LintCompletion { | 5309 | Lint { |
4751 | label: "clippy::deref_addrof", | 5310 | label: "clippy::deref_addrof", |
4752 | description: r##"Checks for usage of `*&` and `*&mut` in expressions."##, | 5311 | description: r##"Checks for usage of `*&` and `*&mut` in expressions."##, |
4753 | }, | 5312 | }, |
4754 | LintCompletion { | 5313 | Lint { |
4755 | label: "clippy::derive_hash_xor_eq", | 5314 | label: "clippy::derive_hash_xor_eq", |
4756 | description: r##"Checks for deriving `Hash` but implementing `PartialEq`\nexplicitly or vice versa."##, | 5315 | description: r##"Checks for deriving `Hash` but implementing `PartialEq`\nexplicitly or vice versa."##, |
4757 | }, | 5316 | }, |
4758 | LintCompletion { | 5317 | Lint { |
4759 | label: "clippy::derive_ord_xor_partial_ord", | 5318 | label: "clippy::derive_ord_xor_partial_ord", |
4760 | description: r##"Checks for deriving `Ord` but implementing `PartialOrd`\nexplicitly or vice versa."##, | 5319 | description: r##"Checks for deriving `Ord` but implementing `PartialOrd`\nexplicitly or vice versa."##, |
4761 | }, | 5320 | }, |
4762 | LintCompletion { | 5321 | Lint { |
4763 | label: "clippy::disallowed_method", | 5322 | label: "clippy::disallowed_method", |
4764 | description: r##"Denies the configured methods and functions in clippy.toml"##, | 5323 | description: r##"Denies the configured methods and functions in clippy.toml"##, |
4765 | }, | 5324 | }, |
4766 | LintCompletion { | 5325 | Lint { |
4767 | label: "clippy::diverging_sub_expression", | 5326 | label: "clippy::diverging_sub_expression", |
4768 | description: r##"Checks for diverging calls that are not match arms or\nstatements."##, | 5327 | description: r##"Checks for diverging calls that are not match arms or\nstatements."##, |
4769 | }, | 5328 | }, |
4770 | LintCompletion { | 5329 | Lint { |
4771 | label: "clippy::doc_markdown", | 5330 | label: "clippy::doc_markdown", |
4772 | description: r##"Checks for the presence of `_`, `::` or camel-case words\noutside ticks in documentation."##, | 5331 | description: r##"Checks for the presence of `_`, `::` or camel-case words\noutside ticks in documentation."##, |
4773 | }, | 5332 | }, |
4774 | LintCompletion { | 5333 | Lint { |
4775 | label: "clippy::double_comparisons", | 5334 | label: "clippy::double_comparisons", |
4776 | description: r##"Checks for double comparisons that could be simplified to a single expression."##, | 5335 | description: r##"Checks for double comparisons that could be simplified to a single expression."##, |
4777 | }, | 5336 | }, |
4778 | LintCompletion { | 5337 | Lint { |
4779 | label: "clippy::double_must_use", | 5338 | label: "clippy::double_must_use", |
4780 | description: r##"Checks for a [`#[must_use]`] attribute without\nfurther information on functions and methods that return a type already\nmarked as `#[must_use]`.\n\n[`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"##, | 5339 | description: r##"Checks for a [`#[must_use]`] attribute without\nfurther information on functions and methods that return a type already\nmarked as `#[must_use]`.\n\n[`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"##, |
4781 | }, | 5340 | }, |
4782 | LintCompletion { | 5341 | Lint { |
4783 | label: "clippy::double_neg", | 5342 | label: "clippy::double_neg", |
4784 | description: r##"Detects expressions of the form `--x`."##, | 5343 | description: r##"Detects expressions of the form `--x`."##, |
4785 | }, | 5344 | }, |
4786 | LintCompletion { | 5345 | Lint { |
4787 | label: "clippy::double_parens", | 5346 | label: "clippy::double_parens", |
4788 | description: r##"Checks for unnecessary double parentheses."##, | 5347 | description: r##"Checks for unnecessary double parentheses."##, |
4789 | }, | 5348 | }, |
4790 | LintCompletion { | 5349 | Lint { |
4791 | label: "clippy::drop_bounds", | ||
4792 | description: r##"Nothing. This lint has been deprecated."##, | ||
4793 | }, | ||
4794 | LintCompletion { | ||
4795 | label: "clippy::drop_copy", | 5350 | label: "clippy::drop_copy", |
4796 | description: r##"Checks for calls to `std::mem::drop` with a value\nthat derives the Copy trait"##, | 5351 | description: r##"Checks for calls to `std::mem::drop` with a value\nthat derives the Copy trait"##, |
4797 | }, | 5352 | }, |
4798 | LintCompletion { | 5353 | Lint { |
4799 | label: "clippy::drop_ref", | 5354 | label: "clippy::drop_ref", |
4800 | description: r##"Checks for calls to `std::mem::drop` with a reference\ninstead of an owned value."##, | 5355 | description: r##"Checks for calls to `std::mem::drop` with a reference\ninstead of an owned value."##, |
4801 | }, | 5356 | }, |
4802 | LintCompletion { | 5357 | Lint { |
4803 | label: "clippy::duplicate_underscore_argument", | 5358 | label: "clippy::duplicate_underscore_argument", |
4804 | description: r##"Checks for function arguments having the similar names\ndiffering by an underscore."##, | 5359 | description: r##"Checks for function arguments having the similar names\ndiffering by an underscore."##, |
4805 | }, | 5360 | }, |
4806 | LintCompletion { | 5361 | Lint { |
4807 | label: "clippy::duration_subsec", | 5362 | label: "clippy::duration_subsec", |
4808 | description: r##"Checks for calculation of subsecond microseconds or milliseconds\nfrom other `Duration` methods."##, | 5363 | description: r##"Checks for calculation of subsecond microseconds or milliseconds\nfrom other `Duration` methods."##, |
4809 | }, | 5364 | }, |
4810 | LintCompletion { | 5365 | Lint { |
4811 | label: "clippy::else_if_without_else", | 5366 | label: "clippy::else_if_without_else", |
4812 | description: r##"Checks for usage of if expressions with an `else if` branch,\nbut without a final `else` branch."##, | 5367 | description: r##"Checks for usage of if expressions with an `else if` branch,\nbut without a final `else` branch."##, |
4813 | }, | 5368 | }, |
4814 | LintCompletion { | 5369 | Lint { |
4815 | label: "clippy::empty_enum", | 5370 | label: "clippy::empty_enum", |
4816 | description: r##"Checks for `enum`s with no variants.\n\nAs of this writing, the `never_type` is still a\nnightly-only experimental API. Therefore, this lint is only triggered\nif the `never_type` is enabled."##, | 5371 | description: r##"Checks for `enum`s with no variants.\n\nAs of this writing, the `never_type` is still a\nnightly-only experimental API. Therefore, this lint is only triggered\nif the `never_type` is enabled."##, |
4817 | }, | 5372 | }, |
4818 | LintCompletion { | 5373 | Lint { |
4819 | label: "clippy::empty_line_after_outer_attr", | 5374 | label: "clippy::empty_line_after_outer_attr", |
4820 | description: r##"Checks for empty lines after outer attributes"##, | 5375 | description: r##"Checks for empty lines after outer attributes"##, |
4821 | }, | 5376 | }, |
4822 | LintCompletion { | 5377 | Lint { label: "clippy::empty_loop", description: r##"Checks for empty `loop` expressions."## }, |
4823 | label: "clippy::empty_loop", | 5378 | Lint { |
4824 | description: r##"Checks for empty `loop` expressions."##, | ||
4825 | }, | ||
4826 | LintCompletion { | ||
4827 | label: "clippy::enum_clike_unportable_variant", | 5379 | label: "clippy::enum_clike_unportable_variant", |
4828 | description: r##"Checks for C-like enumerations that are\n`repr(isize/usize)` and have values that don't fit into an `i32`."##, | 5380 | description: r##"Checks for C-like enumerations that are\n`repr(isize/usize)` and have values that don't fit into an `i32`."##, |
4829 | }, | 5381 | }, |
4830 | LintCompletion { | 5382 | Lint { label: "clippy::enum_glob_use", description: r##"Checks for `use Enum::*`."## }, |
4831 | label: "clippy::enum_glob_use", | 5383 | Lint { |
4832 | description: r##"Checks for `use Enum::*`."##, | ||
4833 | }, | ||
4834 | LintCompletion { | ||
4835 | label: "clippy::enum_variant_names", | 5384 | label: "clippy::enum_variant_names", |
4836 | description: r##"Detects enumeration variants that are prefixed or suffixed\nby the same characters."##, | 5385 | description: r##"Detects enumeration variants that are prefixed or suffixed\nby the same characters."##, |
4837 | }, | 5386 | }, |
4838 | LintCompletion { | 5387 | Lint { |
4839 | label: "clippy::eq_op", | 5388 | label: "clippy::eq_op", |
4840 | description: r##"Checks for equal operands to comparison, logical and\nbitwise, difference and division binary operators (`==`, `>`, etc., `&&`,\n`||`, `&`, `|`, `^`, `-` and `/`)."##, | 5389 | description: r##"Checks for equal operands to comparison, logical and\nbitwise, difference and division binary operators (`==`, `>`, etc., `&&`,\n`||`, `&`, `|`, `^`, `-` and `/`)."##, |
4841 | }, | 5390 | }, |
4842 | LintCompletion { | 5391 | Lint { |
4843 | label: "clippy::erasing_op", | 5392 | label: "clippy::erasing_op", |
4844 | description: r##"Checks for erasing operations, e.g., `x * 0`."##, | 5393 | description: r##"Checks for erasing operations, e.g., `x * 0`."##, |
4845 | }, | 5394 | }, |
4846 | LintCompletion { | 5395 | Lint { |
4847 | label: "clippy::eval_order_dependence", | 5396 | label: "clippy::eval_order_dependence", |
4848 | description: r##"Checks for a read and a write to the same variable where\nwhether the read occurs before or after the write depends on the evaluation\norder of sub-expressions."##, | 5397 | description: r##"Checks for a read and a write to the same variable where\nwhether the read occurs before or after the write depends on the evaluation\norder of sub-expressions."##, |
4849 | }, | 5398 | }, |
4850 | LintCompletion { | 5399 | Lint { |
4851 | label: "clippy::excessive_precision", | 5400 | label: "clippy::excessive_precision", |
4852 | description: r##"Checks for float literals with a precision greater\nthan that supported by the underlying type."##, | 5401 | description: r##"Checks for float literals with a precision greater\nthan that supported by the underlying type."##, |
4853 | }, | 5402 | }, |
4854 | LintCompletion { | 5403 | Lint { |
4855 | label: "clippy::exhaustive_enums", | 5404 | label: "clippy::exhaustive_enums", |
4856 | description: r##"Warns on any exported `enum`s that are not tagged `#[non_exhaustive]`"##, | 5405 | description: r##"Warns on any exported `enum`s that are not tagged `#[non_exhaustive]`"##, |
4857 | }, | 5406 | }, |
4858 | LintCompletion { | 5407 | Lint { |
4859 | label: "clippy::exhaustive_structs", | 5408 | label: "clippy::exhaustive_structs", |
4860 | description: r##"Warns on any exported `structs`s that are not tagged `#[non_exhaustive]`"##, | 5409 | description: r##"Warns on any exported `structs`s that are not tagged `#[non_exhaustive]`"##, |
4861 | }, | 5410 | }, |
4862 | LintCompletion { | 5411 | Lint { |
4863 | label: "clippy::exit", | 5412 | label: "clippy::exit", |
4864 | description: r##"`exit()` terminates the program and doesn't provide a\nstack trace."##, | 5413 | description: r##"`exit()` terminates the program and doesn't provide a\nstack trace."##, |
4865 | }, | 5414 | }, |
4866 | LintCompletion { | 5415 | Lint { |
4867 | label: "clippy::expect_fun_call", | 5416 | label: "clippy::expect_fun_call", |
4868 | description: r##"Checks for calls to `.expect(&format!(...))`, `.expect(foo(..))`,\netc., and suggests to use `unwrap_or_else` instead"##, | 5417 | description: r##"Checks for calls to `.expect(&format!(...))`, `.expect(foo(..))`,\netc., and suggests to use `unwrap_or_else` instead"##, |
4869 | }, | 5418 | }, |
4870 | LintCompletion { | 5419 | Lint { |
4871 | label: "clippy::expect_used", | 5420 | label: "clippy::expect_used", |
4872 | description: r##"Checks for `.expect()` calls on `Option`s and `Result`s."##, | 5421 | description: r##"Checks for `.expect()` calls on `Option`s and `Result`s."##, |
4873 | }, | 5422 | }, |
4874 | LintCompletion { | 5423 | Lint { |
4875 | label: "clippy::expl_impl_clone_on_copy", | 5424 | label: "clippy::expl_impl_clone_on_copy", |
4876 | description: r##"Checks for explicit `Clone` implementations for `Copy`\ntypes."##, | 5425 | description: r##"Checks for explicit `Clone` implementations for `Copy`\ntypes."##, |
4877 | }, | 5426 | }, |
4878 | LintCompletion { | 5427 | Lint { |
4879 | label: "clippy::explicit_counter_loop", | 5428 | label: "clippy::explicit_counter_loop", |
4880 | description: r##"Checks `for` loops over slices with an explicit counter\nand suggests the use of `.enumerate()`."##, | 5429 | description: r##"Checks `for` loops over slices with an explicit counter\nand suggests the use of `.enumerate()`."##, |
4881 | }, | 5430 | }, |
4882 | LintCompletion { | 5431 | Lint { |
4883 | label: "clippy::explicit_deref_methods", | 5432 | label: "clippy::explicit_deref_methods", |
4884 | description: r##"Checks for explicit `deref()` or `deref_mut()` method calls."##, | 5433 | description: r##"Checks for explicit `deref()` or `deref_mut()` method calls."##, |
4885 | }, | 5434 | }, |
4886 | LintCompletion { | 5435 | Lint { |
4887 | label: "clippy::explicit_into_iter_loop", | 5436 | label: "clippy::explicit_into_iter_loop", |
4888 | description: r##"Checks for loops on `y.into_iter()` where `y` will do, and\nsuggests the latter."##, | 5437 | description: r##"Checks for loops on `y.into_iter()` where `y` will do, and\nsuggests the latter."##, |
4889 | }, | 5438 | }, |
4890 | LintCompletion { | 5439 | Lint { |
4891 | label: "clippy::explicit_iter_loop", | 5440 | label: "clippy::explicit_iter_loop", |
4892 | description: r##"Checks for loops on `x.iter()` where `&x` will do, and\nsuggests the latter."##, | 5441 | description: r##"Checks for loops on `x.iter()` where `&x` will do, and\nsuggests the latter."##, |
4893 | }, | 5442 | }, |
4894 | LintCompletion { | 5443 | Lint { |
4895 | label: "clippy::explicit_write", | 5444 | label: "clippy::explicit_write", |
4896 | description: r##"Checks for usage of `write!()` / `writeln()!` which can be\nreplaced with `(e)print!()` / `(e)println!()`"##, | 5445 | description: r##"Checks for usage of `write!()` / `writeln()!` which can be\nreplaced with `(e)print!()` / `(e)println!()`"##, |
4897 | }, | 5446 | }, |
4898 | LintCompletion { | 5447 | Lint { |
4899 | label: "clippy::extend_from_slice", | 5448 | label: "clippy::extend_from_slice", |
4900 | description: r##"Nothing. This lint has been deprecated."##, | 5449 | description: r##"Nothing. This lint has been deprecated."##, |
4901 | }, | 5450 | }, |
4902 | LintCompletion { | 5451 | Lint { |
4903 | label: "clippy::extra_unused_lifetimes", | 5452 | label: "clippy::extra_unused_lifetimes", |
4904 | description: r##"Checks for lifetimes in generics that are never used\nanywhere else."##, | 5453 | description: r##"Checks for lifetimes in generics that are never used\nanywhere else."##, |
4905 | }, | 5454 | }, |
4906 | LintCompletion { | 5455 | Lint { |
4907 | label: "clippy::fallible_impl_from", | 5456 | label: "clippy::fallible_impl_from", |
4908 | description: r##"Checks for impls of `From<..>` that contain `panic!()` or `unwrap()`"##, | 5457 | description: r##"Checks for impls of `From<..>` that contain `panic!()` or `unwrap()`"##, |
4909 | }, | 5458 | }, |
4910 | LintCompletion { | 5459 | Lint { |
4911 | label: "clippy::field_reassign_with_default", | 5460 | label: "clippy::field_reassign_with_default", |
4912 | description: r##"Checks for immediate reassignment of fields initialized\nwith Default::default()."##, | 5461 | description: r##"Checks for immediate reassignment of fields initialized\nwith Default::default()."##, |
4913 | }, | 5462 | }, |
4914 | LintCompletion { | 5463 | Lint { |
4915 | label: "clippy::filetype_is_file", | 5464 | label: "clippy::filetype_is_file", |
4916 | description: r##"Checks for `FileType::is_file()`."##, | 5465 | description: r##"Checks for `FileType::is_file()`."##, |
4917 | }, | 5466 | }, |
4918 | LintCompletion { | 5467 | Lint { |
4919 | label: "clippy::filter_map", | 5468 | label: "clippy::filter_map", |
4920 | description: r##"Checks for usage of `_.filter(_).map(_)`,\n`_.filter(_).flat_map(_)`, `_.filter_map(_).flat_map(_)` and similar."##, | 5469 | description: r##"Nothing. This lint has been deprecated."##, |
4921 | }, | 5470 | }, |
4922 | LintCompletion { | 5471 | Lint { |
4923 | label: "clippy::filter_map_identity", | 5472 | label: "clippy::filter_map_identity", |
4924 | description: r##"Checks for usage of `filter_map(|x| x)`."##, | 5473 | description: r##"Checks for usage of `filter_map(|x| x)`."##, |
4925 | }, | 5474 | }, |
4926 | LintCompletion { | 5475 | Lint { |
4927 | label: "clippy::filter_map_next", | 5476 | label: "clippy::filter_map_next", |
4928 | description: r##"Checks for usage of `_.filter_map(_).next()`."##, | 5477 | description: r##"Checks for usage of `_.filter_map(_).next()`."##, |
4929 | }, | 5478 | }, |
4930 | LintCompletion { | 5479 | Lint { |
4931 | label: "clippy::filter_next", | 5480 | label: "clippy::filter_next", |
4932 | description: r##"Checks for usage of `_.filter(_).next()`."##, | 5481 | description: r##"Checks for usage of `_.filter(_).next()`."##, |
4933 | }, | 5482 | }, |
4934 | LintCompletion { | 5483 | Lint { label: "clippy::find_map", description: r##"Nothing. This lint has been deprecated."## }, |
4935 | label: "clippy::find_map", | 5484 | Lint { |
4936 | description: r##"Nothing. This lint has been deprecated."##, | ||
4937 | }, | ||
4938 | LintCompletion { | ||
4939 | label: "clippy::flat_map_identity", | 5485 | label: "clippy::flat_map_identity", |
4940 | description: r##"Checks for usage of `flat_map(|x| x)`."##, | 5486 | description: r##"Checks for usage of `flat_map(|x| x)`."##, |
4941 | }, | 5487 | }, |
4942 | LintCompletion { | 5488 | Lint { |
4943 | label: "clippy::float_arithmetic", | 5489 | label: "clippy::flat_map_option", |
4944 | description: r##"Checks for float arithmetic."##, | 5490 | description: r##"Checks for usages of `Iterator::flat_map()` where `filter_map()` could be\nused instead."##, |
4945 | }, | 5491 | }, |
4946 | LintCompletion { | 5492 | Lint { label: "clippy::float_arithmetic", description: r##"Checks for float arithmetic."## }, |
5493 | Lint { | ||
4947 | label: "clippy::float_cmp", | 5494 | label: "clippy::float_cmp", |
4948 | description: r##"Checks for (in-)equality comparisons on floating-point\nvalues (apart from zero), except in functions called `*eq*` (which probably\nimplement equality for a type involving floats)."##, | 5495 | description: r##"Checks for (in-)equality comparisons on floating-point\nvalues (apart from zero), except in functions called `*eq*` (which probably\nimplement equality for a type involving floats)."##, |
4949 | }, | 5496 | }, |
4950 | LintCompletion { | 5497 | Lint { |
4951 | label: "clippy::float_cmp_const", | 5498 | label: "clippy::float_cmp_const", |
4952 | description: r##"Checks for (in-)equality comparisons on floating-point\nvalue and constant, except in functions called `*eq*` (which probably\nimplement equality for a type involving floats)."##, | 5499 | description: r##"Checks for (in-)equality comparisons on floating-point\nvalue and constant, except in functions called `*eq*` (which probably\nimplement equality for a type involving floats)."##, |
4953 | }, | 5500 | }, |
4954 | LintCompletion { | 5501 | Lint { |
4955 | label: "clippy::float_equality_without_abs", | 5502 | label: "clippy::float_equality_without_abs", |
4956 | description: r##"Checks for statements of the form `(a - b) < f32::EPSILON` or\n`(a - b) < f64::EPSILON`. Notes the missing `.abs()`."##, | 5503 | description: r##"Checks for statements of the form `(a - b) < f32::EPSILON` or\n`(a - b) < f64::EPSILON`. Notes the missing `.abs()`."##, |
4957 | }, | 5504 | }, |
4958 | LintCompletion { | 5505 | Lint { |
4959 | label: "clippy::fn_address_comparisons", | 5506 | label: "clippy::fn_address_comparisons", |
4960 | description: r##"Checks for comparisons with an address of a function item."##, | 5507 | description: r##"Checks for comparisons with an address of a function item."##, |
4961 | }, | 5508 | }, |
4962 | LintCompletion { | 5509 | Lint { |
4963 | label: "clippy::fn_params_excessive_bools", | 5510 | label: "clippy::fn_params_excessive_bools", |
4964 | description: r##"Checks for excessive use of\nbools in function definitions."##, | 5511 | description: r##"Checks for excessive use of\nbools in function definitions."##, |
4965 | }, | 5512 | }, |
4966 | LintCompletion { | 5513 | Lint { |
4967 | label: "clippy::fn_to_numeric_cast", | 5514 | label: "clippy::fn_to_numeric_cast", |
4968 | description: r##"Checks for casts of function pointers to something other than usize"##, | 5515 | description: r##"Checks for casts of function pointers to something other than usize"##, |
4969 | }, | 5516 | }, |
4970 | LintCompletion { | 5517 | Lint { |
4971 | label: "clippy::fn_to_numeric_cast_with_truncation", | 5518 | label: "clippy::fn_to_numeric_cast_with_truncation", |
4972 | description: r##"Checks for casts of a function pointer to a numeric type not wide enough to\nstore address."##, | 5519 | description: r##"Checks for casts of a function pointer to a numeric type not wide enough to\nstore address."##, |
4973 | }, | 5520 | }, |
4974 | LintCompletion { | 5521 | Lint { |
4975 | label: "clippy::for_kv_map", | 5522 | label: "clippy::for_kv_map", |
4976 | description: r##"Checks for iterating a map (`HashMap` or `BTreeMap`) and\nignoring either the keys or values."##, | 5523 | description: r##"Checks for iterating a map (`HashMap` or `BTreeMap`) and\nignoring either the keys or values."##, |
4977 | }, | 5524 | }, |
4978 | LintCompletion { | 5525 | Lint { |
4979 | label: "clippy::for_loops_over_fallibles", | 5526 | label: "clippy::for_loops_over_fallibles", |
4980 | description: r##"Checks for `for` loops over `Option` or `Result` values."##, | 5527 | description: r##"Checks for `for` loops over `Option` or `Result` values."##, |
4981 | }, | 5528 | }, |
4982 | LintCompletion { | 5529 | Lint { |
4983 | label: "clippy::forget_copy", | 5530 | label: "clippy::forget_copy", |
4984 | description: r##"Checks for calls to `std::mem::forget` with a value that\nderives the Copy trait"##, | 5531 | description: r##"Checks for calls to `std::mem::forget` with a value that\nderives the Copy trait"##, |
4985 | }, | 5532 | }, |
4986 | LintCompletion { | 5533 | Lint { |
4987 | label: "clippy::forget_ref", | 5534 | label: "clippy::forget_ref", |
4988 | description: r##"Checks for calls to `std::mem::forget` with a reference\ninstead of an owned value."##, | 5535 | description: r##"Checks for calls to `std::mem::forget` with a reference\ninstead of an owned value."##, |
4989 | }, | 5536 | }, |
4990 | LintCompletion { | 5537 | Lint { |
4991 | label: "clippy::from_iter_instead_of_collect", | 5538 | label: "clippy::from_iter_instead_of_collect", |
4992 | description: r##"Checks for `from_iter()` function calls on types that implement the `FromIterator`\ntrait."##, | 5539 | description: r##"Checks for `from_iter()` function calls on types that implement the `FromIterator`\ntrait."##, |
4993 | }, | 5540 | }, |
4994 | LintCompletion { | 5541 | Lint { |
4995 | label: "clippy::from_over_into", | 5542 | label: "clippy::from_over_into", |
4996 | description: r##"Searches for implementations of the `Into<..>` trait and suggests to implement `From<..>` instead."##, | 5543 | description: r##"Searches for implementations of the `Into<..>` trait and suggests to implement `From<..>` instead."##, |
4997 | }, | 5544 | }, |
4998 | LintCompletion { | 5545 | Lint { |
4999 | label: "clippy::from_str_radix_10", | 5546 | label: "clippy::from_str_radix_10", |
5000 | description: r##"Checks for function invocations of the form `primitive::from_str_radix(s, 10)`"##, | 5547 | description: r##"Checks for function invocations of the form `primitive::from_str_radix(s, 10)`"##, |
5001 | }, | 5548 | }, |
5002 | LintCompletion { | 5549 | Lint { |
5003 | label: "clippy::future_not_send", | 5550 | label: "clippy::future_not_send", |
5004 | description: r##"This lint requires Future implementations returned from\nfunctions and methods to implement the `Send` marker trait. It is mostly\nused by library authors (public and internal) that target an audience where\nmultithreaded executors are likely to be used for running these Futures."##, | 5551 | description: r##"This lint requires Future implementations returned from\nfunctions and methods to implement the `Send` marker trait. It is mostly\nused by library authors (public and internal) that target an audience where\nmultithreaded executors are likely to be used for running these Futures."##, |
5005 | }, | 5552 | }, |
5006 | LintCompletion { | 5553 | Lint { |
5007 | label: "clippy::get_last_with_len", | 5554 | label: "clippy::get_last_with_len", |
5008 | description: r##"Checks for using `x.get(x.len() - 1)` instead of\n`x.last()`."##, | 5555 | description: r##"Checks for using `x.get(x.len() - 1)` instead of\n`x.last()`."##, |
5009 | }, | 5556 | }, |
5010 | LintCompletion { | 5557 | Lint { |
5011 | label: "clippy::get_unwrap", | 5558 | label: "clippy::get_unwrap", |
5012 | description: r##"Checks for use of `.get().unwrap()` (or\n`.get_mut().unwrap`) on a standard library type which implements `Index`"##, | 5559 | description: r##"Checks for use of `.get().unwrap()` (or\n`.get_mut().unwrap`) on a standard library type which implements `Index`"##, |
5013 | }, | 5560 | }, |
5014 | LintCompletion { | 5561 | Lint { |
5015 | label: "clippy::identity_op", | 5562 | label: "clippy::identity_op", |
5016 | description: r##"Checks for identity operations, e.g., `x + 0`."##, | 5563 | description: r##"Checks for identity operations, e.g., `x + 0`."##, |
5017 | }, | 5564 | }, |
5018 | LintCompletion { | 5565 | Lint { |
5019 | label: "clippy::if_let_mutex", | 5566 | label: "clippy::if_let_mutex", |
5020 | description: r##"Checks for `Mutex::lock` calls in `if let` expression\nwith lock calls in any of the else blocks."##, | 5567 | description: r##"Checks for `Mutex::lock` calls in `if let` expression\nwith lock calls in any of the else blocks."##, |
5021 | }, | 5568 | }, |
5022 | LintCompletion { | 5569 | Lint { |
5023 | label: "clippy::if_let_redundant_pattern_matching", | 5570 | label: "clippy::if_let_redundant_pattern_matching", |
5024 | description: r##"Nothing. This lint has been deprecated."##, | 5571 | description: r##"Nothing. This lint has been deprecated."##, |
5025 | }, | 5572 | }, |
5026 | LintCompletion { | 5573 | Lint { |
5027 | label: "clippy::if_let_some_result", | 5574 | label: "clippy::if_let_some_result", |
5028 | description: r##"* Checks for unnecessary `ok()` in if let."##, | 5575 | description: r##"* Checks for unnecessary `ok()` in if let."##, |
5029 | }, | 5576 | }, |
5030 | LintCompletion { | 5577 | Lint { |
5031 | label: "clippy::if_not_else", | 5578 | label: "clippy::if_not_else", |
5032 | description: r##"Checks for usage of `!` or `!=` in an if condition with an\nelse branch."##, | 5579 | description: r##"Checks for usage of `!` or `!=` in an if condition with an\nelse branch."##, |
5033 | }, | 5580 | }, |
5034 | LintCompletion { | 5581 | Lint { |
5035 | label: "clippy::if_same_then_else", | 5582 | label: "clippy::if_same_then_else", |
5036 | description: r##"Checks for `if/else` with the same body as the *then* part\nand the *else* part."##, | 5583 | description: r##"Checks for `if/else` with the same body as the *then* part\nand the *else* part."##, |
5037 | }, | 5584 | }, |
5038 | LintCompletion { | 5585 | Lint { |
5586 | label: "clippy::if_then_some_else_none", | ||
5587 | description: r##"Checks for if-else that could be written to `bool::then`."##, | ||
5588 | }, | ||
5589 | Lint { | ||
5039 | label: "clippy::ifs_same_cond", | 5590 | label: "clippy::ifs_same_cond", |
5040 | description: r##"Checks for consecutive `if`s with the same condition."##, | 5591 | description: r##"Checks for consecutive `if`s with the same condition."##, |
5041 | }, | 5592 | }, |
5042 | LintCompletion { | 5593 | Lint { |
5043 | label: "clippy::implicit_clone", | 5594 | label: "clippy::implicit_clone", |
5044 | description: r##"Checks for the usage of `_.to_owned()`, `vec.to_vec()`, or similar when calling `_.clone()` would be clearer."##, | 5595 | description: r##"Checks for the usage of `_.to_owned()`, `vec.to_vec()`, or similar when calling `_.clone()` would be clearer."##, |
5045 | }, | 5596 | }, |
5046 | LintCompletion { | 5597 | Lint { |
5047 | label: "clippy::implicit_hasher", | 5598 | label: "clippy::implicit_hasher", |
5048 | description: r##"Checks for public `impl` or `fn` missing generalization\nover different hashers and implicitly defaulting to the default hashing\nalgorithm (`SipHash`)."##, | 5599 | description: r##"Checks for public `impl` or `fn` missing generalization\nover different hashers and implicitly defaulting to the default hashing\nalgorithm (`SipHash`)."##, |
5049 | }, | 5600 | }, |
5050 | LintCompletion { | 5601 | Lint { |
5051 | label: "clippy::implicit_return", | 5602 | label: "clippy::implicit_return", |
5052 | description: r##"Checks for missing return statements at the end of a block."##, | 5603 | description: r##"Checks for missing return statements at the end of a block."##, |
5053 | }, | 5604 | }, |
5054 | LintCompletion { | 5605 | Lint { |
5055 | label: "clippy::implicit_saturating_sub", | 5606 | label: "clippy::implicit_saturating_sub", |
5056 | description: r##"Checks for implicit saturating subtraction."##, | 5607 | description: r##"Checks for implicit saturating subtraction."##, |
5057 | }, | 5608 | }, |
5058 | LintCompletion { | 5609 | Lint { |
5059 | label: "clippy::imprecise_flops", | 5610 | label: "clippy::imprecise_flops", |
5060 | description: r##"Looks for floating-point expressions that\ncan be expressed using built-in methods to improve accuracy\nat the cost of performance."##, | 5611 | description: r##"Looks for floating-point expressions that\ncan be expressed using built-in methods to improve accuracy\nat the cost of performance."##, |
5061 | }, | 5612 | }, |
5062 | LintCompletion { | 5613 | Lint { |
5063 | label: "clippy::inconsistent_digit_grouping", | 5614 | label: "clippy::inconsistent_digit_grouping", |
5064 | description: r##"Warns if an integral or floating-point constant is\ngrouped inconsistently with underscores."##, | 5615 | description: r##"Warns if an integral or floating-point constant is\ngrouped inconsistently with underscores."##, |
5065 | }, | 5616 | }, |
5066 | LintCompletion { | 5617 | Lint { |
5067 | label: "clippy::inconsistent_struct_constructor", | 5618 | label: "clippy::inconsistent_struct_constructor", |
5068 | description: r##"Checks for struct constructors where the order of the field init\nshorthand in the constructor is inconsistent with the order in the struct definition."##, | 5619 | description: r##"Checks for struct constructors where all fields are shorthand and\nthe order of the field init shorthand in the constructor is inconsistent\nwith the order in the struct definition."##, |
5069 | }, | 5620 | }, |
5070 | LintCompletion { | 5621 | Lint { |
5071 | label: "clippy::indexing_slicing", | 5622 | label: "clippy::indexing_slicing", |
5072 | description: r##"Checks for usage of indexing or slicing. Arrays are special cases, this lint\ndoes report on arrays if we can tell that slicing operations are in bounds and does not\nlint on constant `usize` indexing on arrays because that is handled by rustc's `const_err` lint."##, | 5623 | description: r##"Checks for usage of indexing or slicing. Arrays are special cases, this lint\ndoes report on arrays if we can tell that slicing operations are in bounds and does not\nlint on constant `usize` indexing on arrays because that is handled by rustc's `const_err` lint."##, |
5073 | }, | 5624 | }, |
5074 | LintCompletion { | 5625 | Lint { |
5075 | label: "clippy::ineffective_bit_mask", | 5626 | label: "clippy::ineffective_bit_mask", |
5076 | description: r##"Checks for bit masks in comparisons which can be removed\nwithout changing the outcome. The basic structure can be seen in the\nfollowing table:\n\n|Comparison| Bit Op |Example |equals |\n|----------|---------|-----------|-------|\n|`>` / `<=`|`|` / `^`|`x | 2 > 3`|`x > 3`|\n|`<` / `>=`|`|` / `^`|`x ^ 1 < 4`|`x < 4`|"##, | 5627 | description: r##"Checks for bit masks in comparisons which can be removed\nwithout changing the outcome. The basic structure can be seen in the\nfollowing table:\n\n|Comparison| Bit Op |Example |equals |\n|----------|---------|-----------|-------|\n|`>` / `<=`|`|` / `^`|`x | 2 > 3`|`x > 3`|\n|`<` / `>=`|`|` / `^`|`x ^ 1 < 4`|`x < 4`|"##, |
5077 | }, | 5628 | }, |
5078 | LintCompletion { | 5629 | Lint { |
5079 | label: "clippy::inefficient_to_string", | 5630 | label: "clippy::inefficient_to_string", |
5080 | description: r##"Checks for usage of `.to_string()` on an `&&T` where\n`T` implements `ToString` directly (like `&&str` or `&&String`)."##, | 5631 | description: r##"Checks for usage of `.to_string()` on an `&&T` where\n`T` implements `ToString` directly (like `&&str` or `&&String`)."##, |
5081 | }, | 5632 | }, |
5082 | LintCompletion { | 5633 | Lint { |
5083 | label: "clippy::infallible_destructuring_match", | 5634 | label: "clippy::infallible_destructuring_match", |
5084 | description: r##"Checks for matches being used to destructure a single-variant enum\nor tuple struct where a `let` will suffice."##, | 5635 | description: r##"Checks for matches being used to destructure a single-variant enum\nor tuple struct where a `let` will suffice."##, |
5085 | }, | 5636 | }, |
5086 | LintCompletion { | 5637 | Lint { |
5087 | label: "clippy::infinite_iter", | 5638 | label: "clippy::infinite_iter", |
5088 | description: r##"Checks for iteration that is guaranteed to be infinite."##, | 5639 | description: r##"Checks for iteration that is guaranteed to be infinite."##, |
5089 | }, | 5640 | }, |
5090 | LintCompletion { | 5641 | Lint { |
5091 | label: "clippy::inherent_to_string", | 5642 | label: "clippy::inherent_to_string", |
5092 | description: r##"Checks for the definition of inherent methods with a signature of `to_string(&self) -> String`."##, | 5643 | description: r##"Checks for the definition of inherent methods with a signature of `to_string(&self) -> String`."##, |
5093 | }, | 5644 | }, |
5094 | LintCompletion { | 5645 | Lint { |
5095 | label: "clippy::inherent_to_string_shadow_display", | 5646 | label: "clippy::inherent_to_string_shadow_display", |
5096 | description: r##"Checks for the definition of inherent methods with a signature of `to_string(&self) -> String` and if the type implementing this method also implements the `Display` trait."##, | 5647 | description: r##"Checks for the definition of inherent methods with a signature of `to_string(&self) -> String` and if the type implementing this method also implements the `Display` trait."##, |
5097 | }, | 5648 | }, |
5098 | LintCompletion { | 5649 | Lint { |
5099 | label: "clippy::inline_always", | 5650 | label: "clippy::inline_always", |
5100 | description: r##"Checks for items annotated with `#[inline(always)]`,\nunless the annotated function is empty or simply panics."##, | 5651 | description: r##"Checks for items annotated with `#[inline(always)]`,\nunless the annotated function is empty or simply panics."##, |
5101 | }, | 5652 | }, |
5102 | LintCompletion { | 5653 | Lint { |
5103 | label: "clippy::inline_asm_x86_att_syntax", | 5654 | label: "clippy::inline_asm_x86_att_syntax", |
5104 | description: r##"Checks for usage of AT&T x86 assembly syntax."##, | 5655 | description: r##"Checks for usage of AT&T x86 assembly syntax."##, |
5105 | }, | 5656 | }, |
5106 | LintCompletion { | 5657 | Lint { |
5107 | label: "clippy::inline_asm_x86_intel_syntax", | 5658 | label: "clippy::inline_asm_x86_intel_syntax", |
5108 | description: r##"Checks for usage of Intel x86 assembly syntax."##, | 5659 | description: r##"Checks for usage of Intel x86 assembly syntax."##, |
5109 | }, | 5660 | }, |
5110 | LintCompletion { | 5661 | Lint { |
5111 | label: "clippy::inline_fn_without_body", | 5662 | label: "clippy::inline_fn_without_body", |
5112 | description: r##"Checks for `#[inline]` on trait methods without bodies"##, | 5663 | description: r##"Checks for `#[inline]` on trait methods without bodies"##, |
5113 | }, | 5664 | }, |
5114 | LintCompletion { | 5665 | Lint { |
5115 | label: "clippy::inspect_for_each", | 5666 | label: "clippy::inspect_for_each", |
5116 | description: r##"Checks for usage of `inspect().for_each()`."##, | 5667 | description: r##"Checks for usage of `inspect().for_each()`."##, |
5117 | }, | 5668 | }, |
5118 | LintCompletion { | 5669 | Lint { |
5119 | label: "clippy::int_plus_one", | 5670 | label: "clippy::int_plus_one", |
5120 | description: r##"Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block"##, | 5671 | description: r##"Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block"##, |
5121 | }, | 5672 | }, |
5122 | LintCompletion { | 5673 | Lint { |
5123 | label: "clippy::integer_arithmetic", | 5674 | label: "clippy::integer_arithmetic", |
5124 | description: r##"Checks for integer arithmetic operations which could overflow or panic.\n\nSpecifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable\nof overflowing according to the [Rust\nReference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),\nor which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is\nattempted."##, | 5675 | description: r##"Checks for integer arithmetic operations which could overflow or panic.\n\nSpecifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable\nof overflowing according to the [Rust\nReference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),\nor which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is\nattempted."##, |
5125 | }, | 5676 | }, |
5126 | LintCompletion { | 5677 | Lint { label: "clippy::integer_division", description: r##"Checks for division of integers"## }, |
5127 | label: "clippy::integer_division", | 5678 | Lint { |
5128 | description: r##"Checks for division of integers"##, | ||
5129 | }, | ||
5130 | LintCompletion { | ||
5131 | label: "clippy::into_iter_on_array", | ||
5132 | description: r##"Nothing. This lint has been deprecated."##, | ||
5133 | }, | ||
5134 | LintCompletion { | ||
5135 | label: "clippy::into_iter_on_ref", | 5679 | label: "clippy::into_iter_on_ref", |
5136 | description: r##"Checks for `into_iter` calls on references which should be replaced by `iter`\nor `iter_mut`."##, | 5680 | description: r##"Checks for `into_iter` calls on references which should be replaced by `iter`\nor `iter_mut`."##, |
5137 | }, | 5681 | }, |
5138 | LintCompletion { | 5682 | Lint { |
5139 | label: "clippy::invalid_atomic_ordering", | 5683 | label: "clippy::invalid_atomic_ordering", |
5140 | description: r##"Checks for usage of invalid atomic\nordering in atomic loads/stores/exchanges/updates and\nmemory fences."##, | 5684 | description: r##"Checks for usage of invalid atomic\nordering in atomic loads/stores/exchanges/updates and\nmemory fences."##, |
5141 | }, | 5685 | }, |
5142 | LintCompletion { | 5686 | Lint { |
5143 | label: "clippy::invalid_ref", | 5687 | label: "clippy::invalid_null_ptr_usage", |
5144 | description: r##"Nothing. This lint has been deprecated."##, | 5688 | description: r##"This lint checks for invalid usages of `ptr::null`."##, |
5145 | }, | 5689 | }, |
5146 | LintCompletion { | 5690 | Lint { |
5147 | label: "clippy::invalid_regex", | 5691 | label: "clippy::invalid_regex", |
5148 | description: r##"Checks [regex](https://crates.io/crates/regex) creation\n(with `Regex::new`, `RegexBuilder::new`, or `RegexSet::new`) for correct\nregex syntax."##, | 5692 | description: r##"Checks [regex](https://crates.io/crates/regex) creation\n(with `Regex::new`, `RegexBuilder::new`, or `RegexSet::new`) for correct\nregex syntax."##, |
5149 | }, | 5693 | }, |
5150 | LintCompletion { | 5694 | Lint { |
5151 | label: "clippy::invalid_upcast_comparisons", | 5695 | label: "clippy::invalid_upcast_comparisons", |
5152 | description: r##"Checks for comparisons where the relation is always either\ntrue or false, but where one side has been upcast so that the comparison is\nnecessary. Only integer types are checked."##, | 5696 | description: r##"Checks for comparisons where the relation is always either\ntrue or false, but where one side has been upcast so that the comparison is\nnecessary. Only integer types are checked."##, |
5153 | }, | 5697 | }, |
5154 | LintCompletion { | 5698 | Lint { |
5155 | label: "clippy::invisible_characters", | 5699 | label: "clippy::invisible_characters", |
5156 | description: r##"Checks for invisible Unicode characters in the code."##, | 5700 | description: r##"Checks for invisible Unicode characters in the code."##, |
5157 | }, | 5701 | }, |
5158 | LintCompletion { | 5702 | Lint { |
5159 | label: "clippy::items_after_statements", | 5703 | label: "clippy::items_after_statements", |
5160 | description: r##"Checks for items declared after some statement in a block."##, | 5704 | description: r##"Checks for items declared after some statement in a block."##, |
5161 | }, | 5705 | }, |
5162 | LintCompletion { | 5706 | Lint { |
5163 | label: "clippy::iter_cloned_collect", | 5707 | label: "clippy::iter_cloned_collect", |
5164 | description: r##"Checks for the use of `.cloned().collect()` on slice to\ncreate a `Vec`."##, | 5708 | description: r##"Checks for the use of `.cloned().collect()` on slice to\ncreate a `Vec`."##, |
5165 | }, | 5709 | }, |
5166 | LintCompletion { | 5710 | Lint { |
5167 | label: "clippy::iter_next_loop", | 5711 | label: "clippy::iter_count", |
5168 | description: r##"Checks for loops on `x.next()`."##, | 5712 | description: r##"Checks for the use of `.iter().count()`."##, |
5169 | }, | 5713 | }, |
5170 | LintCompletion { | 5714 | Lint { label: "clippy::iter_next_loop", description: r##"Checks for loops on `x.next()`."## }, |
5715 | Lint { | ||
5171 | label: "clippy::iter_next_slice", | 5716 | label: "clippy::iter_next_slice", |
5172 | description: r##"Checks for usage of `iter().next()` on a Slice or an Array"##, | 5717 | description: r##"Checks for usage of `iter().next()` on a Slice or an Array"##, |
5173 | }, | 5718 | }, |
5174 | LintCompletion { | 5719 | Lint { |
5175 | label: "clippy::iter_nth", | 5720 | label: "clippy::iter_nth", |
5176 | description: r##"Checks for use of `.iter().nth()` (and the related\n`.iter_mut().nth()`) on standard library types with O(1) element access."##, | 5721 | description: r##"Checks for use of `.iter().nth()` (and the related\n`.iter_mut().nth()`) on standard library types with O(1) element access."##, |
5177 | }, | 5722 | }, |
5178 | LintCompletion { | 5723 | Lint { |
5179 | label: "clippy::iter_nth_zero", | 5724 | label: "clippy::iter_nth_zero", |
5180 | description: r##"Checks for the use of `iter.nth(0)`."##, | 5725 | description: r##"Checks for the use of `iter.nth(0)`."##, |
5181 | }, | 5726 | }, |
5182 | LintCompletion { | 5727 | Lint { |
5183 | label: "clippy::iter_skip_next", | 5728 | label: "clippy::iter_skip_next", |
5184 | description: r##"Checks for use of `.skip(x).next()` on iterators."##, | 5729 | description: r##"Checks for use of `.skip(x).next()` on iterators."##, |
5185 | }, | 5730 | }, |
5186 | LintCompletion { | 5731 | Lint { |
5187 | label: "clippy::iterator_step_by_zero", | 5732 | label: "clippy::iterator_step_by_zero", |
5188 | description: r##"Checks for calling `.step_by(0)` on iterators which panics."##, | 5733 | description: r##"Checks for calling `.step_by(0)` on iterators which panics."##, |
5189 | }, | 5734 | }, |
5190 | LintCompletion { | 5735 | Lint { |
5191 | label: "clippy::just_underscores_and_digits", | 5736 | label: "clippy::just_underscores_and_digits", |
5192 | description: r##"Checks if you have variables whose name consists of just\nunderscores and digits."##, | 5737 | description: r##"Checks if you have variables whose name consists of just\nunderscores and digits."##, |
5193 | }, | 5738 | }, |
5194 | LintCompletion { | 5739 | Lint { |
5195 | label: "clippy::large_const_arrays", | 5740 | label: "clippy::large_const_arrays", |
5196 | description: r##"Checks for large `const` arrays that should\nbe defined as `static` instead."##, | 5741 | description: r##"Checks for large `const` arrays that should\nbe defined as `static` instead."##, |
5197 | }, | 5742 | }, |
5198 | LintCompletion { | 5743 | Lint { |
5199 | label: "clippy::large_digit_groups", | 5744 | label: "clippy::large_digit_groups", |
5200 | description: r##"Warns if the digits of an integral or floating-point\nconstant are grouped into groups that\nare too large."##, | 5745 | description: r##"Warns if the digits of an integral or floating-point\nconstant are grouped into groups that\nare too large."##, |
5201 | }, | 5746 | }, |
5202 | LintCompletion { | 5747 | Lint { |
5203 | label: "clippy::large_enum_variant", | 5748 | label: "clippy::large_enum_variant", |
5204 | description: r##"Checks for large size differences between variants on\n`enum`s."##, | 5749 | description: r##"Checks for large size differences between variants on\n`enum`s."##, |
5205 | }, | 5750 | }, |
5206 | LintCompletion { | 5751 | Lint { |
5207 | label: "clippy::large_stack_arrays", | 5752 | label: "clippy::large_stack_arrays", |
5208 | description: r##"Checks for local arrays that may be too large."##, | 5753 | description: r##"Checks for local arrays that may be too large."##, |
5209 | }, | 5754 | }, |
5210 | LintCompletion { | 5755 | Lint { |
5211 | label: "clippy::large_types_passed_by_value", | 5756 | label: "clippy::large_types_passed_by_value", |
5212 | description: r##"Checks for functions taking arguments by value, where\nthe argument type is `Copy` and large enough to be worth considering\npassing by reference. Does not trigger if the function is being exported,\nbecause that might induce API breakage, if the parameter is declared as mutable,\nor if the argument is a `self`."##, | 5757 | description: r##"Checks for functions taking arguments by value, where\nthe argument type is `Copy` and large enough to be worth considering\npassing by reference. Does not trigger if the function is being exported,\nbecause that might induce API breakage, if the parameter is declared as mutable,\nor if the argument is a `self`."##, |
5213 | }, | 5758 | }, |
5214 | LintCompletion { | 5759 | Lint { |
5215 | label: "clippy::len_without_is_empty", | 5760 | label: "clippy::len_without_is_empty", |
5216 | description: r##"Checks for items that implement `.len()` but not\n`.is_empty()`."##, | 5761 | description: r##"Checks for items that implement `.len()` but not\n`.is_empty()`."##, |
5217 | }, | 5762 | }, |
5218 | LintCompletion { | 5763 | Lint { |
5219 | label: "clippy::len_zero", | 5764 | label: "clippy::len_zero", |
5220 | description: r##"Checks for getting the length of something via `.len()`\njust to compare to zero, and suggests using `.is_empty()` where applicable."##, | 5765 | description: r##"Checks for getting the length of something via `.len()`\njust to compare to zero, and suggests using `.is_empty()` where applicable."##, |
5221 | }, | 5766 | }, |
5222 | LintCompletion { | 5767 | Lint { |
5223 | label: "clippy::let_and_return", | 5768 | label: "clippy::let_and_return", |
5224 | description: r##"Checks for `let`-bindings, which are subsequently\nreturned."##, | 5769 | description: r##"Checks for `let`-bindings, which are subsequently\nreturned."##, |
5225 | }, | 5770 | }, |
5226 | LintCompletion { | 5771 | Lint { |
5227 | label: "clippy::let_underscore_drop", | 5772 | label: "clippy::let_underscore_drop", |
5228 | description: r##"Checks for `let _ = <expr>`\nwhere expr has a type that implements `Drop`"##, | 5773 | description: r##"Checks for `let _ = <expr>`\nwhere expr has a type that implements `Drop`"##, |
5229 | }, | 5774 | }, |
5230 | LintCompletion { | 5775 | Lint { |
5231 | label: "clippy::let_underscore_lock", | 5776 | label: "clippy::let_underscore_lock", |
5232 | description: r##"Checks for `let _ = sync_lock`"##, | 5777 | description: r##"Checks for `let _ = sync_lock`"##, |
5233 | }, | 5778 | }, |
5234 | LintCompletion { | 5779 | Lint { |
5235 | label: "clippy::let_underscore_must_use", | 5780 | label: "clippy::let_underscore_must_use", |
5236 | description: r##"Checks for `let _ = <expr>`\nwhere expr is #[must_use]"##, | 5781 | description: r##"Checks for `let _ = <expr>`\nwhere expr is #[must_use]"##, |
5237 | }, | 5782 | }, |
5238 | LintCompletion { | 5783 | Lint { label: "clippy::let_unit_value", description: r##"Checks for binding a unit value."## }, |
5239 | label: "clippy::let_unit_value", | 5784 | Lint { |
5240 | description: r##"Checks for binding a unit value."##, | ||
5241 | }, | ||
5242 | LintCompletion { | ||
5243 | label: "clippy::linkedlist", | 5785 | label: "clippy::linkedlist", |
5244 | description: r##"Checks for usage of any `LinkedList`, suggesting to use a\n`Vec` or a `VecDeque` (formerly called `RingBuf`)."##, | 5786 | description: r##"Checks for usage of any `LinkedList`, suggesting to use a\n`Vec` or a `VecDeque` (formerly called `RingBuf`)."##, |
5245 | }, | 5787 | }, |
5246 | LintCompletion { | 5788 | Lint { |
5247 | label: "clippy::logic_bug", | 5789 | label: "clippy::logic_bug", |
5248 | description: r##"Checks for boolean expressions that contain terminals that\ncan be eliminated."##, | 5790 | description: r##"Checks for boolean expressions that contain terminals that\ncan be eliminated."##, |
5249 | }, | 5791 | }, |
5250 | LintCompletion { | 5792 | Lint { |
5251 | label: "clippy::lossy_float_literal", | 5793 | label: "clippy::lossy_float_literal", |
5252 | description: r##"Checks for whole number float literals that\ncannot be represented as the underlying type without loss."##, | 5794 | description: r##"Checks for whole number float literals that\ncannot be represented as the underlying type without loss."##, |
5253 | }, | 5795 | }, |
5254 | LintCompletion { | 5796 | Lint { |
5255 | label: "clippy::macro_use_imports", | 5797 | label: "clippy::macro_use_imports", |
5256 | description: r##"Checks for `#[macro_use] use...`."##, | 5798 | description: r##"Checks for `#[macro_use] use...`."##, |
5257 | }, | 5799 | }, |
5258 | LintCompletion { | 5800 | Lint { |
5259 | label: "clippy::main_recursion", | 5801 | label: "clippy::main_recursion", |
5260 | description: r##"Checks for recursion using the entrypoint."##, | 5802 | description: r##"Checks for recursion using the entrypoint."##, |
5261 | }, | 5803 | }, |
5262 | LintCompletion { | 5804 | Lint { |
5263 | label: "clippy::manual_async_fn", | 5805 | label: "clippy::manual_async_fn", |
5264 | description: r##"It checks for manual implementations of `async` functions."##, | 5806 | description: r##"It checks for manual implementations of `async` functions."##, |
5265 | }, | 5807 | }, |
5266 | LintCompletion { | 5808 | Lint { |
5267 | label: "clippy::manual_filter_map", | 5809 | label: "clippy::manual_filter_map", |
5268 | description: r##"Checks for usage of `_.filter(_).map(_)` that can be written more simply\nas `filter_map(_)`."##, | 5810 | description: r##"Checks for usage of `_.filter(_).map(_)` that can be written more simply\nas `filter_map(_)`."##, |
5269 | }, | 5811 | }, |
5270 | LintCompletion { | 5812 | Lint { |
5271 | label: "clippy::manual_find_map", | 5813 | label: "clippy::manual_find_map", |
5272 | description: r##"Checks for usage of `_.find(_).map(_)` that can be written more simply\nas `find_map(_)`."##, | 5814 | description: r##"Checks for usage of `_.find(_).map(_)` that can be written more simply\nas `find_map(_)`."##, |
5273 | }, | 5815 | }, |
5274 | LintCompletion { | 5816 | Lint { |
5275 | label: "clippy::manual_flatten", | 5817 | label: "clippy::manual_flatten", |
5276 | description: r##"Check for unnecessary `if let` usage in a for loop\nwhere only the `Some` or `Ok` variant of the iterator element is used."##, | 5818 | description: r##"Check for unnecessary `if let` usage in a for loop\nwhere only the `Some` or `Ok` variant of the iterator element is used."##, |
5277 | }, | 5819 | }, |
5278 | LintCompletion { | 5820 | Lint { |
5279 | label: "clippy::manual_map", | 5821 | label: "clippy::manual_map", |
5280 | description: r##"Checks for usages of `match` which could be implemented using `map`"##, | 5822 | description: r##"Checks for usages of `match` which could be implemented using `map`"##, |
5281 | }, | 5823 | }, |
5282 | LintCompletion { | 5824 | Lint { |
5283 | label: "clippy::manual_memcpy", | 5825 | label: "clippy::manual_memcpy", |
5284 | description: r##"Checks for for-loops that manually copy items between\nslices that could be optimized by having a memcpy."##, | 5826 | description: r##"Checks for for-loops that manually copy items between\nslices that could be optimized by having a memcpy."##, |
5285 | }, | 5827 | }, |
5286 | LintCompletion { | 5828 | Lint { |
5287 | label: "clippy::manual_non_exhaustive", | 5829 | label: "clippy::manual_non_exhaustive", |
5288 | description: r##"Checks for manual implementations of the non-exhaustive pattern."##, | 5830 | description: r##"Checks for manual implementations of the non-exhaustive pattern."##, |
5289 | }, | 5831 | }, |
5290 | LintCompletion { | 5832 | Lint { |
5291 | label: "clippy::manual_ok_or", | 5833 | label: "clippy::manual_ok_or", |
5292 | description: r##"Finds patterns that reimplement `Option::ok_or`."##, | 5834 | description: r##"Finds patterns that reimplement `Option::ok_or`."##, |
5293 | }, | 5835 | }, |
5294 | LintCompletion { | 5836 | Lint { |
5295 | label: "clippy::manual_range_contains", | 5837 | label: "clippy::manual_range_contains", |
5296 | description: r##"Checks for expressions like `x >= 3 && x < 8` that could\nbe more readably expressed as `(3..8).contains(x)`."##, | 5838 | description: r##"Checks for expressions like `x >= 3 && x < 8` that could\nbe more readably expressed as `(3..8).contains(x)`."##, |
5297 | }, | 5839 | }, |
5298 | LintCompletion { | 5840 | Lint { |
5299 | label: "clippy::manual_saturating_arithmetic", | 5841 | label: "clippy::manual_saturating_arithmetic", |
5300 | description: r##"Checks for `.checked_add/sub(x).unwrap_or(MAX/MIN)`."##, | 5842 | description: r##"Checks for `.checked_add/sub(x).unwrap_or(MAX/MIN)`."##, |
5301 | }, | 5843 | }, |
5302 | LintCompletion { | 5844 | Lint { |
5845 | label: "clippy::manual_str_repeat", | ||
5846 | description: r##"Checks for manual implementations of `str::repeat`"##, | ||
5847 | }, | ||
5848 | Lint { | ||
5303 | label: "clippy::manual_strip", | 5849 | label: "clippy::manual_strip", |
5304 | description: r##"Suggests using `strip_{prefix,suffix}` over `str::{starts,ends}_with` and slicing using\nthe pattern's length."##, | 5850 | description: r##"Suggests using `strip_{prefix,suffix}` over `str::{starts,ends}_with` and slicing using\nthe pattern's length."##, |
5305 | }, | 5851 | }, |
5306 | LintCompletion { | 5852 | Lint { label: "clippy::manual_swap", description: r##"Checks for manual swapping."## }, |
5307 | label: "clippy::manual_swap", | 5853 | Lint { |
5308 | description: r##"Checks for manual swapping."##, | ||
5309 | }, | ||
5310 | LintCompletion { | ||
5311 | label: "clippy::manual_unwrap_or", | 5854 | label: "clippy::manual_unwrap_or", |
5312 | description: r##"Finds patterns that reimplement `Option::unwrap_or` or `Result::unwrap_or`."##, | 5855 | description: r##"Finds patterns that reimplement `Option::unwrap_or` or `Result::unwrap_or`."##, |
5313 | }, | 5856 | }, |
5314 | LintCompletion { | 5857 | Lint { |
5315 | label: "clippy::many_single_char_names", | 5858 | label: "clippy::many_single_char_names", |
5316 | description: r##"Checks for too many variables whose name consists of a\nsingle character."##, | 5859 | description: r##"Checks for too many variables whose name consists of a\nsingle character."##, |
5317 | }, | 5860 | }, |
5318 | LintCompletion { | 5861 | Lint { |
5319 | label: "clippy::map_clone", | 5862 | label: "clippy::map_clone", |
5320 | description: r##"Checks for usage of `map(|x| x.clone())` or\ndereferencing closures for `Copy` types, on `Iterator` or `Option`,\nand suggests `cloned()` or `copied()` instead"##, | 5863 | description: r##"Checks for usage of `map(|x| x.clone())` or\ndereferencing closures for `Copy` types, on `Iterator` or `Option`,\nand suggests `cloned()` or `copied()` instead"##, |
5321 | }, | 5864 | }, |
5322 | LintCompletion { | 5865 | Lint { |
5323 | label: "clippy::map_collect_result_unit", | 5866 | label: "clippy::map_collect_result_unit", |
5324 | description: r##"Checks for usage of `_.map(_).collect::<Result<(), _>()`."##, | 5867 | description: r##"Checks for usage of `_.map(_).collect::<Result<(), _>()`."##, |
5325 | }, | 5868 | }, |
5326 | LintCompletion { | 5869 | Lint { |
5327 | label: "clippy::map_entry", | 5870 | label: "clippy::map_entry", |
5328 | description: r##"Checks for uses of `contains_key` + `insert` on `HashMap`\nor `BTreeMap`."##, | 5871 | description: r##"Checks for uses of `contains_key` + `insert` on `HashMap`\nor `BTreeMap`."##, |
5329 | }, | 5872 | }, |
5330 | LintCompletion { | 5873 | Lint { |
5331 | label: "clippy::map_err_ignore", | 5874 | label: "clippy::map_err_ignore", |
5332 | description: r##"Checks for instances of `map_err(|_| Some::Enum)`"##, | 5875 | description: r##"Checks for instances of `map_err(|_| Some::Enum)`"##, |
5333 | }, | 5876 | }, |
5334 | LintCompletion { | 5877 | Lint { |
5335 | label: "clippy::map_flatten", | 5878 | label: "clippy::map_flatten", |
5336 | description: r##"Checks for usage of `_.map(_).flatten(_)`,"##, | 5879 | description: r##"Checks for usage of `_.map(_).flatten(_)` on `Iterator` and `Option`"##, |
5337 | }, | 5880 | }, |
5338 | LintCompletion { | 5881 | Lint { |
5339 | label: "clippy::map_identity", | 5882 | label: "clippy::map_identity", |
5340 | description: r##"Checks for instances of `map(f)` where `f` is the identity function."##, | 5883 | description: r##"Checks for instances of `map(f)` where `f` is the identity function."##, |
5341 | }, | 5884 | }, |
5342 | LintCompletion { | 5885 | Lint { |
5343 | label: "clippy::map_unwrap_or", | 5886 | label: "clippy::map_unwrap_or", |
5344 | description: r##"Checks for usage of `option.map(_).unwrap_or(_)` or `option.map(_).unwrap_or_else(_)` or\n`result.map(_).unwrap_or_else(_)`."##, | 5887 | description: r##"Checks for usage of `option.map(_).unwrap_or(_)` or `option.map(_).unwrap_or_else(_)` or\n`result.map(_).unwrap_or_else(_)`."##, |
5345 | }, | 5888 | }, |
5346 | LintCompletion { | 5889 | Lint { |
5347 | label: "clippy::match_as_ref", | 5890 | label: "clippy::match_as_ref", |
5348 | description: r##"Checks for match which is used to add a reference to an\n`Option` value."##, | 5891 | description: r##"Checks for match which is used to add a reference to an\n`Option` value."##, |
5349 | }, | 5892 | }, |
5350 | LintCompletion { | 5893 | Lint { |
5351 | label: "clippy::match_bool", | 5894 | label: "clippy::match_bool", |
5352 | description: r##"Checks for matches where match expression is a `bool`. It\nsuggests to replace the expression with an `if...else` block."##, | 5895 | description: r##"Checks for matches where match expression is a `bool`. It\nsuggests to replace the expression with an `if...else` block."##, |
5353 | }, | 5896 | }, |
5354 | LintCompletion { | 5897 | Lint { |
5355 | label: "clippy::match_like_matches_macro", | 5898 | label: "clippy::match_like_matches_macro", |
5356 | description: r##"Checks for `match` or `if let` expressions producing a\n`bool` that could be written using `matches!`"##, | 5899 | description: r##"Checks for `match` or `if let` expressions producing a\n`bool` that could be written using `matches!`"##, |
5357 | }, | 5900 | }, |
5358 | LintCompletion { | 5901 | Lint { |
5359 | label: "clippy::match_on_vec_items", | 5902 | label: "clippy::match_on_vec_items", |
5360 | description: r##"Checks for `match vec[idx]` or `match vec[n..m]`."##, | 5903 | description: r##"Checks for `match vec[idx]` or `match vec[n..m]`."##, |
5361 | }, | 5904 | }, |
5362 | LintCompletion { | 5905 | Lint { |
5363 | label: "clippy::match_overlapping_arm", | 5906 | label: "clippy::match_overlapping_arm", |
5364 | description: r##"Checks for overlapping match arms."##, | 5907 | description: r##"Checks for overlapping match arms."##, |
5365 | }, | 5908 | }, |
5366 | LintCompletion { | 5909 | Lint { |
5367 | label: "clippy::match_ref_pats", | 5910 | label: "clippy::match_ref_pats", |
5368 | description: r##"Checks for matches where all arms match a reference,\nsuggesting to remove the reference and deref the matched expression\ninstead. It also checks for `if let &foo = bar` blocks."##, | 5911 | description: r##"Checks for matches where all arms match a reference,\nsuggesting to remove the reference and deref the matched expression\ninstead. It also checks for `if let &foo = bar` blocks."##, |
5369 | }, | 5912 | }, |
5370 | LintCompletion { | 5913 | Lint { |
5371 | label: "clippy::match_same_arms", | 5914 | label: "clippy::match_same_arms", |
5372 | description: r##"Checks for `match` with identical arm bodies."##, | 5915 | description: r##"Checks for `match` with identical arm bodies."##, |
5373 | }, | 5916 | }, |
5374 | LintCompletion { | 5917 | Lint { |
5375 | label: "clippy::match_single_binding", | 5918 | label: "clippy::match_single_binding", |
5376 | description: r##"Checks for useless match that binds to only one value."##, | 5919 | description: r##"Checks for useless match that binds to only one value."##, |
5377 | }, | 5920 | }, |
5378 | LintCompletion { | 5921 | Lint { |
5379 | label: "clippy::match_wild_err_arm", | 5922 | label: "clippy::match_wild_err_arm", |
5380 | description: r##"Checks for arm which matches all errors with `Err(_)`\nand take drastic actions like `panic!`."##, | 5923 | description: r##"Checks for arm which matches all errors with `Err(_)`\nand take drastic actions like `panic!`."##, |
5381 | }, | 5924 | }, |
5382 | LintCompletion { | 5925 | Lint { |
5383 | label: "clippy::match_wildcard_for_single_variants", | 5926 | label: "clippy::match_wildcard_for_single_variants", |
5384 | description: r##"Checks for wildcard enum matches for a single variant."##, | 5927 | description: r##"Checks for wildcard enum matches for a single variant."##, |
5385 | }, | 5928 | }, |
5386 | LintCompletion { | 5929 | Lint { |
5387 | label: "clippy::maybe_infinite_iter", | 5930 | label: "clippy::maybe_infinite_iter", |
5388 | description: r##"Checks for iteration that may be infinite."##, | 5931 | description: r##"Checks for iteration that may be infinite."##, |
5389 | }, | 5932 | }, |
5390 | LintCompletion { | 5933 | Lint { |
5391 | label: "clippy::mem_discriminant_non_enum", | 5934 | label: "clippy::mem_discriminant_non_enum", |
5392 | description: r##"Checks for calls of `mem::discriminant()` on a non-enum type."##, | 5935 | description: r##"Checks for calls of `mem::discriminant()` on a non-enum type."##, |
5393 | }, | 5936 | }, |
5394 | LintCompletion { | 5937 | Lint { |
5395 | label: "clippy::mem_forget", | 5938 | label: "clippy::mem_forget", |
5396 | description: r##"Checks for usage of `std::mem::forget(t)` where `t` is\n`Drop`."##, | 5939 | description: r##"Checks for usage of `std::mem::forget(t)` where `t` is\n`Drop`."##, |
5397 | }, | 5940 | }, |
5398 | LintCompletion { | 5941 | Lint { |
5399 | label: "clippy::mem_replace_option_with_none", | 5942 | label: "clippy::mem_replace_option_with_none", |
5400 | description: r##"Checks for `mem::replace()` on an `Option` with\n`None`."##, | 5943 | description: r##"Checks for `mem::replace()` on an `Option` with\n`None`."##, |
5401 | }, | 5944 | }, |
5402 | LintCompletion { | 5945 | Lint { |
5403 | label: "clippy::mem_replace_with_default", | 5946 | label: "clippy::mem_replace_with_default", |
5404 | description: r##"Checks for `std::mem::replace` on a value of type\n`T` with `T::default()`."##, | 5947 | description: r##"Checks for `std::mem::replace` on a value of type\n`T` with `T::default()`."##, |
5405 | }, | 5948 | }, |
5406 | LintCompletion { | 5949 | Lint { |
5407 | label: "clippy::mem_replace_with_uninit", | 5950 | label: "clippy::mem_replace_with_uninit", |
5408 | description: r##"Checks for `mem::replace(&mut _, mem::uninitialized())`\nand `mem::replace(&mut _, mem::zeroed())`."##, | 5951 | description: r##"Checks for `mem::replace(&mut _, mem::uninitialized())`\nand `mem::replace(&mut _, mem::zeroed())`."##, |
5409 | }, | 5952 | }, |
5410 | LintCompletion { | 5953 | Lint { |
5411 | label: "clippy::min_max", | 5954 | label: "clippy::min_max", |
5412 | description: r##"Checks for expressions where `std::cmp::min` and `max` are\nused to clamp values, but switched so that the result is constant."##, | 5955 | description: r##"Checks for expressions where `std::cmp::min` and `max` are\nused to clamp values, but switched so that the result is constant."##, |
5413 | }, | 5956 | }, |
5414 | LintCompletion { | 5957 | Lint { |
5415 | label: "clippy::misaligned_transmute", | 5958 | label: "clippy::misaligned_transmute", |
5416 | description: r##"Nothing. This lint has been deprecated."##, | 5959 | description: r##"Nothing. This lint has been deprecated."##, |
5417 | }, | 5960 | }, |
5418 | LintCompletion { | 5961 | Lint { |
5419 | label: "clippy::mismatched_target_os", | 5962 | label: "clippy::mismatched_target_os", |
5420 | description: r##"Checks for cfg attributes having operating systems used in target family position."##, | 5963 | description: r##"Checks for cfg attributes having operating systems used in target family position."##, |
5421 | }, | 5964 | }, |
5422 | LintCompletion { | 5965 | Lint { |
5423 | label: "clippy::misrefactored_assign_op", | 5966 | label: "clippy::misrefactored_assign_op", |
5424 | description: r##"Checks for `a op= a op b` or `a op= b op a` patterns."##, | 5967 | description: r##"Checks for `a op= a op b` or `a op= b op a` patterns."##, |
5425 | }, | 5968 | }, |
5426 | LintCompletion { | 5969 | Lint { |
5427 | label: "clippy::missing_const_for_fn", | 5970 | label: "clippy::missing_const_for_fn", |
5428 | description: r##"Suggests the use of `const` in functions and methods where possible."##, | 5971 | description: r##"Suggests the use of `const` in functions and methods where possible."##, |
5429 | }, | 5972 | }, |
5430 | LintCompletion { | 5973 | Lint { |
5431 | label: "clippy::missing_docs_in_private_items", | 5974 | label: "clippy::missing_docs_in_private_items", |
5432 | description: r##"Warns if there is missing doc for any documentable item\n(public or private)."##, | 5975 | description: r##"Warns if there is missing doc for any documentable item\n(public or private)."##, |
5433 | }, | 5976 | }, |
5434 | LintCompletion { | 5977 | Lint { |
5435 | label: "clippy::missing_errors_doc", | 5978 | label: "clippy::missing_errors_doc", |
5436 | description: r##"Checks the doc comments of publicly visible functions that\nreturn a `Result` type and warns if there is no `# Errors` section."##, | 5979 | description: r##"Checks the doc comments of publicly visible functions that\nreturn a `Result` type and warns if there is no `# Errors` section."##, |
5437 | }, | 5980 | }, |
5438 | LintCompletion { | 5981 | Lint { |
5439 | label: "clippy::missing_inline_in_public_items", | 5982 | label: "clippy::missing_inline_in_public_items", |
5440 | description: r##"it lints if an exported function, method, trait method with default impl,\nor trait method impl is not `#[inline]`."##, | 5983 | description: r##"it lints if an exported function, method, trait method with default impl,\nor trait method impl is not `#[inline]`."##, |
5441 | }, | 5984 | }, |
5442 | LintCompletion { | 5985 | Lint { |
5443 | label: "clippy::missing_panics_doc", | 5986 | label: "clippy::missing_panics_doc", |
5444 | description: r##"Checks the doc comments of publicly visible functions that\nmay panic and warns if there is no `# Panics` section."##, | 5987 | description: r##"Checks the doc comments of publicly visible functions that\nmay panic and warns if there is no `# Panics` section."##, |
5445 | }, | 5988 | }, |
5446 | LintCompletion { | 5989 | Lint { |
5447 | label: "clippy::missing_safety_doc", | 5990 | label: "clippy::missing_safety_doc", |
5448 | description: r##"Checks for the doc comments of publicly visible\nunsafe functions and warns if there is no `# Safety` section."##, | 5991 | description: r##"Checks for the doc comments of publicly visible\nunsafe functions and warns if there is no `# Safety` section."##, |
5449 | }, | 5992 | }, |
5450 | LintCompletion { | 5993 | Lint { |
5451 | label: "clippy::mistyped_literal_suffixes", | 5994 | label: "clippy::mistyped_literal_suffixes", |
5452 | description: r##"Warns for mistyped suffix in literals"##, | 5995 | description: r##"Warns for mistyped suffix in literals"##, |
5453 | }, | 5996 | }, |
5454 | LintCompletion { | 5997 | Lint { |
5455 | label: "clippy::mixed_case_hex_literals", | 5998 | label: "clippy::mixed_case_hex_literals", |
5456 | description: r##"Warns on hexadecimal literals with mixed-case letter\ndigits."##, | 5999 | description: r##"Warns on hexadecimal literals with mixed-case letter\ndigits."##, |
5457 | }, | 6000 | }, |
5458 | LintCompletion { | 6001 | Lint { |
5459 | label: "clippy::module_inception", | 6002 | label: "clippy::module_inception", |
5460 | description: r##"Checks for modules that have the same name as their\nparent module"##, | 6003 | description: r##"Checks for modules that have the same name as their\nparent module"##, |
5461 | }, | 6004 | }, |
5462 | LintCompletion { | 6005 | Lint { |
5463 | label: "clippy::module_name_repetitions", | 6006 | label: "clippy::module_name_repetitions", |
5464 | description: r##"Detects type names that are prefixed or suffixed by the\ncontaining module's name."##, | 6007 | description: r##"Detects type names that are prefixed or suffixed by the\ncontaining module's name."##, |
5465 | }, | 6008 | }, |
5466 | LintCompletion { | 6009 | Lint { label: "clippy::modulo_arithmetic", description: r##"Checks for modulo arithmetic."## }, |
5467 | label: "clippy::modulo_arithmetic", | 6010 | Lint { |
5468 | description: r##"Checks for modulo arithmetic."##, | ||
5469 | }, | ||
5470 | LintCompletion { | ||
5471 | label: "clippy::modulo_one", | 6011 | label: "clippy::modulo_one", |
5472 | description: r##"Checks for getting the remainder of a division by one or minus\none."##, | 6012 | description: r##"Checks for getting the remainder of a division by one or minus\none."##, |
5473 | }, | 6013 | }, |
5474 | LintCompletion { | 6014 | Lint { |
5475 | label: "clippy::multiple_crate_versions", | 6015 | label: "clippy::multiple_crate_versions", |
5476 | description: r##"Checks to see if multiple versions of a crate are being\nused."##, | 6016 | description: r##"Checks to see if multiple versions of a crate are being\nused."##, |
5477 | }, | 6017 | }, |
5478 | LintCompletion { | 6018 | Lint { |
5479 | label: "clippy::multiple_inherent_impl", | 6019 | label: "clippy::multiple_inherent_impl", |
5480 | description: r##"Checks for multiple inherent implementations of a struct"##, | 6020 | description: r##"Checks for multiple inherent implementations of a struct"##, |
5481 | }, | 6021 | }, |
5482 | LintCompletion { | 6022 | Lint { |
5483 | label: "clippy::must_use_candidate", | 6023 | label: "clippy::must_use_candidate", |
5484 | description: r##"Checks for public functions that have no\n[`#[must_use]`] attribute, but return something not already marked\nmust-use, have no mutable arg and mutate no statics.\n\n[`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"##, | 6024 | description: r##"Checks for public functions that have no\n[`#[must_use]`] attribute, but return something not already marked\nmust-use, have no mutable arg and mutate no statics.\n\n[`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"##, |
5485 | }, | 6025 | }, |
5486 | LintCompletion { | 6026 | Lint { |
5487 | label: "clippy::must_use_unit", | 6027 | label: "clippy::must_use_unit", |
5488 | description: r##"Checks for a [`#[must_use]`] attribute on\nunit-returning functions and methods.\n\n[`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"##, | 6028 | description: r##"Checks for a [`#[must_use]`] attribute on\nunit-returning functions and methods.\n\n[`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute"##, |
5489 | }, | 6029 | }, |
5490 | LintCompletion { | 6030 | Lint { |
5491 | label: "clippy::mut_from_ref", | 6031 | label: "clippy::mut_from_ref", |
5492 | description: r##"This lint checks for functions that take immutable\nreferences and return mutable ones."##, | 6032 | description: r##"This lint checks for functions that take immutable\nreferences and return mutable ones."##, |
5493 | }, | 6033 | }, |
5494 | LintCompletion { | 6034 | Lint { |
5495 | label: "clippy::mut_mut", | 6035 | label: "clippy::mut_mut", |
5496 | description: r##"Checks for instances of `mut mut` references."##, | 6036 | description: r##"Checks for instances of `mut mut` references."##, |
5497 | }, | 6037 | }, |
5498 | LintCompletion { | 6038 | Lint { |
5499 | label: "clippy::mut_mutex_lock", | 6039 | label: "clippy::mut_mutex_lock", |
5500 | description: r##"Checks for `&mut Mutex::lock` calls"##, | 6040 | description: r##"Checks for `&mut Mutex::lock` calls"##, |
5501 | }, | 6041 | }, |
5502 | LintCompletion { | 6042 | Lint { |
5503 | label: "clippy::mut_range_bound", | 6043 | label: "clippy::mut_range_bound", |
5504 | description: r##"Checks for loops which have a range bound that is a mutable variable"##, | 6044 | description: r##"Checks for loops which have a range bound that is a mutable variable"##, |
5505 | }, | 6045 | }, |
5506 | LintCompletion { | 6046 | Lint { |
5507 | label: "clippy::mutable_key_type", | 6047 | label: "clippy::mutable_key_type", |
5508 | description: r##"Checks for sets/maps with mutable key types."##, | 6048 | description: r##"Checks for sets/maps with mutable key types."##, |
5509 | }, | 6049 | }, |
5510 | LintCompletion { | 6050 | Lint { |
5511 | label: "clippy::mutex_atomic", | 6051 | label: "clippy::mutex_atomic", |
5512 | description: r##"Checks for usages of `Mutex<X>` where an atomic will do."##, | 6052 | description: r##"Checks for usages of `Mutex<X>` where an atomic will do."##, |
5513 | }, | 6053 | }, |
5514 | LintCompletion { | 6054 | Lint { |
5515 | label: "clippy::mutex_integer", | 6055 | label: "clippy::mutex_integer", |
5516 | description: r##"Checks for usages of `Mutex<X>` where `X` is an integral\ntype."##, | 6056 | description: r##"Checks for usages of `Mutex<X>` where `X` is an integral\ntype."##, |
5517 | }, | 6057 | }, |
5518 | LintCompletion { | 6058 | Lint { label: "clippy::naive_bytecount", description: r##"Checks for naive byte counts"## }, |
5519 | label: "clippy::naive_bytecount", | 6059 | Lint { |
5520 | description: r##"Checks for naive byte counts"##, | ||
5521 | }, | ||
5522 | LintCompletion { | ||
5523 | label: "clippy::needless_arbitrary_self_type", | 6060 | label: "clippy::needless_arbitrary_self_type", |
5524 | description: r##"The lint checks for `self` in fn parameters that\nspecify the `Self`-type explicitly"##, | 6061 | description: r##"The lint checks for `self` in fn parameters that\nspecify the `Self`-type explicitly"##, |
5525 | }, | 6062 | }, |
5526 | LintCompletion { | 6063 | Lint { |
6064 | label: "clippy::needless_bitwise_bool", | ||
6065 | description: r##"Checks for uses of bitwise and/or operators between booleans, where performance may be improved by using\na lazy and."##, | ||
6066 | }, | ||
6067 | Lint { | ||
5527 | label: "clippy::needless_bool", | 6068 | label: "clippy::needless_bool", |
5528 | description: r##"Checks for expressions of the form `if c { true } else {\nfalse }` (or vice versa) and suggests using the condition directly."##, | 6069 | description: r##"Checks for expressions of the form `if c { true } else {\nfalse }` (or vice versa) and suggests using the condition directly."##, |
5529 | }, | 6070 | }, |
5530 | LintCompletion { | 6071 | Lint { |
5531 | label: "clippy::needless_borrow", | 6072 | label: "clippy::needless_borrow", |
5532 | description: r##"Checks for address of operations (`&`) that are going to\nbe dereferenced immediately by the compiler."##, | 6073 | description: r##"Checks for address of operations (`&`) that are going to\nbe dereferenced immediately by the compiler."##, |
5533 | }, | 6074 | }, |
5534 | LintCompletion { | 6075 | Lint { |
5535 | label: "clippy::needless_borrowed_reference", | 6076 | label: "clippy::needless_borrowed_reference", |
5536 | description: r##"Checks for useless borrowed references."##, | 6077 | description: r##"Checks for bindings that destructure a reference and borrow the inner\nvalue with `&ref`."##, |
5537 | }, | 6078 | }, |
5538 | LintCompletion { | 6079 | Lint { |
5539 | label: "clippy::needless_collect", | 6080 | label: "clippy::needless_collect", |
5540 | description: r##"Checks for functions collecting an iterator when collect\nis not needed."##, | 6081 | description: r##"Checks for functions collecting an iterator when collect\nis not needed."##, |
5541 | }, | 6082 | }, |
5542 | LintCompletion { | 6083 | Lint { |
5543 | label: "clippy::needless_continue", | 6084 | label: "clippy::needless_continue", |
5544 | description: r##"The lint checks for `if`-statements appearing in loops\nthat contain a `continue` statement in either their main blocks or their\n`else`-blocks, when omitting the `else`-block possibly with some\nrearrangement of code can make the code easier to understand."##, | 6085 | description: r##"The lint checks for `if`-statements appearing in loops\nthat contain a `continue` statement in either their main blocks or their\n`else`-blocks, when omitting the `else`-block possibly with some\nrearrangement of code can make the code easier to understand."##, |
5545 | }, | 6086 | }, |
5546 | LintCompletion { | 6087 | Lint { |
5547 | label: "clippy::needless_doctest_main", | 6088 | label: "clippy::needless_doctest_main", |
5548 | description: r##"Checks for `fn main() { .. }` in doctests"##, | 6089 | description: r##"Checks for `fn main() { .. }` in doctests"##, |
5549 | }, | 6090 | }, |
5550 | LintCompletion { | 6091 | Lint { |
6092 | label: "clippy::needless_for_each", | ||
6093 | description: r##"Checks for usage of `for_each` that would be more simply written as a\n`for` loop."##, | ||
6094 | }, | ||
6095 | Lint { | ||
5551 | label: "clippy::needless_lifetimes", | 6096 | label: "clippy::needless_lifetimes", |
5552 | description: r##"Checks for lifetime annotations which can be removed by\nrelying on lifetime elision."##, | 6097 | description: r##"Checks for lifetime annotations which can be removed by\nrelying on lifetime elision."##, |
5553 | }, | 6098 | }, |
5554 | LintCompletion { | 6099 | Lint { |
5555 | label: "clippy::needless_pass_by_value", | 6100 | label: "clippy::needless_pass_by_value", |
5556 | description: r##"Checks for functions taking arguments by value, but not\nconsuming them in its\nbody."##, | 6101 | description: r##"Checks for functions taking arguments by value, but not\nconsuming them in its\nbody."##, |
5557 | }, | 6102 | }, |
5558 | LintCompletion { | 6103 | Lint { |
5559 | label: "clippy::needless_question_mark", | 6104 | label: "clippy::needless_question_mark", |
5560 | description: r##"Suggests alternatives for useless applications of `?` in terminating expressions"##, | 6105 | description: r##"Suggests alternatives for useless applications of `?` in terminating expressions"##, |
5561 | }, | 6106 | }, |
5562 | LintCompletion { | 6107 | Lint { |
5563 | label: "clippy::needless_range_loop", | 6108 | label: "clippy::needless_range_loop", |
5564 | description: r##"Checks for looping over the range of `0..len` of some\ncollection just to get the values by index."##, | 6109 | description: r##"Checks for looping over the range of `0..len` of some\ncollection just to get the values by index."##, |
5565 | }, | 6110 | }, |
5566 | LintCompletion { | 6111 | Lint { |
5567 | label: "clippy::needless_return", | 6112 | label: "clippy::needless_return", |
5568 | description: r##"Checks for return statements at the end of a block."##, | 6113 | description: r##"Checks for return statements at the end of a block."##, |
5569 | }, | 6114 | }, |
5570 | LintCompletion { | 6115 | Lint { |
5571 | label: "clippy::needless_update", | 6116 | label: "clippy::needless_update", |
5572 | description: r##"Checks for needlessly including a base struct on update\nwhen all fields are changed anyway.\n\nThis lint is not applied to structs marked with\n[non_exhaustive](https://doc.rust-lang.org/reference/attributes/type_system.html)."##, | 6117 | description: r##"Checks for needlessly including a base struct on update\nwhen all fields are changed anyway.\n\nThis lint is not applied to structs marked with\n[non_exhaustive](https://doc.rust-lang.org/reference/attributes/type_system.html)."##, |
5573 | }, | 6118 | }, |
5574 | LintCompletion { | 6119 | Lint { |
5575 | label: "clippy::neg_cmp_op_on_partial_ord", | 6120 | label: "clippy::neg_cmp_op_on_partial_ord", |
5576 | description: r##"Checks for the usage of negated comparison operators on types which only implement\n`PartialOrd` (e.g., `f64`)."##, | 6121 | description: r##"Checks for the usage of negated comparison operators on types which only implement\n`PartialOrd` (e.g., `f64`)."##, |
5577 | }, | 6122 | }, |
5578 | LintCompletion { | 6123 | Lint { |
5579 | label: "clippy::neg_multiply", | 6124 | label: "clippy::neg_multiply", |
5580 | description: r##"Checks for multiplication by -1 as a form of negation."##, | 6125 | description: r##"Checks for multiplication by -1 as a form of negation."##, |
5581 | }, | 6126 | }, |
5582 | LintCompletion { | 6127 | Lint { |
5583 | label: "clippy::never_loop", | 6128 | label: "clippy::never_loop", |
5584 | description: r##"Checks for loops that will always `break`, `return` or\n`continue` an outer loop."##, | 6129 | description: r##"Checks for loops that will always `break`, `return` or\n`continue` an outer loop."##, |
5585 | }, | 6130 | }, |
5586 | LintCompletion { | 6131 | Lint { |
5587 | label: "clippy::new_ret_no_self", | 6132 | label: "clippy::new_ret_no_self", |
5588 | description: r##"Checks for `new` not returning a type that contains `Self`."##, | 6133 | description: r##"Checks for `new` not returning a type that contains `Self`."##, |
5589 | }, | 6134 | }, |
5590 | LintCompletion { | 6135 | Lint { |
5591 | label: "clippy::new_without_default", | 6136 | label: "clippy::new_without_default", |
5592 | description: r##"Checks for types with a `fn new() -> Self` method and no\nimplementation of\n[`Default`](https://doc.rust-lang.org/std/default/trait.Default.html)."##, | 6137 | description: r##"Checks for types with a `fn new() -> Self` method and no\nimplementation of\n[`Default`](https://doc.rust-lang.org/std/default/trait.Default.html)."##, |
5593 | }, | 6138 | }, |
5594 | LintCompletion { | 6139 | Lint { |
5595 | label: "clippy::no_effect", | 6140 | label: "clippy::no_effect", |
5596 | description: r##"Checks for statements which have no effect."##, | 6141 | description: r##"Checks for statements which have no effect."##, |
5597 | }, | 6142 | }, |
5598 | LintCompletion { | 6143 | Lint { |
5599 | label: "clippy::non_ascii_literal", | 6144 | label: "clippy::non_ascii_literal", |
5600 | description: r##"Checks for non-ASCII characters in string literals."##, | 6145 | description: r##"Checks for non-ASCII characters in string literals."##, |
5601 | }, | 6146 | }, |
5602 | LintCompletion { | 6147 | Lint { |
6148 | label: "clippy::non_octal_unix_permissions", | ||
6149 | description: r##"Checks for non-octal values used to set Unix file permissions."##, | ||
6150 | }, | ||
6151 | Lint { | ||
5603 | label: "clippy::nonminimal_bool", | 6152 | label: "clippy::nonminimal_bool", |
5604 | description: r##"Checks for boolean expressions that can be written more\nconcisely."##, | 6153 | description: r##"Checks for boolean expressions that can be written more\nconcisely."##, |
5605 | }, | 6154 | }, |
5606 | LintCompletion { | 6155 | Lint { |
5607 | label: "clippy::nonsensical_open_options", | 6156 | label: "clippy::nonsensical_open_options", |
5608 | description: r##"Checks for duplicate open options as well as combinations\nthat make no sense."##, | 6157 | description: r##"Checks for duplicate open options as well as combinations\nthat make no sense."##, |
5609 | }, | 6158 | }, |
5610 | LintCompletion { | 6159 | Lint { |
5611 | label: "clippy::not_unsafe_ptr_arg_deref", | 6160 | label: "clippy::not_unsafe_ptr_arg_deref", |
5612 | description: r##"Checks for public functions that dereference raw pointer\narguments but are not marked unsafe."##, | 6161 | description: r##"Checks for public functions that dereference raw pointer\narguments but are not marked `unsafe`."##, |
5613 | }, | 6162 | }, |
5614 | LintCompletion { | 6163 | Lint { label: "clippy::ok_expect", description: r##"Checks for usage of `ok().expect(..)`."## }, |
5615 | label: "clippy::ok_expect", | 6164 | Lint { |
5616 | description: r##"Checks for usage of `ok().expect(..)`."##, | ||
5617 | }, | ||
5618 | LintCompletion { | ||
5619 | label: "clippy::op_ref", | 6165 | label: "clippy::op_ref", |
5620 | description: r##"Checks for arguments to `==` which have their address\ntaken to satisfy a bound\nand suggests to dereference the other argument instead"##, | 6166 | description: r##"Checks for arguments to `==` which have their address\ntaken to satisfy a bound\nand suggests to dereference the other argument instead"##, |
5621 | }, | 6167 | }, |
5622 | LintCompletion { | 6168 | Lint { |
5623 | label: "clippy::option_as_ref_deref", | 6169 | label: "clippy::option_as_ref_deref", |
5624 | description: r##"Checks for usage of `_.as_ref().map(Deref::deref)` or it's aliases (such as String::as_str)."##, | 6170 | description: r##"Checks for usage of `_.as_ref().map(Deref::deref)` or it's aliases (such as String::as_str)."##, |
5625 | }, | 6171 | }, |
5626 | LintCompletion { | 6172 | Lint { |
5627 | label: "clippy::option_env_unwrap", | 6173 | label: "clippy::option_env_unwrap", |
5628 | description: r##"Checks for usage of `option_env!(...).unwrap()` and\nsuggests usage of the `env!` macro."##, | 6174 | description: r##"Checks for usage of `option_env!(...).unwrap()` and\nsuggests usage of the `env!` macro."##, |
5629 | }, | 6175 | }, |
5630 | LintCompletion { | 6176 | Lint { |
6177 | label: "clippy::option_filter_map", | ||
6178 | description: r##"Checks for indirect collection of populated `Option`"##, | ||
6179 | }, | ||
6180 | Lint { | ||
5631 | label: "clippy::option_if_let_else", | 6181 | label: "clippy::option_if_let_else", |
5632 | description: r##"Lints usage of `if let Some(v) = ... { y } else { x }` which is more\nidiomatically done with `Option::map_or` (if the else bit is a pure\nexpression) or `Option::map_or_else` (if the else bit is an impure\nexpression)."##, | 6182 | description: r##"Lints usage of `if let Some(v) = ... { y } else { x }` which is more\nidiomatically done with `Option::map_or` (if the else bit is a pure\nexpression) or `Option::map_or_else` (if the else bit is an impure\nexpression)."##, |
5633 | }, | 6183 | }, |
5634 | LintCompletion { | 6184 | Lint { |
5635 | label: "clippy::option_map_or_none", | 6185 | label: "clippy::option_map_or_none", |
5636 | description: r##"Checks for usage of `_.map_or(None, _)`."##, | 6186 | description: r##"Checks for usage of `_.map_or(None, _)`."##, |
5637 | }, | 6187 | }, |
5638 | LintCompletion { | 6188 | Lint { |
5639 | label: "clippy::option_map_unit_fn", | 6189 | label: "clippy::option_map_unit_fn", |
5640 | description: r##"Checks for usage of `option.map(f)` where f is a function\nor closure that returns the unit type `()`."##, | 6190 | description: r##"Checks for usage of `option.map(f)` where f is a function\nor closure that returns the unit type `()`."##, |
5641 | }, | 6191 | }, |
5642 | LintCompletion { | 6192 | Lint { |
5643 | label: "clippy::option_option", | 6193 | label: "clippy::option_option", |
5644 | description: r##"Checks for use of `Option<Option<_>>` in function signatures and type\ndefinitions"##, | 6194 | description: r##"Checks for use of `Option<Option<_>>` in function signatures and type\ndefinitions"##, |
5645 | }, | 6195 | }, |
5646 | LintCompletion { | 6196 | Lint { |
5647 | label: "clippy::or_fun_call", | 6197 | label: "clippy::or_fun_call", |
5648 | description: r##"Checks for calls to `.or(foo(..))`, `.unwrap_or(foo(..))`,\netc., and suggests to use `or_else`, `unwrap_or_else`, etc., or\n`unwrap_or_default` instead."##, | 6198 | description: r##"Checks for calls to `.or(foo(..))`, `.unwrap_or(foo(..))`,\netc., and suggests to use `or_else`, `unwrap_or_else`, etc., or\n`unwrap_or_default` instead."##, |
5649 | }, | 6199 | }, |
5650 | LintCompletion { | 6200 | Lint { |
5651 | label: "clippy::out_of_bounds_indexing", | 6201 | label: "clippy::out_of_bounds_indexing", |
5652 | description: r##"Checks for out of bounds array indexing with a constant\nindex."##, | 6202 | description: r##"Checks for out of bounds array indexing with a constant\nindex."##, |
5653 | }, | 6203 | }, |
5654 | LintCompletion { | 6204 | Lint { |
5655 | label: "clippy::overflow_check_conditional", | 6205 | label: "clippy::overflow_check_conditional", |
5656 | description: r##"Detects classic underflow/overflow checks."##, | 6206 | description: r##"Detects classic underflow/overflow checks."##, |
5657 | }, | 6207 | }, |
5658 | LintCompletion { label: "clippy::panic", description: r##"Checks for usage of `panic!`."## }, | 6208 | Lint { label: "clippy::panic", description: r##"Checks for usage of `panic!`."## }, |
5659 | LintCompletion { | 6209 | Lint { |
5660 | label: "clippy::panic_in_result_fn", | 6210 | label: "clippy::panic_in_result_fn", |
5661 | description: r##"Checks for usage of `panic!`, `unimplemented!`, `todo!`, `unreachable!` or assertions in a function of type result."##, | 6211 | description: r##"Checks for usage of `panic!`, `unimplemented!`, `todo!`, `unreachable!` or assertions in a function of type result."##, |
5662 | }, | 6212 | }, |
5663 | LintCompletion { | 6213 | Lint { |
5664 | label: "clippy::panic_params", | ||
5665 | description: r##"Nothing. This lint has been deprecated."##, | ||
5666 | }, | ||
5667 | LintCompletion { | ||
5668 | label: "clippy::panicking_unwrap", | 6214 | label: "clippy::panicking_unwrap", |
5669 | description: r##"Checks for calls of `unwrap[_err]()` that will always fail."##, | 6215 | description: r##"Checks for calls of `unwrap[_err]()` that will always fail."##, |
5670 | }, | 6216 | }, |
5671 | LintCompletion { | 6217 | Lint { |
5672 | label: "clippy::partialeq_ne_impl", | 6218 | label: "clippy::partialeq_ne_impl", |
5673 | description: r##"Checks for manual re-implementations of `PartialEq::ne`."##, | 6219 | description: r##"Checks for manual re-implementations of `PartialEq::ne`."##, |
5674 | }, | 6220 | }, |
5675 | LintCompletion { | 6221 | Lint { |
5676 | label: "clippy::path_buf_push_overwrite", | 6222 | label: "clippy::path_buf_push_overwrite", |
5677 | description: r##"* Checks for [push](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.push)\ncalls on `PathBuf` that can cause overwrites."##, | 6223 | description: r##"* Checks for [push](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.push)\ncalls on `PathBuf` that can cause overwrites."##, |
5678 | }, | 6224 | }, |
5679 | LintCompletion { | 6225 | Lint { |
5680 | label: "clippy::pattern_type_mismatch", | 6226 | label: "clippy::pattern_type_mismatch", |
5681 | description: r##"Checks for patterns that aren't exact representations of the types\nthey are applied to.\n\nTo satisfy this lint, you will have to adjust either the expression that is matched\nagainst or the pattern itself, as well as the bindings that are introduced by the\nadjusted patterns. For matching you will have to either dereference the expression\nwith the `*` operator, or amend the patterns to explicitly match against `&<pattern>`\nor `&mut <pattern>` depending on the reference mutability. For the bindings you need\nto use the inverse. You can leave them as plain bindings if you wish for the value\nto be copied, but you must use `ref mut <variable>` or `ref <variable>` to construct\na reference into the matched structure.\n\nIf you are looking for a way to learn about ownership semantics in more detail, it\nis recommended to look at IDE options available to you to highlight types, lifetimes\nand reference semantics in your code. The available tooling would expose these things\nin a general way even outside of the various pattern matching mechanics. Of course\nthis lint can still be used to highlight areas of interest and ensure a good understanding\nof ownership semantics."##, | 6227 | description: r##"Checks for patterns that aren't exact representations of the types\nthey are applied to.\n\nTo satisfy this lint, you will have to adjust either the expression that is matched\nagainst or the pattern itself, as well as the bindings that are introduced by the\nadjusted patterns. For matching you will have to either dereference the expression\nwith the `*` operator, or amend the patterns to explicitly match against `&<pattern>`\nor `&mut <pattern>` depending on the reference mutability. For the bindings you need\nto use the inverse. You can leave them as plain bindings if you wish for the value\nto be copied, but you must use `ref mut <variable>` or `ref <variable>` to construct\na reference into the matched structure.\n\nIf you are looking for a way to learn about ownership semantics in more detail, it\nis recommended to look at IDE options available to you to highlight types, lifetimes\nand reference semantics in your code. The available tooling would expose these things\nin a general way even outside of the various pattern matching mechanics. Of course\nthis lint can still be used to highlight areas of interest and ensure a good understanding\nof ownership semantics."##, |
5682 | }, | 6228 | }, |
5683 | LintCompletion { | 6229 | Lint { |
5684 | label: "clippy::possible_missing_comma", | 6230 | label: "clippy::possible_missing_comma", |
5685 | description: r##"Checks for possible missing comma in an array. It lints if\nan array element is a binary operator expression and it lies on two lines."##, | 6231 | description: r##"Checks for possible missing comma in an array. It lints if\nan array element is a binary operator expression and it lies on two lines."##, |
5686 | }, | 6232 | }, |
5687 | LintCompletion { | 6233 | Lint { |
5688 | label: "clippy::precedence", | 6234 | label: "clippy::precedence", |
5689 | description: r##"Checks for operations where precedence may be unclear\nand suggests to add parentheses. Currently it catches the following:\n* mixed usage of arithmetic and bit shifting/combining operators without\nparentheses\n* a \"negative\" numeric literal (which is really a unary `-` followed by a\nnumeric literal)\n followed by a method call"##, | 6235 | description: r##"Checks for operations where precedence may be unclear\nand suggests to add parentheses. Currently it catches the following:\n* mixed usage of arithmetic and bit shifting/combining operators without\nparentheses\n* a \"negative\" numeric literal (which is really a unary `-` followed by a\nnumeric literal)\n followed by a method call"##, |
5690 | }, | 6236 | }, |
5691 | LintCompletion { | 6237 | Lint { |
5692 | label: "clippy::print_literal", | 6238 | label: "clippy::print_literal", |
5693 | description: r##"This lint warns about the use of literals as `print!`/`println!` args."##, | 6239 | description: r##"This lint warns about the use of literals as `print!`/`println!` args."##, |
5694 | }, | 6240 | }, |
5695 | LintCompletion { | 6241 | Lint { |
5696 | label: "clippy::print_stderr", | 6242 | label: "clippy::print_stderr", |
5697 | description: r##"Checks for printing on *stderr*. The purpose of this lint\nis to catch debugging remnants."##, | 6243 | description: r##"Checks for printing on *stderr*. The purpose of this lint\nis to catch debugging remnants."##, |
5698 | }, | 6244 | }, |
5699 | LintCompletion { | 6245 | Lint { |
5700 | label: "clippy::print_stdout", | 6246 | label: "clippy::print_stdout", |
5701 | description: r##"Checks for printing on *stdout*. The purpose of this lint\nis to catch debugging remnants."##, | 6247 | description: r##"Checks for printing on *stdout*. The purpose of this lint\nis to catch debugging remnants."##, |
5702 | }, | 6248 | }, |
5703 | LintCompletion { | 6249 | Lint { |
5704 | label: "clippy::print_with_newline", | 6250 | label: "clippy::print_with_newline", |
5705 | description: r##"This lint warns when you use `print!()` with a format\nstring that ends in a newline."##, | 6251 | description: r##"This lint warns when you use `print!()` with a format\nstring that ends in a newline."##, |
5706 | }, | 6252 | }, |
5707 | LintCompletion { | 6253 | Lint { |
5708 | label: "clippy::println_empty_string", | 6254 | label: "clippy::println_empty_string", |
5709 | description: r##"This lint warns when you use `println!(\"\")` to\nprint a newline."##, | 6255 | description: r##"This lint warns when you use `println!(\"\")` to\nprint a newline."##, |
5710 | }, | 6256 | }, |
5711 | LintCompletion { | 6257 | Lint { |
5712 | label: "clippy::ptr_arg", | 6258 | label: "clippy::ptr_arg", |
5713 | description: r##"This lint checks for function arguments of type `&String`\nor `&Vec` unless the references are mutable. It will also suggest you\nreplace `.clone()` calls with the appropriate `.to_owned()`/`to_string()`\ncalls."##, | 6259 | description: r##"This lint checks for function arguments of type `&String`\nor `&Vec` unless the references are mutable. It will also suggest you\nreplace `.clone()` calls with the appropriate `.to_owned()`/`to_string()`\ncalls."##, |
5714 | }, | 6260 | }, |
5715 | LintCompletion { | 6261 | Lint { |
5716 | label: "clippy::ptr_as_ptr", | 6262 | label: "clippy::ptr_as_ptr", |
5717 | description: r##"Checks for `as` casts between raw pointers without changing its mutability,\nnamely `*const T` to `*const U` and `*mut T` to `*mut U`."##, | 6263 | description: r##"Checks for `as` casts between raw pointers without changing its mutability,\nnamely `*const T` to `*const U` and `*mut T` to `*mut U`."##, |
5718 | }, | 6264 | }, |
5719 | LintCompletion { | 6265 | Lint { label: "clippy::ptr_eq", description: r##"Use `std::ptr::eq` when applicable"## }, |
5720 | label: "clippy::ptr_eq", | 6266 | Lint { |
5721 | description: r##"Use `std::ptr::eq` when applicable"##, | ||
5722 | }, | ||
5723 | LintCompletion { | ||
5724 | label: "clippy::ptr_offset_with_cast", | 6267 | label: "clippy::ptr_offset_with_cast", |
5725 | description: r##"Checks for usage of the `offset` pointer method with a `usize` casted to an\n`isize`."##, | 6268 | description: r##"Checks for usage of the `offset` pointer method with a `usize` casted to an\n`isize`."##, |
5726 | }, | 6269 | }, |
5727 | LintCompletion { | 6270 | Lint { |
5728 | label: "clippy::pub_enum_variant_names", | 6271 | label: "clippy::pub_enum_variant_names", |
5729 | description: r##"Detects public enumeration variants that are\nprefixed or suffixed by the same characters."##, | 6272 | description: r##"Nothing. This lint has been deprecated."##, |
5730 | }, | 6273 | }, |
5731 | LintCompletion { | 6274 | Lint { |
5732 | label: "clippy::question_mark", | 6275 | label: "clippy::question_mark", |
5733 | description: r##"Checks for expressions that could be replaced by the question mark operator."##, | 6276 | description: r##"Checks for expressions that could be replaced by the question mark operator."##, |
5734 | }, | 6277 | }, |
5735 | LintCompletion { | 6278 | Lint { |
5736 | label: "clippy::range_minus_one", | 6279 | label: "clippy::range_minus_one", |
5737 | description: r##"Checks for inclusive ranges where 1 is subtracted from\nthe upper bound, e.g., `x..=(y-1)`."##, | 6280 | description: r##"Checks for inclusive ranges where 1 is subtracted from\nthe upper bound, e.g., `x..=(y-1)`."##, |
5738 | }, | 6281 | }, |
5739 | LintCompletion { | 6282 | Lint { |
5740 | label: "clippy::range_plus_one", | 6283 | label: "clippy::range_plus_one", |
5741 | description: r##"Checks for exclusive ranges where 1 is added to the\nupper bound, e.g., `x..(y+1)`."##, | 6284 | description: r##"Checks for exclusive ranges where 1 is added to the\nupper bound, e.g., `x..(y+1)`."##, |
5742 | }, | 6285 | }, |
5743 | LintCompletion { | 6286 | Lint { |
5744 | label: "clippy::range_step_by_zero", | 6287 | label: "clippy::range_step_by_zero", |
5745 | description: r##"Nothing. This lint has been deprecated."##, | 6288 | description: r##"Nothing. This lint has been deprecated."##, |
5746 | }, | 6289 | }, |
5747 | LintCompletion { | 6290 | Lint { |
5748 | label: "clippy::range_zip_with_len", | 6291 | label: "clippy::range_zip_with_len", |
5749 | description: r##"Checks for zipping a collection with the range of\n`0.._.len()`."##, | 6292 | description: r##"Checks for zipping a collection with the range of\n`0.._.len()`."##, |
5750 | }, | 6293 | }, |
5751 | LintCompletion { | 6294 | Lint { |
5752 | label: "clippy::rc_buffer", | 6295 | label: "clippy::rc_buffer", |
5753 | description: r##"Checks for `Rc<T>` and `Arc<T>` when `T` is a mutable buffer type such as `String` or `Vec`."##, | 6296 | description: r##"Checks for `Rc<T>` and `Arc<T>` when `T` is a mutable buffer type such as `String` or `Vec`."##, |
5754 | }, | 6297 | }, |
5755 | LintCompletion { | 6298 | Lint { |
5756 | label: "clippy::redundant_allocation", | 6299 | label: "clippy::redundant_allocation", |
5757 | description: r##"Checks for use of redundant allocations anywhere in the code."##, | 6300 | description: r##"Checks for use of redundant allocations anywhere in the code."##, |
5758 | }, | 6301 | }, |
5759 | LintCompletion { | 6302 | Lint { |
5760 | label: "clippy::redundant_clone", | 6303 | label: "clippy::redundant_clone", |
5761 | description: r##"Checks for a redundant `clone()` (and its relatives) which clones an owned\nvalue that is going to be dropped without further use."##, | 6304 | description: r##"Checks for a redundant `clone()` (and its relatives) which clones an owned\nvalue that is going to be dropped without further use."##, |
5762 | }, | 6305 | }, |
5763 | LintCompletion { | 6306 | Lint { |
5764 | label: "clippy::redundant_closure", | 6307 | label: "clippy::redundant_closure", |
5765 | description: r##"Checks for closures which just call another function where\nthe function can be called directly. `unsafe` functions or calls where types\nget adjusted are ignored."##, | 6308 | description: r##"Checks for closures which just call another function where\nthe function can be called directly. `unsafe` functions or calls where types\nget adjusted are ignored."##, |
5766 | }, | 6309 | }, |
5767 | LintCompletion { | 6310 | Lint { |
5768 | label: "clippy::redundant_closure_call", | 6311 | label: "clippy::redundant_closure_call", |
5769 | description: r##"Detects closures called in the same expression where they\nare defined."##, | 6312 | description: r##"Detects closures called in the same expression where they\nare defined."##, |
5770 | }, | 6313 | }, |
5771 | LintCompletion { | 6314 | Lint { |
5772 | label: "clippy::redundant_closure_for_method_calls", | 6315 | label: "clippy::redundant_closure_for_method_calls", |
5773 | description: r##"Checks for closures which only invoke a method on the closure\nargument and can be replaced by referencing the method directly."##, | 6316 | description: r##"Checks for closures which only invoke a method on the closure\nargument and can be replaced by referencing the method directly."##, |
5774 | }, | 6317 | }, |
5775 | LintCompletion { | 6318 | Lint { |
5776 | label: "clippy::redundant_else", | 6319 | label: "clippy::redundant_else", |
5777 | description: r##"Checks for `else` blocks that can be removed without changing semantics."##, | 6320 | description: r##"Checks for `else` blocks that can be removed without changing semantics."##, |
5778 | }, | 6321 | }, |
5779 | LintCompletion { | 6322 | Lint { |
5780 | label: "clippy::redundant_field_names", | 6323 | label: "clippy::redundant_field_names", |
5781 | description: r##"Checks for fields in struct literals where shorthands\ncould be used."##, | 6324 | description: r##"Checks for fields in struct literals where shorthands\ncould be used."##, |
5782 | }, | 6325 | }, |
5783 | LintCompletion { | 6326 | Lint { |
5784 | label: "clippy::redundant_pattern", | 6327 | label: "clippy::redundant_pattern", |
5785 | description: r##"Checks for patterns in the form `name @ _`."##, | 6328 | description: r##"Checks for patterns in the form `name @ _`."##, |
5786 | }, | 6329 | }, |
5787 | LintCompletion { | 6330 | Lint { |
5788 | label: "clippy::redundant_pattern_matching", | 6331 | label: "clippy::redundant_pattern_matching", |
5789 | description: r##"Lint for redundant pattern matching over `Result`, `Option`,\n`std::task::Poll` or `std::net::IpAddr`"##, | 6332 | description: r##"Lint for redundant pattern matching over `Result`, `Option`,\n`std::task::Poll` or `std::net::IpAddr`"##, |
5790 | }, | 6333 | }, |
5791 | LintCompletion { | 6334 | Lint { |
5792 | label: "clippy::redundant_pub_crate", | 6335 | label: "clippy::redundant_pub_crate", |
5793 | description: r##"Checks for items declared `pub(crate)` that are not crate visible because they\nare inside a private module."##, | 6336 | description: r##"Checks for items declared `pub(crate)` that are not crate visible because they\nare inside a private module."##, |
5794 | }, | 6337 | }, |
5795 | LintCompletion { | 6338 | Lint { |
5796 | label: "clippy::redundant_slicing", | 6339 | label: "clippy::redundant_slicing", |
5797 | description: r##"Checks for redundant slicing expressions which use the full range, and\ndo not change the type."##, | 6340 | description: r##"Checks for redundant slicing expressions which use the full range, and\ndo not change the type."##, |
5798 | }, | 6341 | }, |
5799 | LintCompletion { | 6342 | Lint { |
5800 | label: "clippy::redundant_static_lifetimes", | 6343 | label: "clippy::redundant_static_lifetimes", |
5801 | description: r##"Checks for constants and statics with an explicit `'static` lifetime."##, | 6344 | description: r##"Checks for constants and statics with an explicit `'static` lifetime."##, |
5802 | }, | 6345 | }, |
5803 | LintCompletion { | 6346 | Lint { |
6347 | label: "clippy::ref_binding_to_reference", | ||
6348 | description: r##"Checks for `ref` bindings which create a reference to a reference."##, | ||
6349 | }, | ||
6350 | Lint { | ||
5804 | label: "clippy::ref_in_deref", | 6351 | label: "clippy::ref_in_deref", |
5805 | description: r##"Checks for references in expressions that use\nauto dereference."##, | 6352 | description: r##"Checks for references in expressions that use\nauto dereference."##, |
5806 | }, | 6353 | }, |
5807 | LintCompletion { | 6354 | Lint { |
5808 | label: "clippy::ref_option_ref", | 6355 | label: "clippy::ref_option_ref", |
5809 | description: r##"Checks for usage of `&Option<&T>`."##, | 6356 | description: r##"Checks for usage of `&Option<&T>`."##, |
5810 | }, | 6357 | }, |
5811 | LintCompletion { | 6358 | Lint { |
5812 | label: "clippy::regex_macro", | 6359 | label: "clippy::regex_macro", |
5813 | description: r##"Nothing. This lint has been deprecated."##, | 6360 | description: r##"Nothing. This lint has been deprecated."##, |
5814 | }, | 6361 | }, |
5815 | LintCompletion { | 6362 | Lint { |
5816 | label: "clippy::repeat_once", | 6363 | label: "clippy::repeat_once", |
5817 | description: r##"Checks for usage of `.repeat(1)` and suggest the following method for each types.\n- `.to_string()` for `str`\n- `.clone()` for `String`\n- `.to_vec()` for `slice`"##, | 6364 | description: r##"Checks for usage of `.repeat(1)` and suggest the following method for each types.\n- `.to_string()` for `str`\n- `.clone()` for `String`\n- `.to_vec()` for `slice`"##, |
5818 | }, | 6365 | }, |
5819 | LintCompletion { | 6366 | Lint { |
5820 | label: "clippy::replace_consts", | 6367 | label: "clippy::replace_consts", |
5821 | description: r##"Nothing. This lint has been deprecated."##, | 6368 | description: r##"Nothing. This lint has been deprecated."##, |
5822 | }, | 6369 | }, |
5823 | LintCompletion { | 6370 | Lint { |
5824 | label: "clippy::rest_pat_in_fully_bound_structs", | 6371 | label: "clippy::rest_pat_in_fully_bound_structs", |
5825 | description: r##"Checks for unnecessary '..' pattern binding on struct when all fields are explicitly matched."##, | 6372 | description: r##"Checks for unnecessary '..' pattern binding on struct when all fields are explicitly matched."##, |
5826 | }, | 6373 | }, |
5827 | LintCompletion { | 6374 | Lint { |
5828 | label: "clippy::result_map_or_into_option", | 6375 | label: "clippy::result_map_or_into_option", |
5829 | description: r##"Checks for usage of `_.map_or(None, Some)`."##, | 6376 | description: r##"Checks for usage of `_.map_or(None, Some)`."##, |
5830 | }, | 6377 | }, |
5831 | LintCompletion { | 6378 | Lint { |
5832 | label: "clippy::result_map_unit_fn", | 6379 | label: "clippy::result_map_unit_fn", |
5833 | description: r##"Checks for usage of `result.map(f)` where f is a function\nor closure that returns the unit type `()`."##, | 6380 | description: r##"Checks for usage of `result.map(f)` where f is a function\nor closure that returns the unit type `()`."##, |
5834 | }, | 6381 | }, |
5835 | LintCompletion { | 6382 | Lint { |
5836 | label: "clippy::result_unit_err", | 6383 | label: "clippy::result_unit_err", |
5837 | description: r##"Checks for public functions that return a `Result`\nwith an `Err` type of `()`. It suggests using a custom type that\nimplements [`std::error::Error`]."##, | 6384 | description: r##"Checks for public functions that return a `Result`\nwith an `Err` type of `()`. It suggests using a custom type that\nimplements `std::error::Error`."##, |
5838 | }, | 6385 | }, |
5839 | LintCompletion { | 6386 | Lint { |
5840 | label: "clippy::reversed_empty_ranges", | 6387 | label: "clippy::reversed_empty_ranges", |
5841 | description: r##"Checks for range expressions `x..y` where both `x` and `y`\nare constant and `x` is greater or equal to `y`."##, | 6388 | description: r##"Checks for range expressions `x..y` where both `x` and `y`\nare constant and `x` is greater or equal to `y`."##, |
5842 | }, | 6389 | }, |
5843 | LintCompletion { | 6390 | Lint { |
5844 | label: "clippy::same_functions_in_if_condition", | 6391 | label: "clippy::same_functions_in_if_condition", |
5845 | description: r##"Checks for consecutive `if`s with the same function call."##, | 6392 | description: r##"Checks for consecutive `if`s with the same function call."##, |
5846 | }, | 6393 | }, |
5847 | LintCompletion { | 6394 | Lint { |
5848 | label: "clippy::same_item_push", | 6395 | label: "clippy::same_item_push", |
5849 | description: r##"Checks whether a for loop is being used to push a constant\nvalue into a Vec."##, | 6396 | description: r##"Checks whether a for loop is being used to push a constant\nvalue into a Vec."##, |
5850 | }, | 6397 | }, |
5851 | LintCompletion { | 6398 | Lint { |
5852 | label: "clippy::search_is_some", | 6399 | label: "clippy::search_is_some", |
5853 | description: r##"Checks for an iterator or string search (such as `find()`,\n`position()`, or `rposition()`) followed by a call to `is_some()`."##, | 6400 | description: r##"Checks for an iterator or string search (such as `find()`,\n`position()`, or `rposition()`) followed by a call to `is_some()` or `is_none()`."##, |
5854 | }, | 6401 | }, |
5855 | LintCompletion { | 6402 | Lint { |
5856 | label: "clippy::self_assignment", | 6403 | label: "clippy::self_assignment", |
5857 | description: r##"Checks for explicit self-assignments."##, | 6404 | description: r##"Checks for explicit self-assignments."##, |
5858 | }, | 6405 | }, |
5859 | LintCompletion { | 6406 | Lint { |
5860 | label: "clippy::semicolon_if_nothing_returned", | 6407 | label: "clippy::semicolon_if_nothing_returned", |
5861 | description: r##"Looks for blocks of expressions and fires if the last expression returns `()`\nbut is not followed by a semicolon."##, | 6408 | description: r##"Looks for blocks of expressions and fires if the last expression returns\n`()` but is not followed by a semicolon."##, |
5862 | }, | 6409 | }, |
5863 | LintCompletion { | 6410 | Lint { |
5864 | label: "clippy::serde_api_misuse", | 6411 | label: "clippy::serde_api_misuse", |
5865 | description: r##"Checks for mis-uses of the serde API."##, | 6412 | description: r##"Checks for mis-uses of the serde API."##, |
5866 | }, | 6413 | }, |
5867 | LintCompletion { | 6414 | Lint { |
5868 | label: "clippy::shadow_reuse", | 6415 | label: "clippy::shadow_reuse", |
5869 | description: r##"Checks for bindings that shadow other bindings already in\nscope, while reusing the original value."##, | 6416 | description: r##"Checks for bindings that shadow other bindings already in\nscope, while reusing the original value."##, |
5870 | }, | 6417 | }, |
5871 | LintCompletion { | 6418 | Lint { |
5872 | label: "clippy::shadow_same", | 6419 | label: "clippy::shadow_same", |
5873 | description: r##"Checks for bindings that shadow other bindings already in\nscope, while just changing reference level or mutability."##, | 6420 | description: r##"Checks for bindings that shadow other bindings already in\nscope, while just changing reference level or mutability."##, |
5874 | }, | 6421 | }, |
5875 | LintCompletion { | 6422 | Lint { |
5876 | label: "clippy::shadow_unrelated", | 6423 | label: "clippy::shadow_unrelated", |
5877 | description: r##"Checks for bindings that shadow other bindings already in\nscope, either without a initialization or with one that does not even use\nthe original value."##, | 6424 | description: r##"Checks for bindings that shadow other bindings already in\nscope, either without a initialization or with one that does not even use\nthe original value."##, |
5878 | }, | 6425 | }, |
5879 | LintCompletion { | 6426 | Lint { |
5880 | label: "clippy::short_circuit_statement", | 6427 | label: "clippy::short_circuit_statement", |
5881 | description: r##"Checks for the use of short circuit boolean conditions as\na\nstatement."##, | 6428 | description: r##"Checks for the use of short circuit boolean conditions as\na\nstatement."##, |
5882 | }, | 6429 | }, |
5883 | LintCompletion { | 6430 | Lint { |
5884 | label: "clippy::should_assert_eq", | 6431 | label: "clippy::should_assert_eq", |
5885 | description: r##"Nothing. This lint has been deprecated."##, | 6432 | description: r##"Nothing. This lint has been deprecated."##, |
5886 | }, | 6433 | }, |
5887 | LintCompletion { | 6434 | Lint { |
5888 | label: "clippy::should_implement_trait", | 6435 | label: "clippy::should_implement_trait", |
5889 | description: r##"Checks for methods that should live in a trait\nimplementation of a `std` trait (see [llogiq's blog\npost](http://llogiq.github.io/2015/07/30/traits.html) for further\ninformation) instead of an inherent implementation."##, | 6436 | description: r##"Checks for methods that should live in a trait\nimplementation of a `std` trait (see [llogiq's blog\npost](http://llogiq.github.io/2015/07/30/traits.html) for further\ninformation) instead of an inherent implementation."##, |
5890 | }, | 6437 | }, |
5891 | LintCompletion { | 6438 | Lint { |
5892 | label: "clippy::similar_names", | 6439 | label: "clippy::similar_names", |
5893 | description: r##"Checks for names that are very similar and thus confusing."##, | 6440 | description: r##"Checks for names that are very similar and thus confusing."##, |
5894 | }, | 6441 | }, |
5895 | LintCompletion { | 6442 | Lint { |
5896 | label: "clippy::single_char_add_str", | 6443 | label: "clippy::single_char_add_str", |
5897 | description: r##"Warns when using `push_str`/`insert_str` with a single-character string literal\nwhere `push`/`insert` with a `char` would work fine."##, | 6444 | description: r##"Warns when using `push_str`/`insert_str` with a single-character string literal\nwhere `push`/`insert` with a `char` would work fine."##, |
5898 | }, | 6445 | }, |
5899 | LintCompletion { | 6446 | Lint { |
5900 | label: "clippy::single_char_pattern", | 6447 | label: "clippy::single_char_pattern", |
5901 | description: r##"Checks for string methods that receive a single-character\n`str` as an argument, e.g., `_.split(\"x\")`."##, | 6448 | description: r##"Checks for string methods that receive a single-character\n`str` as an argument, e.g., `_.split(\"x\")`."##, |
5902 | }, | 6449 | }, |
5903 | LintCompletion { | 6450 | Lint { |
5904 | label: "clippy::single_component_path_imports", | 6451 | label: "clippy::single_component_path_imports", |
5905 | description: r##"Checking for imports with single component use path."##, | 6452 | description: r##"Checking for imports with single component use path."##, |
5906 | }, | 6453 | }, |
5907 | LintCompletion { | 6454 | Lint { |
5908 | label: "clippy::single_element_loop", | 6455 | label: "clippy::single_element_loop", |
5909 | description: r##"Checks whether a for loop has a single element."##, | 6456 | description: r##"Checks whether a for loop has a single element."##, |
5910 | }, | 6457 | }, |
5911 | LintCompletion { | 6458 | Lint { |
5912 | label: "clippy::single_match", | 6459 | label: "clippy::single_match", |
5913 | description: r##"Checks for matches with a single arm where an `if let`\nwill usually suffice."##, | 6460 | description: r##"Checks for matches with a single arm where an `if let`\nwill usually suffice."##, |
5914 | }, | 6461 | }, |
5915 | LintCompletion { | 6462 | Lint { |
5916 | label: "clippy::single_match_else", | 6463 | label: "clippy::single_match_else", |
5917 | description: r##"Checks for matches with two arms where an `if let else` will\nusually suffice."##, | 6464 | description: r##"Checks for matches with two arms where an `if let else` will\nusually suffice."##, |
5918 | }, | 6465 | }, |
5919 | LintCompletion { | 6466 | Lint { |
5920 | label: "clippy::size_of_in_element_count", | 6467 | label: "clippy::size_of_in_element_count", |
5921 | description: r##"Detects expressions where\n`size_of::<T>` or `size_of_val::<T>` is used as a\ncount of elements of type `T`"##, | 6468 | description: r##"Detects expressions where\n`size_of::<T>` or `size_of_val::<T>` is used as a\ncount of elements of type `T`"##, |
5922 | }, | 6469 | }, |
5923 | LintCompletion { | 6470 | Lint { |
5924 | label: "clippy::skip_while_next", | 6471 | label: "clippy::skip_while_next", |
5925 | description: r##"Checks for usage of `_.skip_while(condition).next()`."##, | 6472 | description: r##"Checks for usage of `_.skip_while(condition).next()`."##, |
5926 | }, | 6473 | }, |
5927 | LintCompletion { | 6474 | Lint { |
5928 | label: "clippy::slow_vector_initialization", | 6475 | label: "clippy::slow_vector_initialization", |
5929 | description: r##"Checks slow zero-filled vector initialization"##, | 6476 | description: r##"Checks slow zero-filled vector initialization"##, |
5930 | }, | 6477 | }, |
5931 | LintCompletion { | 6478 | Lint { |
5932 | label: "clippy::stable_sort_primitive", | 6479 | label: "clippy::stable_sort_primitive", |
5933 | description: r##"When sorting primitive values (integers, bools, chars, as well\nas arrays, slices, and tuples of such items), it is better to\nuse an unstable sort than a stable sort."##, | 6480 | description: r##"When sorting primitive values (integers, bools, chars, as well\nas arrays, slices, and tuples of such items), it is better to\nuse an unstable sort than a stable sort."##, |
5934 | }, | 6481 | }, |
5935 | LintCompletion { | 6482 | Lint { |
5936 | label: "clippy::str_to_string", | 6483 | label: "clippy::str_to_string", |
5937 | description: r##"This lint checks for `.to_string()` method calls on values of type `&str`."##, | 6484 | description: r##"This lint checks for `.to_string()` method calls on values of type `&str`."##, |
5938 | }, | 6485 | }, |
5939 | LintCompletion { | 6486 | Lint { |
5940 | label: "clippy::string_add", | 6487 | label: "clippy::string_add", |
5941 | description: r##"Checks for all instances of `x + _` where `x` is of type\n`String`, but only if [`string_add_assign`](#string_add_assign) does *not*\nmatch."##, | 6488 | description: r##"Checks for all instances of `x + _` where `x` is of type\n`String`, but only if [`string_add_assign`](#string_add_assign) does *not*\nmatch."##, |
5942 | }, | 6489 | }, |
5943 | LintCompletion { | 6490 | Lint { |
5944 | label: "clippy::string_add_assign", | 6491 | label: "clippy::string_add_assign", |
5945 | description: r##"Checks for string appends of the form `x = x + y` (without\n`let`!)."##, | 6492 | description: r##"Checks for string appends of the form `x = x + y` (without\n`let`!)."##, |
5946 | }, | 6493 | }, |
5947 | LintCompletion { | 6494 | Lint { |
5948 | label: "clippy::string_extend_chars", | 6495 | label: "clippy::string_extend_chars", |
5949 | description: r##"Checks for the use of `.extend(s.chars())` where s is a\n`&str` or `String`."##, | 6496 | description: r##"Checks for the use of `.extend(s.chars())` where s is a\n`&str` or `String`."##, |
5950 | }, | 6497 | }, |
5951 | LintCompletion { | 6498 | Lint { |
5952 | label: "clippy::string_from_utf8_as_bytes", | 6499 | label: "clippy::string_from_utf8_as_bytes", |
5953 | description: r##"Check if the string is transformed to byte array and casted back to string."##, | 6500 | description: r##"Check if the string is transformed to byte array and casted back to string."##, |
5954 | }, | 6501 | }, |
5955 | LintCompletion { | 6502 | Lint { |
5956 | label: "clippy::string_lit_as_bytes", | 6503 | label: "clippy::string_lit_as_bytes", |
5957 | description: r##"Checks for the `as_bytes` method called on string literals\nthat contain only ASCII characters."##, | 6504 | description: r##"Checks for the `as_bytes` method called on string literals\nthat contain only ASCII characters."##, |
5958 | }, | 6505 | }, |
5959 | LintCompletion { | 6506 | Lint { |
5960 | label: "clippy::string_to_string", | 6507 | label: "clippy::string_to_string", |
5961 | description: r##"This lint checks for `.to_string()` method calls on values of type `String`."##, | 6508 | description: r##"This lint checks for `.to_string()` method calls on values of type `String`."##, |
5962 | }, | 6509 | }, |
5963 | LintCompletion { | 6510 | Lint { |
5964 | label: "clippy::struct_excessive_bools", | 6511 | label: "clippy::struct_excessive_bools", |
5965 | description: r##"Checks for excessive\nuse of bools in structs."##, | 6512 | description: r##"Checks for excessive\nuse of bools in structs."##, |
5966 | }, | 6513 | }, |
5967 | LintCompletion { | 6514 | Lint { |
5968 | label: "clippy::suboptimal_flops", | 6515 | label: "clippy::suboptimal_flops", |
5969 | description: r##"Looks for floating-point expressions that\ncan be expressed using built-in methods to improve both\naccuracy and performance."##, | 6516 | description: r##"Looks for floating-point expressions that\ncan be expressed using built-in methods to improve both\naccuracy and performance."##, |
5970 | }, | 6517 | }, |
5971 | LintCompletion { | 6518 | Lint { |
5972 | label: "clippy::suspicious_arithmetic_impl", | 6519 | label: "clippy::suspicious_arithmetic_impl", |
5973 | description: r##"Lints for suspicious operations in impls of arithmetic operators, e.g.\nsubtracting elements in an Add impl."##, | 6520 | description: r##"Lints for suspicious operations in impls of arithmetic operators, e.g.\nsubtracting elements in an Add impl."##, |
5974 | }, | 6521 | }, |
5975 | LintCompletion { | 6522 | Lint { |
5976 | label: "clippy::suspicious_assignment_formatting", | 6523 | label: "clippy::suspicious_assignment_formatting", |
5977 | description: r##"Checks for use of the non-existent `=*`, `=!` and `=-`\noperators."##, | 6524 | description: r##"Checks for use of the non-existent `=*`, `=!` and `=-`\noperators."##, |
5978 | }, | 6525 | }, |
5979 | LintCompletion { | 6526 | Lint { |
5980 | label: "clippy::suspicious_else_formatting", | 6527 | label: "clippy::suspicious_else_formatting", |
5981 | description: r##"Checks for formatting of `else`. It lints if the `else`\nis followed immediately by a newline or the `else` seems to be missing."##, | 6528 | description: r##"Checks for formatting of `else`. It lints if the `else`\nis followed immediately by a newline or the `else` seems to be missing."##, |
5982 | }, | 6529 | }, |
5983 | LintCompletion { | 6530 | Lint { |
5984 | label: "clippy::suspicious_map", | 6531 | label: "clippy::suspicious_map", |
5985 | description: r##"Checks for calls to `map` followed by a `count`."##, | 6532 | description: r##"Checks for calls to `map` followed by a `count`."##, |
5986 | }, | 6533 | }, |
5987 | LintCompletion { | 6534 | Lint { |
5988 | label: "clippy::suspicious_op_assign_impl", | 6535 | label: "clippy::suspicious_op_assign_impl", |
5989 | description: r##"Lints for suspicious operations in impls of OpAssign, e.g.\nsubtracting elements in an AddAssign impl."##, | 6536 | description: r##"Lints for suspicious operations in impls of OpAssign, e.g.\nsubtracting elements in an AddAssign impl."##, |
5990 | }, | 6537 | }, |
5991 | LintCompletion { | 6538 | Lint { |
5992 | label: "clippy::suspicious_operation_groupings", | 6539 | label: "clippy::suspicious_operation_groupings", |
5993 | description: r##"Checks for unlikely usages of binary operators that are almost\ncertainly typos and/or copy/paste errors, given the other usages\nof binary operators nearby."##, | 6540 | description: r##"Checks for unlikely usages of binary operators that are almost\ncertainly typos and/or copy/paste errors, given the other usages\nof binary operators nearby."##, |
5994 | }, | 6541 | }, |
5995 | LintCompletion { | 6542 | Lint { |
6543 | label: "clippy::suspicious_splitn", | ||
6544 | description: r##"Checks for calls to [`splitn`]\n(https://doc.rust-lang.org/std/primitive.str.html#method.splitn) and\nrelated functions with either zero or one splits."##, | ||
6545 | }, | ||
6546 | Lint { | ||
5996 | label: "clippy::suspicious_unary_op_formatting", | 6547 | label: "clippy::suspicious_unary_op_formatting", |
5997 | description: r##"Checks the formatting of a unary operator on the right hand side\nof a binary operator. It lints if there is no space between the binary and unary operators,\nbut there is a space between the unary and its operand."##, | 6548 | description: r##"Checks the formatting of a unary operator on the right hand side\nof a binary operator. It lints if there is no space between the binary and unary operators,\nbut there is a space between the unary and its operand."##, |
5998 | }, | 6549 | }, |
5999 | LintCompletion { | 6550 | Lint { |
6000 | label: "clippy::tabs_in_doc_comments", | 6551 | label: "clippy::tabs_in_doc_comments", |
6001 | description: r##"Checks doc comments for usage of tab characters."##, | 6552 | description: r##"Checks doc comments for usage of tab characters."##, |
6002 | }, | 6553 | }, |
6003 | LintCompletion { | 6554 | Lint { |
6004 | label: "clippy::temporary_assignment", | 6555 | label: "clippy::temporary_assignment", |
6005 | description: r##"Checks for construction of a structure or tuple just to\nassign a value in it."##, | 6556 | description: r##"Checks for construction of a structure or tuple just to\nassign a value in it."##, |
6006 | }, | 6557 | }, |
6007 | LintCompletion { | 6558 | Lint { |
6008 | label: "clippy::temporary_cstring_as_ptr", | ||
6009 | description: r##"Nothing. This lint has been deprecated."##, | ||
6010 | }, | ||
6011 | LintCompletion { | ||
6012 | label: "clippy::to_digit_is_some", | 6559 | label: "clippy::to_digit_is_some", |
6013 | description: r##"Checks for `.to_digit(..).is_some()` on `char`s."##, | 6560 | description: r##"Checks for `.to_digit(..).is_some()` on `char`s."##, |
6014 | }, | 6561 | }, |
6015 | LintCompletion { | 6562 | Lint { |
6016 | label: "clippy::to_string_in_display", | 6563 | label: "clippy::to_string_in_display", |
6017 | description: r##"Checks for uses of `to_string()` in `Display` traits."##, | 6564 | description: r##"Checks for uses of `to_string()` in `Display` traits."##, |
6018 | }, | 6565 | }, |
6019 | LintCompletion { label: "clippy::todo", description: r##"Checks for usage of `todo!`."## }, | 6566 | Lint { label: "clippy::todo", description: r##"Checks for usage of `todo!`."## }, |
6020 | LintCompletion { | 6567 | Lint { |
6021 | label: "clippy::too_many_arguments", | 6568 | label: "clippy::too_many_arguments", |
6022 | description: r##"Checks for functions with too many parameters."##, | 6569 | description: r##"Checks for functions with too many parameters."##, |
6023 | }, | 6570 | }, |
6024 | LintCompletion { | 6571 | Lint { |
6025 | label: "clippy::too_many_lines", | 6572 | label: "clippy::too_many_lines", |
6026 | description: r##"Checks for functions with a large amount of lines."##, | 6573 | description: r##"Checks for functions with a large amount of lines."##, |
6027 | }, | 6574 | }, |
6028 | LintCompletion { | 6575 | Lint { |
6029 | label: "clippy::toplevel_ref_arg", | 6576 | label: "clippy::toplevel_ref_arg", |
6030 | description: r##"Checks for function arguments and let bindings denoted as\n`ref`."##, | 6577 | description: r##"Checks for function arguments and let bindings denoted as\n`ref`."##, |
6031 | }, | 6578 | }, |
6032 | LintCompletion { | 6579 | Lint { |
6033 | label: "clippy::trait_duplication_in_bounds", | 6580 | label: "clippy::trait_duplication_in_bounds", |
6034 | description: r##"Checks for cases where generics are being used and multiple\nsyntax specifications for trait bounds are used simultaneously."##, | 6581 | description: r##"Checks for cases where generics are being used and multiple\nsyntax specifications for trait bounds are used simultaneously."##, |
6035 | }, | 6582 | }, |
6036 | LintCompletion { | 6583 | Lint { |
6037 | label: "clippy::transmute_bytes_to_str", | 6584 | label: "clippy::transmute_bytes_to_str", |
6038 | description: r##"Checks for transmutes from a `&[u8]` to a `&str`."##, | 6585 | description: r##"Checks for transmutes from a `&[u8]` to a `&str`."##, |
6039 | }, | 6586 | }, |
6040 | LintCompletion { | 6587 | Lint { |
6041 | label: "clippy::transmute_float_to_int", | 6588 | label: "clippy::transmute_float_to_int", |
6042 | description: r##"Checks for transmutes from a float to an integer."##, | 6589 | description: r##"Checks for transmutes from a float to an integer."##, |
6043 | }, | 6590 | }, |
6044 | LintCompletion { | 6591 | Lint { |
6045 | label: "clippy::transmute_int_to_bool", | 6592 | label: "clippy::transmute_int_to_bool", |
6046 | description: r##"Checks for transmutes from an integer to a `bool`."##, | 6593 | description: r##"Checks for transmutes from an integer to a `bool`."##, |
6047 | }, | 6594 | }, |
6048 | LintCompletion { | 6595 | Lint { |
6049 | label: "clippy::transmute_int_to_char", | 6596 | label: "clippy::transmute_int_to_char", |
6050 | description: r##"Checks for transmutes from an integer to a `char`."##, | 6597 | description: r##"Checks for transmutes from an integer to a `char`."##, |
6051 | }, | 6598 | }, |
6052 | LintCompletion { | 6599 | Lint { |
6053 | label: "clippy::transmute_int_to_float", | 6600 | label: "clippy::transmute_int_to_float", |
6054 | description: r##"Checks for transmutes from an integer to a float."##, | 6601 | description: r##"Checks for transmutes from an integer to a float."##, |
6055 | }, | 6602 | }, |
6056 | LintCompletion { | 6603 | Lint { |
6057 | label: "clippy::transmute_ptr_to_ptr", | 6604 | label: "clippy::transmute_ptr_to_ptr", |
6058 | description: r##"Checks for transmutes from a pointer to a pointer, or\nfrom a reference to a reference."##, | 6605 | description: r##"Checks for transmutes from a pointer to a pointer, or\nfrom a reference to a reference."##, |
6059 | }, | 6606 | }, |
6060 | LintCompletion { | 6607 | Lint { |
6061 | label: "clippy::transmute_ptr_to_ref", | 6608 | label: "clippy::transmute_ptr_to_ref", |
6062 | description: r##"Checks for transmutes from a pointer to a reference."##, | 6609 | description: r##"Checks for transmutes from a pointer to a reference."##, |
6063 | }, | 6610 | }, |
6064 | LintCompletion { | 6611 | Lint { |
6065 | label: "clippy::transmutes_expressible_as_ptr_casts", | 6612 | label: "clippy::transmutes_expressible_as_ptr_casts", |
6066 | description: r##"Checks for transmutes that could be a pointer cast."##, | 6613 | description: r##"Checks for transmutes that could be a pointer cast."##, |
6067 | }, | 6614 | }, |
6068 | LintCompletion { | 6615 | Lint { |
6069 | label: "clippy::transmuting_null", | 6616 | label: "clippy::transmuting_null", |
6070 | description: r##"Checks for transmute calls which would receive a null pointer."##, | 6617 | description: r##"Checks for transmute calls which would receive a null pointer."##, |
6071 | }, | 6618 | }, |
6072 | LintCompletion { | 6619 | Lint { |
6073 | label: "clippy::trivial_regex", | 6620 | label: "clippy::trivial_regex", |
6074 | description: r##"Checks for trivial [regex](https://crates.io/crates/regex)\ncreation (with `Regex::new`, `RegexBuilder::new`, or `RegexSet::new`)."##, | 6621 | description: r##"Checks for trivial [regex](https://crates.io/crates/regex)\ncreation (with `Regex::new`, `RegexBuilder::new`, or `RegexSet::new`)."##, |
6075 | }, | 6622 | }, |
6076 | LintCompletion { | 6623 | Lint { |
6077 | label: "clippy::trivially_copy_pass_by_ref", | 6624 | label: "clippy::trivially_copy_pass_by_ref", |
6078 | description: r##"Checks for functions taking arguments by reference, where\nthe argument type is `Copy` and small enough to be more efficient to always\npass by value."##, | 6625 | description: r##"Checks for functions taking arguments by reference, where\nthe argument type is `Copy` and small enough to be more efficient to always\npass by value."##, |
6079 | }, | 6626 | }, |
6080 | LintCompletion { | 6627 | Lint { label: "clippy::try_err", description: r##"Checks for usages of `Err(x)?`."## }, |
6081 | label: "clippy::try_err", | 6628 | Lint { |
6082 | description: r##"Checks for usages of `Err(x)?`."##, | ||
6083 | }, | ||
6084 | LintCompletion { | ||
6085 | label: "clippy::type_complexity", | 6629 | label: "clippy::type_complexity", |
6086 | description: r##"Checks for types used in structs, parameters and `let`\ndeclarations above a certain complexity threshold."##, | 6630 | description: r##"Checks for types used in structs, parameters and `let`\ndeclarations above a certain complexity threshold."##, |
6087 | }, | 6631 | }, |
6088 | LintCompletion { | 6632 | Lint { |
6089 | label: "clippy::type_repetition_in_bounds", | 6633 | label: "clippy::type_repetition_in_bounds", |
6090 | description: r##"This lint warns about unnecessary type repetitions in trait bounds"##, | 6634 | description: r##"This lint warns about unnecessary type repetitions in trait bounds"##, |
6091 | }, | 6635 | }, |
6092 | LintCompletion { | 6636 | Lint { |
6093 | label: "clippy::undropped_manually_drops", | 6637 | label: "clippy::undropped_manually_drops", |
6094 | description: r##"Prevents the safe `std::mem::drop` function from being called on `std::mem::ManuallyDrop`."##, | 6638 | description: r##"Prevents the safe `std::mem::drop` function from being called on `std::mem::ManuallyDrop`."##, |
6095 | }, | 6639 | }, |
6096 | LintCompletion { | 6640 | Lint { |
6097 | label: "clippy::unicode_not_nfc", | 6641 | label: "clippy::unicode_not_nfc", |
6098 | description: r##"Checks for string literals that contain Unicode in a form\nthat is not equal to its\n[NFC-recomposition](http://www.unicode.org/reports/tr15/#Norm_Forms)."##, | 6642 | description: r##"Checks for string literals that contain Unicode in a form\nthat is not equal to its\n[NFC-recomposition](http://www.unicode.org/reports/tr15/#Norm_Forms)."##, |
6099 | }, | 6643 | }, |
6100 | LintCompletion { | 6644 | Lint { |
6101 | label: "clippy::unimplemented", | 6645 | label: "clippy::unimplemented", |
6102 | description: r##"Checks for usage of `unimplemented!`."##, | 6646 | description: r##"Checks for usage of `unimplemented!`."##, |
6103 | }, | 6647 | }, |
6104 | LintCompletion { | 6648 | Lint { |
6105 | label: "clippy::uninit_assumed_init", | 6649 | label: "clippy::uninit_assumed_init", |
6106 | description: r##"Checks for `MaybeUninit::uninit().assume_init()`."##, | 6650 | description: r##"Checks for `MaybeUninit::uninit().assume_init()`."##, |
6107 | }, | 6651 | }, |
6108 | LintCompletion { | 6652 | Lint { |
6109 | label: "clippy::unit_arg", | 6653 | label: "clippy::unit_arg", |
6110 | description: r##"Checks for passing a unit value as an argument to a function without using a\nunit literal (`()`)."##, | 6654 | description: r##"Checks for passing a unit value as an argument to a function without using a\nunit literal (`()`)."##, |
6111 | }, | 6655 | }, |
6112 | LintCompletion { | 6656 | Lint { |
6113 | label: "clippy::unit_cmp", | 6657 | label: "clippy::unit_cmp", |
6114 | description: r##"Checks for comparisons to unit. This includes all binary\ncomparisons (like `==` and `<`) and asserts."##, | 6658 | description: r##"Checks for comparisons to unit. This includes all binary\ncomparisons (like `==` and `<`) and asserts."##, |
6115 | }, | 6659 | }, |
6116 | LintCompletion { | 6660 | Lint { |
6117 | label: "clippy::unit_return_expecting_ord", | 6661 | label: "clippy::unit_return_expecting_ord", |
6118 | description: r##"Checks for functions that expect closures of type\nFn(...) -> Ord where the implemented closure returns the unit type.\nThe lint also suggests to remove the semi-colon at the end of the statement if present."##, | 6662 | description: r##"Checks for functions that expect closures of type\nFn(...) -> Ord where the implemented closure returns the unit type.\nThe lint also suggests to remove the semi-colon at the end of the statement if present."##, |
6119 | }, | 6663 | }, |
6120 | LintCompletion { | 6664 | Lint { |
6121 | label: "clippy::unknown_clippy_lints", | ||
6122 | description: r##"Nothing. This lint has been deprecated."##, | ||
6123 | }, | ||
6124 | LintCompletion { | ||
6125 | label: "clippy::unnecessary_cast", | 6665 | label: "clippy::unnecessary_cast", |
6126 | description: r##"Checks for casts to the same type, casts of int literals to integer types\nand casts of float literals to float types."##, | 6666 | description: r##"Checks for casts to the same type, casts of int literals to integer types\nand casts of float literals to float types."##, |
6127 | }, | 6667 | }, |
6128 | LintCompletion { | 6668 | Lint { |
6129 | label: "clippy::unnecessary_filter_map", | 6669 | label: "clippy::unnecessary_filter_map", |
6130 | description: r##"Checks for `filter_map` calls which could be replaced by `filter` or `map`.\nMore specifically it checks if the closure provided is only performing one of the\nfilter or map operations and suggests the appropriate option."##, | 6670 | description: r##"Checks for `filter_map` calls which could be replaced by `filter` or `map`.\nMore specifically it checks if the closure provided is only performing one of the\nfilter or map operations and suggests the appropriate option."##, |
6131 | }, | 6671 | }, |
6132 | LintCompletion { | 6672 | Lint { |
6133 | label: "clippy::unnecessary_fold", | 6673 | label: "clippy::unnecessary_fold", |
6134 | description: r##"Checks for using `fold` when a more succinct alternative exists.\nSpecifically, this checks for `fold`s which could be replaced by `any`, `all`,\n`sum` or `product`."##, | 6674 | description: r##"Checks for using `fold` when a more succinct alternative exists.\nSpecifically, this checks for `fold`s which could be replaced by `any`, `all`,\n`sum` or `product`."##, |
6135 | }, | 6675 | }, |
6136 | LintCompletion { | 6676 | Lint { |
6137 | label: "clippy::unnecessary_lazy_evaluations", | 6677 | label: "clippy::unnecessary_lazy_evaluations", |
6138 | description: r##"As the counterpart to `or_fun_call`, this lint looks for unnecessary\nlazily evaluated closures on `Option` and `Result`.\n\nThis lint suggests changing the following functions, when eager evaluation results in\nsimpler code:\n - `unwrap_or_else` to `unwrap_or`\n - `and_then` to `and`\n - `or_else` to `or`\n - `get_or_insert_with` to `get_or_insert`\n - `ok_or_else` to `ok_or`"##, | 6678 | description: r##"As the counterpart to `or_fun_call`, this lint looks for unnecessary\nlazily evaluated closures on `Option` and `Result`.\n\nThis lint suggests changing the following functions, when eager evaluation results in\nsimpler code:\n - `unwrap_or_else` to `unwrap_or`\n - `and_then` to `and`\n - `or_else` to `or`\n - `get_or_insert_with` to `get_or_insert`\n - `ok_or_else` to `ok_or`"##, |
6139 | }, | 6679 | }, |
6140 | LintCompletion { | 6680 | Lint { |
6141 | label: "clippy::unnecessary_mut_passed", | 6681 | label: "clippy::unnecessary_mut_passed", |
6142 | description: r##"Detects passing a mutable reference to a function that only\nrequires an immutable reference."##, | 6682 | description: r##"Detects passing a mutable reference to a function that only\nrequires an immutable reference."##, |
6143 | }, | 6683 | }, |
6144 | LintCompletion { | 6684 | Lint { |
6145 | label: "clippy::unnecessary_operation", | 6685 | label: "clippy::unnecessary_operation", |
6146 | description: r##"Checks for expression statements that can be reduced to a\nsub-expression."##, | 6686 | description: r##"Checks for expression statements that can be reduced to a\nsub-expression."##, |
6147 | }, | 6687 | }, |
6148 | LintCompletion { | 6688 | Lint { |
6689 | label: "clippy::unnecessary_self_imports", | ||
6690 | description: r##"Checks for imports ending in `::{self}`."##, | ||
6691 | }, | ||
6692 | Lint { | ||
6149 | label: "clippy::unnecessary_sort_by", | 6693 | label: "clippy::unnecessary_sort_by", |
6150 | description: r##"Detects uses of `Vec::sort_by` passing in a closure\nwhich compares the two arguments, either directly or indirectly."##, | 6694 | description: r##"Detects uses of `Vec::sort_by` passing in a closure\nwhich compares the two arguments, either directly or indirectly."##, |
6151 | }, | 6695 | }, |
6152 | LintCompletion { | 6696 | Lint { |
6153 | label: "clippy::unnecessary_unwrap", | 6697 | label: "clippy::unnecessary_unwrap", |
6154 | description: r##"Checks for calls of `unwrap[_err]()` that cannot fail."##, | 6698 | description: r##"Checks for calls of `unwrap[_err]()` that cannot fail."##, |
6155 | }, | 6699 | }, |
6156 | LintCompletion { | 6700 | Lint { |
6157 | label: "clippy::unnecessary_wraps", | 6701 | label: "clippy::unnecessary_wraps", |
6158 | description: r##"Checks for private functions that only return `Ok` or `Some`."##, | 6702 | description: r##"Checks for private functions that only return `Ok` or `Some`."##, |
6159 | }, | 6703 | }, |
6160 | LintCompletion { | 6704 | Lint { |
6161 | label: "clippy::unneeded_field_pattern", | 6705 | label: "clippy::unneeded_field_pattern", |
6162 | description: r##"Checks for structure field patterns bound to wildcards."##, | 6706 | description: r##"Checks for structure field patterns bound to wildcards."##, |
6163 | }, | 6707 | }, |
6164 | LintCompletion { | 6708 | Lint { |
6165 | label: "clippy::unneeded_wildcard_pattern", | 6709 | label: "clippy::unneeded_wildcard_pattern", |
6166 | description: r##"Checks for tuple patterns with a wildcard\npattern (`_`) is next to a rest pattern (`..`).\n\n_NOTE_: While `_, ..` means there is at least one element left, `..`\nmeans there are 0 or more elements left. This can make a difference\nwhen refactoring, but shouldn't result in errors in the refactored code,\nsince the wildcard pattern isn't used anyway."##, | 6710 | description: r##"Checks for tuple patterns with a wildcard\npattern (`_`) is next to a rest pattern (`..`).\n\n_NOTE_: While `_, ..` means there is at least one element left, `..`\nmeans there are 0 or more elements left. This can make a difference\nwhen refactoring, but shouldn't result in errors in the refactored code,\nsince the wildcard pattern isn't used anyway."##, |
6167 | }, | 6711 | }, |
6168 | LintCompletion { | 6712 | Lint { |
6169 | label: "clippy::unnested_or_patterns", | 6713 | label: "clippy::unnested_or_patterns", |
6170 | description: r##"Checks for unnested or-patterns, e.g., `Some(0) | Some(2)` and\nsuggests replacing the pattern with a nested one, `Some(0 | 2)`.\n\nAnother way to think of this is that it rewrites patterns in\n*disjunctive normal form (DNF)* into *conjunctive normal form (CNF)*."##, | 6714 | description: r##"Checks for unnested or-patterns, e.g., `Some(0) | Some(2)` and\nsuggests replacing the pattern with a nested one, `Some(0 | 2)`.\n\nAnother way to think of this is that it rewrites patterns in\n*disjunctive normal form (DNF)* into *conjunctive normal form (CNF)*."##, |
6171 | }, | 6715 | }, |
6172 | LintCompletion { | 6716 | Lint { label: "clippy::unreachable", description: r##"Checks for usage of `unreachable!`."## }, |
6173 | label: "clippy::unreachable", | 6717 | Lint { |
6174 | description: r##"Checks for usage of `unreachable!`."##, | ||
6175 | }, | ||
6176 | LintCompletion { | ||
6177 | label: "clippy::unreadable_literal", | 6718 | label: "clippy::unreadable_literal", |
6178 | description: r##"Warns if a long integral or floating-point constant does\nnot contain underscores."##, | 6719 | description: r##"Warns if a long integral or floating-point constant does\nnot contain underscores."##, |
6179 | }, | 6720 | }, |
6180 | LintCompletion { | 6721 | Lint { |
6181 | label: "clippy::unsafe_derive_deserialize", | 6722 | label: "clippy::unsafe_derive_deserialize", |
6182 | description: r##"Checks for deriving `serde::Deserialize` on a type that\nhas methods using `unsafe`."##, | 6723 | description: r##"Checks for deriving `serde::Deserialize` on a type that\nhas methods using `unsafe`."##, |
6183 | }, | 6724 | }, |
6184 | LintCompletion { | 6725 | Lint { |
6185 | label: "clippy::unsafe_removed_from_name", | 6726 | label: "clippy::unsafe_removed_from_name", |
6186 | description: r##"Checks for imports that remove \"unsafe\" from an item's\nname."##, | 6727 | description: r##"Checks for imports that remove \"unsafe\" from an item's\nname."##, |
6187 | }, | 6728 | }, |
6188 | LintCompletion { | 6729 | Lint { |
6189 | label: "clippy::unsafe_vector_initialization", | 6730 | label: "clippy::unsafe_vector_initialization", |
6190 | description: r##"Nothing. This lint has been deprecated."##, | 6731 | description: r##"Nothing. This lint has been deprecated."##, |
6191 | }, | 6732 | }, |
6192 | LintCompletion { | 6733 | Lint { |
6193 | label: "clippy::unseparated_literal_suffix", | 6734 | label: "clippy::unseparated_literal_suffix", |
6194 | description: r##"Warns if literal suffixes are not separated by an\nunderscore."##, | 6735 | description: r##"Warns if literal suffixes are not separated by an\nunderscore."##, |
6195 | }, | 6736 | }, |
6196 | LintCompletion { | 6737 | Lint { |
6197 | label: "clippy::unsound_collection_transmute", | 6738 | label: "clippy::unsound_collection_transmute", |
6198 | description: r##"Checks for transmutes between collections whose\ntypes have different ABI, size or alignment."##, | 6739 | description: r##"Checks for transmutes between collections whose\ntypes have different ABI, size or alignment."##, |
6199 | }, | 6740 | }, |
6200 | LintCompletion { | 6741 | Lint { |
6201 | label: "clippy::unstable_as_mut_slice", | 6742 | label: "clippy::unstable_as_mut_slice", |
6202 | description: r##"Nothing. This lint has been deprecated."##, | 6743 | description: r##"Nothing. This lint has been deprecated."##, |
6203 | }, | 6744 | }, |
6204 | LintCompletion { | 6745 | Lint { |
6205 | label: "clippy::unstable_as_slice", | 6746 | label: "clippy::unstable_as_slice", |
6206 | description: r##"Nothing. This lint has been deprecated."##, | 6747 | description: r##"Nothing. This lint has been deprecated."##, |
6207 | }, | 6748 | }, |
6208 | LintCompletion { | 6749 | Lint { |
6750 | label: "clippy::unused_async", | ||
6751 | description: r##"Checks for functions that are declared `async` but have no `.await`s inside of them."##, | ||
6752 | }, | ||
6753 | Lint { | ||
6209 | label: "clippy::unused_collect", | 6754 | label: "clippy::unused_collect", |
6210 | description: r##"Nothing. This lint has been deprecated."##, | 6755 | description: r##"Nothing. This lint has been deprecated."##, |
6211 | }, | 6756 | }, |
6212 | LintCompletion { | 6757 | Lint { |
6213 | label: "clippy::unused_io_amount", | 6758 | label: "clippy::unused_io_amount", |
6214 | description: r##"Checks for unused written/read amount."##, | 6759 | description: r##"Checks for unused written/read amount."##, |
6215 | }, | 6760 | }, |
6216 | LintCompletion { | 6761 | Lint { |
6217 | label: "clippy::unused_label", | ||
6218 | description: r##"Nothing. This lint has been deprecated."##, | ||
6219 | }, | ||
6220 | LintCompletion { | ||
6221 | label: "clippy::unused_self", | 6762 | label: "clippy::unused_self", |
6222 | description: r##"Checks methods that contain a `self` argument but don't use it"##, | 6763 | description: r##"Checks methods that contain a `self` argument but don't use it"##, |
6223 | }, | 6764 | }, |
6224 | LintCompletion { | 6765 | Lint { |
6225 | label: "clippy::unused_unit", | 6766 | label: "clippy::unused_unit", |
6226 | description: r##"Checks for unit (`()`) expressions that can be removed."##, | 6767 | description: r##"Checks for unit (`()`) expressions that can be removed."##, |
6227 | }, | 6768 | }, |
6228 | LintCompletion { | 6769 | Lint { |
6229 | label: "clippy::unusual_byte_groupings", | 6770 | label: "clippy::unusual_byte_groupings", |
6230 | description: r##"Warns if hexadecimal or binary literals are not grouped\nby nibble or byte."##, | 6771 | description: r##"Warns if hexadecimal or binary literals are not grouped\nby nibble or byte."##, |
6231 | }, | 6772 | }, |
6232 | LintCompletion { | 6773 | Lint { |
6233 | label: "clippy::unwrap_in_result", | 6774 | label: "clippy::unwrap_in_result", |
6234 | description: r##"Checks for functions of type Result that contain `expect()` or `unwrap()`"##, | 6775 | description: r##"Checks for functions of type Result that contain `expect()` or `unwrap()`"##, |
6235 | }, | 6776 | }, |
6236 | LintCompletion { | 6777 | Lint { |
6237 | label: "clippy::unwrap_used", | 6778 | label: "clippy::unwrap_used", |
6238 | description: r##"Checks for `.unwrap()` calls on `Option`s and on `Result`s."##, | 6779 | description: r##"Checks for `.unwrap()` calls on `Option`s and on `Result`s."##, |
6239 | }, | 6780 | }, |
6240 | LintCompletion { | 6781 | Lint { |
6241 | label: "clippy::upper_case_acronyms", | 6782 | label: "clippy::upper_case_acronyms", |
6242 | description: r##"Checks for fully capitalized names and optionally names containing a capitalized acronym."##, | 6783 | description: r##"Checks for fully capitalized names and optionally names containing a capitalized acronym."##, |
6243 | }, | 6784 | }, |
6244 | LintCompletion { | 6785 | Lint { |
6245 | label: "clippy::use_debug", | 6786 | label: "clippy::use_debug", |
6246 | description: r##"Checks for use of `Debug` formatting. The purpose of this\nlint is to catch debugging remnants."##, | 6787 | description: r##"Checks for use of `Debug` formatting. The purpose of this\nlint is to catch debugging remnants."##, |
6247 | }, | 6788 | }, |
6248 | LintCompletion { | 6789 | Lint { |
6249 | label: "clippy::use_self", | 6790 | label: "clippy::use_self", |
6250 | description: r##"Checks for unnecessary repetition of structure name when a\nreplacement with `Self` is applicable."##, | 6791 | description: r##"Checks for unnecessary repetition of structure name when a\nreplacement with `Self` is applicable."##, |
6251 | }, | 6792 | }, |
6252 | LintCompletion { | 6793 | Lint { |
6253 | label: "clippy::used_underscore_binding", | 6794 | label: "clippy::used_underscore_binding", |
6254 | description: r##"Checks for the use of bindings with a single leading\nunderscore."##, | 6795 | description: r##"Checks for the use of bindings with a single leading\nunderscore."##, |
6255 | }, | 6796 | }, |
6256 | LintCompletion { | 6797 | Lint { |
6257 | label: "clippy::useless_asref", | 6798 | label: "clippy::useless_asref", |
6258 | description: r##"Checks for usage of `.as_ref()` or `.as_mut()` where the\ntypes before and after the call are the same."##, | 6799 | description: r##"Checks for usage of `.as_ref()` or `.as_mut()` where the\ntypes before and after the call are the same."##, |
6259 | }, | 6800 | }, |
6260 | LintCompletion { | 6801 | Lint { |
6261 | label: "clippy::useless_attribute", | 6802 | label: "clippy::useless_attribute", |
6262 | description: r##"Checks for `extern crate` and `use` items annotated with\nlint attributes.\n\nThis lint permits `#[allow(unused_imports)]`, `#[allow(deprecated)]`,\n`#[allow(unreachable_pub)]`, `#[allow(clippy::wildcard_imports)]` and\n`#[allow(clippy::enum_glob_use)]` on `use` items and `#[allow(unused_imports)]` on\n`extern crate` items with a `#[macro_use]` attribute."##, | 6803 | description: r##"Checks for `extern crate` and `use` items annotated with\nlint attributes.\n\nThis lint permits `#[allow(unused_imports)]`, `#[allow(deprecated)]`,\n`#[allow(unreachable_pub)]`, `#[allow(clippy::wildcard_imports)]` and\n`#[allow(clippy::enum_glob_use)]` on `use` items and `#[allow(unused_imports)]` on\n`extern crate` items with a `#[macro_use]` attribute."##, |
6263 | }, | 6804 | }, |
6264 | LintCompletion { | 6805 | Lint { |
6265 | label: "clippy::useless_conversion", | 6806 | label: "clippy::useless_conversion", |
6266 | description: r##"Checks for `Into`, `TryInto`, `From`, `TryFrom`, or `IntoIter` calls\nwhich uselessly convert to the same type."##, | 6807 | description: r##"Checks for `Into`, `TryInto`, `From`, `TryFrom`, or `IntoIter` calls\nwhich uselessly convert to the same type."##, |
6267 | }, | 6808 | }, |
6268 | LintCompletion { | 6809 | Lint { |
6269 | label: "clippy::useless_format", | 6810 | label: "clippy::useless_format", |
6270 | description: r##"Checks for the use of `format!(\"string literal with no\nargument\")` and `format!(\"{}\", foo)` where `foo` is a string."##, | 6811 | description: r##"Checks for the use of `format!(\"string literal with no\nargument\")` and `format!(\"{}\", foo)` where `foo` is a string."##, |
6271 | }, | 6812 | }, |
6272 | LintCompletion { | 6813 | Lint { |
6273 | label: "clippy::useless_let_if_seq", | 6814 | label: "clippy::useless_let_if_seq", |
6274 | description: r##"Checks for variable declarations immediately followed by a\nconditional affectation."##, | 6815 | description: r##"Checks for variable declarations immediately followed by a\nconditional affectation."##, |
6275 | }, | 6816 | }, |
6276 | LintCompletion { | 6817 | Lint { |
6277 | label: "clippy::useless_transmute", | 6818 | label: "clippy::useless_transmute", |
6278 | description: r##"Checks for transmutes to the original type of the object\nand transmutes that could be a cast."##, | 6819 | description: r##"Checks for transmutes to the original type of the object\nand transmutes that could be a cast."##, |
6279 | }, | 6820 | }, |
6280 | LintCompletion { | 6821 | Lint { |
6281 | label: "clippy::useless_vec", | 6822 | label: "clippy::useless_vec", |
6282 | description: r##"Checks for usage of `&vec![..]` when using `&[..]` would\nbe possible."##, | 6823 | description: r##"Checks for usage of `&vec![..]` when using `&[..]` would\nbe possible."##, |
6283 | }, | 6824 | }, |
6284 | LintCompletion { | 6825 | Lint { |
6285 | label: "clippy::vec_box", | 6826 | label: "clippy::vec_box", |
6286 | description: r##"Checks for use of `Vec<Box<T>>` where T: Sized anywhere in the code.\nCheck the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information."##, | 6827 | description: r##"Checks for use of `Vec<Box<T>>` where T: Sized anywhere in the code.\nCheck the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information."##, |
6287 | }, | 6828 | }, |
6288 | LintCompletion { | 6829 | Lint { |
6289 | label: "clippy::vec_init_then_push", | 6830 | label: "clippy::vec_init_then_push", |
6290 | description: r##"Checks for calls to `push` immediately after creating a new `Vec`."##, | 6831 | description: r##"Checks for calls to `push` immediately after creating a new `Vec`."##, |
6291 | }, | 6832 | }, |
6292 | LintCompletion { | 6833 | Lint { |
6293 | label: "clippy::vec_resize_to_zero", | 6834 | label: "clippy::vec_resize_to_zero", |
6294 | description: r##"Finds occurrences of `Vec::resize(0, an_int)`"##, | 6835 | description: r##"Finds occurrences of `Vec::resize(0, an_int)`"##, |
6295 | }, | 6836 | }, |
6296 | LintCompletion { | 6837 | Lint { |
6297 | label: "clippy::verbose_bit_mask", | 6838 | label: "clippy::verbose_bit_mask", |
6298 | description: r##"Checks for bit masks that can be replaced by a call\nto `trailing_zeros`"##, | 6839 | description: r##"Checks for bit masks that can be replaced by a call\nto `trailing_zeros`"##, |
6299 | }, | 6840 | }, |
6300 | LintCompletion { | 6841 | Lint { |
6301 | label: "clippy::verbose_file_reads", | 6842 | label: "clippy::verbose_file_reads", |
6302 | description: r##"Checks for use of File::read_to_end and File::read_to_string."##, | 6843 | description: r##"Checks for use of File::read_to_end and File::read_to_string."##, |
6303 | }, | 6844 | }, |
6304 | LintCompletion { | 6845 | Lint { |
6305 | label: "clippy::vtable_address_comparisons", | 6846 | label: "clippy::vtable_address_comparisons", |
6306 | description: r##"Checks for comparisons with an address of a trait vtable."##, | 6847 | description: r##"Checks for comparisons with an address of a trait vtable."##, |
6307 | }, | 6848 | }, |
6308 | LintCompletion { | 6849 | Lint { |
6309 | label: "clippy::while_immutable_condition", | 6850 | label: "clippy::while_immutable_condition", |
6310 | description: r##"Checks whether variables used within while loop condition\ncan be (and are) mutated in the body."##, | 6851 | description: r##"Checks whether variables used within while loop condition\ncan be (and are) mutated in the body."##, |
6311 | }, | 6852 | }, |
6312 | LintCompletion { | 6853 | Lint { |
6313 | label: "clippy::while_let_loop", | 6854 | label: "clippy::while_let_loop", |
6314 | description: r##"Detects `loop + match` combinations that are easier\nwritten as a `while let` loop."##, | 6855 | description: r##"Detects `loop + match` combinations that are easier\nwritten as a `while let` loop."##, |
6315 | }, | 6856 | }, |
6316 | LintCompletion { | 6857 | Lint { |
6317 | label: "clippy::while_let_on_iterator", | 6858 | label: "clippy::while_let_on_iterator", |
6318 | description: r##"Checks for `while let` expressions on iterators."##, | 6859 | description: r##"Checks for `while let` expressions on iterators."##, |
6319 | }, | 6860 | }, |
6320 | LintCompletion { | 6861 | Lint { |
6321 | label: "clippy::wildcard_dependencies", | 6862 | label: "clippy::wildcard_dependencies", |
6322 | description: r##"Checks for wildcard dependencies in the `Cargo.toml`."##, | 6863 | description: r##"Checks for wildcard dependencies in the `Cargo.toml`."##, |
6323 | }, | 6864 | }, |
6324 | LintCompletion { | 6865 | Lint { |
6325 | label: "clippy::wildcard_enum_match_arm", | 6866 | label: "clippy::wildcard_enum_match_arm", |
6326 | description: r##"Checks for wildcard enum matches using `_`."##, | 6867 | description: r##"Checks for wildcard enum matches using `_`."##, |
6327 | }, | 6868 | }, |
6328 | LintCompletion { | 6869 | Lint { |
6329 | label: "clippy::wildcard_imports", | 6870 | label: "clippy::wildcard_imports", |
6330 | description: r##"Checks for wildcard imports `use _::*`."##, | 6871 | description: r##"Checks for wildcard imports `use _::*`."##, |
6331 | }, | 6872 | }, |
6332 | LintCompletion { | 6873 | Lint { |
6333 | label: "clippy::wildcard_in_or_patterns", | 6874 | label: "clippy::wildcard_in_or_patterns", |
6334 | description: r##"Checks for wildcard pattern used with others patterns in same match arm."##, | 6875 | description: r##"Checks for wildcard pattern used with others patterns in same match arm."##, |
6335 | }, | 6876 | }, |
6336 | LintCompletion { | 6877 | Lint { |
6337 | label: "clippy::write_literal", | 6878 | label: "clippy::write_literal", |
6338 | description: r##"This lint warns about the use of literals as `write!`/`writeln!` args."##, | 6879 | description: r##"This lint warns about the use of literals as `write!`/`writeln!` args."##, |
6339 | }, | 6880 | }, |
6340 | LintCompletion { | 6881 | Lint { |
6341 | label: "clippy::write_with_newline", | 6882 | label: "clippy::write_with_newline", |
6342 | description: r##"This lint warns when you use `write!()` with a format\nstring that\nends in a newline."##, | 6883 | description: r##"This lint warns when you use `write!()` with a format\nstring that\nends in a newline."##, |
6343 | }, | 6884 | }, |
6344 | LintCompletion { | 6885 | Lint { |
6345 | label: "clippy::writeln_empty_string", | 6886 | label: "clippy::writeln_empty_string", |
6346 | description: r##"This lint warns when you use `writeln!(buf, \"\")` to\nprint a newline."##, | 6887 | description: r##"This lint warns when you use `writeln!(buf, \"\")` to\nprint a newline."##, |
6347 | }, | 6888 | }, |
6348 | LintCompletion { | 6889 | Lint { |
6349 | label: "clippy::wrong_pub_self_convention", | 6890 | label: "clippy::wrong_pub_self_convention", |
6350 | description: r##"This is the same as\n[`wrong_self_convention`](#wrong_self_convention), but for public items."##, | 6891 | description: r##"Nothing. This lint has been deprecated."##, |
6351 | }, | 6892 | }, |
6352 | LintCompletion { | 6893 | Lint { |
6353 | label: "clippy::wrong_self_convention", | 6894 | label: "clippy::wrong_self_convention", |
6354 | description: r##"Checks for methods with certain name prefixes and which\ndoesn't match how self is taken. The actual rules are:\n\n|Prefix |`self` taken |\n|-------|----------------------|\n|`as_` |`&self` or `&mut self`|\n|`from_`| none |\n|`into_`|`self` |\n|`is_` |`&self` or none |\n|`to_` |`&self` |"##, | 6895 | description: r##"Checks for methods with certain name prefixes and which\ndoesn't match how self is taken. The actual rules are:\n\n|Prefix |Postfix |`self` taken | `self` type |\n|-------|------------|-----------------------|--------------|\n|`as_` | none |`&self` or `&mut self` | any |\n|`from_`| none | none | any |\n|`into_`| none |`self` | any |\n|`is_` | none |`&self` or none | any |\n|`to_` | `_mut` |`&mut self` | any |\n|`to_` | not `_mut` |`self` | `Copy` |\n|`to_` | not `_mut` |`&self` | not `Copy` |\n\nNote: Clippy doesn't trigger methods with `to_` prefix in:\n- Traits definition.\nClippy can not tell if a type that implements a trait is `Copy` or not.\n- Traits implementation, when `&self` is taken.\nThe method signature is controlled by the trait and often `&self` is required for all types that implement the trait\n(see e.g. the `std::string::ToString` trait).\n\nPlease find more info here:\nhttps://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv"##, |
6355 | }, | 6896 | }, |
6356 | LintCompletion { | 6897 | Lint { |
6357 | label: "clippy::wrong_transmute", | 6898 | label: "clippy::wrong_transmute", |
6358 | description: r##"Checks for transmutes that can't ever be correct on any\narchitecture."##, | 6899 | description: r##"Checks for transmutes that can't ever be correct on any\narchitecture."##, |
6359 | }, | 6900 | }, |
6360 | LintCompletion { | 6901 | Lint { label: "clippy::zero_divided_by_zero", description: r##"Checks for `0.0 / 0.0`."## }, |
6361 | label: "clippy::zero_divided_by_zero", | 6902 | Lint { |
6362 | description: r##"Checks for `0.0 / 0.0`."##, | ||
6363 | }, | ||
6364 | LintCompletion { | ||
6365 | label: "clippy::zero_prefixed_literal", | 6903 | label: "clippy::zero_prefixed_literal", |
6366 | description: r##"Warns if an integral constant literal starts with `0`."##, | 6904 | description: r##"Warns if an integral constant literal starts with `0`."##, |
6367 | }, | 6905 | }, |
6368 | LintCompletion { | 6906 | Lint { |
6369 | label: "clippy::zero_ptr", | 6907 | label: "clippy::zero_ptr", |
6370 | description: r##"Catch casts from `0` to some pointer type"##, | 6908 | description: r##"Catch casts from `0` to some pointer type"##, |
6371 | }, | 6909 | }, |
6372 | LintCompletion { | 6910 | Lint { |
6373 | label: "clippy::zero_sized_map_values", | 6911 | label: "clippy::zero_sized_map_values", |
6374 | description: r##"Checks for maps with zero-sized value types anywhere in the code."##, | 6912 | description: r##"Checks for maps with zero-sized value types anywhere in the code."##, |
6375 | }, | 6913 | }, |
6376 | LintCompletion { | 6914 | Lint { |
6377 | label: "clippy::zst_offset", | 6915 | label: "clippy::zst_offset", |
6378 | description: r##"Checks for `offset(_)`, `wrapping_`{`add`, `sub`}, etc. on raw pointers to\nzero-sized types"##, | 6916 | description: r##"Checks for `offset(_)`, `wrapping_`{`add`, `sub`}, etc. on raw pointers to\nzero-sized types"##, |
6379 | }, | 6917 | }, |