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f20569fa | 1 | //! Clippy wrappers around rustc's diagnostic functions. |
17df50a5 XL |
2 | //! |
3 | //! These functions are used by the `INTERNAL_METADATA_COLLECTOR` lint to collect the corresponding | |
4 | //! lint applicability. Please make sure that you update the `LINT_EMISSION_FUNCTIONS` variable in | |
5 | //! `clippy_lints::utils::internal_lints::metadata_collector` when a new function is added | |
6 | //! or renamed. | |
7 | //! | |
8 | //! Thank you! | |
9 | //! ~The `INTERNAL_METADATA_COLLECTOR` lint | |
f20569fa | 10 | |
064997fb | 11 | use rustc_errors::{Applicability, Diagnostic, MultiSpan}; |
f20569fa XL |
12 | use rustc_hir::HirId; |
13 | use rustc_lint::{LateContext, Lint, LintContext}; | |
04454e1e | 14 | use rustc_span::source_map::Span; |
f20569fa XL |
15 | use std::env; |
16 | ||
5e7ed085 | 17 | fn docs_link(diag: &mut Diagnostic, lint: &'static Lint) { |
f20569fa | 18 | if env::var("CLIPPY_DISABLE_DOCS_LINKS").is_err() { |
cdc7bbd5 XL |
19 | if let Some(lint) = lint.name_lower().strip_prefix("clippy::") { |
20 | diag.help(&format!( | |
21 | "for further information visit https://rust-lang.github.io/rust-clippy/{}/index.html#{}", | |
22 | &option_env!("RUST_RELEASE_NUM").map_or("master".to_string(), |n| { | |
23 | // extract just major + minor version and ignore patch versions | |
c295e0f8 | 24 | format!("rust-{}", n.rsplit_once('.').unwrap().1) |
cdc7bbd5 XL |
25 | }), |
26 | lint | |
27 | )); | |
28 | } | |
f20569fa XL |
29 | } |
30 | } | |
31 | ||
32 | /// Emit a basic lint message with a `msg` and a `span`. | |
33 | /// | |
34 | /// This is the most primitive of our lint emission methods and can | |
35 | /// be a good way to get a new lint started. | |
36 | /// | |
37 | /// Usually it's nicer to provide more context for lint messages. | |
38 | /// Be sure the output is understandable when you use this method. | |
39 | /// | |
40 | /// # Example | |
41 | /// | |
42 | /// ```ignore | |
43 | /// error: usage of mem::forget on Drop type | |
44 | /// --> $DIR/mem_forget.rs:17:5 | |
45 | /// | | |
46 | /// 17 | std::mem::forget(seven); | |
47 | /// | ^^^^^^^^^^^^^^^^^^^^^^^ | |
48 | /// ``` | |
49 | pub fn span_lint<T: LintContext>(cx: &T, lint: &'static Lint, sp: impl Into<MultiSpan>, msg: &str) { | |
50 | cx.struct_span_lint(lint, sp, |diag| { | |
51 | let mut diag = diag.build(msg); | |
52 | docs_link(&mut diag, lint); | |
53 | diag.emit(); | |
54 | }); | |
55 | } | |
56 | ||
57 | /// Same as `span_lint` but with an extra `help` message. | |
58 | /// | |
59 | /// Use this if you want to provide some general help but | |
60 | /// can't provide a specific machine applicable suggestion. | |
61 | /// | |
62 | /// The `help` message can be optionally attached to a `Span`. | |
63 | /// | |
64 | /// If you change the signature, remember to update the internal lint `CollapsibleCalls` | |
65 | /// | |
66 | /// # Example | |
67 | /// | |
94222f64 | 68 | /// ```text |
f20569fa XL |
69 | /// error: constant division of 0.0 with 0.0 will always result in NaN |
70 | /// --> $DIR/zero_div_zero.rs:6:25 | |
71 | /// | | |
72 | /// 6 | let other_f64_nan = 0.0f64 / 0.0; | |
73 | /// | ^^^^^^^^^^^^ | |
74 | /// | | |
3c0e092e | 75 | /// = help: consider using `f64::NAN` if you would like a constant representing NaN |
f20569fa XL |
76 | /// ``` |
77 | pub fn span_lint_and_help<'a, T: LintContext>( | |
78 | cx: &'a T, | |
79 | lint: &'static Lint, | |
923072b8 | 80 | span: impl Into<MultiSpan>, |
f20569fa XL |
81 | msg: &str, |
82 | help_span: Option<Span>, | |
83 | help: &str, | |
84 | ) { | |
85 | cx.struct_span_lint(lint, span, |diag| { | |
86 | let mut diag = diag.build(msg); | |
87 | if let Some(help_span) = help_span { | |
88 | diag.span_help(help_span, help); | |
89 | } else { | |
90 | diag.help(help); | |
91 | } | |
92 | docs_link(&mut diag, lint); | |
93 | diag.emit(); | |
94 | }); | |
95 | } | |
96 | ||
97 | /// Like `span_lint` but with a `note` section instead of a `help` message. | |
98 | /// | |
99 | /// The `note` message is presented separately from the main lint message | |
100 | /// and is attached to a specific span: | |
101 | /// | |
102 | /// If you change the signature, remember to update the internal lint `CollapsibleCalls` | |
103 | /// | |
104 | /// # Example | |
105 | /// | |
94222f64 | 106 | /// ```text |
f20569fa XL |
107 | /// error: calls to `std::mem::forget` with a reference instead of an owned value. Forgetting a reference does nothing. |
108 | /// --> $DIR/drop_forget_ref.rs:10:5 | |
109 | /// | | |
110 | /// 10 | forget(&SomeStruct); | |
111 | /// | ^^^^^^^^^^^^^^^^^^^ | |
112 | /// | | |
113 | /// = note: `-D clippy::forget-ref` implied by `-D warnings` | |
114 | /// note: argument has type &SomeStruct | |
115 | /// --> $DIR/drop_forget_ref.rs:10:12 | |
116 | /// | | |
117 | /// 10 | forget(&SomeStruct); | |
118 | /// | ^^^^^^^^^^^ | |
119 | /// ``` | |
120 | pub fn span_lint_and_note<'a, T: LintContext>( | |
121 | cx: &'a T, | |
122 | lint: &'static Lint, | |
123 | span: impl Into<MultiSpan>, | |
124 | msg: &str, | |
125 | note_span: Option<Span>, | |
126 | note: &str, | |
127 | ) { | |
128 | cx.struct_span_lint(lint, span, |diag| { | |
129 | let mut diag = diag.build(msg); | |
130 | if let Some(note_span) = note_span { | |
131 | diag.span_note(note_span, note); | |
132 | } else { | |
133 | diag.note(note); | |
134 | } | |
135 | docs_link(&mut diag, lint); | |
136 | diag.emit(); | |
137 | }); | |
138 | } | |
139 | ||
140 | /// Like `span_lint` but allows to add notes, help and suggestions using a closure. | |
141 | /// | |
142 | /// If you need to customize your lint output a lot, use this function. | |
143 | /// If you change the signature, remember to update the internal lint `CollapsibleCalls` | |
cdc7bbd5 | 144 | pub fn span_lint_and_then<C, S, F>(cx: &C, lint: &'static Lint, sp: S, msg: &str, f: F) |
f20569fa | 145 | where |
cdc7bbd5 XL |
146 | C: LintContext, |
147 | S: Into<MultiSpan>, | |
5e7ed085 | 148 | F: FnOnce(&mut Diagnostic), |
f20569fa XL |
149 | { |
150 | cx.struct_span_lint(lint, sp, |diag| { | |
151 | let mut diag = diag.build(msg); | |
152 | f(&mut diag); | |
153 | docs_link(&mut diag, lint); | |
154 | diag.emit(); | |
155 | }); | |
156 | } | |
157 | ||
04454e1e FG |
158 | pub fn span_lint_hir( |
159 | cx: &LateContext<'_>, | |
160 | lint: &'static Lint, | |
161 | hir_id: HirId, | |
162 | sp: Span, | |
163 | msg: &str, | |
164 | ) { | |
f20569fa XL |
165 | cx.tcx.struct_span_lint_hir(lint, hir_id, sp, |diag| { |
166 | let mut diag = diag.build(msg); | |
167 | docs_link(&mut diag, lint); | |
168 | diag.emit(); | |
169 | }); | |
170 | } | |
171 | ||
172 | pub fn span_lint_hir_and_then( | |
173 | cx: &LateContext<'_>, | |
174 | lint: &'static Lint, | |
175 | hir_id: HirId, | |
17df50a5 | 176 | sp: impl Into<MultiSpan>, |
f20569fa | 177 | msg: &str, |
5e7ed085 | 178 | f: impl FnOnce(&mut Diagnostic), |
f20569fa XL |
179 | ) { |
180 | cx.tcx.struct_span_lint_hir(lint, hir_id, sp, |diag| { | |
181 | let mut diag = diag.build(msg); | |
182 | f(&mut diag); | |
183 | docs_link(&mut diag, lint); | |
184 | diag.emit(); | |
185 | }); | |
186 | } | |
187 | ||
188 | /// Add a span lint with a suggestion on how to fix it. | |
189 | /// | |
190 | /// These suggestions can be parsed by rustfix to allow it to automatically fix your code. | |
191 | /// In the example below, `help` is `"try"` and `sugg` is the suggested replacement `".any(|x| x > | |
192 | /// 2)"`. | |
193 | /// | |
194 | /// If you change the signature, remember to update the internal lint `CollapsibleCalls` | |
195 | /// | |
196 | /// # Example | |
197 | /// | |
94222f64 | 198 | /// ```text |
f20569fa XL |
199 | /// error: This `.fold` can be more succinctly expressed as `.any` |
200 | /// --> $DIR/methods.rs:390:13 | |
201 | /// | | |
202 | /// 390 | let _ = (0..3).fold(false, |acc, x| acc || x > 2); | |
203 | /// | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `.any(|x| x > 2)` | |
204 | /// | | |
205 | /// = note: `-D fold-any` implied by `-D warnings` | |
206 | /// ``` | |
5099ac24 | 207 | #[cfg_attr(feature = "internal", allow(clippy::collapsible_span_lint_calls))] |
f20569fa XL |
208 | pub fn span_lint_and_sugg<'a, T: LintContext>( |
209 | cx: &'a T, | |
210 | lint: &'static Lint, | |
211 | sp: Span, | |
212 | msg: &str, | |
213 | help: &str, | |
214 | sugg: String, | |
215 | applicability: Applicability, | |
216 | ) { | |
217 | span_lint_and_then(cx, lint, sp, msg, |diag| { | |
218 | diag.span_suggestion(sp, help, sugg, applicability); | |
219 | }); | |
220 | } | |
221 | ||
222 | /// Create a suggestion made from several `span → replacement`. | |
223 | /// | |
224 | /// Note: in the JSON format (used by `compiletest_rs`), the help message will | |
225 | /// appear once per | |
226 | /// replacement. In human-readable format though, it only appears once before | |
227 | /// the whole suggestion. | |
5e7ed085 | 228 | pub fn multispan_sugg<I>(diag: &mut Diagnostic, help_msg: &str, sugg: I) |
f20569fa XL |
229 | where |
230 | I: IntoIterator<Item = (Span, String)>, | |
231 | { | |
17df50a5 | 232 | multispan_sugg_with_applicability(diag, help_msg, Applicability::Unspecified, sugg); |
f20569fa XL |
233 | } |
234 | ||
cdc7bbd5 XL |
235 | /// Create a suggestion made from several `span → replacement`. |
236 | /// | |
237 | /// rustfix currently doesn't support the automatic application of suggestions with | |
238 | /// multiple spans. This is tracked in issue [rustfix#141](https://github.com/rust-lang/rustfix/issues/141). | |
239 | /// Suggestions with multiple spans will be silently ignored. | |
f20569fa | 240 | pub fn multispan_sugg_with_applicability<I>( |
5e7ed085 | 241 | diag: &mut Diagnostic, |
f20569fa XL |
242 | help_msg: &str, |
243 | applicability: Applicability, | |
244 | sugg: I, | |
245 | ) where | |
246 | I: IntoIterator<Item = (Span, String)>, | |
247 | { | |
248 | diag.multipart_suggestion(help_msg, sugg.into_iter().collect(), applicability); | |
249 | } |