]>
Commit | Line | Data |
---|---|---|
532ac7d7 XL |
1 | //! Some lints that are only useful in the compiler or crates that use compiler internals, such as |
2 | //! Clippy. | |
3 | ||
dfeec247 | 4 | use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext}; |
136023e0 | 5 | use rustc_ast as ast; |
dfeec247 | 6 | use rustc_errors::Applicability; |
1b1a35ee | 7 | use rustc_hir::def::Res; |
136023e0 XL |
8 | use rustc_hir::{ |
9 | GenericArg, HirId, Item, ItemKind, MutTy, Mutability, Node, Path, PathSegment, QPath, Ty, | |
10 | TyKind, | |
11 | }; | |
1b1a35ee | 12 | use rustc_middle::ty; |
136023e0 | 13 | use rustc_session::{declare_lint_pass, declare_tool_lint}; |
dfeec247 | 14 | use rustc_span::hygiene::{ExpnKind, MacroKind}; |
136023e0 | 15 | use rustc_span::symbol::{kw, sym, Symbol}; |
532ac7d7 | 16 | |
416331ca XL |
17 | declare_tool_lint! { |
18 | pub rustc::DEFAULT_HASH_TYPES, | |
532ac7d7 | 19 | Allow, |
dfeec247 XL |
20 | "forbid HashMap and HashSet and suggest the FxHash* variants", |
21 | report_in_external_macro: true | |
532ac7d7 XL |
22 | } |
23 | ||
136023e0 XL |
24 | declare_lint_pass!(DefaultHashTypes => [DEFAULT_HASH_TYPES]); |
25 | ||
26 | impl LateLintPass<'_> for DefaultHashTypes { | |
27 | fn check_path(&mut self, cx: &LateContext<'_>, path: &Path<'_>, hir_id: HirId) { | |
28 | let def_id = match path.res { | |
29 | Res::Def(rustc_hir::def::DefKind::Struct, id) => id, | |
30 | _ => return, | |
31 | }; | |
32 | if matches!(cx.tcx.hir().get(hir_id), Node::Item(Item { kind: ItemKind::Use(..), .. })) { | |
33 | // don't lint imports, only actual usages | |
34 | return; | |
532ac7d7 | 35 | } |
136023e0 XL |
36 | let replace = if cx.tcx.is_diagnostic_item(sym::hashmap_type, def_id) { |
37 | "FxHashMap" | |
38 | } else if cx.tcx.is_diagnostic_item(sym::hashset_type, def_id) { | |
39 | "FxHashSet" | |
40 | } else { | |
41 | return; | |
42 | }; | |
43 | cx.struct_span_lint(DEFAULT_HASH_TYPES, path.span, |lint| { | |
44 | let msg = format!( | |
45 | "prefer `{}` over `{}`, it has better performance", | |
46 | replace, | |
47 | cx.tcx.item_name(def_id) | |
48 | ); | |
49 | lint.build(&msg) | |
50 | .note(&format!("a `use rustc_data_structures::fx::{}` may be necessary", replace)) | |
51 | .emit(); | |
52 | }); | |
532ac7d7 XL |
53 | } |
54 | } | |
55 | ||
416331ca XL |
56 | declare_tool_lint! { |
57 | pub rustc::USAGE_OF_TY_TYKIND, | |
532ac7d7 | 58 | Allow, |
dfeec247 XL |
59 | "usage of `ty::TyKind` outside of the `ty::sty` module", |
60 | report_in_external_macro: true | |
532ac7d7 XL |
61 | } |
62 | ||
416331ca XL |
63 | declare_tool_lint! { |
64 | pub rustc::TY_PASS_BY_REFERENCE, | |
48663c56 | 65 | Allow, |
dfeec247 XL |
66 | "passing `Ty` or `TyCtxt` by reference", |
67 | report_in_external_macro: true | |
48663c56 XL |
68 | } |
69 | ||
416331ca XL |
70 | declare_tool_lint! { |
71 | pub rustc::USAGE_OF_QUALIFIED_TY, | |
48663c56 | 72 | Allow, |
dfeec247 XL |
73 | "using `ty::{Ty,TyCtxt}` instead of importing it", |
74 | report_in_external_macro: true | |
48663c56 XL |
75 | } |
76 | ||
77 | declare_lint_pass!(TyTyKind => [ | |
78 | USAGE_OF_TY_TYKIND, | |
79 | TY_PASS_BY_REFERENCE, | |
80 | USAGE_OF_QUALIFIED_TY, | |
81 | ]); | |
532ac7d7 | 82 | |
f035d41b XL |
83 | impl<'tcx> LateLintPass<'tcx> for TyTyKind { |
84 | fn check_path(&mut self, cx: &LateContext<'_>, path: &'tcx Path<'tcx>, _: HirId) { | |
532ac7d7 XL |
85 | let segments = path.segments.iter().rev().skip(1).rev(); |
86 | ||
87 | if let Some(last) = segments.last() { | |
88 | let span = path.span.with_hi(last.ident.span.hi()); | |
89 | if lint_ty_kind_usage(cx, last) { | |
74b04a01 XL |
90 | cx.struct_span_lint(USAGE_OF_TY_TYKIND, span, |lint| { |
91 | lint.build("usage of `ty::TyKind::<kind>`") | |
92 | .span_suggestion( | |
93 | span, | |
94 | "try using ty::<kind> directly", | |
95 | "ty".to_string(), | |
96 | Applicability::MaybeIncorrect, // ty maybe needs an import | |
97 | ) | |
98 | .emit(); | |
99 | }) | |
532ac7d7 XL |
100 | } |
101 | } | |
102 | } | |
103 | ||
f035d41b | 104 | fn check_ty(&mut self, cx: &LateContext<'_>, ty: &'tcx Ty<'tcx>) { |
e74abb32 | 105 | match &ty.kind { |
48663c56 XL |
106 | TyKind::Path(qpath) => { |
107 | if let QPath::Resolved(_, path) = qpath { | |
108 | if let Some(last) = path.segments.iter().last() { | |
109 | if lint_ty_kind_usage(cx, last) { | |
74b04a01 XL |
110 | cx.struct_span_lint(USAGE_OF_TY_TYKIND, path.span, |lint| { |
111 | lint.build("usage of `ty::TyKind`") | |
112 | .help("try using `Ty` instead") | |
113 | .emit(); | |
114 | }) | |
48663c56 | 115 | } else { |
e1599b0c | 116 | if ty.span.from_expansion() { |
48663c56 XL |
117 | return; |
118 | } | |
119 | if let Some(t) = is_ty_or_ty_ctxt(cx, ty) { | |
120 | if path.segments.len() > 1 { | |
74b04a01 XL |
121 | cx.struct_span_lint(USAGE_OF_QUALIFIED_TY, path.span, |lint| { |
122 | lint.build(&format!("usage of qualified `ty::{}`", t)) | |
123 | .span_suggestion( | |
124 | path.span, | |
125 | "try using it unqualified", | |
126 | t, | |
127 | // The import probably needs to be changed | |
128 | Applicability::MaybeIncorrect, | |
129 | ) | |
130 | .emit(); | |
131 | }) | |
48663c56 XL |
132 | } |
133 | } | |
134 | } | |
135 | } | |
136 | } | |
137 | } | |
dfeec247 | 138 | TyKind::Rptr(_, MutTy { ty: inner_ty, mutbl: Mutability::Not }) => { |
ba9703b0 | 139 | if let Some(impl_did) = cx.tcx.impl_of_method(ty.hir_id.owner.to_def_id()) { |
48663c56 XL |
140 | if cx.tcx.impl_trait_ref(impl_did).is_some() { |
141 | return; | |
532ac7d7 XL |
142 | } |
143 | } | |
48663c56 | 144 | if let Some(t) = is_ty_or_ty_ctxt(cx, &inner_ty) { |
74b04a01 XL |
145 | cx.struct_span_lint(TY_PASS_BY_REFERENCE, ty.span, |lint| { |
146 | lint.build(&format!("passing `{}` by reference", t)) | |
147 | .span_suggestion( | |
148 | ty.span, | |
149 | "try passing by value", | |
150 | t, | |
151 | // Changing type of function argument | |
152 | Applicability::MaybeIncorrect, | |
153 | ) | |
154 | .emit(); | |
155 | }) | |
48663c56 | 156 | } |
532ac7d7 | 157 | } |
48663c56 | 158 | _ => {} |
532ac7d7 XL |
159 | } |
160 | } | |
161 | } | |
162 | ||
f035d41b | 163 | fn lint_ty_kind_usage(cx: &LateContext<'_>, segment: &PathSegment<'_>) -> bool { |
e1599b0c XL |
164 | if let Some(res) = segment.res { |
165 | if let Some(did) = res.opt_def_id() { | |
166 | return cx.tcx.is_diagnostic_item(sym::TyKind, did); | |
532ac7d7 XL |
167 | } |
168 | } | |
169 | ||
170 | false | |
171 | } | |
48663c56 | 172 | |
f035d41b | 173 | fn is_ty_or_ty_ctxt(cx: &LateContext<'_>, ty: &Ty<'_>) -> Option<String> { |
ba9703b0 XL |
174 | if let TyKind::Path(qpath) = &ty.kind { |
175 | if let QPath::Resolved(_, path) = qpath { | |
1b1a35ee XL |
176 | match path.res { |
177 | Res::Def(_, did) => { | |
178 | if cx.tcx.is_diagnostic_item(sym::Ty, did) { | |
179 | return Some(format!("Ty{}", gen_args(path.segments.last().unwrap()))); | |
180 | } else if cx.tcx.is_diagnostic_item(sym::TyCtxt, did) { | |
181 | return Some(format!("TyCtxt{}", gen_args(path.segments.last().unwrap()))); | |
182 | } | |
183 | } | |
184 | // Only lint on `&Ty` and `&TyCtxt` if it is used outside of a trait. | |
185 | Res::SelfTy(None, Some((did, _))) => { | |
186 | if let ty::Adt(adt, substs) = cx.tcx.type_of(did).kind() { | |
187 | if cx.tcx.is_diagnostic_item(sym::Ty, adt.did) { | |
188 | // NOTE: This path is currently unreachable as `Ty<'tcx>` is | |
189 | // defined as a type alias meaning that `impl<'tcx> Ty<'tcx>` | |
190 | // is not actually allowed. | |
191 | // | |
192 | // I(@lcnr) still kept this branch in so we don't miss this | |
193 | // if we ever change it in the future. | |
194 | return Some(format!("Ty<{}>", substs[0])); | |
195 | } else if cx.tcx.is_diagnostic_item(sym::TyCtxt, adt.did) { | |
196 | return Some(format!("TyCtxt<{}>", substs[0])); | |
197 | } | |
198 | } | |
199 | } | |
200 | _ => (), | |
48663c56 XL |
201 | } |
202 | } | |
48663c56 XL |
203 | } |
204 | ||
205 | None | |
206 | } | |
207 | ||
dfeec247 | 208 | fn gen_args(segment: &PathSegment<'_>) -> String { |
48663c56 XL |
209 | if let Some(args) = &segment.args { |
210 | let lifetimes = args | |
211 | .args | |
212 | .iter() | |
213 | .filter_map(|arg| { | |
214 | if let GenericArg::Lifetime(lt) = arg { | |
215 | Some(lt.name.ident().to_string()) | |
216 | } else { | |
217 | None | |
218 | } | |
219 | }) | |
220 | .collect::<Vec<_>>(); | |
221 | ||
222 | if !lifetimes.is_empty() { | |
223 | return format!("<{}>", lifetimes.join(", ")); | |
224 | } | |
225 | } | |
226 | ||
227 | String::new() | |
228 | } | |
416331ca XL |
229 | |
230 | declare_tool_lint! { | |
231 | pub rustc::LINT_PASS_IMPL_WITHOUT_MACRO, | |
232 | Allow, | |
233 | "`impl LintPass` without the `declare_lint_pass!` or `impl_lint_pass!` macros" | |
234 | } | |
235 | ||
236 | declare_lint_pass!(LintPassImpl => [LINT_PASS_IMPL_WITHOUT_MACRO]); | |
237 | ||
238 | impl EarlyLintPass for LintPassImpl { | |
136023e0 XL |
239 | fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) { |
240 | if let ast::ItemKind::Impl(box ast::ImplKind { of_trait: Some(lint_pass), .. }) = &item.kind | |
241 | { | |
416331ca XL |
242 | if let Some(last) = lint_pass.path.segments.last() { |
243 | if last.ident.name == sym::LintPass { | |
e1599b0c XL |
244 | let expn_data = lint_pass.path.span.ctxt().outer_expn_data(); |
245 | let call_site = expn_data.call_site; | |
136023e0 XL |
246 | if expn_data.kind != ExpnKind::Macro(MacroKind::Bang, sym::impl_lint_pass) |
247 | && call_site.ctxt().outer_expn_data().kind | |
248 | != ExpnKind::Macro(MacroKind::Bang, sym::declare_lint_pass) | |
249 | { | |
e1599b0c XL |
250 | cx.struct_span_lint( |
251 | LINT_PASS_IMPL_WITHOUT_MACRO, | |
252 | lint_pass.path.span, | |
74b04a01 XL |
253 | |lint| { |
254 | lint.build("implementing `LintPass` by hand") | |
255 | .help("try using `declare_lint_pass!` or `impl_lint_pass!` instead") | |
256 | .emit(); | |
257 | }, | |
e1599b0c | 258 | ) |
416331ca XL |
259 | } |
260 | } | |
261 | } | |
262 | } | |
263 | } | |
264 | } | |
fc512014 XL |
265 | |
266 | declare_tool_lint! { | |
267 | pub rustc::EXISTING_DOC_KEYWORD, | |
268 | Allow, | |
269 | "Check that documented keywords in std and core actually exist", | |
270 | report_in_external_macro: true | |
271 | } | |
272 | ||
273 | declare_lint_pass!(ExistingDocKeyword => [EXISTING_DOC_KEYWORD]); | |
274 | ||
275 | fn is_doc_keyword(s: Symbol) -> bool { | |
276 | s <= kw::Union | |
277 | } | |
278 | ||
279 | impl<'tcx> LateLintPass<'tcx> for ExistingDocKeyword { | |
280 | fn check_item(&mut self, cx: &LateContext<'_>, item: &rustc_hir::Item<'_>) { | |
6a06907d | 281 | for attr in cx.tcx.hir().attrs(item.hir_id()) { |
fc512014 XL |
282 | if !attr.has_name(sym::doc) { |
283 | continue; | |
284 | } | |
285 | if let Some(list) = attr.meta_item_list() { | |
286 | for nested in list { | |
287 | if nested.has_name(sym::keyword) { | |
288 | let v = nested | |
289 | .value_str() | |
290 | .expect("#[doc(keyword = \"...\")] expected a value!"); | |
291 | if is_doc_keyword(v) { | |
292 | return; | |
293 | } | |
294 | cx.struct_span_lint(EXISTING_DOC_KEYWORD, attr.span, |lint| { | |
295 | lint.build(&format!( | |
296 | "Found non-existing keyword `{}` used in \ | |
297 | `#[doc(keyword = \"...\")]`", | |
298 | v, | |
299 | )) | |
300 | .help("only existing keywords are allowed in core/std") | |
301 | .emit(); | |
302 | }); | |
303 | } | |
304 | } | |
305 | } | |
306 | } | |
307 | } | |
308 | } |