]>
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; |
5099ac24 FG |
8 | use rustc_hir::{Expr, ExprKind, GenericArg, Path, PathSegment, QPath}; |
9 | use rustc_hir::{HirId, Item, ItemKind, Node, Ty, TyKind}; | |
1b1a35ee | 10 | use rustc_middle::ty; |
136023e0 | 11 | use rustc_session::{declare_lint_pass, declare_tool_lint}; |
dfeec247 | 12 | use rustc_span::hygiene::{ExpnKind, MacroKind}; |
136023e0 | 13 | use rustc_span::symbol::{kw, sym, Symbol}; |
532ac7d7 | 14 | |
416331ca XL |
15 | declare_tool_lint! { |
16 | pub rustc::DEFAULT_HASH_TYPES, | |
532ac7d7 | 17 | Allow, |
dfeec247 XL |
18 | "forbid HashMap and HashSet and suggest the FxHash* variants", |
19 | report_in_external_macro: true | |
532ac7d7 XL |
20 | } |
21 | ||
136023e0 XL |
22 | declare_lint_pass!(DefaultHashTypes => [DEFAULT_HASH_TYPES]); |
23 | ||
24 | impl LateLintPass<'_> for DefaultHashTypes { | |
25 | fn check_path(&mut self, cx: &LateContext<'_>, path: &Path<'_>, hir_id: HirId) { | |
26 | let def_id = match path.res { | |
27 | Res::Def(rustc_hir::def::DefKind::Struct, id) => id, | |
28 | _ => return, | |
29 | }; | |
30 | if matches!(cx.tcx.hir().get(hir_id), Node::Item(Item { kind: ItemKind::Use(..), .. })) { | |
31 | // don't lint imports, only actual usages | |
32 | return; | |
532ac7d7 | 33 | } |
c295e0f8 XL |
34 | let replace = match cx.tcx.get_diagnostic_name(def_id) { |
35 | Some(sym::HashMap) => "FxHashMap", | |
36 | Some(sym::HashSet) => "FxHashSet", | |
37 | _ => return, | |
136023e0 XL |
38 | }; |
39 | cx.struct_span_lint(DEFAULT_HASH_TYPES, path.span, |lint| { | |
40 | let msg = format!( | |
41 | "prefer `{}` over `{}`, it has better performance", | |
42 | replace, | |
43 | cx.tcx.item_name(def_id) | |
44 | ); | |
45 | lint.build(&msg) | |
46 | .note(&format!("a `use rustc_data_structures::fx::{}` may be necessary", replace)) | |
47 | .emit(); | |
48 | }); | |
532ac7d7 XL |
49 | } |
50 | } | |
51 | ||
416331ca | 52 | declare_tool_lint! { |
5099ac24 | 53 | pub rustc::POTENTIAL_QUERY_INSTABILITY, |
532ac7d7 | 54 | Allow, |
5099ac24 | 55 | "require explicit opt-in when using potentially unstable methods or functions", |
dfeec247 | 56 | report_in_external_macro: true |
532ac7d7 XL |
57 | } |
58 | ||
5099ac24 FG |
59 | declare_lint_pass!(QueryStability => [POTENTIAL_QUERY_INSTABILITY]); |
60 | ||
61 | impl LateLintPass<'_> for QueryStability { | |
62 | fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) { | |
63 | // FIXME(rustdoc): This lint uses typecheck results, causing rustdoc to | |
64 | // error if there are resolution failures. | |
65 | // | |
66 | // As internal lints are currently always run if there are `unstable_options`, | |
67 | // they are added to the lint store of rustdoc. Internal lints are also | |
68 | // not used via the `lint_mod` query. Crate lints run outside of a query | |
69 | // so rustdoc currently doesn't disable them. | |
70 | // | |
71 | // Instead of relying on this, either change crate lints to a query disabled by | |
72 | // rustdoc, only run internal lints if the user is explicitly opting in | |
73 | // or figure out a different way to avoid running lints for rustdoc. | |
74 | if cx.tcx.sess.opts.actually_rustdoc { | |
75 | return; | |
76 | } | |
77 | ||
78 | let (span, def_id, substs) = match expr.kind { | |
79 | ExprKind::MethodCall(segment, _, _) | |
80 | if let Some(def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) => | |
81 | { | |
82 | (segment.ident.span, def_id, cx.typeck_results().node_substs(expr.hir_id)) | |
83 | }, | |
84 | _ => { | |
85 | let &ty::FnDef(def_id, substs) = | |
86 | cx.typeck_results() | |
87 | .node_type(expr.hir_id) | |
88 | .kind() else { return }; | |
89 | (expr.span, def_id, substs) | |
90 | } | |
91 | }; | |
92 | if let Ok(Some(instance)) = ty::Instance::resolve(cx.tcx, cx.param_env, def_id, substs) { | |
93 | let def_id = instance.def_id(); | |
94 | if cx.tcx.has_attr(def_id, sym::rustc_lint_query_instability) { | |
95 | cx.struct_span_lint(POTENTIAL_QUERY_INSTABILITY, span, |lint| { | |
96 | let msg = format!( | |
97 | "using `{}` can result in unstable query results", | |
98 | cx.tcx.item_name(def_id) | |
99 | ); | |
100 | lint.build(&msg) | |
101 | .note("if you believe this case to be fine, allow this lint and add a comment explaining your rationale") | |
102 | .emit(); | |
103 | }) | |
104 | } | |
105 | } | |
106 | } | |
107 | } | |
108 | ||
416331ca | 109 | declare_tool_lint! { |
5099ac24 | 110 | pub rustc::USAGE_OF_TY_TYKIND, |
48663c56 | 111 | Allow, |
5099ac24 | 112 | "usage of `ty::TyKind` outside of the `ty::sty` module", |
dfeec247 | 113 | report_in_external_macro: true |
48663c56 XL |
114 | } |
115 | ||
416331ca XL |
116 | declare_tool_lint! { |
117 | pub rustc::USAGE_OF_QUALIFIED_TY, | |
48663c56 | 118 | Allow, |
dfeec247 XL |
119 | "using `ty::{Ty,TyCtxt}` instead of importing it", |
120 | report_in_external_macro: true | |
48663c56 XL |
121 | } |
122 | ||
123 | declare_lint_pass!(TyTyKind => [ | |
124 | USAGE_OF_TY_TYKIND, | |
48663c56 XL |
125 | USAGE_OF_QUALIFIED_TY, |
126 | ]); | |
532ac7d7 | 127 | |
f035d41b XL |
128 | impl<'tcx> LateLintPass<'tcx> for TyTyKind { |
129 | fn check_path(&mut self, cx: &LateContext<'_>, path: &'tcx Path<'tcx>, _: HirId) { | |
532ac7d7 XL |
130 | let segments = path.segments.iter().rev().skip(1).rev(); |
131 | ||
132 | if let Some(last) = segments.last() { | |
133 | let span = path.span.with_hi(last.ident.span.hi()); | |
134 | if lint_ty_kind_usage(cx, last) { | |
74b04a01 XL |
135 | cx.struct_span_lint(USAGE_OF_TY_TYKIND, span, |lint| { |
136 | lint.build("usage of `ty::TyKind::<kind>`") | |
137 | .span_suggestion( | |
138 | span, | |
139 | "try using ty::<kind> directly", | |
140 | "ty".to_string(), | |
141 | Applicability::MaybeIncorrect, // ty maybe needs an import | |
142 | ) | |
143 | .emit(); | |
144 | }) | |
532ac7d7 XL |
145 | } |
146 | } | |
147 | } | |
148 | ||
f035d41b | 149 | fn check_ty(&mut self, cx: &LateContext<'_>, ty: &'tcx Ty<'tcx>) { |
e74abb32 | 150 | match &ty.kind { |
3c0e092e XL |
151 | TyKind::Path(QPath::Resolved(_, path)) => { |
152 | if let Some(last) = path.segments.iter().last() { | |
153 | if lint_ty_kind_usage(cx, last) { | |
154 | cx.struct_span_lint(USAGE_OF_TY_TYKIND, path.span, |lint| { | |
155 | lint.build("usage of `ty::TyKind`") | |
156 | .help("try using `Ty` instead") | |
157 | .emit(); | |
158 | }) | |
159 | } else { | |
160 | if ty.span.from_expansion() { | |
161 | return; | |
162 | } | |
163 | if let Some(t) = is_ty_or_ty_ctxt(cx, ty) { | |
164 | if path.segments.len() > 1 { | |
165 | cx.struct_span_lint(USAGE_OF_QUALIFIED_TY, path.span, |lint| { | |
166 | lint.build(&format!("usage of qualified `ty::{}`", t)) | |
167 | .span_suggestion( | |
168 | path.span, | |
5099ac24 | 169 | "try importing it and using it unqualified", |
3c0e092e XL |
170 | t, |
171 | // The import probably needs to be changed | |
172 | Applicability::MaybeIncorrect, | |
173 | ) | |
174 | .emit(); | |
175 | }) | |
48663c56 XL |
176 | } |
177 | } | |
178 | } | |
179 | } | |
180 | } | |
48663c56 | 181 | _ => {} |
532ac7d7 XL |
182 | } |
183 | } | |
184 | } | |
185 | ||
f035d41b | 186 | fn lint_ty_kind_usage(cx: &LateContext<'_>, segment: &PathSegment<'_>) -> bool { |
e1599b0c XL |
187 | if let Some(res) = segment.res { |
188 | if let Some(did) = res.opt_def_id() { | |
189 | return cx.tcx.is_diagnostic_item(sym::TyKind, did); | |
532ac7d7 XL |
190 | } |
191 | } | |
192 | ||
193 | false | |
194 | } | |
48663c56 | 195 | |
f035d41b | 196 | fn is_ty_or_ty_ctxt(cx: &LateContext<'_>, ty: &Ty<'_>) -> Option<String> { |
3c0e092e XL |
197 | if let TyKind::Path(QPath::Resolved(_, path)) = &ty.kind { |
198 | match path.res { | |
199 | Res::Def(_, def_id) => { | |
200 | if let Some(name @ (sym::Ty | sym::TyCtxt)) = cx.tcx.get_diagnostic_name(def_id) { | |
201 | return Some(format!("{}{}", name, gen_args(path.segments.last().unwrap()))); | |
1b1a35ee | 202 | } |
3c0e092e XL |
203 | } |
204 | // Only lint on `&Ty` and `&TyCtxt` if it is used outside of a trait. | |
5099ac24 | 205 | Res::SelfTy { trait_: None, alias_to: Some((did, _)) } => { |
3c0e092e XL |
206 | if let ty::Adt(adt, substs) = cx.tcx.type_of(did).kind() { |
207 | if let Some(name @ (sym::Ty | sym::TyCtxt)) = | |
208 | cx.tcx.get_diagnostic_name(adt.did) | |
209 | { | |
210 | // NOTE: This path is currently unreachable as `Ty<'tcx>` is | |
211 | // defined as a type alias meaning that `impl<'tcx> Ty<'tcx>` | |
212 | // is not actually allowed. | |
213 | // | |
214 | // I(@lcnr) still kept this branch in so we don't miss this | |
215 | // if we ever change it in the future. | |
216 | return Some(format!("{}<{}>", name, substs[0])); | |
1b1a35ee XL |
217 | } |
218 | } | |
48663c56 | 219 | } |
3c0e092e | 220 | _ => (), |
48663c56 | 221 | } |
48663c56 XL |
222 | } |
223 | ||
224 | None | |
225 | } | |
226 | ||
dfeec247 | 227 | fn gen_args(segment: &PathSegment<'_>) -> String { |
48663c56 XL |
228 | if let Some(args) = &segment.args { |
229 | let lifetimes = args | |
230 | .args | |
231 | .iter() | |
232 | .filter_map(|arg| { | |
233 | if let GenericArg::Lifetime(lt) = arg { | |
234 | Some(lt.name.ident().to_string()) | |
235 | } else { | |
236 | None | |
237 | } | |
238 | }) | |
239 | .collect::<Vec<_>>(); | |
240 | ||
241 | if !lifetimes.is_empty() { | |
242 | return format!("<{}>", lifetimes.join(", ")); | |
243 | } | |
244 | } | |
245 | ||
246 | String::new() | |
247 | } | |
416331ca XL |
248 | |
249 | declare_tool_lint! { | |
250 | pub rustc::LINT_PASS_IMPL_WITHOUT_MACRO, | |
251 | Allow, | |
252 | "`impl LintPass` without the `declare_lint_pass!` or `impl_lint_pass!` macros" | |
253 | } | |
254 | ||
255 | declare_lint_pass!(LintPassImpl => [LINT_PASS_IMPL_WITHOUT_MACRO]); | |
256 | ||
257 | impl EarlyLintPass for LintPassImpl { | |
136023e0 | 258 | fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) { |
3c0e092e | 259 | if let ast::ItemKind::Impl(box ast::Impl { of_trait: Some(lint_pass), .. }) = &item.kind { |
416331ca XL |
260 | if let Some(last) = lint_pass.path.segments.last() { |
261 | if last.ident.name == sym::LintPass { | |
e1599b0c XL |
262 | let expn_data = lint_pass.path.span.ctxt().outer_expn_data(); |
263 | let call_site = expn_data.call_site; | |
136023e0 XL |
264 | if expn_data.kind != ExpnKind::Macro(MacroKind::Bang, sym::impl_lint_pass) |
265 | && call_site.ctxt().outer_expn_data().kind | |
266 | != ExpnKind::Macro(MacroKind::Bang, sym::declare_lint_pass) | |
267 | { | |
e1599b0c XL |
268 | cx.struct_span_lint( |
269 | LINT_PASS_IMPL_WITHOUT_MACRO, | |
270 | lint_pass.path.span, | |
74b04a01 XL |
271 | |lint| { |
272 | lint.build("implementing `LintPass` by hand") | |
273 | .help("try using `declare_lint_pass!` or `impl_lint_pass!` instead") | |
274 | .emit(); | |
275 | }, | |
e1599b0c | 276 | ) |
416331ca XL |
277 | } |
278 | } | |
279 | } | |
280 | } | |
281 | } | |
282 | } | |
fc512014 XL |
283 | |
284 | declare_tool_lint! { | |
285 | pub rustc::EXISTING_DOC_KEYWORD, | |
286 | Allow, | |
287 | "Check that documented keywords in std and core actually exist", | |
288 | report_in_external_macro: true | |
289 | } | |
290 | ||
291 | declare_lint_pass!(ExistingDocKeyword => [EXISTING_DOC_KEYWORD]); | |
292 | ||
293 | fn is_doc_keyword(s: Symbol) -> bool { | |
294 | s <= kw::Union | |
295 | } | |
296 | ||
297 | impl<'tcx> LateLintPass<'tcx> for ExistingDocKeyword { | |
298 | fn check_item(&mut self, cx: &LateContext<'_>, item: &rustc_hir::Item<'_>) { | |
6a06907d | 299 | for attr in cx.tcx.hir().attrs(item.hir_id()) { |
fc512014 XL |
300 | if !attr.has_name(sym::doc) { |
301 | continue; | |
302 | } | |
303 | if let Some(list) = attr.meta_item_list() { | |
304 | for nested in list { | |
305 | if nested.has_name(sym::keyword) { | |
306 | let v = nested | |
307 | .value_str() | |
308 | .expect("#[doc(keyword = \"...\")] expected a value!"); | |
309 | if is_doc_keyword(v) { | |
310 | return; | |
311 | } | |
312 | cx.struct_span_lint(EXISTING_DOC_KEYWORD, attr.span, |lint| { | |
313 | lint.build(&format!( | |
314 | "Found non-existing keyword `{}` used in \ | |
315 | `#[doc(keyword = \"...\")]`", | |
316 | v, | |
317 | )) | |
318 | .help("only existing keywords are allowed in core/std") | |
319 | .emit(); | |
320 | }); | |
321 | } | |
322 | } | |
323 | } | |
324 | } | |
325 | } | |
326 | } |