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Commit | Line | Data |
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041b39d2 XL |
1 | //! This module implements some validity checks for attributes. |
2 | //! In particular it verifies that `#[inline]` and `#[repr]` attributes are | |
3 | //! attached to items that actually support them and if there are | |
4 | //! conflicts between multiple such attributes attached to the same | |
5 | //! item. | |
6 | ||
ba9703b0 XL |
7 | use rustc_middle::hir::map::Map; |
8 | use rustc_middle::ty::query::Providers; | |
9 | use rustc_middle::ty::TyCtxt; | |
e1599b0c | 10 | |
94222f64 | 11 | use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, NestedMetaItem}; |
c295e0f8 | 12 | use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
cdc7bbd5 | 13 | use rustc_errors::{pluralize, struct_span_err, Applicability}; |
94222f64 | 14 | use rustc_feature::{AttributeType, BUILTIN_ATTRIBUTE_MAP}; |
dfeec247 | 15 | use rustc_hir as hir; |
f035d41b | 16 | use rustc_hir::def_id::LocalDefId; |
dfeec247 | 17 | use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; |
17df50a5 | 18 | use rustc_hir::{self, FnSig, ForeignItem, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID}; |
74b04a01 | 19 | use rustc_hir::{MethodKind, Target}; |
6a06907d XL |
20 | use rustc_session::lint::builtin::{ |
21 | CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, UNUSED_ATTRIBUTES, | |
22 | }; | |
74b04a01 | 23 | use rustc_session::parse::feature_err; |
29967ef6 | 24 | use rustc_span::symbol::{sym, Symbol}; |
17df50a5 | 25 | use rustc_span::{MultiSpan, Span, DUMMY_SP}; |
b039eaaf | 26 | |
f035d41b XL |
27 | pub(crate) fn target_from_impl_item<'tcx>( |
28 | tcx: TyCtxt<'tcx>, | |
29 | impl_item: &hir::ImplItem<'_>, | |
30 | ) -> Target { | |
74b04a01 XL |
31 | match impl_item.kind { |
32 | hir::ImplItemKind::Const(..) => Target::AssocConst, | |
ba9703b0 | 33 | hir::ImplItemKind::Fn(..) => { |
6a06907d | 34 | let parent_hir_id = tcx.hir().get_parent_item(impl_item.hir_id()); |
74b04a01 XL |
35 | let containing_item = tcx.hir().expect_item(parent_hir_id); |
36 | let containing_impl_is_for_trait = match &containing_item.kind { | |
5869c6ff | 37 | hir::ItemKind::Impl(impl_) => impl_.of_trait.is_some(), |
74b04a01 XL |
38 | _ => bug!("parent of an ImplItem must be an Impl"), |
39 | }; | |
40 | if containing_impl_is_for_trait { | |
e74abb32 | 41 | Target::Method(MethodKind::Trait { body: true }) |
74b04a01 XL |
42 | } else { |
43 | Target::Method(MethodKind::Inherent) | |
e74abb32 | 44 | } |
b039eaaf | 45 | } |
f035d41b | 46 | hir::ImplItemKind::TyAlias(..) => Target::AssocTy, |
b039eaaf SL |
47 | } |
48 | } | |
49 | ||
1b1a35ee XL |
50 | #[derive(Clone, Copy)] |
51 | enum ItemLike<'tcx> { | |
52 | Item(&'tcx Item<'tcx>), | |
53 | ForeignItem(&'tcx ForeignItem<'tcx>), | |
54 | } | |
55 | ||
dc9dc135 XL |
56 | struct CheckAttrVisitor<'tcx> { |
57 | tcx: TyCtxt<'tcx>, | |
b039eaaf SL |
58 | } |
59 | ||
dc9dc135 | 60 | impl CheckAttrVisitor<'tcx> { |
9fa01778 | 61 | /// Checks any attribute. |
e74abb32 XL |
62 | fn check_attributes( |
63 | &self, | |
64 | hir_id: HirId, | |
e74abb32 XL |
65 | span: &Span, |
66 | target: Target, | |
1b1a35ee | 67 | item: Option<ItemLike<'_>>, |
e74abb32 | 68 | ) { |
c295e0f8 | 69 | let mut doc_aliases = FxHashMap::default(); |
e74abb32 | 70 | let mut is_valid = true; |
17df50a5 | 71 | let mut specified_inline = None; |
94222f64 | 72 | let mut seen = FxHashSet::default(); |
6a06907d | 73 | let attrs = self.tcx.hir().attrs(hir_id); |
e74abb32 | 74 | for attr in attrs { |
94222f64 | 75 | let attr_is_valid = match attr.name_or_empty() { |
cdc7bbd5 XL |
76 | sym::inline => self.check_inline(hir_id, attr, span, target), |
77 | sym::non_exhaustive => self.check_non_exhaustive(hir_id, attr, span, target), | |
78 | sym::marker => self.check_marker(hir_id, attr, span, target), | |
79 | sym::target_feature => self.check_target_feature(hir_id, attr, span, target), | |
80 | sym::track_caller => { | |
81 | self.check_track_caller(hir_id, &attr.span, attrs, span, target) | |
1b1a35ee | 82 | } |
c295e0f8 XL |
83 | sym::doc => self.check_doc_attrs( |
84 | attr, | |
85 | hir_id, | |
86 | target, | |
87 | &mut specified_inline, | |
88 | &mut doc_aliases, | |
89 | ), | |
cdc7bbd5 XL |
90 | sym::no_link => self.check_no_link(hir_id, &attr, span, target), |
91 | sym::export_name => self.check_export_name(hir_id, &attr, span, target), | |
cdc7bbd5 XL |
92 | sym::rustc_layout_scalar_valid_range_start |
93 | | sym::rustc_layout_scalar_valid_range_end => { | |
94 | self.check_rustc_layout_scalar_valid_range(&attr, span, target) | |
95 | } | |
96 | sym::allow_internal_unstable => { | |
97 | self.check_allow_internal_unstable(hir_id, &attr, span, target, &attrs) | |
98 | } | |
99 | sym::rustc_allow_const_fn_unstable => { | |
100 | self.check_rustc_allow_const_fn_unstable(hir_id, &attr, span, target) | |
101 | } | |
102 | sym::naked => self.check_naked(hir_id, attr, span, target), | |
103 | sym::rustc_legacy_const_generics => { | |
104 | self.check_rustc_legacy_const_generics(&attr, span, target, item) | |
105 | } | |
106 | sym::rustc_clean | |
107 | | sym::rustc_dirty | |
108 | | sym::rustc_if_this_changed | |
109 | | sym::rustc_then_this_would_need => self.check_rustc_dirty_clean(&attr), | |
136023e0 XL |
110 | sym::cmse_nonsecure_entry => self.check_cmse_nonsecure_entry(attr, span, target), |
111 | sym::default_method_body_is_const => { | |
112 | self.check_default_method_body_is_const(attr, span, target) | |
113 | } | |
c295e0f8 | 114 | sym::must_not_suspend => self.check_must_not_suspend(&attr, span, target), |
94222f64 XL |
115 | sym::rustc_const_unstable |
116 | | sym::rustc_const_stable | |
117 | | sym::unstable | |
118 | | sym::stable | |
119 | | sym::rustc_promotable => self.check_stability_promotable(&attr, span, target), | |
cdc7bbd5 | 120 | _ => true, |
e74abb32 | 121 | }; |
94222f64 XL |
122 | is_valid &= attr_is_valid; |
123 | ||
cdc7bbd5 XL |
124 | // lint-only checks |
125 | match attr.name_or_empty() { | |
126 | sym::cold => self.check_cold(hir_id, attr, span, target), | |
127 | sym::link_name => self.check_link_name(hir_id, attr, span, target), | |
128 | sym::link_section => self.check_link_section(hir_id, attr, span, target), | |
129 | sym::no_mangle => self.check_no_mangle(hir_id, attr, span, target), | |
94222f64 XL |
130 | sym::deprecated | sym::rustc_deprecated => { |
131 | self.check_deprecated(hir_id, attr, span, target) | |
132 | } | |
133 | sym::macro_use | sym::macro_escape => self.check_macro_use(hir_id, attr, target), | |
134 | sym::path => self.check_generic_attr(hir_id, attr, target, &[Target::Mod]), | |
135 | sym::cfg_attr => self.check_cfg_attr(hir_id, attr), | |
136 | sym::plugin_registrar => self.check_plugin_registrar(hir_id, attr, target), | |
137 | sym::macro_export => self.check_macro_export(hir_id, attr, target), | |
138 | sym::ignore | sym::should_panic | sym::proc_macro_derive => { | |
139 | self.check_generic_attr(hir_id, attr, target, &[Target::Fn]) | |
140 | } | |
141 | sym::automatically_derived => { | |
142 | self.check_generic_attr(hir_id, attr, target, &[Target::Impl]) | |
143 | } | |
144 | sym::no_implicit_prelude => { | |
145 | self.check_generic_attr(hir_id, attr, target, &[Target::Mod]) | |
146 | } | |
147 | _ => {} | |
148 | } | |
149 | ||
150 | if hir_id != CRATE_HIR_ID { | |
151 | if let Some((_, AttributeType::CrateLevel, ..)) = | |
152 | attr.ident().and_then(|ident| BUILTIN_ATTRIBUTE_MAP.get(&ident.name)) | |
153 | { | |
154 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
155 | let msg = match attr.style { | |
156 | ast::AttrStyle::Outer => { | |
157 | "crate-level attribute should be an inner attribute: add an exclamation \ | |
158 | mark: `#![foo]`" | |
159 | } | |
160 | ast::AttrStyle::Inner => "crate-level attribute should be in the root module", | |
161 | }; | |
162 | lint.build(msg).emit() | |
163 | }); | |
164 | } | |
165 | } | |
166 | ||
167 | // Duplicate attributes | |
168 | match attr.name_or_empty() { | |
169 | name @ sym::macro_use => { | |
170 | let args = attr.meta_item_list().unwrap_or_else(Vec::new); | |
171 | let args: Vec<_> = args.iter().map(|arg| arg.name_or_empty()).collect(); | |
172 | if !seen.insert((name, args)) { | |
173 | self.tcx.struct_span_lint_hir( | |
174 | UNUSED_ATTRIBUTES, | |
175 | hir_id, | |
176 | attr.span, | |
177 | |lint| lint.build("unused attribute").emit(), | |
178 | ); | |
179 | } | |
180 | } | |
cdc7bbd5 XL |
181 | _ => {} |
182 | } | |
041b39d2 | 183 | } |
2c00a5a8 | 184 | |
e74abb32 XL |
185 | if !is_valid { |
186 | return; | |
187 | } | |
188 | ||
29967ef6 | 189 | if matches!(target, Target::Closure | Target::Fn | Target::Method(_) | Target::ForeignFn) { |
f9f354fc | 190 | self.tcx.ensure().codegen_fn_attrs(self.tcx.hir().local_def_id(hir_id)); |
e74abb32 XL |
191 | } |
192 | ||
dfeec247 | 193 | self.check_repr(attrs, span, target, item, hir_id); |
e74abb32 XL |
194 | self.check_used(attrs, target); |
195 | } | |
196 | ||
5869c6ff XL |
197 | fn inline_attr_str_error_with_macro_def(&self, hir_id: HirId, attr: &Attribute, sym: &str) { |
198 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
199 | lint.build(&format!( | |
200 | "`#[{}]` is ignored on struct fields, match arms and macro defs", | |
201 | sym, | |
202 | )) | |
203 | .warn( | |
204 | "this was previously accepted by the compiler but is \ | |
205 | being phased out; it will become a hard error in \ | |
206 | a future release!", | |
207 | ) | |
208 | .note( | |
209 | "see issue #80564 <https://github.com/rust-lang/rust/issues/80564> \ | |
210 | for more information", | |
211 | ) | |
212 | .emit(); | |
213 | }); | |
214 | } | |
215 | ||
216 | fn inline_attr_str_error_without_macro_def(&self, hir_id: HirId, attr: &Attribute, sym: &str) { | |
217 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
218 | lint.build(&format!("`#[{}]` is ignored on struct fields and match arms", sym)) | |
219 | .warn( | |
220 | "this was previously accepted by the compiler but is \ | |
221 | being phased out; it will become a hard error in \ | |
222 | a future release!", | |
223 | ) | |
224 | .note( | |
225 | "see issue #80564 <https://github.com/rust-lang/rust/issues/80564> \ | |
226 | for more information", | |
227 | ) | |
228 | .emit(); | |
229 | }); | |
230 | } | |
231 | ||
e74abb32 XL |
232 | /// Checks if an `#[inline]` is applied to a function or a closure. Returns `true` if valid. |
233 | fn check_inline(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { | |
234 | match target { | |
dfeec247 XL |
235 | Target::Fn |
236 | | Target::Closure | |
ba9703b0 | 237 | | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, |
e74abb32 | 238 | Target::Method(MethodKind::Trait { body: false }) | Target::ForeignFn => { |
74b04a01 XL |
239 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
240 | lint.build("`#[inline]` is ignored on function prototypes").emit() | |
241 | }); | |
e74abb32 XL |
242 | true |
243 | } | |
244 | // FIXME(#65833): We permit associated consts to have an `#[inline]` attribute with | |
245 | // just a lint, because we previously erroneously allowed it and some crates used it | |
246 | // accidentally, to to be compatible with crates depending on them, we can't throw an | |
247 | // error here. | |
248 | Target::AssocConst => { | |
74b04a01 XL |
249 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
250 | lint.build("`#[inline]` is ignored on constants") | |
251 | .warn( | |
252 | "this was previously accepted by the compiler but is \ | |
1b1a35ee XL |
253 | being phased out; it will become a hard error in \ |
254 | a future release!", | |
74b04a01 XL |
255 | ) |
256 | .note( | |
257 | "see issue #65833 <https://github.com/rust-lang/rust/issues/65833> \ | |
1b1a35ee | 258 | for more information", |
74b04a01 XL |
259 | ) |
260 | .emit(); | |
261 | }); | |
e74abb32 XL |
262 | true |
263 | } | |
5869c6ff XL |
264 | // FIXME(#80564): Same for fields, arms, and macro defs |
265 | Target::Field | Target::Arm | Target::MacroDef => { | |
266 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "inline"); | |
267 | true | |
268 | } | |
e74abb32 XL |
269 | _ => { |
270 | struct_span_err!( | |
271 | self.tcx.sess, | |
272 | attr.span, | |
273 | E0518, | |
274 | "attribute should be applied to function or closure", | |
dfeec247 XL |
275 | ) |
276 | .span_label(*span, "not a function or closure") | |
277 | .emit(); | |
e74abb32 XL |
278 | false |
279 | } | |
280 | } | |
041b39d2 XL |
281 | } |
282 | ||
94222f64 XL |
283 | fn check_generic_attr( |
284 | &self, | |
285 | hir_id: HirId, | |
286 | attr: &Attribute, | |
287 | target: Target, | |
288 | allowed_targets: &[Target], | |
289 | ) { | |
290 | if !allowed_targets.iter().any(|t| t == &target) { | |
291 | let name = attr.name_or_empty(); | |
292 | let mut i = allowed_targets.iter(); | |
293 | // Pluralize | |
294 | let b = i.next().map_or_else(String::new, |t| t.to_string() + "s"); | |
295 | let supported_names = i.enumerate().fold(b, |mut b, (i, allowed_target)| { | |
296 | if allowed_targets.len() > 2 && i == allowed_targets.len() - 2 { | |
297 | b.push_str(", and "); | |
298 | } else if allowed_targets.len() == 2 && i == allowed_targets.len() - 2 { | |
299 | b.push_str(" and "); | |
300 | } else { | |
301 | b.push_str(", "); | |
302 | } | |
303 | // Pluralize | |
304 | b.push_str(&(allowed_target.to_string() + "s")); | |
305 | b | |
306 | }); | |
307 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
308 | lint.build(&format!("`#[{name}]` only has an effect on {}", supported_names)) | |
309 | .emit(); | |
310 | }); | |
311 | } | |
312 | } | |
313 | ||
fc512014 | 314 | /// Checks if `#[naked]` is applied to a function definition. |
5869c6ff | 315 | fn check_naked(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { |
fc512014 XL |
316 | match target { |
317 | Target::Fn | |
318 | | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, | |
5869c6ff XL |
319 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
320 | // `#[allow_internal_unstable]` attribute with just a lint, because we previously | |
321 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
322 | // with crates depending on them, we can't throw an error here. | |
323 | Target::Field | Target::Arm | Target::MacroDef => { | |
324 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "naked"); | |
325 | true | |
326 | } | |
fc512014 XL |
327 | _ => { |
328 | self.tcx | |
329 | .sess | |
330 | .struct_span_err( | |
331 | attr.span, | |
332 | "attribute should be applied to a function definition", | |
333 | ) | |
334 | .span_label(*span, "not a function definition") | |
335 | .emit(); | |
336 | false | |
337 | } | |
338 | } | |
339 | } | |
340 | ||
136023e0 XL |
341 | /// Checks if `#[cmse_nonsecure_entry]` is applied to a function definition. |
342 | fn check_cmse_nonsecure_entry(&self, attr: &Attribute, span: &Span, target: Target) -> bool { | |
343 | match target { | |
344 | Target::Fn | |
345 | | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, | |
346 | _ => { | |
347 | self.tcx | |
348 | .sess | |
349 | .struct_span_err( | |
350 | attr.span, | |
351 | "attribute should be applied to a function definition", | |
352 | ) | |
353 | .span_label(*span, "not a function definition") | |
354 | .emit(); | |
355 | false | |
356 | } | |
357 | } | |
358 | } | |
359 | ||
e74abb32 XL |
360 | /// Checks if a `#[track_caller]` is applied to a non-naked function. Returns `true` if valid. |
361 | fn check_track_caller( | |
362 | &self, | |
5869c6ff | 363 | hir_id: HirId, |
e74abb32 | 364 | attr_span: &Span, |
dfeec247 | 365 | attrs: &'hir [Attribute], |
e74abb32 XL |
366 | span: &Span, |
367 | target: Target, | |
368 | ) -> bool { | |
369 | match target { | |
fc512014 | 370 | _ if attrs.iter().any(|attr| attr.has_name(sym::naked)) => { |
e74abb32 XL |
371 | struct_span_err!( |
372 | self.tcx.sess, | |
373 | *attr_span, | |
374 | E0736, | |
375 | "cannot use `#[track_caller]` with `#[naked]`", | |
dfeec247 XL |
376 | ) |
377 | .emit(); | |
e74abb32 XL |
378 | false |
379 | } | |
1b1a35ee | 380 | Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => true, |
5869c6ff XL |
381 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
382 | // `#[track_caller]` attribute with just a lint, because we previously | |
383 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
384 | // with crates depending on them, we can't throw an error here. | |
385 | Target::Field | Target::Arm | Target::MacroDef => { | |
386 | for attr in attrs { | |
387 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "track_caller"); | |
388 | } | |
389 | true | |
390 | } | |
e74abb32 XL |
391 | _ => { |
392 | struct_span_err!( | |
393 | self.tcx.sess, | |
394 | *attr_span, | |
395 | E0739, | |
396 | "attribute should be applied to function" | |
397 | ) | |
398 | .span_label(*span, "not a function") | |
83c7162d | 399 | .emit(); |
e74abb32 XL |
400 | false |
401 | } | |
83c7162d XL |
402 | } |
403 | } | |
404 | ||
e74abb32 | 405 | /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid. Returns `true` if valid. |
5869c6ff XL |
406 | fn check_non_exhaustive( |
407 | &self, | |
408 | hir_id: HirId, | |
409 | attr: &Attribute, | |
410 | span: &Span, | |
411 | target: Target, | |
412 | ) -> bool { | |
83c7162d | 413 | match target { |
29967ef6 | 414 | Target::Struct | Target::Enum | Target::Variant => true, |
5869c6ff XL |
415 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
416 | // `#[non_exhaustive]` attribute with just a lint, because we previously | |
417 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
418 | // with crates depending on them, we can't throw an error here. | |
419 | Target::Field | Target::Arm | Target::MacroDef => { | |
420 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "non_exhaustive"); | |
421 | true | |
422 | } | |
83c7162d | 423 | _ => { |
dfeec247 XL |
424 | struct_span_err!( |
425 | self.tcx.sess, | |
426 | attr.span, | |
427 | E0701, | |
428 | "attribute can only be applied to a struct or enum" | |
429 | ) | |
430 | .span_label(*span, "not a struct or enum") | |
431 | .emit(); | |
e74abb32 | 432 | false |
83c7162d XL |
433 | } |
434 | } | |
b039eaaf SL |
435 | } |
436 | ||
e74abb32 | 437 | /// Checks if the `#[marker]` attribute on an `item` is valid. Returns `true` if valid. |
5869c6ff | 438 | fn check_marker(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { |
0bf4aa26 | 439 | match target { |
e74abb32 | 440 | Target::Trait => true, |
5869c6ff XL |
441 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
442 | // `#[marker]` attribute with just a lint, because we previously | |
443 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
444 | // with crates depending on them, we can't throw an error here. | |
445 | Target::Field | Target::Arm | Target::MacroDef => { | |
446 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "marker"); | |
447 | true | |
448 | } | |
0bf4aa26 | 449 | _ => { |
dfeec247 XL |
450 | self.tcx |
451 | .sess | |
0bf4aa26 | 452 | .struct_span_err(attr.span, "attribute can only be applied to a trait") |
e74abb32 | 453 | .span_label(*span, "not a trait") |
0bf4aa26 | 454 | .emit(); |
e74abb32 | 455 | false |
0bf4aa26 XL |
456 | } |
457 | } | |
0bf4aa26 XL |
458 | } |
459 | ||
e74abb32 | 460 | /// Checks if the `#[target_feature]` attribute on `item` is valid. Returns `true` if valid. |
1b1a35ee XL |
461 | fn check_target_feature( |
462 | &self, | |
463 | hir_id: HirId, | |
464 | attr: &Attribute, | |
465 | span: &Span, | |
466 | target: Target, | |
467 | ) -> bool { | |
e74abb32 | 468 | match target { |
dfeec247 | 469 | Target::Fn |
ba9703b0 | 470 | | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, |
1b1a35ee XL |
471 | // FIXME: #[target_feature] was previously erroneously allowed on statements and some |
472 | // crates used this, so only emit a warning. | |
473 | Target::Statement => { | |
474 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
475 | lint.build("attribute should be applied to a function") | |
476 | .warn( | |
477 | "this was previously accepted by the compiler but is \ | |
478 | being phased out; it will become a hard error in \ | |
479 | a future release!", | |
480 | ) | |
481 | .span_label(*span, "not a function") | |
482 | .emit(); | |
483 | }); | |
484 | true | |
485 | } | |
5869c6ff XL |
486 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
487 | // `#[target_feature]` attribute with just a lint, because we previously | |
488 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
489 | // with crates depending on them, we can't throw an error here. | |
490 | Target::Field | Target::Arm | Target::MacroDef => { | |
491 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "target_feature"); | |
492 | true | |
493 | } | |
e74abb32 | 494 | _ => { |
dfeec247 XL |
495 | self.tcx |
496 | .sess | |
e74abb32 XL |
497 | .struct_span_err(attr.span, "attribute should be applied to a function") |
498 | .span_label(*span, "not a function") | |
499 | .emit(); | |
500 | false | |
dfeec247 | 501 | } |
e74abb32 XL |
502 | } |
503 | } | |
504 | ||
fc512014 | 505 | fn doc_attr_str_error(&self, meta: &NestedMetaItem, attr_name: &str) { |
1b1a35ee XL |
506 | self.tcx |
507 | .sess | |
508 | .struct_span_err( | |
509 | meta.span(), | |
fc512014 | 510 | &format!("doc {0} attribute expects a string: #[doc({0} = \"a\")]", attr_name), |
1b1a35ee XL |
511 | ) |
512 | .emit(); | |
513 | } | |
514 | ||
6a06907d XL |
515 | fn check_doc_alias_value( |
516 | &self, | |
517 | meta: &NestedMetaItem, | |
518 | doc_alias: &str, | |
519 | hir_id: HirId, | |
520 | target: Target, | |
521 | is_list: bool, | |
c295e0f8 | 522 | aliases: &mut FxHashMap<String, Span>, |
6a06907d XL |
523 | ) -> bool { |
524 | let tcx = self.tcx; | |
525 | let err_fn = move |span: Span, msg: &str| { | |
526 | tcx.sess.span_err( | |
527 | span, | |
528 | &format!( | |
529 | "`#[doc(alias{})]` {}", | |
530 | if is_list { "(\"...\")" } else { " = \"...\"" }, | |
531 | msg, | |
532 | ), | |
533 | ); | |
534 | false | |
535 | }; | |
fc512014 | 536 | if doc_alias.is_empty() { |
6a06907d XL |
537 | return err_fn( |
538 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
539 | "attribute cannot have empty value", | |
540 | ); | |
fc512014 XL |
541 | } |
542 | if let Some(c) = | |
543 | doc_alias.chars().find(|&c| c == '"' || c == '\'' || (c.is_whitespace() && c != ' ')) | |
544 | { | |
6a06907d XL |
545 | self.tcx.sess.span_err( |
546 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
547 | &format!( | |
548 | "{:?} character isn't allowed in `#[doc(alias{})]`", | |
549 | c, | |
550 | if is_list { "(\"...\")" } else { " = \"...\"" }, | |
551 | ), | |
552 | ); | |
fc512014 XL |
553 | return false; |
554 | } | |
555 | if doc_alias.starts_with(' ') || doc_alias.ends_with(' ') { | |
6a06907d XL |
556 | return err_fn( |
557 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
558 | "cannot start or end with ' '", | |
559 | ); | |
fc512014 XL |
560 | } |
561 | if let Some(err) = match target { | |
562 | Target::Impl => Some("implementation block"), | |
563 | Target::ForeignMod => Some("extern block"), | |
564 | Target::AssocTy => { | |
565 | let parent_hir_id = self.tcx.hir().get_parent_item(hir_id); | |
566 | let containing_item = self.tcx.hir().expect_item(parent_hir_id); | |
567 | if Target::from_item(containing_item) == Target::Impl { | |
568 | Some("type alias in implementation block") | |
569 | } else { | |
570 | None | |
571 | } | |
572 | } | |
573 | Target::AssocConst => { | |
574 | let parent_hir_id = self.tcx.hir().get_parent_item(hir_id); | |
575 | let containing_item = self.tcx.hir().expect_item(parent_hir_id); | |
576 | // We can't link to trait impl's consts. | |
577 | let err = "associated constant in trait implementation block"; | |
578 | match containing_item.kind { | |
5869c6ff | 579 | ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) => Some(err), |
fc512014 XL |
580 | _ => None, |
581 | } | |
582 | } | |
136023e0 XL |
583 | // we check the validity of params elsewhere |
584 | Target::Param => return false, | |
fc512014 XL |
585 | _ => None, |
586 | } { | |
6a06907d | 587 | return err_fn(meta.span(), &format!("isn't allowed on {}", err)); |
fc512014 | 588 | } |
5869c6ff XL |
589 | let item_name = self.tcx.hir().name(hir_id); |
590 | if &*item_name.as_str() == doc_alias { | |
6a06907d XL |
591 | return err_fn(meta.span(), "is the same as the item's name"); |
592 | } | |
c295e0f8 XL |
593 | let span = meta.span(); |
594 | if let Err(entry) = aliases.try_insert(doc_alias.to_owned(), span) { | |
595 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, span, |lint| { | |
596 | lint.build("doc alias is duplicated") | |
597 | .span_label(*entry.entry.get(), "first defined here") | |
598 | .emit(); | |
599 | }); | |
600 | } | |
6a06907d XL |
601 | true |
602 | } | |
603 | ||
c295e0f8 XL |
604 | fn check_doc_alias( |
605 | &self, | |
606 | meta: &NestedMetaItem, | |
607 | hir_id: HirId, | |
608 | target: Target, | |
609 | aliases: &mut FxHashMap<String, Span>, | |
610 | ) -> bool { | |
6a06907d XL |
611 | if let Some(values) = meta.meta_item_list() { |
612 | let mut errors = 0; | |
613 | for v in values { | |
614 | match v.literal() { | |
615 | Some(l) => match l.kind { | |
616 | LitKind::Str(s, _) => { | |
c295e0f8 XL |
617 | if !self.check_doc_alias_value( |
618 | v, | |
619 | &s.as_str(), | |
620 | hir_id, | |
621 | target, | |
622 | true, | |
623 | aliases, | |
624 | ) { | |
6a06907d XL |
625 | errors += 1; |
626 | } | |
627 | } | |
628 | _ => { | |
629 | self.tcx | |
630 | .sess | |
631 | .struct_span_err( | |
632 | v.span(), | |
633 | "`#[doc(alias(\"a\"))]` expects string literals", | |
634 | ) | |
635 | .emit(); | |
636 | errors += 1; | |
637 | } | |
638 | }, | |
639 | None => { | |
640 | self.tcx | |
641 | .sess | |
642 | .struct_span_err( | |
643 | v.span(), | |
644 | "`#[doc(alias(\"a\"))]` expects string literals", | |
645 | ) | |
646 | .emit(); | |
647 | errors += 1; | |
648 | } | |
649 | } | |
650 | } | |
651 | errors == 0 | |
652 | } else if let Some(doc_alias) = meta.value_str().map(|s| s.to_string()) { | |
c295e0f8 | 653 | self.check_doc_alias_value(meta, &doc_alias, hir_id, target, false, aliases) |
6a06907d | 654 | } else { |
5869c6ff XL |
655 | self.tcx |
656 | .sess | |
657 | .struct_span_err( | |
658 | meta.span(), | |
6a06907d XL |
659 | "doc alias attribute expects a string `#[doc(alias = \"a\")]` or a list of \ |
660 | strings `#[doc(alias(\"a\", \"b\"))]`", | |
5869c6ff XL |
661 | ) |
662 | .emit(); | |
6a06907d | 663 | false |
5869c6ff | 664 | } |
fc512014 XL |
665 | } |
666 | ||
667 | fn check_doc_keyword(&self, meta: &NestedMetaItem, hir_id: HirId) -> bool { | |
668 | let doc_keyword = meta.value_str().map(|s| s.to_string()).unwrap_or_else(String::new); | |
669 | if doc_keyword.is_empty() { | |
670 | self.doc_attr_str_error(meta, "keyword"); | |
671 | return false; | |
672 | } | |
136023e0 XL |
673 | match self.tcx.hir().find(hir_id).and_then(|node| match node { |
674 | hir::Node::Item(item) => Some(&item.kind), | |
675 | _ => None, | |
676 | }) { | |
677 | Some(ItemKind::Mod(ref module)) => { | |
fc512014 XL |
678 | if !module.item_ids.is_empty() { |
679 | self.tcx | |
680 | .sess | |
681 | .struct_span_err( | |
682 | meta.span(), | |
683 | "`#[doc(keyword = \"...\")]` can only be used on empty modules", | |
684 | ) | |
685 | .emit(); | |
686 | return false; | |
687 | } | |
688 | } | |
689 | _ => { | |
690 | self.tcx | |
691 | .sess | |
692 | .struct_span_err( | |
693 | meta.span(), | |
694 | "`#[doc(keyword = \"...\")]` can only be used on modules", | |
695 | ) | |
696 | .emit(); | |
697 | return false; | |
698 | } | |
699 | } | |
700 | if !rustc_lexer::is_ident(&doc_keyword) { | |
701 | self.tcx | |
702 | .sess | |
703 | .struct_span_err( | |
704 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
705 | &format!("`{}` is not a valid identifier", doc_keyword), | |
706 | ) | |
707 | .emit(); | |
708 | return false; | |
709 | } | |
710 | true | |
711 | } | |
712 | ||
17df50a5 XL |
713 | /// Checks `#[doc(inline)]`/`#[doc(no_inline)]` attributes. Returns `true` if valid. |
714 | /// | |
715 | /// A doc inlining attribute is invalid if it is applied to a non-`use` item, or | |
716 | /// if there are conflicting attributes for one item. | |
717 | /// | |
718 | /// `specified_inline` is used to keep track of whether we have | |
719 | /// already seen an inlining attribute for this item. | |
720 | /// If so, `specified_inline` holds the value and the span of | |
721 | /// the first `inline`/`no_inline` attribute. | |
722 | fn check_doc_inline( | |
723 | &self, | |
724 | attr: &Attribute, | |
725 | meta: &NestedMetaItem, | |
726 | hir_id: HirId, | |
727 | target: Target, | |
728 | specified_inline: &mut Option<(bool, Span)>, | |
729 | ) -> bool { | |
730 | if target == Target::Use || target == Target::ExternCrate { | |
731 | let do_inline = meta.name_or_empty() == sym::inline; | |
732 | if let Some((prev_inline, prev_span)) = *specified_inline { | |
733 | if do_inline != prev_inline { | |
734 | let mut spans = MultiSpan::from_spans(vec![prev_span, meta.span()]); | |
735 | spans.push_span_label(prev_span, String::from("this attribute...")); | |
736 | spans.push_span_label( | |
737 | meta.span(), | |
738 | String::from("...conflicts with this attribute"), | |
739 | ); | |
740 | self.tcx | |
741 | .sess | |
742 | .struct_span_err(spans, "conflicting doc inlining attributes") | |
743 | .help("remove one of the conflicting attributes") | |
744 | .emit(); | |
745 | return false; | |
746 | } | |
747 | true | |
748 | } else { | |
749 | *specified_inline = Some((do_inline, meta.span())); | |
750 | true | |
751 | } | |
752 | } else { | |
753 | self.tcx.struct_span_lint_hir( | |
754 | INVALID_DOC_ATTRIBUTES, | |
755 | hir_id, | |
756 | meta.span(), | |
757 | |lint| { | |
758 | let mut err = lint.build( | |
759 | "this attribute can only be applied to a `use` item", | |
760 | ); | |
761 | err.span_label(meta.span(), "only applicable on `use` items"); | |
762 | if attr.style == AttrStyle::Outer { | |
763 | err.span_label( | |
764 | self.tcx.hir().span(hir_id), | |
765 | "not a `use` item", | |
766 | ); | |
767 | } | |
768 | err.note("read https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#docno_inlinedocinline for more information") | |
769 | .emit(); | |
770 | }, | |
771 | ); | |
772 | false | |
773 | } | |
774 | } | |
775 | ||
776 | /// Checks that an attribute is *not* used at the crate level. Returns `true` if valid. | |
777 | fn check_attr_not_crate_level( | |
fc512014 XL |
778 | &self, |
779 | meta: &NestedMetaItem, | |
780 | hir_id: HirId, | |
781 | attr_name: &str, | |
782 | ) -> bool { | |
783 | if CRATE_HIR_ID == hir_id { | |
784 | self.tcx | |
785 | .sess | |
786 | .struct_span_err( | |
787 | meta.span(), | |
788 | &format!( | |
6a06907d | 789 | "`#![doc({} = \"...\")]` isn't allowed as a crate-level attribute", |
fc512014 XL |
790 | attr_name, |
791 | ), | |
792 | ) | |
793 | .emit(); | |
794 | return false; | |
795 | } | |
796 | true | |
797 | } | |
798 | ||
17df50a5 XL |
799 | /// Checks that an attribute is used at the crate level. Returns `true` if valid. |
800 | fn check_attr_crate_level( | |
801 | &self, | |
802 | attr: &Attribute, | |
803 | meta: &NestedMetaItem, | |
804 | hir_id: HirId, | |
805 | ) -> bool { | |
806 | if hir_id != CRATE_HIR_ID { | |
807 | self.tcx.struct_span_lint_hir( | |
808 | INVALID_DOC_ATTRIBUTES, | |
809 | hir_id, | |
810 | meta.span(), | |
811 | |lint| { | |
812 | let mut err = lint.build( | |
813 | "this attribute can only be applied at the crate level", | |
814 | ); | |
815 | if attr.style == AttrStyle::Outer && self.tcx.hir().get_parent_item(hir_id) == CRATE_HIR_ID { | |
816 | if let Ok(mut src) = | |
817 | self.tcx.sess.source_map().span_to_snippet(attr.span) | |
818 | { | |
819 | src.insert(1, '!'); | |
820 | err.span_suggestion_verbose( | |
821 | attr.span, | |
822 | "to apply to the crate, use an inner attribute", | |
823 | src, | |
824 | Applicability::MaybeIncorrect, | |
825 | ); | |
826 | } else { | |
827 | err.span_help( | |
828 | attr.span, | |
829 | "to apply to the crate, use an inner attribute", | |
830 | ); | |
831 | } | |
832 | } | |
833 | err.note("read https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#at-the-crate-level for more information") | |
834 | .emit(); | |
835 | }, | |
836 | ); | |
837 | return false; | |
838 | } | |
839 | true | |
840 | } | |
841 | ||
94222f64 XL |
842 | /// Checks that `doc(test(...))` attribute contains only valid attributes. Returns `true` if |
843 | /// valid. | |
844 | fn check_test_attr(&self, meta: &NestedMetaItem, hir_id: HirId) -> bool { | |
845 | let mut is_valid = true; | |
846 | if let Some(metas) = meta.meta_item_list() { | |
847 | for i_meta in metas { | |
848 | match i_meta.name_or_empty() { | |
849 | sym::attr | sym::no_crate_inject => {} | |
850 | _ => { | |
851 | self.tcx.struct_span_lint_hir( | |
852 | INVALID_DOC_ATTRIBUTES, | |
853 | hir_id, | |
854 | i_meta.span(), | |
855 | |lint| { | |
856 | lint.build(&format!( | |
857 | "unknown `doc(test)` attribute `{}`", | |
858 | rustc_ast_pretty::pprust::path_to_string( | |
859 | &i_meta.meta_item().unwrap().path | |
860 | ), | |
861 | )) | |
862 | .emit(); | |
863 | }, | |
864 | ); | |
865 | is_valid = false; | |
866 | } | |
867 | } | |
868 | } | |
869 | } else { | |
870 | self.tcx.struct_span_lint_hir(INVALID_DOC_ATTRIBUTES, hir_id, meta.span(), |lint| { | |
871 | lint.build("`#[doc(test(...)]` takes a list of attributes").emit(); | |
872 | }); | |
873 | is_valid = false; | |
874 | } | |
875 | is_valid | |
876 | } | |
877 | ||
17df50a5 XL |
878 | /// Runs various checks on `#[doc]` attributes. Returns `true` if valid. |
879 | /// | |
880 | /// `specified_inline` should be initialized to `None` and kept for the scope | |
881 | /// of one item. Read the documentation of [`check_doc_inline`] for more information. | |
882 | /// | |
883 | /// [`check_doc_inline`]: Self::check_doc_inline | |
884 | fn check_doc_attrs( | |
885 | &self, | |
886 | attr: &Attribute, | |
887 | hir_id: HirId, | |
888 | target: Target, | |
889 | specified_inline: &mut Option<(bool, Span)>, | |
c295e0f8 | 890 | aliases: &mut FxHashMap<String, Span>, |
17df50a5 | 891 | ) -> bool { |
6a06907d XL |
892 | let mut is_valid = true; |
893 | ||
894 | if let Some(list) = attr.meta().and_then(|mi| mi.meta_item_list().map(|l| l.to_vec())) { | |
17df50a5 | 895 | for meta in &list { |
6a06907d XL |
896 | if let Some(i_meta) = meta.meta_item() { |
897 | match i_meta.name_or_empty() { | |
898 | sym::alias | |
17df50a5 | 899 | if !self.check_attr_not_crate_level(&meta, hir_id, "alias") |
c295e0f8 | 900 | || !self.check_doc_alias(&meta, hir_id, target, aliases) => |
3dfed10e | 901 | { |
6a06907d | 902 | is_valid = false |
29967ef6 | 903 | } |
6a06907d XL |
904 | |
905 | sym::keyword | |
17df50a5 | 906 | if !self.check_attr_not_crate_level(&meta, hir_id, "keyword") |
6a06907d | 907 | || !self.check_doc_keyword(&meta, hir_id) => |
fc512014 | 908 | { |
6a06907d XL |
909 | is_valid = false |
910 | } | |
911 | ||
17df50a5 XL |
912 | sym::html_favicon_url |
913 | | sym::html_logo_url | |
914 | | sym::html_playground_url | |
915 | | sym::issue_tracker_base_url | |
916 | | sym::html_root_url | |
917 | | sym::html_no_source | |
918 | | sym::test | |
919 | if !self.check_attr_crate_level(&attr, &meta, hir_id) => | |
920 | { | |
921 | is_valid = false; | |
922 | } | |
923 | ||
924 | sym::inline | sym::no_inline | |
925 | if !self.check_doc_inline( | |
926 | &attr, | |
927 | &meta, | |
6a06907d | 928 | hir_id, |
17df50a5 XL |
929 | target, |
930 | specified_inline, | |
931 | ) => | |
932 | { | |
6a06907d XL |
933 | is_valid = false; |
934 | } | |
935 | ||
936 | // no_default_passes: deprecated | |
937 | // passes: deprecated | |
938 | // plugins: removed, but rustdoc warns about it itself | |
939 | sym::alias | |
940 | | sym::cfg | |
c295e0f8 | 941 | | sym::cfg_hide |
6a06907d XL |
942 | | sym::hidden |
943 | | sym::html_favicon_url | |
944 | | sym::html_logo_url | |
945 | | sym::html_no_source | |
946 | | sym::html_playground_url | |
947 | | sym::html_root_url | |
6a06907d XL |
948 | | sym::inline |
949 | | sym::issue_tracker_base_url | |
950 | | sym::keyword | |
951 | | sym::masked | |
952 | | sym::no_default_passes | |
953 | | sym::no_inline | |
cdc7bbd5 | 954 | | sym::notable_trait |
6a06907d | 955 | | sym::passes |
94222f64 XL |
956 | | sym::plugins => {} |
957 | ||
958 | sym::test => { | |
959 | if !self.check_test_attr(&meta, hir_id) { | |
960 | is_valid = false; | |
961 | } | |
962 | } | |
963 | ||
964 | sym::primitive => { | |
965 | if !self.tcx.features().doc_primitive { | |
966 | self.tcx.struct_span_lint_hir( | |
967 | INVALID_DOC_ATTRIBUTES, | |
968 | hir_id, | |
969 | i_meta.span, | |
970 | |lint| { | |
971 | let mut diag = lint.build( | |
972 | "`doc(primitive)` should never have been stable", | |
973 | ); | |
974 | diag.emit(); | |
975 | }, | |
976 | ); | |
977 | } | |
978 | } | |
6a06907d XL |
979 | |
980 | _ => { | |
981 | self.tcx.struct_span_lint_hir( | |
982 | INVALID_DOC_ATTRIBUTES, | |
983 | hir_id, | |
984 | i_meta.span, | |
985 | |lint| { | |
cdc7bbd5 | 986 | let mut diag = lint.build(&format!( |
6a06907d XL |
987 | "unknown `doc` attribute `{}`", |
988 | rustc_ast_pretty::pprust::path_to_string(&i_meta.path), | |
cdc7bbd5 XL |
989 | )); |
990 | if i_meta.has_name(sym::spotlight) { | |
991 | diag.note( | |
992 | "`doc(spotlight)` was renamed to `doc(notable_trait)`", | |
993 | ); | |
994 | diag.span_suggestion_short( | |
995 | i_meta.span, | |
996 | "use `notable_trait` instead", | |
997 | String::from("notable_trait"), | |
998 | Applicability::MachineApplicable, | |
999 | ); | |
1000 | diag.note("`doc(spotlight)` is now a no-op"); | |
1001 | } | |
17df50a5 XL |
1002 | if i_meta.has_name(sym::include) { |
1003 | if let Some(value) = i_meta.value_str() { | |
1004 | // if there are multiple attributes, the suggestion would suggest deleting all of them, which is incorrect | |
1005 | let applicability = if list.len() == 1 { | |
1006 | Applicability::MachineApplicable | |
1007 | } else { | |
1008 | Applicability::MaybeIncorrect | |
1009 | }; | |
1010 | let inner = if attr.style == AttrStyle::Inner { | |
1011 | "!" | |
1012 | } else { | |
1013 | "" | |
1014 | }; | |
1015 | diag.span_suggestion( | |
1016 | attr.meta().unwrap().span, | |
1017 | "use `doc = include_str!` instead", | |
1018 | format!( | |
1019 | "#{}[doc = include_str!(\"{}\")]", | |
1020 | inner, value | |
1021 | ), | |
1022 | applicability, | |
1023 | ); | |
1024 | } | |
1025 | } | |
cdc7bbd5 | 1026 | diag.emit(); |
6a06907d XL |
1027 | }, |
1028 | ); | |
1029 | is_valid = false; | |
29967ef6 | 1030 | } |
3dfed10e | 1031 | } |
6a06907d XL |
1032 | } else { |
1033 | self.tcx.struct_span_lint_hir( | |
1034 | INVALID_DOC_ATTRIBUTES, | |
1035 | hir_id, | |
1036 | meta.span(), | |
1037 | |lint| { | |
94222f64 | 1038 | lint.build(&"invalid `doc` attribute").emit(); |
6a06907d XL |
1039 | }, |
1040 | ); | |
1041 | is_valid = false; | |
3dfed10e XL |
1042 | } |
1043 | } | |
1044 | } | |
6a06907d XL |
1045 | |
1046 | is_valid | |
3dfed10e XL |
1047 | } |
1048 | ||
c295e0f8 XL |
1049 | /// Checks if `#[must_not_suspend]` is applied to a function. Returns `true` if valid. |
1050 | fn check_must_not_suspend(&self, attr: &Attribute, span: &Span, target: Target) -> bool { | |
1051 | match target { | |
1052 | Target::Struct | Target::Enum | Target::Union | Target::Trait => true, | |
1053 | _ => { | |
1054 | self.tcx | |
1055 | .sess | |
1056 | .struct_span_err(attr.span, "`must_not_suspend` attribute should be applied to a struct, enum, or trait") | |
1057 | .span_label(*span, "is not a struct, enum, or trait") | |
1058 | .emit(); | |
1059 | false | |
1060 | } | |
1061 | } | |
1062 | } | |
1063 | ||
1b1a35ee XL |
1064 | /// Checks if `#[cold]` is applied to a non-function. Returns `true` if valid. |
1065 | fn check_cold(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
1066 | match target { | |
1067 | Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => {} | |
5869c6ff XL |
1068 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
1069 | // `#[cold]` attribute with just a lint, because we previously | |
1070 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1071 | // with crates depending on them, we can't throw an error here. | |
1072 | Target::Field | Target::Arm | Target::MacroDef => { | |
1073 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "cold"); | |
1074 | } | |
1b1a35ee XL |
1075 | _ => { |
1076 | // FIXME: #[cold] was previously allowed on non-functions and some crates used | |
1077 | // this, so only emit a warning. | |
1078 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1079 | lint.build("attribute should be applied to a function") | |
1080 | .warn( | |
1081 | "this was previously accepted by the compiler but is \ | |
1082 | being phased out; it will become a hard error in \ | |
1083 | a future release!", | |
1084 | ) | |
1085 | .span_label(*span, "not a function") | |
1086 | .emit(); | |
1087 | }); | |
1088 | } | |
1089 | } | |
1090 | } | |
1091 | ||
1092 | /// Checks if `#[link_name]` is applied to an item other than a foreign function or static. | |
1093 | fn check_link_name(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
1094 | match target { | |
1095 | Target::ForeignFn | Target::ForeignStatic => {} | |
5869c6ff XL |
1096 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
1097 | // `#[link_name]` attribute with just a lint, because we previously | |
1098 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1099 | // with crates depending on them, we can't throw an error here. | |
1100 | Target::Field | Target::Arm | Target::MacroDef => { | |
1101 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "link_name"); | |
1102 | } | |
1b1a35ee XL |
1103 | _ => { |
1104 | // FIXME: #[cold] was previously allowed on non-functions/statics and some crates | |
1105 | // used this, so only emit a warning. | |
1106 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1107 | let mut diag = | |
1108 | lint.build("attribute should be applied to a foreign function or static"); | |
1109 | diag.warn( | |
1110 | "this was previously accepted by the compiler but is \ | |
1111 | being phased out; it will become a hard error in \ | |
1112 | a future release!", | |
1113 | ); | |
1114 | ||
1115 | // See issue #47725 | |
1116 | if let Target::ForeignMod = target { | |
1117 | if let Some(value) = attr.value_str() { | |
1118 | diag.span_help( | |
1119 | attr.span, | |
1120 | &format!(r#"try `#[link(name = "{}")]` instead"#, value), | |
1121 | ); | |
1122 | } else { | |
1123 | diag.span_help(attr.span, r#"try `#[link(name = "...")]` instead"#); | |
1124 | } | |
1125 | } | |
1126 | ||
1127 | diag.span_label(*span, "not a foreign function or static"); | |
1128 | diag.emit(); | |
1129 | }); | |
1130 | } | |
1131 | } | |
1132 | } | |
1133 | ||
1134 | /// Checks if `#[no_link]` is applied to an `extern crate`. Returns `true` if valid. | |
5869c6ff XL |
1135 | fn check_no_link(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { |
1136 | match target { | |
1137 | Target::ExternCrate => true, | |
1138 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an | |
1139 | // `#[no_link]` attribute with just a lint, because we previously | |
1140 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1141 | // with crates depending on them, we can't throw an error here. | |
1142 | Target::Field | Target::Arm | Target::MacroDef => { | |
1143 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "no_link"); | |
1144 | true | |
1145 | } | |
1146 | _ => { | |
1147 | self.tcx | |
1148 | .sess | |
1149 | .struct_span_err( | |
1150 | attr.span, | |
1151 | "attribute should be applied to an `extern crate` item", | |
1152 | ) | |
1153 | .span_label(*span, "not an `extern crate` item") | |
1154 | .emit(); | |
1155 | false | |
1156 | } | |
1b1a35ee XL |
1157 | } |
1158 | } | |
1159 | ||
94222f64 XL |
1160 | fn is_impl_item(&self, hir_id: HirId) -> bool { |
1161 | matches!(self.tcx.hir().get(hir_id), hir::Node::ImplItem(..)) | |
1162 | } | |
1163 | ||
1b1a35ee | 1164 | /// Checks if `#[export_name]` is applied to a function or static. Returns `true` if valid. |
5869c6ff XL |
1165 | fn check_export_name( |
1166 | &self, | |
1167 | hir_id: HirId, | |
1168 | attr: &Attribute, | |
1169 | span: &Span, | |
1170 | target: Target, | |
1171 | ) -> bool { | |
1b1a35ee | 1172 | match target { |
94222f64 XL |
1173 | Target::Static | Target::Fn => true, |
1174 | Target::Method(..) if self.is_impl_item(hir_id) => true, | |
5869c6ff XL |
1175 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
1176 | // `#[export_name]` attribute with just a lint, because we previously | |
1177 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1178 | // with crates depending on them, we can't throw an error here. | |
1179 | Target::Field | Target::Arm | Target::MacroDef => { | |
1180 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "export_name"); | |
1181 | true | |
1182 | } | |
1b1a35ee XL |
1183 | _ => { |
1184 | self.tcx | |
1185 | .sess | |
1186 | .struct_span_err( | |
1187 | attr.span, | |
94222f64 | 1188 | "attribute should be applied to a free function, impl method or static", |
1b1a35ee | 1189 | ) |
94222f64 | 1190 | .span_label(*span, "not a free function, impl method or static") |
1b1a35ee XL |
1191 | .emit(); |
1192 | false | |
1193 | } | |
1194 | } | |
1195 | } | |
1196 | ||
6a06907d XL |
1197 | fn check_rustc_layout_scalar_valid_range( |
1198 | &self, | |
1199 | attr: &Attribute, | |
1200 | span: &Span, | |
1201 | target: Target, | |
1202 | ) -> bool { | |
1203 | if target != Target::Struct { | |
1204 | self.tcx | |
1205 | .sess | |
1206 | .struct_span_err(attr.span, "attribute should be applied to a struct") | |
1207 | .span_label(*span, "not a struct") | |
1208 | .emit(); | |
1209 | return false; | |
1210 | } | |
1211 | ||
1212 | let list = match attr.meta_item_list() { | |
1213 | None => return false, | |
1214 | Some(it) => it, | |
1215 | }; | |
1216 | ||
1217 | if matches!(&list[..], &[NestedMetaItem::Literal(Lit { kind: LitKind::Int(..), .. })]) { | |
1218 | true | |
1219 | } else { | |
1220 | self.tcx | |
1221 | .sess | |
1222 | .struct_span_err(attr.span, "expected exactly one integer literal argument") | |
1223 | .emit(); | |
1224 | false | |
1225 | } | |
1226 | } | |
1227 | ||
1228 | /// Checks if `#[rustc_legacy_const_generics]` is applied to a function and has a valid argument. | |
1229 | fn check_rustc_legacy_const_generics( | |
1230 | &self, | |
1231 | attr: &Attribute, | |
1232 | span: &Span, | |
1233 | target: Target, | |
1234 | item: Option<ItemLike<'_>>, | |
1235 | ) -> bool { | |
1236 | let is_function = matches!(target, Target::Fn | Target::Method(..)); | |
1237 | if !is_function { | |
1238 | self.tcx | |
1239 | .sess | |
1240 | .struct_span_err(attr.span, "attribute should be applied to a function") | |
1241 | .span_label(*span, "not a function") | |
1242 | .emit(); | |
1243 | return false; | |
1244 | } | |
1245 | ||
1246 | let list = match attr.meta_item_list() { | |
1247 | // The attribute form is validated on AST. | |
1248 | None => return false, | |
1249 | Some(it) => it, | |
1250 | }; | |
1251 | ||
1252 | let (decl, generics) = match item { | |
1253 | Some(ItemLike::Item(Item { | |
1254 | kind: ItemKind::Fn(FnSig { decl, .. }, generics, _), | |
1255 | .. | |
1256 | })) => (decl, generics), | |
1257 | _ => bug!("should be a function item"), | |
1258 | }; | |
1259 | ||
1260 | for param in generics.params { | |
1261 | match param.kind { | |
1262 | hir::GenericParamKind::Const { .. } => {} | |
1263 | _ => { | |
1264 | self.tcx | |
1265 | .sess | |
1266 | .struct_span_err( | |
1267 | attr.span, | |
1268 | "#[rustc_legacy_const_generics] functions must \ | |
1269 | only have const generics", | |
1270 | ) | |
1271 | .span_label(param.span, "non-const generic parameter") | |
1272 | .emit(); | |
1273 | return false; | |
1274 | } | |
1275 | } | |
1276 | } | |
1277 | ||
1278 | if list.len() != generics.params.len() { | |
1279 | self.tcx | |
1280 | .sess | |
1281 | .struct_span_err( | |
1282 | attr.span, | |
1283 | "#[rustc_legacy_const_generics] must have one index for each generic parameter", | |
1284 | ) | |
1285 | .span_label(generics.span, "generic parameters") | |
1286 | .emit(); | |
1287 | return false; | |
1288 | } | |
1289 | ||
1290 | let arg_count = decl.inputs.len() as u128 + generics.params.len() as u128; | |
1291 | let mut invalid_args = vec![]; | |
1292 | for meta in list { | |
1293 | if let Some(LitKind::Int(val, _)) = meta.literal().map(|lit| &lit.kind) { | |
1294 | if *val >= arg_count { | |
1295 | let span = meta.span(); | |
1296 | self.tcx | |
1297 | .sess | |
1298 | .struct_span_err(span, "index exceeds number of arguments") | |
1299 | .span_label( | |
1300 | span, | |
1301 | format!( | |
1302 | "there {} only {} argument{}", | |
1303 | if arg_count != 1 { "are" } else { "is" }, | |
1304 | arg_count, | |
1305 | pluralize!(arg_count) | |
1306 | ), | |
1307 | ) | |
1308 | .emit(); | |
1309 | return false; | |
1310 | } | |
1311 | } else { | |
1312 | invalid_args.push(meta.span()); | |
1313 | } | |
1314 | } | |
1315 | ||
1316 | if !invalid_args.is_empty() { | |
1317 | self.tcx | |
1318 | .sess | |
1319 | .struct_span_err(invalid_args, "arguments should be non-negative integers") | |
1320 | .emit(); | |
1321 | false | |
1322 | } else { | |
1323 | true | |
1324 | } | |
1325 | } | |
1326 | ||
cdc7bbd5 XL |
1327 | /// Checks that the dep-graph debugging attributes are only present when the query-dep-graph |
1328 | /// option is passed to the compiler. | |
1329 | fn check_rustc_dirty_clean(&self, attr: &Attribute) -> bool { | |
1330 | if self.tcx.sess.opts.debugging_opts.query_dep_graph { | |
1331 | true | |
1332 | } else { | |
1333 | self.tcx | |
1334 | .sess | |
1335 | .struct_span_err(attr.span, "attribute requires -Z query-dep-graph to be enabled") | |
1336 | .emit(); | |
1337 | false | |
1338 | } | |
1339 | } | |
1340 | ||
1b1a35ee XL |
1341 | /// Checks if `#[link_section]` is applied to a function or static. |
1342 | fn check_link_section(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
1343 | match target { | |
1344 | Target::Static | Target::Fn | Target::Method(..) => {} | |
5869c6ff XL |
1345 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
1346 | // `#[link_section]` attribute with just a lint, because we previously | |
1347 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1348 | // with crates depending on them, we can't throw an error here. | |
1349 | Target::Field | Target::Arm | Target::MacroDef => { | |
1350 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "link_section"); | |
1351 | } | |
1b1a35ee XL |
1352 | _ => { |
1353 | // FIXME: #[link_section] was previously allowed on non-functions/statics and some | |
1354 | // crates used this, so only emit a warning. | |
1355 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1356 | lint.build("attribute should be applied to a function or static") | |
1357 | .warn( | |
1358 | "this was previously accepted by the compiler but is \ | |
1359 | being phased out; it will become a hard error in \ | |
1360 | a future release!", | |
1361 | ) | |
1362 | .span_label(*span, "not a function or static") | |
1363 | .emit(); | |
1364 | }); | |
1365 | } | |
1366 | } | |
1367 | } | |
1368 | ||
1369 | /// Checks if `#[no_mangle]` is applied to a function or static. | |
1370 | fn check_no_mangle(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
1371 | match target { | |
94222f64 XL |
1372 | Target::Static | Target::Fn => {} |
1373 | Target::Method(..) if self.is_impl_item(hir_id) => {} | |
5869c6ff XL |
1374 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
1375 | // `#[no_mangle]` attribute with just a lint, because we previously | |
1376 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1377 | // with crates depending on them, we can't throw an error here. | |
1378 | Target::Field | Target::Arm | Target::MacroDef => { | |
1379 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "no_mangle"); | |
1380 | } | |
94222f64 XL |
1381 | // FIXME: #[no_mangle] was previously allowed on non-functions/statics, this should be an error |
1382 | // The error should specify that the item that is wrong is specifically a *foreign* fn/static | |
1383 | // otherwise the error seems odd | |
1384 | Target::ForeignFn | Target::ForeignStatic => { | |
1385 | let foreign_item_kind = match target { | |
1386 | Target::ForeignFn => "function", | |
1387 | Target::ForeignStatic => "static", | |
1388 | _ => unreachable!(), | |
1389 | }; | |
1390 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1391 | lint.build(&format!( | |
1392 | "`#[no_mangle]` has no effect on a foreign {}", | |
1393 | foreign_item_kind | |
1394 | )) | |
1395 | .warn( | |
1396 | "this was previously accepted by the compiler but is \ | |
1397 | being phased out; it will become a hard error in \ | |
1398 | a future release!", | |
1399 | ) | |
1400 | .span_label(*span, format!("foreign {}", foreign_item_kind)) | |
1401 | .note("symbol names in extern blocks are not mangled") | |
1402 | .span_suggestion( | |
1403 | attr.span, | |
1404 | "remove this attribute", | |
1405 | String::new(), | |
1406 | Applicability::MachineApplicable, | |
1407 | ) | |
1408 | .emit(); | |
1409 | }); | |
1410 | } | |
1b1a35ee XL |
1411 | _ => { |
1412 | // FIXME: #[no_mangle] was previously allowed on non-functions/statics and some | |
1413 | // crates used this, so only emit a warning. | |
1414 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
94222f64 XL |
1415 | lint.build( |
1416 | "attribute should be applied to a free function, impl method or static", | |
1417 | ) | |
1418 | .warn( | |
1419 | "this was previously accepted by the compiler but is \ | |
1420 | being phased out; it will become a hard error in \ | |
1421 | a future release!", | |
1422 | ) | |
1423 | .span_label(*span, "not a free function, impl method or static") | |
1424 | .emit(); | |
1b1a35ee XL |
1425 | }); |
1426 | } | |
1427 | } | |
1428 | } | |
1429 | ||
9fa01778 | 1430 | /// Checks if the `#[repr]` attributes on `item` are valid. |
e74abb32 XL |
1431 | fn check_repr( |
1432 | &self, | |
dfeec247 | 1433 | attrs: &'hir [Attribute], |
e74abb32 XL |
1434 | span: &Span, |
1435 | target: Target, | |
1b1a35ee | 1436 | item: Option<ItemLike<'_>>, |
dfeec247 | 1437 | hir_id: HirId, |
e74abb32 | 1438 | ) { |
2c00a5a8 XL |
1439 | // Extract the names of all repr hints, e.g., [foo, bar, align] for: |
1440 | // ``` | |
1441 | // #[repr(foo)] | |
1442 | // #[repr(bar, align(8))] | |
1443 | // ``` | |
e74abb32 | 1444 | let hints: Vec<_> = attrs |
2c00a5a8 | 1445 | .iter() |
cdc7bbd5 | 1446 | .filter(|attr| attr.has_name(sym::repr)) |
2c00a5a8 | 1447 | .filter_map(|attr| attr.meta_item_list()) |
b7449926 | 1448 | .flatten() |
2c00a5a8 | 1449 | .collect(); |
9e0c209e | 1450 | |
ff7c6d11 XL |
1451 | let mut int_reprs = 0; |
1452 | let mut is_c = false; | |
1453 | let mut is_simd = false; | |
2c00a5a8 XL |
1454 | let mut is_transparent = false; |
1455 | ||
1456 | for hint in &hints { | |
136023e0 XL |
1457 | if !hint.is_meta_item() { |
1458 | struct_span_err!( | |
1459 | self.tcx.sess, | |
1460 | hint.span(), | |
1461 | E0565, | |
1462 | "meta item in `repr` must be an identifier" | |
1463 | ) | |
1464 | .emit(); | |
1465 | continue; | |
1466 | } | |
1467 | ||
48663c56 | 1468 | let (article, allowed_targets) = match hint.name_or_empty() { |
136023e0 XL |
1469 | sym::C => { |
1470 | is_c = true; | |
dc9dc135 XL |
1471 | match target { |
1472 | Target::Struct | Target::Union | Target::Enum => continue, | |
1473 | _ => ("a", "struct, enum, or union"), | |
9e0c209e SL |
1474 | } |
1475 | } | |
136023e0 XL |
1476 | sym::align => { |
1477 | if let (Target::Fn, true) = (target, !self.tcx.features().fn_align) { | |
1478 | feature_err( | |
1479 | &self.tcx.sess.parse_sess, | |
1480 | sym::fn_align, | |
1481 | hint.span(), | |
1482 | "`repr(align)` attributes on functions are unstable", | |
1483 | ) | |
1484 | .emit(); | |
1485 | } | |
1486 | ||
1487 | match target { | |
1488 | Target::Struct | Target::Union | Target::Enum | Target::Fn => continue, | |
1489 | _ => ("a", "struct, enum, function, or union"), | |
1490 | } | |
1491 | } | |
48663c56 | 1492 | sym::packed => { |
dfeec247 XL |
1493 | if target != Target::Struct && target != Target::Union { |
1494 | ("a", "struct or union") | |
92a42be0 | 1495 | } else { |
dfeec247 | 1496 | continue; |
b039eaaf SL |
1497 | } |
1498 | } | |
48663c56 | 1499 | sym::simd => { |
ff7c6d11 | 1500 | is_simd = true; |
1b1a35ee XL |
1501 | if target != Target::Struct { |
1502 | ("a", "struct") | |
1503 | } else { | |
1504 | continue; | |
1505 | } | |
b039eaaf | 1506 | } |
48663c56 | 1507 | sym::transparent => { |
2c00a5a8 | 1508 | is_transparent = true; |
dc9dc135 XL |
1509 | match target { |
1510 | Target::Struct | Target::Union | Target::Enum => continue, | |
1511 | _ => ("a", "struct, enum, or union"), | |
cc61c64b XL |
1512 | } |
1513 | } | |
74b04a01 XL |
1514 | sym::no_niche => { |
1515 | if !self.tcx.features().enabled(sym::no_niche) { | |
1516 | feature_err( | |
1517 | &self.tcx.sess.parse_sess, | |
1518 | sym::no_niche, | |
1519 | hint.span(), | |
1520 | "the attribute `repr(no_niche)` is currently unstable", | |
1521 | ) | |
1522 | .emit(); | |
1523 | } | |
1524 | match target { | |
1525 | Target::Struct | Target::Enum => continue, | |
1526 | _ => ("a", "struct or enum"), | |
1527 | } | |
1528 | } | |
dfeec247 XL |
1529 | sym::i8 |
1530 | | sym::u8 | |
1531 | | sym::i16 | |
1532 | | sym::u16 | |
1533 | | sym::i32 | |
1534 | | sym::u32 | |
1535 | | sym::i64 | |
1536 | | sym::u64 | |
f035d41b XL |
1537 | | sym::i128 |
1538 | | sym::u128 | |
dfeec247 XL |
1539 | | sym::isize |
1540 | | sym::usize => { | |
ff7c6d11 | 1541 | int_reprs += 1; |
1b1a35ee XL |
1542 | if target != Target::Enum { |
1543 | ("an", "enum") | |
1544 | } else { | |
1545 | continue; | |
1546 | } | |
b039eaaf | 1547 | } |
136023e0 XL |
1548 | _ => { |
1549 | struct_span_err!( | |
1550 | self.tcx.sess, | |
1551 | hint.span(), | |
1552 | E0552, | |
1553 | "unrecognized representation hint" | |
1554 | ) | |
1555 | .emit(); | |
1556 | ||
1557 | continue; | |
1558 | } | |
92a42be0 | 1559 | }; |
29967ef6 XL |
1560 | |
1561 | struct_span_err!( | |
1562 | self.tcx.sess, | |
532ac7d7 | 1563 | hint.span(), |
29967ef6 XL |
1564 | E0517, |
1565 | "{}", | |
1566 | &format!("attribute should be applied to {} {}", article, allowed_targets) | |
0531ce1d | 1567 | ) |
29967ef6 XL |
1568 | .span_label(*span, &format!("not {} {}", article, allowed_targets)) |
1569 | .emit(); | |
9e0c209e | 1570 | } |
ff7c6d11 | 1571 | |
2c00a5a8 XL |
1572 | // Just point at all repr hints if there are any incompatibilities. |
1573 | // This is not ideal, but tracking precisely which ones are at fault is a huge hassle. | |
532ac7d7 | 1574 | let hint_spans = hints.iter().map(|hint| hint.span()); |
2c00a5a8 | 1575 | |
74b04a01 XL |
1576 | // Error on repr(transparent, <anything else apart from no_niche>). |
1577 | let non_no_niche = |hint: &&NestedMetaItem| hint.name_or_empty() != sym::no_niche; | |
1578 | let non_no_niche_count = hints.iter().filter(non_no_niche).count(); | |
1579 | if is_transparent && non_no_niche_count > 1 { | |
2c00a5a8 | 1580 | let hint_spans: Vec<_> = hint_spans.clone().collect(); |
dfeec247 XL |
1581 | struct_span_err!( |
1582 | self.tcx.sess, | |
1583 | hint_spans, | |
1584 | E0692, | |
1585 | "transparent {} cannot have other repr hints", | |
1586 | target | |
1587 | ) | |
1588 | .emit(); | |
2c00a5a8 | 1589 | } |
ff7c6d11 XL |
1590 | // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8) |
1591 | if (int_reprs > 1) | |
dfeec247 | 1592 | || (is_simd && is_c) |
1b1a35ee XL |
1593 | || (int_reprs == 1 |
1594 | && is_c | |
1595 | && item.map_or(false, |item| { | |
1596 | if let ItemLike::Item(item) = item { | |
1597 | return is_c_like_enum(item); | |
1598 | } | |
1599 | return false; | |
1600 | })) | |
dfeec247 | 1601 | { |
74b04a01 XL |
1602 | self.tcx.struct_span_lint_hir( |
1603 | CONFLICTING_REPR_HINTS, | |
1604 | hir_id, | |
1605 | hint_spans.collect::<Vec<Span>>(), | |
1606 | |lint| { | |
1607 | lint.build("conflicting representation hints") | |
1608 | .code(rustc_errors::error_code!(E0566)) | |
1609 | .emit(); | |
1610 | }, | |
1611 | ); | |
b039eaaf SL |
1612 | } |
1613 | } | |
0531ce1d | 1614 | |
29967ef6 XL |
1615 | fn check_used(&self, attrs: &'hir [Attribute], target: Target) { |
1616 | for attr in attrs { | |
cdc7bbd5 | 1617 | if attr.has_name(sym::used) && target != Target::Static { |
29967ef6 XL |
1618 | self.tcx |
1619 | .sess | |
1620 | .span_err(attr.span, "attribute must be applied to a `static` variable"); | |
0531ce1d XL |
1621 | } |
1622 | } | |
1623 | } | |
1624 | ||
29967ef6 XL |
1625 | /// Outputs an error for `#[allow_internal_unstable]` which can only be applied to macros. |
1626 | /// (Allows proc_macro functions) | |
1627 | fn check_allow_internal_unstable( | |
1628 | &self, | |
5869c6ff | 1629 | hir_id: HirId, |
29967ef6 XL |
1630 | attr: &Attribute, |
1631 | span: &Span, | |
1632 | target: Target, | |
1633 | attrs: &[Attribute], | |
1634 | ) -> bool { | |
1635 | debug!("Checking target: {:?}", target); | |
5869c6ff XL |
1636 | match target { |
1637 | Target::Fn => { | |
1638 | for attr in attrs { | |
1639 | if self.tcx.sess.is_proc_macro_attr(attr) { | |
1640 | debug!("Is proc macro attr"); | |
1641 | return true; | |
1642 | } | |
29967ef6 | 1643 | } |
5869c6ff XL |
1644 | debug!("Is not proc macro attr"); |
1645 | false | |
1646 | } | |
1647 | Target::MacroDef => true, | |
1648 | // FIXME(#80564): We permit struct fields and match arms to have an | |
1649 | // `#[allow_internal_unstable]` attribute with just a lint, because we previously | |
1650 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1651 | // with crates depending on them, we can't throw an error here. | |
1652 | Target::Field | Target::Arm => { | |
1653 | self.inline_attr_str_error_without_macro_def( | |
1654 | hir_id, | |
1655 | attr, | |
1656 | "allow_internal_unstable", | |
1657 | ); | |
1658 | true | |
1659 | } | |
1660 | _ => { | |
1661 | self.tcx | |
1662 | .sess | |
1663 | .struct_span_err(attr.span, "attribute should be applied to a macro") | |
1664 | .span_label(*span, "not a macro") | |
1665 | .emit(); | |
1666 | false | |
0531ce1d XL |
1667 | } |
1668 | } | |
1669 | } | |
83c7162d | 1670 | |
29967ef6 XL |
1671 | /// Outputs an error for `#[allow_internal_unstable]` which can only be applied to macros. |
1672 | /// (Allows proc_macro functions) | |
1673 | fn check_rustc_allow_const_fn_unstable( | |
1674 | &self, | |
1675 | hir_id: HirId, | |
1676 | attr: &Attribute, | |
1677 | span: &Span, | |
1678 | target: Target, | |
1679 | ) -> bool { | |
5869c6ff XL |
1680 | match target { |
1681 | Target::Fn | Target::Method(_) | |
1682 | if self.tcx.is_const_fn_raw(self.tcx.hir().local_def_id(hir_id)) => | |
1683 | { | |
1684 | true | |
1685 | } | |
1686 | // FIXME(#80564): We permit struct fields and match arms to have an | |
1687 | // `#[allow_internal_unstable]` attribute with just a lint, because we previously | |
1688 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1689 | // with crates depending on them, we can't throw an error here. | |
1690 | Target::Field | Target::Arm | Target::MacroDef => { | |
1691 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "allow_internal_unstable"); | |
1692 | true | |
1693 | } | |
1694 | _ => { | |
1695 | self.tcx | |
1696 | .sess | |
1697 | .struct_span_err(attr.span, "attribute should be applied to `const fn`") | |
1698 | .span_label(*span, "not a `const fn`") | |
1699 | .emit(); | |
1700 | false | |
83c7162d XL |
1701 | } |
1702 | } | |
1703 | } | |
136023e0 XL |
1704 | |
1705 | /// default_method_body_is_const should only be applied to trait methods with default bodies. | |
1706 | fn check_default_method_body_is_const( | |
1707 | &self, | |
1708 | attr: &Attribute, | |
1709 | span: &Span, | |
1710 | target: Target, | |
1711 | ) -> bool { | |
1712 | match target { | |
1713 | Target::Method(MethodKind::Trait { body: true }) => true, | |
1714 | _ => { | |
1715 | self.tcx | |
1716 | .sess | |
1717 | .struct_span_err( | |
1718 | attr.span, | |
1719 | "attribute should be applied to a trait method with body", | |
1720 | ) | |
1721 | .span_label(*span, "not a trait method or missing a body") | |
1722 | .emit(); | |
1723 | false | |
1724 | } | |
1725 | } | |
1726 | } | |
94222f64 XL |
1727 | |
1728 | fn check_stability_promotable(&self, attr: &Attribute, _span: &Span, target: Target) -> bool { | |
1729 | match target { | |
1730 | Target::Expression => { | |
1731 | self.tcx | |
1732 | .sess | |
1733 | .struct_span_err(attr.span, "attribute cannot be applied to an expression") | |
1734 | .emit(); | |
1735 | false | |
1736 | } | |
1737 | _ => true, | |
1738 | } | |
1739 | } | |
1740 | ||
1741 | fn check_deprecated(&self, hir_id: HirId, attr: &Attribute, _span: &Span, target: Target) { | |
1742 | match target { | |
1743 | Target::Closure | Target::Expression | Target::Statement | Target::Arm => { | |
1744 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1745 | lint.build("attribute is ignored here").emit(); | |
1746 | }); | |
1747 | } | |
1748 | _ => {} | |
1749 | } | |
1750 | } | |
1751 | ||
1752 | fn check_macro_use(&self, hir_id: HirId, attr: &Attribute, target: Target) { | |
1753 | let name = attr.name_or_empty(); | |
1754 | match target { | |
1755 | Target::ExternCrate | Target::Mod => {} | |
1756 | _ => { | |
1757 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1758 | lint.build(&format!( | |
1759 | "`#[{name}]` only has an effect on `extern crate` and modules" | |
1760 | )) | |
1761 | .emit(); | |
1762 | }); | |
1763 | } | |
1764 | } | |
1765 | } | |
1766 | ||
1767 | fn check_macro_export(&self, hir_id: HirId, attr: &Attribute, target: Target) { | |
1768 | if target != Target::MacroDef { | |
1769 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
c295e0f8 | 1770 | lint.build("`#[macro_export]` only has an effect on macro definitions").emit(); |
94222f64 XL |
1771 | }); |
1772 | } | |
1773 | } | |
1774 | ||
1775 | fn check_cfg_attr(&self, hir_id: HirId, attr: &Attribute) { | |
1776 | if let Some((_, attrs)) = rustc_parse::parse_cfg_attr(&attr, &self.tcx.sess.parse_sess) { | |
1777 | if attrs.is_empty() { | |
1778 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1779 | lint.build("`#[cfg_attr]` does not expand to any attributes").emit(); | |
1780 | }); | |
1781 | } | |
1782 | } | |
1783 | } | |
1784 | ||
1785 | fn check_plugin_registrar(&self, hir_id: HirId, attr: &Attribute, target: Target) { | |
1786 | if target != Target::Fn { | |
1787 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1788 | lint.build("`#[plugin_registrar]` only has an effect on functions").emit(); | |
1789 | }); | |
1790 | } | |
1791 | } | |
b039eaaf SL |
1792 | } |
1793 | ||
dc9dc135 | 1794 | impl Visitor<'tcx> for CheckAttrVisitor<'tcx> { |
dfeec247 XL |
1795 | type Map = Map<'tcx>; |
1796 | ||
ba9703b0 XL |
1797 | fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { |
1798 | NestedVisitorMap::OnlyBodies(self.tcx.hir()) | |
2c00a5a8 XL |
1799 | } |
1800 | ||
dfeec247 | 1801 | fn visit_item(&mut self, item: &'tcx Item<'tcx>) { |
94222f64 XL |
1802 | // Historically we've run more checks on non-exported than exported macros, |
1803 | // so this lets us continue to run them while maintaining backwards compatibility. | |
1804 | // In the long run, the checks should be harmonized. | |
1805 | if let ItemKind::Macro(ref macro_def) = item.kind { | |
1806 | let def_id = item.def_id.to_def_id(); | |
1807 | if macro_def.macro_rules && !self.tcx.has_attr(def_id, sym::macro_export) { | |
1808 | check_non_exported_macro_for_invalid_attrs(self.tcx, item); | |
1809 | } | |
1810 | } | |
1811 | ||
b039eaaf | 1812 | let target = Target::from_item(item); |
6a06907d | 1813 | self.check_attributes(item.hir_id(), &item.span, target, Some(ItemLike::Item(item))); |
0531ce1d XL |
1814 | intravisit::walk_item(self, item) |
1815 | } | |
1816 | ||
fc512014 XL |
1817 | fn visit_generic_param(&mut self, generic_param: &'tcx hir::GenericParam<'tcx>) { |
1818 | let target = Target::from_generic_param(generic_param); | |
6a06907d | 1819 | self.check_attributes(generic_param.hir_id, &generic_param.span, target, None); |
fc512014 XL |
1820 | intravisit::walk_generic_param(self, generic_param) |
1821 | } | |
1822 | ||
dfeec247 | 1823 | fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>) { |
e74abb32 | 1824 | let target = Target::from_trait_item(trait_item); |
6a06907d | 1825 | self.check_attributes(trait_item.hir_id(), &trait_item.span, target, None); |
e74abb32 XL |
1826 | intravisit::walk_trait_item(self, trait_item) |
1827 | } | |
1828 | ||
6a06907d XL |
1829 | fn visit_field_def(&mut self, struct_field: &'tcx hir::FieldDef<'tcx>) { |
1830 | self.check_attributes(struct_field.hir_id, &struct_field.span, Target::Field, None); | |
1831 | intravisit::walk_field_def(self, struct_field); | |
5869c6ff XL |
1832 | } |
1833 | ||
1834 | fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) { | |
6a06907d | 1835 | self.check_attributes(arm.hir_id, &arm.span, Target::Arm, None); |
5869c6ff XL |
1836 | intravisit::walk_arm(self, arm); |
1837 | } | |
1838 | ||
1b1a35ee | 1839 | fn visit_foreign_item(&mut self, f_item: &'tcx ForeignItem<'tcx>) { |
e74abb32 | 1840 | let target = Target::from_foreign_item(f_item); |
1b1a35ee | 1841 | self.check_attributes( |
6a06907d | 1842 | f_item.hir_id(), |
1b1a35ee XL |
1843 | &f_item.span, |
1844 | target, | |
1845 | Some(ItemLike::ForeignItem(f_item)), | |
1846 | ); | |
e74abb32 XL |
1847 | intravisit::walk_foreign_item(self, f_item) |
1848 | } | |
1849 | ||
dfeec247 | 1850 | fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) { |
74b04a01 | 1851 | let target = target_from_impl_item(self.tcx, impl_item); |
6a06907d | 1852 | self.check_attributes(impl_item.hir_id(), &impl_item.span, target, None); |
e74abb32 XL |
1853 | intravisit::walk_impl_item(self, impl_item) |
1854 | } | |
0531ce1d | 1855 | |
dfeec247 | 1856 | fn visit_stmt(&mut self, stmt: &'tcx hir::Stmt<'tcx>) { |
29967ef6 XL |
1857 | // When checking statements ignore expressions, they will be checked later. |
1858 | if let hir::StmtKind::Local(ref l) = stmt.kind { | |
6a06907d | 1859 | self.check_attributes(l.hir_id, &stmt.span, Target::Statement, None); |
29967ef6 | 1860 | } |
0531ce1d XL |
1861 | intravisit::walk_stmt(self, stmt) |
1862 | } | |
1863 | ||
dfeec247 | 1864 | fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) { |
29967ef6 XL |
1865 | let target = match expr.kind { |
1866 | hir::ExprKind::Closure(..) => Target::Closure, | |
1867 | _ => Target::Expression, | |
1868 | }; | |
1869 | ||
6a06907d | 1870 | self.check_attributes(expr.hir_id, &expr.span, target, None); |
0531ce1d | 1871 | intravisit::walk_expr(self, expr) |
b039eaaf | 1872 | } |
29967ef6 XL |
1873 | |
1874 | fn visit_variant( | |
1875 | &mut self, | |
1876 | variant: &'tcx hir::Variant<'tcx>, | |
1877 | generics: &'tcx hir::Generics<'tcx>, | |
1878 | item_id: HirId, | |
1879 | ) { | |
6a06907d | 1880 | self.check_attributes(variant.id, &variant.span, Target::Variant, None); |
29967ef6 XL |
1881 | intravisit::walk_variant(self, variant, generics, item_id) |
1882 | } | |
6a06907d | 1883 | |
6a06907d XL |
1884 | fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) { |
1885 | self.check_attributes(param.hir_id, ¶m.span, Target::Param, None); | |
1886 | ||
1887 | intravisit::walk_param(self, param); | |
1888 | } | |
b039eaaf SL |
1889 | } |
1890 | ||
dfeec247 | 1891 | fn is_c_like_enum(item: &Item<'_>) -> bool { |
e74abb32 | 1892 | if let ItemKind::Enum(ref def, _) = item.kind { |
dfeec247 | 1893 | for variant in def.variants { |
e1599b0c | 1894 | match variant.data { |
9fa01778 | 1895 | hir::VariantData::Unit(..) => { /* continue */ } |
e74abb32 | 1896 | _ => return false, |
ff7c6d11 XL |
1897 | } |
1898 | } | |
1899 | true | |
1900 | } else { | |
1901 | false | |
1902 | } | |
1903 | } | |
0731742a | 1904 | |
29967ef6 XL |
1905 | fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { |
1906 | const ATTRS_TO_CHECK: &[Symbol] = &[ | |
1907 | sym::macro_export, | |
1908 | sym::repr, | |
1909 | sym::path, | |
1910 | sym::automatically_derived, | |
1911 | sym::start, | |
cdc7bbd5 | 1912 | sym::rustc_main, |
29967ef6 XL |
1913 | ]; |
1914 | ||
1915 | for attr in attrs { | |
1916 | for attr_to_check in ATTRS_TO_CHECK { | |
94222f64 | 1917 | if attr.has_name(*attr_to_check) { |
29967ef6 XL |
1918 | tcx.sess |
1919 | .struct_span_err( | |
1920 | attr.span, | |
1921 | &format!( | |
1922 | "`{}` attribute cannot be used at crate level", | |
1923 | attr_to_check.to_ident_string() | |
1924 | ), | |
1925 | ) | |
1926 | .emit(); | |
1927 | } | |
1928 | } | |
1929 | } | |
1930 | } | |
1931 | ||
94222f64 XL |
1932 | fn check_non_exported_macro_for_invalid_attrs(tcx: TyCtxt<'_>, item: &Item<'_>) { |
1933 | let attrs = tcx.hir().attrs(item.hir_id()); | |
1934 | ||
5869c6ff | 1935 | for attr in attrs { |
94222f64 | 1936 | if attr.has_name(sym::inline) { |
5869c6ff XL |
1937 | struct_span_err!( |
1938 | tcx.sess, | |
1939 | attr.span, | |
1940 | E0518, | |
1941 | "attribute should be applied to function or closure", | |
1942 | ) | |
1943 | .span_label(attr.span, "not a function or closure") | |
1944 | .emit(); | |
1945 | } | |
1946 | } | |
1947 | } | |
1948 | ||
f035d41b | 1949 | fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalDefId) { |
5869c6ff XL |
1950 | let check_attr_visitor = &mut CheckAttrVisitor { tcx }; |
1951 | tcx.hir().visit_item_likes_in_module(module_def_id, &mut check_attr_visitor.as_deep_visitor()); | |
29967ef6 | 1952 | if module_def_id.is_top_level_module() { |
6a06907d | 1953 | check_attr_visitor.check_attributes(CRATE_HIR_ID, &DUMMY_SP, Target::Mod, None); |
29967ef6 XL |
1954 | check_invalid_crate_level_attr(tcx, tcx.hir().krate_attrs()); |
1955 | } | |
0731742a XL |
1956 | } |
1957 | ||
f035d41b | 1958 | pub(crate) fn provide(providers: &mut Providers) { |
dfeec247 | 1959 | *providers = Providers { check_mod_attrs, ..*providers }; |
0731742a | 1960 | } |