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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 | |
6a06907d | 11 | use rustc_ast::{Attribute, Lit, LitKind, NestedMetaItem}; |
1b1a35ee | 12 | use rustc_errors::{pluralize, struct_span_err}; |
dfeec247 | 13 | use rustc_hir as hir; |
f035d41b | 14 | use rustc_hir::def_id::LocalDefId; |
dfeec247 | 15 | use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; |
29967ef6 XL |
16 | use rustc_hir::{ |
17 | self, FnSig, ForeignItem, ForeignItemKind, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID, | |
18 | }; | |
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 XL |
24 | use rustc_span::symbol::{sym, Symbol}; |
25 | use rustc_span::{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 XL |
68 | ) { |
69 | let mut is_valid = true; | |
6a06907d | 70 | let attrs = self.tcx.hir().attrs(hir_id); |
e74abb32 | 71 | for attr in attrs { |
3dfed10e | 72 | is_valid &= if self.tcx.sess.check_name(attr, sym::inline) { |
e74abb32 | 73 | self.check_inline(hir_id, attr, span, target) |
3dfed10e | 74 | } else if self.tcx.sess.check_name(attr, sym::non_exhaustive) { |
5869c6ff | 75 | self.check_non_exhaustive(hir_id, attr, span, target) |
3dfed10e | 76 | } else if self.tcx.sess.check_name(attr, sym::marker) { |
5869c6ff | 77 | self.check_marker(hir_id, attr, span, target) |
3dfed10e | 78 | } else if self.tcx.sess.check_name(attr, sym::target_feature) { |
1b1a35ee | 79 | self.check_target_feature(hir_id, attr, span, target) |
3dfed10e | 80 | } else if self.tcx.sess.check_name(attr, sym::track_caller) { |
5869c6ff | 81 | self.check_track_caller(hir_id, &attr.span, attrs, span, target) |
3dfed10e | 82 | } else if self.tcx.sess.check_name(attr, sym::doc) { |
fc512014 | 83 | self.check_doc_attrs(attr, hir_id, target) |
1b1a35ee | 84 | } else if self.tcx.sess.check_name(attr, sym::no_link) { |
5869c6ff | 85 | self.check_no_link(hir_id, &attr, span, target) |
1b1a35ee | 86 | } else if self.tcx.sess.check_name(attr, sym::export_name) { |
5869c6ff | 87 | self.check_export_name(hir_id, &attr, span, target) |
1b1a35ee XL |
88 | } else if self.tcx.sess.check_name(attr, sym::rustc_args_required_const) { |
89 | self.check_rustc_args_required_const(&attr, span, target, item) | |
6a06907d XL |
90 | } else if self.tcx.sess.check_name(attr, sym::rustc_layout_scalar_valid_range_start) { |
91 | self.check_rustc_layout_scalar_valid_range(&attr, span, target) | |
92 | } else if self.tcx.sess.check_name(attr, sym::rustc_layout_scalar_valid_range_end) { | |
93 | self.check_rustc_layout_scalar_valid_range(&attr, span, target) | |
29967ef6 | 94 | } else if self.tcx.sess.check_name(attr, sym::allow_internal_unstable) { |
5869c6ff | 95 | self.check_allow_internal_unstable(hir_id, &attr, span, target, &attrs) |
29967ef6 XL |
96 | } else if self.tcx.sess.check_name(attr, sym::rustc_allow_const_fn_unstable) { |
97 | self.check_rustc_allow_const_fn_unstable(hir_id, &attr, span, target) | |
fc512014 | 98 | } else if self.tcx.sess.check_name(attr, sym::naked) { |
5869c6ff | 99 | self.check_naked(hir_id, attr, span, target) |
6a06907d XL |
100 | } else if self.tcx.sess.check_name(attr, sym::rustc_legacy_const_generics) { |
101 | self.check_rustc_legacy_const_generics(&attr, span, target, item) | |
e74abb32 | 102 | } else { |
1b1a35ee XL |
103 | // lint-only checks |
104 | if self.tcx.sess.check_name(attr, sym::cold) { | |
105 | self.check_cold(hir_id, attr, span, target); | |
106 | } else if self.tcx.sess.check_name(attr, sym::link_name) { | |
107 | self.check_link_name(hir_id, attr, span, target); | |
108 | } else if self.tcx.sess.check_name(attr, sym::link_section) { | |
109 | self.check_link_section(hir_id, attr, span, target); | |
110 | } else if self.tcx.sess.check_name(attr, sym::no_mangle) { | |
111 | self.check_no_mangle(hir_id, attr, span, target); | |
112 | } | |
e74abb32 XL |
113 | true |
114 | }; | |
041b39d2 | 115 | } |
2c00a5a8 | 116 | |
e74abb32 XL |
117 | if !is_valid { |
118 | return; | |
119 | } | |
120 | ||
29967ef6 | 121 | if matches!(target, Target::Closure | Target::Fn | Target::Method(_) | Target::ForeignFn) { |
f9f354fc | 122 | self.tcx.ensure().codegen_fn_attrs(self.tcx.hir().local_def_id(hir_id)); |
e74abb32 XL |
123 | } |
124 | ||
dfeec247 | 125 | self.check_repr(attrs, span, target, item, hir_id); |
e74abb32 XL |
126 | self.check_used(attrs, target); |
127 | } | |
128 | ||
5869c6ff XL |
129 | fn inline_attr_str_error_with_macro_def(&self, hir_id: HirId, attr: &Attribute, sym: &str) { |
130 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
131 | lint.build(&format!( | |
132 | "`#[{}]` is ignored on struct fields, match arms and macro defs", | |
133 | sym, | |
134 | )) | |
135 | .warn( | |
136 | "this was previously accepted by the compiler but is \ | |
137 | being phased out; it will become a hard error in \ | |
138 | a future release!", | |
139 | ) | |
140 | .note( | |
141 | "see issue #80564 <https://github.com/rust-lang/rust/issues/80564> \ | |
142 | for more information", | |
143 | ) | |
144 | .emit(); | |
145 | }); | |
146 | } | |
147 | ||
148 | fn inline_attr_str_error_without_macro_def(&self, hir_id: HirId, attr: &Attribute, sym: &str) { | |
149 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
150 | lint.build(&format!("`#[{}]` is ignored on struct fields and match arms", sym)) | |
151 | .warn( | |
152 | "this was previously accepted by the compiler but is \ | |
153 | being phased out; it will become a hard error in \ | |
154 | a future release!", | |
155 | ) | |
156 | .note( | |
157 | "see issue #80564 <https://github.com/rust-lang/rust/issues/80564> \ | |
158 | for more information", | |
159 | ) | |
160 | .emit(); | |
161 | }); | |
162 | } | |
163 | ||
e74abb32 XL |
164 | /// Checks if an `#[inline]` is applied to a function or a closure. Returns `true` if valid. |
165 | fn check_inline(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { | |
166 | match target { | |
dfeec247 XL |
167 | Target::Fn |
168 | | Target::Closure | |
ba9703b0 | 169 | | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, |
e74abb32 | 170 | Target::Method(MethodKind::Trait { body: false }) | Target::ForeignFn => { |
74b04a01 XL |
171 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
172 | lint.build("`#[inline]` is ignored on function prototypes").emit() | |
173 | }); | |
e74abb32 XL |
174 | true |
175 | } | |
176 | // FIXME(#65833): We permit associated consts to have an `#[inline]` attribute with | |
177 | // just a lint, because we previously erroneously allowed it and some crates used it | |
178 | // accidentally, to to be compatible with crates depending on them, we can't throw an | |
179 | // error here. | |
180 | Target::AssocConst => { | |
74b04a01 XL |
181 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
182 | lint.build("`#[inline]` is ignored on constants") | |
183 | .warn( | |
184 | "this was previously accepted by the compiler but is \ | |
1b1a35ee XL |
185 | being phased out; it will become a hard error in \ |
186 | a future release!", | |
74b04a01 XL |
187 | ) |
188 | .note( | |
189 | "see issue #65833 <https://github.com/rust-lang/rust/issues/65833> \ | |
1b1a35ee | 190 | for more information", |
74b04a01 XL |
191 | ) |
192 | .emit(); | |
193 | }); | |
e74abb32 XL |
194 | true |
195 | } | |
5869c6ff XL |
196 | // FIXME(#80564): Same for fields, arms, and macro defs |
197 | Target::Field | Target::Arm | Target::MacroDef => { | |
198 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "inline"); | |
199 | true | |
200 | } | |
e74abb32 XL |
201 | _ => { |
202 | struct_span_err!( | |
203 | self.tcx.sess, | |
204 | attr.span, | |
205 | E0518, | |
206 | "attribute should be applied to function or closure", | |
dfeec247 XL |
207 | ) |
208 | .span_label(*span, "not a function or closure") | |
209 | .emit(); | |
e74abb32 XL |
210 | false |
211 | } | |
212 | } | |
041b39d2 XL |
213 | } |
214 | ||
fc512014 | 215 | /// Checks if `#[naked]` is applied to a function definition. |
5869c6ff | 216 | fn check_naked(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { |
fc512014 XL |
217 | match target { |
218 | Target::Fn | |
219 | | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, | |
5869c6ff XL |
220 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
221 | // `#[allow_internal_unstable]` attribute with just a lint, because we previously | |
222 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
223 | // with crates depending on them, we can't throw an error here. | |
224 | Target::Field | Target::Arm | Target::MacroDef => { | |
225 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "naked"); | |
226 | true | |
227 | } | |
fc512014 XL |
228 | _ => { |
229 | self.tcx | |
230 | .sess | |
231 | .struct_span_err( | |
232 | attr.span, | |
233 | "attribute should be applied to a function definition", | |
234 | ) | |
235 | .span_label(*span, "not a function definition") | |
236 | .emit(); | |
237 | false | |
238 | } | |
239 | } | |
240 | } | |
241 | ||
e74abb32 XL |
242 | /// Checks if a `#[track_caller]` is applied to a non-naked function. Returns `true` if valid. |
243 | fn check_track_caller( | |
244 | &self, | |
5869c6ff | 245 | hir_id: HirId, |
e74abb32 | 246 | attr_span: &Span, |
dfeec247 | 247 | attrs: &'hir [Attribute], |
e74abb32 XL |
248 | span: &Span, |
249 | target: Target, | |
250 | ) -> bool { | |
251 | match target { | |
fc512014 | 252 | _ if attrs.iter().any(|attr| attr.has_name(sym::naked)) => { |
e74abb32 XL |
253 | struct_span_err!( |
254 | self.tcx.sess, | |
255 | *attr_span, | |
256 | E0736, | |
257 | "cannot use `#[track_caller]` with `#[naked]`", | |
dfeec247 XL |
258 | ) |
259 | .emit(); | |
e74abb32 XL |
260 | false |
261 | } | |
1b1a35ee | 262 | Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => true, |
5869c6ff XL |
263 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
264 | // `#[track_caller]` attribute with just a lint, because we previously | |
265 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
266 | // with crates depending on them, we can't throw an error here. | |
267 | Target::Field | Target::Arm | Target::MacroDef => { | |
268 | for attr in attrs { | |
269 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "track_caller"); | |
270 | } | |
271 | true | |
272 | } | |
e74abb32 XL |
273 | _ => { |
274 | struct_span_err!( | |
275 | self.tcx.sess, | |
276 | *attr_span, | |
277 | E0739, | |
278 | "attribute should be applied to function" | |
279 | ) | |
280 | .span_label(*span, "not a function") | |
83c7162d | 281 | .emit(); |
e74abb32 XL |
282 | false |
283 | } | |
83c7162d XL |
284 | } |
285 | } | |
286 | ||
e74abb32 | 287 | /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid. Returns `true` if valid. |
5869c6ff XL |
288 | fn check_non_exhaustive( |
289 | &self, | |
290 | hir_id: HirId, | |
291 | attr: &Attribute, | |
292 | span: &Span, | |
293 | target: Target, | |
294 | ) -> bool { | |
83c7162d | 295 | match target { |
29967ef6 | 296 | Target::Struct | Target::Enum | Target::Variant => true, |
5869c6ff XL |
297 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
298 | // `#[non_exhaustive]` attribute with just a lint, because we previously | |
299 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
300 | // with crates depending on them, we can't throw an error here. | |
301 | Target::Field | Target::Arm | Target::MacroDef => { | |
302 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "non_exhaustive"); | |
303 | true | |
304 | } | |
83c7162d | 305 | _ => { |
dfeec247 XL |
306 | struct_span_err!( |
307 | self.tcx.sess, | |
308 | attr.span, | |
309 | E0701, | |
310 | "attribute can only be applied to a struct or enum" | |
311 | ) | |
312 | .span_label(*span, "not a struct or enum") | |
313 | .emit(); | |
e74abb32 | 314 | false |
83c7162d XL |
315 | } |
316 | } | |
b039eaaf SL |
317 | } |
318 | ||
e74abb32 | 319 | /// Checks if the `#[marker]` attribute on an `item` is valid. Returns `true` if valid. |
5869c6ff | 320 | fn check_marker(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { |
0bf4aa26 | 321 | match target { |
e74abb32 | 322 | Target::Trait => true, |
5869c6ff XL |
323 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
324 | // `#[marker]` attribute with just a lint, because we previously | |
325 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
326 | // with crates depending on them, we can't throw an error here. | |
327 | Target::Field | Target::Arm | Target::MacroDef => { | |
328 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "marker"); | |
329 | true | |
330 | } | |
0bf4aa26 | 331 | _ => { |
dfeec247 XL |
332 | self.tcx |
333 | .sess | |
0bf4aa26 | 334 | .struct_span_err(attr.span, "attribute can only be applied to a trait") |
e74abb32 | 335 | .span_label(*span, "not a trait") |
0bf4aa26 | 336 | .emit(); |
e74abb32 | 337 | false |
0bf4aa26 XL |
338 | } |
339 | } | |
0bf4aa26 XL |
340 | } |
341 | ||
e74abb32 | 342 | /// Checks if the `#[target_feature]` attribute on `item` is valid. Returns `true` if valid. |
1b1a35ee XL |
343 | fn check_target_feature( |
344 | &self, | |
345 | hir_id: HirId, | |
346 | attr: &Attribute, | |
347 | span: &Span, | |
348 | target: Target, | |
349 | ) -> bool { | |
e74abb32 | 350 | match target { |
dfeec247 | 351 | Target::Fn |
ba9703b0 | 352 | | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, |
1b1a35ee XL |
353 | // FIXME: #[target_feature] was previously erroneously allowed on statements and some |
354 | // crates used this, so only emit a warning. | |
355 | Target::Statement => { | |
356 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
357 | lint.build("attribute should be applied to a function") | |
358 | .warn( | |
359 | "this was previously accepted by the compiler but is \ | |
360 | being phased out; it will become a hard error in \ | |
361 | a future release!", | |
362 | ) | |
363 | .span_label(*span, "not a function") | |
364 | .emit(); | |
365 | }); | |
366 | true | |
367 | } | |
5869c6ff XL |
368 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
369 | // `#[target_feature]` attribute with just a lint, because we previously | |
370 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
371 | // with crates depending on them, we can't throw an error here. | |
372 | Target::Field | Target::Arm | Target::MacroDef => { | |
373 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "target_feature"); | |
374 | true | |
375 | } | |
e74abb32 | 376 | _ => { |
dfeec247 XL |
377 | self.tcx |
378 | .sess | |
e74abb32 XL |
379 | .struct_span_err(attr.span, "attribute should be applied to a function") |
380 | .span_label(*span, "not a function") | |
381 | .emit(); | |
382 | false | |
dfeec247 | 383 | } |
e74abb32 XL |
384 | } |
385 | } | |
386 | ||
fc512014 | 387 | fn doc_attr_str_error(&self, meta: &NestedMetaItem, attr_name: &str) { |
1b1a35ee XL |
388 | self.tcx |
389 | .sess | |
390 | .struct_span_err( | |
391 | meta.span(), | |
fc512014 | 392 | &format!("doc {0} attribute expects a string: #[doc({0} = \"a\")]", attr_name), |
1b1a35ee XL |
393 | ) |
394 | .emit(); | |
395 | } | |
396 | ||
6a06907d XL |
397 | fn check_doc_alias_value( |
398 | &self, | |
399 | meta: &NestedMetaItem, | |
400 | doc_alias: &str, | |
401 | hir_id: HirId, | |
402 | target: Target, | |
403 | is_list: bool, | |
404 | ) -> bool { | |
405 | let tcx = self.tcx; | |
406 | let err_fn = move |span: Span, msg: &str| { | |
407 | tcx.sess.span_err( | |
408 | span, | |
409 | &format!( | |
410 | "`#[doc(alias{})]` {}", | |
411 | if is_list { "(\"...\")" } else { " = \"...\"" }, | |
412 | msg, | |
413 | ), | |
414 | ); | |
415 | false | |
416 | }; | |
fc512014 | 417 | if doc_alias.is_empty() { |
6a06907d XL |
418 | return err_fn( |
419 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
420 | "attribute cannot have empty value", | |
421 | ); | |
fc512014 XL |
422 | } |
423 | if let Some(c) = | |
424 | doc_alias.chars().find(|&c| c == '"' || c == '\'' || (c.is_whitespace() && c != ' ')) | |
425 | { | |
6a06907d XL |
426 | self.tcx.sess.span_err( |
427 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
428 | &format!( | |
429 | "{:?} character isn't allowed in `#[doc(alias{})]`", | |
430 | c, | |
431 | if is_list { "(\"...\")" } else { " = \"...\"" }, | |
432 | ), | |
433 | ); | |
fc512014 XL |
434 | return false; |
435 | } | |
436 | if doc_alias.starts_with(' ') || doc_alias.ends_with(' ') { | |
6a06907d XL |
437 | return err_fn( |
438 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
439 | "cannot start or end with ' '", | |
440 | ); | |
fc512014 XL |
441 | } |
442 | if let Some(err) = match target { | |
443 | Target::Impl => Some("implementation block"), | |
444 | Target::ForeignMod => Some("extern block"), | |
445 | Target::AssocTy => { | |
446 | let parent_hir_id = self.tcx.hir().get_parent_item(hir_id); | |
447 | let containing_item = self.tcx.hir().expect_item(parent_hir_id); | |
448 | if Target::from_item(containing_item) == Target::Impl { | |
449 | Some("type alias in implementation block") | |
450 | } else { | |
451 | None | |
452 | } | |
453 | } | |
454 | Target::AssocConst => { | |
455 | let parent_hir_id = self.tcx.hir().get_parent_item(hir_id); | |
456 | let containing_item = self.tcx.hir().expect_item(parent_hir_id); | |
457 | // We can't link to trait impl's consts. | |
458 | let err = "associated constant in trait implementation block"; | |
459 | match containing_item.kind { | |
5869c6ff | 460 | ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) => Some(err), |
fc512014 XL |
461 | _ => None, |
462 | } | |
463 | } | |
464 | _ => None, | |
465 | } { | |
6a06907d | 466 | return err_fn(meta.span(), &format!("isn't allowed on {}", err)); |
fc512014 | 467 | } |
5869c6ff XL |
468 | let item_name = self.tcx.hir().name(hir_id); |
469 | if &*item_name.as_str() == doc_alias { | |
6a06907d XL |
470 | return err_fn(meta.span(), "is the same as the item's name"); |
471 | } | |
472 | true | |
473 | } | |
474 | ||
475 | fn check_doc_alias(&self, meta: &NestedMetaItem, hir_id: HirId, target: Target) -> bool { | |
476 | if let Some(values) = meta.meta_item_list() { | |
477 | let mut errors = 0; | |
478 | for v in values { | |
479 | match v.literal() { | |
480 | Some(l) => match l.kind { | |
481 | LitKind::Str(s, _) => { | |
482 | if !self.check_doc_alias_value(v, &s.as_str(), hir_id, target, true) { | |
483 | errors += 1; | |
484 | } | |
485 | } | |
486 | _ => { | |
487 | self.tcx | |
488 | .sess | |
489 | .struct_span_err( | |
490 | v.span(), | |
491 | "`#[doc(alias(\"a\"))]` expects string literals", | |
492 | ) | |
493 | .emit(); | |
494 | errors += 1; | |
495 | } | |
496 | }, | |
497 | None => { | |
498 | self.tcx | |
499 | .sess | |
500 | .struct_span_err( | |
501 | v.span(), | |
502 | "`#[doc(alias(\"a\"))]` expects string literals", | |
503 | ) | |
504 | .emit(); | |
505 | errors += 1; | |
506 | } | |
507 | } | |
508 | } | |
509 | errors == 0 | |
510 | } else if let Some(doc_alias) = meta.value_str().map(|s| s.to_string()) { | |
511 | self.check_doc_alias_value(meta, &doc_alias, hir_id, target, false) | |
512 | } else { | |
5869c6ff XL |
513 | self.tcx |
514 | .sess | |
515 | .struct_span_err( | |
516 | meta.span(), | |
6a06907d XL |
517 | "doc alias attribute expects a string `#[doc(alias = \"a\")]` or a list of \ |
518 | strings `#[doc(alias(\"a\", \"b\"))]`", | |
5869c6ff XL |
519 | ) |
520 | .emit(); | |
6a06907d | 521 | false |
5869c6ff | 522 | } |
fc512014 XL |
523 | } |
524 | ||
525 | fn check_doc_keyword(&self, meta: &NestedMetaItem, hir_id: HirId) -> bool { | |
526 | let doc_keyword = meta.value_str().map(|s| s.to_string()).unwrap_or_else(String::new); | |
527 | if doc_keyword.is_empty() { | |
528 | self.doc_attr_str_error(meta, "keyword"); | |
529 | return false; | |
530 | } | |
531 | match self.tcx.hir().expect_item(hir_id).kind { | |
532 | ItemKind::Mod(ref module) => { | |
533 | if !module.item_ids.is_empty() { | |
534 | self.tcx | |
535 | .sess | |
536 | .struct_span_err( | |
537 | meta.span(), | |
538 | "`#[doc(keyword = \"...\")]` can only be used on empty modules", | |
539 | ) | |
540 | .emit(); | |
541 | return false; | |
542 | } | |
543 | } | |
544 | _ => { | |
545 | self.tcx | |
546 | .sess | |
547 | .struct_span_err( | |
548 | meta.span(), | |
549 | "`#[doc(keyword = \"...\")]` can only be used on modules", | |
550 | ) | |
551 | .emit(); | |
552 | return false; | |
553 | } | |
554 | } | |
555 | if !rustc_lexer::is_ident(&doc_keyword) { | |
556 | self.tcx | |
557 | .sess | |
558 | .struct_span_err( | |
559 | meta.name_value_literal_span().unwrap_or_else(|| meta.span()), | |
560 | &format!("`{}` is not a valid identifier", doc_keyword), | |
561 | ) | |
562 | .emit(); | |
563 | return false; | |
564 | } | |
565 | true | |
566 | } | |
567 | ||
568 | fn check_attr_crate_level( | |
569 | &self, | |
570 | meta: &NestedMetaItem, | |
571 | hir_id: HirId, | |
572 | attr_name: &str, | |
573 | ) -> bool { | |
574 | if CRATE_HIR_ID == hir_id { | |
575 | self.tcx | |
576 | .sess | |
577 | .struct_span_err( | |
578 | meta.span(), | |
579 | &format!( | |
6a06907d | 580 | "`#![doc({} = \"...\")]` isn't allowed as a crate-level attribute", |
fc512014 XL |
581 | attr_name, |
582 | ), | |
583 | ) | |
584 | .emit(); | |
585 | return false; | |
586 | } | |
587 | true | |
588 | } | |
589 | ||
590 | fn check_doc_attrs(&self, attr: &Attribute, hir_id: HirId, target: Target) -> bool { | |
6a06907d XL |
591 | let mut is_valid = true; |
592 | ||
593 | if let Some(list) = attr.meta().and_then(|mi| mi.meta_item_list().map(|l| l.to_vec())) { | |
594 | for meta in list { | |
595 | if let Some(i_meta) = meta.meta_item() { | |
596 | match i_meta.name_or_empty() { | |
597 | sym::alias | |
598 | if !self.check_attr_crate_level(&meta, hir_id, "alias") | |
599 | || !self.check_doc_alias(&meta, hir_id, target) => | |
3dfed10e | 600 | { |
6a06907d | 601 | is_valid = false |
29967ef6 | 602 | } |
6a06907d XL |
603 | |
604 | sym::keyword | |
605 | if !self.check_attr_crate_level(&meta, hir_id, "keyword") | |
606 | || !self.check_doc_keyword(&meta, hir_id) => | |
fc512014 | 607 | { |
6a06907d XL |
608 | is_valid = false |
609 | } | |
610 | ||
611 | sym::test if CRATE_HIR_ID != hir_id => { | |
612 | self.tcx.struct_span_lint_hir( | |
613 | INVALID_DOC_ATTRIBUTES, | |
614 | hir_id, | |
615 | meta.span(), | |
616 | |lint| { | |
617 | lint.build( | |
618 | "`#![doc(test(...)]` is only allowed \ | |
619 | as a crate-level attribute", | |
620 | ) | |
621 | .emit(); | |
622 | }, | |
623 | ); | |
624 | is_valid = false; | |
625 | } | |
626 | ||
627 | // no_default_passes: deprecated | |
628 | // passes: deprecated | |
629 | // plugins: removed, but rustdoc warns about it itself | |
630 | sym::alias | |
631 | | sym::cfg | |
632 | | sym::hidden | |
633 | | sym::html_favicon_url | |
634 | | sym::html_logo_url | |
635 | | sym::html_no_source | |
636 | | sym::html_playground_url | |
637 | | sym::html_root_url | |
638 | | sym::include | |
639 | | sym::inline | |
640 | | sym::issue_tracker_base_url | |
641 | | sym::keyword | |
642 | | sym::masked | |
643 | | sym::no_default_passes | |
644 | | sym::no_inline | |
645 | | sym::passes | |
646 | | sym::plugins | |
647 | | sym::primitive | |
648 | | sym::spotlight | |
649 | | sym::test => {} | |
650 | ||
651 | _ => { | |
652 | self.tcx.struct_span_lint_hir( | |
653 | INVALID_DOC_ATTRIBUTES, | |
654 | hir_id, | |
655 | i_meta.span, | |
656 | |lint| { | |
657 | let msg = format!( | |
658 | "unknown `doc` attribute `{}`", | |
659 | rustc_ast_pretty::pprust::path_to_string(&i_meta.path), | |
660 | ); | |
661 | lint.build(&msg).emit(); | |
662 | }, | |
663 | ); | |
664 | is_valid = false; | |
29967ef6 | 665 | } |
3dfed10e | 666 | } |
6a06907d XL |
667 | } else { |
668 | self.tcx.struct_span_lint_hir( | |
669 | INVALID_DOC_ATTRIBUTES, | |
670 | hir_id, | |
671 | meta.span(), | |
672 | |lint| { | |
673 | lint.build(&format!("invalid `doc` attribute")).emit(); | |
674 | }, | |
675 | ); | |
676 | is_valid = false; | |
3dfed10e XL |
677 | } |
678 | } | |
679 | } | |
6a06907d XL |
680 | |
681 | is_valid | |
3dfed10e XL |
682 | } |
683 | ||
1b1a35ee XL |
684 | /// Checks if `#[cold]` is applied to a non-function. Returns `true` if valid. |
685 | fn check_cold(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
686 | match target { | |
687 | Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => {} | |
5869c6ff XL |
688 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
689 | // `#[cold]` attribute with just a lint, because we previously | |
690 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
691 | // with crates depending on them, we can't throw an error here. | |
692 | Target::Field | Target::Arm | Target::MacroDef => { | |
693 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "cold"); | |
694 | } | |
1b1a35ee XL |
695 | _ => { |
696 | // FIXME: #[cold] was previously allowed on non-functions and some crates used | |
697 | // this, so only emit a warning. | |
698 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
699 | lint.build("attribute should be applied to a function") | |
700 | .warn( | |
701 | "this was previously accepted by the compiler but is \ | |
702 | being phased out; it will become a hard error in \ | |
703 | a future release!", | |
704 | ) | |
705 | .span_label(*span, "not a function") | |
706 | .emit(); | |
707 | }); | |
708 | } | |
709 | } | |
710 | } | |
711 | ||
712 | /// Checks if `#[link_name]` is applied to an item other than a foreign function or static. | |
713 | fn check_link_name(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
714 | match target { | |
715 | Target::ForeignFn | Target::ForeignStatic => {} | |
5869c6ff XL |
716 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
717 | // `#[link_name]` attribute with just a lint, because we previously | |
718 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
719 | // with crates depending on them, we can't throw an error here. | |
720 | Target::Field | Target::Arm | Target::MacroDef => { | |
721 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "link_name"); | |
722 | } | |
1b1a35ee XL |
723 | _ => { |
724 | // FIXME: #[cold] was previously allowed on non-functions/statics and some crates | |
725 | // used this, so only emit a warning. | |
726 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
727 | let mut diag = | |
728 | lint.build("attribute should be applied to a foreign function or static"); | |
729 | diag.warn( | |
730 | "this was previously accepted by the compiler but is \ | |
731 | being phased out; it will become a hard error in \ | |
732 | a future release!", | |
733 | ); | |
734 | ||
735 | // See issue #47725 | |
736 | if let Target::ForeignMod = target { | |
737 | if let Some(value) = attr.value_str() { | |
738 | diag.span_help( | |
739 | attr.span, | |
740 | &format!(r#"try `#[link(name = "{}")]` instead"#, value), | |
741 | ); | |
742 | } else { | |
743 | diag.span_help(attr.span, r#"try `#[link(name = "...")]` instead"#); | |
744 | } | |
745 | } | |
746 | ||
747 | diag.span_label(*span, "not a foreign function or static"); | |
748 | diag.emit(); | |
749 | }); | |
750 | } | |
751 | } | |
752 | } | |
753 | ||
754 | /// Checks if `#[no_link]` is applied to an `extern crate`. Returns `true` if valid. | |
5869c6ff XL |
755 | fn check_no_link(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { |
756 | match target { | |
757 | Target::ExternCrate => true, | |
758 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an | |
759 | // `#[no_link]` attribute with just a lint, because we previously | |
760 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
761 | // with crates depending on them, we can't throw an error here. | |
762 | Target::Field | Target::Arm | Target::MacroDef => { | |
763 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "no_link"); | |
764 | true | |
765 | } | |
766 | _ => { | |
767 | self.tcx | |
768 | .sess | |
769 | .struct_span_err( | |
770 | attr.span, | |
771 | "attribute should be applied to an `extern crate` item", | |
772 | ) | |
773 | .span_label(*span, "not an `extern crate` item") | |
774 | .emit(); | |
775 | false | |
776 | } | |
1b1a35ee XL |
777 | } |
778 | } | |
779 | ||
780 | /// Checks if `#[export_name]` is applied to a function or static. Returns `true` if valid. | |
5869c6ff XL |
781 | fn check_export_name( |
782 | &self, | |
783 | hir_id: HirId, | |
784 | attr: &Attribute, | |
785 | span: &Span, | |
786 | target: Target, | |
787 | ) -> bool { | |
1b1a35ee XL |
788 | match target { |
789 | Target::Static | Target::Fn | Target::Method(..) => true, | |
5869c6ff XL |
790 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
791 | // `#[export_name]` attribute with just a lint, because we previously | |
792 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
793 | // with crates depending on them, we can't throw an error here. | |
794 | Target::Field | Target::Arm | Target::MacroDef => { | |
795 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "export_name"); | |
796 | true | |
797 | } | |
1b1a35ee XL |
798 | _ => { |
799 | self.tcx | |
800 | .sess | |
801 | .struct_span_err( | |
802 | attr.span, | |
803 | "attribute should be applied to a function or static", | |
804 | ) | |
805 | .span_label(*span, "not a function or static") | |
806 | .emit(); | |
807 | false | |
808 | } | |
809 | } | |
810 | } | |
811 | ||
812 | /// Checks if `#[rustc_args_required_const]` is applied to a function and has a valid argument. | |
813 | fn check_rustc_args_required_const( | |
814 | &self, | |
815 | attr: &Attribute, | |
816 | span: &Span, | |
817 | target: Target, | |
818 | item: Option<ItemLike<'_>>, | |
819 | ) -> bool { | |
fc512014 XL |
820 | let is_function = matches!(target, Target::Fn | Target::Method(..) | Target::ForeignFn); |
821 | if !is_function { | |
822 | self.tcx | |
823 | .sess | |
824 | .struct_span_err(attr.span, "attribute should be applied to a function") | |
825 | .span_label(*span, "not a function") | |
826 | .emit(); | |
827 | return false; | |
828 | } | |
829 | ||
830 | let list = match attr.meta_item_list() { | |
831 | // The attribute form is validated on AST. | |
832 | None => return false, | |
833 | Some(it) => it, | |
834 | }; | |
835 | ||
836 | let mut invalid_args = vec![]; | |
837 | for meta in list { | |
838 | if let Some(LitKind::Int(val, _)) = meta.literal().map(|lit| &lit.kind) { | |
839 | if let Some(ItemLike::Item(Item { | |
840 | kind: ItemKind::Fn(FnSig { decl, .. }, ..), | |
841 | .. | |
842 | })) | |
843 | | Some(ItemLike::ForeignItem(ForeignItem { | |
844 | kind: ForeignItemKind::Fn(decl, ..), | |
845 | .. | |
846 | })) = item | |
847 | { | |
848 | let arg_count = decl.inputs.len() as u128; | |
849 | if *val >= arg_count { | |
850 | let span = meta.span(); | |
851 | self.tcx | |
852 | .sess | |
853 | .struct_span_err(span, "index exceeds number of arguments") | |
854 | .span_label( | |
855 | span, | |
856 | format!( | |
857 | "there {} only {} argument{}", | |
858 | if arg_count != 1 { "are" } else { "is" }, | |
859 | arg_count, | |
860 | pluralize!(arg_count) | |
861 | ), | |
862 | ) | |
863 | .emit(); | |
864 | return false; | |
1b1a35ee XL |
865 | } |
866 | } else { | |
fc512014 | 867 | bug!("should be a function item"); |
1b1a35ee | 868 | } |
1b1a35ee | 869 | } else { |
fc512014 | 870 | invalid_args.push(meta.span()); |
1b1a35ee | 871 | } |
fc512014 XL |
872 | } |
873 | ||
874 | if !invalid_args.is_empty() { | |
1b1a35ee XL |
875 | self.tcx |
876 | .sess | |
fc512014 | 877 | .struct_span_err(invalid_args, "arguments should be non-negative integers") |
1b1a35ee XL |
878 | .emit(); |
879 | false | |
fc512014 XL |
880 | } else { |
881 | true | |
1b1a35ee XL |
882 | } |
883 | } | |
884 | ||
6a06907d XL |
885 | fn check_rustc_layout_scalar_valid_range( |
886 | &self, | |
887 | attr: &Attribute, | |
888 | span: &Span, | |
889 | target: Target, | |
890 | ) -> bool { | |
891 | if target != Target::Struct { | |
892 | self.tcx | |
893 | .sess | |
894 | .struct_span_err(attr.span, "attribute should be applied to a struct") | |
895 | .span_label(*span, "not a struct") | |
896 | .emit(); | |
897 | return false; | |
898 | } | |
899 | ||
900 | let list = match attr.meta_item_list() { | |
901 | None => return false, | |
902 | Some(it) => it, | |
903 | }; | |
904 | ||
905 | if matches!(&list[..], &[NestedMetaItem::Literal(Lit { kind: LitKind::Int(..), .. })]) { | |
906 | true | |
907 | } else { | |
908 | self.tcx | |
909 | .sess | |
910 | .struct_span_err(attr.span, "expected exactly one integer literal argument") | |
911 | .emit(); | |
912 | false | |
913 | } | |
914 | } | |
915 | ||
916 | /// Checks if `#[rustc_legacy_const_generics]` is applied to a function and has a valid argument. | |
917 | fn check_rustc_legacy_const_generics( | |
918 | &self, | |
919 | attr: &Attribute, | |
920 | span: &Span, | |
921 | target: Target, | |
922 | item: Option<ItemLike<'_>>, | |
923 | ) -> bool { | |
924 | let is_function = matches!(target, Target::Fn | Target::Method(..)); | |
925 | if !is_function { | |
926 | self.tcx | |
927 | .sess | |
928 | .struct_span_err(attr.span, "attribute should be applied to a function") | |
929 | .span_label(*span, "not a function") | |
930 | .emit(); | |
931 | return false; | |
932 | } | |
933 | ||
934 | let list = match attr.meta_item_list() { | |
935 | // The attribute form is validated on AST. | |
936 | None => return false, | |
937 | Some(it) => it, | |
938 | }; | |
939 | ||
940 | let (decl, generics) = match item { | |
941 | Some(ItemLike::Item(Item { | |
942 | kind: ItemKind::Fn(FnSig { decl, .. }, generics, _), | |
943 | .. | |
944 | })) => (decl, generics), | |
945 | _ => bug!("should be a function item"), | |
946 | }; | |
947 | ||
948 | for param in generics.params { | |
949 | match param.kind { | |
950 | hir::GenericParamKind::Const { .. } => {} | |
951 | _ => { | |
952 | self.tcx | |
953 | .sess | |
954 | .struct_span_err( | |
955 | attr.span, | |
956 | "#[rustc_legacy_const_generics] functions must \ | |
957 | only have const generics", | |
958 | ) | |
959 | .span_label(param.span, "non-const generic parameter") | |
960 | .emit(); | |
961 | return false; | |
962 | } | |
963 | } | |
964 | } | |
965 | ||
966 | if list.len() != generics.params.len() { | |
967 | self.tcx | |
968 | .sess | |
969 | .struct_span_err( | |
970 | attr.span, | |
971 | "#[rustc_legacy_const_generics] must have one index for each generic parameter", | |
972 | ) | |
973 | .span_label(generics.span, "generic parameters") | |
974 | .emit(); | |
975 | return false; | |
976 | } | |
977 | ||
978 | let arg_count = decl.inputs.len() as u128 + generics.params.len() as u128; | |
979 | let mut invalid_args = vec![]; | |
980 | for meta in list { | |
981 | if let Some(LitKind::Int(val, _)) = meta.literal().map(|lit| &lit.kind) { | |
982 | if *val >= arg_count { | |
983 | let span = meta.span(); | |
984 | self.tcx | |
985 | .sess | |
986 | .struct_span_err(span, "index exceeds number of arguments") | |
987 | .span_label( | |
988 | span, | |
989 | format!( | |
990 | "there {} only {} argument{}", | |
991 | if arg_count != 1 { "are" } else { "is" }, | |
992 | arg_count, | |
993 | pluralize!(arg_count) | |
994 | ), | |
995 | ) | |
996 | .emit(); | |
997 | return false; | |
998 | } | |
999 | } else { | |
1000 | invalid_args.push(meta.span()); | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | if !invalid_args.is_empty() { | |
1005 | self.tcx | |
1006 | .sess | |
1007 | .struct_span_err(invalid_args, "arguments should be non-negative integers") | |
1008 | .emit(); | |
1009 | false | |
1010 | } else { | |
1011 | true | |
1012 | } | |
1013 | } | |
1014 | ||
1b1a35ee XL |
1015 | /// Checks if `#[link_section]` is applied to a function or static. |
1016 | fn check_link_section(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
1017 | match target { | |
1018 | Target::Static | Target::Fn | Target::Method(..) => {} | |
5869c6ff XL |
1019 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
1020 | // `#[link_section]` attribute with just a lint, because we previously | |
1021 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1022 | // with crates depending on them, we can't throw an error here. | |
1023 | Target::Field | Target::Arm | Target::MacroDef => { | |
1024 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "link_section"); | |
1025 | } | |
1b1a35ee XL |
1026 | _ => { |
1027 | // FIXME: #[link_section] was previously allowed on non-functions/statics and some | |
1028 | // crates used this, so only emit a warning. | |
1029 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1030 | lint.build("attribute should be applied to a function or static") | |
1031 | .warn( | |
1032 | "this was previously accepted by the compiler but is \ | |
1033 | being phased out; it will become a hard error in \ | |
1034 | a future release!", | |
1035 | ) | |
1036 | .span_label(*span, "not a function or static") | |
1037 | .emit(); | |
1038 | }); | |
1039 | } | |
1040 | } | |
1041 | } | |
1042 | ||
1043 | /// Checks if `#[no_mangle]` is applied to a function or static. | |
1044 | fn check_no_mangle(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { | |
1045 | match target { | |
1046 | Target::Static | Target::Fn | Target::Method(..) => {} | |
5869c6ff XL |
1047 | // FIXME(#80564): We permit struct fields, match arms and macro defs to have an |
1048 | // `#[no_mangle]` attribute with just a lint, because we previously | |
1049 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1050 | // with crates depending on them, we can't throw an error here. | |
1051 | Target::Field | Target::Arm | Target::MacroDef => { | |
1052 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "no_mangle"); | |
1053 | } | |
1b1a35ee XL |
1054 | _ => { |
1055 | // FIXME: #[no_mangle] was previously allowed on non-functions/statics and some | |
1056 | // crates used this, so only emit a warning. | |
1057 | self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { | |
1058 | lint.build("attribute should be applied to a function or static") | |
1059 | .warn( | |
1060 | "this was previously accepted by the compiler but is \ | |
1061 | being phased out; it will become a hard error in \ | |
1062 | a future release!", | |
1063 | ) | |
1064 | .span_label(*span, "not a function or static") | |
1065 | .emit(); | |
1066 | }); | |
1067 | } | |
1068 | } | |
1069 | } | |
1070 | ||
9fa01778 | 1071 | /// Checks if the `#[repr]` attributes on `item` are valid. |
e74abb32 XL |
1072 | fn check_repr( |
1073 | &self, | |
dfeec247 | 1074 | attrs: &'hir [Attribute], |
e74abb32 XL |
1075 | span: &Span, |
1076 | target: Target, | |
1b1a35ee | 1077 | item: Option<ItemLike<'_>>, |
dfeec247 | 1078 | hir_id: HirId, |
e74abb32 | 1079 | ) { |
2c00a5a8 XL |
1080 | // Extract the names of all repr hints, e.g., [foo, bar, align] for: |
1081 | // ``` | |
1082 | // #[repr(foo)] | |
1083 | // #[repr(bar, align(8))] | |
1084 | // ``` | |
e74abb32 | 1085 | let hints: Vec<_> = attrs |
2c00a5a8 | 1086 | .iter() |
3dfed10e | 1087 | .filter(|attr| self.tcx.sess.check_name(attr, sym::repr)) |
2c00a5a8 | 1088 | .filter_map(|attr| attr.meta_item_list()) |
b7449926 | 1089 | .flatten() |
2c00a5a8 | 1090 | .collect(); |
9e0c209e | 1091 | |
ff7c6d11 XL |
1092 | let mut int_reprs = 0; |
1093 | let mut is_c = false; | |
1094 | let mut is_simd = false; | |
2c00a5a8 XL |
1095 | let mut is_transparent = false; |
1096 | ||
1097 | for hint in &hints { | |
48663c56 | 1098 | let (article, allowed_targets) = match hint.name_or_empty() { |
29967ef6 XL |
1099 | _ if !matches!(target, Target::Struct | Target::Enum | Target::Union) => { |
1100 | ("a", "struct, enum, or union") | |
1101 | } | |
48663c56 XL |
1102 | name @ sym::C | name @ sym::align => { |
1103 | is_c |= name == sym::C; | |
dc9dc135 XL |
1104 | match target { |
1105 | Target::Struct | Target::Union | Target::Enum => continue, | |
1106 | _ => ("a", "struct, enum, or union"), | |
9e0c209e SL |
1107 | } |
1108 | } | |
48663c56 | 1109 | sym::packed => { |
dfeec247 XL |
1110 | if target != Target::Struct && target != Target::Union { |
1111 | ("a", "struct or union") | |
92a42be0 | 1112 | } else { |
dfeec247 | 1113 | continue; |
b039eaaf SL |
1114 | } |
1115 | } | |
48663c56 | 1116 | sym::simd => { |
ff7c6d11 | 1117 | is_simd = true; |
1b1a35ee XL |
1118 | if target != Target::Struct { |
1119 | ("a", "struct") | |
1120 | } else { | |
1121 | continue; | |
1122 | } | |
b039eaaf | 1123 | } |
48663c56 | 1124 | sym::transparent => { |
2c00a5a8 | 1125 | is_transparent = true; |
dc9dc135 XL |
1126 | match target { |
1127 | Target::Struct | Target::Union | Target::Enum => continue, | |
1128 | _ => ("a", "struct, enum, or union"), | |
cc61c64b XL |
1129 | } |
1130 | } | |
74b04a01 XL |
1131 | sym::no_niche => { |
1132 | if !self.tcx.features().enabled(sym::no_niche) { | |
1133 | feature_err( | |
1134 | &self.tcx.sess.parse_sess, | |
1135 | sym::no_niche, | |
1136 | hint.span(), | |
1137 | "the attribute `repr(no_niche)` is currently unstable", | |
1138 | ) | |
1139 | .emit(); | |
1140 | } | |
1141 | match target { | |
1142 | Target::Struct | Target::Enum => continue, | |
1143 | _ => ("a", "struct or enum"), | |
1144 | } | |
1145 | } | |
dfeec247 XL |
1146 | sym::i8 |
1147 | | sym::u8 | |
1148 | | sym::i16 | |
1149 | | sym::u16 | |
1150 | | sym::i32 | |
1151 | | sym::u32 | |
1152 | | sym::i64 | |
1153 | | sym::u64 | |
f035d41b XL |
1154 | | sym::i128 |
1155 | | sym::u128 | |
dfeec247 XL |
1156 | | sym::isize |
1157 | | sym::usize => { | |
ff7c6d11 | 1158 | int_reprs += 1; |
1b1a35ee XL |
1159 | if target != Target::Enum { |
1160 | ("an", "enum") | |
1161 | } else { | |
1162 | continue; | |
1163 | } | |
b039eaaf | 1164 | } |
92a42be0 SL |
1165 | _ => continue, |
1166 | }; | |
29967ef6 XL |
1167 | |
1168 | struct_span_err!( | |
1169 | self.tcx.sess, | |
532ac7d7 | 1170 | hint.span(), |
29967ef6 XL |
1171 | E0517, |
1172 | "{}", | |
1173 | &format!("attribute should be applied to {} {}", article, allowed_targets) | |
0531ce1d | 1174 | ) |
29967ef6 XL |
1175 | .span_label(*span, &format!("not {} {}", article, allowed_targets)) |
1176 | .emit(); | |
9e0c209e | 1177 | } |
ff7c6d11 | 1178 | |
2c00a5a8 XL |
1179 | // Just point at all repr hints if there are any incompatibilities. |
1180 | // This is not ideal, but tracking precisely which ones are at fault is a huge hassle. | |
532ac7d7 | 1181 | let hint_spans = hints.iter().map(|hint| hint.span()); |
2c00a5a8 | 1182 | |
74b04a01 XL |
1183 | // Error on repr(transparent, <anything else apart from no_niche>). |
1184 | let non_no_niche = |hint: &&NestedMetaItem| hint.name_or_empty() != sym::no_niche; | |
1185 | let non_no_niche_count = hints.iter().filter(non_no_niche).count(); | |
1186 | if is_transparent && non_no_niche_count > 1 { | |
2c00a5a8 | 1187 | let hint_spans: Vec<_> = hint_spans.clone().collect(); |
dfeec247 XL |
1188 | struct_span_err!( |
1189 | self.tcx.sess, | |
1190 | hint_spans, | |
1191 | E0692, | |
1192 | "transparent {} cannot have other repr hints", | |
1193 | target | |
1194 | ) | |
1195 | .emit(); | |
2c00a5a8 | 1196 | } |
ff7c6d11 XL |
1197 | // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8) |
1198 | if (int_reprs > 1) | |
dfeec247 | 1199 | || (is_simd && is_c) |
1b1a35ee XL |
1200 | || (int_reprs == 1 |
1201 | && is_c | |
1202 | && item.map_or(false, |item| { | |
1203 | if let ItemLike::Item(item) = item { | |
1204 | return is_c_like_enum(item); | |
1205 | } | |
1206 | return false; | |
1207 | })) | |
dfeec247 | 1208 | { |
74b04a01 XL |
1209 | self.tcx.struct_span_lint_hir( |
1210 | CONFLICTING_REPR_HINTS, | |
1211 | hir_id, | |
1212 | hint_spans.collect::<Vec<Span>>(), | |
1213 | |lint| { | |
1214 | lint.build("conflicting representation hints") | |
1215 | .code(rustc_errors::error_code!(E0566)) | |
1216 | .emit(); | |
1217 | }, | |
1218 | ); | |
b039eaaf SL |
1219 | } |
1220 | } | |
0531ce1d | 1221 | |
29967ef6 XL |
1222 | fn check_used(&self, attrs: &'hir [Attribute], target: Target) { |
1223 | for attr in attrs { | |
1224 | if self.tcx.sess.check_name(attr, sym::used) && target != Target::Static { | |
1225 | self.tcx | |
1226 | .sess | |
1227 | .span_err(attr.span, "attribute must be applied to a `static` variable"); | |
0531ce1d XL |
1228 | } |
1229 | } | |
1230 | } | |
1231 | ||
29967ef6 XL |
1232 | /// Outputs an error for `#[allow_internal_unstable]` which can only be applied to macros. |
1233 | /// (Allows proc_macro functions) | |
1234 | fn check_allow_internal_unstable( | |
1235 | &self, | |
5869c6ff | 1236 | hir_id: HirId, |
29967ef6 XL |
1237 | attr: &Attribute, |
1238 | span: &Span, | |
1239 | target: Target, | |
1240 | attrs: &[Attribute], | |
1241 | ) -> bool { | |
1242 | debug!("Checking target: {:?}", target); | |
5869c6ff XL |
1243 | match target { |
1244 | Target::Fn => { | |
1245 | for attr in attrs { | |
1246 | if self.tcx.sess.is_proc_macro_attr(attr) { | |
1247 | debug!("Is proc macro attr"); | |
1248 | return true; | |
1249 | } | |
29967ef6 | 1250 | } |
5869c6ff XL |
1251 | debug!("Is not proc macro attr"); |
1252 | false | |
1253 | } | |
1254 | Target::MacroDef => true, | |
1255 | // FIXME(#80564): We permit struct fields and match arms to have an | |
1256 | // `#[allow_internal_unstable]` attribute with just a lint, because we previously | |
1257 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1258 | // with crates depending on them, we can't throw an error here. | |
1259 | Target::Field | Target::Arm => { | |
1260 | self.inline_attr_str_error_without_macro_def( | |
1261 | hir_id, | |
1262 | attr, | |
1263 | "allow_internal_unstable", | |
1264 | ); | |
1265 | true | |
1266 | } | |
1267 | _ => { | |
1268 | self.tcx | |
1269 | .sess | |
1270 | .struct_span_err(attr.span, "attribute should be applied to a macro") | |
1271 | .span_label(*span, "not a macro") | |
1272 | .emit(); | |
1273 | false | |
0531ce1d XL |
1274 | } |
1275 | } | |
1276 | } | |
83c7162d | 1277 | |
29967ef6 XL |
1278 | /// Outputs an error for `#[allow_internal_unstable]` which can only be applied to macros. |
1279 | /// (Allows proc_macro functions) | |
1280 | fn check_rustc_allow_const_fn_unstable( | |
1281 | &self, | |
1282 | hir_id: HirId, | |
1283 | attr: &Attribute, | |
1284 | span: &Span, | |
1285 | target: Target, | |
1286 | ) -> bool { | |
5869c6ff XL |
1287 | match target { |
1288 | Target::Fn | Target::Method(_) | |
1289 | if self.tcx.is_const_fn_raw(self.tcx.hir().local_def_id(hir_id)) => | |
1290 | { | |
1291 | true | |
1292 | } | |
1293 | // FIXME(#80564): We permit struct fields and match arms to have an | |
1294 | // `#[allow_internal_unstable]` attribute with just a lint, because we previously | |
1295 | // erroneously allowed it and some crates used it accidentally, to to be compatible | |
1296 | // with crates depending on them, we can't throw an error here. | |
1297 | Target::Field | Target::Arm | Target::MacroDef => { | |
1298 | self.inline_attr_str_error_with_macro_def(hir_id, attr, "allow_internal_unstable"); | |
1299 | true | |
1300 | } | |
1301 | _ => { | |
1302 | self.tcx | |
1303 | .sess | |
1304 | .struct_span_err(attr.span, "attribute should be applied to `const fn`") | |
1305 | .span_label(*span, "not a `const fn`") | |
1306 | .emit(); | |
1307 | false | |
83c7162d XL |
1308 | } |
1309 | } | |
1310 | } | |
b039eaaf SL |
1311 | } |
1312 | ||
dc9dc135 | 1313 | impl Visitor<'tcx> for CheckAttrVisitor<'tcx> { |
dfeec247 XL |
1314 | type Map = Map<'tcx>; |
1315 | ||
ba9703b0 XL |
1316 | fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { |
1317 | NestedVisitorMap::OnlyBodies(self.tcx.hir()) | |
2c00a5a8 XL |
1318 | } |
1319 | ||
dfeec247 | 1320 | fn visit_item(&mut self, item: &'tcx Item<'tcx>) { |
b039eaaf | 1321 | let target = Target::from_item(item); |
6a06907d | 1322 | self.check_attributes(item.hir_id(), &item.span, target, Some(ItemLike::Item(item))); |
0531ce1d XL |
1323 | intravisit::walk_item(self, item) |
1324 | } | |
1325 | ||
fc512014 XL |
1326 | fn visit_generic_param(&mut self, generic_param: &'tcx hir::GenericParam<'tcx>) { |
1327 | let target = Target::from_generic_param(generic_param); | |
6a06907d | 1328 | self.check_attributes(generic_param.hir_id, &generic_param.span, target, None); |
fc512014 XL |
1329 | intravisit::walk_generic_param(self, generic_param) |
1330 | } | |
1331 | ||
dfeec247 | 1332 | fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>) { |
e74abb32 | 1333 | let target = Target::from_trait_item(trait_item); |
6a06907d | 1334 | self.check_attributes(trait_item.hir_id(), &trait_item.span, target, None); |
e74abb32 XL |
1335 | intravisit::walk_trait_item(self, trait_item) |
1336 | } | |
1337 | ||
6a06907d XL |
1338 | fn visit_field_def(&mut self, struct_field: &'tcx hir::FieldDef<'tcx>) { |
1339 | self.check_attributes(struct_field.hir_id, &struct_field.span, Target::Field, None); | |
1340 | intravisit::walk_field_def(self, struct_field); | |
5869c6ff XL |
1341 | } |
1342 | ||
1343 | fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) { | |
6a06907d | 1344 | self.check_attributes(arm.hir_id, &arm.span, Target::Arm, None); |
5869c6ff XL |
1345 | intravisit::walk_arm(self, arm); |
1346 | } | |
1347 | ||
1b1a35ee | 1348 | fn visit_foreign_item(&mut self, f_item: &'tcx ForeignItem<'tcx>) { |
e74abb32 | 1349 | let target = Target::from_foreign_item(f_item); |
1b1a35ee | 1350 | self.check_attributes( |
6a06907d | 1351 | f_item.hir_id(), |
1b1a35ee XL |
1352 | &f_item.span, |
1353 | target, | |
1354 | Some(ItemLike::ForeignItem(f_item)), | |
1355 | ); | |
e74abb32 XL |
1356 | intravisit::walk_foreign_item(self, f_item) |
1357 | } | |
1358 | ||
dfeec247 | 1359 | fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) { |
74b04a01 | 1360 | let target = target_from_impl_item(self.tcx, impl_item); |
6a06907d | 1361 | self.check_attributes(impl_item.hir_id(), &impl_item.span, target, None); |
e74abb32 XL |
1362 | intravisit::walk_impl_item(self, impl_item) |
1363 | } | |
0531ce1d | 1364 | |
dfeec247 | 1365 | fn visit_stmt(&mut self, stmt: &'tcx hir::Stmt<'tcx>) { |
29967ef6 XL |
1366 | // When checking statements ignore expressions, they will be checked later. |
1367 | if let hir::StmtKind::Local(ref l) = stmt.kind { | |
6a06907d | 1368 | self.check_attributes(l.hir_id, &stmt.span, Target::Statement, None); |
29967ef6 | 1369 | } |
0531ce1d XL |
1370 | intravisit::walk_stmt(self, stmt) |
1371 | } | |
1372 | ||
dfeec247 | 1373 | fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) { |
29967ef6 XL |
1374 | let target = match expr.kind { |
1375 | hir::ExprKind::Closure(..) => Target::Closure, | |
1376 | _ => Target::Expression, | |
1377 | }; | |
1378 | ||
6a06907d | 1379 | self.check_attributes(expr.hir_id, &expr.span, target, None); |
0531ce1d | 1380 | intravisit::walk_expr(self, expr) |
b039eaaf | 1381 | } |
29967ef6 XL |
1382 | |
1383 | fn visit_variant( | |
1384 | &mut self, | |
1385 | variant: &'tcx hir::Variant<'tcx>, | |
1386 | generics: &'tcx hir::Generics<'tcx>, | |
1387 | item_id: HirId, | |
1388 | ) { | |
6a06907d | 1389 | self.check_attributes(variant.id, &variant.span, Target::Variant, None); |
29967ef6 XL |
1390 | intravisit::walk_variant(self, variant, generics, item_id) |
1391 | } | |
6a06907d XL |
1392 | |
1393 | fn visit_macro_def(&mut self, macro_def: &'tcx hir::MacroDef<'tcx>) { | |
1394 | self.check_attributes(macro_def.hir_id(), ¯o_def.span, Target::MacroDef, None); | |
1395 | intravisit::walk_macro_def(self, macro_def); | |
1396 | } | |
1397 | ||
1398 | fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) { | |
1399 | self.check_attributes(param.hir_id, ¶m.span, Target::Param, None); | |
1400 | ||
1401 | intravisit::walk_param(self, param); | |
1402 | } | |
b039eaaf SL |
1403 | } |
1404 | ||
dfeec247 | 1405 | fn is_c_like_enum(item: &Item<'_>) -> bool { |
e74abb32 | 1406 | if let ItemKind::Enum(ref def, _) = item.kind { |
dfeec247 | 1407 | for variant in def.variants { |
e1599b0c | 1408 | match variant.data { |
9fa01778 | 1409 | hir::VariantData::Unit(..) => { /* continue */ } |
e74abb32 | 1410 | _ => return false, |
ff7c6d11 XL |
1411 | } |
1412 | } | |
1413 | true | |
1414 | } else { | |
1415 | false | |
1416 | } | |
1417 | } | |
0731742a | 1418 | |
29967ef6 XL |
1419 | fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { |
1420 | const ATTRS_TO_CHECK: &[Symbol] = &[ | |
1421 | sym::macro_export, | |
1422 | sym::repr, | |
1423 | sym::path, | |
1424 | sym::automatically_derived, | |
1425 | sym::start, | |
1426 | sym::main, | |
1427 | ]; | |
1428 | ||
1429 | for attr in attrs { | |
1430 | for attr_to_check in ATTRS_TO_CHECK { | |
1431 | if tcx.sess.check_name(attr, *attr_to_check) { | |
1432 | tcx.sess | |
1433 | .struct_span_err( | |
1434 | attr.span, | |
1435 | &format!( | |
1436 | "`{}` attribute cannot be used at crate level", | |
1437 | attr_to_check.to_ident_string() | |
1438 | ), | |
1439 | ) | |
1440 | .emit(); | |
1441 | } | |
1442 | } | |
1443 | } | |
1444 | } | |
1445 | ||
5869c6ff XL |
1446 | fn check_invalid_macro_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { |
1447 | for attr in attrs { | |
1448 | if tcx.sess.check_name(attr, sym::inline) { | |
1449 | struct_span_err!( | |
1450 | tcx.sess, | |
1451 | attr.span, | |
1452 | E0518, | |
1453 | "attribute should be applied to function or closure", | |
1454 | ) | |
1455 | .span_label(attr.span, "not a function or closure") | |
1456 | .emit(); | |
1457 | } | |
1458 | } | |
1459 | } | |
1460 | ||
f035d41b | 1461 | fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalDefId) { |
5869c6ff XL |
1462 | let check_attr_visitor = &mut CheckAttrVisitor { tcx }; |
1463 | tcx.hir().visit_item_likes_in_module(module_def_id, &mut check_attr_visitor.as_deep_visitor()); | |
1464 | tcx.hir().visit_exported_macros_in_krate(check_attr_visitor); | |
1465 | check_invalid_macro_level_attr(tcx, tcx.hir().krate().non_exported_macro_attrs); | |
29967ef6 | 1466 | if module_def_id.is_top_level_module() { |
6a06907d | 1467 | check_attr_visitor.check_attributes(CRATE_HIR_ID, &DUMMY_SP, Target::Mod, None); |
29967ef6 XL |
1468 | check_invalid_crate_level_attr(tcx, tcx.hir().krate_attrs()); |
1469 | } | |
0731742a XL |
1470 | } |
1471 | ||
f035d41b | 1472 | pub(crate) fn provide(providers: &mut Providers) { |
dfeec247 | 1473 | *providers = Providers { check_mod_attrs, ..*providers }; |
0731742a | 1474 | } |