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
7 use rustc_middle::hir::map::Map;
8 use rustc_middle::ty::query::Providers;
9 use rustc_middle::ty::TyCtxt;
11 use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, NestedMetaItem};
12 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
13 use rustc_errors::{pluralize, struct_span_err, Applicability};
14 use rustc_feature::{AttributeType, BUILTIN_ATTRIBUTE_MAP};
16 use rustc_hir::def_id::LocalDefId;
17 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
18 use rustc_hir::{self, FnSig, ForeignItem, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID};
19 use rustc_hir::{MethodKind, Target};
20 use rustc_session::lint::builtin::{
21 CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, UNUSED_ATTRIBUTES,
23 use rustc_session::parse::feature_err;
24 use rustc_span::symbol::{sym, Symbol};
25 use rustc_span::{MultiSpan, Span, DUMMY_SP};
27 pub(crate) fn target_from_impl_item<'tcx>(
29 impl_item: &hir::ImplItem<'_>,
31 match impl_item.kind {
32 hir::ImplItemKind::Const(..) => Target::AssocConst,
33 hir::ImplItemKind::Fn(..) => {
34 let parent_hir_id = tcx.hir().get_parent_item(impl_item.hir_id());
35 let containing_item = tcx.hir().expect_item(parent_hir_id);
36 let containing_impl_is_for_trait = match &containing_item.kind {
37 hir::ItemKind::Impl(impl_) => impl_.of_trait.is_some(),
38 _ => bug!("parent of an ImplItem must be an Impl"),
40 if containing_impl_is_for_trait {
41 Target::Method(MethodKind::Trait { body: true })
43 Target::Method(MethodKind::Inherent)
46 hir::ImplItemKind::TyAlias(..) => Target::AssocTy,
50 #[derive(Clone, Copy)]
52 Item(&'tcx Item<'tcx>),
53 ForeignItem(&'tcx ForeignItem<'tcx>),
56 struct CheckAttrVisitor<'tcx> {
60 impl CheckAttrVisitor<'tcx> {
61 /// Checks any attribute.
67 item: Option<ItemLike<'_>>,
69 let mut doc_aliases = FxHashMap::default();
70 let mut is_valid = true;
71 let mut specified_inline = None;
72 let mut seen = FxHashSet::default();
73 let attrs = self.tcx.hir().attrs(hir_id);
75 let attr_is_valid = match attr.name_or_empty() {
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)
83 sym::doc => self.check_doc_attrs(
87 &mut specified_inline,
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),
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)
96 sym::allow_internal_unstable => {
97 self.check_allow_internal_unstable(hir_id, &attr, span, target, &attrs)
99 sym::rustc_allow_const_fn_unstable => {
100 self.check_rustc_allow_const_fn_unstable(hir_id, &attr, span, target)
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)
108 | sym::rustc_if_this_changed
109 | sym::rustc_then_this_would_need => self.check_rustc_dirty_clean(&attr),
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)
114 sym::must_not_suspend => self.check_must_not_suspend(&attr, span, target),
115 sym::rustc_const_unstable
116 | sym::rustc_const_stable
119 | sym::rustc_promotable => self.check_stability_promotable(&attr, span, target),
122 is_valid &= attr_is_valid;
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),
130 sym::deprecated | sym::rustc_deprecated => {
131 self.check_deprecated(hir_id, attr, span, target)
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])
141 sym::automatically_derived => {
142 self.check_generic_attr(hir_id, attr, target, &[Target::Impl])
144 sym::no_implicit_prelude => {
145 self.check_generic_attr(hir_id, attr, target, &[Target::Mod])
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))
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 \
160 ast::AttrStyle::Inner => "crate-level attribute should be in the root module",
162 lint.build(msg).emit()
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(
177 |lint| lint.build("unused attribute").emit(),
189 if matches!(target, Target::Closure | Target::Fn | Target::Method(_) | Target::ForeignFn) {
190 self.tcx.ensure().codegen_fn_attrs(self.tcx.hir().local_def_id(hir_id));
193 self.check_repr(attrs, span, target, item, hir_id);
194 self.check_used(attrs, target);
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| {
200 "`#[{}]` is ignored on struct fields, match arms and macro defs",
204 "this was previously accepted by the compiler but is \
205 being phased out; it will become a hard error in \
209 "see issue #80564 <https://github.com/rust-lang/rust/issues/80564> \
210 for more information",
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))
220 "this was previously accepted by the compiler but is \
221 being phased out; it will become a hard error in \
225 "see issue #80564 <https://github.com/rust-lang/rust/issues/80564> \
226 for more information",
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 {
237 | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true,
238 Target::Method(MethodKind::Trait { body: false }) | Target::ForeignFn => {
239 self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| {
240 lint.build("`#[inline]` is ignored on function prototypes").emit()
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
248 Target::AssocConst => {
249 self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| {
250 lint.build("`#[inline]` is ignored on constants")
252 "this was previously accepted by the compiler but is \
253 being phased out; it will become a hard error in \
257 "see issue #65833 <https://github.com/rust-lang/rust/issues/65833> \
258 for more information",
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");
274 "attribute should be applied to function or closure",
276 .span_label(*span, "not a function or closure")
283 fn check_generic_attr(
288 allowed_targets: &[Target],
290 if !allowed_targets.iter().any(|t| t == &target) {
291 let name = attr.name_or_empty();
292 let mut i = allowed_targets.iter();
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 {
304 b.push_str(&(allowed_target.to_string() + "s"));
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))
314 /// Checks if `#[naked]` is applied to a function definition.
315 fn check_naked(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool {
318 | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true,
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");
332 "attribute should be applied to a function definition",
334 .span_label(*span, "not a function definition")
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 {
345 | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true,
351 "attribute should be applied to a function definition",
353 .span_label(*span, "not a function definition")
360 /// Checks if a `#[track_caller]` is applied to a non-naked function. Returns `true` if valid.
361 fn check_track_caller(
365 attrs: &'hir [Attribute],
370 _ if attrs.iter().any(|attr| attr.has_name(sym::naked)) => {
375 "cannot use `#[track_caller]` with `#[naked]`",
380 Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => true,
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 => {
387 self.inline_attr_str_error_with_macro_def(hir_id, attr, "track_caller");
396 "attribute should be applied to function"
398 .span_label(*span, "not a function")
405 /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid. Returns `true` if valid.
406 fn check_non_exhaustive(
414 Target::Struct | Target::Enum | Target::Variant => true,
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");
428 "attribute can only be applied to a struct or enum"
430 .span_label(*span, "not a struct or enum")
437 /// Checks if the `#[marker]` attribute on an `item` is valid. Returns `true` if valid.
438 fn check_marker(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool {
440 Target::Trait => true,
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");
452 .struct_span_err(attr.span, "attribute can only be applied to a trait")
453 .span_label(*span, "not a trait")
460 /// Checks if the `#[target_feature]` attribute on `item` is valid. Returns `true` if valid.
461 fn check_target_feature(
470 | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true,
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")
477 "this was previously accepted by the compiler but is \
478 being phased out; it will become a hard error in \
481 .span_label(*span, "not a function")
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");
497 .struct_span_err(attr.span, "attribute should be applied to a function")
498 .span_label(*span, "not a function")
505 fn doc_attr_str_error(&self, meta: &NestedMetaItem, attr_name: &str) {
510 &format!("doc {0} attribute expects a string: #[doc({0} = \"a\")]", attr_name),
515 fn check_doc_alias_value(
517 meta: &NestedMetaItem,
522 aliases: &mut FxHashMap<String, Span>,
525 let err_fn = move |span: Span, msg: &str| {
529 "`#[doc(alias{})]` {}",
530 if is_list { "(\"...\")" } else { " = \"...\"" },
536 if doc_alias.is_empty() {
538 meta.name_value_literal_span().unwrap_or_else(|| meta.span()),
539 "attribute cannot have empty value",
543 doc_alias.chars().find(|&c| c == '"' || c == '\'' || (c.is_whitespace() && c != ' '))
545 self.tcx.sess.span_err(
546 meta.name_value_literal_span().unwrap_or_else(|| meta.span()),
548 "{:?} character isn't allowed in `#[doc(alias{})]`",
550 if is_list { "(\"...\")" } else { " = \"...\"" },
555 if doc_alias.starts_with(' ') || doc_alias.ends_with(' ') {
557 meta.name_value_literal_span().unwrap_or_else(|| meta.span()),
558 "cannot start or end with ' '",
561 if let Some(err) = match target {
562 Target::Impl => Some("implementation block"),
563 Target::ForeignMod => Some("extern block"),
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")
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 {
579 ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) => Some(err),
583 // we check the validity of params elsewhere
584 Target::Param => return false,
587 return err_fn(meta.span(), &format!("isn't allowed on {}", err));
589 let item_name = self.tcx.hir().name(hir_id);
590 if &*item_name.as_str() == doc_alias {
591 return err_fn(meta.span(), "is the same as the item's name");
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")
606 meta: &NestedMetaItem,
609 aliases: &mut FxHashMap<String, Span>,
611 if let Some(values) = meta.meta_item_list() {
615 Some(l) => match l.kind {
616 LitKind::Str(s, _) => {
617 if !self.check_doc_alias_value(
633 "`#[doc(alias(\"a\"))]` expects string literals",
644 "`#[doc(alias(\"a\"))]` expects string literals",
652 } else if let Some(doc_alias) = meta.value_str().map(|s| s.to_string()) {
653 self.check_doc_alias_value(meta, &doc_alias, hir_id, target, false, aliases)
659 "doc alias attribute expects a string `#[doc(alias = \"a\")]` or a list of \
660 strings `#[doc(alias(\"a\", \"b\"))]`",
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");
673 match self.tcx.hir().find(hir_id).and_then(|node| match node {
674 hir::Node::Item(item) => Some(&item.kind),
677 Some(ItemKind::Mod(ref module)) => {
678 if !module.item_ids.is_empty() {
683 "`#[doc(keyword = \"...\")]` can only be used on empty modules",
694 "`#[doc(keyword = \"...\")]` can only be used on modules",
700 if !rustc_lexer::is_ident(&doc_keyword) {
704 meta.name_value_literal_span().unwrap_or_else(|| meta.span()),
705 &format!("`{}` is not a valid identifier", doc_keyword),
713 /// Checks `#[doc(inline)]`/`#[doc(no_inline)]` attributes. Returns `true` if valid.
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.
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.
725 meta: &NestedMetaItem,
728 specified_inline: &mut Option<(bool, Span)>,
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(
738 String::from("...conflicts with this attribute"),
742 .struct_span_err(spans, "conflicting doc inlining attributes")
743 .help("remove one of the conflicting attributes")
749 *specified_inline = Some((do_inline, meta.span()));
753 self.tcx.struct_span_lint_hir(
754 INVALID_DOC_ATTRIBUTES,
758 let mut err = lint.build(
759 "this attribute can only be applied to a `use` item",
761 err.span_label(meta.span(), "only applicable on `use` items");
762 if attr.style == AttrStyle::Outer {
764 self.tcx.hir().span(hir_id),
768 err.note("read https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#inline-and-no_inline for more information")
776 /// Checks that an attribute is *not* used at the crate level. Returns `true` if valid.
777 fn check_attr_not_crate_level(
779 meta: &NestedMetaItem,
783 if CRATE_HIR_ID == hir_id {
789 "`#![doc({} = \"...\")]` isn't allowed as a crate-level attribute",
799 /// Checks that an attribute is used at the crate level. Returns `true` if valid.
800 fn check_attr_crate_level(
803 meta: &NestedMetaItem,
806 if hir_id != CRATE_HIR_ID {
807 self.tcx.struct_span_lint_hir(
808 INVALID_DOC_ATTRIBUTES,
812 let mut err = lint.build(
813 "this attribute can only be applied at the crate level",
815 if attr.style == AttrStyle::Outer && self.tcx.hir().get_parent_item(hir_id) == CRATE_HIR_ID {
817 self.tcx.sess.source_map().span_to_snippet(attr.span)
820 err.span_suggestion_verbose(
822 "to apply to the crate, use an inner attribute",
824 Applicability::MaybeIncorrect,
829 "to apply to the crate, use an inner attribute",
833 err.note("read https://doc.rust-lang.org/nightly/rustdoc/the-doc-attribute.html#at-the-crate-level for more information")
842 /// Checks that `doc(test(...))` attribute contains only valid attributes. Returns `true` if
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 => {}
851 self.tcx.struct_span_lint_hir(
852 INVALID_DOC_ATTRIBUTES,
857 "unknown `doc(test)` attribute `{}`",
858 rustc_ast_pretty::pprust::path_to_string(
859 &i_meta.meta_item().unwrap().path
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();
878 /// Runs various checks on `#[doc]` attributes. Returns `true` if valid.
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.
883 /// [`check_doc_inline`]: Self::check_doc_inline
889 specified_inline: &mut Option<(bool, Span)>,
890 aliases: &mut FxHashMap<String, Span>,
892 let mut is_valid = true;
894 if let Some(list) = attr.meta().and_then(|mi| mi.meta_item_list().map(|l| l.to_vec())) {
896 if let Some(i_meta) = meta.meta_item() {
897 match i_meta.name_or_empty() {
899 if !self.check_attr_not_crate_level(&meta, hir_id, "alias")
900 || !self.check_doc_alias(&meta, hir_id, target, aliases) =>
906 if !self.check_attr_not_crate_level(&meta, hir_id, "keyword")
907 || !self.check_doc_keyword(&meta, hir_id) =>
912 sym::html_favicon_url
914 | sym::html_playground_url
915 | sym::issue_tracker_base_url
917 | sym::html_no_source
919 if !self.check_attr_crate_level(&attr, &meta, hir_id) =>
924 sym::inline | sym::no_inline
925 if !self.check_doc_inline(
936 // no_default_passes: deprecated
937 // passes: deprecated
938 // plugins: removed, but rustdoc warns about it itself
943 | sym::html_favicon_url
945 | sym::html_no_source
946 | sym::html_playground_url
949 | sym::issue_tracker_base_url
952 | sym::no_default_passes
959 if !self.check_test_attr(&meta, hir_id) {
965 if !self.tcx.features().doc_primitive {
966 self.tcx.struct_span_lint_hir(
967 INVALID_DOC_ATTRIBUTES,
971 let mut diag = lint.build(
972 "`doc(primitive)` should never have been stable",
981 self.tcx.struct_span_lint_hir(
982 INVALID_DOC_ATTRIBUTES,
986 let mut diag = lint.build(&format!(
987 "unknown `doc` attribute `{}`",
988 rustc_ast_pretty::pprust::path_to_string(&i_meta.path),
990 if i_meta.has_name(sym::spotlight) {
992 "`doc(spotlight)` was renamed to `doc(notable_trait)`",
994 diag.span_suggestion_short(
996 "use `notable_trait` instead",
997 String::from("notable_trait"),
998 Applicability::MachineApplicable,
1000 diag.note("`doc(spotlight)` is now a no-op");
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
1008 Applicability::MaybeIncorrect
1010 let inner = if attr.style == AttrStyle::Inner {
1015 diag.span_suggestion(
1016 attr.meta().unwrap().span,
1017 "use `doc = include_str!` instead",
1019 "#{}[doc = include_str!(\"{}\")]",
1033 self.tcx.struct_span_lint_hir(
1034 INVALID_DOC_ATTRIBUTES,
1038 lint.build(&"invalid `doc` attribute").emit();
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 {
1052 Target::Struct | Target::Enum | Target::Union | Target::Trait => true,
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")
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) {
1067 Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => {}
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");
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")
1081 "this was previously accepted by the compiler but is \
1082 being phased out; it will become a hard error in \
1085 .span_label(*span, "not a function")
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) {
1095 Target::ForeignFn | Target::ForeignStatic => {}
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");
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| {
1108 lint.build("attribute should be applied to a foreign function or static");
1110 "this was previously accepted by the compiler but is \
1111 being phased out; it will become a hard error in \
1116 if let Target::ForeignMod = target {
1117 if let Some(value) = attr.value_str() {
1120 &format!(r#"try `#[link(name = "{}")]` instead"#, value),
1123 diag.span_help(attr.span, r#"try `#[link(name = "...")]` instead"#);
1127 diag.span_label(*span, "not a foreign function or static");
1134 /// Checks if `#[no_link]` is applied to an `extern crate`. Returns `true` if valid.
1135 fn check_no_link(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool {
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");
1151 "attribute should be applied to an `extern crate` item",
1153 .span_label(*span, "not an `extern crate` item")
1160 fn is_impl_item(&self, hir_id: HirId) -> bool {
1161 matches!(self.tcx.hir().get(hir_id), hir::Node::ImplItem(..))
1164 /// Checks if `#[export_name]` is applied to a function or static. Returns `true` if valid.
1165 fn check_export_name(
1173 Target::Static | Target::Fn => true,
1174 Target::Method(..) if self.is_impl_item(hir_id) => true,
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");
1188 "attribute should be applied to a free function, impl method or static",
1190 .span_label(*span, "not a free function, impl method or static")
1197 fn check_rustc_layout_scalar_valid_range(
1203 if target != Target::Struct {
1206 .struct_span_err(attr.span, "attribute should be applied to a struct")
1207 .span_label(*span, "not a struct")
1212 let list = match attr.meta_item_list() {
1213 None => return false,
1217 if matches!(&list[..], &[NestedMetaItem::Literal(Lit { kind: LitKind::Int(..), .. })]) {
1222 .struct_span_err(attr.span, "expected exactly one integer literal argument")
1228 /// Checks if `#[rustc_legacy_const_generics]` is applied to a function and has a valid argument.
1229 fn check_rustc_legacy_const_generics(
1234 item: Option<ItemLike<'_>>,
1236 let is_function = matches!(target, Target::Fn | Target::Method(..));
1240 .struct_span_err(attr.span, "attribute should be applied to a function")
1241 .span_label(*span, "not a function")
1246 let list = match attr.meta_item_list() {
1247 // The attribute form is validated on AST.
1248 None => return false,
1252 let (decl, generics) = match item {
1253 Some(ItemLike::Item(Item {
1254 kind: ItemKind::Fn(FnSig { decl, .. }, generics, _),
1256 })) => (decl, generics),
1257 _ => bug!("should be a function item"),
1260 for param in generics.params {
1262 hir::GenericParamKind::Const { .. } => {}
1268 "#[rustc_legacy_const_generics] functions must \
1269 only have const generics",
1271 .span_label(param.span, "non-const generic parameter")
1278 if list.len() != generics.params.len() {
1283 "#[rustc_legacy_const_generics] must have one index for each generic parameter",
1285 .span_label(generics.span, "generic parameters")
1290 let arg_count = decl.inputs.len() as u128 + generics.params.len() as u128;
1291 let mut invalid_args = vec![];
1293 if let Some(LitKind::Int(val, _)) = meta.literal().map(|lit| &lit.kind) {
1294 if *val >= arg_count {
1295 let span = meta.span();
1298 .struct_span_err(span, "index exceeds number of arguments")
1302 "there {} only {} argument{}",
1303 if arg_count != 1 { "are" } else { "is" },
1305 pluralize!(arg_count)
1312 invalid_args.push(meta.span());
1316 if !invalid_args.is_empty() {
1319 .struct_span_err(invalid_args, "arguments should be non-negative integers")
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 {
1335 .struct_span_err(attr.span, "attribute requires -Z query-dep-graph to be enabled")
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) {
1344 Target::Static | Target::Fn | Target::Method(..) => {}
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");
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")
1358 "this was previously accepted by the compiler but is \
1359 being phased out; it will become a hard error in \
1362 .span_label(*span, "not a function or static")
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) {
1372 Target::Static | Target::Fn => {}
1373 Target::Method(..) if self.is_impl_item(hir_id) => {}
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");
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!(),
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 {}",
1396 "this was previously accepted by the compiler but is \
1397 being phased out; it will become a hard error in \
1400 .span_label(*span, format!("foreign {}", foreign_item_kind))
1401 .note("symbol names in extern blocks are not mangled")
1404 "remove this attribute",
1406 Applicability::MachineApplicable,
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| {
1416 "attribute should be applied to a free function, impl method or static",
1419 "this was previously accepted by the compiler but is \
1420 being phased out; it will become a hard error in \
1423 .span_label(*span, "not a free function, impl method or static")
1430 /// Checks if the `#[repr]` attributes on `item` are valid.
1433 attrs: &'hir [Attribute],
1436 item: Option<ItemLike<'_>>,
1439 // Extract the names of all repr hints, e.g., [foo, bar, align] for:
1442 // #[repr(bar, align(8))]
1444 let hints: Vec<_> = attrs
1446 .filter(|attr| attr.has_name(sym::repr))
1447 .filter_map(|attr| attr.meta_item_list())
1451 let mut int_reprs = 0;
1452 let mut is_c = false;
1453 let mut is_simd = false;
1454 let mut is_transparent = false;
1456 for hint in &hints {
1457 if !hint.is_meta_item() {
1462 "meta item in `repr` must be an identifier"
1468 let (article, allowed_targets) = match hint.name_or_empty() {
1472 Target::Struct | Target::Union | Target::Enum => continue,
1473 _ => ("a", "struct, enum, or union"),
1477 if let (Target::Fn, true) = (target, !self.tcx.features().fn_align) {
1479 &self.tcx.sess.parse_sess,
1482 "`repr(align)` attributes on functions are unstable",
1488 Target::Struct | Target::Union | Target::Enum | Target::Fn => continue,
1489 _ => ("a", "struct, enum, function, or union"),
1493 if target != Target::Struct && target != Target::Union {
1494 ("a", "struct or union")
1501 if target != Target::Struct {
1507 sym::transparent => {
1508 is_transparent = true;
1510 Target::Struct | Target::Union | Target::Enum => continue,
1511 _ => ("a", "struct, enum, or union"),
1515 if !self.tcx.features().enabled(sym::no_niche) {
1517 &self.tcx.sess.parse_sess,
1520 "the attribute `repr(no_niche)` is currently unstable",
1525 Target::Struct | Target::Enum => continue,
1526 _ => ("a", "struct or enum"),
1542 if target != Target::Enum {
1553 "unrecognized representation hint"
1566 &format!("attribute should be applied to {} {}", article, allowed_targets)
1568 .span_label(*span, &format!("not {} {}", article, allowed_targets))
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.
1574 let hint_spans = hints.iter().map(|hint| hint.span());
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 {
1580 let hint_spans: Vec<_> = hint_spans.clone().collect();
1585 "transparent {} cannot have other repr hints",
1590 // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8)
1592 || (is_simd && is_c)
1595 && item.map_or(false, |item| {
1596 if let ItemLike::Item(item) = item {
1597 return is_c_like_enum(item);
1602 self.tcx.struct_span_lint_hir(
1603 CONFLICTING_REPR_HINTS,
1605 hint_spans.collect::<Vec<Span>>(),
1607 lint.build("conflicting representation hints")
1608 .code(rustc_errors::error_code!(E0566))
1615 fn check_used(&self, attrs: &'hir [Attribute], target: Target) {
1617 if attr.has_name(sym::used) && target != Target::Static {
1620 .span_err(attr.span, "attribute must be applied to a `static` variable");
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(
1633 attrs: &[Attribute],
1635 debug!("Checking target: {:?}", target);
1639 if self.tcx.sess.is_proc_macro_attr(attr) {
1640 debug!("Is proc macro attr");
1644 debug!("Is not proc macro attr");
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(
1656 "allow_internal_unstable",
1663 .struct_span_err(attr.span, "attribute should be applied to a macro")
1664 .span_label(*span, "not a macro")
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(
1681 Target::Fn | Target::Method(_)
1682 if self.tcx.is_const_fn_raw(self.tcx.hir().local_def_id(hir_id)) =>
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");
1697 .struct_span_err(attr.span, "attribute should be applied to `const fn`")
1698 .span_label(*span, "not a `const fn`")
1705 /// default_method_body_is_const should only be applied to trait methods with default bodies.
1706 fn check_default_method_body_is_const(
1713 Target::Method(MethodKind::Trait { body: true }) => true,
1719 "attribute should be applied to a trait method with body",
1721 .span_label(*span, "not a trait method or missing a body")
1728 fn check_stability_promotable(&self, attr: &Attribute, _span: &Span, target: Target) -> bool {
1730 Target::Expression => {
1733 .struct_span_err(attr.span, "attribute cannot be applied to an expression")
1741 fn check_deprecated(&self, hir_id: HirId, attr: &Attribute, _span: &Span, target: 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();
1752 fn check_macro_use(&self, hir_id: HirId, attr: &Attribute, target: Target) {
1753 let name = attr.name_or_empty();
1755 Target::ExternCrate | Target::Mod => {}
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"
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| {
1770 lint.build("`#[macro_export]` only has an effect on macro definitions").emit();
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();
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();
1794 impl Visitor<'tcx> for CheckAttrVisitor<'tcx> {
1795 type Map = Map<'tcx>;
1797 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
1798 NestedVisitorMap::OnlyBodies(self.tcx.hir())
1801 fn visit_item(&mut self, item: &'tcx Item<'tcx>) {
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);
1812 let target = Target::from_item(item);
1813 self.check_attributes(item.hir_id(), &item.span, target, Some(ItemLike::Item(item)));
1814 intravisit::walk_item(self, item)
1817 fn visit_generic_param(&mut self, generic_param: &'tcx hir::GenericParam<'tcx>) {
1818 let target = Target::from_generic_param(generic_param);
1819 self.check_attributes(generic_param.hir_id, &generic_param.span, target, None);
1820 intravisit::walk_generic_param(self, generic_param)
1823 fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>) {
1824 let target = Target::from_trait_item(trait_item);
1825 self.check_attributes(trait_item.hir_id(), &trait_item.span, target, None);
1826 intravisit::walk_trait_item(self, trait_item)
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);
1834 fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) {
1835 self.check_attributes(arm.hir_id, &arm.span, Target::Arm, None);
1836 intravisit::walk_arm(self, arm);
1839 fn visit_foreign_item(&mut self, f_item: &'tcx ForeignItem<'tcx>) {
1840 let target = Target::from_foreign_item(f_item);
1841 self.check_attributes(
1845 Some(ItemLike::ForeignItem(f_item)),
1847 intravisit::walk_foreign_item(self, f_item)
1850 fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
1851 let target = target_from_impl_item(self.tcx, impl_item);
1852 self.check_attributes(impl_item.hir_id(), &impl_item.span, target, None);
1853 intravisit::walk_impl_item(self, impl_item)
1856 fn visit_stmt(&mut self, stmt: &'tcx hir::Stmt<'tcx>) {
1857 // When checking statements ignore expressions, they will be checked later.
1858 if let hir::StmtKind::Local(ref l) = stmt.kind {
1859 self.check_attributes(l.hir_id, &stmt.span, Target::Statement, None);
1861 intravisit::walk_stmt(self, stmt)
1864 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1865 let target = match expr.kind {
1866 hir::ExprKind::Closure(..) => Target::Closure,
1867 _ => Target::Expression,
1870 self.check_attributes(expr.hir_id, &expr.span, target, None);
1871 intravisit::walk_expr(self, expr)
1876 variant: &'tcx hir::Variant<'tcx>,
1877 generics: &'tcx hir::Generics<'tcx>,
1880 self.check_attributes(variant.id, &variant.span, Target::Variant, None);
1881 intravisit::walk_variant(self, variant, generics, item_id)
1884 fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) {
1885 self.check_attributes(param.hir_id, ¶m.span, Target::Param, None);
1887 intravisit::walk_param(self, param);
1891 fn is_c_like_enum(item: &Item<'_>) -> bool {
1892 if let ItemKind::Enum(ref def, _) = item.kind {
1893 for variant in def.variants {
1894 match variant.data {
1895 hir::VariantData::Unit(..) => { /* continue */ }
1905 fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
1906 const ATTRS_TO_CHECK: &[Symbol] = &[
1910 sym::automatically_derived,
1916 for attr_to_check in ATTRS_TO_CHECK {
1917 if attr.has_name(*attr_to_check) {
1922 "`{}` attribute cannot be used at crate level",
1923 attr_to_check.to_ident_string()
1932 fn check_non_exported_macro_for_invalid_attrs(tcx: TyCtxt<'_>, item: &Item<'_>) {
1933 let attrs = tcx.hir().attrs(item.hir_id());
1936 if attr.has_name(sym::inline) {
1941 "attribute should be applied to function or closure",
1943 .span_label(attr.span, "not a function or closure")
1949 fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
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());
1952 if module_def_id.is_top_level_module() {
1953 check_attr_visitor.check_attributes(CRATE_HIR_ID, &DUMMY_SP, Target::Mod, None);
1954 check_invalid_crate_level_attr(tcx, tcx.hir().krate_attrs());
1958 pub(crate) fn provide(providers: &mut Providers) {
1959 *providers = Providers { check_mod_attrs, ..*providers };