| //! This module implements some validity checks for attributes. |
| //! In particular it verifies that `#[inline]` and `#[repr]` attributes are |
| //! attached to items that actually support them and if there are |
| //! conflicts between multiple such attributes attached to the same |
| //! item. |
| |
| use rustc_middle::hir::map::Map; |
| use rustc_middle::ty::query::Providers; |
| use rustc_middle::ty::TyCtxt; |
| |
| use rustc_ast::{Attribute, LitKind, NestedMetaItem}; |
| use rustc_errors::{pluralize, struct_span_err}; |
| use rustc_hir as hir; |
| use rustc_hir::def_id::LocalDefId; |
| use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; |
| use rustc_hir::{ |
| self, FnSig, ForeignItem, ForeignItemKind, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID, |
| }; |
| use rustc_hir::{MethodKind, Target}; |
| use rustc_session::lint::builtin::{CONFLICTING_REPR_HINTS, UNUSED_ATTRIBUTES}; |
| use rustc_session::parse::feature_err; |
| use rustc_span::symbol::{sym, Symbol}; |
| use rustc_span::{Span, DUMMY_SP}; |
| |
| pub(crate) fn target_from_impl_item<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| impl_item: &hir::ImplItem<'_>, |
| ) -> Target { |
| match impl_item.kind { |
| hir::ImplItemKind::Const(..) => Target::AssocConst, |
| hir::ImplItemKind::Fn(..) => { |
| let parent_hir_id = tcx.hir().get_parent_item(impl_item.hir_id); |
| let containing_item = tcx.hir().expect_item(parent_hir_id); |
| let containing_impl_is_for_trait = match &containing_item.kind { |
| hir::ItemKind::Impl { ref of_trait, .. } => of_trait.is_some(), |
| _ => bug!("parent of an ImplItem must be an Impl"), |
| }; |
| if containing_impl_is_for_trait { |
| Target::Method(MethodKind::Trait { body: true }) |
| } else { |
| Target::Method(MethodKind::Inherent) |
| } |
| } |
| hir::ImplItemKind::TyAlias(..) => Target::AssocTy, |
| } |
| } |
| |
| #[derive(Clone, Copy)] |
| enum ItemLike<'tcx> { |
| Item(&'tcx Item<'tcx>), |
| ForeignItem(&'tcx ForeignItem<'tcx>), |
| } |
| |
| struct CheckAttrVisitor<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| } |
| |
| impl CheckAttrVisitor<'tcx> { |
| /// Checks any attribute. |
| fn check_attributes( |
| &self, |
| hir_id: HirId, |
| attrs: &'hir [Attribute], |
| span: &Span, |
| target: Target, |
| item: Option<ItemLike<'_>>, |
| ) { |
| let mut is_valid = true; |
| for attr in attrs { |
| is_valid &= if self.tcx.sess.check_name(attr, sym::inline) { |
| self.check_inline(hir_id, attr, span, target) |
| } else if self.tcx.sess.check_name(attr, sym::non_exhaustive) { |
| self.check_non_exhaustive(attr, span, target) |
| } else if self.tcx.sess.check_name(attr, sym::marker) { |
| self.check_marker(attr, span, target) |
| } else if self.tcx.sess.check_name(attr, sym::target_feature) { |
| self.check_target_feature(hir_id, attr, span, target) |
| } else if self.tcx.sess.check_name(attr, sym::track_caller) { |
| self.check_track_caller(&attr.span, attrs, span, target) |
| } else if self.tcx.sess.check_name(attr, sym::doc) { |
| self.check_doc_alias(attr, hir_id, target) |
| } else if self.tcx.sess.check_name(attr, sym::no_link) { |
| self.check_no_link(&attr, span, target) |
| } else if self.tcx.sess.check_name(attr, sym::export_name) { |
| self.check_export_name(&attr, span, target) |
| } else if self.tcx.sess.check_name(attr, sym::rustc_args_required_const) { |
| self.check_rustc_args_required_const(&attr, span, target, item) |
| } else { |
| // lint-only checks |
| if self.tcx.sess.check_name(attr, sym::cold) { |
| self.check_cold(hir_id, attr, span, target); |
| } else if self.tcx.sess.check_name(attr, sym::link_name) { |
| self.check_link_name(hir_id, attr, span, target); |
| } else if self.tcx.sess.check_name(attr, sym::link_section) { |
| self.check_link_section(hir_id, attr, span, target); |
| } else if self.tcx.sess.check_name(attr, sym::no_mangle) { |
| self.check_no_mangle(hir_id, attr, span, target); |
| } |
| true |
| }; |
| } |
| |
| if !is_valid { |
| return; |
| } |
| |
| if matches!(target, Target::Closure | Target::Fn | Target::Method(_) | Target::ForeignFn) { |
| self.tcx.ensure().codegen_fn_attrs(self.tcx.hir().local_def_id(hir_id)); |
| } |
| |
| self.check_repr(attrs, span, target, item, hir_id); |
| self.check_used(attrs, target); |
| } |
| |
| /// Checks if an `#[inline]` is applied to a function or a closure. Returns `true` if valid. |
| fn check_inline(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) -> bool { |
| match target { |
| Target::Fn |
| | Target::Closure |
| | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, |
| Target::Method(MethodKind::Trait { body: false }) | Target::ForeignFn => { |
| self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
| lint.build("`#[inline]` is ignored on function prototypes").emit() |
| }); |
| true |
| } |
| // FIXME(#65833): We permit associated consts to have an `#[inline]` attribute with |
| // just a lint, because we previously erroneously allowed it and some crates used it |
| // accidentally, to to be compatible with crates depending on them, we can't throw an |
| // error here. |
| Target::AssocConst => { |
| self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
| lint.build("`#[inline]` is ignored on constants") |
| .warn( |
| "this was previously accepted by the compiler but is \ |
| being phased out; it will become a hard error in \ |
| a future release!", |
| ) |
| .note( |
| "see issue #65833 <https://github.com/rust-lang/rust/issues/65833> \ |
| for more information", |
| ) |
| .emit(); |
| }); |
| true |
| } |
| _ => { |
| struct_span_err!( |
| self.tcx.sess, |
| attr.span, |
| E0518, |
| "attribute should be applied to function or closure", |
| ) |
| .span_label(*span, "not a function or closure") |
| .emit(); |
| false |
| } |
| } |
| } |
| |
| /// Checks if a `#[track_caller]` is applied to a non-naked function. Returns `true` if valid. |
| fn check_track_caller( |
| &self, |
| attr_span: &Span, |
| attrs: &'hir [Attribute], |
| span: &Span, |
| target: Target, |
| ) -> bool { |
| match target { |
| _ if self.tcx.sess.contains_name(attrs, sym::naked) => { |
| struct_span_err!( |
| self.tcx.sess, |
| *attr_span, |
| E0736, |
| "cannot use `#[track_caller]` with `#[naked]`", |
| ) |
| .emit(); |
| false |
| } |
| Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => true, |
| _ => { |
| struct_span_err!( |
| self.tcx.sess, |
| *attr_span, |
| E0739, |
| "attribute should be applied to function" |
| ) |
| .span_label(*span, "not a function") |
| .emit(); |
| false |
| } |
| } |
| } |
| |
| /// Checks if the `#[non_exhaustive]` attribute on an `item` is valid. Returns `true` if valid. |
| fn check_non_exhaustive(&self, attr: &Attribute, span: &Span, target: Target) -> bool { |
| match target { |
| Target::Struct | Target::Enum | Target::Variant => true, |
| _ => { |
| struct_span_err!( |
| self.tcx.sess, |
| attr.span, |
| E0701, |
| "attribute can only be applied to a struct or enum" |
| ) |
| .span_label(*span, "not a struct or enum") |
| .emit(); |
| false |
| } |
| } |
| } |
| |
| /// Checks if the `#[marker]` attribute on an `item` is valid. Returns `true` if valid. |
| fn check_marker(&self, attr: &Attribute, span: &Span, target: Target) -> bool { |
| match target { |
| Target::Trait => true, |
| _ => { |
| self.tcx |
| .sess |
| .struct_span_err(attr.span, "attribute can only be applied to a trait") |
| .span_label(*span, "not a trait") |
| .emit(); |
| false |
| } |
| } |
| } |
| |
| /// Checks if the `#[target_feature]` attribute on `item` is valid. Returns `true` if valid. |
| fn check_target_feature( |
| &self, |
| hir_id: HirId, |
| attr: &Attribute, |
| span: &Span, |
| target: Target, |
| ) -> bool { |
| match target { |
| Target::Fn |
| | Target::Method(MethodKind::Trait { body: true } | MethodKind::Inherent) => true, |
| // FIXME: #[target_feature] was previously erroneously allowed on statements and some |
| // crates used this, so only emit a warning. |
| Target::Statement => { |
| self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
| lint.build("attribute should be applied to a function") |
| .warn( |
| "this was previously accepted by the compiler but is \ |
| being phased out; it will become a hard error in \ |
| a future release!", |
| ) |
| .span_label(*span, "not a function") |
| .emit(); |
| }); |
| true |
| } |
| _ => { |
| self.tcx |
| .sess |
| .struct_span_err(attr.span, "attribute should be applied to a function") |
| .span_label(*span, "not a function") |
| .emit(); |
| false |
| } |
| } |
| } |
| |
| fn doc_alias_str_error(&self, meta: &NestedMetaItem) { |
| self.tcx |
| .sess |
| .struct_span_err( |
| meta.span(), |
| "doc alias attribute expects a string: #[doc(alias = \"0\")]", |
| ) |
| .emit(); |
| } |
| |
| fn check_doc_alias(&self, attr: &Attribute, hir_id: HirId, target: Target) -> bool { |
| if let Some(mi) = attr.meta() { |
| if let Some(list) = mi.meta_item_list() { |
| for meta in list { |
| if meta.has_name(sym::alias) { |
| if !meta.is_value_str() { |
| self.doc_alias_str_error(meta); |
| return false; |
| } |
| let doc_alias = |
| meta.value_str().map(|s| s.to_string()).unwrap_or_else(String::new); |
| if doc_alias.is_empty() { |
| self.doc_alias_str_error(meta); |
| return false; |
| } |
| if let Some(c) = doc_alias |
| .chars() |
| .find(|&c| c == '"' || c == '\'' || (c.is_whitespace() && c != ' ')) |
| { |
| self.tcx |
| .sess |
| .struct_span_err( |
| meta.span(), |
| &format!( |
| "{:?} character isn't allowed in `#[doc(alias = \"...\")]`", |
| c, |
| ), |
| ) |
| .emit(); |
| return false; |
| } |
| if doc_alias.starts_with(' ') || doc_alias.ends_with(' ') { |
| self.tcx |
| .sess |
| .struct_span_err( |
| meta.span(), |
| "`#[doc(alias = \"...\")]` cannot start or end with ' '", |
| ) |
| .emit(); |
| return false; |
| } |
| if let Some(err) = match target { |
| Target::Impl => Some("implementation block"), |
| Target::ForeignMod => Some("extern block"), |
| Target::AssocTy => { |
| let parent_hir_id = self.tcx.hir().get_parent_item(hir_id); |
| let containing_item = self.tcx.hir().expect_item(parent_hir_id); |
| if Target::from_item(containing_item) == Target::Impl { |
| Some("type alias in implementation block") |
| } else { |
| None |
| } |
| } |
| Target::AssocConst => { |
| let parent_hir_id = self.tcx.hir().get_parent_item(hir_id); |
| let containing_item = self.tcx.hir().expect_item(parent_hir_id); |
| // We can't link to trait impl's consts. |
| let err = "associated constant in trait implementation block"; |
| match containing_item.kind { |
| ItemKind::Impl { of_trait: Some(_), .. } => Some(err), |
| _ => None, |
| } |
| } |
| _ => None, |
| } { |
| self.tcx |
| .sess |
| .struct_span_err( |
| meta.span(), |
| &format!("`#[doc(alias = \"...\")]` isn't allowed on {}", err), |
| ) |
| .emit(); |
| return false; |
| } |
| if CRATE_HIR_ID == hir_id { |
| self.tcx |
| .sess |
| .struct_span_err( |
| meta.span(), |
| "`#![doc(alias = \"...\")]` isn't allowed as a crate \ |
| level attribute", |
| ) |
| .emit(); |
| return false; |
| } |
| } |
| } |
| } |
| } |
| true |
| } |
| |
| /// Checks if `#[cold]` is applied to a non-function. Returns `true` if valid. |
| fn check_cold(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { |
| match target { |
| Target::Fn | Target::Method(..) | Target::ForeignFn | Target::Closure => {} |
| _ => { |
| // FIXME: #[cold] was previously allowed on non-functions and some crates used |
| // this, so only emit a warning. |
| self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
| lint.build("attribute should be applied to a function") |
| .warn( |
| "this was previously accepted by the compiler but is \ |
| being phased out; it will become a hard error in \ |
| a future release!", |
| ) |
| .span_label(*span, "not a function") |
| .emit(); |
| }); |
| } |
| } |
| } |
| |
| /// Checks if `#[link_name]` is applied to an item other than a foreign function or static. |
| fn check_link_name(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { |
| match target { |
| Target::ForeignFn | Target::ForeignStatic => {} |
| _ => { |
| // FIXME: #[cold] was previously allowed on non-functions/statics and some crates |
| // used this, so only emit a warning. |
| self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
| let mut diag = |
| lint.build("attribute should be applied to a foreign function or static"); |
| diag.warn( |
| "this was previously accepted by the compiler but is \ |
| being phased out; it will become a hard error in \ |
| a future release!", |
| ); |
| |
| // See issue #47725 |
| if let Target::ForeignMod = target { |
| if let Some(value) = attr.value_str() { |
| diag.span_help( |
| attr.span, |
| &format!(r#"try `#[link(name = "{}")]` instead"#, value), |
| ); |
| } else { |
| diag.span_help(attr.span, r#"try `#[link(name = "...")]` instead"#); |
| } |
| } |
| |
| diag.span_label(*span, "not a foreign function or static"); |
| diag.emit(); |
| }); |
| } |
| } |
| } |
| |
| /// Checks if `#[no_link]` is applied to an `extern crate`. Returns `true` if valid. |
| fn check_no_link(&self, attr: &Attribute, span: &Span, target: Target) -> bool { |
| if target == Target::ExternCrate { |
| true |
| } else { |
| self.tcx |
| .sess |
| .struct_span_err(attr.span, "attribute should be applied to an `extern crate` item") |
| .span_label(*span, "not an `extern crate` item") |
| .emit(); |
| false |
| } |
| } |
| |
| /// Checks if `#[export_name]` is applied to a function or static. Returns `true` if valid. |
| fn check_export_name(&self, attr: &Attribute, span: &Span, target: Target) -> bool { |
| match target { |
| Target::Static | Target::Fn | Target::Method(..) => true, |
| _ => { |
| self.tcx |
| .sess |
| .struct_span_err( |
| attr.span, |
| "attribute should be applied to a function or static", |
| ) |
| .span_label(*span, "not a function or static") |
| .emit(); |
| false |
| } |
| } |
| } |
| |
| /// Checks if `#[rustc_args_required_const]` is applied to a function and has a valid argument. |
| fn check_rustc_args_required_const( |
| &self, |
| attr: &Attribute, |
| span: &Span, |
| target: Target, |
| item: Option<ItemLike<'_>>, |
| ) -> bool { |
| if let Target::Fn | Target::Method(..) | Target::ForeignFn = target { |
| let mut invalid_args = vec![]; |
| for meta in attr.meta_item_list().expect("no meta item list") { |
| if let Some(LitKind::Int(val, _)) = meta.literal().map(|lit| &lit.kind) { |
| if let Some(ItemLike::Item(Item { |
| kind: ItemKind::Fn(FnSig { decl, .. }, ..), |
| .. |
| })) |
| | Some(ItemLike::ForeignItem(ForeignItem { |
| kind: ForeignItemKind::Fn(decl, ..), |
| .. |
| })) = item |
| { |
| let arg_count = decl.inputs.len() as u128; |
| if *val >= arg_count { |
| let span = meta.span(); |
| self.tcx |
| .sess |
| .struct_span_err(span, "index exceeds number of arguments") |
| .span_label( |
| span, |
| format!( |
| "there {} only {} argument{}", |
| if arg_count != 1 { "are" } else { "is" }, |
| arg_count, |
| pluralize!(arg_count) |
| ), |
| ) |
| .emit(); |
| return false; |
| } |
| } else { |
| bug!("should be a function item"); |
| } |
| } else { |
| invalid_args.push(meta.span()); |
| } |
| } |
| if !invalid_args.is_empty() { |
| self.tcx |
| .sess |
| .struct_span_err(invalid_args, "arguments should be non-negative integers") |
| .emit(); |
| false |
| } else { |
| true |
| } |
| } else { |
| self.tcx |
| .sess |
| .struct_span_err(attr.span, "attribute should be applied to a function") |
| .span_label(*span, "not a function") |
| .emit(); |
| false |
| } |
| } |
| |
| /// Checks if `#[link_section]` is applied to a function or static. |
| fn check_link_section(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { |
| match target { |
| Target::Static | Target::Fn | Target::Method(..) => {} |
| _ => { |
| // FIXME: #[link_section] was previously allowed on non-functions/statics and some |
| // crates used this, so only emit a warning. |
| self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
| lint.build("attribute should be applied to a function or static") |
| .warn( |
| "this was previously accepted by the compiler but is \ |
| being phased out; it will become a hard error in \ |
| a future release!", |
| ) |
| .span_label(*span, "not a function or static") |
| .emit(); |
| }); |
| } |
| } |
| } |
| |
| /// Checks if `#[no_mangle]` is applied to a function or static. |
| fn check_no_mangle(&self, hir_id: HirId, attr: &Attribute, span: &Span, target: Target) { |
| match target { |
| Target::Static | Target::Fn | Target::Method(..) => {} |
| _ => { |
| // FIXME: #[no_mangle] was previously allowed on non-functions/statics and some |
| // crates used this, so only emit a warning. |
| self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| { |
| lint.build("attribute should be applied to a function or static") |
| .warn( |
| "this was previously accepted by the compiler but is \ |
| being phased out; it will become a hard error in \ |
| a future release!", |
| ) |
| .span_label(*span, "not a function or static") |
| .emit(); |
| }); |
| } |
| } |
| } |
| |
| /// Checks if the `#[repr]` attributes on `item` are valid. |
| fn check_repr( |
| &self, |
| attrs: &'hir [Attribute], |
| span: &Span, |
| target: Target, |
| item: Option<ItemLike<'_>>, |
| hir_id: HirId, |
| ) { |
| // Extract the names of all repr hints, e.g., [foo, bar, align] for: |
| // ``` |
| // #[repr(foo)] |
| // #[repr(bar, align(8))] |
| // ``` |
| let hints: Vec<_> = attrs |
| .iter() |
| .filter(|attr| self.tcx.sess.check_name(attr, sym::repr)) |
| .filter_map(|attr| attr.meta_item_list()) |
| .flatten() |
| .collect(); |
| |
| let mut int_reprs = 0; |
| let mut is_c = false; |
| let mut is_simd = false; |
| let mut is_transparent = false; |
| |
| for hint in &hints { |
| let (article, allowed_targets) = match hint.name_or_empty() { |
| _ if !matches!(target, Target::Struct | Target::Enum | Target::Union) => { |
| ("a", "struct, enum, or union") |
| } |
| name @ sym::C | name @ sym::align => { |
| is_c |= name == sym::C; |
| match target { |
| Target::Struct | Target::Union | Target::Enum => continue, |
| _ => ("a", "struct, enum, or union"), |
| } |
| } |
| sym::packed => { |
| if target != Target::Struct && target != Target::Union { |
| ("a", "struct or union") |
| } else { |
| continue; |
| } |
| } |
| sym::simd => { |
| is_simd = true; |
| if target != Target::Struct { |
| ("a", "struct") |
| } else { |
| continue; |
| } |
| } |
| sym::transparent => { |
| is_transparent = true; |
| match target { |
| Target::Struct | Target::Union | Target::Enum => continue, |
| _ => ("a", "struct, enum, or union"), |
| } |
| } |
| sym::no_niche => { |
| if !self.tcx.features().enabled(sym::no_niche) { |
| feature_err( |
| &self.tcx.sess.parse_sess, |
| sym::no_niche, |
| hint.span(), |
| "the attribute `repr(no_niche)` is currently unstable", |
| ) |
| .emit(); |
| } |
| match target { |
| Target::Struct | Target::Enum => continue, |
| _ => ("a", "struct or enum"), |
| } |
| } |
| sym::i8 |
| | sym::u8 |
| | sym::i16 |
| | sym::u16 |
| | sym::i32 |
| | sym::u32 |
| | sym::i64 |
| | sym::u64 |
| | sym::i128 |
| | sym::u128 |
| | sym::isize |
| | sym::usize => { |
| int_reprs += 1; |
| if target != Target::Enum { |
| ("an", "enum") |
| } else { |
| continue; |
| } |
| } |
| _ => continue, |
| }; |
| |
| struct_span_err!( |
| self.tcx.sess, |
| hint.span(), |
| E0517, |
| "{}", |
| &format!("attribute should be applied to {} {}", article, allowed_targets) |
| ) |
| .span_label(*span, &format!("not {} {}", article, allowed_targets)) |
| .emit(); |
| } |
| |
| // Just point at all repr hints if there are any incompatibilities. |
| // This is not ideal, but tracking precisely which ones are at fault is a huge hassle. |
| let hint_spans = hints.iter().map(|hint| hint.span()); |
| |
| // Error on repr(transparent, <anything else apart from no_niche>). |
| let non_no_niche = |hint: &&NestedMetaItem| hint.name_or_empty() != sym::no_niche; |
| let non_no_niche_count = hints.iter().filter(non_no_niche).count(); |
| if is_transparent && non_no_niche_count > 1 { |
| let hint_spans: Vec<_> = hint_spans.clone().collect(); |
| struct_span_err!( |
| self.tcx.sess, |
| hint_spans, |
| E0692, |
| "transparent {} cannot have other repr hints", |
| target |
| ) |
| .emit(); |
| } |
| // Warn on repr(u8, u16), repr(C, simd), and c-like-enum-repr(C, u8) |
| if (int_reprs > 1) |
| || (is_simd && is_c) |
| || (int_reprs == 1 |
| && is_c |
| && item.map_or(false, |item| { |
| if let ItemLike::Item(item) = item { |
| return is_c_like_enum(item); |
| } |
| return false; |
| })) |
| { |
| self.tcx.struct_span_lint_hir( |
| CONFLICTING_REPR_HINTS, |
| hir_id, |
| hint_spans.collect::<Vec<Span>>(), |
| |lint| { |
| lint.build("conflicting representation hints") |
| .code(rustc_errors::error_code!(E0566)) |
| .emit(); |
| }, |
| ); |
| } |
| } |
| |
| fn check_used(&self, attrs: &'hir [Attribute], target: Target) { |
| for attr in attrs { |
| if self.tcx.sess.check_name(attr, sym::used) && target != Target::Static { |
| self.tcx |
| .sess |
| .span_err(attr.span, "attribute must be applied to a `static` variable"); |
| } |
| } |
| } |
| } |
| |
| impl Visitor<'tcx> for CheckAttrVisitor<'tcx> { |
| type Map = Map<'tcx>; |
| |
| fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { |
| NestedVisitorMap::OnlyBodies(self.tcx.hir()) |
| } |
| |
| fn visit_item(&mut self, item: &'tcx Item<'tcx>) { |
| let target = Target::from_item(item); |
| self.check_attributes( |
| item.hir_id, |
| item.attrs, |
| &item.span, |
| target, |
| Some(ItemLike::Item(item)), |
| ); |
| intravisit::walk_item(self, item) |
| } |
| |
| fn visit_trait_item(&mut self, trait_item: &'tcx TraitItem<'tcx>) { |
| let target = Target::from_trait_item(trait_item); |
| self.check_attributes(trait_item.hir_id, &trait_item.attrs, &trait_item.span, target, None); |
| intravisit::walk_trait_item(self, trait_item) |
| } |
| |
| fn visit_foreign_item(&mut self, f_item: &'tcx ForeignItem<'tcx>) { |
| let target = Target::from_foreign_item(f_item); |
| self.check_attributes( |
| f_item.hir_id, |
| &f_item.attrs, |
| &f_item.span, |
| target, |
| Some(ItemLike::ForeignItem(f_item)), |
| ); |
| intravisit::walk_foreign_item(self, f_item) |
| } |
| |
| fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) { |
| let target = target_from_impl_item(self.tcx, impl_item); |
| self.check_attributes(impl_item.hir_id, &impl_item.attrs, &impl_item.span, target, None); |
| intravisit::walk_impl_item(self, impl_item) |
| } |
| |
| fn visit_stmt(&mut self, stmt: &'tcx hir::Stmt<'tcx>) { |
| // When checking statements ignore expressions, they will be checked later. |
| if let hir::StmtKind::Local(ref l) = stmt.kind { |
| self.check_attributes(l.hir_id, &l.attrs, &stmt.span, Target::Statement, None); |
| } |
| intravisit::walk_stmt(self, stmt) |
| } |
| |
| fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) { |
| let target = match expr.kind { |
| hir::ExprKind::Closure(..) => Target::Closure, |
| _ => Target::Expression, |
| }; |
| |
| self.check_attributes(expr.hir_id, &expr.attrs, &expr.span, target, None); |
| intravisit::walk_expr(self, expr) |
| } |
| |
| fn visit_variant( |
| &mut self, |
| variant: &'tcx hir::Variant<'tcx>, |
| generics: &'tcx hir::Generics<'tcx>, |
| item_id: HirId, |
| ) { |
| self.check_attributes(variant.id, variant.attrs, &variant.span, Target::Variant, None); |
| intravisit::walk_variant(self, variant, generics, item_id) |
| } |
| } |
| |
| fn is_c_like_enum(item: &Item<'_>) -> bool { |
| if let ItemKind::Enum(ref def, _) = item.kind { |
| for variant in def.variants { |
| match variant.data { |
| hir::VariantData::Unit(..) => { /* continue */ } |
| _ => return false, |
| } |
| } |
| true |
| } else { |
| false |
| } |
| } |
| |
| fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) { |
| const ATTRS_TO_CHECK: &[Symbol] = &[ |
| sym::macro_export, |
| sym::repr, |
| sym::path, |
| sym::automatically_derived, |
| sym::start, |
| sym::main, |
| ]; |
| |
| for attr in attrs { |
| for attr_to_check in ATTRS_TO_CHECK { |
| if tcx.sess.check_name(attr, *attr_to_check) { |
| tcx.sess |
| .struct_span_err( |
| attr.span, |
| &format!( |
| "`{}` attribute cannot be used at crate level", |
| attr_to_check.to_ident_string() |
| ), |
| ) |
| .emit(); |
| } |
| } |
| } |
| } |
| |
| fn check_mod_attrs(tcx: TyCtxt<'_>, module_def_id: LocalDefId) { |
| tcx.hir() |
| .visit_item_likes_in_module(module_def_id, &mut CheckAttrVisitor { tcx }.as_deep_visitor()); |
| if module_def_id.is_top_level_module() { |
| CheckAttrVisitor { tcx }.check_attributes( |
| CRATE_HIR_ID, |
| tcx.hir().krate_attrs(), |
| &DUMMY_SP, |
| Target::Mod, |
| None, |
| ); |
| check_invalid_crate_level_attr(tcx, tcx.hir().krate_attrs()); |
| } |
| } |
| |
| pub(crate) fn provide(providers: &mut Providers) { |
| *providers = Providers { check_mod_attrs, ..*providers }; |
| } |
