| // Copyright 2013 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // This implements the dead-code warning pass. It follows middle::reachable |
| // closely. The idea is that all reachable symbols are live, codes called |
| // from live codes are live, and everything else is dead. |
| |
| use hir::map as hir_map; |
| use hir::{self, PatKind}; |
| use hir::intravisit::{self, Visitor, NestedVisitorMap}; |
| use hir::itemlikevisit::ItemLikeVisitor; |
| |
| use hir::def::Def; |
| use hir::def_id::{DefId, LOCAL_CRATE}; |
| use lint; |
| use middle::privacy; |
| use ty::{self, TyCtxt}; |
| use util::nodemap::FxHashSet; |
| |
| use syntax::{ast, source_map}; |
| use syntax::attr; |
| use syntax_pos; |
| |
| // Any local node that may call something in its body block should be |
| // explored. For example, if it's a live NodeItem that is a |
| // function, then we should explore its block to check for codes that |
| // may need to be marked as live. |
| fn should_explore<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| node_id: ast::NodeId) -> bool { |
| match tcx.hir.find(node_id) { |
| Some(hir_map::NodeItem(..)) | |
| Some(hir_map::NodeImplItem(..)) | |
| Some(hir_map::NodeForeignItem(..)) | |
| Some(hir_map::NodeTraitItem(..)) => |
| true, |
| _ => |
| false |
| } |
| } |
| |
| struct MarkSymbolVisitor<'a, 'tcx: 'a> { |
| worklist: Vec<ast::NodeId>, |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| tables: &'a ty::TypeckTables<'tcx>, |
| live_symbols: Box<FxHashSet<ast::NodeId>>, |
| repr_has_repr_c: bool, |
| in_pat: bool, |
| inherited_pub_visibility: bool, |
| ignore_variant_stack: Vec<DefId>, |
| } |
| |
| impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> { |
| fn check_def_id(&mut self, def_id: DefId) { |
| if let Some(node_id) = self.tcx.hir.as_local_node_id(def_id) { |
| if should_explore(self.tcx, node_id) { |
| self.worklist.push(node_id); |
| } |
| self.live_symbols.insert(node_id); |
| } |
| } |
| |
| fn insert_def_id(&mut self, def_id: DefId) { |
| if let Some(node_id) = self.tcx.hir.as_local_node_id(def_id) { |
| debug_assert!(!should_explore(self.tcx, node_id)); |
| self.live_symbols.insert(node_id); |
| } |
| } |
| |
| fn handle_definition(&mut self, def: Def) { |
| match def { |
| Def::Const(_) | Def::AssociatedConst(..) | Def::TyAlias(_) => { |
| self.check_def_id(def.def_id()); |
| } |
| _ if self.in_pat => (), |
| Def::PrimTy(..) | Def::SelfTy(..) | |
| Def::Local(..) | Def::Upvar(..) => {} |
| Def::Variant(variant_id) | Def::VariantCtor(variant_id, ..) => { |
| if let Some(enum_id) = self.tcx.parent_def_id(variant_id) { |
| self.check_def_id(enum_id); |
| } |
| if !self.ignore_variant_stack.contains(&variant_id) { |
| self.check_def_id(variant_id); |
| } |
| } |
| _ => { |
| self.check_def_id(def.def_id()); |
| } |
| } |
| } |
| |
| fn lookup_and_handle_method(&mut self, id: hir::HirId) { |
| if let Some(def) = self.tables.type_dependent_defs().get(id) { |
| self.check_def_id(def.def_id()); |
| } else { |
| bug!("no type-dependent def for method"); |
| } |
| } |
| |
| fn handle_field_access(&mut self, lhs: &hir::Expr, node_id: ast::NodeId) { |
| match self.tables.expr_ty_adjusted(lhs).sty { |
| ty::TyAdt(def, _) => { |
| let index = self.tcx.field_index(node_id, self.tables); |
| self.insert_def_id(def.non_enum_variant().fields[index].did); |
| } |
| ty::TyTuple(..) => {} |
| _ => span_bug!(lhs.span, "named field access on non-ADT"), |
| } |
| } |
| |
| fn handle_field_pattern_match(&mut self, lhs: &hir::Pat, def: Def, |
| pats: &[source_map::Spanned<hir::FieldPat>]) { |
| let variant = match self.tables.node_id_to_type(lhs.hir_id).sty { |
| ty::TyAdt(adt, _) => adt.variant_of_def(def), |
| _ => span_bug!(lhs.span, "non-ADT in struct pattern") |
| }; |
| for pat in pats { |
| if let PatKind::Wild = pat.node.pat.node { |
| continue; |
| } |
| let index = self.tcx.field_index(pat.node.id, self.tables); |
| self.insert_def_id(variant.fields[index].did); |
| } |
| } |
| |
| fn mark_live_symbols(&mut self) { |
| let mut scanned = FxHashSet(); |
| while !self.worklist.is_empty() { |
| let id = self.worklist.pop().unwrap(); |
| if scanned.contains(&id) { |
| continue |
| } |
| scanned.insert(id); |
| |
| if let Some(ref node) = self.tcx.hir.find(id) { |
| self.live_symbols.insert(id); |
| self.visit_node(node); |
| } |
| } |
| } |
| |
| fn visit_node(&mut self, node: &hir_map::Node<'tcx>) { |
| let had_repr_c = self.repr_has_repr_c; |
| self.repr_has_repr_c = false; |
| let had_inherited_pub_visibility = self.inherited_pub_visibility; |
| self.inherited_pub_visibility = false; |
| match *node { |
| hir_map::NodeItem(item) => { |
| match item.node { |
| hir::ItemKind::Struct(..) | hir::ItemKind::Union(..) => { |
| let def_id = self.tcx.hir.local_def_id(item.id); |
| let def = self.tcx.adt_def(def_id); |
| self.repr_has_repr_c = def.repr.c(); |
| |
| intravisit::walk_item(self, &item); |
| } |
| hir::ItemKind::Enum(..) => { |
| self.inherited_pub_visibility = item.vis.node.is_pub(); |
| intravisit::walk_item(self, &item); |
| } |
| hir::ItemKind::Fn(..) |
| | hir::ItemKind::Ty(..) |
| | hir::ItemKind::Static(..) |
| | hir::ItemKind::Const(..) => { |
| intravisit::walk_item(self, &item); |
| } |
| _ => () |
| } |
| } |
| hir_map::NodeTraitItem(trait_item) => { |
| intravisit::walk_trait_item(self, trait_item); |
| } |
| hir_map::NodeImplItem(impl_item) => { |
| intravisit::walk_impl_item(self, impl_item); |
| } |
| hir_map::NodeForeignItem(foreign_item) => { |
| intravisit::walk_foreign_item(self, &foreign_item); |
| } |
| _ => () |
| } |
| self.repr_has_repr_c = had_repr_c; |
| self.inherited_pub_visibility = had_inherited_pub_visibility; |
| } |
| |
| fn mark_as_used_if_union(&mut self, adt: &ty::AdtDef, fields: &hir::HirVec<hir::Field>) { |
| if adt.is_union() && adt.non_enum_variant().fields.len() > 1 && adt.did.is_local() { |
| for field in fields { |
| let index = self.tcx.field_index(field.id, self.tables); |
| self.insert_def_id(adt.non_enum_variant().fields[index].did); |
| } |
| } |
| } |
| } |
| |
| impl<'a, 'tcx> Visitor<'tcx> for MarkSymbolVisitor<'a, 'tcx> { |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| NestedVisitorMap::None |
| } |
| |
| fn visit_nested_body(&mut self, body: hir::BodyId) { |
| let old_tables = self.tables; |
| self.tables = self.tcx.body_tables(body); |
| let body = self.tcx.hir.body(body); |
| self.visit_body(body); |
| self.tables = old_tables; |
| } |
| |
| fn visit_variant_data(&mut self, def: &'tcx hir::VariantData, _: ast::Name, |
| _: &hir::Generics, _: ast::NodeId, _: syntax_pos::Span) { |
| let has_repr_c = self.repr_has_repr_c; |
| let inherited_pub_visibility = self.inherited_pub_visibility; |
| let live_fields = def.fields().iter().filter(|f| { |
| has_repr_c || inherited_pub_visibility || f.vis.node.is_pub() |
| }); |
| self.live_symbols.extend(live_fields.map(|f| f.id)); |
| |
| intravisit::walk_struct_def(self, def); |
| } |
| |
| fn visit_expr(&mut self, expr: &'tcx hir::Expr) { |
| match expr.node { |
| hir::ExprKind::Path(ref qpath @ hir::QPath::TypeRelative(..)) => { |
| let def = self.tables.qpath_def(qpath, expr.hir_id); |
| self.handle_definition(def); |
| } |
| hir::ExprKind::MethodCall(..) => { |
| self.lookup_and_handle_method(expr.hir_id); |
| } |
| hir::ExprKind::Field(ref lhs, ..) => { |
| self.handle_field_access(&lhs, expr.id); |
| } |
| hir::ExprKind::Struct(_, ref fields, _) => { |
| if let ty::TypeVariants::TyAdt(ref adt, _) = self.tables.expr_ty(expr).sty { |
| self.mark_as_used_if_union(adt, fields); |
| } |
| } |
| _ => () |
| } |
| |
| intravisit::walk_expr(self, expr); |
| } |
| |
| fn visit_arm(&mut self, arm: &'tcx hir::Arm) { |
| if arm.pats.len() == 1 { |
| let variants = arm.pats[0].necessary_variants(); |
| |
| // Inside the body, ignore constructions of variants |
| // necessary for the pattern to match. Those construction sites |
| // can't be reached unless the variant is constructed elsewhere. |
| let len = self.ignore_variant_stack.len(); |
| self.ignore_variant_stack.extend_from_slice(&variants); |
| intravisit::walk_arm(self, arm); |
| self.ignore_variant_stack.truncate(len); |
| } else { |
| intravisit::walk_arm(self, arm); |
| } |
| } |
| |
| fn visit_pat(&mut self, pat: &'tcx hir::Pat) { |
| match pat.node { |
| PatKind::Struct(hir::QPath::Resolved(_, ref path), ref fields, _) => { |
| self.handle_field_pattern_match(pat, path.def, fields); |
| } |
| PatKind::Path(ref qpath @ hir::QPath::TypeRelative(..)) => { |
| let def = self.tables.qpath_def(qpath, pat.hir_id); |
| self.handle_definition(def); |
| } |
| _ => () |
| } |
| |
| self.in_pat = true; |
| intravisit::walk_pat(self, pat); |
| self.in_pat = false; |
| } |
| |
| fn visit_path(&mut self, path: &'tcx hir::Path, _: hir::HirId) { |
| self.handle_definition(path.def); |
| intravisit::walk_path(self, path); |
| } |
| } |
| |
| fn has_allow_dead_code_or_lang_attr(tcx: TyCtxt, |
| id: ast::NodeId, |
| attrs: &[ast::Attribute]) -> bool { |
| if attr::contains_name(attrs, "lang") { |
| return true; |
| } |
| |
| // (To be) stable attribute for #[lang = "panic_impl"] |
| if attr::contains_name(attrs, "panic_implementation") { |
| return true; |
| } |
| |
| // (To be) stable attribute for #[lang = "oom"] |
| if attr::contains_name(attrs, "alloc_error_handler") { |
| return true; |
| } |
| |
| // #[used] also keeps the item alive forcefully, |
| // e.g. for placing it in a specific section. |
| if attr::contains_name(attrs, "used") { |
| return true; |
| } |
| |
| // Don't lint about global allocators |
| if attr::contains_name(attrs, "global_allocator") { |
| return true; |
| } |
| |
| tcx.lint_level_at_node(lint::builtin::DEAD_CODE, id).0 == lint::Allow |
| } |
| |
| // This visitor seeds items that |
| // 1) We want to explicitly consider as live: |
| // * Item annotated with #[allow(dead_code)] |
| // - This is done so that if we want to suppress warnings for a |
| // group of dead functions, we only have to annotate the "root". |
| // For example, if both `f` and `g` are dead and `f` calls `g`, |
| // then annotating `f` with `#[allow(dead_code)]` will suppress |
| // warning for both `f` and `g`. |
| // * Item annotated with #[lang=".."] |
| // - This is because lang items are always callable from elsewhere. |
| // or |
| // 2) We are not sure to be live or not |
| // * Implementation of a trait method |
| struct LifeSeeder<'k, 'tcx: 'k> { |
| worklist: Vec<ast::NodeId>, |
| krate: &'k hir::Crate, |
| tcx: TyCtxt<'k, 'tcx, 'tcx>, |
| } |
| |
| impl<'v, 'k, 'tcx> ItemLikeVisitor<'v> for LifeSeeder<'k, 'tcx> { |
| fn visit_item(&mut self, item: &hir::Item) { |
| let allow_dead_code = has_allow_dead_code_or_lang_attr(self.tcx, |
| item.id, |
| &item.attrs); |
| if allow_dead_code { |
| self.worklist.push(item.id); |
| } |
| match item.node { |
| hir::ItemKind::Enum(ref enum_def, _) if allow_dead_code => { |
| self.worklist.extend(enum_def.variants.iter() |
| .map(|variant| variant.node.data.id())); |
| } |
| hir::ItemKind::Trait(.., ref trait_item_refs) => { |
| for trait_item_ref in trait_item_refs { |
| let trait_item = self.krate.trait_item(trait_item_ref.id); |
| match trait_item.node { |
| hir::TraitItemKind::Const(_, Some(_)) | |
| hir::TraitItemKind::Method(_, hir::TraitMethod::Provided(_)) => { |
| if has_allow_dead_code_or_lang_attr(self.tcx, |
| trait_item.id, |
| &trait_item.attrs) { |
| self.worklist.push(trait_item.id); |
| } |
| } |
| _ => {} |
| } |
| } |
| } |
| hir::ItemKind::Impl(.., ref opt_trait, _, ref impl_item_refs) => { |
| for impl_item_ref in impl_item_refs { |
| let impl_item = self.krate.impl_item(impl_item_ref.id); |
| if opt_trait.is_some() || |
| has_allow_dead_code_or_lang_attr(self.tcx, |
| impl_item.id, |
| &impl_item.attrs) { |
| self.worklist.push(impl_item_ref.id.node_id); |
| } |
| } |
| } |
| _ => () |
| } |
| } |
| |
| fn visit_trait_item(&mut self, _item: &hir::TraitItem) { |
| // ignore: we are handling this in `visit_item` above |
| } |
| |
| fn visit_impl_item(&mut self, _item: &hir::ImplItem) { |
| // ignore: we are handling this in `visit_item` above |
| } |
| } |
| |
| fn create_and_seed_worklist<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| access_levels: &privacy::AccessLevels, |
| krate: &hir::Crate) |
| -> Vec<ast::NodeId> |
| { |
| let worklist = access_levels.map.iter().map(|(&id, _)| id).chain( |
| // Seed entry point |
| tcx.sess.entry_fn.borrow().map(|(id, _, _)| id) |
| ).collect::<Vec<_>>(); |
| |
| // Seed implemented trait items |
| let mut life_seeder = LifeSeeder { |
| worklist, |
| krate, |
| tcx, |
| }; |
| krate.visit_all_item_likes(&mut life_seeder); |
| |
| return life_seeder.worklist; |
| } |
| |
| fn find_live<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| access_levels: &privacy::AccessLevels, |
| krate: &hir::Crate) |
| -> Box<FxHashSet<ast::NodeId>> { |
| let worklist = create_and_seed_worklist(tcx, access_levels, krate); |
| let mut symbol_visitor = MarkSymbolVisitor { |
| worklist, |
| tcx, |
| tables: &ty::TypeckTables::empty(None), |
| live_symbols: box FxHashSet(), |
| repr_has_repr_c: false, |
| in_pat: false, |
| inherited_pub_visibility: false, |
| ignore_variant_stack: vec![], |
| }; |
| symbol_visitor.mark_live_symbols(); |
| symbol_visitor.live_symbols |
| } |
| |
| fn get_struct_ctor_id(item: &hir::Item) -> Option<ast::NodeId> { |
| match item.node { |
| hir::ItemKind::Struct(ref struct_def, _) if !struct_def.is_struct() => { |
| Some(struct_def.id()) |
| } |
| _ => None |
| } |
| } |
| |
| struct DeadVisitor<'a, 'tcx: 'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| live_symbols: Box<FxHashSet<ast::NodeId>>, |
| } |
| |
| impl<'a, 'tcx> DeadVisitor<'a, 'tcx> { |
| fn should_warn_about_item(&mut self, item: &hir::Item) -> bool { |
| let should_warn = match item.node { |
| hir::ItemKind::Static(..) |
| | hir::ItemKind::Const(..) |
| | hir::ItemKind::Fn(..) |
| | hir::ItemKind::Ty(..) |
| | hir::ItemKind::Enum(..) |
| | hir::ItemKind::Struct(..) |
| | hir::ItemKind::Union(..) => true, |
| _ => false |
| }; |
| let ctor_id = get_struct_ctor_id(item); |
| should_warn && !self.symbol_is_live(item.id, ctor_id) |
| } |
| |
| fn should_warn_about_field(&mut self, field: &hir::StructField) -> bool { |
| let field_type = self.tcx.type_of(self.tcx.hir.local_def_id(field.id)); |
| !field.is_positional() |
| && !self.symbol_is_live(field.id, None) |
| && !field_type.is_phantom_data() |
| && !has_allow_dead_code_or_lang_attr(self.tcx, field.id, &field.attrs) |
| } |
| |
| fn should_warn_about_variant(&mut self, variant: &hir::VariantKind) -> bool { |
| !self.symbol_is_live(variant.data.id(), None) |
| && !has_allow_dead_code_or_lang_attr(self.tcx, |
| variant.data.id(), |
| &variant.attrs) |
| } |
| |
| fn should_warn_about_foreign_item(&mut self, fi: &hir::ForeignItem) -> bool { |
| !self.symbol_is_live(fi.id, None) |
| && !has_allow_dead_code_or_lang_attr(self.tcx, fi.id, &fi.attrs) |
| } |
| |
| // id := node id of an item's definition. |
| // ctor_id := `Some` if the item is a struct_ctor (tuple struct), |
| // `None` otherwise. |
| // If the item is a struct_ctor, then either its `id` or |
| // `ctor_id` (unwrapped) is in the live_symbols set. More specifically, |
| // DefMap maps the ExprKind::Path of a struct_ctor to the node referred by |
| // `ctor_id`. On the other hand, in a statement like |
| // `type <ident> <generics> = <ty>;` where <ty> refers to a struct_ctor, |
| // DefMap maps <ty> to `id` instead. |
| fn symbol_is_live(&mut self, |
| id: ast::NodeId, |
| ctor_id: Option<ast::NodeId>) |
| -> bool { |
| if self.live_symbols.contains(&id) |
| || ctor_id.map_or(false, |
| |ctor| self.live_symbols.contains(&ctor)) { |
| return true; |
| } |
| // If it's a type whose items are live, then it's live, too. |
| // This is done to handle the case where, for example, the static |
| // method of a private type is used, but the type itself is never |
| // called directly. |
| let def_id = self.tcx.hir.local_def_id(id); |
| let inherent_impls = self.tcx.inherent_impls(def_id); |
| for &impl_did in inherent_impls.iter() { |
| for &item_did in &self.tcx.associated_item_def_ids(impl_did)[..] { |
| if let Some(item_node_id) = self.tcx.hir.as_local_node_id(item_did) { |
| if self.live_symbols.contains(&item_node_id) { |
| return true; |
| } |
| } |
| } |
| } |
| false |
| } |
| |
| fn warn_dead_code(&mut self, |
| id: ast::NodeId, |
| span: syntax_pos::Span, |
| name: ast::Name, |
| node_type: &str, |
| participle: &str) { |
| if !name.as_str().starts_with("_") { |
| self.tcx |
| .lint_node(lint::builtin::DEAD_CODE, |
| id, |
| span, |
| &format!("{} is never {}: `{}`", |
| node_type, participle, name)); |
| } |
| } |
| } |
| |
| impl<'a, 'tcx> Visitor<'tcx> for DeadVisitor<'a, 'tcx> { |
| /// Walk nested items in place so that we don't report dead-code |
| /// on inner functions when the outer function is already getting |
| /// an error. We could do this also by checking the parents, but |
| /// this is how the code is setup and it seems harmless enough. |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| NestedVisitorMap::All(&self.tcx.hir) |
| } |
| |
| fn visit_item(&mut self, item: &'tcx hir::Item) { |
| if self.should_warn_about_item(item) { |
| // For items that have a definition with a signature followed by a |
| // block, point only at the signature. |
| let span = match item.node { |
| hir::ItemKind::Fn(..) | |
| hir::ItemKind::Mod(..) | |
| hir::ItemKind::Enum(..) | |
| hir::ItemKind::Struct(..) | |
| hir::ItemKind::Union(..) | |
| hir::ItemKind::Trait(..) | |
| hir::ItemKind::Impl(..) => self.tcx.sess.source_map().def_span(item.span), |
| _ => item.span, |
| }; |
| let participle = match item.node { |
| hir::ItemKind::Struct(..) => "constructed", // Issue #52325 |
| _ => "used" |
| }; |
| self.warn_dead_code( |
| item.id, |
| span, |
| item.name, |
| item.node.descriptive_variant(), |
| participle, |
| ); |
| } else { |
| // Only continue if we didn't warn |
| intravisit::walk_item(self, item); |
| } |
| } |
| |
| fn visit_variant(&mut self, |
| variant: &'tcx hir::Variant, |
| g: &'tcx hir::Generics, |
| id: ast::NodeId) { |
| if self.should_warn_about_variant(&variant.node) { |
| self.warn_dead_code(variant.node.data.id(), variant.span, variant.node.name, |
| "variant", "constructed"); |
| } else { |
| intravisit::walk_variant(self, variant, g, id); |
| } |
| } |
| |
| fn visit_foreign_item(&mut self, fi: &'tcx hir::ForeignItem) { |
| if self.should_warn_about_foreign_item(fi) { |
| self.warn_dead_code(fi.id, fi.span, fi.name, |
| fi.node.descriptive_variant(), "used"); |
| } |
| intravisit::walk_foreign_item(self, fi); |
| } |
| |
| fn visit_struct_field(&mut self, field: &'tcx hir::StructField) { |
| if self.should_warn_about_field(&field) { |
| self.warn_dead_code(field.id, field.span, field.ident.name, "field", "used"); |
| } |
| intravisit::walk_struct_field(self, field); |
| } |
| |
| fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) { |
| match impl_item.node { |
| hir::ImplItemKind::Const(_, body_id) => { |
| if !self.symbol_is_live(impl_item.id, None) { |
| self.warn_dead_code(impl_item.id, |
| impl_item.span, |
| impl_item.ident.name, |
| "associated const", |
| "used"); |
| } |
| self.visit_nested_body(body_id) |
| } |
| hir::ImplItemKind::Method(_, body_id) => { |
| if !self.symbol_is_live(impl_item.id, None) { |
| let span = self.tcx.sess.source_map().def_span(impl_item.span); |
| self.warn_dead_code(impl_item.id, span, impl_item.ident.name, "method", "used"); |
| } |
| self.visit_nested_body(body_id) |
| } |
| hir::ImplItemKind::Existential(..) | |
| hir::ImplItemKind::Type(..) => {} |
| } |
| } |
| |
| // Overwrite so that we don't warn the trait item itself. |
| fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) { |
| match trait_item.node { |
| hir::TraitItemKind::Const(_, Some(body_id)) | |
| hir::TraitItemKind::Method(_, hir::TraitMethod::Provided(body_id)) => { |
| self.visit_nested_body(body_id) |
| } |
| hir::TraitItemKind::Const(_, None) | |
| hir::TraitItemKind::Method(_, hir::TraitMethod::Required(_)) | |
| hir::TraitItemKind::Type(..) => {} |
| } |
| } |
| } |
| |
| pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) { |
| let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE); |
| let krate = tcx.hir.krate(); |
| let live_symbols = find_live(tcx, access_levels, krate); |
| let mut visitor = DeadVisitor { |
| tcx, |
| live_symbols, |
| }; |
| intravisit::walk_crate(&mut visitor, krate); |
| } |