1 use crate::{ImportKind, NameBinding, NameBindingKind, Resolver, ResolverTree};
4 use rustc_ast::visit::Visitor;
6 use rustc_ast::EnumDef;
7 use rustc_data_structures::intern::Interned;
8 use rustc_hir::def_id::LocalDefId;
9 use rustc_hir::def_id::CRATE_DEF_ID;
10 use rustc_middle::middle::privacy::{EffectiveVisibilities, EffectiveVisibility, Level};
11 use rustc_middle::ty::Visibility;
13 type ImportId<'a> = Interned<'a, NameBinding<'a>>;
15 #[derive(Clone, Copy)]
22 fn level(self) -> Level {
24 ParentId::Def(_) => Level::Direct,
25 ParentId::Import(_) => Level::Reexported,
30 pub struct EffectiveVisibilitiesVisitor<'r, 'a> {
31 r: &'r mut Resolver<'a>,
32 /// While walking import chains we need to track effective visibilities per-binding, and def id
33 /// keys in `Resolver::effective_visibilities` are not enough for that, because multiple
34 /// bindings can correspond to a single def id in imports. So we keep a separate table.
35 import_effective_visibilities: EffectiveVisibilities<ImportId<'a>>,
39 impl<'r, 'a> EffectiveVisibilitiesVisitor<'r, 'a> {
40 /// Fills the `Resolver::effective_visibilities` table with public & exported items
41 /// For now, this doesn't resolve macros (FIXME) and cannot resolve Impl, as we
42 /// need access to a TyCtxt for that.
43 pub fn compute_effective_visibilities<'c>(r: &'r mut Resolver<'a>, krate: &'c Crate) {
44 let mut visitor = EffectiveVisibilitiesVisitor {
46 import_effective_visibilities: Default::default(),
50 visitor.update(CRATE_DEF_ID, CRATE_DEF_ID);
51 visitor.set_bindings_effective_visibilities(CRATE_DEF_ID);
53 while visitor.changed {
54 visitor.changed = false;
55 visit::walk_crate(&mut visitor, krate);
58 // Update visibilities for import def ids. These are not used during the
59 // `EffectiveVisibilitiesVisitor` pass, because we have more detailed binding-based
60 // information, but are used by later passes. Effective visibility of an import def id
61 // is the maximum value among visibilities of bindings corresponding to that def id.
62 for (binding, eff_vis) in visitor.import_effective_visibilities.iter() {
63 let NameBindingKind::Import { import, .. } = binding.kind else { unreachable!() };
64 if let Some(node_id) = import.id() {
65 let mut update = |node_id| {
66 r.effective_visibilities.update_eff_vis(
67 r.local_def_id(node_id),
69 ResolverTree(&r.definitions, &r.crate_loader),
73 if let ImportKind::Single { additional_ids: (id1, id2), .. } = import.kind {
74 // In theory all the single import IDs have individual visibilities and
75 // effective visibilities, but in practice these IDs go straigth to HIR
76 // where all their few uses assume that their (effective) visibility
77 // applies to the whole syntactic `use` item. So they all get the same
78 // value which is the maximum of all bindings. Maybe HIR for imports
79 // shouldn't use three IDs at all.
80 if id1 != ast::DUMMY_NODE_ID {
83 if id2 != ast::DUMMY_NODE_ID {
90 info!("resolve::effective_visibilities: {:#?}", r.effective_visibilities);
93 fn nearest_normal_mod(&mut self, def_id: LocalDefId) -> LocalDefId {
94 self.r.get_nearest_non_block_module(def_id.to_def_id()).nearest_parent_mod().expect_local()
97 /// Update effective visibilities of bindings in the given module,
98 /// including their whole reexport chains.
99 fn set_bindings_effective_visibilities(&mut self, module_id: LocalDefId) {
100 assert!(self.r.module_map.contains_key(&&module_id.to_def_id()));
101 let module = self.r.get_module(module_id.to_def_id()).unwrap();
102 let resolutions = self.r.resolutions(module);
104 for (_, name_resolution) in resolutions.borrow().iter() {
105 if let Some(mut binding) = name_resolution.borrow().binding() && !binding.is_ambiguity() {
106 // Set the given effective visibility level to `Level::Direct` and
107 // sets the rest of the `use` chain to `Level::Reexported` until
108 // we hit the actual exported item.
109 let mut parent_id = ParentId::Def(module_id);
110 while let NameBindingKind::Import { binding: nested_binding, .. } = binding.kind {
111 let binding_id = ImportId::new_unchecked(binding);
112 self.update_import(binding_id, parent_id);
114 parent_id = ParentId::Import(binding_id);
115 binding = nested_binding;
118 if let Some(def_id) = binding.res().opt_def_id().and_then(|id| id.as_local()) {
119 self.update_def(def_id, binding.vis.expect_local(), parent_id);
125 fn effective_vis(&self, parent_id: ParentId<'a>) -> Option<EffectiveVisibility> {
127 ParentId::Def(def_id) => self.r.effective_visibilities.effective_vis(def_id),
128 ParentId::Import(binding) => self.import_effective_visibilities.effective_vis(binding),
133 /// The update is guaranteed to not change the table and we can skip it.
136 parent_id: ParentId<'a>,
137 nominal_vis: Visibility,
138 default_vis: Visibility,
140 nominal_vis == default_vis
142 ParentId::Def(def_id) => self.r.visibilities[&def_id],
143 ParentId::Import(binding) => binding.vis.expect_local(),
147 fn update_import(&mut self, binding: ImportId<'a>, parent_id: ParentId<'a>) {
148 let NameBindingKind::Import { import, .. } = binding.kind else { unreachable!() };
149 let nominal_vis = binding.vis.expect_local();
150 let default_vis = Visibility::Restricted(
153 .map(|id| self.nearest_normal_mod(self.r.local_def_id(id)))
154 .unwrap_or(CRATE_DEF_ID),
156 if self.is_noop_update(parent_id, nominal_vis, default_vis) {
159 self.changed |= self.import_effective_visibilities.update(
163 self.effective_vis(parent_id),
165 ResolverTree(&self.r.definitions, &self.r.crate_loader),
169 fn update_def(&mut self, def_id: LocalDefId, nominal_vis: Visibility, parent_id: ParentId<'a>) {
170 let default_vis = Visibility::Restricted(self.nearest_normal_mod(def_id));
171 if self.is_noop_update(parent_id, nominal_vis, default_vis) {
174 self.changed |= self.r.effective_visibilities.update(
177 if def_id == CRATE_DEF_ID { Visibility::Public } else { default_vis },
178 self.effective_vis(parent_id),
180 ResolverTree(&self.r.definitions, &self.r.crate_loader),
184 fn update(&mut self, def_id: LocalDefId, parent_id: LocalDefId) {
185 self.update_def(def_id, self.r.visibilities[&def_id], ParentId::Def(parent_id));
189 impl<'r, 'ast> Visitor<'ast> for EffectiveVisibilitiesVisitor<'ast, 'r> {
190 fn visit_item(&mut self, item: &'ast ast::Item) {
191 let def_id = self.r.local_def_id(item.id);
192 // Update effective visibilities of nested items.
193 // If it's a mod, also make the visitor walk all of its items
195 // Resolved in rustc_privacy when types are available
196 ast::ItemKind::Impl(..) => return,
198 // Should be unreachable at this stage
199 ast::ItemKind::MacCall(..) => panic!(
200 "ast::ItemKind::MacCall encountered, this should not anymore appear at this stage"
203 ast::ItemKind::Mod(..) => {
204 self.set_bindings_effective_visibilities(def_id);
205 visit::walk_item(self, item);
208 ast::ItemKind::Enum(EnumDef { ref variants }, _) => {
209 self.set_bindings_effective_visibilities(def_id);
210 for variant in variants {
211 let variant_def_id = self.r.local_def_id(variant.id);
212 for field in variant.data.fields() {
213 self.update(self.r.local_def_id(field.id), variant_def_id);
218 ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => {
219 for field in def.fields() {
220 self.update(self.r.local_def_id(field.id), def_id);
224 ast::ItemKind::Trait(..) => {
225 self.set_bindings_effective_visibilities(def_id);
228 ast::ItemKind::ExternCrate(..)
229 | ast::ItemKind::Use(..)
230 | ast::ItemKind::Static(..)
231 | ast::ItemKind::Const(..)
232 | ast::ItemKind::GlobalAsm(..)
233 | ast::ItemKind::TyAlias(..)
234 | ast::ItemKind::TraitAlias(..)
235 | ast::ItemKind::MacroDef(..)
236 | ast::ItemKind::ForeignMod(..)
237 | ast::ItemKind::Fn(..) => return,