1 use crate::{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};
11 use rustc_middle::middle::privacy::{IntoDefIdTree, Level};
12 use rustc_middle::ty::{DefIdTree, Visibility};
15 type ImportId<'a> = Interned<'a, NameBinding<'a>>;
17 #[derive(Clone, Copy)]
24 fn level(self) -> Level {
26 ParentId::Def(_) => Level::Direct,
27 ParentId::Import(_) => Level::Reexported,
32 pub struct EffectiveVisibilitiesVisitor<'r, 'a> {
33 r: &'r mut Resolver<'a>,
34 def_effective_visibilities: EffectiveVisibilities,
35 /// While walking import chains we need to track effective visibilities per-binding, and def id
36 /// keys in `Resolver::effective_visibilities` are not enough for that, because multiple
37 /// bindings can correspond to a single def id in imports. So we keep a separate table.
38 import_effective_visibilities: EffectiveVisibilities<ImportId<'a>>,
39 // It's possible to recalculate this at any point, but it's relatively expensive.
40 current_private_vis: Visibility,
45 fn nearest_normal_mod(&mut self, def_id: LocalDefId) -> LocalDefId {
46 self.get_nearest_non_block_module(def_id.to_def_id()).nearest_parent_mod().expect_local()
49 fn private_vis_import(&mut self, binding: ImportId<'_>) -> Visibility {
50 let NameBindingKind::Import { import, .. } = binding.kind else { unreachable!() };
51 Visibility::Restricted(
54 .map(|id| self.nearest_normal_mod(self.local_def_id(id)))
55 .unwrap_or(CRATE_DEF_ID),
59 fn private_vis_def(&mut self, def_id: LocalDefId) -> Visibility {
60 // For mod items `nearest_normal_mod` returns its argument, but we actually need its parent.
61 let normal_mod_id = self.nearest_normal_mod(def_id);
62 if normal_mod_id == def_id {
63 self.opt_local_parent(def_id).map_or(Visibility::Public, Visibility::Restricted)
65 Visibility::Restricted(normal_mod_id)
70 impl<'a, 'b> IntoDefIdTree for &'b mut Resolver<'a> {
71 type Tree = &'b Resolver<'a>;
72 fn tree(self) -> Self::Tree {
77 impl<'r, 'a> EffectiveVisibilitiesVisitor<'r, 'a> {
78 /// Fills the `Resolver::effective_visibilities` table with public & exported items
79 /// For now, this doesn't resolve macros (FIXME) and cannot resolve Impl, as we
80 /// need access to a TyCtxt for that.
81 pub fn compute_effective_visibilities<'c>(r: &'r mut Resolver<'a>, krate: &'c Crate) {
82 let mut visitor = EffectiveVisibilitiesVisitor {
84 def_effective_visibilities: Default::default(),
85 import_effective_visibilities: Default::default(),
86 current_private_vis: Visibility::Public,
90 visitor.update(CRATE_DEF_ID, CRATE_DEF_ID);
91 visitor.current_private_vis = Visibility::Restricted(CRATE_DEF_ID);
92 visitor.set_bindings_effective_visibilities(CRATE_DEF_ID);
94 while visitor.changed {
95 visitor.changed = false;
96 visit::walk_crate(&mut visitor, krate);
98 visitor.r.effective_visibilities = visitor.def_effective_visibilities;
100 // Update visibilities for import def ids. These are not used during the
101 // `EffectiveVisibilitiesVisitor` pass, because we have more detailed binding-based
102 // information, but are used by later passes. Effective visibility of an import def id
103 // is the maximum value among visibilities of bindings corresponding to that def id.
104 for (binding, eff_vis) in visitor.import_effective_visibilities.iter() {
105 let NameBindingKind::Import { import, .. } = binding.kind else { unreachable!() };
106 if let Some(node_id) = import.id() {
107 r.effective_visibilities.update_eff_vis(
108 r.local_def_id(node_id),
110 ResolverTree(&r.untracked),
115 info!("resolve::effective_visibilities: {:#?}", r.effective_visibilities);
118 /// Update effective visibilities of bindings in the given module,
119 /// including their whole reexport chains.
120 fn set_bindings_effective_visibilities(&mut self, module_id: LocalDefId) {
121 assert!(self.r.module_map.contains_key(&&module_id.to_def_id()));
122 let module = self.r.get_module(module_id.to_def_id()).unwrap();
123 let resolutions = self.r.resolutions(module);
125 for (_, name_resolution) in resolutions.borrow().iter() {
126 if let Some(mut binding) = name_resolution.borrow().binding() && !binding.is_ambiguity() {
127 // Set the given effective visibility level to `Level::Direct` and
128 // sets the rest of the `use` chain to `Level::Reexported` until
129 // we hit the actual exported item.
130 let mut parent_id = ParentId::Def(module_id);
131 while let NameBindingKind::Import { binding: nested_binding, .. } = binding.kind {
132 let binding_id = ImportId::new_unchecked(binding);
133 self.update_import(binding_id, parent_id);
135 parent_id = ParentId::Import(binding_id);
136 binding = nested_binding;
139 if let Some(def_id) = binding.res().opt_def_id().and_then(|id| id.as_local()) {
140 self.update_def(def_id, binding.vis.expect_local(), parent_id);
146 fn cheap_private_vis(&self, parent_id: ParentId<'_>) -> Option<Visibility> {
147 matches!(parent_id, ParentId::Def(_)).then_some(self.current_private_vis)
150 fn effective_vis_or_private(&mut self, parent_id: ParentId<'a>) -> EffectiveVisibility {
151 // Private nodes are only added to the table for caching, they could be added or removed at
152 // any moment without consequences, so we don't set `changed` to true when adding them.
154 ParentId::Def(def_id) => self
155 .def_effective_visibilities
156 .effective_vis_or_private(def_id, || self.r.private_vis_def(def_id)),
157 ParentId::Import(binding) => self
158 .import_effective_visibilities
159 .effective_vis_or_private(binding, || self.r.private_vis_import(binding)),
163 fn update_import(&mut self, binding: ImportId<'a>, parent_id: ParentId<'a>) {
164 let nominal_vis = binding.vis.expect_local();
165 let private_vis = self.cheap_private_vis(parent_id);
166 let inherited_eff_vis = self.effective_vis_or_private(parent_id);
167 self.changed |= self.import_effective_visibilities.update(
170 |r| (private_vis.unwrap_or_else(|| r.private_vis_import(binding)), r),
177 fn update_def(&mut self, def_id: LocalDefId, nominal_vis: Visibility, parent_id: ParentId<'a>) {
178 let private_vis = self.cheap_private_vis(parent_id);
179 let inherited_eff_vis = self.effective_vis_or_private(parent_id);
180 self.changed |= self.def_effective_visibilities.update(
183 |r| (private_vis.unwrap_or_else(|| r.private_vis_def(def_id)), r),
190 fn update(&mut self, def_id: LocalDefId, parent_id: LocalDefId) {
191 self.update_def(def_id, self.r.visibilities[&def_id], ParentId::Def(parent_id));
195 impl<'r, 'ast> Visitor<'ast> for EffectiveVisibilitiesVisitor<'ast, 'r> {
196 fn visit_item(&mut self, item: &'ast ast::Item) {
197 let def_id = self.r.local_def_id(item.id);
198 // Update effective visibilities of nested items.
199 // If it's a mod, also make the visitor walk all of its items
201 // Resolved in rustc_privacy when types are available
202 ast::ItemKind::Impl(..) => return,
204 // Should be unreachable at this stage
205 ast::ItemKind::MacCall(..) => panic!(
206 "ast::ItemKind::MacCall encountered, this should not anymore appear at this stage"
209 ast::ItemKind::Mod(..) => {
210 let prev_private_vis =
211 mem::replace(&mut self.current_private_vis, Visibility::Restricted(def_id));
212 self.set_bindings_effective_visibilities(def_id);
213 visit::walk_item(self, item);
214 self.current_private_vis = prev_private_vis;
217 ast::ItemKind::Enum(EnumDef { ref variants }, _) => {
218 self.set_bindings_effective_visibilities(def_id);
219 for variant in variants {
220 let variant_def_id = self.r.local_def_id(variant.id);
221 for field in variant.data.fields() {
222 self.update(self.r.local_def_id(field.id), variant_def_id);
227 ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => {
228 for field in def.fields() {
229 self.update(self.r.local_def_id(field.id), def_id);
233 ast::ItemKind::Trait(..) => {
234 self.set_bindings_effective_visibilities(def_id);
237 ast::ItemKind::ExternCrate(..)
238 | ast::ItemKind::Use(..)
239 | ast::ItemKind::Static(..)
240 | ast::ItemKind::Const(..)
241 | ast::ItemKind::GlobalAsm(..)
242 | ast::ItemKind::TyAlias(..)
243 | ast::ItemKind::TraitAlias(..)
244 | ast::ItemKind::MacroDef(..)
245 | ast::ItemKind::ForeignMod(..)
246 | ast::ItemKind::Fn(..) => return,