diff options
Diffstat (limited to 'compiler/rustc_resolve/src/access_levels.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/access_levels.rs | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/compiler/rustc_resolve/src/access_levels.rs b/compiler/rustc_resolve/src/access_levels.rs new file mode 100644 index 00000000000..60cc4248edc --- /dev/null +++ b/compiler/rustc_resolve/src/access_levels.rs @@ -0,0 +1,237 @@ +use rustc_ast::ast; +use rustc_ast::visit; +use rustc_ast::visit::Visitor; +use rustc_ast::Crate; +use rustc_ast::EnumDef; +use rustc_ast::ForeignMod; +use rustc_ast::NodeId; +use rustc_ast_lowering::ResolverAstLowering; +use rustc_hir::def_id::LocalDefId; +use rustc_hir::def_id::CRATE_DEF_ID; +use rustc_middle::middle::privacy::AccessLevel; +use rustc_middle::ty::Visibility; +use rustc_span::sym; + +use crate::imports::ImportKind; +use crate::BindingKey; +use crate::NameBinding; +use crate::NameBindingKind; +use crate::Resolver; + +pub struct AccessLevelsVisitor<'r, 'a> { + r: &'r mut Resolver<'a>, + prev_level: Option<AccessLevel>, + changed: bool, +} + +impl<'r, 'a> AccessLevelsVisitor<'r, 'a> { + /// Fills the `Resolver::access_levels` table with public & exported items + /// For now, this doesn't resolve macros (FIXME) and cannot resolve Impl, as we + /// need access to a TyCtxt for that. + pub fn compute_access_levels<'c>(r: &'r mut Resolver<'a>, krate: &'c Crate) { + let mut visitor = + AccessLevelsVisitor { r, changed: false, prev_level: Some(AccessLevel::Public) }; + + visitor.set_access_level_def_id(CRATE_DEF_ID, Some(AccessLevel::Public)); + visitor.set_exports_access_level(CRATE_DEF_ID); + + while visitor.changed { + visitor.reset(); + visit::walk_crate(&mut visitor, krate); + } + + tracing::info!("resolve::access_levels: {:#?}", r.access_levels); + } + + fn reset(&mut self) { + self.changed = false; + self.prev_level = Some(AccessLevel::Public); + } + + /// Update the access level of the exports of the given module accordingly. The module access + /// level has to be Exported or Public. + /// This will also follow `use` chains (see PrivacyVisitor::set_import_binding_access_level). + fn set_exports_access_level(&mut self, module_id: LocalDefId) { + assert!(self.r.module_map.contains_key(&&module_id.to_def_id())); + + // Set the given binding access level to `AccessLevel::Public` and + // sets the rest of the `use` chain to `AccessLevel::Exported` until + // we hit the actual exported item. + let set_import_binding_access_level = + |this: &mut Self, mut binding: &NameBinding<'a>, mut access_level| { + while let NameBindingKind::Import { binding: nested_binding, import, .. } = + binding.kind + { + this.set_access_level(import.id, access_level); + if let ImportKind::Single { additional_ids, .. } = import.kind { + this.set_access_level(additional_ids.0, access_level); + this.set_access_level(additional_ids.1, access_level); + } + + access_level = Some(AccessLevel::Exported); + binding = nested_binding; + } + }; + + let module_level = self.r.access_levels.map.get(&module_id).copied(); + assert!(module_level >= Some(AccessLevel::Exported)); + + if let Some(exports) = self.r.reexport_map.get(&module_id) { + let pub_exports = exports + .iter() + .filter(|ex| ex.vis == Visibility::Public) + .cloned() + .collect::<Vec<_>>(); + + let module = self.r.get_module(module_id.to_def_id()).unwrap(); + for export in pub_exports.into_iter() { + if let Some(export_def_id) = export.res.opt_def_id().and_then(|id| id.as_local()) { + self.set_access_level_def_id(export_def_id, Some(AccessLevel::Exported)); + } + + if let Some(ns) = export.res.ns() { + let key = BindingKey { ident: export.ident, ns, disambiguator: 0 }; + let name_res = self.r.resolution(module, key); + if let Some(binding) = name_res.borrow().binding() { + set_import_binding_access_level(self, binding, module_level) + } + } + } + } + } + + /// Sets the access level of the `LocalDefId` corresponding to the given `NodeId`. + /// This function will panic if the `NodeId` does not have a `LocalDefId` + fn set_access_level( + &mut self, + node_id: NodeId, + access_level: Option<AccessLevel>, + ) -> Option<AccessLevel> { + self.set_access_level_def_id(self.r.local_def_id(node_id), access_level) + } + + fn set_access_level_def_id( + &mut self, + def_id: LocalDefId, + access_level: Option<AccessLevel>, + ) -> Option<AccessLevel> { + let old_level = self.r.access_levels.map.get(&def_id).copied(); + if old_level < access_level { + self.r.access_levels.map.insert(def_id, access_level.unwrap()); + self.changed = true; + access_level + } else { + old_level + } + } +} + +impl<'r, 'ast> Visitor<'ast> for AccessLevelsVisitor<'ast, 'r> { + fn visit_item(&mut self, item: &'ast ast::Item) { + let inherited_item_level = match item.kind { + // Resolved in rustc_privacy when types are available + ast::ItemKind::Impl(..) => return, + + // Only exported `macro_rules!` items are public, but they always are + ast::ItemKind::MacroDef(..) => { + let is_macro_export = + item.attrs.iter().any(|attr| attr.has_name(sym::macro_export)); + if is_macro_export { Some(AccessLevel::Public) } else { None } + } + + // Foreign modules inherit level from parents. + ast::ItemKind::ForeignMod(..) => self.prev_level, + + // Other `pub` items inherit levels from parents. + ast::ItemKind::ExternCrate(..) + | ast::ItemKind::Use(..) + | ast::ItemKind::Static(..) + | ast::ItemKind::Const(..) + | ast::ItemKind::Fn(..) + | ast::ItemKind::Mod(..) + | ast::ItemKind::GlobalAsm(..) + | ast::ItemKind::TyAlias(..) + | ast::ItemKind::Enum(..) + | ast::ItemKind::Struct(..) + | ast::ItemKind::Union(..) + | ast::ItemKind::Trait(..) + | ast::ItemKind::TraitAlias(..) => { + if item.vis.kind.is_pub() { + self.prev_level + } else { + None + } + } + + // Should be unreachable at this stage + ast::ItemKind::MacCall(..) => panic!( + "ast::ItemKind::MacCall encountered, this should not anymore appear at this stage" + ), + }; + + let access_level = self.set_access_level(item.id, inherited_item_level); + + // Set access level of nested items. + // If it's a mod, also make the visitor walk all of its items + match item.kind { + ast::ItemKind::Mod(..) => { + if access_level.is_some() { + self.set_exports_access_level(self.r.local_def_id(item.id)); + } + + let orig_level = std::mem::replace(&mut self.prev_level, access_level); + visit::walk_item(self, item); + self.prev_level = orig_level; + } + + ast::ItemKind::ForeignMod(ForeignMod { ref items, .. }) => { + for nested in items { + if nested.vis.kind.is_pub() { + self.set_access_level(nested.id, access_level); + } + } + } + ast::ItemKind::Enum(EnumDef { ref variants }, _) => { + for variant in variants { + let variant_level = self.set_access_level(variant.id, access_level); + if let Some(ctor_id) = variant.data.ctor_id() { + self.set_access_level(ctor_id, access_level); + } + + for field in variant.data.fields() { + self.set_access_level(field.id, variant_level); + } + } + } + ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => { + if let Some(ctor_id) = def.ctor_id() { + self.set_access_level(ctor_id, access_level); + } + + for field in def.fields() { + if field.vis.kind.is_pub() { + self.set_access_level(field.id, access_level); + } + } + } + ast::ItemKind::Trait(ref trait_kind) => { + for nested in trait_kind.items.iter() { + self.set_access_level(nested.id, access_level); + } + } + + ast::ItemKind::ExternCrate(..) + | ast::ItemKind::Use(..) + | ast::ItemKind::Static(..) + | ast::ItemKind::Const(..) + | ast::ItemKind::GlobalAsm(..) + | ast::ItemKind::TyAlias(..) + | ast::ItemKind::TraitAlias(..) + | ast::ItemKind::MacroDef(..) + | ast::ItemKind::Fn(..) => return, + + // Unreachable kinds + ast::ItemKind::Impl(..) | ast::ItemKind::MacCall(..) => unreachable!(), + } + } +} |