use crate::{ImportKind, NameBindingKind, Resolver}; use rustc_ast::ast; use rustc_ast::visit; use rustc_ast::visit::Visitor; use rustc_ast::Crate; use rustc_ast::EnumDef; use rustc_hir::def_id::LocalDefId; use rustc_hir::def_id::CRATE_DEF_ID; use rustc_middle::middle::privacy::Level; use rustc_middle::ty::{DefIdTree, Visibility}; pub struct EffectiveVisibilitiesVisitor<'r, 'a> { r: &'r mut Resolver<'a>, changed: bool, } impl<'r, 'a> EffectiveVisibilitiesVisitor<'r, 'a> { /// Fills the `Resolver::effective_visibilities` 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_effective_visibilities<'c>(r: &'r mut Resolver<'a>, krate: &'c Crate) { let mut visitor = EffectiveVisibilitiesVisitor { r, changed: false }; visitor.update(CRATE_DEF_ID, Visibility::Public, CRATE_DEF_ID, Level::Direct); visitor.set_bindings_effective_visibilities(CRATE_DEF_ID); while visitor.changed { visitor.reset(); visit::walk_crate(&mut visitor, krate); } info!("resolve::effective_visibilities: {:#?}", r.effective_visibilities); } fn reset(&mut self) { self.changed = false; } /// Update effective visibilities of bindings in the given module, /// including their whole reexport chains. fn set_bindings_effective_visibilities(&mut self, module_id: LocalDefId) { assert!(self.r.module_map.contains_key(&&module_id.to_def_id())); let module = self.r.get_module(module_id.to_def_id()).unwrap(); let resolutions = self.r.resolutions(module); for (_, name_resolution) in resolutions.borrow().iter() { if let Some(mut binding) = name_resolution.borrow().binding() && !binding.is_ambiguity() { // Set the given effective visibility level to `Level::Direct` and // sets the rest of the `use` chain to `Level::Reexported` until // we hit the actual exported item. // FIXME: tag and is_public() condition should be removed, but assertions occur. let tag = if binding.is_import() { Level::Reexported } else { Level::Direct }; if binding.vis.is_public() { let mut prev_parent_id = module_id; let mut level = Level::Direct; while let NameBindingKind::Import { binding: nested_binding, import, .. } = binding.kind { let mut update = |node_id| self.update( self.r.local_def_id(node_id), binding.vis.expect_local(), prev_parent_id, level, ); // In theory all the import IDs have individual visibilities and effective // visibilities, but in practice these IDs go straigth to HIR where all // their few uses assume that their (effective) visibility applies to the // whole syntactic `use` item. So we update them all to the maximum value // among the potential individual effective visibilities. Maybe HIR for // imports shouldn't use three IDs at all. update(import.id); if let ImportKind::Single { additional_ids, .. } = import.kind { update(additional_ids.0); update(additional_ids.1); } level = Level::Reexported; prev_parent_id = self.r.local_def_id(import.id); binding = nested_binding; } } if let Some(def_id) = binding.res().opt_def_id().and_then(|id| id.as_local()) { self.update(def_id, binding.vis.expect_local(), module_id, tag); } } } } fn update( &mut self, def_id: LocalDefId, nominal_vis: Visibility, parent_id: LocalDefId, tag: Level, ) { let module_id = self .r .get_nearest_non_block_module(def_id.to_def_id()) .nearest_parent_mod() .expect_local(); if nominal_vis == Visibility::Restricted(module_id) || self.r.visibilities[&parent_id] == Visibility::Restricted(module_id) { return; } let mut effective_visibilities = std::mem::take(&mut self.r.effective_visibilities); self.changed |= effective_visibilities.update( def_id, nominal_vis, || Visibility::Restricted(module_id), parent_id, tag, &*self.r, ); self.r.effective_visibilities = effective_visibilities; } } impl<'r, 'ast> Visitor<'ast> for EffectiveVisibilitiesVisitor<'ast, 'r> { fn visit_item(&mut self, item: &'ast ast::Item) { let def_id = self.r.local_def_id(item.id); // Update effective visibilities of nested items. // If it's a mod, also make the visitor walk all of its items match item.kind { // Resolved in rustc_privacy when types are available ast::ItemKind::Impl(..) => return, // Should be unreachable at this stage ast::ItemKind::MacCall(..) => panic!( "ast::ItemKind::MacCall encountered, this should not anymore appear at this stage" ), // Foreign modules inherit level from parents. ast::ItemKind::ForeignMod(..) => { let parent_id = self.r.local_parent(def_id); self.update(def_id, Visibility::Public, parent_id, Level::Direct); } // Only exported `macro_rules!` items are public, but they always are ast::ItemKind::MacroDef(ref macro_def) if macro_def.macro_rules => { let parent_id = self.r.local_parent(def_id); let vis = self.r.visibilities[&def_id]; self.update(def_id, vis, parent_id, Level::Direct); } ast::ItemKind::Mod(..) => { self.set_bindings_effective_visibilities(def_id); visit::walk_item(self, item); } ast::ItemKind::Enum(EnumDef { ref variants }, _) => { self.set_bindings_effective_visibilities(def_id); for variant in variants { let variant_def_id = self.r.local_def_id(variant.id); for field in variant.data.fields() { let field_def_id = self.r.local_def_id(field.id); let vis = self.r.visibilities[&field_def_id]; self.update(field_def_id, vis, variant_def_id, Level::Direct); } } } ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => { for field in def.fields() { let field_def_id = self.r.local_def_id(field.id); let vis = self.r.visibilities[&field_def_id]; self.update(field_def_id, vis, def_id, Level::Direct); } } ast::ItemKind::Trait(..) => { self.set_bindings_effective_visibilities(def_id); } 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, } } }