split up define into define_extern and define_local

Author: LorrensP-2158466

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -42,20 +42,20 @@ type Res = def::Res<NodeId>;
 impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
     /// otherwise, reports an error.
-    pub(crate) fn define_binding(
+    pub(crate) fn define_binding_local(
         &mut self,
         parent: Module<'ra>,
         ident: Ident,
         ns: Namespace,
         binding: NameBinding<'ra>,
     ) {
         let key = self.new_disambiguated_key(ident, ns);
-        if let Err(old_binding) = self.try_define(parent, key, binding, false) {
+        if let Err(old_binding) = self.try_define_local(parent, key, binding, false) {
             self.report_conflict(parent, ident, ns, old_binding, binding);
         }
     }
 
-    fn define(
+    fn define_local(
         &mut self,
         parent: Module<'ra>,
         ident: Ident,
@@ -66,7 +66,29 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         expn_id: LocalExpnId,
     ) {
         let binding = self.arenas.new_res_binding(res, vis.to_def_id(), span, expn_id);
-        self.define_binding(parent, ident, ns, binding)
+        self.define_binding_local(parent, ident, ns, binding)
+    }
+
+    // Panics when a binding already exists.
+    fn define_extern(
+        &self,
+        parent: Module<'ra>,
+        ident: Ident,
+        ns: Namespace,
+        res: Res,
+        vis: Visibility<impl Into<DefId>>,
+        span: Span,
+        expn_id: LocalExpnId,
+    ) {
+        let binding = self.arenas.new_res_binding(res, vis.to_def_id(), span, expn_id);
+        let key = self.new_disambiguated_key(ident, ns);
+        self.check_reserved_macro_name(key.ident, binding.res());
+        let resolution = &mut *self.resolution(parent, key).borrow_mut();
+        if resolution.binding.is_some() {
+            panic!("An external binding was already defined");
+        }
+        // FIXME: maybe some handling of glob-importers
+        resolution.binding = Some(binding);
     }
 
     /// Walks up the tree of definitions starting at `def_id`,
@@ -189,7 +211,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         visitor.parent_scope.macro_rules
     }
 
-    pub(crate) fn build_reduced_graph_external(&mut self, module: Module<'ra>) {
+    pub(crate) fn build_reduced_graph_external(&self, module: Module<'ra>) {
         for child in self.tcx.module_children(module.def_id()) {
             let parent_scope = ParentScope::module(module, self);
             self.build_reduced_graph_for_external_crate_res(child, parent_scope)
@@ -198,7 +220,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
     /// Builds the reduced graph for a single item in an external crate.
     fn build_reduced_graph_for_external_crate_res(
-        &mut self,
+        &self,
         child: &ModChild,
         parent_scope: ParentScope<'ra>,
     ) {
@@ -229,7 +251,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 _,
             )
             | Res::PrimTy(..)
-            | Res::ToolMod => self.define(parent, ident, TypeNS, res, vis, span, expansion),
+            | Res::ToolMod => self.define_extern(parent, ident, TypeNS, res, vis, span, expansion),
             Res::Def(
                 DefKind::Fn
                 | DefKind::AssocFn
@@ -238,9 +260,9 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 | DefKind::AssocConst
                 | DefKind::Ctor(..),
                 _,
-            ) => self.define(parent, ident, ValueNS, res, vis, span, expansion),
+            ) => self.define_extern(parent, ident, ValueNS, res, vis, span, expansion),
             Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
-                self.define(parent, ident, MacroNS, res, vis, span, expansion)
+                self.define_extern(parent, ident, MacroNS, res, vis, span, expansion)
             }
             Res::Def(
                 DefKind::TyParam
@@ -713,7 +735,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         let expansion = parent_scope.expansion;
 
         // Define a name in the type namespace if it is not anonymous.
-        self.r.define(parent, ident, TypeNS, adt_res, adt_vis, adt_span, expansion);
+        self.r.define_local(parent, ident, TypeNS, adt_res, adt_vis, adt_span, expansion);
         self.r.feed_visibility(feed, adt_vis);
         let def_id = feed.key();
 
@@ -765,7 +787,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             }
 
             ItemKind::Mod(_, ident, ref mod_kind) => {
-                self.r.define(parent, ident, TypeNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, TypeNS, res, vis, sp, expansion);
 
                 if let ast::ModKind::Loaded(_, _, _, Err(_)) = mod_kind {
                     self.r.mods_with_parse_errors.insert(def_id);
@@ -784,10 +806,10 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             ItemKind::Const(box ConstItem { ident, .. })
             | ItemKind::Delegation(box Delegation { ident, .. })
             | ItemKind::Static(box StaticItem { ident, .. }) => {
-                self.r.define(parent, ident, ValueNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, ValueNS, res, vis, sp, expansion);
             }
             ItemKind::Fn(box Fn { ident, .. }) => {
-                self.r.define(parent, ident, ValueNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, ValueNS, res, vis, sp, expansion);
 
                 // Functions introducing procedural macros reserve a slot
                 // in the macro namespace as well (see #52225).
@@ -796,11 +818,11 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
 
             // These items live in the type namespace.
             ItemKind::TyAlias(box TyAlias { ident, .. }) | ItemKind::TraitAlias(ident, ..) => {
-                self.r.define(parent, ident, TypeNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, TypeNS, res, vis, sp, expansion);
             }
 
             ItemKind::Enum(ident, _, _) | ItemKind::Trait(box ast::Trait { ident, .. }) => {
-                self.r.define(parent, ident, TypeNS, res, vis, sp, expansion);
+                self.r.define_local(parent, ident, TypeNS, res, vis, sp, expansion);
 
                 self.parent_scope.module = self.r.new_local_module(
                     Some(parent),
@@ -852,7 +874,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                     let feed = self.r.feed(ctor_node_id);
                     let ctor_def_id = feed.key();
                     let ctor_res = self.res(ctor_def_id);
-                    self.r.define(parent, ident, ValueNS, ctor_res, ctor_vis, sp, expansion);
+                    self.r.define_local(parent, ident, ValueNS, ctor_res, ctor_vis, sp, expansion);
                     self.r.feed_visibility(feed, ctor_vis);
                     // We need the field visibility spans also for the constructor for E0603.
                     self.insert_field_visibilities_local(ctor_def_id.to_def_id(), vdata.fields());
@@ -973,7 +995,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                 );
             }
         }
-        self.r.define_binding(parent, ident, TypeNS, imported_binding);
+        self.r.define_binding_local(parent, ident, TypeNS, imported_binding);
     }
 
     /// Constructs the reduced graph for one foreign item.
@@ -990,7 +1012,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         let parent = self.parent_scope.module;
         let expansion = self.parent_scope.expansion;
         let vis = self.resolve_visibility(&item.vis);
-        self.r.define(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
+        self.r.define_local(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
         self.r.feed_visibility(feed, vis);
     }
 
@@ -1249,7 +1271,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
                 });
                 self.r.import_use_map.insert(import, Used::Other);
                 let import_binding = self.r.import(binding, import);
-                self.r.define_binding(self.r.graph_root, ident, MacroNS, import_binding);
+                self.r.define_binding_local(self.r.graph_root, ident, MacroNS, import_binding);
             } else {
                 self.r.check_reserved_macro_name(ident, res);
                 self.insert_unused_macro(ident, def_id, item.id);
@@ -1277,7 +1299,7 @@ impl<'a, 'ra, 'tcx> BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             if !vis.is_public() {
                 self.insert_unused_macro(ident, def_id, item.id);
             }
-            self.r.define(module, ident, MacroNS, res, vis, span, expansion);
+            self.r.define_local(module, ident, MacroNS, res, vis, span, expansion);
             self.r.feed_visibility(feed, vis);
             self.parent_scope.macro_rules
         }
@@ -1413,7 +1435,7 @@ impl<'a, 'ra, 'tcx> Visitor<'a> for BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         if ctxt == AssocCtxt::Trait {
             let parent = self.parent_scope.module;
             let expansion = self.parent_scope.expansion;
-            self.r.define(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
+            self.r.define_local(parent, ident, ns, self.res(def_id), vis, item.span, expansion);
         } else if !matches!(&item.kind, AssocItemKind::Delegation(deleg) if deleg.from_glob) {
             let impl_def_id = self.r.tcx.local_parent(local_def_id);
             let key = BindingKey::new(ident.normalize_to_macros_2_0(), ns);
@@ -1498,7 +1520,7 @@ impl<'a, 'ra, 'tcx> Visitor<'a> for BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
         let feed = self.r.feed(variant.id);
         let def_id = feed.key();
         let vis = self.resolve_visibility(&variant.vis);
-        self.r.define(parent, ident, TypeNS, self.res(def_id), vis, variant.span, expn_id);
+        self.r.define_local(parent, ident, TypeNS, self.res(def_id), vis, variant.span, expn_id);
         self.r.feed_visibility(feed, vis);
 
         // If the variant is marked as non_exhaustive then lower the visibility to within the crate.
@@ -1514,7 +1536,7 @@ impl<'a, 'ra, 'tcx> Visitor<'a> for BuildReducedGraphVisitor<'a, 'ra, 'tcx> {
             let feed = self.r.feed(ctor_node_id);
             let ctor_def_id = feed.key();
             let ctor_res = self.res(ctor_def_id);
-            self.r.define(parent, ident, ValueNS, ctor_res, ctor_vis, variant.span, expn_id);
+            self.r.define_local(parent, ident, ValueNS, ctor_res, ctor_vis, variant.span, expn_id);
             self.r.feed_visibility(feed, ctor_vis);
         }
 

compiler/rustc_resolve/src/imports.rs

@@ -326,9 +326,24 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         })
     }
 
+    // pub(crate) fn try_define(
+    //     &mut self,
+    //     module: Module<'ra>,
+    //     key: BindingKey,
+    //     binding: NameBinding<'ra>,
+    //     warn_ambiguity: bool,
+    // ) -> Result<(), NameBinding<'ra>> {
+    //     if module.is_local_module() {
+    //         self.try_define_local(module, key, binding, warn_ambiguity)
+    //     } else {
+    //         self.define_extern(module, key, binding);
+    //         Ok(())
+    //     }
+    // }
+
     /// Define the name or return the existing binding if there is a collision.
     /// `update` indicates if the definition is a redefinition of an existing binding.
-    pub(crate) fn try_define(
+    pub(crate) fn try_define_local(
         &mut self,
         module: Module<'ra>,
         key: BindingKey,
@@ -477,7 +492,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             if self.is_accessible_from(binding.vis, scope) {
                 let imported_binding = self.import(binding, *import);
                 let key = BindingKey { ident, ..key };
-                let _ = self.try_define(
+                // FIXME: local or external?
+                let _ = self.try_define_local(
                     import.parent_scope.module,
                     key,
                     imported_binding,
@@ -501,7 +517,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             let dummy_binding = self.import(dummy_binding, import);
             self.per_ns(|this, ns| {
                 let key = BindingKey::new(target, ns);
-                let _ = this.try_define(import.parent_scope.module, key, dummy_binding, false);
+                let _ =
+                    this.try_define_local(import.parent_scope.module, key, dummy_binding, false);
                 this.update_resolution(import.parent_scope.module, key, false, |_, resolution| {
                     resolution.single_imports.swap_remove(&import);
                 })
@@ -866,7 +883,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
                         let imported_binding = this.import(binding, import);
                         target_bindings[ns].set(Some(imported_binding));
-                        this.define_binding(parent, target, ns, imported_binding);
+                        this.define_binding_local(parent, target, ns, imported_binding);
                     }
                     Err(Determined) => {
                         // Don't update the resolution for underscores, because it was never added.
@@ -1484,7 +1501,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     .borrow()
                     .binding()
                     .is_some_and(|binding| binding.warn_ambiguity_recursive());
-                let _ = self.try_define(
+                let _ = self.try_define_local(
                     import.parent_scope.module,
                     key,
                     imported_binding,

compiler/rustc_resolve/src/lib.rs

@@ -1078,7 +1078,7 @@ pub struct Resolver<'ra, 'tcx> {
     extern_module_map: RefCell<FxIndexMap<DefId, Module<'ra>>>,
     binding_parent_modules: FxHashMap<NameBinding<'ra>, Module<'ra>>,
 
-    underscore_disambiguator: u32,
+    underscore_disambiguator: Cell<u32>,
 
     /// Maps glob imports to the names of items actually imported.
     glob_map: FxIndexMap<LocalDefId, FxIndexSet<Symbol>>,
@@ -1491,7 +1491,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             extern_crate_map: Default::default(),
             module_children: Default::default(),
             trait_map: NodeMap::default(),
-            underscore_disambiguator: 0,
+            underscore_disambiguator: Cell::new(0),
             empty_module,
             local_module_map,
             extern_module_map: Default::default(),
@@ -1879,18 +1879,18 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
         import_ids
     }
 
-    fn new_disambiguated_key(&mut self, ident: Ident, ns: Namespace) -> BindingKey {
+    fn new_disambiguated_key(&self, ident: Ident, ns: Namespace) -> BindingKey {
         let ident = ident.normalize_to_macros_2_0();
         let disambiguator = if ident.name == kw::Underscore {
-            self.underscore_disambiguator += 1;
-            self.underscore_disambiguator
+            self.underscore_disambiguator.update(|x| x + 1);
+            self.underscore_disambiguator.get()
         } else {
             0
         };
         BindingKey { ident, ns, disambiguator }
     }
 
-    fn resolutions(&mut self, module: Module<'ra>) -> &'ra Resolutions<'ra> {
+    fn resolutions(&self, module: Module<'ra>) -> &'ra Resolutions<'ra> {
         if module.populate_on_access.get() {
             module.populate_on_access.set(false);
             self.build_reduced_graph_external(module);
@@ -1899,7 +1899,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     fn resolution(
-        &mut self,
+        &self,
         module: Module<'ra>,
         key: BindingKey,
     ) -> &'ra RefCell<NameResolution<'ra>> {