resolve: Use `Interned` for `Import`

5 files changed, 58 insertions, 71 deletions

diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index 9af06f1a48a..fdf1e281b0b 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -6,7 +6,7 @@
 //! Imports are also considered items and placed into modules here, but not resolved yet.
 
 use crate::def_collector::collect_definitions;
-use crate::imports::{Import, ImportKind};
+use crate::imports::{ImportData, ImportKind};
 use crate::macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef};
 use crate::Namespace::{self, MacroNS, TypeNS, ValueNS};
 use crate::{errors, BindingKey, MacroData, NameBindingData};
@@ -354,7 +354,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         vis: ty::Visibility,
     ) {
         let current_module = self.parent_scope.module;
-        let import = self.r.arenas.alloc_import(Import {
+        let import = self.r.arenas.alloc_import(ImportData {
             kind,
             parent_scope: self.parent_scope,
             module_path,
@@ -378,7 +378,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                     if !type_ns_only || ns == TypeNS {
                         let key = BindingKey::new(target, ns);
                         let mut resolution = this.resolution(current_module, key).borrow_mut();
-                        resolution.add_single_import(import);
+                        resolution.single_imports.insert(import);
                     }
                 });
             }
@@ -848,7 +848,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             (used, Some(ModuleOrUniformRoot::Module(module)), binding)
         })
         .unwrap_or((true, None, self.r.dummy_binding));
-        let import = self.r.arenas.alloc_import(Import {
+        let import = self.r.arenas.alloc_import(ImportData {
             kind: ImportKind::ExternCrate { source: orig_name, target: ident, id: item.id },
             root_id: item.id,
             parent_scope: self.parent_scope,
@@ -1058,7 +1058,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         }
 
         let macro_use_import = |this: &Self, span| {
-            this.r.arenas.alloc_import(Import {
+            this.r.arenas.alloc_import(ImportData {
                 kind: ImportKind::MacroUse,
                 root_id: item.id,
                 parent_scope: this.parent_scope,
@@ -1228,7 +1228,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             self.r.set_binding_parent_module(binding, parent_scope.module);
             self.r.all_macro_rules.insert(ident.name, res);
             if is_macro_export {
-                let import = self.r.arenas.alloc_import(Import {
+                let import = self.r.arenas.alloc_import(ImportData {
                     kind: ImportKind::MacroExport,
                     root_id: item.id,
                     parent_scope: self.parent_scope,
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 4db4108c6f4..9c1d4251465 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -262,7 +262,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
         // See https://github.com/rust-lang/rust/issues/32354
         use NameBindingKind::Import;
-        let can_suggest = |binding: NameBinding<'_>, import: &self::Import<'_>| {
+        let can_suggest = |binding: NameBinding<'_>, import: self::Import<'_>| {
             !binding.span.is_dummy()
                 && !matches!(import.kind, ImportKind::MacroUse | ImportKind::MacroExport)
         };
@@ -272,22 +272,22 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             (Import { import: new, .. }, Import { import: old, .. })
                 if {
                     (new.has_attributes || old.has_attributes)
-                        && can_suggest(old_binding, old)
-                        && can_suggest(new_binding, new)
+                        && can_suggest(old_binding, *old)
+                        && can_suggest(new_binding, *new)
                 } =>
             {
                 if old.has_attributes {
-                    Some((new, new_binding.span, true))
+                    Some((*new, new_binding.span, true))
                 } else {
-                    Some((old, old_binding.span, true))
+                    Some((*old, old_binding.span, true))
                 }
             }
             // Otherwise prioritize the new binding.
-            (Import { import, .. }, other) if can_suggest(new_binding, import) => {
-                Some((import, new_binding.span, other.is_import()))
+            (Import { import, .. }, other) if can_suggest(new_binding, *import) => {
+                Some((*import, new_binding.span, other.is_import()))
             }
-            (other, Import { import, .. }) if can_suggest(old_binding, import) => {
-                Some((import, old_binding.span, other.is_import()))
+            (other, Import { import, .. }) if can_suggest(old_binding, *import) => {
+                Some((*import, old_binding.span, other.is_import()))
             }
             _ => None,
         };
@@ -341,7 +341,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         &self,
         err: &mut Diagnostic,
         name: Symbol,
-        import: &Import<'_>,
+        import: Import<'_>,
         binding_span: Span,
     ) {
         let suggested_name = if name.as_str().chars().next().unwrap().is_uppercase() {
@@ -413,7 +413,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     fn add_suggestion_for_duplicate_nested_use(
         &self,
         err: &mut Diagnostic,
-        import: &Import<'_>,
+        import: Import<'_>,
         binding_span: Span,
     ) {
         assert!(import.is_nested());
@@ -2114,7 +2114,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     /// ```
     pub(crate) fn check_for_module_export_macro(
         &mut self,
-        import: &'a Import<'a>,
+        import: Import<'a>,
         module: ModuleOrUniformRoot<'a>,
         ident: Ident,
     ) -> Option<(Option<Suggestion>, Option<String>)> {
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index ba6f50ef1ba..40eee48e475 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -20,7 +20,7 @@ use crate::late::{
 use crate::macros::{sub_namespace_match, MacroRulesScope};
 use crate::BindingKey;
 use crate::{errors, AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, Determinacy, Finalize};
-use crate::{Import, ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot};
+use crate::{ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot};
 use crate::{NameBinding, NameBindingKind, ParentScope, PathResult, PrivacyError, Res};
 use crate::{ResolutionError, Resolver, Scope, ScopeSet, Segment, ToNameBinding, Weak};
 
@@ -913,11 +913,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
 
             if !restricted_shadowing && binding.expansion != LocalExpnId::ROOT {
-                if let NameBindingKind::Import {
-                    import: Import { kind: ImportKind::MacroExport, .. },
-                    ..
-                } = binding.kind
-                {
+                if let NameBindingKind::Import { import, .. } = binding.kind
+                    && matches!(import.kind, ImportKind::MacroExport) {
                     self.macro_expanded_macro_export_errors.insert((path_span, binding.span));
                 }
             }
@@ -951,7 +948,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
             if let Some(ignored) = ignore_binding &&
                 let NameBindingKind::Import { import, .. } = ignored.kind &&
-                ptr::eq(import, &**single_import) {
+                import == *single_import {
                 // Ignore not just the binding itself, but if it has a shadowed_glob,
                 // ignore that, too, because this loop is supposed to only process
                 // named imports.
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 5f5b49d8564..fa8c15abc4b 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -135,7 +135,7 @@ impl<'a> std::fmt::Debug for ImportKind<'a> {
 
 /// One import.
 #[derive(Debug, Clone)]
-pub(crate) struct Import<'a> {
+pub(crate) struct ImportData<'a> {
     pub kind: ImportKind<'a>,
 
     /// Node ID of the "root" use item -- this is always the same as `ImportKind`'s `id`
@@ -172,7 +172,9 @@ pub(crate) struct Import<'a> {
     pub used: Cell<bool>,
 }
 
-impl<'a> Import<'a> {
+pub(crate) type Import<'a> = Interned<'a, ImportData<'a>>;
+
+impl<'a> ImportData<'a> {
     pub(crate) fn is_glob(&self) -> bool {
         matches!(self.kind, ImportKind::Glob { .. })
     }
@@ -214,7 +216,7 @@ impl<'a> Import<'a> {
 pub(crate) struct NameResolution<'a> {
     /// Single imports that may define the name in the namespace.
     /// Imports are arena-allocated, so it's ok to use pointers as keys.
-    pub single_imports: FxHashSet<Interned<'a, Import<'a>>>,
+    pub single_imports: FxHashSet<Import<'a>>,
     /// The least shadowable known binding for this name, or None if there are no known bindings.
     pub binding: Option<NameBinding<'a>>,
     pub shadowed_glob: Option<NameBinding<'a>>,
@@ -231,10 +233,6 @@ impl<'a> NameResolution<'a> {
             }
         })
     }
-
-    pub(crate) fn add_single_import(&mut self, import: &'a Import<'a>) {
-        self.single_imports.insert(Interned::new_unchecked(import));
-    }
 }
 
 /// An error that may be transformed into a diagnostic later. Used to combine multiple unresolved
@@ -250,15 +248,12 @@ struct UnresolvedImportError {
 
 // Reexports of the form `pub use foo as bar;` where `foo` is `extern crate foo;`
 // are permitted for backward-compatibility under a deprecation lint.
-fn pub_use_of_private_extern_crate_hack(import: &Import<'_>, binding: NameBinding<'_>) -> bool {
+fn pub_use_of_private_extern_crate_hack(import: Import<'_>, binding: NameBinding<'_>) -> bool {
     match (&import.kind, &binding.kind) {
-        (
-            ImportKind::Single { .. },
-            NameBindingKind::Import {
-                import: Import { kind: ImportKind::ExternCrate { .. }, .. },
-                ..
-            },
-        ) => import.expect_vis().is_public(),
+        (ImportKind::Single { .. }, NameBindingKind::Import { import: binding_import, .. }) => {
+            matches!(binding_import.kind, ImportKind::ExternCrate { .. })
+                && import.expect_vis().is_public()
+        }
         _ => false,
     }
 }
@@ -266,11 +261,7 @@ fn pub_use_of_private_extern_crate_hack(import: &Import<'_>, binding: NameBindin
 impl<'a, 'tcx> Resolver<'a, 'tcx> {
     /// Given a binding and an import that resolves to it,
     /// return the corresponding binding defined by the import.
-    pub(crate) fn import(
-        &self,
-        binding: NameBinding<'a>,
-        import: &'a Import<'a>,
-    ) -> NameBinding<'a> {
+    pub(crate) fn import(&self, binding: NameBinding<'a>, import: Import<'a>) -> NameBinding<'a> {
         let import_vis = import.expect_vis().to_def_id();
         let vis = if binding.vis.is_at_least(import_vis, self.tcx)
             || pub_use_of_private_extern_crate_hack(import, binding)
@@ -411,7 +402,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 None => continue,
             };
             if self.is_accessible_from(binding.vis, scope) {
-                let imported_binding = self.import(binding, import);
+                let imported_binding = self.import(binding, *import);
                 let key = BindingKey { ident, ..key };
                 let _ = self.try_define(import.parent_scope.module, key, imported_binding);
             }
@@ -422,7 +413,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
     // Define a dummy resolution containing a `Res::Err` as a placeholder for a failed
     // or indeterminate resolution, also mark such failed imports as used to avoid duplicate diagnostics.
-    fn import_dummy_binding(&mut self, import: &'a Import<'a>, is_indeterminate: bool) {
+    fn import_dummy_binding(&mut self, import: Import<'a>, is_indeterminate: bool) {
         if let ImportKind::Single { target, ref target_bindings, .. } = import.kind {
             if !(is_indeterminate || target_bindings.iter().all(|binding| binding.get().is_none()))
             {
@@ -460,7 +451,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             prev_indeterminate_count = indeterminate_count;
             indeterminate_count = 0;
             for import in mem::take(&mut self.indeterminate_imports) {
-                let import_indeterminate_count = self.resolve_import(&import);
+                let import_indeterminate_count = self.resolve_import(import);
                 indeterminate_count += import_indeterminate_count;
                 match import_indeterminate_count {
                     0 => self.determined_imports.push(import),
@@ -609,7 +600,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
     }
 
-    fn throw_unresolved_import_error(&mut self, errors: Vec<(&Import<'_>, UnresolvedImportError)>) {
+    fn throw_unresolved_import_error(&mut self, errors: Vec<(Import<'_>, UnresolvedImportError)>) {
         if errors.is_empty() {
             return;
         }
@@ -701,7 +692,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     ///
     /// Meanwhile, if resolve successful, the resolved bindings are written
     /// into the module.
-    fn resolve_import(&mut self, import: &'a Import<'a>) -> usize {
+    fn resolve_import(&mut self, import: Import<'a>) -> usize {
         debug!(
             "(resolving import for module) resolving import `{}::...` in `{}`",
             Segment::names_to_string(&import.module_path),
@@ -781,7 +772,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         }
                         let key = BindingKey::new(target, ns);
                         this.update_resolution(parent, key, |_, resolution| {
-                            resolution.single_imports.remove(&Interned::new_unchecked(import));
+                            resolution.single_imports.remove(&import);
                         });
                     }
                 }
@@ -795,7 +786,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     ///
     /// Optionally returns an unresolved import error. This error is buffered and used to
     /// consolidate multiple unresolved import errors into a single diagnostic.
-    fn finalize_import(&mut self, import: &'a Import<'a>) -> Option<UnresolvedImportError> {
+    fn finalize_import(&mut self, import: Import<'a>) -> Option<UnresolvedImportError> {
         let orig_vis = import.vis.take();
         let ignore_binding = match &import.kind {
             ImportKind::Single { target_bindings, .. } => target_bindings[TypeNS].get(),
@@ -1239,7 +1230,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     fn check_for_redundant_imports(
         &mut self,
         ident: Ident,
-        import: &'a Import<'a>,
+        import: Import<'a>,
         source_bindings: &PerNS<Cell<Result<NameBinding<'a>, Determinacy>>>,
         target_bindings: &PerNS<Cell<Option<NameBinding<'a>>>>,
         target: Ident,
@@ -1302,7 +1293,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
     }
 
-    fn resolve_glob_import(&mut self, import: &'a Import<'a>) {
+    fn resolve_glob_import(&mut self, import: Import<'a>) {
         // This function is only called for glob imports.
         let ImportKind::Glob { id, is_prelude, .. } = import.kind else { unreachable!() };
 
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 8fefbe8177e..8ee0c715a0e 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -64,7 +64,7 @@ use std::collections::BTreeSet;
 use std::{fmt, ptr};
 
 use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion};
-use imports::{Import, ImportKind, NameResolution};
+use imports::{Import, ImportData, ImportKind, NameResolution};
 use late::{HasGenericParams, PathSource, PatternSource};
 use macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef};
 
@@ -518,8 +518,8 @@ struct ModuleData<'a> {
     /// Whether `#[no_implicit_prelude]` is active.
     no_implicit_prelude: bool,
 
-    glob_importers: RefCell<Vec<&'a Import<'a>>>,
-    globs: RefCell<Vec<&'a Import<'a>>>,
+    glob_importers: RefCell<Vec<Import<'a>>>,
+    globs: RefCell<Vec<Import<'a>>>,
 
     /// Used to memoize the traits in this module for faster searches through all traits in scope.
     traits: RefCell<Option<Box<[(Ident, NameBinding<'a>)]>>>,
@@ -681,7 +681,7 @@ impl<'a> ToNameBinding<'a> for NameBinding<'a> {
 enum NameBindingKind<'a> {
     Res(Res),
     Module(Module<'a>),
-    Import { binding: NameBinding<'a>, import: &'a Import<'a>, used: Cell<bool> },
+    Import { binding: NameBinding<'a>, import: Import<'a>, used: Cell<bool> },
 }
 
 impl<'a> NameBindingKind<'a> {
@@ -807,10 +807,9 @@ impl<'a> NameBindingData<'a> {
 
     fn is_extern_crate(&self) -> bool {
         match self.kind {
-            NameBindingKind::Import {
-                import: &Import { kind: ImportKind::ExternCrate { .. }, .. },
-                ..
-            } => true,
+            NameBindingKind::Import { import, .. } => {
+                matches!(import.kind, ImportKind::ExternCrate { .. })
+            }
             NameBindingKind::Module(&ModuleData {
                 kind: ModuleKind::Def(DefKind::Mod, def_id, _),
                 ..
@@ -919,10 +918,10 @@ pub struct Resolver<'a, 'tcx> {
     field_visibility_spans: FxHashMap<DefId, Vec<Span>>,
 
     /// All imports known to succeed or fail.
-    determined_imports: Vec<&'a Import<'a>>,
+    determined_imports: Vec<Import<'a>>,
 
     /// All non-determined imports.
-    indeterminate_imports: Vec<&'a Import<'a>>,
+    indeterminate_imports: Vec<Import<'a>>,
 
     // Spans for local variables found during pattern resolution.
     // Used for suggestions during error reporting.
@@ -1032,7 +1031,7 @@ pub struct Resolver<'a, 'tcx> {
     /// Avoid duplicated errors for "name already defined".
     name_already_seen: FxHashMap<Symbol, Span>,
 
-    potentially_unused_imports: Vec<&'a Import<'a>>,
+    potentially_unused_imports: Vec<Import<'a>>,
 
     /// Table for mapping struct IDs into struct constructor IDs,
     /// it's not used during normal resolution, only for better error reporting.
@@ -1087,7 +1086,7 @@ pub struct Resolver<'a, 'tcx> {
 pub struct ResolverArenas<'a> {
     modules: TypedArena<ModuleData<'a>>,
     local_modules: RefCell<Vec<Module<'a>>>,
-    imports: TypedArena<Import<'a>>,
+    imports: TypedArena<ImportData<'a>>,
     name_resolutions: TypedArena<RefCell<NameResolution<'a>>>,
     ast_paths: TypedArena<ast::Path>,
     dropless: DroplessArena,
@@ -1120,8 +1119,8 @@ impl<'a> ResolverArenas<'a> {
     fn alloc_name_binding(&'a self, name_binding: NameBindingData<'a>) -> NameBinding<'a> {
         Interned::new_unchecked(self.dropless.alloc(name_binding))
     }
-    fn alloc_import(&'a self, import: Import<'a>) -> &'a Import<'_> {
-        self.imports.alloc(import)
+    fn alloc_import(&'a self, import: ImportData<'a>) -> Import<'a> {
+        Interned::new_unchecked(self.imports.alloc(import))
     }
     fn alloc_name_resolution(&'a self) -> &'a RefCell<NameResolution<'a>> {
         self.name_resolutions.alloc(Default::default())
@@ -1626,7 +1625,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 self.maybe_unused_trait_imports.insert(def_id);
                 import_ids.push(def_id);
             }
-            self.add_to_glob_map(&import, trait_name);
+            self.add_to_glob_map(*import, trait_name);
             kind = &binding.kind;
         }
         import_ids
@@ -1711,13 +1710,13 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             if let Some(id) = import.id() {
                 self.used_imports.insert(id);
             }
-            self.add_to_glob_map(&import, ident);
+            self.add_to_glob_map(import, ident);
             self.record_use(ident, binding, false);
         }
     }
 
     #[inline]
-    fn add_to_glob_map(&mut self, import: &Import<'_>, ident: Ident) {
+    fn add_to_glob_map(&mut self, import: Import<'_>, ident: Ident) {
         if let ImportKind::Glob { id, .. } = import.kind {
             let def_id = self.local_def_id(id);
             self.glob_map.entry(def_id).or_default().insert(ident.name);