resolve: Use Interned for Module

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -31,7 +31,6 @@ use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::Span;
 
 use std::cell::Cell;
-use std::ptr;
 
 type Res = def::Res<NodeId>;
 
@@ -142,8 +141,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             Some(def_id) => self.macro_def_scope(def_id),
             None => expn_id
                 .as_local()
-                .and_then(|expn_id| self.ast_transform_scopes.get(&expn_id))
+                .and_then(|expn_id| self.ast_transform_scopes.get(&expn_id).copied())
-                .unwrap_or(&self.graph_root),
+                .unwrap_or(self.graph_root),
         }
     }
 
@@ -864,7 +863,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         });
         self.r.potentially_unused_imports.push(import);
         let imported_binding = self.r.import(binding, import);
-        if ptr::eq(parent, self.r.graph_root) {
+        if parent == self.r.graph_root {
             if let Some(entry) = self.r.extern_prelude.get(&ident.normalize_to_macros_2_0()) {
                 if expansion != LocalExpnId::ROOT
                     && orig_name.is_some()

compiler/rustc_resolve/src/diagnostics.rs

@@ -1,5 +1,3 @@
-use std::ptr;
-
 use rustc_ast::expand::StrippedCfgItem;
 use rustc_ast::ptr::P;
 use rustc_ast::visit::{self, Visitor};
@@ -1198,7 +1196,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 // avoid suggesting anything with a hygienic name
                 if ident.name == lookup_ident.name
                     && ns == namespace
-                    && !ptr::eq(in_module, parent_scope.module)
+                    && in_module != parent_scope.module
                     && !ident.span.normalize_to_macros_2_0().from_expansion()
                 {
                     let res = name_binding.res();
@@ -1732,7 +1730,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     pub(crate) fn find_similarly_named_module_or_crate(
         &mut self,
         ident: Symbol,
-        current_module: &Module<'a>,
+        current_module: Module<'a>,
     ) -> Option<Symbol> {
         let mut candidates = self
             .extern_prelude
@@ -1742,7 +1740,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 self.module_map
                     .iter()
                     .filter(|(_, module)| {
-                        current_module.is_ancestor_of(module) && !ptr::eq(current_module, *module)
+                        current_module.is_ancestor_of(**module) && current_module != **module
                     })
                     .flat_map(|(_, module)| module.kind.name()),
             )
@@ -1945,7 +1943,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
 
             suggestion = suggestion.or_else(|| {
-                self.find_similarly_named_module_or_crate(ident.name, &parent_scope.module).map(
+                self.find_similarly_named_module_or_crate(ident.name, parent_scope.module).map(
                     |sugg| {
                         (
                             vec![(ident.span, sugg.to_string())],
@@ -2126,9 +2124,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             crate_module = parent;
         }
 
-        if ModuleOrUniformRoot::same_def(ModuleOrUniformRoot::Module(crate_module), module) {
+        if module == ModuleOrUniformRoot::Module(crate_module) {
-            // Don't make a suggestion if the import was already from the root of the
+            // Don't make a suggestion if the import was already from the root of the crate.
-            // crate.
             return None;
         }
 

compiler/rustc_resolve/src/ident.rs

@@ -11,8 +11,6 @@ use rustc_span::hygiene::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContex
 use rustc_span::symbol::{kw, Ident};
 use rustc_span::{Span, DUMMY_SP};
 
-use std::ptr;
-
 use crate::errors::{ParamKindInEnumDiscriminant, ParamKindInNonTrivialAnonConst};
 use crate::late::{
     ConstantHasGenerics, HasGenericParams, NoConstantGenericsReason, PathSource, Rib, RibKind,
@@ -538,7 +536,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                                         ),
                                     );
                                 }
-                                let misc_flags = if ptr::eq(module, this.graph_root) {
+                                let misc_flags = if module == this.graph_root {
                                     Flags::MISC_SUGGEST_CRATE
                                 } else if module.is_normal() {
                                     Flags::MISC_SUGGEST_SELF

compiler/rustc_resolve/src/imports.rs

@@ -35,7 +35,7 @@ use rustc_span::Span;
 use smallvec::SmallVec;
 
 use std::cell::Cell;
-use std::{mem, ptr};
+use std::mem;
 
 type Res = def::Res<NodeId>;
 
@@ -463,7 +463,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
     pub(crate) fn finalize_imports(&mut self) {
         for module in self.arenas.local_modules().iter() {
-            self.finalize_resolutions_in(module);
+            self.finalize_resolutions_in(*module);
         }
 
         let mut seen_spans = FxHashSet::default();
@@ -537,7 +537,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         exported_ambiguities: FxHashSet<NameBinding<'a>>,
     ) {
         for module in self.arenas.local_modules().iter() {
-            for (key, resolution) in self.resolutions(module).borrow().iter() {
+            for (key, resolution) in self.resolutions(*module).borrow().iter() {
                 let resolution = resolution.borrow();
 
                 if let Some(binding) = resolution.binding {
@@ -812,7 +812,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             PathResult::Module(module) => {
                 // Consistency checks, analogous to `finalize_macro_resolutions`.
                 if let Some(initial_module) = import.imported_module.get() {
-                    if !ModuleOrUniformRoot::same_def(module, initial_module) && no_ambiguity {
+                    if module != initial_module && no_ambiguity {
                         span_bug!(import.span, "inconsistent resolution for an import");
                     }
                 } else if self.privacy_errors.is_empty() {
@@ -914,7 +914,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     }
 
                     if let ModuleOrUniformRoot::Module(module) = module {
-                        if ptr::eq(module, import.parent_scope.module) {
+                        if module == import.parent_scope.module {
                             // Importing a module into itself is not allowed.
                             return Some(UnresolvedImportError {
                                 span: import.span,
@@ -1307,7 +1307,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         if module.is_trait() {
             self.tcx.sess.create_err(ItemsInTraitsAreNotImportable { span: import.span }).emit();
             return;
-        } else if ptr::eq(module, import.parent_scope.module) {
+        } else if module == import.parent_scope.module {
             return;
         } else if is_prelude {
             self.prelude = Some(module);

compiler/rustc_resolve/src/late.rs

@@ -2972,7 +2972,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         F: FnOnce(Ident, String, Option<Symbol>) -> ResolutionError<'a>,
     {
         // If there is a TraitRef in scope for an impl, then the method must be in the trait.
-        let Some((module, _)) = &self.current_trait_ref else { return; };
+        let Some((module, _)) = self.current_trait_ref else { return; };
         ident.span.normalize_to_macros_2_0_and_adjust(module.expansion);
         let key = BindingKey::new(ident, ns);
         let mut binding = self.r.resolution(module, key).try_borrow().ok().and_then(|r| r.binding);

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1593,7 +1593,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             return None;
         }
 
-        let resolutions = self.r.resolutions(module);
+        let resolutions = self.r.resolutions(*module);
         let targets = resolutions
             .borrow()
             .iter()

compiler/rustc_resolve/src/lib.rs

@@ -14,6 +14,7 @@
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(never_type)]
+#![feature(rustc_attrs)]
 #![recursion_limit = "256"]
 #![allow(rustdoc::private_intra_doc_links)]
 #![allow(rustc::potential_query_instability)]
@@ -61,7 +62,7 @@ use rustc_span::{Span, DUMMY_SP};
 use smallvec::{smallvec, SmallVec};
 use std::cell::{Cell, RefCell};
 use std::collections::BTreeSet;
-use std::{fmt, ptr};
+use std::fmt;
 
 use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion};
 use imports::{Import, ImportData, ImportKind, NameResolution};
@@ -365,7 +366,7 @@ impl<'a> LexicalScopeBinding<'a> {
     }
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, PartialEq, Debug)]
 enum ModuleOrUniformRoot<'a> {
     /// Regular module.
     Module(Module<'a>),
@@ -383,23 +384,6 @@ enum ModuleOrUniformRoot<'a> {
     CurrentScope,
 }
 
-impl ModuleOrUniformRoot<'_> {
-    fn same_def(lhs: Self, rhs: Self) -> bool {
-        match (lhs, rhs) {
-            (ModuleOrUniformRoot::Module(lhs), ModuleOrUniformRoot::Module(rhs)) => {
-                ptr::eq(lhs, rhs)
-            }
-            (
-                ModuleOrUniformRoot::CrateRootAndExternPrelude,
-                ModuleOrUniformRoot::CrateRootAndExternPrelude,
-            )
-            | (ModuleOrUniformRoot::ExternPrelude, ModuleOrUniformRoot::ExternPrelude)
-            | (ModuleOrUniformRoot::CurrentScope, ModuleOrUniformRoot::CurrentScope) => true,
-            _ => false,
-        }
-    }
-}
-
 #[derive(Debug)]
 enum PathResult<'a> {
     Module(ModuleOrUniformRoot<'a>),
@@ -530,7 +514,9 @@ struct ModuleData<'a> {
     expansion: ExpnId,
 }
 
-type Module<'a> = &'a ModuleData<'a>;
+#[derive(Clone, Copy, PartialEq)]
+#[rustc_pass_by_value]
+struct Module<'a>(Interned<'a, ModuleData<'a>>);
 
 impl<'a> ModuleData<'a> {
     fn new(
@@ -558,8 +544,10 @@ impl<'a> ModuleData<'a> {
             expansion,
         }
     }
+}
 
-    fn for_each_child<'tcx, R, F>(&'a self, resolver: &mut R, mut f: F)
+impl<'a> Module<'a> {
+    fn for_each_child<'tcx, R, F>(self, resolver: &mut R, mut f: F)
     where
         R: AsMut<Resolver<'a, 'tcx>>,
         F: FnMut(&mut R, Ident, Namespace, NameBinding<'a>),
@@ -572,7 +560,7 @@ impl<'a> ModuleData<'a> {
     }
 
     /// This modifies `self` in place. The traits will be stored in `self.traits`.
-    fn ensure_traits<'tcx, R>(&'a self, resolver: &mut R)
+    fn ensure_traits<'tcx, R>(self, resolver: &mut R)
     where
         R: AsMut<Resolver<'a, 'tcx>>,
     {
@@ -591,7 +579,7 @@ impl<'a> ModuleData<'a> {
         }
     }
 
-    fn res(&self) -> Option<Res> {
+    fn res(self) -> Option<Res> {
         match self.kind {
             ModuleKind::Def(kind, def_id, _) => Some(Res::Def(kind, def_id)),
             _ => None,
@@ -599,11 +587,11 @@ impl<'a> ModuleData<'a> {
     }
 
     // Public for rustdoc.
-    fn def_id(&self) -> DefId {
+    fn def_id(self) -> DefId {
         self.opt_def_id().expect("`ModuleData::def_id` is called on a block module")
     }
 
-    fn opt_def_id(&self) -> Option<DefId> {
+    fn opt_def_id(self) -> Option<DefId> {
         match self.kind {
             ModuleKind::Def(_, def_id, _) => Some(def_id),
             _ => None,
@@ -611,15 +599,15 @@ impl<'a> ModuleData<'a> {
     }
 
     // `self` resolves to the first module ancestor that `is_normal`.
-    fn is_normal(&self) -> bool {
+    fn is_normal(self) -> bool {
         matches!(self.kind, ModuleKind::Def(DefKind::Mod, _, _))
     }
 
-    fn is_trait(&self) -> bool {
+    fn is_trait(self) -> bool {
         matches!(self.kind, ModuleKind::Def(DefKind::Trait, _, _))
     }
 
-    fn nearest_item_scope(&'a self) -> Module<'a> {
+    fn nearest_item_scope(self) -> Module<'a> {
         match self.kind {
             ModuleKind::Def(DefKind::Enum | DefKind::Trait, ..) => {
                 self.parent.expect("enum or trait module without a parent")
@@ -630,15 +618,15 @@ impl<'a> ModuleData<'a> {
 
     /// The [`DefId`] of the nearest `mod` item ancestor (which may be this module).
     /// This may be the crate root.
-    fn nearest_parent_mod(&self) -> DefId {
+    fn nearest_parent_mod(self) -> DefId {
         match self.kind {
             ModuleKind::Def(DefKind::Mod, def_id, _) => def_id,
             _ => self.parent.expect("non-root module without parent").nearest_parent_mod(),
         }
     }
 
-    fn is_ancestor_of(&self, mut other: &Self) -> bool {
+    fn is_ancestor_of(self, mut other: Self) -> bool {
-        while !ptr::eq(self, other) {
+        while self != other {
             if let Some(parent) = other.parent {
                 other = parent;
             } else {
@@ -649,7 +637,15 @@ impl<'a> ModuleData<'a> {
     }
 }
 
-impl<'a> fmt::Debug for ModuleData<'a> {
+impl<'a> std::ops::Deref for Module<'a> {
+    type Target = ModuleData<'a>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<'a> fmt::Debug for Module<'a> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:?}", self.res())
     }
@@ -810,10 +806,9 @@ impl<'a> NameBindingData<'a> {
             NameBindingKind::Import { import, .. } => {
                 matches!(import.kind, ImportKind::ExternCrate { .. })
             }
-            NameBindingKind::Module(&ModuleData {
+            NameBindingKind::Module(module)
-                kind: ModuleKind::Def(DefKind::Mod, def_id, _),
+                if let ModuleKind::Def(DefKind::Mod, def_id, _) = module.kind
-                ..
+                    => def_id.is_crate_root(),
-            }) => def_id.is_crate_root(),
             _ => false,
         }
     }
@@ -1102,8 +1097,13 @@ impl<'a> ResolverArenas<'a> {
         no_implicit_prelude: bool,
         module_map: &mut FxHashMap<DefId, Module<'a>>,
     ) -> Module<'a> {
-        let module =
+        let module = Module(Interned::new_unchecked(self.modules.alloc(ModuleData::new(
-            self.modules.alloc(ModuleData::new(parent, kind, expn_id, span, no_implicit_prelude));
+            parent,
+            kind,
+            expn_id,
+            span,
+            no_implicit_prelude,
+        ))));
         let def_id = module.opt_def_id();
         if def_id.map_or(true, |def_id| def_id.is_local()) {
             self.local_modules.borrow_mut().push(module);
@@ -1647,7 +1647,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             module.populate_on_access.set(false);
             self.build_reduced_graph_external(module);
         }
-        &module.lazy_resolutions
+        &module.0.0.lazy_resolutions
     }
 
     fn resolution(
@@ -1827,7 +1827,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
     fn set_binding_parent_module(&mut self, binding: NameBinding<'a>, module: Module<'a>) {
         if let Some(old_module) = self.binding_parent_modules.insert(binding, module) {
-            if !ptr::eq(module, old_module) {
+            if module != old_module {
                 span_bug!(binding.span, "parent module is reset for binding");
             }
         }
@@ -1847,7 +1847,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         ) {
             (Some(macro_rules), Some(modularized)) => {
                 macro_rules.nearest_parent_mod() == modularized.nearest_parent_mod()
-                    && modularized.is_ancestor_of(macro_rules)
+                    && modularized.is_ancestor_of(*macro_rules)
             }
             _ => false,
         }