Auto merge of rust-lang#121089 - oli-obk:create_def_feed, r=cjgillot

Remove `feed_local_def_id`

best reviewed commit by commit

Basically I returned `TyCtxtFeed` from `create_def` and then preserved that in the local caches

based on rust-lang#121084

r? `@petrochenkov`

compiler/rustc_interface/src/queries.rs

@@ -173,7 +173,7 @@ impl<'tcx> Queries<'tcx> {
                 feed.crate_for_resolver(tcx.arena.alloc(Steal::new((krate, pre_configured_attrs))));
                 feed.output_filenames(Arc::new(outputs));
 
-                let feed = tcx.feed_local_def_id(CRATE_DEF_ID);
+                let feed = tcx.feed_local_crate_def_id();
                 feed.def_kind(DefKind::Mod);
             });
             Ok(qcx)

compiler/rustc_middle/src/ty/context.rs

@@ -62,7 +62,7 @@ use rustc_session::config::CrateType;
 use rustc_session::cstore::{CrateStoreDyn, Untracked};
 use rustc_session::lint::Lint;
 use rustc_session::{Limit, MetadataKind, Session};
-use rustc_span::def_id::{DefPathHash, StableCrateId};
+use rustc_span::def_id::{DefPathHash, StableCrateId, CRATE_DEF_ID};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 use rustc_target::abi::{FieldIdx, Layout, LayoutS, TargetDataLayout, VariantIdx};
@@ -76,6 +76,7 @@ use std::cmp::Ordering;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::iter;
+use std::marker::PhantomData;
 use std::mem;
 use std::ops::{Bound, Deref};
 
@@ -522,15 +523,33 @@ pub struct TyCtxtFeed<'tcx, KEY: Copy> {
     key: KEY,
 }
 
+/// The same as `TyCtxtFeed`, but does not contain a `TyCtxt`.
+/// Use this to pass around when you have a `TyCtxt` elsewhere.
+/// Just an optimization to save space and not store hundreds of
+/// `TyCtxtFeed` in the resolver.
+#[derive(Copy, Clone)]
+pub struct Feed<'tcx, KEY: Copy> {
+    _tcx: PhantomData<TyCtxt<'tcx>>,
+    // Do not allow direct access, as downstream code must not mutate this field.
+    key: KEY,
+}
+
+impl<T: fmt::Debug + Copy> fmt::Debug for Feed<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.key.fmt(f)
+    }
+}
+
 impl<'tcx> TyCtxt<'tcx> {
     pub fn feed_unit_query(self) -> TyCtxtFeed<'tcx, ()> {
         TyCtxtFeed { tcx: self, key: () }
     }
     pub fn feed_local_crate(self) -> TyCtxtFeed<'tcx, CrateNum> {
         TyCtxtFeed { tcx: self, key: LOCAL_CRATE }
     }
-    pub fn feed_local_def_id(self, key: LocalDefId) -> TyCtxtFeed<'tcx, LocalDefId> {
-        TyCtxtFeed { tcx: self, key }
+
+    pub fn feed_local_crate_def_id(self) -> TyCtxtFeed<'tcx, LocalDefId> {
+        TyCtxtFeed { tcx: self, key: CRATE_DEF_ID }
     }
 
     /// In order to break cycles involving `AnonConst`, we need to set the expected type by side
@@ -547,6 +566,23 @@ impl<'tcx, KEY: Copy> TyCtxtFeed<'tcx, KEY> {
     pub fn key(&self) -> KEY {
         self.key
     }
+
+    #[inline(always)]
+    pub fn downgrade(self) -> Feed<'tcx, KEY> {
+        Feed { _tcx: PhantomData, key: self.key }
+    }
+}
+
+impl<'tcx, KEY: Copy> Feed<'tcx, KEY> {
+    #[inline(always)]
+    pub fn key(&self) -> KEY {
+        self.key
+    }
+
+    #[inline(always)]
+    pub fn upgrade(self, tcx: TyCtxt<'tcx>) -> TyCtxtFeed<'tcx, KEY> {
+        TyCtxtFeed { tcx, key: self.key }
+    }
 }
 
 impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
@@ -1091,7 +1127,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // needs to be re-evaluated.
         self.dep_graph.read_index(DepNodeIndex::FOREVER_RED_NODE);
 
-        let feed = self.feed_local_def_id(def_id);
+        let feed = TyCtxtFeed { tcx: self, key: def_id };
         feed.def_kind(def_kind);
         // Unique types created for closures participate in type privacy checking.
         // They have visibilities inherited from the module they are defined in.

compiler/rustc_middle/src/ty/mod.rs

@@ -84,7 +84,8 @@ pub use self::consts::{
     Const, ConstData, ConstInt, ConstKind, Expr, ScalarInt, UnevaluatedConst, ValTree,
 };
 pub use self::context::{
-    tls, CtxtInterners, DeducedParamAttrs, FreeRegionInfo, GlobalCtxt, Lift, TyCtxt, TyCtxtFeed,
+    tls, CtxtInterners, DeducedParamAttrs, Feed, FreeRegionInfo, GlobalCtxt, Lift, TyCtxt,
+    TyCtxtFeed,
 };
 pub use self::instance::{Instance, InstanceDef, ShortInstance, UnusedGenericParams};
 pub use self::list::List;

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -25,6 +25,7 @@ use rustc_hir::def::{self, *};
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
 use rustc_metadata::creader::LoadedMacro;
 use rustc_middle::metadata::ModChild;
+use rustc_middle::ty::Feed;
 use rustc_middle::{bug, ty};
 use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
@@ -407,7 +408,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         // Top level use tree reuses the item's id and list stems reuse their parent
         // use tree's ids, so in both cases their visibilities are already filled.
         if nested && !list_stem {
-            self.r.feed_visibility(self.r.local_def_id(id), vis);
+            self.r.feed_visibility(self.r.feed(id), vis);
         }
 
         let mut prefix_iter = parent_prefix
@@ -632,7 +633,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         &mut self,
         fields: &[ast::FieldDef],
         ident: Ident,
-        def_id: LocalDefId,
+        feed: Feed<'tcx, LocalDefId>,
         adt_res: Res,
         adt_vis: ty::Visibility,
         adt_span: Span,
@@ -643,7 +644,8 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
 
         // 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.feed_visibility(def_id, adt_vis);
+        self.r.feed_visibility(feed, adt_vis);
+        let def_id = feed.key();
 
         // Record field names for error reporting.
         self.insert_field_def_ids(def_id, fields);
@@ -653,14 +655,15 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             match &field.ty.kind {
                 ast::TyKind::AnonStruct(id, nested_fields)
                 | ast::TyKind::AnonUnion(id, nested_fields) => {
-                    let local_def_id = self.r.local_def_id(*id);
+                    let feed = self.r.feed(*id);
+                    let local_def_id = feed.key();
                     let def_id = local_def_id.to_def_id();
                     let def_kind = self.r.tcx.def_kind(local_def_id);
                     let res = Res::Def(def_kind, def_id);
                     self.build_reduced_graph_for_struct_variant(
                         &nested_fields,
                         Ident::empty(),
-                        local_def_id,
+                        feed,
                         res,
                         // Anonymous adts inherit visibility from their parent adts.
                         adt_vis,
@@ -680,12 +683,13 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         let ident = item.ident;
         let sp = item.span;
         let vis = self.resolve_visibility(&item.vis);
-        let local_def_id = self.r.local_def_id(item.id);
+        let feed = self.r.feed(item.id);
+        let local_def_id = feed.key();
         let def_id = local_def_id.to_def_id();
         let def_kind = self.r.tcx.def_kind(def_id);
         let res = Res::Def(def_kind, def_id);
 
-        self.r.feed_visibility(local_def_id, vis);
+        self.r.feed_visibility(feed, vis);
 
         match item.kind {
             ItemKind::Use(ref use_tree) => {
@@ -762,7 +766,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 self.build_reduced_graph_for_struct_variant(
                     vdata.fields(),
                     ident,
-                    local_def_id,
+                    feed,
                     res,
                     vis,
                     sp,
@@ -795,10 +799,11 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                         }
                         ret_fields.push(field_vis.to_def_id());
                     }
-                    let ctor_def_id = self.r.local_def_id(ctor_node_id);
+                    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.feed_visibility(ctor_def_id, ctor_vis);
+                    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());
 
@@ -812,7 +817,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 self.build_reduced_graph_for_struct_variant(
                     vdata.fields(),
                     ident,
-                    local_def_id,
+                    feed,
                     res,
                     vis,
                     sp,
@@ -919,7 +924,8 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
 
     /// Constructs the reduced graph for one foreign item.
     fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
-        let local_def_id = self.r.local_def_id(item.id);
+        let feed = self.r.feed(item.id);
+        let local_def_id = feed.key();
         let def_id = local_def_id.to_def_id();
         let ns = match item.kind {
             ForeignItemKind::Fn(..) => ValueNS,
@@ -931,7 +937,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         let expansion = self.parent_scope.expansion;
         let vis = self.resolve_visibility(&item.vis);
         self.r.define(parent, item.ident, ns, (self.res(def_id), vis, item.span, expansion));
-        self.r.feed_visibility(local_def_id, vis);
+        self.r.feed_visibility(feed, vis);
     }
 
     fn build_reduced_graph_for_block(&mut self, block: &Block) {
@@ -1218,7 +1224,8 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
     fn define_macro(&mut self, item: &ast::Item) -> MacroRulesScopeRef<'a> {
         let parent_scope = self.parent_scope;
         let expansion = parent_scope.expansion;
-        let def_id = self.r.local_def_id(item.id);
+        let feed = self.r.feed(item.id);
+        let def_id = feed.key();
         let (res, ident, span, macro_rules) = match &item.kind {
             ItemKind::MacroDef(def) => (self.res(def_id), item.ident, item.span, def.macro_rules),
             ItemKind::Fn(..) => match self.proc_macro_stub(item) {
@@ -1269,7 +1276,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 self.r.check_reserved_macro_name(ident, res);
                 self.insert_unused_macro(ident, def_id, item.id);
             }
-            self.r.feed_visibility(def_id, vis);
+            self.r.feed_visibility(feed, vis);
             let scope = self.r.arenas.alloc_macro_rules_scope(MacroRulesScope::Binding(
                 self.r.arenas.alloc_macro_rules_binding(MacroRulesBinding {
                     parent_macro_rules_scope: parent_scope.macro_rules,
@@ -1293,7 +1300,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 self.insert_unused_macro(ident, def_id, item.id);
             }
             self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
-            self.r.feed_visibility(def_id, vis);
+            self.r.feed_visibility(feed, vis);
             self.parent_scope.macro_rules
         }
     }
@@ -1385,7 +1392,8 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         }
 
         let vis = self.resolve_visibility(&item.vis);
-        let local_def_id = self.r.local_def_id(item.id);
+        let feed = self.r.feed(item.id);
+        let local_def_id = feed.key();
         let def_id = local_def_id.to_def_id();
 
         if !(ctxt == AssocCtxt::Impl
@@ -1395,7 +1403,7 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             // Trait impl item visibility is inherited from its trait when not specified
             // explicitly. In that case we cannot determine it here in early resolve,
             // so we leave a hole in the visibility table to be filled later.
-            self.r.feed_visibility(local_def_id, vis);
+            self.r.feed_visibility(feed, vis);
         }
 
         if ctxt == AssocCtxt::Trait {
@@ -1469,7 +1477,7 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             self.visit_invoc(sf.id);
         } else {
             let vis = self.resolve_visibility(&sf.vis);
-            self.r.feed_visibility(self.r.local_def_id(sf.id), vis);
+            self.r.feed_visibility(self.r.feed(sf.id), vis);
             visit::walk_field_def(self, sf);
         }
     }
@@ -1487,10 +1495,11 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         let ident = variant.ident;
 
         // Define a name in the type namespace.
-        let def_id = self.r.local_def_id(variant.id);
+        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.feed_visibility(def_id, vis);
+        self.r.feed_visibility(feed, vis);
 
         // If the variant is marked as non_exhaustive then lower the visibility to within the crate.
         let ctor_vis =
@@ -1502,10 +1511,11 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
 
         // Define a constructor name in the value namespace.
         if let Some(ctor_node_id) = variant.data.ctor_node_id() {
-            let ctor_def_id = self.r.local_def_id(ctor_node_id);
+            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.feed_visibility(ctor_def_id, ctor_vis);
+            self.r.feed_visibility(feed, ctor_vis);
         }
 
         // Record field names for error reporting.

compiler/rustc_resolve/src/def_collector.rs

@@ -4,6 +4,7 @@ use rustc_ast::*;
 use rustc_expand::expand::AstFragment;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind};
 use rustc_hir::def_id::LocalDefId;
+use rustc_middle::ty::Feed;
 use rustc_span::hygiene::LocalExpnId;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
@@ -26,26 +27,38 @@ struct DefCollector<'a, 'b, 'tcx> {
 }
 
 impl<'a, 'b, 'tcx> DefCollector<'a, 'b, 'tcx> {
-    fn create_def(
+    fn create_def_with_feed(
         &mut self,
         node_id: NodeId,
         name: Symbol,
         def_kind: DefKind,
         span: Span,
-    ) -> LocalDefId {
+    ) -> Feed<'tcx, LocalDefId> {
         let parent_def = self.parent_def;
         debug!(
             "create_def(node_id={:?}, def_kind={:?}, parent_def={:?})",
             node_id, def_kind, parent_def
         );
-        self.resolver.create_def(
-            parent_def,
-            node_id,
-            name,
-            def_kind,
-            self.expansion.to_expn_id(),
-            span.with_parent(None),
-        )
+        self.resolver
+            .create_def(
+                parent_def,
+                node_id,
+                name,
+                def_kind,
+                self.expansion.to_expn_id(),
+                span.with_parent(None),
+            )
+            .downgrade()
+    }
+
+    fn create_def(
+        &mut self,
+        node_id: NodeId,
+        name: Symbol,
+        def_kind: DefKind,
+        span: Span,
+    ) -> LocalDefId {
+        self.create_def_with_feed(node_id, name, def_kind, span).key()
     }
 
     fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_def: LocalDefId, f: F) {

compiler/rustc_resolve/src/late.rs

@@ -3118,7 +3118,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 );
                 rustc_middle::ty::Visibility::Public
             };
-            this.r.feed_visibility(this.r.local_def_id(id), vis);
+            this.r.feed_visibility(this.r.feed(id), vis);
         };
 
         let Some(binding) = binding else {