Correct comments about untracked accesses.

Author: cjgillot

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -445,7 +445,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
     }
 
     fn encode_def_path_table(&mut self) {
-        let table = self.tcx.hir().definitions().def_path_table();
+        let table = self.tcx.resolutions(()).definitions.def_path_table();
         if self.is_proc_macro {
             for def_index in std::iter::once(CRATE_DEF_INDEX)
                 .chain(self.tcx.hir().krate().proc_macros.iter().map(|p| p.owner.local_def_index))
@@ -1062,7 +1062,7 @@ impl EncodeContext<'a, 'tcx> {
 
         let data = ModData {
             reexports,
-            expansion: tcx.hir().definitions().expansion_that_defined(local_def_id),
+            expansion: tcx.resolutions(()).definitions.expansion_that_defined(local_def_id),
         };
 
         record!(self.tables.kind[def_id] <- EntryKind::Mod(self.lazy(data)));
@@ -1759,7 +1759,7 @@ impl EncodeContext<'a, 'tcx> {
             .map(|(trait_def_id, mut impls)| {
                 // Bring everything into deterministic order for hashing
                 impls.sort_by_cached_key(|&(index, _)| {
-                    tcx.hir().definitions().def_path_hash(LocalDefId { local_def_index: index })
+                    tcx.hir().def_path_hash(LocalDefId { local_def_index: index })
                 });
 
                 TraitImpls {

compiler/rustc_middle/src/hir/map/mod.rs

@@ -9,7 +9,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::svh::Svh;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
-use rustc_hir::definitions::{DefKey, DefPath, Definitions};
+use rustc_hir::definitions::{DefKey, DefPath, DefPathHash};
 use rustc_hir::intravisit;
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
@@ -154,14 +154,8 @@ impl<'hir> Map<'hir> {
         self.tcx.hir_crate(())
     }
 
-    #[inline]
-    pub fn definitions(&self) -> &'hir Definitions {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
-        &self.tcx.untracked_resolutions.definitions
-    }
-
     pub fn def_key(&self, def_id: LocalDefId) -> DefKey {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // Accessing the DefKey is ok, since it is part of DefPathHash.
         self.tcx.untracked_resolutions.definitions.def_key(def_id)
     }
 
@@ -170,10 +164,16 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn def_path(&self, def_id: LocalDefId) -> DefPath {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // Accessing the DefPath is ok, since it is part of DefPathHash.
         self.tcx.untracked_resolutions.definitions.def_path(def_id)
     }
 
+    #[inline]
+    pub fn def_path_hash(self, def_id: LocalDefId) -> DefPathHash {
+        // Accessing the DefPathHash is ok, it is incr. comp. stable.
+        self.tcx.untracked_resolutions.definitions.def_path_hash(def_id)
+    }
+
     #[inline]
     pub fn local_def_id(&self, hir_id: HirId) -> LocalDefId {
         self.opt_local_def_id(hir_id).unwrap_or_else(|| {
@@ -187,18 +187,20 @@ impl<'hir> Map<'hir> {
 
     #[inline]
     pub fn opt_local_def_id(&self, hir_id: HirId) -> Option<LocalDefId> {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // FIXME(#85914) is this access safe for incr. comp.?
         self.tcx.untracked_resolutions.definitions.opt_hir_id_to_local_def_id(hir_id)
     }
 
     #[inline]
     pub fn local_def_id_to_hir_id(&self, def_id: LocalDefId) -> HirId {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // FIXME(#85914) is this access safe for incr. comp.?
         self.tcx.untracked_resolutions.definitions.local_def_id_to_hir_id(def_id)
     }
 
     pub fn iter_local_def_id(&self) -> impl Iterator<Item = LocalDefId> + '_ {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // Create a dependency to the crate to be sure we reexcute this when the amount of
+        // definitions change.
+        self.tcx.ensure().hir_crate(());
         self.tcx.untracked_resolutions.definitions.iter_local_def_id()
     }
 

compiler/rustc_middle/src/ty/context.rs

@@ -1240,9 +1240,9 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn def_key(self, id: DefId) -> rustc_hir::definitions::DefKey {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // Accessing the DefKey is ok, since it is part of DefPathHash.
         if let Some(id) = id.as_local() {
-            self.hir().def_key(id)
+            self.untracked_resolutions.definitions.def_key(id)
         } else {
             self.untracked_resolutions.cstore.def_key(id)
         }
@@ -1254,17 +1254,17 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Note that if `id` is not local to this crate, the result will
     ///  be a non-local `DefPath`.
     pub fn def_path(self, id: DefId) -> rustc_hir::definitions::DefPath {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // Accessing the DefPath is ok, since it is part of DefPathHash.
         if let Some(id) = id.as_local() {
-            self.hir().def_path(id)
+            self.untracked_resolutions.definitions.def_path(id)
         } else {
             self.untracked_resolutions.cstore.def_path(id)
         }
     }
 
     #[inline]
     pub fn def_path_hash(self, def_id: DefId) -> rustc_hir::definitions::DefPathHash {
-        // Accessing the definitions is ok, since all its contents are tracked by the query system.
+        // Accessing the DefPathHash is ok, it is incr. comp. stable.
         if let Some(def_id) = def_id.as_local() {
             self.untracked_resolutions.definitions.def_path_hash(def_id)
         } else {

compiler/rustc_query_impl/src/stats.rs

@@ -108,7 +108,7 @@ pub fn print_stats(tcx: TyCtxt<'_>) {
         queries.iter().filter(|q| q.local_def_id_keys.is_some()).collect();
     def_id_density.sort_by_key(|q| q.local_def_id_keys.unwrap());
     eprintln!("\nLocal DefId density:");
-    let total = tcx.hir().definitions().def_index_count() as f64;
+    let total = tcx.resolutions(()).definitions.def_index_count() as f64;
     for q in def_id_density.iter().rev() {
         let local = q.local_def_id_keys.unwrap();
         eprintln!("   {} - {} = ({}%)", q.name, local, (local as f64 * 100.0) / total);