Auto merge of #140453 - Zoxc:next-disambiguator, r=oli-obk

Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type

This removes `Definitions.next_disambiguator` as it doesn't guarantee deterministic def paths when `create_def` is called in parallel. Instead a new `DisambiguatorState` type is passed as a mutable reference to `create_def` to help create unique def paths. `create_def` calls with distinct  `DisambiguatorState` instances must ensure that that the def paths are unique without its help.

Anon associated types did rely on this global state for uniqueness and are changed to use (method they're defined in + their position in the method return type) as the `DefPathData` to ensure uniqueness. This also means that the method they're defined in appears in error messages, which is nicer.

`DefPathData::NestedStatic` is added to use for nested data inside statics instead of reusing `DefPathData::AnonConst` to avoid conflicts with those.

cc `@oli-obk`

2 files changed, 12 insertions, 9 deletions

diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index d660234618e..2c6c587f9f0 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -35,7 +35,7 @@ use rustc_errors::{
 };
 use rustc_hir::def::{CtorKind, DefKind};
 use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE, LocalDefId};
-use rustc_hir::definitions::Definitions;
+use rustc_hir::definitions::{DefPathData, Definitions, DisambiguatorState};
 use rustc_hir::intravisit::VisitorExt;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{self as hir, Attribute, HirId, Node, TraitCandidate};
@@ -1978,8 +1978,11 @@ impl<'tcx> TyCtxtAt<'tcx> {
         parent: LocalDefId,
         name: Option<Symbol>,
         def_kind: DefKind,
+        override_def_path_data: Option<DefPathData>,
+        disambiguator: &mut DisambiguatorState,
     ) -> TyCtxtFeed<'tcx, LocalDefId> {
-        let feed = self.tcx.create_def(parent, name, def_kind);
+        let feed =
+            self.tcx.create_def(parent, name, def_kind, override_def_path_data, disambiguator);
 
         feed.def_span(self.span);
         feed
@@ -1993,8 +1996,10 @@ impl<'tcx> TyCtxt<'tcx> {
         parent: LocalDefId,
         name: Option<Symbol>,
         def_kind: DefKind,
+        override_def_path_data: Option<DefPathData>,
+        disambiguator: &mut DisambiguatorState,
     ) -> TyCtxtFeed<'tcx, LocalDefId> {
-        let data = def_kind.def_path_data(name);
+        let data = override_def_path_data.unwrap_or_else(|| def_kind.def_path_data(name));
         // The following call has the side effect of modifying the tables inside `definitions`.
         // These very tables are relied on by the incr. comp. engine to decode DepNodes and to
         // decode the on-disk cache.
@@ -2004,12 +2009,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // - has been created by this call to `create_def`.
         // As a consequence, this LocalDefId is always re-created before it is needed by the incr.
         // comp. engine itself.
-        //
-        // This call also writes to the value of the `source_span` query.
-        // This is fine because:
-        // - that query is `eval_always` so we won't miss its result changing;
-        // - this write will have happened before that query is called.
-        let def_id = self.untracked.definitions.write().create_def(parent, data);
+        let def_id = self.untracked.definitions.write().create_def(parent, data, disambiguator);
 
         // This function modifies `self.definitions` using a side-effect.
         // We need to ensure that these side effects are re-run by the incr. comp. engine.
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index b4ef82f6d42..b8da97c42d4 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -38,6 +38,7 @@ use rustc_errors::{Diag, ErrorGuaranteed};
 use rustc_hir::LangItem;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, DocLinkResMap, LifetimeRes, Res};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, LocalDefIdMap};
+use rustc_hir::definitions::DisambiguatorState;
 use rustc_index::IndexVec;
 use rustc_index::bit_set::BitMatrix;
 use rustc_macros::{
@@ -209,6 +210,8 @@ pub struct ResolverAstLowering {
 
     pub node_id_to_def_id: NodeMap<LocalDefId>,
 
+    pub disambiguator: DisambiguatorState,
+
     pub trait_map: NodeMap<Vec<hir::TraitCandidate>>,
     /// List functions and methods for which lifetime elision was successful.
     pub lifetime_elision_allowed: FxHashSet<ast::NodeId>,