Return ty::Region in object_lifetime_map.

Author: cjgillot

compiler/rustc_middle/src/query/mod.rs

@@ -1595,7 +1595,7 @@ rustc_queries! {
         desc { "looking up lifetime defaults for a region on an item" }
     }
     /// Fetch the lifetimes for all the trait objects in an item-like.
-    query object_lifetime_map(_: LocalDefId) -> FxHashMap<ItemLocalId, Region> {
+    query object_lifetime_map(_: LocalDefId) -> FxHashMap<ItemLocalId, ty::Region<'tcx>> {
         storage(ArenaCacheSelector<'tcx>)
         desc { "looking up lifetime defaults for a region on an item" }
     }

compiler/rustc_typeck/src/astconv/mod.rs

@@ -204,7 +204,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         let tcx = self.tcx();
 
         let r = if let Some(rl) = tcx.named_region(lifetime.hir_id) {
-            self.ast_region_to_region_inner(rl)
+            Self::ast_region_to_region_inner(tcx, rl)
         } else {
             self.re_infer(def, lifetime.span).unwrap_or_else(|| {
                 debug!(?lifetime, "unelided lifetime in signature");
@@ -226,9 +226,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         r
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
-    fn ast_region_to_region_inner(&self, lifetime: rl::Region) -> ty::Region<'tcx> {
-        let tcx = self.tcx();
+    #[tracing::instrument(level = "debug", skip(tcx))]
+    pub fn ast_region_to_region_inner(tcx: TyCtxt<'tcx>, lifetime: rl::Region) -> ty::Region<'tcx> {
         let lifetime_name = |def_id| tcx.hir().name(tcx.hir().local_def_id_to_hir_id(def_id));
 
         let r = match lifetime {
@@ -1547,33 +1546,33 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         // Use explicitly-specified region bound.
         let region_bound = if !lifetime.is_elided() {
             self.ast_region_to_region(lifetime, None)
+        } else if let Some(region) =
+            self.compute_object_lifetime_bound(span, existential_predicates)
+        {
+            region
+        } else if let Some(rl) = tcx.named_region(lifetime.hir_id) {
+            Self::ast_region_to_region_inner(self.tcx(), rl)
+        } else if let Some(&region) =
+            tcx.object_lifetime_map(lifetime.hir_id.owner).get(&lifetime.hir_id.local_id)
+        {
+            region
         } else {
-            self.compute_object_lifetime_bound(span, existential_predicates).unwrap_or_else(|| {
-                if let Some(rl) = tcx.named_region(lifetime.hir_id) {
-                    self.ast_region_to_region_inner(rl)
-                } else if let Some(&rl) =
-                    tcx.object_lifetime_map(lifetime.hir_id.owner).get(&lifetime.hir_id.local_id)
-                {
-                    self.ast_region_to_region_inner(rl)
-                } else {
-                    self.re_infer(None, span).unwrap_or_else(|| {
-                        let mut err = struct_span_err!(
-                            tcx.sess,
-                            span,
-                            E0228,
-                            "the lifetime bound for this object type cannot be deduced \
+            self.re_infer(None, span).unwrap_or_else(|| {
+                let mut err = struct_span_err!(
+                    tcx.sess,
+                    span,
+                    E0228,
+                    "the lifetime bound for this object type cannot be deduced \
                              from context; please supply an explicit bound"
-                        );
-                        if borrowed {
-                            // We will have already emitted an error E0106 complaining about a
-                            // missing named lifetime in `&dyn Trait`, so we elide this one.
-                            err.delay_as_bug();
-                        } else {
-                            err.emit();
-                        }
-                        tcx.lifetimes.re_static
-                    })
+                );
+                if borrowed {
+                    // We will have already emitted an error E0106 complaining about a
+                    // missing named lifetime in `&dyn Trait`, so we elide this one.
+                    err.delay_as_bug();
+                } else {
+                    err.emit();
                 }
+                tcx.lifetimes.re_static
             })
         };
         debug!("region_bound: {:?}", region_bound);

compiler/rustc_typeck/src/collect/object_lifetime_defaults.rs

@@ -1,3 +1,4 @@
+use crate::AstConv;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -8,7 +9,7 @@ use rustc_hir::{GenericArg, GenericParamKind, LifetimeName, Node};
 use rustc_middle::bug;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_lifetime::*;
-use rustc_middle::ty::{DefIdTree, GenericParamDefKind, TyCtxt};
+use rustc_middle::ty::{self, DefIdTree, GenericParamDefKind, TyCtxt};
 use rustc_span::symbol::sym;
 use std::borrow::Cow;
 
@@ -128,7 +129,7 @@ fn object_lifetime_defaults_for_item<'tcx>(
 pub(super) fn object_lifetime_map(
     tcx: TyCtxt<'_>,
     def_id: LocalDefId,
-) -> FxHashMap<ItemLocalId, Region> {
+) -> FxHashMap<ItemLocalId, ty::Region<'_>> {
     let mut named_region_map = Default::default();
     let mut visitor = LifetimeContext { tcx, defs: &mut named_region_map, scope: ROOT_SCOPE };
     let node = tcx.hir().get_by_def_id(def_id);
@@ -160,7 +161,7 @@ impl RegionExt for Region {
 
 struct LifetimeContext<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
-    defs: &'a mut FxHashMap<ItemLocalId, Region>,
+    defs: &'a mut FxHashMap<ItemLocalId, ty::Region<'tcx>>,
     scope: ScopeRef<'a>,
 }
 
@@ -586,6 +587,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             }
         };
         let def = lifetime.shifted(late_depth);
+        let def = <dyn AstConv<'tcx>>::ast_region_to_region_inner(self.tcx, def);
         debug!(?def);
         self.defs.insert(lifetime_ref.hir_id.local_id, def);
     }