Auto merge of #108020 - nnethercote:opt-mk_region, r=compiler-errors

Optimize `mk_region`

PR #107869 avoiding some interning under `mk_ty` by special-casing `Ty` variants with simple (integer) bodies. This PR does something similar for regions.

r? `@compiler-errors`

5 files changed, 16 insertions, 22 deletions

diff --git a/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
index 1550958ab8e..d51cc652bfd 100644
--- a/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
@@ -180,20 +180,20 @@ trait TypeOpInfo<'tcx> {
             return;
         };
 
-        let placeholder_region = tcx.mk_region(ty::RePlaceholder(ty::Placeholder {
+        let placeholder_region = tcx.mk_re_placeholder(ty::Placeholder {
             name: placeholder.name,
             universe: adjusted_universe.into(),
-        }));
+        });
 
         let error_region =
             if let RegionElement::PlaceholderRegion(error_placeholder) = error_element {
                 let adjusted_universe =
                     error_placeholder.universe.as_u32().checked_sub(base_universe.as_u32());
                 adjusted_universe.map(|adjusted| {
-                    tcx.mk_region(ty::RePlaceholder(ty::Placeholder {
+                    tcx.mk_re_placeholder(ty::Placeholder {
                         name: error_placeholder.name,
                         universe: adjusted.into(),
-                    }))
+                    })
                 })
             } else {
                 None
@@ -390,7 +390,7 @@ fn try_extract_error_from_fulfill_cx<'tcx>(
         error_region,
         &region_constraints,
         |vid| ocx.infcx.region_var_origin(vid),
-        |vid| ocx.infcx.universe_of_region(ocx.infcx.tcx.mk_region(ty::ReVar(vid))),
+        |vid| ocx.infcx.universe_of_region(ocx.infcx.tcx.mk_re_var(vid)),
     )
 }
 
@@ -411,7 +411,7 @@ fn try_extract_error_from_region_constraints<'tcx>(
                 }
                 // FIXME: Should this check the universe of the var?
                 Constraint::VarSubReg(vid, sup) if sup == placeholder_region => {
-                    Some((infcx.tcx.mk_region(ty::ReVar(vid)), cause.clone()))
+                    Some((infcx.tcx.mk_re_var(vid), cause.clone()))
                 }
                 _ => None,
             }
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index f2693bded59..83fdb6066c6 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -1297,7 +1297,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             let vid = self.to_region_vid(r);
             let scc = self.constraint_sccs.scc(vid);
             let repr = self.scc_representatives[scc];
-            tcx.mk_region(ty::ReVar(repr))
+            tcx.mk_re_var(repr)
         })
     }
 
@@ -1719,7 +1719,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             }
 
             // If not, report an error.
-            let member_region = infcx.tcx.mk_region(ty::ReVar(member_region_vid));
+            let member_region = infcx.tcx.mk_re_var(member_region_vid);
             errors_buffer.push(RegionErrorKind::UnexpectedHiddenRegion {
                 span: m_c.definition_span,
                 hidden_ty: m_c.hidden_ty,
diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index c7b22d5f2e6..bb42301828d 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -91,7 +91,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                     }
                     None => {
                         subst_regions.push(vid);
-                        infcx.tcx.re_error_with_message(
+                        infcx.tcx.mk_re_error_with_message(
                             concrete_type.span,
                             "opaque type with non-universal region substs",
                         )
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 5b7adae66ac..7a05fde47fc 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -137,7 +137,7 @@ pub(crate) fn type_check<'mir, 'tcx>(
     upvars: &[Upvar<'tcx>],
     use_polonius: bool,
 ) -> MirTypeckResults<'tcx> {
-    let implicit_region_bound = infcx.tcx.mk_region(ty::ReVar(universal_regions.fr_fn_body));
+    let implicit_region_bound = infcx.tcx.mk_re_var(universal_regions.fr_fn_body);
     let mut constraints = MirTypeckRegionConstraints {
         placeholder_indices: PlaceholderIndices::default(),
         placeholder_index_to_region: IndexVec::default(),
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index 56930c89b2c..3f254a6b7b6 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -480,10 +480,8 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
                     LangItem::VaList,
                     Some(self.infcx.tcx.def_span(self.mir_def.did)),
                 );
-                let region = self
-                    .infcx
-                    .tcx
-                    .mk_region(ty::ReVar(self.infcx.next_nll_region_var(FR).to_region_vid()));
+                let region =
+                    self.infcx.tcx.mk_re_var(self.infcx.next_nll_region_var(FR).to_region_vid());
                 let va_list_ty = self
                     .infcx
                     .tcx
@@ -636,7 +634,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
                     var: ty::BoundVar::from_usize(bound_vars.len() - 1),
                     kind: ty::BrEnv,
                 };
-                let env_region = ty::ReLateBound(ty::INNERMOST, br);
+                let env_region = tcx.mk_re_late_bound(ty::INNERMOST, br);
                 let closure_ty = tcx.closure_env_ty(def_id, substs, env_region).unwrap();
 
                 // The "inputs" of the closure in the
@@ -748,10 +746,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
     {
         let (value, _map) = self.tcx.replace_late_bound_regions(value, |br| {
             debug!(?br);
-            let liberated_region = self.tcx.mk_region(ty::ReFree(ty::FreeRegion {
-                scope: all_outlive_scope.to_def_id(),
-                bound_region: br.kind,
-            }));
+            let liberated_region = self.tcx.mk_re_free(all_outlive_scope.to_def_id(), br.kind);
             let region_vid = self.next_nll_region_var(origin);
             indices.insert_late_bound_region(liberated_region, region_vid.to_region_vid());
             debug!(?liberated_region, ?region_vid);
@@ -843,7 +838,7 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
     where
         T: TypeFoldable<'tcx>,
     {
-        tcx.fold_regions(value, |region, _| tcx.mk_region(ty::ReVar(self.to_region_vid(region))))
+        tcx.fold_regions(value, |region, _| tcx.mk_re_var(self.to_region_vid(region)))
     }
 }
 
@@ -883,8 +878,7 @@ fn for_each_late_bound_region_in_item<'tcx>(
 
     for bound_var in tcx.late_bound_vars(tcx.hir().local_def_id_to_hir_id(mir_def_id)) {
         let ty::BoundVariableKind::Region(bound_region) = bound_var else { continue; };
-        let liberated_region = tcx
-            .mk_region(ty::ReFree(ty::FreeRegion { scope: mir_def_id.to_def_id(), bound_region }));
+        let liberated_region = tcx.mk_re_free(mir_def_id.to_def_id(), bound_region);
         f(liberated_region);
     }
 }