small refactor to region error handling

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -848,7 +848,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 return;
             };
 
-            let fn_returns = self.infcx.tcx.return_type_impl_or_dyn_traits(suitable_region.def_id);
+            let fn_returns = self.infcx.tcx.return_type_impl_or_dyn_traits(suitable_region.scope);
 
             let param = if let Some(param) =
                 find_param_with_region(self.infcx.tcx, self.mir_def_id(), f, outlived_f)
@@ -875,15 +875,15 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                     Some(arg),
                     captures,
                     Some((param.param_ty_span, param.param_ty.to_string())),
-                    Some(suitable_region.def_id),
+                    Some(suitable_region.scope),
                 );
                 return;
             }
 
             let Some((alias_tys, alias_span, lt_addition_span)) = self
                 .infcx
                 .tcx
-                .return_type_impl_or_dyn_traits_with_type_alias(suitable_region.def_id)
+                .return_type_impl_or_dyn_traits_with_type_alias(suitable_region.scope)
             else {
                 return;
             };
@@ -1018,18 +1018,20 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             return;
         };
 
-        let Some((ty_sub, _)) =
-            self.infcx.tcx.is_suitable_region(self.mir_def_id(), sub).and_then(|anon_reg| {
-                find_anon_type(self.infcx.tcx, self.mir_def_id(), sub, &anon_reg.bound_region)
-            })
+        let Some((ty_sub, _)) = self
+            .infcx
+            .tcx
+            .is_suitable_region(self.mir_def_id(), sub)
+            .and_then(|_| find_anon_type(self.infcx.tcx, self.mir_def_id(), sub))
         else {
             return;
         };
 
-        let Some((ty_sup, _)) =
-            self.infcx.tcx.is_suitable_region(self.mir_def_id(), sup).and_then(|anon_reg| {
-                find_anon_type(self.infcx.tcx, self.mir_def_id(), sup, &anon_reg.bound_region)
-            })
+        let Some((ty_sup, _)) = self
+            .infcx
+            .tcx
+            .is_suitable_region(self.mir_def_id(), sup)
+            .and_then(|_| find_anon_type(self.infcx.tcx, self.mir_def_id(), sup))
         else {
             return;
         };

compiler/rustc_middle/src/ty/context.rs

@@ -1115,10 +1115,10 @@ impl<'tcx> CommonConsts<'tcx> {
 /// either a `ReEarlyParam` or `ReLateParam`.
 #[derive(Debug)]
 pub struct FreeRegionInfo {
-    /// `LocalDefId` of the free region.
-    pub def_id: LocalDefId,
-    /// the bound region corresponding to free region.
-    pub bound_region: ty::BoundRegionKind,
+    /// `LocalDefId` of the scope.
+    pub scope: LocalDefId,
+    /// the `DefId` of the free region.
+    pub region_def_id: DefId,
     /// checks if bound region is in Impl Item
     pub is_impl_item: bool,
 }
@@ -1979,7 +1979,7 @@ impl<'tcx> TyCtxt<'tcx> {
         generic_param_scope: LocalDefId,
         mut region: Region<'tcx>,
     ) -> Option<FreeRegionInfo> {
-        let (suitable_region_binding_scope, bound_region) = loop {
+        let (suitable_region_binding_scope, region_def_id) = loop {
             let def_id =
                 region.opt_param_def_id(self, generic_param_scope.to_def_id())?.as_local()?;
             let scope = self.local_parent(def_id);
@@ -1989,10 +1989,7 @@ impl<'tcx> TyCtxt<'tcx> {
                 region = self.map_opaque_lifetime_to_parent_lifetime(def_id);
                 continue;
             }
-            break (
-                scope,
-                ty::BoundRegionKind::Named(def_id.into(), self.item_name(def_id.into())),
-            );
+            break (scope, def_id.into());
         };
 
         let is_impl_item = match self.hir_node_by_def_id(suitable_region_binding_scope) {
@@ -2001,7 +1998,7 @@ impl<'tcx> TyCtxt<'tcx> {
             _ => false,
         };
 
-        Some(FreeRegionInfo { def_id: suitable_region_binding_scope, bound_region, is_impl_item })
+        Some(FreeRegionInfo { scope: suitable_region_binding_scope, region_def_id, is_impl_item })
     }
 
     /// Given a `DefId` for an `fn`, return all the `dyn` and `impl` traits in its return type.

compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/different_lifetimes.rs

@@ -63,26 +63,16 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
         }
 
         // Determine whether the sub and sup consist of both anonymous (elided) regions.
-        let anon_reg_sup = self.tcx().is_suitable_region(self.generic_param_scope, sup)?;
+        let sup_info = self.tcx().is_suitable_region(self.generic_param_scope, sup)?;
 
-        let anon_reg_sub = self.tcx().is_suitable_region(self.generic_param_scope, sub)?;
-        let scope_def_id_sup = anon_reg_sup.def_id;
-        let bregion_sup = anon_reg_sup.bound_region;
-        let scope_def_id_sub = anon_reg_sub.def_id;
-        let bregion_sub = anon_reg_sub.bound_region;
+        let sub_info = self.tcx().is_suitable_region(self.generic_param_scope, sub)?;
 
-        let ty_sup = find_anon_type(self.tcx(), self.generic_param_scope, sup, &bregion_sup)?;
+        let ty_sup = find_anon_type(self.tcx(), self.generic_param_scope, sup)?;
 
-        let ty_sub = find_anon_type(self.tcx(), self.generic_param_scope, sub, &bregion_sub)?;
+        let ty_sub = find_anon_type(self.tcx(), self.generic_param_scope, sub)?;
 
-        debug!(
-            "try_report_anon_anon_conflict: found_param1={:?} sup={:?} br1={:?}",
-            ty_sub, sup, bregion_sup
-        );
-        debug!(
-            "try_report_anon_anon_conflict: found_param2={:?} sub={:?} br2={:?}",
-            ty_sup, sub, bregion_sub
-        );
+        debug!("try_report_anon_anon_conflict: found_param1={:?} sup={:?}", ty_sub, sup);
+        debug!("try_report_anon_anon_conflict: found_param2={:?} sub={:?}", ty_sup, sub);
 
         let (ty_sup, ty_fndecl_sup) = ty_sup;
         let (ty_sub, ty_fndecl_sub) = ty_sub;
@@ -93,9 +83,9 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             self.find_param_with_region(sub, sub)?;
 
         let sup_is_ret_type =
-            self.is_return_type_anon(scope_def_id_sup, bregion_sup, ty_fndecl_sup);
+            self.is_return_type_anon(sup_info.scope, sup_info.region_def_id, ty_fndecl_sup);
         let sub_is_ret_type =
-            self.is_return_type_anon(scope_def_id_sub, bregion_sub, ty_fndecl_sub);
+            self.is_return_type_anon(sub_info.scope, sub_info.region_def_id, ty_fndecl_sub);
 
         debug!(
             "try_report_anon_anon_conflict: sub_is_ret_type={:?} sup_is_ret_type={:?}",

compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/find_anon_type.rs

@@ -1,7 +1,7 @@
 use core::ops::ControlFlow;
 
 use rustc_hir as hir;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_middle::hir::map::Map;
 use rustc_middle::hir::nested_filter;
@@ -28,16 +28,15 @@ pub fn find_anon_type<'tcx>(
     tcx: TyCtxt<'tcx>,
     generic_param_scope: LocalDefId,
     region: Region<'tcx>,
-    br: &ty::BoundRegionKind,
 ) -> Option<(&'tcx hir::Ty<'tcx>, &'tcx hir::FnSig<'tcx>)> {
     let anon_reg = tcx.is_suitable_region(generic_param_scope, region)?;
-    let fn_sig = tcx.hir_node_by_def_id(anon_reg.def_id).fn_sig()?;
+    let fn_sig = tcx.hir_node_by_def_id(anon_reg.scope).fn_sig()?;
 
     fn_sig
         .decl
         .inputs
         .iter()
-        .find_map(|arg| find_component_for_bound_region(tcx, arg, br))
+        .find_map(|arg| find_component_for_bound_region(tcx, arg, anon_reg.region_def_id))
         .map(|ty| (ty, fn_sig))
 }
 
@@ -46,9 +45,9 @@ pub fn find_anon_type<'tcx>(
 fn find_component_for_bound_region<'tcx>(
     tcx: TyCtxt<'tcx>,
     arg: &'tcx hir::Ty<'tcx>,
-    br: &ty::BoundRegionKind,
+    region_def_id: DefId,
 ) -> Option<&'tcx hir::Ty<'tcx>> {
-    FindNestedTypeVisitor { tcx, bound_region: *br, current_index: ty::INNERMOST }
+    FindNestedTypeVisitor { tcx, region_def_id, current_index: ty::INNERMOST }
         .visit_ty(arg)
         .break_value()
 }
@@ -62,9 +61,8 @@ fn find_component_for_bound_region<'tcx>(
 // specific part of the type in the error message.
 struct FindNestedTypeVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
-    // The bound_region corresponding to the Refree(freeregion)
-    // associated with the anonymous region we are looking for.
-    bound_region: ty::BoundRegionKind,
+    // The `DefId` of the region we're looking for.
+    region_def_id: DefId,
     current_index: ty::DebruijnIndex,
 }
 
@@ -96,48 +94,39 @@ impl<'tcx> Visitor<'tcx> for FindNestedTypeVisitor<'tcx> {
             hir::TyKind::Ref(lifetime, _) => {
                 // the lifetime of the Ref
                 let hir_id = lifetime.hir_id;
-                match (self.tcx.named_bound_var(hir_id), self.bound_region) {
+                match self.tcx.named_bound_var(hir_id) {
                     // Find the index of the named region that was part of the
                     // error. We will then search the function parameters for a bound
                     // region at the right depth with the same index
-                    (
-                        Some(rbv::ResolvedArg::EarlyBound(id)),
-                        ty::BoundRegionKind::Named(def_id, _),
-                    ) => {
-                        debug!("EarlyBound id={:?} def_id={:?}", id, def_id);
-                        if id.to_def_id() == def_id {
+                    Some(rbv::ResolvedArg::EarlyBound(id)) => {
+                        debug!("EarlyBound id={:?}", id);
+                        if id.to_def_id() == self.region_def_id {
                             return ControlFlow::Break(arg);
                         }
                     }
 
                     // Find the index of the named region that was part of the
                     // error. We will then search the function parameters for a bound
                     // region at the right depth with the same index
-                    (
-                        Some(rbv::ResolvedArg::LateBound(debruijn_index, _, id)),
-                        ty::BoundRegionKind::Named(def_id, _),
-                    ) => {
+                    Some(rbv::ResolvedArg::LateBound(debruijn_index, _, id)) => {
                         debug!(
                             "FindNestedTypeVisitor::visit_ty: LateBound depth = {:?}",
                             debruijn_index
                         );
-                        debug!("LateBound id={:?} def_id={:?}", id, def_id);
-                        if debruijn_index == self.current_index && id.to_def_id() == def_id {
+                        debug!("LateBound id={:?}", id);
+                        if debruijn_index == self.current_index
+                            && id.to_def_id() == self.region_def_id
+                        {
                             return ControlFlow::Break(arg);
                         }
                     }
 
-                    (
-                        Some(
-                            rbv::ResolvedArg::StaticLifetime
-                            | rbv::ResolvedArg::Free(_, _)
-                            | rbv::ResolvedArg::EarlyBound(_)
-                            | rbv::ResolvedArg::LateBound(_, _, _)
-                            | rbv::ResolvedArg::Error(_),
-                        )
-                        | None,
-                        _,
-                    ) => {
+                    Some(
+                        rbv::ResolvedArg::StaticLifetime
+                        | rbv::ResolvedArg::Free(_, _)
+                        | rbv::ResolvedArg::Error(_),
+                    )
+                    | None => {
                         debug!("no arg found");
                     }
                 }
@@ -151,7 +140,7 @@ impl<'tcx> Visitor<'tcx> for FindNestedTypeVisitor<'tcx> {
                 return if intravisit::walk_ty(
                     &mut TyPathVisitor {
                         tcx: self.tcx,
-                        bound_region: self.bound_region,
+                        region_def_id: self.region_def_id,
                         current_index: self.current_index,
                     },
                     arg,
@@ -179,7 +168,7 @@ impl<'tcx> Visitor<'tcx> for FindNestedTypeVisitor<'tcx> {
 // specific part of the type in the error message.
 struct TyPathVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
-    bound_region: ty::BoundRegionKind,
+    region_def_id: DefId,
     current_index: ty::DebruijnIndex,
 }
 
@@ -192,38 +181,29 @@ impl<'tcx> Visitor<'tcx> for TyPathVisitor<'tcx> {
     }
 
     fn visit_lifetime(&mut self, lifetime: &hir::Lifetime) -> Self::Result {
-        match (self.tcx.named_bound_var(lifetime.hir_id), self.bound_region) {
+        match self.tcx.named_bound_var(lifetime.hir_id) {
             // the lifetime of the TyPath!
-            (Some(rbv::ResolvedArg::EarlyBound(id)), ty::BoundRegionKind::Named(def_id, _)) => {
-                debug!("EarlyBound id={:?} def_id={:?}", id, def_id);
-                if id.to_def_id() == def_id {
+            Some(rbv::ResolvedArg::EarlyBound(id)) => {
+                debug!("EarlyBound id={:?}", id);
+                if id.to_def_id() == self.region_def_id {
                     return ControlFlow::Break(());
                 }
             }
 
-            (
-                Some(rbv::ResolvedArg::LateBound(debruijn_index, _, id)),
-                ty::BoundRegionKind::Named(def_id, _),
-            ) => {
+            Some(rbv::ResolvedArg::LateBound(debruijn_index, _, id)) => {
                 debug!("FindNestedTypeVisitor::visit_ty: LateBound depth = {:?}", debruijn_index,);
                 debug!("id={:?}", id);
-                debug!("def_id={:?}", def_id);
-                if debruijn_index == self.current_index && id.to_def_id() == def_id {
+                if debruijn_index == self.current_index && id.to_def_id() == self.region_def_id {
                     return ControlFlow::Break(());
                 }
             }
 
-            (
-                Some(
-                    rbv::ResolvedArg::StaticLifetime
-                    | rbv::ResolvedArg::EarlyBound(_)
-                    | rbv::ResolvedArg::LateBound(_, _, _)
-                    | rbv::ResolvedArg::Free(_, _)
-                    | rbv::ResolvedArg::Error(_),
-                )
-                | None,
-                _,
-            ) => {
+            Some(
+                rbv::ResolvedArg::StaticLifetime
+                | rbv::ResolvedArg::Free(_, _)
+                | rbv::ResolvedArg::Error(_),
+            )
+            | None => {
                 debug!("no arg found");
             }
         }

compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/named_anon_conflict.rs

@@ -54,9 +54,9 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
         let param = anon_param_info.param;
         let new_ty = anon_param_info.param_ty;
         let new_ty_span = anon_param_info.param_ty_span;
-        let br = anon_param_info.bound_region;
+        let br = anon_param_info.br;
         let is_first = anon_param_info.is_first;
-        let scope_def_id = region_info.def_id;
+        let scope_def_id = region_info.scope;
         let is_impl_item = region_info.is_impl_item;
 
         match br {
@@ -73,7 +73,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             return None;
         }
 
-        if find_anon_type(self.tcx(), self.generic_param_scope, anon, &br).is_some()
+        if find_anon_type(self.tcx(), self.generic_param_scope, anon).is_some()
             && self.is_self_anon(is_first, scope_def_id)
         {
             return None;

compiler/rustc_trait_selection/src/error_reporting/infer/nice_region_error/static_impl_trait.rs

@@ -50,7 +50,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                     // This may have a closure and it would cause ICE
                     // through `find_param_with_region` (#78262).
                     let anon_reg_sup = tcx.is_suitable_region(self.generic_param_scope, *sup_r)?;
-                    let fn_returns = tcx.return_type_impl_or_dyn_traits(anon_reg_sup.def_id);
+                    let fn_returns = tcx.return_type_impl_or_dyn_traits(anon_reg_sup.scope);
                     if fn_returns.is_empty() {
                         return None;
                     }
@@ -196,7 +196,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
 
         let mut err = self.tcx().dcx().create_err(diag);
 
-        let fn_returns = tcx.return_type_impl_or_dyn_traits(anon_reg_sup.def_id);
+        let fn_returns = tcx.return_type_impl_or_dyn_traits(anon_reg_sup.scope);
 
         let mut override_error_code = None;
         if let SubregionOrigin::Subtype(box TypeTrace { cause, .. }) = &sup_origin
@@ -250,7 +250,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             Some(arg),
             captures,
             Some((param.param_ty_span, param.param_ty.to_string())),
-            Some(anon_reg_sup.def_id),
+            Some(anon_reg_sup.scope),
         );
 
         let reported = err.emit();