Remove Symbol for Named LateParam/Bound variants

5 files changed, 90 insertions, 130 deletions

diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 8aa50d14faa..021d0148fd1 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -3279,10 +3279,7 @@ impl<'tcx> TyCtxt<'tcx> {
                     return ty::Region::new_late_param(
                         self,
                         new_parent.to_def_id(),
-                        ty::LateParamRegionKind::Named(
-                            lbv.to_def_id(),
-                            self.item_name(lbv.to_def_id()),
-                        ),
+                        ty::LateParamRegionKind::Named(lbv.to_def_id()),
                     );
                 }
                 resolve_bound_vars::ResolvedArg::Error(guar) => {
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index b4c4f48a0a6..ad463984459 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -11,7 +11,7 @@ use rustc_data_structures::unord::UnordMap;
 use rustc_hir as hir;
 use rustc_hir::LangItem;
 use rustc_hir::def::{self, CtorKind, DefKind, Namespace};
-use rustc_hir::def_id::{CRATE_DEF_ID, DefIdMap, DefIdSet, LOCAL_CRATE, ModDefId};
+use rustc_hir::def_id::{DefIdMap, DefIdSet, LOCAL_CRATE, ModDefId};
 use rustc_hir::definitions::{DefKey, DefPathDataName};
 use rustc_macros::{Lift, extension};
 use rustc_session::Limit;
@@ -2553,12 +2553,12 @@ impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
         match region.kind() {
             ty::ReEarlyParam(ref data) => data.has_name(),
 
-            ty::ReLateParam(ty::LateParamRegion { kind, .. }) => kind.is_named(),
+            ty::ReLateParam(ty::LateParamRegion { kind, .. }) => kind.is_named(self.tcx),
             ty::ReBound(_, ty::BoundRegion { kind: br, .. })
             | ty::RePlaceholder(ty::Placeholder {
                 bound: ty::BoundRegion { kind: br, .. }, ..
             }) => {
-                if br.is_named() {
+                if br.is_named(self.tcx) {
                     return true;
                 }
 
@@ -2626,7 +2626,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
                 return Ok(());
             }
             ty::ReLateParam(ty::LateParamRegion { kind, .. }) => {
-                if let Some(name) = kind.get_name() {
+                if let Some(name) = kind.get_name(self.tcx) {
                     p!(write("{}", name));
                     return Ok(());
                 }
@@ -2635,9 +2635,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
             | ty::RePlaceholder(ty::Placeholder {
                 bound: ty::BoundRegion { kind: br, .. }, ..
             }) => {
-                if let ty::BoundRegionKind::Named(_, name) = br
-                    && br.is_named()
-                {
+                if let Some(name) = br.get_name(self.tcx) {
                     p!(write("{}", name));
                     return Ok(());
                 }
@@ -2844,55 +2842,22 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
             let mut name = |lifetime_idx: Option<ty::DebruijnIndex>,
                             binder_level_idx: ty::DebruijnIndex,
                             br: ty::BoundRegion| {
-                let (name, kind) = match br.kind {
-                    ty::BoundRegionKind::Anon | ty::BoundRegionKind::ClosureEnv => {
-                        let name = next_name(self);
-
-                        if let Some(lt_idx) = lifetime_idx {
-                            if lt_idx > binder_level_idx {
-                                let kind =
-                                    ty::BoundRegionKind::Named(CRATE_DEF_ID.to_def_id(), name);
-                                return ty::Region::new_bound(
-                                    tcx,
-                                    ty::INNERMOST,
-                                    ty::BoundRegion { var: br.var, kind },
-                                );
-                            }
-                        }
-
-                        (name, ty::BoundRegionKind::Named(CRATE_DEF_ID.to_def_id(), name))
-                    }
-                    ty::BoundRegionKind::Named(def_id, kw::UnderscoreLifetime) => {
-                        let name = next_name(self);
-
-                        if let Some(lt_idx) = lifetime_idx {
-                            if lt_idx > binder_level_idx {
-                                let kind = ty::BoundRegionKind::Named(def_id, name);
-                                return ty::Region::new_bound(
-                                    tcx,
-                                    ty::INNERMOST,
-                                    ty::BoundRegion { var: br.var, kind },
-                                );
-                            }
-                        }
-
-                        (name, ty::BoundRegionKind::Named(def_id, name))
-                    }
-                    ty::BoundRegionKind::Named(_, name) => {
-                        if let Some(lt_idx) = lifetime_idx {
-                            if lt_idx > binder_level_idx {
-                                let kind = br.kind;
-                                return ty::Region::new_bound(
-                                    tcx,
-                                    ty::INNERMOST,
-                                    ty::BoundRegion { var: br.var, kind },
-                                );
-                            }
-                        }
+                let (name, kind) = if let Some(name) = br.kind.get_name(tcx) {
+                    (name, br.kind)
+                } else {
+                    let name = next_name(self);
+                    (name, ty::BoundRegionKind::NamedAnon(name))
+                };
 
-                        (name, br.kind)
+                if let Some(lt_idx) = lifetime_idx {
+                    if lt_idx > binder_level_idx {
+                        return ty::Region::new_bound(
+                            tcx,
+                            ty::INNERMOST,
+                            ty::BoundRegion { var: br.var, kind },
+                        );
                     }
-                };
+                }
 
                 // Unconditionally render `unsafe<>`.
                 if !trim_path || mode == WrapBinderMode::Unsafe {
@@ -2960,13 +2925,15 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
         T: TypeFoldable<TyCtxt<'tcx>>,
     {
         struct RegionNameCollector<'tcx> {
+            tcx: TyCtxt<'tcx>,
             used_region_names: FxHashSet<Symbol>,
             type_collector: SsoHashSet<Ty<'tcx>>,
         }
 
         impl<'tcx> RegionNameCollector<'tcx> {
-            fn new() -> Self {
+            fn new(tcx: TyCtxt<'tcx>) -> Self {
                 RegionNameCollector {
+                    tcx,
                     used_region_names: Default::default(),
                     type_collector: SsoHashSet::new(),
                 }
@@ -2980,7 +2947,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
                 // Collect all named lifetimes. These allow us to prevent duplication
                 // of already existing lifetime names when introducing names for
                 // anonymous late-bound regions.
-                if let Some(name) = r.get_name() {
+                if let Some(name) = r.get_name(self.tcx) {
                     self.used_region_names.insert(name);
                 }
             }
@@ -2995,7 +2962,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
             }
         }
 
-        let mut collector = RegionNameCollector::new();
+        let mut collector = RegionNameCollector::new(self.tcx());
         value.visit_with(&mut collector);
         self.used_region_names = collector.used_region_names;
         self.region_index = 0;
diff --git a/compiler/rustc_middle/src/ty/region.rs b/compiler/rustc_middle/src/ty/region.rs
index cc25cd16567..c598cd21fc8 100644
--- a/compiler/rustc_middle/src/ty/region.rs
+++ b/compiler/rustc_middle/src/ty/region.rs
@@ -163,37 +163,33 @@ impl<'tcx> Region<'tcx> {
         *self.0.0
     }
 
-    pub fn get_name(self) -> Option<Symbol> {
-        if self.has_name() {
-            match self.kind() {
-                ty::ReEarlyParam(ebr) => Some(ebr.name),
-                ty::ReBound(_, br) => br.kind.get_name(),
-                ty::ReLateParam(fr) => fr.kind.get_name(),
-                ty::ReStatic => Some(kw::StaticLifetime),
-                ty::RePlaceholder(placeholder) => placeholder.bound.kind.get_name(),
-                _ => None,
-            }
-        } else {
-            None
+    pub fn get_name(self, tcx: TyCtxt<'tcx>) -> Option<Symbol> {
+        match self.kind() {
+            ty::ReEarlyParam(ebr) => Some(ebr.name),
+            ty::ReBound(_, br) => br.kind.get_name(tcx),
+            ty::ReLateParam(fr) => fr.kind.get_name(tcx),
+            ty::ReStatic => Some(kw::StaticLifetime),
+            ty::RePlaceholder(placeholder) => placeholder.bound.kind.get_name(tcx),
+            _ => None,
         }
     }
 
-    pub fn get_name_or_anon(self) -> Symbol {
-        match self.get_name() {
+    pub fn get_name_or_anon(self, tcx: TyCtxt<'tcx>) -> Symbol {
+        match self.get_name(tcx) {
             Some(name) => name,
             None => sym::anon,
         }
     }
 
     /// Is this region named by the user?
-    pub fn has_name(self) -> bool {
+    pub fn has_name(self, tcx: TyCtxt<'tcx>) -> bool {
         match self.kind() {
             ty::ReEarlyParam(ebr) => ebr.has_name(),
-            ty::ReBound(_, br) => br.kind.is_named(),
-            ty::ReLateParam(fr) => fr.kind.is_named(),
+            ty::ReBound(_, br) => br.kind.is_named(tcx),
+            ty::ReLateParam(fr) => fr.kind.is_named(tcx),
             ty::ReStatic => true,
             ty::ReVar(..) => false,
-            ty::RePlaceholder(placeholder) => placeholder.bound.kind.is_named(),
+            ty::RePlaceholder(placeholder) => placeholder.bound.kind.is_named(tcx),
             ty::ReErased => false,
             ty::ReError(_) => false,
         }
@@ -313,7 +309,7 @@ impl<'tcx> Region<'tcx> {
                 Some(tcx.generics_of(binding_item).region_param(ebr, tcx).def_id)
             }
             ty::ReLateParam(ty::LateParamRegion {
-                kind: ty::LateParamRegionKind::Named(def_id, _),
+                kind: ty::LateParamRegionKind::Named(def_id),
                 ..
             }) => Some(def_id),
             _ => None,
@@ -371,11 +367,13 @@ pub enum LateParamRegionKind {
     /// sake of diagnostics in `FnCtxt::sig_of_closure_with_expectation`.
     Anon(u32),
 
-    /// Named region parameters for functions (a in &'a T)
+    /// An anonymous region parameter with a `Symbol` name.
     ///
-    /// The `DefId` is needed to distinguish free regions in
-    /// the event of shadowing.
-    Named(DefId, Symbol),
+    /// Used to give late-bound regions names for things like pretty printing.
+    NamedAnon(u32, Symbol),
+
+    /// Late-bound regions that appear in the AST.
+    Named(DefId),
 
     /// Anonymous region for the implicit env pointer parameter
     /// to a closure
@@ -386,32 +384,30 @@ impl LateParamRegionKind {
     pub fn from_bound(var: BoundVar, br: BoundRegionKind) -> LateParamRegionKind {
         match br {
             BoundRegionKind::Anon => LateParamRegionKind::Anon(var.as_u32()),
-            BoundRegionKind::Named(def_id, name) => LateParamRegionKind::Named(def_id, name),
+            BoundRegionKind::Named(def_id) => LateParamRegionKind::Named(def_id),
             BoundRegionKind::ClosureEnv => LateParamRegionKind::ClosureEnv,
+            BoundRegionKind::NamedAnon(name) => LateParamRegionKind::NamedAnon(var.as_u32(), name),
         }
     }
 
-    pub fn is_named(&self) -> bool {
-        match *self {
-            LateParamRegionKind::Named(_, name) => name != kw::UnderscoreLifetime,
-            _ => false,
-        }
+    pub fn is_named(&self, tcx: TyCtxt<'_>) -> bool {
+        self.get_name(tcx).is_some()
     }
 
-    pub fn get_name(&self) -> Option<Symbol> {
-        if self.is_named() {
-            match *self {
-                LateParamRegionKind::Named(_, name) => return Some(name),
-                _ => unreachable!(),
+    pub fn get_name(&self, tcx: TyCtxt<'_>) -> Option<Symbol> {
+        match *self {
+            LateParamRegionKind::Named(def_id) => {
+                let name = tcx.item_name(def_id);
+                if name != kw::UnderscoreLifetime { Some(name) } else { None }
             }
+            LateParamRegionKind::NamedAnon(_, name) => Some(name),
+            _ => None,
         }
-
-        None
     }
 
     pub fn get_id(&self) -> Option<DefId> {
         match *self {
-            LateParamRegionKind::Named(id, _) => Some(id),
+            LateParamRegionKind::Named(id) => Some(id),
             _ => None,
         }
     }
@@ -423,11 +419,13 @@ pub enum BoundRegionKind {
     /// An anonymous region parameter for a given fn (&T)
     Anon,
 
-    /// Named region parameters for functions (a in &'a T)
+    /// An anonymous region parameter with a `Symbol` name.
     ///
-    /// The `DefId` is needed to distinguish free regions in
-    /// the event of shadowing.
-    Named(DefId, Symbol),
+    /// Used to give late-bound regions names for things like pretty printing.
+    NamedAnon(Symbol),
+
+    /// Late-bound regions that appear in the AST.
+    Named(DefId),
 
     /// Anonymous region for the implicit env pointer parameter
     /// to a closure
@@ -456,35 +454,35 @@ impl core::fmt::Debug for BoundRegion {
         match self.kind {
             BoundRegionKind::Anon => write!(f, "{:?}", self.var),
             BoundRegionKind::ClosureEnv => write!(f, "{:?}.Env", self.var),
-            BoundRegionKind::Named(def, symbol) => {
-                write!(f, "{:?}.Named({:?}, {:?})", self.var, def, symbol)
+            BoundRegionKind::Named(def) => {
+                write!(f, "{:?}.Named({:?})", self.var, def)
+            }
+            BoundRegionKind::NamedAnon(symbol) => {
+                write!(f, "{:?}.NamedAnon({:?})", self.var, symbol)
             }
         }
     }
 }
 
 impl BoundRegionKind {
-    pub fn is_named(&self) -> bool {
-        match *self {
-            BoundRegionKind::Named(_, name) => name != kw::UnderscoreLifetime,
-            _ => false,
-        }
+    pub fn is_named(&self, tcx: TyCtxt<'_>) -> bool {
+        self.get_name(tcx).is_some()
     }
 
-    pub fn get_name(&self) -> Option<Symbol> {
-        if self.is_named() {
-            match *self {
-                BoundRegionKind::Named(_, name) => return Some(name),
-                _ => unreachable!(),
+    pub fn get_name(&self, tcx: TyCtxt<'_>) -> Option<Symbol> {
+        match *self {
+            BoundRegionKind::Named(def_id) => {
+                let name = tcx.item_name(def_id);
+                if name != kw::UnderscoreLifetime { Some(name) } else { None }
             }
+            BoundRegionKind::NamedAnon(name) => Some(name),
+            _ => None,
         }
-
-        None
     }
 
     pub fn get_id(&self) -> Option<DefId> {
         match *self {
-            BoundRegionKind::Named(id, _) => Some(id),
+            BoundRegionKind::Named(id) => Some(id),
             _ => None,
         }
     }
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index 1214731a3b2..3a0bd1fb029 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -69,12 +69,11 @@ impl fmt::Debug for ty::BoundRegionKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             ty::BoundRegionKind::Anon => write!(f, "BrAnon"),
-            ty::BoundRegionKind::Named(did, name) => {
-                if did.is_crate_root() {
-                    write!(f, "BrNamed({name})")
-                } else {
-                    write!(f, "BrNamed({did:?}, {name})")
-                }
+            ty::BoundRegionKind::NamedAnon(name) => {
+                write!(f, "BrNamedAnon({name})")
+            }
+            ty::BoundRegionKind::Named(did) => {
+                write!(f, "BrNamed({did:?})")
             }
             ty::BoundRegionKind::ClosureEnv => write!(f, "BrEnv"),
         }
@@ -91,12 +90,11 @@ impl fmt::Debug for ty::LateParamRegionKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             ty::LateParamRegionKind::Anon(idx) => write!(f, "LateAnon({idx})"),
-            ty::LateParamRegionKind::Named(did, name) => {
-                if did.is_crate_root() {
-                    write!(f, "LateNamed({name})")
-                } else {
-                    write!(f, "LateNamed({did:?}, {name})")
-                }
+            ty::LateParamRegionKind::NamedAnon(idx, name) => {
+                write!(f, "LateNamedAnon({idx:?}, {name})")
+            }
+            ty::LateParamRegionKind::Named(did) => {
+                write!(f, "LateNamed({did:?})")
             }
             ty::LateParamRegionKind::ClosureEnv => write!(f, "LateEnv"),
         }
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 7a1890226c9..ae3b2a90e6a 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -2032,7 +2032,7 @@ mod size_asserts {
 
     use super::*;
     // tidy-alphabetical-start
-    static_assert_size!(ty::RegionKind<'_>, 24);
+    static_assert_size!(ty::RegionKind<'_>, 20);
     static_assert_size!(ty::TyKind<'_>, 24);
     // tidy-alphabetical-end
 }