Simplify bound var resolution.

Author: cjgillot

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -11,10 +11,13 @@ use std::fmt;
 
 use rustc_ast::visit::walk_list;
 use rustc_data_structures::fx::{FxHashSet,FxIndexMap,FxIndexSet};
+use rustc_data_structures::sorted_map::SortedMap;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind,Res};
 use rustc_hir::intravisit::{self,Visitor};
-use rustc_hir::{GenericArg,GenericParam,GenericParamKind,HirId,HirIdMap,LifetimeName,Node};
+use rustc_hir::{
+GenericArg,GenericParam,GenericParamKind,HirId,ItemLocalMap,LifetimeName,Node,
+};
 use rustc_macros::extension;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_bound_vars::*;
@@ -74,15 +77,15 @@ impl ResolvedArg {
 structNamedVarMap{
 // maps from every use of a named (not anonymous) bound var to a
 // `ResolvedArg` describing how that variable is bound
-defs:HirIdMap<ResolvedArg>,
+defs:ItemLocalMap<ResolvedArg>,
 
 // Maps relevant hir items to the bound vars on them. These include:
 // - function defs
 // - function pointers
 // - closures
 // - trait refs
 // - bound types (like `T` in `for<'a> T<'a>: Foo`)
-late_bound_vars:HirIdMap<Vec<ty::BoundVariableKind>>,
+late_bound_vars:ItemLocalMap<Vec<ty::BoundVariableKind>>,
 }
 
 structBoundVarContext<'a,'tcx>{
@@ -225,10 +228,10 @@ pub(crate) fn provide(providers: &mut Providers) {
 *providers = Providers{
  resolve_bound_vars,
 
-named_variable_map: |tcx, id| tcx.resolve_bound_vars(id).defs.get(&id),
+named_variable_map: |tcx, id| &tcx.resolve_bound_vars(id).defs,
  is_late_bound_map,
  object_lifetime_default,
-late_bound_vars_map: |tcx, id| tcx.resolve_bound_vars(id).late_bound_vars.get(&id),
+late_bound_vars_map: |tcx, id| &tcx.resolve_bound_vars(id).late_bound_vars,
 
  ..*providers
 };
@@ -265,16 +268,12 @@ fn resolve_bound_vars(tcx: TyCtxt<'_>, local_def_id: hir::OwnerId) -> ResolveBou
  hir::OwnerNode::Synthetic => unreachable!(),
 }
 
-letmut rl = ResolveBoundVars::default();
-
-for(hir_id, v)in named_variable_map.defs{
-let map = rl.defs.entry(hir_id.owner).or_default();
- map.insert(hir_id.local_id, v);
-}
-for(hir_id, v)in named_variable_map.late_bound_vars{
-let map = rl.late_bound_vars.entry(hir_id.owner).or_default();
- map.insert(hir_id.local_id, v);
-}
+let defs = named_variable_map.defs.into_sorted_stable_ord();
+let late_bound_vars = named_variable_map.late_bound_vars.into_sorted_stable_ord();
+let rl = ResolveBoundVars{
+defs:SortedMap::from_presorted_elements(defs),
+late_bound_vars:SortedMap::from_presorted_elements(late_bound_vars),
+};
 
 debug!(?rl.defs);
 debug!(?rl.late_bound_vars);
@@ -340,7 +339,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
 Scope::Binder{ hir_id, .. } => {
 // Nested poly trait refs have the binders concatenated
 letmut full_binders =
-self.map.late_bound_vars.entry(*hir_id).or_default().clone();
+self.map.late_bound_vars.entry(hir_id.local_id).or_default().clone();
  full_binders.extend(supertrait_bound_vars);
 break(full_binders,BinderScopeType::Concatenating);
 }
@@ -677,7 +676,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
  hir::TyKind::Ref(lifetime_ref,ref mt) => {
 self.visit_lifetime(lifetime_ref);
 let scope = Scope::ObjectLifetimeDefault{
-lifetime:self.map.defs.get(&lifetime_ref.hir_id).cloned(),
+lifetime:self.map.defs.get(&lifetime_ref.hir_id.local_id).cloned(),
 s:self.scope,
 };
 self.with(scope, |this| this.visit_ty(mt.ty));
@@ -704,7 +703,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
 // and ban them. Type variables instantiated inside binders aren't
 // well-supported at the moment, so this doesn't work.
 // In the future, this should be fixed and this error should be removed.
-let def = self.map.defs.get(&lifetime.hir_id).copied();
+let def = self.map.defs.get(&lifetime.hir_id.local_id).copied();
 letSome(ResolvedArg::LateBound(_, _, lifetime_def_id)) = def else{continue};
 let lifetime_hir_id = self.tcx.local_def_id_to_hir_id(lifetime_def_id);
 
@@ -841,7 +840,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
 let bound_vars:Vec<_> =
 self.tcx.fn_sig(sig_id).skip_binder().bound_vars().iter().collect();
 let hir_id = self.tcx.local_def_id_to_hir_id(def_id);
-self.map.late_bound_vars.insert(hir_id, bound_vars);
+self.map.late_bound_vars.insert(hir_id.local_id, bound_vars);
 }
 self.visit_fn_like_elision(fd.inputs, output,matches!(fk, intravisit::FnKind::Closure));
  intravisit::walk_fn_kind(self, fk);
@@ -1019,10 +1018,10 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
 }
 
 fnrecord_late_bound_vars(&mutself,hir_id:HirId,binder:Vec<ty::BoundVariableKind>){
-ifletSome(old) = self.map.late_bound_vars.insert(hir_id, binder){
+ifletSome(old) = self.map.late_bound_vars.insert(hir_id.local_id, binder){
 bug!(
 "overwrote bound vars for {hir_id:?}:\nold={old:?}\nnew={:?}",
-self.map.late_bound_vars[&hir_id]
+self.map.late_bound_vars[&hir_id.local_id]
 )
 }
 }
@@ -1381,9 +1380,9 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
  kind.descr(param_def_id.to_def_id())
 ),
 };
-self.map.defs.insert(hir_id,ResolvedArg::Error(guar));
+self.map.defs.insert(hir_id.local_id,ResolvedArg::Error(guar));
 }else{
-self.map.defs.insert(hir_id, def);
+self.map.defs.insert(hir_id.local_id, def);
 }
 return;
 }
@@ -1416,7 +1415,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
 bug!("unexpected def-kind: {}", kind.descr(param_def_id.to_def_id()))
 }
 });
-self.map.defs.insert(hir_id,ResolvedArg::Error(guar));
+self.map.defs.insert(hir_id.local_id,ResolvedArg::Error(guar));
 return;
 }
 Scope::Root{ .. } => break,
@@ -1526,7 +1525,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
 // This index can be used with `generic_args` since `parent_count == 0`.
 let index = generics.param_def_id_to_index[&param_def_id]asusize;
  generic_args.args.get(index).and_then(|arg| match arg {
-GenericArg::Lifetime(lt) => map.defs.get(&lt.hir_id).copied(),
+GenericArg::Lifetime(lt) => map.defs.get(&lt.hir_id.local_id).copied(),
  _ => None,
 })
 }
@@ -1816,7 +1815,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
 #[instrument(level = "debug", skip(self))]
 fninsert_lifetime(&mutself,lifetime_ref:&'tcx hir::Lifetime,def:ResolvedArg){
 debug!(span = ?lifetime_ref.ident.span);
-self.map.defs.insert(lifetime_ref.hir_id, def);
+self.map.defs.insert(lifetime_ref.hir_id.local_id, def);
 }
 
 /// Sometimes we resolve a lifetime, but later find that it is an
@@ -1827,8 +1826,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
 lifetime_ref:&'tcx hir::Lifetime,
 bad_def:ResolvedArg,
 ){
-// FIXME(#120456) - is `swap_remove` correct?
-let old_value = self.map.defs.swap_remove(&lifetime_ref.hir_id);
+let old_value = self.map.defs.remove(&lifetime_ref.hir_id.local_id);
 assert_eq!(old_value,Some(bad_def));
 }
 
@@ -1998,7 +1996,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
 // See where these vars are used in `HirTyLowerer::lower_ty_maybe_return_type_notation`.
 // And this is exercised in:
 // `tests/ui/associated-type-bounds/return-type-notation/higher-ranked-bound-works.rs`.
-let existing_bound_vars = self.map.late_bound_vars.get_mut(&hir_id).unwrap();
+let existing_bound_vars = self.map.late_bound_vars.get_mut(&hir_id.local_id).unwrap();
 let existing_bound_vars_saved = existing_bound_vars.clone();
  existing_bound_vars.extend(bound_vars);
 self.record_late_bound_vars(item_segment.hir_id, existing_bound_vars_saved);

compiler/rustc_middle/src/middle/resolve_bound_vars.rs

@@ -1,9 +1,9 @@
 //! Name resolution for lifetimes and late-bound type and const variables: type declarations.
 
-use rustc_data_structures::fx::FxIndexMap;
+use rustc_data_structures::sorted_map::SortedMap;
 use rustc_errors::ErrorGuaranteed;
+use rustc_hir::ItemLocalId;
 use rustc_hir::def_id::{DefId,LocalDefId};
-use rustc_hir::{ItemLocalId,OwnerId};
 use rustc_macros::{Decodable,Encodable,HashStable,TyDecodable,TyEncodable};
 
 usecrate::ty;
@@ -47,11 +47,11 @@ pub enum ObjectLifetimeDefault {
 
 /// Maps the id of each lifetime reference to the lifetime decl
 /// that it corresponds to.
-#[derive(Default,HashStable,Debug)]
+#[derive(HashStable,Debug)]
 pubstructResolveBoundVars{
 /// Maps from every use of a named (not anonymous) lifetime to a
 /// `Region` describing how that region is bound
-pubdefs:FxIndexMap<OwnerId,FxIndexMap<ItemLocalId,ResolvedArg>>,
+pubdefs:SortedMap<ItemLocalId,ResolvedArg>,
 
-publate_bound_vars:FxIndexMap<OwnerId,FxIndexMap<ItemLocalId,Vec<ty::BoundVariableKind>>>,
+publate_bound_vars:SortedMap<ItemLocalId,Vec<ty::BoundVariableKind>>,
 }

compiler/rustc_middle/src/query/mod.rs

@@ -16,6 +16,7 @@ use rustc_ast::expand::StrippedCfgItem;
 use rustc_ast::expand::allocator::AllocatorKind;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::{FxIndexMap,FxIndexSet};
+use rustc_data_structures::sorted_map::SortedMap;
 use rustc_data_structures::steal::Steal;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::Lrc;
@@ -1742,8 +1743,7 @@ rustc_queries! {
  arena_cache
  desc { |tcx| "resolving lifetimes for `{}`", tcx.def_path_str(owner_id)}
 }
- query named_variable_map(owner_id: hir::OwnerId) ->
-Option<&'tcx FxIndexMap<ItemLocalId,ResolvedArg>> {
+ query named_variable_map(owner_id: hir::OwnerId) -> &'tcx SortedMap<ItemLocalId,ResolvedArg> {
  desc { |tcx| "looking up a named region inside `{}`", tcx.def_path_str(owner_id)}
 }
  query is_late_bound_map(owner_id: hir::OwnerId) -> Option<&'tcx FxIndexSet<ItemLocalId>> {
@@ -1759,7 +1759,7 @@ rustc_queries! {
  separate_provide_extern
 }
  query late_bound_vars_map(owner_id: hir::OwnerId)
- -> Option<&'tcx FxIndexMap<ItemLocalId,Vec<ty::BoundVariableKind>>> {
+ -> &'tcx SortedMap<ItemLocalId,Vec<ty::BoundVariableKind>> {
  desc { |tcx| "looking up late bound vars inside `{}`", tcx.def_path_str(owner_id)}
 }
 

compiler/rustc_middle/src/ty/context.rs

@@ -2996,7 +2996,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
 pubfnnamed_bound_var(self,id:HirId) -> Option<resolve_bound_vars::ResolvedArg>{
 debug!(?id,"named_region");
-self.named_variable_map(id.owner).and_then(|map| map.get(&id.local_id).cloned())
+self.named_variable_map(id.owner).get(&id.local_id).cloned()
 }
 
 pubfnis_late_bound(self,id:HirId) -> bool{
@@ -3005,12 +3005,9 @@ impl<'tcx> TyCtxt<'tcx> {
 
 pubfnlate_bound_vars(self,id:HirId) -> &'tcxList<ty::BoundVariableKind>{
 self.mk_bound_variable_kinds(
-&self
-.late_bound_vars_map(id.owner)
-.and_then(|map| map.get(&id.local_id).cloned())
-.unwrap_or_else(|| {
-bug!("No bound vars found for {}",self.hir().node_to_string(id))
-}),
+&self.late_bound_vars_map(id.owner).get(&id.local_id).cloned().unwrap_or_else(|| {
+bug!("No bound vars found for {}",self.hir().node_to_string(id))
+}),
 )
 }