Auto merge of #93373 - spastorino:def_id_to_hir_id_refactor, r=oli-obk

Store def_id_to_hir_id as variant in hir_owner.

If hir_owner is Owner(_), the LocalDefId is pointing to an owner, so the ItemLocalId is 0.
If the HIR node does not exist, we store Phantom.
Otherwise, we store the HirId associated to the LocalDefId.

Related to #89278

r? `@oli-obk`

4 files changed, 43 insertions, 26 deletions

diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 1885df6ac5d..649cb34bd5f 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -162,7 +162,7 @@ impl<'hir> Map<'hir> {
 
     pub fn items(&self) -> impl Iterator<Item = &'hir Item<'hir>> + 'hir {
         let krate = self.krate();
-        krate.owners.iter().filter_map(|owner| match owner.as_ref()?.node() {
+        krate.owners.iter().filter_map(|owner| match owner.as_owner()?.node() {
             OwnerNode::Item(item) => Some(item),
             _ => None,
         })
@@ -205,7 +205,8 @@ impl<'hir> Map<'hir> {
             Some(hir_id.owner)
         } else {
             self.tcx
-                .hir_owner_nodes(hir_id.owner)?
+                .hir_owner_nodes(hir_id.owner)
+                .as_owner()?
                 .local_id_to_def_id
                 .get(&hir_id.local_id)
                 .copied()
@@ -214,8 +215,7 @@ impl<'hir> Map<'hir> {
 
     #[inline]
     pub fn local_def_id_to_hir_id(&self, def_id: LocalDefId) -> HirId {
-        // FIXME(#85914) is this access safe for incr. comp.?
-        self.tcx.untracked_resolutions.definitions.local_def_id_to_hir_id(def_id)
+        self.tcx.local_def_id_to_hir_id(def_id)
     }
 
     pub fn iter_local_def_id(&self) -> impl Iterator<Item = LocalDefId> + '_ {
@@ -321,7 +321,7 @@ impl<'hir> Map<'hir> {
         if id.local_id == ItemLocalId::from_u32(0) {
             Some(self.tcx.hir_owner_parent(id.owner))
         } else {
-            let owner = self.tcx.hir_owner_nodes(id.owner)?;
+            let owner = self.tcx.hir_owner_nodes(id.owner).as_owner()?;
             let node = owner.nodes[id.local_id].as_ref()?;
             let hir_id = HirId { owner: id.owner, local_id: node.parent };
             Some(hir_id)
@@ -338,7 +338,7 @@ impl<'hir> Map<'hir> {
             let owner = self.tcx.hir_owner(id.owner)?;
             Some(owner.node.into())
         } else {
-            let owner = self.tcx.hir_owner_nodes(id.owner)?;
+            let owner = self.tcx.hir_owner_nodes(id.owner).as_owner()?;
             let node = owner.nodes[id.local_id].as_ref()?;
             Some(node.node)
         }
@@ -522,7 +522,7 @@ impl<'hir> Map<'hir> {
             .owners
             .iter_enumerated()
             .flat_map(move |(owner, owner_info)| {
-                let bodies = &owner_info.as_ref()?.nodes.bodies;
+                let bodies = &owner_info.as_owner()?.nodes.bodies;
                 Some(bodies.iter().map(move |&(local_id, _)| {
                     let hir_id = HirId { owner, local_id };
                     let body_id = BodyId { hir_id };
@@ -539,7 +539,7 @@ impl<'hir> Map<'hir> {
 
         par_iter(&self.krate().owners.raw).enumerate().for_each(|(owner, owner_info)| {
             let owner = LocalDefId::new(owner);
-            if let Some(owner_info) = owner_info {
+            if let MaybeOwner::Owner(owner_info) = owner_info {
                 par_iter(owner_info.nodes.bodies.range(..)).for_each(|(local_id, _)| {
                     let hir_id = HirId { owner, local_id: *local_id };
                     let body_id = BodyId { hir_id };
@@ -601,7 +601,7 @@ impl<'hir> Map<'hir> {
     pub fn walk_attributes(self, visitor: &mut impl Visitor<'hir>) {
         let krate = self.krate();
         for (owner, info) in krate.owners.iter_enumerated() {
-            if let Some(info) = info {
+            if let MaybeOwner::Owner(info) = info {
                 for (local_id, attrs) in info.attrs.map.iter() {
                     let id = HirId { owner, local_id: *local_id };
                     for a in *attrs {
@@ -625,7 +625,7 @@ impl<'hir> Map<'hir> {
         V: itemlikevisit::ItemLikeVisitor<'hir>,
     {
         let krate = self.krate();
-        for owner in krate.owners.iter().filter_map(Option::as_ref) {
+        for owner in krate.owners.iter().filter_map(|i| i.as_owner()) {
             match owner.node() {
                 OwnerNode::Item(item) => visitor.visit_item(item),
                 OwnerNode::ForeignItem(item) => visitor.visit_foreign_item(item),
@@ -642,12 +642,14 @@ impl<'hir> Map<'hir> {
         V: itemlikevisit::ParItemLikeVisitor<'hir> + Sync + Send,
     {
         let krate = self.krate();
-        par_for_each_in(&krate.owners.raw, |owner| match owner.as_ref().map(OwnerInfo::node) {
-            Some(OwnerNode::Item(item)) => visitor.visit_item(item),
-            Some(OwnerNode::ForeignItem(item)) => visitor.visit_foreign_item(item),
-            Some(OwnerNode::ImplItem(item)) => visitor.visit_impl_item(item),
-            Some(OwnerNode::TraitItem(item)) => visitor.visit_trait_item(item),
-            Some(OwnerNode::Crate(_)) | None => {}
+        par_for_each_in(&krate.owners.raw, |owner| match owner.map(OwnerInfo::node) {
+            MaybeOwner::Owner(OwnerNode::Item(item)) => visitor.visit_item(item),
+            MaybeOwner::Owner(OwnerNode::ForeignItem(item)) => visitor.visit_foreign_item(item),
+            MaybeOwner::Owner(OwnerNode::ImplItem(item)) => visitor.visit_impl_item(item),
+            MaybeOwner::Owner(OwnerNode::TraitItem(item)) => visitor.visit_trait_item(item),
+            MaybeOwner::Owner(OwnerNode::Crate(_))
+            | MaybeOwner::NonOwner(_)
+            | MaybeOwner::Phantom => {}
         })
     }
 
@@ -1121,7 +1123,7 @@ pub(super) fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh {
             .owners
             .iter_enumerated()
             .filter_map(|(def_id, info)| {
-                let _ = info.as_ref()?;
+                let _ = info.as_owner()?;
                 let def_path_hash = definitions.def_path_hash(def_id);
                 let span = definitions.def_span(def_id);
                 debug_assert_eq!(span.parent(), None);
diff --git a/compiler/rustc_middle/src/hir/mod.rs b/compiler/rustc_middle/src/hir/mod.rs
index b4c7bb7eba7..1053f0cefbe 100644
--- a/compiler/rustc_middle/src/hir/mod.rs
+++ b/compiler/rustc_middle/src/hir/mod.rs
@@ -65,20 +65,27 @@ pub fn provide(providers: &mut Providers) {
     providers.crate_hash = map::crate_hash;
     providers.hir_module_items = map::hir_module_items;
     providers.hir_owner = |tcx, id| {
-        let owner = tcx.hir_crate(()).owners.get(id)?.as_ref()?;
+        let owner = tcx.hir_crate(()).owners.get(id)?.as_owner()?;
         let node = owner.node();
         Some(Owner { node, hash_without_bodies: owner.nodes.hash_without_bodies })
     };
-    providers.hir_owner_nodes = |tcx, id| tcx.hir_crate(()).owners[id].as_ref().map(|i| &i.nodes);
+    providers.local_def_id_to_hir_id = |tcx, id| {
+        let owner = tcx.hir_crate(()).owners[id].map(|_| ());
+        match owner {
+            MaybeOwner::Owner(_) => HirId::make_owner(id),
+            MaybeOwner::Phantom => bug!("No HirId for {:?}", id),
+            MaybeOwner::NonOwner(hir_id) => hir_id,
+        }
+    };
+    providers.hir_owner_nodes = |tcx, id| tcx.hir_crate(()).owners[id].map(|i| &i.nodes);
     providers.hir_owner_parent = |tcx, id| {
         // Accessing the def_key is ok since its value is hashed as part of `id`'s DefPathHash.
         let parent = tcx.untracked_resolutions.definitions.def_key(id).parent;
         let parent = parent.map_or(CRATE_HIR_ID, |local_def_index| {
             let def_id = LocalDefId { local_def_index };
-            let mut parent_hir_id =
-                tcx.untracked_resolutions.definitions.local_def_id_to_hir_id(def_id);
+            let mut parent_hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
             if let Some(local_id) =
-                tcx.hir_crate(()).owners[parent_hir_id.owner].as_ref().unwrap().parenting.get(&id)
+                tcx.hir_crate(()).owners[parent_hir_id.owner].unwrap().parenting.get(&id)
             {
                 parent_hir_id.local_id = *local_id;
             }
@@ -87,7 +94,7 @@ pub fn provide(providers: &mut Providers) {
         parent
     };
     providers.hir_attrs =
-        |tcx, id| tcx.hir_crate(()).owners[id].as_ref().map_or(AttributeMap::EMPTY, |o| &o.attrs);
+        |tcx, id| tcx.hir_crate(()).owners[id].as_owner().map_or(AttributeMap::EMPTY, |o| &o.attrs);
     providers.source_span = |tcx, def_id| tcx.resolutions(()).definitions.def_span(def_id);
     providers.def_span = |tcx, def_id| tcx.hir().span_if_local(def_id).unwrap_or(DUMMY_SP);
     providers.fn_arg_names = |tcx, id| {
@@ -111,4 +118,6 @@ pub fn provide(providers: &mut Providers) {
         let id = id.expect_local();
         tcx.resolutions(()).definitions.expansion_that_defined(id)
     };
+    providers.in_scope_traits_map =
+        |tcx, id| tcx.hir_crate(()).owners[id].as_owner().map(|owner_info| &owner_info.trait_map);
 }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 54391bd649e..12ece9e6afb 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -56,6 +56,14 @@ rustc_queries! {
         desc { |tcx| "HIR owner of `{}`", tcx.def_path_str(key.to_def_id()) }
     }
 
+    /// Gives access to the HIR ID for the given `LocalDefId` owner `key`.
+    ///
+    /// This can be conveniently accessed by methods on `tcx.hir()`.
+    /// Avoid calling this query directly.
+    query local_def_id_to_hir_id(key: LocalDefId) -> hir::HirId {
+        desc { |tcx| "HIR ID of `{}`", tcx.def_path_str(key.to_def_id()) }
+    }
+
     /// Gives access to the HIR node's parent for the HIR owner `key`.
     ///
     /// This can be conveniently accessed by methods on `tcx.hir()`.
@@ -68,7 +76,7 @@ rustc_queries! {
     ///
     /// This can be conveniently accessed by methods on `tcx.hir()`.
     /// Avoid calling this query directly.
-    query hir_owner_nodes(key: LocalDefId) -> Option<&'tcx hir::OwnerNodes<'tcx>> {
+    query hir_owner_nodes(key: LocalDefId) -> hir::MaybeOwner<&'tcx hir::OwnerNodes<'tcx>> {
         desc { |tcx| "HIR owner items in `{}`", tcx.def_path_str(key.to_def_id()) }
     }
 
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index d063494f2bc..5dae4b9e4c9 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -2875,8 +2875,6 @@ fn ptr_eq<T, U>(t: *const T, u: *const U) -> bool {
 }
 
 pub fn provide(providers: &mut ty::query::Providers) {
-    providers.in_scope_traits_map =
-        |tcx, id| tcx.hir_crate(()).owners[id].as_ref().map(|owner_info| &owner_info.trait_map);
     providers.resolutions = |tcx, ()| &tcx.untracked_resolutions;
     providers.module_reexports =
         |tcx, id| tcx.resolutions(()).reexport_map.get(&id).map(|v| &v[..]);