Auto merge of #120943 - petrochenkov:somehir3, r=oli-obk

Create some minimal HIR for associated opaque types

`LocalDefId`s for opaque types in traits and impls are created after AST -> HIR lowering, so they don't have corresponding HIR and return their various properties through fed queries.

In this PR I also feed some core HIR-related queries for these `LocalDefId`s (which happen to be HIR owners).
As a result all `LocalDefId`s now have corresponding `HirId`s and HIR nodes, and "optional" methods like `opt_local_def_id_to_hir_id` and `opt_hir_node_by_def_id` can be removed.

Follow up to #120206.

compiler/rustc_ast_lowering/src/index.rs

@@ -55,6 +55,7 @@ pub(super) fn index_hir<'hir>(
         OwnerNode::TraitItem(item) => collector.visit_trait_item(item),
         OwnerNode::ImplItem(item) => collector.visit_impl_item(item),
         OwnerNode::ForeignItem(item) => collector.visit_foreign_item(item),
+        OwnerNode::AssocOpaqueTy(..) => unreachable!(),
     };
 
     for (local_id, node) in collector.nodes.iter_enumerated() {

compiler/rustc_hir/src/hir.rs

@@ -2553,6 +2553,11 @@ pub struct OpaqueTy<'hir> {
     pub in_trait: bool,
 }
 
+#[derive(Copy, Clone, Debug, HashStable_Generic)]
+pub struct AssocOpaqueTy {
+    // Add some data if necessary
+}
+
 /// From whence the opaque type came.
 #[derive(Copy, Clone, PartialEq, Eq, Debug, HashStable_Generic)]
 pub enum OpaqueTyOrigin {
@@ -3363,6 +3368,7 @@ pub enum OwnerNode<'hir> {
     TraitItem(&'hir TraitItem<'hir>),
     ImplItem(&'hir ImplItem<'hir>),
     Crate(&'hir Mod<'hir>),
+    AssocOpaqueTy(&'hir AssocOpaqueTy),
 }
 
 impl<'hir> OwnerNode<'hir> {
@@ -3372,7 +3378,7 @@ impl<'hir> OwnerNode<'hir> {
             | OwnerNode::ForeignItem(ForeignItem { ident, .. })
             | OwnerNode::ImplItem(ImplItem { ident, .. })
             | OwnerNode::TraitItem(TraitItem { ident, .. }) => Some(*ident),
-            OwnerNode::Crate(..) => None,
+            OwnerNode::Crate(..) | OwnerNode::AssocOpaqueTy(..) => None,
         }
     }
 
@@ -3385,6 +3391,7 @@ impl<'hir> OwnerNode<'hir> {
             | OwnerNode::ImplItem(ImplItem { span, .. })
             | OwnerNode::TraitItem(TraitItem { span, .. }) => span,
             OwnerNode::Crate(Mod { spans: ModSpans { inner_span, .. }, .. }) => inner_span,
+            OwnerNode::AssocOpaqueTy(..) => unreachable!(),
         }
     }
 
@@ -3443,6 +3450,7 @@ impl<'hir> OwnerNode<'hir> {
             | OwnerNode::ImplItem(ImplItem { owner_id, .. })
             | OwnerNode::ForeignItem(ForeignItem { owner_id, .. }) => *owner_id,
             OwnerNode::Crate(..) => crate::CRATE_HIR_ID.owner,
+            OwnerNode::AssocOpaqueTy(..) => unreachable!(),
         }
     }
 
@@ -3486,6 +3494,7 @@ impl<'hir> Into<Node<'hir>> for OwnerNode<'hir> {
             OwnerNode::ImplItem(n) => Node::ImplItem(n),
             OwnerNode::TraitItem(n) => Node::TraitItem(n),
             OwnerNode::Crate(n) => Node::Crate(n),
+            OwnerNode::AssocOpaqueTy(n) => Node::AssocOpaqueTy(n),
         }
     }
 }
@@ -3523,6 +3532,7 @@ pub enum Node<'hir> {
     WhereBoundPredicate(&'hir WhereBoundPredicate<'hir>),
     // FIXME: Merge into `Node::Infer`.
     ArrayLenInfer(&'hir InferArg),
+    AssocOpaqueTy(&'hir AssocOpaqueTy),
     // Span by reference to minimize `Node`'s size
     #[allow(rustc::pass_by_value)]
     Err(&'hir Span),
@@ -3573,6 +3583,7 @@ impl<'hir> Node<'hir> {
             | Node::Infer(..)
             | Node::WhereBoundPredicate(..)
             | Node::ArrayLenInfer(..)
+            | Node::AssocOpaqueTy(..)
             | Node::Err(..) => None,
         }
     }
@@ -3678,6 +3689,7 @@ impl<'hir> Node<'hir> {
             Node::TraitItem(i) => Some(OwnerNode::TraitItem(i)),
             Node::ImplItem(i) => Some(OwnerNode::ImplItem(i)),
             Node::Crate(i) => Some(OwnerNode::Crate(i)),
+            Node::AssocOpaqueTy(i) => Some(OwnerNode::AssocOpaqueTy(i)),
             _ => None,
         }
     }

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -196,6 +196,7 @@ fn check_well_formed(tcx: TyCtxt<'_>, def_id: hir::OwnerId) -> Result<(), ErrorG
         hir::OwnerNode::TraitItem(item) => check_trait_item(tcx, item),
         hir::OwnerNode::ImplItem(item) => check_impl_item(tcx, item),
         hir::OwnerNode::ForeignItem(item) => check_foreign_item(tcx, item),
+        hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
     };
 
     if let Some(generics) = node.generics() {

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -262,6 +262,7 @@ fn resolve_bound_vars(tcx: TyCtxt<'_>, local_def_id: hir::OwnerId) -> ResolveBou
             visitor.visit_impl_item(item)
         }
         hir::OwnerNode::Crate(_) => {}
+        hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
     }
 
     let mut rl = ResolveBoundVars::default();

compiler/rustc_hir_pretty/src/lib.rs

@@ -121,6 +121,7 @@ impl<'a> State<'a> {
                 self.print_bounds(":", pred.bounds);
             }
             Node::ArrayLenInfer(_) => self.word("_"),
+            Node::AssocOpaqueTy(..) => unreachable!(),
             Node::Err(_) => self.word("/*ERROR*/"),
         }
     }

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -2174,7 +2174,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let mut call_finder = FindClosureArg { tcx: self.tcx, calls: vec![] };
                 let node = self
                     .tcx
-                    .opt_local_def_id_to_hir_id(self.tcx.hir().get_parent_item(call_expr.hir_id))
+                    .opt_local_def_id_to_hir_id(
+                        self.tcx.hir().get_parent_item(call_expr.hir_id).def_id,
+                    )
                     .map(|hir_id| self.tcx.hir_node(hir_id));
                 match node {
                     Some(hir::Node::Item(item)) => call_finder.visit_item(item),

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -2554,6 +2554,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             hir::OwnerNode::ImplItem(i) => visitor.visit_impl_item(i),
             hir::OwnerNode::TraitItem(i) => visitor.visit_trait_item(i),
             hir::OwnerNode::Crate(_) => bug!("OwnerNode::Crate doesn't not have generics"),
+            hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
         }
 
         let ast_generics = self.tcx.hir().get_generics(lifetime_scope).unwrap();

compiler/rustc_lint/src/late.rs

@@ -356,7 +356,7 @@ pub fn late_lint_mod<'tcx, T: LateLintPass<'tcx> + 'tcx>(
         cached_typeck_results: Cell::new(None),
         param_env: ty::ParamEnv::empty(),
         effective_visibilities: tcx.effective_visibilities(()),
-        last_node_with_lint_attrs: tcx.local_def_id_to_hir_id(module_def_id.into()),
+        last_node_with_lint_attrs: tcx.local_def_id_to_hir_id(module_def_id),
         generics: None,
         only_module: true,
     };

compiler/rustc_lint/src/levels.rs

@@ -191,6 +191,7 @@ fn shallow_lint_levels_on(tcx: TyCtxt<'_>, owner: hir::OwnerId) -> ShallowLintLe
                 levels.add_id(hir::CRATE_HIR_ID);
                 levels.visit_mod(mod_, mod_.spans.inner_span, hir::CRATE_HIR_ID)
             }
+            hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
         },
     }
 

compiler/rustc_middle/src/arena.rs

@@ -115,6 +115,7 @@ macro_rules! arena_types {
             [] features: rustc_feature::Features,
             [decode] specialization_graph: rustc_middle::traits::specialization_graph::Graph,
             [] crate_inherent_impls: rustc_middle::ty::CrateInherentImpls,
+            [] hir_owner_nodes: rustc_hir::OwnerNodes<'tcx>,
         ]);
     )
 }

compiler/rustc_middle/src/hir/map/mod.rs

@@ -161,20 +161,18 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Retrieves the `hir::Node` corresponding to `id`, returning `None` if cannot be found.
     #[inline]
     pub fn opt_hir_node_by_def_id(self, id: LocalDefId) -> Option<Node<'tcx>> {
-        Some(self.hir_node(self.opt_local_def_id_to_hir_id(id)?))
+        Some(self.hir_node_by_def_id(id))
     }
 
     /// Retrieves the `hir::Node` corresponding to `id`.
     pub fn hir_node(self, id: HirId) -> Node<'tcx> {
         self.hir_owner_nodes(id.owner).nodes[id.local_id].node
     }
 
-    /// Retrieves the `hir::Node` corresponding to `id`, panicking if it cannot be found.
+    /// Retrieves the `hir::Node` corresponding to `id`.
     #[inline]
-    #[track_caller]
     pub fn hir_node_by_def_id(self, id: LocalDefId) -> Node<'tcx> {
-        self.opt_hir_node_by_def_id(id)
-            .unwrap_or_else(|| bug!("couldn't find HIR node for def id {id:?}"))
+        self.hir_node(self.local_def_id_to_hir_id(id))
     }
 
     /// Returns `HirId` of the parent HIR node of node with this `hir_id`.
@@ -963,6 +961,7 @@ impl<'hir> Map<'hir> {
             Node::Crate(item) => item.spans.inner_span,
             Node::WhereBoundPredicate(pred) => pred.span,
             Node::ArrayLenInfer(inf) => inf.span,
+            Node::AssocOpaqueTy(..) => unreachable!(),
             Node::Err(span) => *span,
         }
     }
@@ -1227,6 +1226,7 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
         Node::Crate(..) => String::from("(root_crate)"),
         Node::WhereBoundPredicate(_) => node_str("where bound predicate"),
         Node::ArrayLenInfer(_) => node_str("array len infer"),
+        Node::AssocOpaqueTy(..) => unreachable!(),
         Node::Err(_) => node_str("error"),
     }
 }

compiler/rustc_middle/src/hir/mod.rs

@@ -127,12 +127,10 @@ pub fn provide(providers: &mut Providers) {
     providers.hir_crate_items = map::hir_crate_items;
     providers.crate_hash = map::crate_hash;
     providers.hir_module_items = map::hir_module_items;
-    providers.opt_local_def_id_to_hir_id = |tcx, def_id| {
-        Some(match tcx.hir_crate(()).owners[def_id] {
-            MaybeOwner::Owner(_) => HirId::make_owner(def_id),
-            MaybeOwner::NonOwner(hir_id) => hir_id,
-            MaybeOwner::Phantom => bug!("No HirId for {:?}", def_id),
-        })
+    providers.local_def_id_to_hir_id = |tcx, def_id| match tcx.hir_crate(()).owners[def_id] {
+        MaybeOwner::Owner(_) => HirId::make_owner(def_id),
+        MaybeOwner::NonOwner(hir_id) => hir_id,
+        MaybeOwner::Phantom => bug!("No HirId for {:?}", def_id),
     };
     providers.opt_hir_owner_nodes =
         |tcx, id| tcx.hir_crate(()).owners.get(id)?.as_owner().map(|i| &i.nodes);

compiler/rustc_middle/src/query/mod.rs

@@ -174,10 +174,8 @@ rustc_queries! {
         cache_on_disk_if { true }
     }
 
-    /// Gives access to the HIR ID for the given `LocalDefId` owner `key` if any.
-    ///
-    /// Definitions that were generated with no HIR, would be fed to return `None`.
-    query opt_local_def_id_to_hir_id(key: LocalDefId) -> Option<hir::HirId>{
+    /// Returns HIR ID for the given `LocalDefId`.
+    query local_def_id_to_hir_id(key: LocalDefId) -> hir::HirId {
         desc { |tcx| "getting HIR ID of `{}`", tcx.def_path_str(key) }
         feedable
     }
@@ -196,6 +194,7 @@ rustc_queries! {
     /// Avoid calling this query directly.
     query opt_hir_owner_nodes(key: LocalDefId) -> Option<&'tcx hir::OwnerNodes<'tcx>> {
         desc { |tcx| "getting HIR owner items in `{}`", tcx.def_path_str(key) }
+        feedable
     }
 
     /// Gives access to the HIR attributes inside the HIR owner `key`.
@@ -204,6 +203,7 @@ rustc_queries! {
     /// Avoid calling this query directly.
     query hir_attrs(key: hir::OwnerId) -> &'tcx hir::AttributeMap<'tcx> {
         desc { |tcx| "getting HIR owner attributes in `{}`", tcx.def_path_str(key) }
+        feedable
     }
 
     /// Given the def_id of a const-generic parameter, computes the associated default const

compiler/rustc_middle/src/ty/context.rs

@@ -589,6 +589,11 @@ impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> {
     pub fn def_id(&self) -> LocalDefId {
         self.key
     }
+
+    // Caller must ensure that `self.key` ID is indeed an owner.
+    pub fn feed_owner_id(&self) -> TyCtxtFeed<'tcx, hir::OwnerId> {
+        TyCtxtFeed { tcx: self.tcx, key: hir::OwnerId { def_id: self.key } }
+    }
 }
 
 /// The central data structure of the compiler. It stores references
@@ -2350,8 +2355,8 @@ impl<'tcx> TyCtxt<'tcx> {
         self.intrinsic_raw(def_id)
     }
 
-    pub fn local_def_id_to_hir_id(self, local_def_id: LocalDefId) -> HirId {
-        self.opt_local_def_id_to_hir_id(local_def_id).unwrap()
+    pub fn opt_local_def_id_to_hir_id(self, local_def_id: LocalDefId) -> Option<HirId> {
+        Some(self.local_def_id_to_hir_id(local_def_id))
     }
 
     pub fn next_trait_solver_globally(self) -> bool {

compiler/rustc_passes/src/reachable.rs

@@ -270,7 +270,8 @@ impl<'tcx> ReachableContext<'tcx> {
             | Node::Ctor(..)
             | Node::Field(_)
             | Node::Ty(_)
-            | Node::Crate(_) => {}
+            | Node::Crate(_)
+            | Node::AssocOpaqueTy(..) => {}
             _ => {
                 bug!(
                     "found unexpected node kind in worklist: {} ({:?})",

compiler/rustc_ty_utils/src/assoc.rs

@@ -1,10 +1,11 @@
 use rustc_data_structures::fx::FxIndexSet;
-use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, DefIdMap, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
+use rustc_hir::{self as hir, HirId};
+use rustc_index::IndexVec;
 use rustc_middle::query::Providers;
-use rustc_middle::ty::{self, ImplTraitInTraitData, TyCtxt};
+use rustc_middle::ty::{self, ImplTraitInTraitData, TyCtxt, TyCtxtFeed};
 use rustc_span::symbol::kw;
 
 pub(crate) fn provide(providers: &mut Providers) {
@@ -237,6 +238,22 @@ fn associated_types_for_impl_traits_in_associated_fn(
     }
 }
 
+fn feed_hir(feed: &TyCtxtFeed<'_, LocalDefId>) {
+    feed.local_def_id_to_hir_id(HirId::make_owner(feed.def_id()));
+    feed.opt_hir_owner_nodes(Some(feed.tcx.arena.alloc(hir::OwnerNodes {
+        opt_hash_including_bodies: None,
+        nodes: IndexVec::from_elem_n(
+            hir::ParentedNode {
+                parent: hir::ItemLocalId::INVALID,
+                node: hir::Node::AssocOpaqueTy(&hir::AssocOpaqueTy {}),
+            },
+            1,
+        ),
+        bodies: Default::default(),
+    })));
+    feed.feed_owner_id().hir_attrs(hir::AttributeMap::EMPTY);
+}
+
 /// Given an `opaque_ty_def_id` corresponding to an `impl Trait` in an associated
 /// function from a trait, synthesize an associated type for that `impl Trait`
 /// that inherits properties that we infer from the method and the opaque type.
@@ -258,9 +275,7 @@ fn associated_type_for_impl_trait_in_trait(
     let local_def_id = trait_assoc_ty.def_id();
     let def_id = local_def_id.to_def_id();
 
-    // There's no HIR associated with this new synthesized `def_id`, so feed
-    // `opt_local_def_id_to_hir_id` with `None`.
-    trait_assoc_ty.opt_local_def_id_to_hir_id(None);
+    feed_hir(&trait_assoc_ty);
 
     // Copy span of the opaque.
     trait_assoc_ty.def_ident_span(Some(span));
@@ -318,9 +333,7 @@ fn associated_type_for_impl_trait_in_impl(
     let local_def_id = impl_assoc_ty.def_id();
     let def_id = local_def_id.to_def_id();
 
-    // There's no HIR associated with this new synthesized `def_id`, so feed
-    // `opt_local_def_id_to_hir_id` with `None`.
-    impl_assoc_ty.opt_local_def_id_to_hir_id(None);
+    feed_hir(&impl_assoc_ty);
 
     // Copy span of the opaque.
     impl_assoc_ty.def_ident_span(Some(span));