Rollup merge of rust-lang#139772 - nnethercote:rm-hir-Map, r=Zalathar

Remove `hir::Map`

A follow-up to rust-lang#139232.

r? `@Zalathar`

Author: Zalathar

Diff for: compiler/rustc_hir/src/intravisit.rs

@@ -6,7 +6,7 @@
 //! 1. **Shallow visit**: Get a simple callback for every item (or item-like thing) in the HIR.
 //!    - Example: find all items with a `#[foo]` attribute on them.
 //!    - How: Use the `hir_crate_items` or `hir_module_items` query to traverse over item-like ids
-//!       (ItemId, TraitItemId, etc.) and use tcx.def_kind and `tcx.hir().item*(id)` to filter and
+//!       (ItemId, TraitItemId, etc.) and use tcx.def_kind and `tcx.hir_item*(id)` to filter and
 //!       access actual item-like thing, respectively.
 //!    - Pro: Efficient; just walks the lists of item ids and gives users control whether to access
 //!       the hir_owners themselves or not.

Diff for: compiler/rustc_middle/src/hir/map.rs

@@ -1,3 +1,7 @@
+//! This module used to contain a type called `Map`. That type has since been
+//! eliminated, and all its methods are now on `TyCtxt`. But the module name
+//! stays as `map` because there isn't an obviously better name for it.
+
 use rustc_abi::ExternAbi;
 use rustc_ast::visit::{VisitorResult, walk_list};
 use rustc_data_structures::fingerprint::Fingerprint;
@@ -18,16 +22,6 @@ use crate::middle::debugger_visualizer::DebuggerVisualizerFile;
 use crate::query::LocalCrate;
 use crate::ty::TyCtxt;
 
-// FIXME: the structure was necessary in the past but now it
-// only serves as "namespace" for HIR-related methods, and can be
-// removed if all the methods are reasonably renamed and moved to tcx
-// (https://github.com/rust-lang/rust/pull/118256#issuecomment-1826442834).
-#[allow(unused)] // FIXME: temporary
-#[derive(Copy, Clone)]
-pub struct Map<'hir> {
-    pub(super) tcx: TyCtxt<'hir>,
-}
-
 /// An iterator that walks up the ancestor tree of a given `HirId`.
 /// Constructed using `tcx.hir_parent_iter(hir_id)`.
 struct ParentHirIterator<'tcx> {
@@ -335,7 +329,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Returns an iterator of the `DefId`s for all body-owners in this
     /// crate. If you would prefer to iterate over the bodies
-    /// themselves, you can do `self.hir().krate().body_ids.iter()`.
+    /// themselves, you can do `self.hir_crate(()).body_ids.iter()`.
     #[inline]
     pub fn hir_body_owners(self) -> impl Iterator<Item = LocalDefId> {
         self.hir_crate_items(()).body_owners.iter().copied()

Diff for: compiler/rustc_middle/src/hir/mod.rs

@@ -116,11 +116,6 @@ impl ModuleItems {
 }
 
 impl<'tcx> TyCtxt<'tcx> {
-    #[inline(always)]
-    pub fn hir(self) -> map::Map<'tcx> {
-        map::Map { tcx: self }
-    }
-
     pub fn parent_module(self, id: HirId) -> LocalModDefId {
         if !id.is_owner() && self.def_kind(id.owner) == DefKind::Mod {
             LocalModDefId::new_unchecked(id.owner.def_id)

Diff for: compiler/rustc_middle/src/query/mod.rs

@@ -161,11 +161,11 @@ rustc_queries! {
 
     /// Represents crate as a whole (as distinct from the top-level crate module).
     ///
-    /// If you call `hir_crate` (e.g., indirectly by calling `tcx.hir_crate()`),
-    /// we will have to assume that any change means that you need to be recompiled.
-    /// This is because the `hir_crate` query gives you access to all other items.
-    /// To avoid this fate, do not call `tcx.hir_crate()`; instead,
-    /// prefer wrappers like [`TyCtxt::hir_visit_all_item_likes_in_crate`].
+    /// If you call `tcx.hir_crate(())` we will have to assume that any change
+    /// means that you need to be recompiled. This is because the `hir_crate`
+    /// query gives you access to all other items. To avoid this fate, do not
+    /// call `tcx.hir_crate(())`; instead, prefer wrappers like
+    /// [`TyCtxt::hir_visit_all_item_likes_in_crate`].
     query hir_crate(key: ()) -> &'tcx Crate<'tcx> {
         arena_cache
         eval_always
@@ -197,15 +197,15 @@ rustc_queries! {
 
     /// Gives access to the HIR node's parent for the HIR owner `key`.
     ///
-    /// This can be conveniently accessed by methods on `tcx.hir()`.
+    /// This can be conveniently accessed by `tcx.hir_*` methods.
     /// Avoid calling this query directly.
     query hir_owner_parent(key: hir::OwnerId) -> hir::HirId {
         desc { |tcx| "getting HIR parent of `{}`", tcx.def_path_str(key) }
     }
 
     /// Gives access to the HIR nodes and bodies inside `key` if it's a HIR owner.
     ///
-    /// This can be conveniently accessed by methods on `tcx.hir()`.
+    /// This can be conveniently accessed by `tcx.hir_*` methods.
     /// 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) }
@@ -214,7 +214,7 @@ rustc_queries! {
 
     /// Gives access to the HIR attributes inside the HIR owner `key`.
     ///
-    /// This can be conveniently accessed by methods on `tcx.hir()`.
+    /// This can be conveniently accessed by `tcx.hir_*` methods.
     /// Avoid calling this query directly.
     query hir_attr_map(key: hir::OwnerId) -> &'tcx hir::AttributeMap<'tcx> {
         desc { |tcx| "getting HIR owner attributes in `{}`", tcx.def_path_str(key) }

Diff for: compiler/rustc_middle/src/ty/context.rs

@@ -2147,7 +2147,7 @@ impl<'tcx> TyCtxt<'tcx> {
             return vec![];
         };
 
-        let mut v = TraitObjectVisitor(vec![], self.hir());
+        let mut v = TraitObjectVisitor(vec![]);
         v.visit_ty_unambig(hir_output);
         v.0
     }
@@ -2160,7 +2160,7 @@ impl<'tcx> TyCtxt<'tcx> {
         scope_def_id: LocalDefId,
     ) -> Option<(Vec<&'tcx hir::Ty<'tcx>>, Span, Option<Span>)> {
         let hir_id = self.local_def_id_to_hir_id(scope_def_id);
-        let mut v = TraitObjectVisitor(vec![], self.hir());
+        let mut v = TraitObjectVisitor(vec![]);
         // when the return type is a type alias
         if let Some(hir::FnDecl { output: hir::FnRetTy::Return(hir_output), .. }) = self.hir_fn_decl_by_hir_id(hir_id)
             && let hir::TyKind::Path(hir::QPath::Resolved(

Diff for: compiler/rustc_middle/src/ty/diagnostics.rs

@@ -571,7 +571,7 @@ pub fn suggest_constraining_type_params<'a>(
 }
 
 /// Collect al types that have an implicit `'static` obligation that we could suggest `'_` for.
-pub struct TraitObjectVisitor<'tcx>(pub Vec<&'tcx hir::Ty<'tcx>>, pub crate::hir::map::Map<'tcx>);
+pub(crate) struct TraitObjectVisitor<'tcx>(pub(crate) Vec<&'tcx hir::Ty<'tcx>>);
 
 impl<'v> hir::intravisit::Visitor<'v> for TraitObjectVisitor<'v> {
     fn visit_ty(&mut self, ty: &'v hir::Ty<'v, AmbigArg>) {
@@ -592,18 +592,6 @@ impl<'v> hir::intravisit::Visitor<'v> for TraitObjectVisitor<'v> {
     }
 }
 
-/// Collect al types that have an implicit `'static` obligation that we could suggest `'_` for.
-pub struct StaticLifetimeVisitor<'tcx>(pub Vec<Span>, pub crate::hir::map::Map<'tcx>);
-
-impl<'v> hir::intravisit::Visitor<'v> for StaticLifetimeVisitor<'v> {
-    fn visit_lifetime(&mut self, lt: &'v hir::Lifetime) {
-        if let hir::LifetimeName::ImplicitObjectLifetimeDefault | hir::LifetimeName::Static = lt.res
-        {
-            self.0.push(lt.ident.span);
-        }
-    }
-}
-
 pub struct IsSuggestableVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
     infer_suggestable: bool,

Diff for: src/doc/rustc-dev-guide/src/appendix/glossary.md

@@ -31,7 +31,6 @@ Term                                                  | Meaning
 <span id="generics">generics</span>            |  The list of generic parameters defined on an item. There are three kinds of generic parameters: Type, lifetime and const parameters.
 <span id="hir">HIR</span>                      |  The _high-level [IR](#ir)_, created by lowering and desugaring the AST. ([see more](../hir.md))
 <span id="hir-id">`HirId`</span>               |  Identifies a particular node in the HIR by combining a def-id with an "intra-definition offset". See [the HIR chapter for more](../hir.md#identifiers-in-the-hir).
-<span id="hir-map">HIR map</span>              |  The HIR map, accessible via `tcx.hir()`, allows you to quickly navigate the HIR and convert between various forms of identifiers.
 <span id="ice">ICE</span>                      |  Short for _internal compiler error_, this is when the compiler crashes.
 <span id="ich">ICH</span>                      |  Short for _incremental compilation hash_, these are used as fingerprints for things such as HIR and crate metadata, to check if changes have been made. This is useful in incremental compilation to see if part of a crate has changed and should be recompiled.
 <span id="infcx">`infcx`</span>                |  The type inference context (`InferCtxt`). (see `rustc_middle::infer`)

Diff for: src/doc/rustc-dev-guide/src/hir.md

@@ -100,7 +100,7 @@ The HIR uses a bunch of different identifiers that coexist and serve different p
   a wrapper around a [`HirId`]. For more info about HIR bodies, please refer to the
   [HIR chapter][hir-bodies].
 
-These identifiers can be converted into one another through the [HIR map][map].
+These identifiers can be converted into one another through the `TyCtxt`.
 
 [`DefId`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/def_id/struct.DefId.html
 [`LocalDefId`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/def_id/struct.LocalDefId.html
@@ -110,30 +110,24 @@ These identifiers can be converted into one another through the [HIR map][map].
 [`CrateNum`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/def_id/struct.CrateNum.html
 [`DefIndex`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/def_id/struct.DefIndex.html
 [`Body`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir/struct.Body.html
-[hir-map]: ./hir.md#the-hir-map
 [hir-bodies]: ./hir.md#hir-bodies
-[map]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html
 
-## The HIR Map
+## HIR Operations
 
 Most of the time when you are working with the HIR, you will do so via
-the **HIR Map**, accessible in the tcx via [`tcx.hir()`] (and defined in
-the [`hir::map`] module). The [HIR map] contains a [number of methods] to
-convert between IDs of various kinds and to lookup data associated
-with a HIR node.
+`TyCtxt`. It contains a number of methods, defined in the `hir::map` module and
+mostly prefixed with `hir_`, to convert between IDs of various kinds and to
+lookup data associated with a HIR node.
 
-[`tcx.hir()`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.hir
-[`hir::map`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/index.html
-[HIR map]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html
-[number of methods]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html#methods
+[`TyCtxt`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html
 
 For example, if you have a [`LocalDefId`], and you would like to convert it
-to a [`HirId`], you can use [`tcx.hir().local_def_id_to_hir_id(def_id)`][local_def_id_to_hir_id].
+to a [`HirId`], you can use [`tcx.local_def_id_to_hir_id(def_id)`][local_def_id_to_hir_id].
 You need a `LocalDefId`, rather than a `DefId`, since only local items have HIR nodes.
 
-[local_def_id_to_hir_id]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html#method.local_def_id_to_hir_id
+[local_def_id_to_hir_id]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.local_def_id_to_hir_id
 
-Similarly, you can use [`tcx.hir().find(n)`][find] to lookup the node for a
+Similarly, you can use [`tcx.hir_node(n)`][hir_node] to lookup the node for a
 [`HirId`]. This returns a `Option<Node<'hir>>`, where [`Node`] is an enum
 defined in the map. By matching on this, you can find out what sort of
 node the `HirId` referred to and also get a pointer to the data
@@ -142,26 +136,27 @@ that `n` must be some HIR expression, you can do
 [`tcx.hir_expect_expr(n)`][expect_expr], which will extract and return the
 [`&hir::Expr`][Expr], panicking if `n` is not in fact an expression.
 
-[find]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html#method.find
+[hir_node]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.hir_node
 [`Node`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir/enum.Node.html
 [expect_expr]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.expect_expr
 [Expr]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir/struct.Expr.html
 
-Finally, you can use the HIR map to find the parents of nodes, via
-calls like [`tcx.hir().get_parent(n)`][get_parent].
+Finally, you can find the parents of nodes, via
+calls like [`tcx.parent_hir_node(n)`][parent_hir_node].
+
+[get_parent_item]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.parent_hir_node
 
-[get_parent]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html#method.get_parent
 
 ## HIR Bodies
 
 A [`rustc_hir::Body`] represents some kind of executable code, such as the body
 of a function/closure or the definition of a constant. Bodies are
 associated with an **owner**, which is typically some kind of item
 (e.g. an `fn()` or `const`), but could also be a closure expression
-(e.g. `|x, y| x + y`). You can use the HIR map to find the body
-associated with a given def-id ([`maybe_body_owned_by`]) or to find
-the owner of a body ([`body_owner_def_id`]).
+(e.g. `|x, y| x + y`). You can use the `TyCtxt` to find the body
+associated with a given def-id ([`hir_maybe_body_owned_by`]) or to find
+the owner of a body ([`hir_body_owner_def_id`]).
 
 [`rustc_hir::Body`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir/struct.Body.html
-[`maybe_body_owned_by`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html#method.maybe_body_owned_by
-[`body_owner_def_id`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html#method.body_owner_def_id
+[`hir_maybe_body_owned_by`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.hir_maybe_body_owned_by
+[`hir_body_owner_def_id`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TyCtxt.html#method.hir_body_owner_def_id