Remove hir::AssocItemKind.

Author: cjgillot

compiler/rustc_ast_lowering/src/delegation.rs

@@ -47,6 +47,7 @@ use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::DefId;
 use rustc_middle::span_bug;
 use rustc_middle::ty::{Asyncness, ResolverAstLowering};
+use rustc_span::symbol::kw;
 use rustc_span::{Ident, Span, Symbol};
 use {rustc_ast as ast, rustc_hir as hir};
 
@@ -61,21 +62,6 @@ pub(crate) struct DelegationResults<'hir> {
 }
 
 impl<'hir> LoweringContext<'_, 'hir> {
-    /// Defines whether the delegatee is an associated function whose first parameter is `self`.
-    pub(crate) fn delegatee_is_method(
-        &self,
-        item_id: NodeId,
-        path_id: NodeId,
-        span: Span,
-        is_in_trait_impl: bool,
-    ) -> bool {
-        let sig_id = self.get_delegation_sig_id(item_id, path_id, span, is_in_trait_impl);
-        let Ok(sig_id) = sig_id else {
-            return false;
-        };
-        self.is_method(sig_id, span)
-    }
-
     fn is_method(&self, def_id: DefId, span: Span) -> bool {
         match self.tcx.def_kind(def_id) {
             DefKind::Fn => false,
@@ -101,10 +87,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let sig_id = self.get_delegation_sig_id(item_id, delegation.id, span, is_in_trait_impl);
         match sig_id {
             Ok(sig_id) => {
+                let is_method = self.is_method(sig_id, span);
                 let (param_count, c_variadic) = self.param_count(sig_id);
                 let decl = self.lower_delegation_decl(sig_id, param_count, c_variadic, span);
                 let sig = self.lower_delegation_sig(sig_id, decl, span);
-                let body_id = self.lower_delegation_body(delegation, param_count, span);
+                let body_id = self.lower_delegation_body(delegation, is_method, param_count, span);
                 let ident = self.lower_ident(delegation.ident);
                 let generics = self.lower_delegation_generics(span);
                 DelegationResults { body_id, sig, ident, generics }
@@ -234,10 +221,21 @@ impl<'hir> LoweringContext<'_, 'hir> {
         hir::FnSig { decl, header, span }
     }
 
-    fn generate_param(&mut self, idx: usize, span: Span) -> (hir::Param<'hir>, NodeId) {
+    fn generate_param(
+        &mut self,
+        is_method: bool,
+        idx: usize,
+        span: Span,
+    ) -> (hir::Param<'hir>, NodeId) {
         let pat_node_id = self.next_node_id();
         let pat_id = self.lower_node_id(pat_node_id);
-        let ident = Ident::with_dummy_span(Symbol::intern(&format!("arg{idx}")));
+        // FIXME(cjgillot) AssocItem currently relies on self parameter being exactly named `self`.
+        let name = if is_method && idx == 0 {
+            kw::SelfLower
+        } else {
+            Symbol::intern(&format!("arg{idx}"))
+        };
+        let ident = Ident::with_dummy_span(name);
         let pat = self.arena.alloc(hir::Pat {
             hir_id: pat_id,
             kind: hir::PatKind::Binding(hir::BindingMode::NONE, pat_id, ident, None),
@@ -248,9 +246,21 @@ impl<'hir> LoweringContext<'_, 'hir> {
         (hir::Param { hir_id: self.next_id(), pat, ty_span: span, span }, pat_node_id)
     }
 
-    fn generate_arg(&mut self, idx: usize, param_id: HirId, span: Span) -> hir::Expr<'hir> {
+    fn generate_arg(
+        &mut self,
+        is_method: bool,
+        idx: usize,
+        param_id: HirId,
+        span: Span,
+    ) -> hir::Expr<'hir> {
+        // FIXME(cjgillot) AssocItem currently relies on self parameter being exactly named `self`.
+        let name = if is_method && idx == 0 {
+            kw::SelfLower
+        } else {
+            Symbol::intern(&format!("arg{idx}"))
+        };
         let segments = self.arena.alloc_from_iter(iter::once(hir::PathSegment {
-            ident: Ident::with_dummy_span(Symbol::intern(&format!("arg{idx}"))),
+            ident: Ident::with_dummy_span(name),
             hir_id: self.next_id(),
             res: Res::Local(param_id),
             args: None,
@@ -264,6 +274,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     fn lower_delegation_body(
         &mut self,
         delegation: &Delegation,
+        is_method: bool,
         param_count: usize,
         span: Span,
     ) -> BodyId {
@@ -274,7 +285,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let mut args: Vec<hir::Expr<'_>> = Vec::with_capacity(param_count);
 
             for idx in 0..param_count {
-                let (param, pat_node_id) = this.generate_param(idx, span);
+                let (param, pat_node_id) = this.generate_param(is_method, idx, span);
                 parameters.push(param);
 
                 let arg = if let Some(block) = block
@@ -290,7 +301,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     this.ident_and_label_to_local_id.insert(pat_node_id, param.pat.hir_id.local_id);
                     this.lower_target_expr(&block)
                 } else {
-                    this.generate_arg(idx, param.pat.hir_id, span)
+                    this.generate_arg(is_method, idx, param.pat.hir_id, span)
                 };
                 args.push(arg);
             }

compiler/rustc_ast_lowering/src/index.rs

@@ -384,15 +384,15 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_trait_item_ref(&mut self, ii: &'hir TraitItemRef) {
         // Do not visit the duplicate information in TraitItemRef. We want to
         // map the actual nodes, not the duplicate ones in the *Ref.
-        let TraitItemRef { id, ident: _, kind: _, span: _ } = *ii;
+        let TraitItemRef { id, ident: _, span: _ } = *ii;
 
         self.visit_nested_trait_item(id);
     }
 
     fn visit_impl_item_ref(&mut self, ii: &'hir ImplItemRef) {
         // Do not visit the duplicate information in ImplItemRef. We want to
         // map the actual nodes, not the duplicate ones in the *Ref.
-        let ImplItemRef { id, ident: _, kind: _, span: _, trait_item_def_id: _ } = *ii;
+        let ImplItemRef { id, ident: _, span: _ } = *ii;
 
         self.visit_nested_impl_item(id);
     }

compiler/rustc_ast_lowering/src/item.rs

@@ -392,11 +392,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         (trait_ref, lowered_ty)
                     });
 
-                let new_impl_items = self.arena.alloc_from_iter(
-                    impl_items
-                        .iter()
-                        .map(|item| self.lower_impl_item_ref(item, trait_ref.is_some())),
-                );
+                let new_impl_items = self
+                    .arena
+                    .alloc_from_iter(impl_items.iter().map(|item| self.lower_impl_item_ref(item)));
 
                 // `defaultness.has_value()` is never called for an `impl`, always `true` in order
                 // to not cause an assertion failure inside the `lower_defaultness` function.
@@ -972,30 +970,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn lower_trait_item_ref(&mut self, i: &AssocItem) -> hir::TraitItemRef {
-        let (ident, kind) = match &i.kind {
-            AssocItemKind::Const(box ConstItem { ident, .. }) => {
-                (*ident, hir::AssocItemKind::Const)
-            }
-            AssocItemKind::Type(box TyAlias { ident, .. }) => (*ident, hir::AssocItemKind::Type),
-            AssocItemKind::Fn(box Fn { ident, sig, .. }) => {
-                (*ident, hir::AssocItemKind::Fn { has_self: sig.decl.has_self() })
-            }
-            AssocItemKind::Delegation(box delegation) => (
-                delegation.ident,
-                hir::AssocItemKind::Fn {
-                    has_self: self.delegatee_is_method(i.id, delegation.id, i.span, false),
-                },
-            ),
-            AssocItemKind::MacCall(..) | AssocItemKind::DelegationMac(..) => {
-                panic!("macros should have been expanded by now")
-            }
-        };
         let id = hir::TraitItemId { owner_id: self.owner_id(i.id) };
         hir::TraitItemRef {
             id,
-            ident: self.lower_ident(ident),
+            ident: self.lower_ident(i.kind.ident().unwrap()),
             span: self.lower_span(i.span),
-            kind,
         }
     }
 
@@ -1127,40 +1106,22 @@ impl<'hir> LoweringContext<'_, 'hir> {
             span: self.lower_span(i.span),
             defaultness,
             has_delayed_lints: !self.delayed_lints.is_empty(),
+            trait_item_def_id: self
+                .resolver
+                .get_partial_res(i.id)
+                .map(|r| r.expect_full_res().opt_def_id())
+                .unwrap_or(None),
         };
         self.arena.alloc(item)
     }
 
-    fn lower_impl_item_ref(&mut self, i: &AssocItem, is_in_trait_impl: bool) -> hir::ImplItemRef {
+    fn lower_impl_item_ref(&mut self, i: &AssocItem) -> hir::ImplItemRef {
         hir::ImplItemRef {
             id: hir::ImplItemId { owner_id: self.owner_id(i.id) },
             // `unwrap` is safe because `AssocItemKind::{MacCall,DelegationMac}` are the only
             // assoc item kinds without an identifier and they cannot reach here.
             ident: self.lower_ident(i.kind.ident().unwrap()),
             span: self.lower_span(i.span),
-            kind: match &i.kind {
-                AssocItemKind::Const(..) => hir::AssocItemKind::Const,
-                AssocItemKind::Type(..) => hir::AssocItemKind::Type,
-                AssocItemKind::Fn(box Fn { sig, .. }) => {
-                    hir::AssocItemKind::Fn { has_self: sig.decl.has_self() }
-                }
-                AssocItemKind::Delegation(box delegation) => hir::AssocItemKind::Fn {
-                    has_self: self.delegatee_is_method(
-                        i.id,
-                        delegation.id,
-                        i.span,
-                        is_in_trait_impl,
-                    ),
-                },
-                AssocItemKind::MacCall(..) | AssocItemKind::DelegationMac(..) => {
-                    panic!("macros should have been expanded by now")
-                }
-            },
-            trait_item_def_id: self
-                .resolver
-                .get_partial_res(i.id)
-                .map(|r| r.expect_full_res().opt_def_id())
-                .unwrap_or(None),
         }
     }
 

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -681,46 +681,30 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             return (false, false, None);
         }
         let my_def = self.body.source.def_id();
-        let my_hir = self.infcx.tcx.local_def_id_to_hir_id(my_def.as_local().unwrap());
         let Some(td) =
             self.infcx.tcx.impl_of_method(my_def).and_then(|x| self.infcx.tcx.trait_id_of_impl(x))
         else {
             return (false, false, None);
         };
+
+        let implemented_trait_item = self.infcx.tcx.associated_item(my_def).trait_item_def_id;
+
         (
             true,
             td.is_local(),
-            td.as_local().and_then(|tld| match self.infcx.tcx.hir_node_by_def_id(tld) {
-                Node::Item(hir::Item {
-                    kind: hir::ItemKind::Trait(_, _, _, _, _, items), ..
-                }) => {
-                    let mut f_in_trait_opt = None;
-                    for hir::TraitItemRef { id: fi, kind: k, .. } in *items {
-                        let hi = fi.hir_id();
-                        if !matches!(k, hir::AssocItemKind::Fn { .. }) {
-                            continue;
-                        }
-                        if self.infcx.tcx.hir_name(hi) != self.infcx.tcx.hir_name(my_hir) {
-                            continue;
-                        }
-                        f_in_trait_opt = Some(hi);
-                        break;
-                    }
-                    f_in_trait_opt.and_then(|f_in_trait| {
-                        if let Node::TraitItem(ti) = self.infcx.tcx.hir_node(f_in_trait)
-                            && let hir::TraitItemKind::Fn(sig, _) = ti.kind
-                            && let Some(ty) = sig.decl.inputs.get(local.index() - 1)
-                            && let hir::TyKind::Ref(_, mut_ty) = ty.kind
-                            && let hir::Mutability::Not = mut_ty.mutbl
-                            && sig.decl.implicit_self.has_implicit_self()
-                        {
-                            Some(ty.span)
-                        } else {
-                            None
-                        }
-                    })
+            implemented_trait_item.and_then(|f_in_trait| {
+                let f_in_trait = f_in_trait.as_local()?;
+                if let Node::TraitItem(ti) = self.infcx.tcx.hir_node_by_def_id(f_in_trait)
+                    && let hir::TraitItemKind::Fn(sig, _) = ti.kind
+                    && let Some(ty) = sig.decl.inputs.get(local.index() - 1)
+                    && let hir::TyKind::Ref(_, mut_ty) = ty.kind
+                    && let hir::Mutability::Not = mut_ty.mutbl
+                    && sig.decl.implicit_self.has_implicit_self()
+                {
+                    Some(ty.span)
+                } else {
+                    None
                 }
-                _ => None,
             }),
         )
     }

compiler/rustc_hir/src/hir.rs

@@ -3171,6 +3171,8 @@ pub struct ImplItem<'hir> {
     pub span: Span,
     pub vis_span: Span,
     pub has_delayed_lints: bool,
+    /// When we are in a trait impl, link to the trait-item's id.
+    pub trait_item_def_id: Option<DefId>,
 }
 
 impl<'hir> ImplItem<'hir> {
@@ -4433,7 +4435,6 @@ impl ItemKind<'_> {
 pub struct TraitItemRef {
     pub id: TraitItemId,
     pub ident: Ident,
-    pub kind: AssocItemKind,
     pub span: Span,
 }
 
@@ -4447,17 +4448,7 @@ pub struct TraitItemRef {
 pub struct ImplItemRef {
     pub id: ImplItemId,
     pub ident: Ident,
-    pub kind: AssocItemKind,
     pub span: Span,
-    /// When we are in a trait impl, link to the trait-item's id.
-    pub trait_item_def_id: Option<DefId>,
-}
-
-#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
-pub enum AssocItemKind {
-    Const,
-    Fn { has_self: bool },
-    Type,
 }
 
 // The bodies for items are stored "out of line", in a separate
@@ -4985,7 +4976,7 @@ mod size_asserts {
     static_assert_size!(GenericBound<'_>, 64);
     static_assert_size!(Generics<'_>, 56);
     static_assert_size!(Impl<'_>, 80);
-    static_assert_size!(ImplItem<'_>, 88);
+    static_assert_size!(ImplItem<'_>, 96);
     static_assert_size!(ImplItemKind<'_>, 40);
     static_assert_size!(Item<'_>, 88);
     static_assert_size!(ItemKind<'_>, 64);

compiler/rustc_hir/src/intravisit.rs

@@ -499,9 +499,6 @@ pub trait Visitor<'v>: Sized {
     fn visit_attribute(&mut self, _attr: &'v Attribute) -> Self::Result {
         Self::Result::output()
     }
-    fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) -> Self::Result {
-        walk_associated_item_kind(self, kind)
-    }
     fn visit_defaultness(&mut self, defaultness: &'v Defaultness) -> Self::Result {
         walk_defaultness(self, defaultness)
     }
@@ -1252,10 +1249,9 @@ pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(
     visitor: &mut V,
     trait_item_ref: &'v TraitItemRef,
 ) -> V::Result {
-    let TraitItemRef { id, ident, ref kind, span: _ } = *trait_item_ref;
+    let TraitItemRef { id, ident, span: _ } = *trait_item_ref;
     try_visit!(visitor.visit_nested_trait_item(id));
-    try_visit!(visitor.visit_ident(ident));
-    visitor.visit_associated_item_kind(kind)
+    visitor.visit_ident(ident)
 }
 
 pub fn walk_impl_item<'v, V: Visitor<'v>>(
@@ -1271,6 +1267,7 @@ pub fn walk_impl_item<'v, V: Visitor<'v>>(
         span: _,
         vis_span: _,
         has_delayed_lints: _,
+        trait_item_def_id: _,
     } = *impl_item;
 
     try_visit!(visitor.visit_ident(ident));
@@ -1306,10 +1303,9 @@ pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(
     visitor: &mut V,
     impl_item_ref: &'v ImplItemRef,
 ) -> V::Result {
-    let ImplItemRef { id, ident, ref kind, span: _, trait_item_def_id: _ } = *impl_item_ref;
+    let ImplItemRef { id, ident, span: _ } = *impl_item_ref;
     try_visit!(visitor.visit_nested_impl_item(id));
-    try_visit!(visitor.visit_ident(ident));
-    visitor.visit_associated_item_kind(kind)
+    visitor.visit_ident(ident)
 }
 
 pub fn walk_trait_ref<'v, V: Visitor<'v>>(
@@ -1483,13 +1479,6 @@ pub fn walk_assoc_item_constraint<'v, V: Visitor<'v>>(
     V::Result::output()
 }
 
-pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) -> V::Result {
-    // No visitable content here: this fn exists so you can call it if
-    // the right thing to do, should content be added in the future,
-    // would be to walk it.
-    V::Result::output()
-}
-
 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) -> V::Result {
     // No visitable content here: this fn exists so you can call it if
     // the right thing to do, should content be added in the future,