Separate AnonConst from ConstBlock in HIR.

compiler/rustc_ast_lowering/src/expr.rs

@@ -71,9 +71,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
             let kind = match &e.kind {
                 ExprKind::Array(exprs) => hir::ExprKind::Array(self.lower_exprs(exprs)),
-                ExprKind::ConstBlock(anon_const) => {
-                    let anon_const = self.lower_anon_const(anon_const);
-                    hir::ExprKind::ConstBlock(anon_const)
+                ExprKind::ConstBlock(c) => {
+                    let c = self.with_new_scopes(|this| hir::ConstBlock {
+                        def_id: this.local_def_id(c.id),
+                        hir_id: this.lower_node_id(c.id),
+                        body: this.lower_const_body(c.value.span, Some(&c.value)),
+                    });
+                    hir::ExprKind::ConstBlock(c)
                 }
                 ExprKind::Repeat(expr, count) => {
                     let expr = self.lower_expr(expr);

compiler/rustc_ast_lowering/src/index.rs

@@ -223,6 +223,14 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
+    fn visit_inline_const(&mut self, constant: &'hir ConstBlock) {
+        self.insert(DUMMY_SP, constant.hir_id, Node::ConstBlock(constant));
+
+        self.with_parent(constant.hir_id, |this| {
+            intravisit::walk_inline_const(this, constant);
+        });
+    }
+
     fn visit_expr(&mut self, expr: &'hir Expr<'hir>) {
         self.insert(expr.span, expr.hir_id, Node::Expr(expr));
 

compiler/rustc_hir/src/hir.rs

@@ -1675,6 +1675,14 @@ pub struct AnonConst {
     pub body: BodyId,
 }
 
+/// An inline constant expression `const { something }`.
+#[derive(Copy, Clone, Debug, HashStable_Generic)]
+pub struct ConstBlock {
+    pub hir_id: HirId,
+    pub def_id: LocalDefId,
+    pub body: BodyId,
+}
+
 /// An expression.
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub struct Expr<'hir> {
@@ -1922,7 +1930,7 @@ pub fn is_range_literal(expr: &Expr<'_>) -> bool {
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub enum ExprKind<'hir> {
     /// Allow anonymous constants from an inline `const` block
-    ConstBlock(AnonConst),
+    ConstBlock(ConstBlock),
     /// An array (e.g., `[a, b, c, d]`).
     Array(&'hir [Expr<'hir>]),
     /// A function call.
@@ -3641,6 +3649,7 @@ pub enum Node<'hir> {
     Variant(&'hir Variant<'hir>),
     Field(&'hir FieldDef<'hir>),
     AnonConst(&'hir AnonConst),
+    ConstBlock(&'hir ConstBlock),
     Expr(&'hir Expr<'hir>),
     ExprField(&'hir ExprField<'hir>),
     Stmt(&'hir Stmt<'hir>),
@@ -3695,6 +3704,7 @@ impl<'hir> Node<'hir> {
             Node::TypeBinding(b) => Some(b.ident),
             Node::Param(..)
             | Node::AnonConst(..)
+            | Node::ConstBlock(..)
             | Node::Expr(..)
             | Node::Stmt(..)
             | Node::Block(..)
@@ -3758,7 +3768,7 @@ impl<'hir> Node<'hir> {
             })
             | Node::Expr(Expr {
                 kind:
-                    ExprKind::ConstBlock(AnonConst { body, .. })
+                    ExprKind::ConstBlock(ConstBlock { body, .. })
                     | ExprKind::Closure(Closure { body, .. })
                     | ExprKind::Repeat(_, ArrayLen::Body(AnonConst { body, .. })),
                 ..
@@ -3878,6 +3888,13 @@ impl<'hir> Node<'hir> {
         this
     }
 
+    /// Expect a [`Node::ConstBlock`] or panic.
+    #[track_caller]
+    pub fn expect_inline_const(self) -> &'hir ConstBlock {
+        let Node::ConstBlock(this) = self else { self.expect_failed("an inline constant") };
+        this
+    }
+
     /// Expect a [`Node::Expr`] or panic.
     #[track_caller]
     pub fn expect_expr(self) -> &'hir Expr<'hir> {

compiler/rustc_hir/src/intravisit.rs

@@ -335,6 +335,9 @@ pub trait Visitor<'v>: Sized {
     fn visit_anon_const(&mut self, c: &'v AnonConst) {
         walk_anon_const(self, c)
     }
+    fn visit_inline_const(&mut self, c: &'v ConstBlock) {
+        walk_inline_const(self, c)
+    }
     fn visit_expr(&mut self, ex: &'v Expr<'v>) {
         walk_expr(self, ex)
     }
@@ -679,13 +682,18 @@ pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonCo
     visitor.visit_nested_body(constant.body);
 }
 
+pub fn walk_inline_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v ConstBlock) {
+    visitor.visit_id(constant.hir_id);
+    visitor.visit_nested_body(constant.body);
+}
+
 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
     visitor.visit_id(expression.hir_id);
     match expression.kind {
         ExprKind::Array(subexpressions) => {
             walk_list!(visitor, visit_expr, subexpressions);
         }
-        ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
+        ExprKind::ConstBlock(ref const_block) => visitor.visit_inline_const(const_block),
         ExprKind::Repeat(ref element, ref count) => {
             visitor.visit_expr(element);
             visitor.visit_array_length(count)

compiler/rustc_hir_analysis/src/check/region.rs

@@ -392,7 +392,7 @@ fn resolve_expr<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, expr: &'tcx h
         // Manually recurse over closures and inline consts, because they are the only
         // case of nested bodies that share the parent environment.
         hir::ExprKind::Closure(&hir::Closure { body, .. })
-        | hir::ExprKind::ConstBlock(hir::AnonConst { body, .. }) => {
+        | hir::ExprKind::ConstBlock(hir::ConstBlock { body, .. }) => {
             let body = visitor.tcx.hir().body(body);
             visitor.visit_body(body);
         }

compiler/rustc_hir_analysis/src/collect/generics_of.rs

@@ -123,9 +123,6 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                     {
                         Some(parent_def_id.to_def_id())
                     }
-                    Node::Expr(&Expr { kind: ExprKind::ConstBlock(_), .. }) => {
-                        Some(tcx.typeck_root_def_id(def_id.to_def_id()))
-                    }
                     // Exclude `GlobalAsm` here which cannot have generics.
                     Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. })
                         if asm.operands.iter().any(|(op, _op_sp)| match op {
@@ -142,7 +139,8 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                 }
             }
         }
-        Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => {
+        Node::ConstBlock(_)
+        | Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => {
             Some(tcx.typeck_root_def_id(def_id.to_def_id()))
         }
         Node::Item(item) => match item.kind {
@@ -339,17 +337,14 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
     }
 
     // provide junk type parameter defs for const blocks.
-    if let Node::AnonConst(_) = node {
-        let parent_node = tcx.hir().get_parent(hir_id);
-        if let Node::Expr(&Expr { kind: ExprKind::ConstBlock(_), .. }) = parent_node {
-            params.push(ty::GenericParamDef {
-                index: next_index(),
-                name: Symbol::intern("<const_ty>"),
-                def_id: def_id.to_def_id(),
-                pure_wrt_drop: false,
-                kind: ty::GenericParamDefKind::Type { has_default: false, synthetic: false },
-            });
-        }
+    if let Node::ConstBlock(_) = node {
+        params.push(ty::GenericParamDef {
+            index: next_index(),
+            name: Symbol::intern("<const_ty>"),
+            def_id: def_id.to_def_id(),
+            pure_wrt_drop: false,
+            kind: ty::GenericParamDefKind::Type { has_default: false, synthetic: false },
+        });
     }
 
     let param_def_id_to_index = params.iter().map(|param| (param.def_id, param.index)).collect();

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -34,12 +34,6 @@ fn anon_const_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
         Node::Ty(&Ty { kind: TyKind::Typeof(ref e), .. }) if e.hir_id == hir_id => {
             return tcx.typeck(def_id).node_type(e.hir_id)
         }
-        Node::Expr(&Expr { kind: ExprKind::ConstBlock(ref anon_const), .. })
-            if anon_const.hir_id == hir_id =>
-        {
-            let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id());
-            return substs.as_inline_const().ty()
-        }
         Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. })
         | Node::Item(&Item { kind: ItemKind::GlobalAsm(asm), .. })
             if asm.operands.iter().any(|(op, _op_sp)| match op {
@@ -487,6 +481,11 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<Ty
 
         Node::AnonConst(_) => anon_const_type_of(tcx, def_id),
 
+        Node::ConstBlock(_) => {
+            let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id());
+            substs.as_inline_const().ty()
+        }
+
         Node::GenericParam(param) => match &param.kind {
             GenericParamKind::Type { default: Some(ty), .. }
             | GenericParamKind::Const { ty, .. } => icx.to_ty(ty),

compiler/rustc_hir_pretty/src/lib.rs

@@ -84,6 +84,7 @@ impl<'a> State<'a> {
             Node::ImplItem(a) => self.print_impl_item(a),
             Node::Variant(a) => self.print_variant(a),
             Node::AnonConst(a) => self.print_anon_const(a),
+            Node::ConstBlock(a) => self.print_inline_const(a),
             Node::Expr(a) => self.print_expr(a),
             Node::ExprField(a) => self.print_expr_field(&a),
             Node::Stmt(a) => self.print_stmt(a),
@@ -1095,10 +1096,10 @@ impl<'a> State<'a> {
         self.end()
     }
 
-    fn print_expr_anon_const(&mut self, anon_const: &hir::AnonConst) {
+    fn print_inline_const(&mut self, constant: &hir::ConstBlock) {
         self.ibox(INDENT_UNIT);
         self.word_space("const");
-        self.print_anon_const(anon_const);
+        self.ann.nested(self, Nested::Body(constant.body));
         self.end()
     }
 
@@ -1370,7 +1371,7 @@ impl<'a> State<'a> {
                 self.print_expr_vec(exprs);
             }
             hir::ExprKind::ConstBlock(ref anon_const) => {
-                self.print_expr_anon_const(anon_const);
+                self.print_inline_const(anon_const);
             }
             hir::ExprKind::Repeat(element, ref count) => {
                 self.print_expr_repeat(element, count);

compiler/rustc_hir_typeck/src/expr.rs

@@ -348,9 +348,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             ExprKind::DropTemps(e) => self.check_expr_with_expectation(e, expected),
             ExprKind::Array(args) => self.check_expr_array(args, expected, expr),
-            ExprKind::ConstBlock(ref anon_const) => {
-                self.check_expr_const_block(anon_const, expected, expr)
-            }
+            ExprKind::ConstBlock(ref block) => self.check_expr_const_block(block, expected, expr),
             ExprKind::Repeat(element, ref count) => {
                 self.check_expr_repeat(element, count, expected, expr)
             }
@@ -1368,20 +1366,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     fn check_expr_const_block(
         &self,
-        anon_const: &'tcx hir::AnonConst,
+        block: &'tcx hir::ConstBlock,
         expected: Expectation<'tcx>,
         _expr: &'tcx hir::Expr<'tcx>,
     ) -> Ty<'tcx> {
-        let body = self.tcx.hir().body(anon_const.body);
+        let body = self.tcx.hir().body(block.body);
 
         // Create a new function context.
-        let def_id = anon_const.def_id;
+        let def_id = block.def_id;
         let fcx = FnCtxt::new(self, self.param_env.with_const(), def_id);
         crate::GatherLocalsVisitor::new(&fcx).visit_body(body);
 
         let ty = fcx.check_expr_with_expectation(&body.value, expected);
         fcx.require_type_is_sized(ty, body.value.span, traits::ConstSized);
-        fcx.write_ty(anon_const.hir_id, ty);
+        fcx.write_ty(block.hir_id, ty);
         ty
     }
 

compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs

@@ -270,6 +270,7 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> {
                 | hir::Node::Variant(..)
                 | hir::Node::Field(..)
                 | hir::Node::AnonConst(..)
+                | hir::Node::ConstBlock(..)
                 | hir::Node::Stmt(..)
                 | hir::Node::PathSegment(..)
                 | hir::Node::Ty(..)

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1191,7 +1191,7 @@ fn should_encode_type(tcx: TyCtxt<'_>, def_id: LocalDefId, def_kind: DefKind) ->
 
 fn should_encode_const(def_kind: DefKind) -> bool {
     match def_kind {
-        DefKind::Const | DefKind::AssocConst | DefKind::AnonConst => true,
+        DefKind::Const | DefKind::AssocConst | DefKind::AnonConst | DefKind::InlineConst => true,
 
         DefKind::Struct
         | DefKind::Union
@@ -1210,7 +1210,6 @@ fn should_encode_const(def_kind: DefKind) -> bool {
         | DefKind::Closure
         | DefKind::Generator
         | DefKind::ConstParam
-        | DefKind::InlineConst
         | DefKind::AssocTy
         | DefKind::TyParam
         | DefKind::Trait

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

@@ -44,6 +44,7 @@ pub fn associated_body(node: Node<'_>) -> Option<(LocalDefId, BodyId)> {
         }
 
         Node::AnonConst(constant) => Some((constant.def_id, constant.body)),
+        Node::ConstBlock(constant) => Some((constant.def_id, constant.body)),
 
         _ => None,
     }
@@ -240,15 +241,8 @@ impl<'hir> Map<'hir> {
                     None => bug!("constructor node without a constructor"),
                 }
             }
-            Node::AnonConst(_) => {
-                let inline = match self.find_parent(hir_id) {
-                    Some(Node::Expr(&Expr {
-                        kind: ExprKind::ConstBlock(ref anon_const), ..
-                    })) if anon_const.hir_id == hir_id => true,
-                    _ => false,
-                };
-                if inline { DefKind::InlineConst } else { DefKind::AnonConst }
-            }
+            Node::AnonConst(_) => DefKind::AnonConst,
+            Node::ConstBlock(_) => DefKind::InlineConst,
             Node::Field(_) => DefKind::Field,
             Node::Expr(expr) => match expr.kind {
                 ExprKind::Closure(Closure { movability: None, .. }) => DefKind::Closure,
@@ -1060,6 +1054,7 @@ impl<'hir> Map<'hir> {
             Node::Variant(variant) => variant.span,
             Node::Field(field) => field.span,
             Node::AnonConst(constant) => self.body(constant.body).value.span,
+            Node::ConstBlock(constant) => self.body(constant.body).value.span,
             Node::Expr(expr) => expr.span,
             Node::ExprField(field) => field.span,
             Node::Stmt(stmt) => stmt.span,
@@ -1289,6 +1284,7 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
             format!("{id} (field `{}` in {})", field.ident, path_str(field.def_id))
         }
         Some(Node::AnonConst(_)) => node_str("const"),
+        Some(Node::ConstBlock(_)) => node_str("const"),
         Some(Node::Expr(_)) => node_str("expr"),
         Some(Node::ExprField(_)) => node_str("expr field"),
         Some(Node::Stmt(_)) => node_str("stmt"),
@@ -1434,6 +1430,11 @@ impl<'hir> Visitor<'hir> for ItemCollector<'hir> {
         intravisit::walk_anon_const(self, c)
     }
 
+    fn visit_inline_const(&mut self, c: &'hir ConstBlock) {
+        self.body_owners.push(c.def_id);
+        intravisit::walk_inline_const(self, c)
+    }
+
     fn visit_expr(&mut self, ex: &'hir Expr<'hir>) {
         if let ExprKind::Closure(closure) = ex.kind {
             self.body_owners.push(closure.def_id);

compiler/rustc_mir_build/src/build/mod.rs

@@ -556,7 +556,7 @@ fn construct_const<'a, 'tcx>(
             span,
             ..
         }) => (*span, ty.span),
-        Node::AnonConst(_) => {
+        Node::AnonConst(_) | Node::ConstBlock(_) => {
             let span = tcx.def_span(def);
             (span, span)
         }

compiler/rustc_mir_build/src/thir/pattern/mod.rs

@@ -582,22 +582,15 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
     /// Converts inline const patterns.
     fn lower_inline_const(
         &mut self,
-        anon_const: &'tcx hir::AnonConst,
+        block: &'tcx hir::ConstBlock,
         id: hir::HirId,
         span: Span,
     ) -> PatKind<'tcx> {
         let tcx = self.tcx;
-        let def_id = anon_const.def_id;
-        let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
-        let body_id = match tcx.hir().get(hir_id) {
-            hir::Node::AnonConst(ac) => ac.body,
-            _ => span_bug!(
-                tcx.def_span(def_id.to_def_id()),
-                "from_inline_const can only process anonymous constants"
-            ),
-        };
+        let def_id = block.def_id;
+        let body_id = block.body;
         let expr = &tcx.hir().body(body_id).value;
-        let ty = tcx.typeck(def_id).node_type(hir_id);
+        let ty = tcx.typeck(def_id).node_type(block.hir_id);
 
         // Special case inline consts that are just literals. This is solely
         // a performance optimization, as we could also just go through the regular

compiler/rustc_mir_transform/src/check_unsafety.rs

@@ -421,10 +421,8 @@ impl<'tcx> intravisit::Visitor<'tcx> for UnusedUnsafeVisitor<'_, 'tcx> {
         intravisit::walk_block(self, block);
     }
 
-    fn visit_anon_const(&mut self, c: &'tcx hir::AnonConst) {
-        if matches!(self.tcx.def_kind(c.def_id), DefKind::InlineConst) {
-            self.visit_body(self.tcx.hir().body(c.body))
-        }
+    fn visit_inline_const(&mut self, c: &'tcx hir::ConstBlock) {
+        self.visit_body(self.tcx.hir().body(c.body))
     }
 
     fn visit_fn(