Revert "Create const block DefIds in typeck instead of ast lowering"

This reverts commit ddc5f9b6c1.

compiler/rustc_ast/src/ast.rs

@@ -1392,7 +1392,7 @@ pub enum ExprKind {
     /// An array (e.g, `[a, b, c, d]`).
     Array(ThinVec<P<Expr>>),
     /// Allow anonymous constants from an inline `const` block
-    ConstBlock(P<Expr>),
+    ConstBlock(AnonConst),
     /// A function call
     ///
     /// The first field resolves to the function itself,

compiler/rustc_ast/src/mut_visit.rs

@@ -1417,7 +1417,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
     match kind {
         ExprKind::Array(exprs) => visit_thin_exprs(exprs, vis),
         ExprKind::ConstBlock(anon_const) => {
-            vis.visit_expr(anon_const);
+            vis.visit_anon_const(anon_const);
         }
         ExprKind::Repeat(expr, count) => {
             vis.visit_expr(expr);

compiler/rustc_ast/src/visit.rs

@@ -959,7 +959,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) -> V
         ExprKind::Array(subexpressions) => {
             walk_list!(visitor, visit_expr, subexpressions);
         }
-        ExprKind::ConstBlock(anon_const) => try_visit!(visitor.visit_expr(anon_const)),
+        ExprKind::ConstBlock(anon_const) => try_visit!(visitor.visit_anon_const(anon_const)),
         ExprKind::Repeat(element, count) => {
             try_visit!(visitor.visit_expr(element));
             try_visit!(visitor.visit_anon_const(count));

compiler/rustc_ast_lowering/src/expr.rs

@@ -74,7 +74,14 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
             let kind = match &e.kind {
                 ExprKind::Array(exprs) => hir::ExprKind::Array(self.lower_exprs(exprs)),
-                ExprKind::ConstBlock(c) => hir::ExprKind::ConstBlock(self.lower_expr(c)),
+                ExprKind::ConstBlock(c) => {
+                    let c = self.with_new_scopes(c.value.span, |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);
                     let count = self.lower_array_length(count);

compiler/rustc_ast_lowering/src/index.rs

@@ -236,6 +236,14 @@ 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_ast_pretty/src/pprust/state/expr.rs

@@ -380,9 +380,8 @@ impl<'a> State<'a> {
             ast::ExprKind::Array(exprs) => {
                 self.print_expr_vec(exprs);
             }
-            ast::ExprKind::ConstBlock(expr) => {
+            ast::ExprKind::ConstBlock(anon_const) => {
-                self.word_space("const");
+                self.print_expr_anon_const(anon_const, attrs);
-                self.print_expr(expr, FixupContext::default());
             }
             ast::ExprKind::Repeat(element, count) => {
                 self.print_expr_repeat(element, count);

compiler/rustc_const_eval/src/const_eval/fn_queries.rs

@@ -38,6 +38,7 @@ fn constness(tcx: TyCtxt<'_>, def_id: LocalDefId) -> hir::Constness {
     match node {
         hir::Node::Ctor(_)
         | hir::Node::AnonConst(_)
+        | hir::Node::ConstBlock(_)
         | hir::Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Const(..), .. }) => {
             hir::Constness::Const
         }
@@ -56,7 +57,6 @@ fn constness(tcx: TyCtxt<'_>, def_id: LocalDefId) -> hir::Constness {
             if is_const { hir::Constness::Const } else { hir::Constness::NotConst }
         }
         hir::Node::Expr(e) if let hir::ExprKind::Closure(c) = e.kind => c.constness,
-        hir::Node::Expr(e) if let hir::ExprKind::ConstBlock(_) = e.kind => hir::Constness::Const,
         _ => {
             if let Some(fn_kind) = node.fn_kind() {
                 if fn_kind.constness() == hir::Constness::Const {

compiler/rustc_hir/src/hir.rs

@@ -1623,6 +1623,14 @@ pub struct AnonConst {
     pub span: Span,
 }
 
+/// 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> {
@@ -1909,7 +1917,7 @@ 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(&'hir Expr<'hir>),
+    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>),
@@ -3701,6 +3710,7 @@ impl<'hir> Node<'hir> {
             Node::PreciseCapturingNonLifetimeArg(a) => Some(a.ident),
             Node::Param(..)
             | Node::AnonConst(..)
+            | Node::ConstBlock(..)
             | Node::Expr(..)
             | Node::Stmt(..)
             | Node::Block(..)
@@ -3798,6 +3808,7 @@ impl<'hir> Node<'hir> {
             }
 
             Node::AnonConst(constant) => Some((constant.def_id, constant.body)),
+            Node::ConstBlock(constant) => Some((constant.def_id, constant.body)),
 
             _ => None,
         }
@@ -3866,6 +3877,7 @@ impl<'hir> Node<'hir> {
         expect_variant,       &'hir Variant<'hir>,      Node::Variant(n),      n;
         expect_field,         &'hir FieldDef<'hir>,     Node::Field(n),        n;
         expect_anon_const,    &'hir AnonConst,          Node::AnonConst(n),    n;
+        expect_inline_const,  &'hir ConstBlock,         Node::ConstBlock(n),   n;
         expect_expr,          &'hir Expr<'hir>,         Node::Expr(n),         n;
         expect_expr_field,    &'hir ExprField<'hir>,    Node::ExprField(n),    n;
         expect_stmt,          &'hir Stmt<'hir>,         Node::Stmt(n),         n;

compiler/rustc_hir/src/intravisit.rs

@@ -344,6 +344,9 @@ pub trait Visitor<'v>: Sized {
     fn visit_anon_const(&mut self, c: &'v AnonConst) -> Self::Result {
         walk_anon_const(self, c)
     }
+    fn visit_inline_const(&mut self, c: &'v ConstBlock) -> Self::Result {
+        walk_inline_const(self, c)
+    }
     fn visit_expr(&mut self, ex: &'v Expr<'v>) -> Self::Result {
         walk_expr(self, ex)
     }
@@ -718,6 +721,14 @@ 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,
+) -> V::Result {
+    try_visit!(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>) -> V::Result {
     try_visit!(visitor.visit_id(expression.hir_id));
     match expression.kind {
@@ -725,7 +736,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>)
             walk_list!(visitor, visit_expr, subexpressions);
         }
         ExprKind::ConstBlock(ref const_block) => {
-            try_visit!(visitor.visit_expr(const_block))
+            try_visit!(visitor.visit_inline_const(const_block))
         }
         ExprKind::Repeat(ref element, ref count) => {
             try_visit!(visitor.visit_expr(element));

compiler/rustc_hir_analysis/src/check/region.rs

@@ -407,14 +407,11 @@ fn resolve_expr<'tcx>(visitor: &mut RegionResolutionVisitor<'tcx>, expr: &'tcx h
     match expr.kind {
         // 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::Closure(&hir::Closure { body, .. })
+        | hir::ExprKind::ConstBlock(hir::ConstBlock { body, .. }) => {
             let body = visitor.tcx.hir().body(body);
             visitor.visit_body(body);
         }
-        hir::ExprKind::ConstBlock(expr) => visitor.enter_body(expr.hir_id, |this| {
-            this.cx.var_parent = None;
-            resolve_local(this, None, Some(expr));
-        }),
         hir::ExprKind::AssignOp(_, left_expr, right_expr) => {
             debug!(
                 "resolve_expr - enabling pessimistic_yield, was previously {}",

compiler/rustc_hir_analysis/src/collect/generics_of.rs

@@ -177,10 +177,10 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                 }
             }
         }
-        Node::Expr(&hir::Expr {
+        Node::ConstBlock(_)
-            kind: hir::ExprKind::Closure { .. } | hir::ExprKind::ConstBlock { .. },
+        | Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => {
-            ..
+            Some(tcx.typeck_root_def_id(def_id.to_def_id()))
-        }) => Some(tcx.typeck_root_def_id(def_id.to_def_id())),
+        }
         Node::Item(item) => match item.kind {
             ItemKind::OpaqueTy(&hir::OpaqueTy {
                 origin:
@@ -415,7 +415,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
     }
 
     // provide junk type parameter defs for const blocks.
-    if let Node::Expr(Expr { kind: ExprKind::ConstBlock(..), .. }) = node {
+    if let Node::ConstBlock(_) = node {
         own_params.push(ty::GenericParamDef {
             index: next_index(),
             name: Symbol::intern("<const_ty>"),

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -485,7 +485,8 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_
         }
 
         Node::AnonConst(_) => anon_const_type_of(tcx, def_id),
-        Node::Expr(&Expr { kind: ExprKind::ConstBlock(..), .. }) => {
+
+        Node::ConstBlock(_) => {
             let args = ty::GenericArgs::identity_for_item(tcx, def_id.to_def_id());
             args.as_inline_const().ty()
         }

compiler/rustc_hir_analysis/src/lib.rs

@@ -190,6 +190,10 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
         }
     });
 
+    // Freeze definitions as we don't add new ones at this point. This improves performance by
+    // allowing lock-free access to them.
+    tcx.untracked().definitions.freeze();
+
     // FIXME: Remove this when we implement creating `DefId`s
     // for anon constants during their parents' typeck.
     // Typeck all body owners in parallel will produce queries
@@ -201,10 +205,6 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
         }
     });
 
-    // Freeze definitions as we don't add new ones at this point. This improves performance by
-    // allowing lock-free access to them.
-    tcx.untracked().definitions.freeze();
-
     tcx.ensure().check_unused_traits(());
 }
 

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),
@@ -1049,10 +1050,10 @@ impl<'a> State<'a> {
         self.end()
     }
 
-    fn print_inline_const(&mut self, constant: &hir::Expr<'_>) {
+    fn print_inline_const(&mut self, constant: &hir::ConstBlock) {
         self.ibox(INDENT_UNIT);
         self.word_space("const");
-        self.print_expr(constant);
+        self.ann.nested(self, Nested::Body(constant.body));
         self.end()
     }
 

compiler/rustc_hir_typeck/src/expr.rs

@@ -31,6 +31,7 @@ use rustc_errors::{
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::DefId;
+use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{ExprKind, HirId, QPath};
 use rustc_hir_analysis::hir_ty_lowering::HirTyLowerer as _;
@@ -334,7 +335,7 @@ 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 block) => self.check_expr_with_expectation(block, expected),
+            ExprKind::ConstBlock(ref block) => self.check_expr_const_block(block, expected),
             ExprKind::Repeat(element, ref count) => {
                 self.check_expr_repeat(element, count, expected, expr)
             }
@@ -1456,6 +1457,24 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
+    fn check_expr_const_block(
+        &self,
+        block: &'tcx hir::ConstBlock,
+        expected: Expectation<'tcx>,
+    ) -> Ty<'tcx> {
+        let body = self.tcx.hir().body(block.body);
+
+        // Create a new function context.
+        let def_id = block.def_id;
+        let fcx = FnCtxt::new(self, self.param_env, 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, ObligationCauseCode::ConstSized);
+        fcx.write_ty(block.hir_id, ty);
+        ty
+    }
+
     fn check_expr_repeat(
         &self,
         element: &'tcx hir::Expr<'tcx>,

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -1051,10 +1051,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 .take_while(|(_, node)| {
                     // look at parents until we find the first body owner
                     node.body_id().is_none()
-                        && !matches!(
-                            node,
-                            Node::Expr(Expr { kind: ExprKind::ConstBlock { .. }, .. })
-                        )
                 })
                 .any(|(parent_id, _)| self.is_loop(parent_id));
 

compiler/rustc_hir_typeck/src/upvar.rs

@@ -149,6 +149,10 @@ impl<'a, 'tcx> Visitor<'tcx> for InferBorrowKindVisitor<'a, 'tcx> {
                 self.visit_body(body);
                 self.fcx.analyze_closure(expr.hir_id, expr.span, body_id, body, capture_clause);
             }
+            hir::ExprKind::ConstBlock(anon_const) => {
+                let body = self.fcx.tcx.hir().body(anon_const.body);
+                self.visit_body(body);
+            }
             _ => {}
         }
 

compiler/rustc_hir_typeck/src/writeback.rs

@@ -3,7 +3,6 @@
 // generic parameters.
 
 use crate::FnCtxt;
-use hir::def::DefKind;
 use rustc_data_structures::unord::ExtendUnord;
 use rustc_errors::{ErrorGuaranteed, StashKey};
 use rustc_hir as hir;
@@ -17,7 +16,7 @@ use rustc_middle::ty::fold::{TypeFoldable, TypeFolder};
 use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::TypeSuperFoldable;
 use rustc_middle::ty::{self, Ty, TyCtxt};
-use rustc_span::symbol::{kw, sym};
+use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_trait_selection::solve;
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
@@ -296,11 +295,11 @@ impl<'cx, 'tcx> Visitor<'tcx> for WritebackCx<'cx, 'tcx> {
             hir::ExprKind::Field(..) | hir::ExprKind::OffsetOf(..) => {
                 self.visit_field_id(e.hir_id);
             }
-            hir::ExprKind::ConstBlock(_) => {
+            hir::ExprKind::ConstBlock(anon_const) => {
-                let feed = self.tcx().create_def(self.fcx.body_id, kw::Empty, DefKind::InlineConst);
+                self.visit_node_id(e.span, anon_const.hir_id);
-                feed.def_span(e.span);
+
-                feed.local_def_id_to_hir_id(e.hir_id);
+                let body = self.tcx().hir().body(anon_const.body);
-                self.typeck_results.inline_consts.insert(e.hir_id.local_id, feed.def_id());
+                self.visit_body(body);
             }
             _ => {}
         }

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

@@ -1,5 +1,3 @@
-use std::borrow::Cow;
-
 use crate::hir::ModuleItems;
 use crate::middle::debugger_visualizer::DebuggerVisualizerFile;
 use crate::query::LocalCrate;
@@ -256,26 +254,13 @@ impl<'hir> Map<'hir> {
 
     /// Given a `LocalDefId`, returns the `BodyId` associated with it,
     /// if the node is a body owner, otherwise returns `None`.
-    pub fn maybe_body_owned_by(self, id: LocalDefId) -> Option<Cow<'hir, Body<'hir>>> {
+    pub fn maybe_body_owned_by(self, id: LocalDefId) -> Option<&'hir Body<'hir>> {
-        Some(match self.tcx.def_kind(id) {
+        Some(self.body(self.tcx.hir_node_by_def_id(id).body_id()?))
-            // Inline consts do not have bodies of their own, so create one to make the follow-up logic simpler.
-            DefKind::InlineConst => {
-                let e = self.expect_expr(self.tcx.local_def_id_to_hir_id(id));
-                Cow::Owned(Body {
-                    params: &[],
-                    value: match e.kind {
-                        ExprKind::ConstBlock(body) => body,
-                        _ => span_bug!(e.span, "InlineConst was not a ConstBlock: {e:#?}"),
-                    },
-                })
-            }
-            _ => Cow::Borrowed(self.body(self.tcx.hir_node_by_def_id(id).body_id()?)),
-        })
     }
 
     /// Given a body owner's id, returns the `BodyId` associated with it.
     #[track_caller]
-    pub fn body_owned_by(self, id: LocalDefId) -> Cow<'hir, Body<'hir>> {
+    pub fn body_owned_by(self, id: LocalDefId) -> &'hir Body<'hir> {
         self.maybe_body_owned_by(id).unwrap_or_else(|| {
             let hir_id = self.tcx.local_def_id_to_hir_id(id);
             span_bug!(
@@ -338,7 +323,7 @@ impl<'hir> Map<'hir> {
 
     /// 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().owners.iter()`.
+    /// themselves, you can do `self.hir().krate().body_ids.iter()`.
     #[inline]
     pub fn body_owners(self) -> impl Iterator<Item = LocalDefId> + 'hir {
         self.tcx.hir_crate_items(()).body_owners.iter().copied()
@@ -525,17 +510,7 @@ impl<'hir> Map<'hir> {
     /// Whether the expression pointed at by `hir_id` belongs to a `const` evaluation context.
     /// Used exclusively for diagnostics, to avoid suggestion function calls.
     pub fn is_inside_const_context(self, hir_id: HirId) -> bool {
-        for (_, node) in self.parent_iter(hir_id) {
+        self.body_const_context(self.enclosing_body_owner(hir_id)).is_some()
-            if let Some((def_id, _)) = node.associated_body() {
-                return self.body_const_context(def_id).is_some();
-            }
-            if let Node::Expr(e) = node {
-                if let ExprKind::ConstBlock(_) = e.kind {
-                    return true;
-                }
-            }
-        }
-        false
     }
 
     /// Retrieves the `HirId` for `id`'s enclosing function *if* the `id` block or return is
@@ -918,6 +893,7 @@ impl<'hir> Map<'hir> {
             Node::Variant(variant) => variant.span,
             Node::Field(field) => field.span,
             Node::AnonConst(constant) => constant.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,
@@ -1187,6 +1163,7 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
             format!("{id} (field `{}` in {})", field.ident, path_str(field.def_id))
         }
         Node::AnonConst(_) => node_str("const"),
+        Node::ConstBlock(_) => node_str("const"),
         Node::Expr(_) => node_str("expr"),
         Node::ExprField(_) => node_str("expr field"),
         Node::Stmt(_) => node_str("stmt"),
@@ -1336,6 +1313,11 @@ 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_middle/src/ty/typeck_results.rs

@@ -217,10 +217,6 @@ pub struct TypeckResults<'tcx> {
 
     /// Container types and field indices of `offset_of!` expressions
     offset_of_data: ItemLocalMap<(Ty<'tcx>, Vec<(VariantIdx, FieldIdx)>)>,
-
-    /// Maps from `HirId`s of const blocks (the `ExprKind::ConstBlock`, not the inner expression's)
-    /// to the `DefId` of the corresponding inline const.
-    pub inline_consts: FxIndexMap<ItemLocalId, LocalDefId>,
 }
 
 impl<'tcx> TypeckResults<'tcx> {
@@ -253,7 +249,6 @@ impl<'tcx> TypeckResults<'tcx> {
             treat_byte_string_as_slice: Default::default(),
             closure_size_eval: Default::default(),
             offset_of_data: Default::default(),
-            inline_consts: Default::default(),
         }
     }
 

compiler/rustc_mir_build/src/build/mod.rs

@@ -568,8 +568,11 @@ fn construct_const<'a, 'tcx>(
             ..
         }) => (*span, ty.span),
         Node::AnonConst(ct) => (ct.span, ct.span),
-        Node::Expr(&hir::Expr { span, kind: hir::ExprKind::ConstBlock(_), .. }) => (span, span),
+        Node::ConstBlock(_) => {
-        node => span_bug!(tcx.def_span(def), "can't build MIR for {def:?}: {node:#?}"),
+            let span = tcx.def_span(def);
+            (span, span)
+        }
+        _ => span_bug!(tcx.def_span(def), "can't build MIR for {:?}", def),
     };
 
     let infcx = tcx.infer_ctxt().build();

compiler/rustc_mir_build/src/thir/cx/expr.rs

@@ -671,9 +671,9 @@ impl<'tcx> Cx<'tcx> {
                 ExprKind::OffsetOf { container, fields }
             }
 
-            hir::ExprKind::ConstBlock(body) => {
+            hir::ExprKind::ConstBlock(ref anon_const) => {
-                let ty = self.typeck_results().node_type(body.hir_id);
+                let ty = self.typeck_results().node_type(anon_const.hir_id);
-                let did = self.typeck_results().inline_consts[&expr.hir_id.local_id].into();
+                let did = anon_const.def_id.to_def_id();
                 let typeck_root_def_id = tcx.typeck_root_def_id(did);
                 let parent_args =
                     tcx.erase_regions(GenericArgs::identity_for_item(tcx, typeck_root_def_id));

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

@@ -165,7 +165,7 @@ impl<'tcx> Cx<'tcx> {
         &'a mut self,
         owner_id: HirId,
         fn_decl: &'tcx hir::FnDecl<'tcx>,
-        body: &hir::Body<'tcx>,
+        body: &'tcx hir::Body<'tcx>,
     ) -> impl Iterator<Item = Param<'tcx>> + 'a {
         let fn_sig = self.typeck_results.liberated_fn_sigs()[owner_id];
 

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

@@ -637,13 +637,15 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
     /// Converts inline const patterns.
     fn lower_inline_const(
         &mut self,
-        expr: &'tcx hir::Expr<'tcx>,
+        block: &'tcx hir::ConstBlock,
         id: hir::HirId,
         span: Span,
     ) -> PatKind<'tcx> {
         let tcx = self.tcx;
-        let def_id = self.typeck_results.inline_consts[&id.local_id];
+        let def_id = block.def_id;
-        let ty = tcx.typeck(def_id).node_type(expr.hir_id);
+        let body_id = block.body;
+        let expr = &tcx.hir().body(body_id).value;
+        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/lib.rs

@@ -222,12 +222,6 @@ fn mir_keys(tcx: TyCtxt<'_>, (): ()) -> FxIndexSet<LocalDefId> {
     // All body-owners have MIR associated with them.
     set.extend(tcx.hir().body_owners());
 
-    // Inline consts' bodies are created in
-    // typeck instead of during ast lowering, like all other bodies so far.
-    for def_id in tcx.hir().body_owners() {
-        set.extend(tcx.typeck(def_id).inline_consts.values())
-    }
-
     // Additionally, tuple struct/variant constructors have MIR, but
     // they don't have a BodyId, so we need to build them separately.
     struct GatherCtors<'a> {

compiler/rustc_parse/src/parser/mod.rs

@@ -25,8 +25,8 @@ use rustc_ast::tokenstream::{AttributesData, DelimSpacing, DelimSpan, Spacing};
 use rustc_ast::tokenstream::{TokenStream, TokenTree, TokenTreeCursor};
 use rustc_ast::util::case::Case;
 use rustc_ast::{
-    self as ast, AttrArgs, AttrArgsEq, AttrId, ByRef, Const, CoroutineKind, DelimArgs, Expr,
+    self as ast, AnonConst, AttrArgs, AttrArgsEq, AttrId, ByRef, Const, CoroutineKind, DelimArgs,
-    ExprKind, Extern, HasAttrs, HasTokens, Mutability, Recovered, Safety, StrLit, Visibility,
+    Expr, ExprKind, Extern, HasAttrs, HasTokens, Mutability, Recovered, Safety, StrLit, Visibility,
     VisibilityKind, DUMMY_NODE_ID,
 };
 use rustc_ast_pretty::pprust;
@@ -1262,9 +1262,12 @@ impl<'a> Parser<'a> {
         }
         self.eat_keyword(kw::Const);
         let (attrs, blk) = self.parse_inner_attrs_and_block()?;
-        let expr = self.mk_expr(blk.span, ExprKind::Block(blk, None));
+        let anon_const = AnonConst {
-        let blk_span = expr.span;
+            id: DUMMY_NODE_ID,
-        Ok(self.mk_expr_with_attrs(span.to(blk_span), ExprKind::ConstBlock(expr), attrs))
+            value: self.mk_expr(blk.span, ExprKind::Block(blk, None)),
+        };
+        let blk_span = anon_const.value.span;
+        Ok(self.mk_expr_with_attrs(span.to(blk_span), ExprKind::ConstBlock(anon_const), attrs))
     }
 
     /// Parses mutability (`mut` or nothing).

compiler/rustc_passes/src/check_const.rs

@@ -196,6 +196,11 @@ impl<'tcx> Visitor<'tcx> for CheckConstVisitor<'tcx> {
         self.recurse_into(kind, None, |this| intravisit::walk_anon_const(this, anon));
     }
 
+    fn visit_inline_const(&mut self, block: &'tcx hir::ConstBlock) {
+        let kind = Some(hir::ConstContext::Const { inline: true });
+        self.recurse_into(kind, None, |this| intravisit::walk_inline_const(this, block));
+    }
+
     fn visit_body(&mut self, body: &hir::Body<'tcx>) {
         let owner = self.tcx.hir().body_owner_def_id(body.id());
         let kind = self.tcx.hir().body_const_context(owner);
@@ -223,11 +228,6 @@ impl<'tcx> Visitor<'tcx> for CheckConstVisitor<'tcx> {
                     self.const_check_violated(expr, e.span);
                 }
             }
-            hir::ExprKind::ConstBlock(expr) => {
-                let kind = Some(hir::ConstContext::Const { inline: true });
-                self.recurse_into(kind, None, |this| intravisit::walk_expr(this, expr));
-                return;
-            }
 
             _ => {}
         }

compiler/rustc_passes/src/dead.rs

@@ -587,16 +587,6 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
             hir::ExprKind::OffsetOf(..) => {
                 self.handle_offset_of(expr);
             }
-            hir::ExprKind::ConstBlock(expr) => {
-                // When inline const blocks are used in pattern position, paths
-                // referenced by it should be considered as used.
-                let in_pat = mem::replace(&mut self.in_pat, false);
-
-                intravisit::walk_expr(self, expr);
-
-                self.in_pat = in_pat;
-                return;
-            }
             _ => (),
         }
 
@@ -658,6 +648,17 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
 
         self.in_pat = in_pat;
     }
+
+    fn visit_inline_const(&mut self, c: &'tcx hir::ConstBlock) {
+        // When inline const blocks are used in pattern position, paths
+        // referenced by it should be considered as used.
+        let in_pat = mem::replace(&mut self.in_pat, false);
+
+        self.live_symbols.insert(c.def_id);
+        intravisit::walk_inline_const(self, c);
+
+        self.in_pat = in_pat;
+    }
 }
 
 fn has_allow_dead_code_or_lang_attr(

compiler/rustc_passes/src/liveness.rs

@@ -147,11 +147,6 @@ fn check_liveness(tcx: TyCtxt<'_>, def_id: LocalDefId) {
         return;
     }
 
-    // Don't run for inline consts, they are collected together with their parent
-    if let DefKind::InlineConst = tcx.def_kind(def_id) {
-        return;
-    }
-
     // Don't run unused pass for #[naked]
     if tcx.has_attr(def_id.to_def_id(), sym::naked) {
         return;
@@ -1148,13 +1143,12 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             }
 
             hir::ExprKind::Lit(..)
+            | hir::ExprKind::ConstBlock(..)
             | hir::ExprKind::Err(_)
             | hir::ExprKind::Path(hir::QPath::TypeRelative(..))
             | hir::ExprKind::Path(hir::QPath::LangItem(..))
             | hir::ExprKind::OffsetOf(..) => succ,
 
-            hir::ExprKind::ConstBlock(expr) => self.propagate_through_expr(expr, succ),
-
             // Note that labels have been resolved, so we don't need to look
             // at the label ident
             hir::ExprKind::Block(ref blk, _) => self.propagate_through_block(blk, succ),

compiler/rustc_passes/src/loops.rs

@@ -93,6 +93,10 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
         self.with_context(Constant, |v| intravisit::walk_anon_const(v, c));
     }
 
+    fn visit_inline_const(&mut self, c: &'hir hir::ConstBlock) {
+        self.with_context(Constant, |v| intravisit::walk_inline_const(v, c));
+    }
+
     fn visit_fn(
         &mut self,
         fk: hir::intravisit::FnKind<'hir>,
@@ -285,9 +289,6 @@ impl<'a, 'hir> Visitor<'hir> for CheckLoopVisitor<'a, 'hir> {
                     self.cx_stack.len() - 1,
                 )
             }
-            hir::ExprKind::ConstBlock(expr) => {
-                self.with_context(Constant, |v| intravisit::walk_expr(v, expr));
-            }
             _ => intravisit::walk_expr(self, e),
         }
     }

compiler/rustc_resolve/src/def_collector.rs

@@ -340,6 +340,16 @@ impl<'a, 'b, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'b, 'tcx> {
             ExprKind::Gen(_, _, _) => {
                 self.create_def(expr.id, kw::Empty, DefKind::Closure, expr.span)
             }
+            ExprKind::ConstBlock(ref constant) => {
+                let def = self.create_def(
+                    constant.id,
+                    kw::Empty,
+                    DefKind::InlineConst,
+                    constant.value.span,
+                );
+                self.with_parent(def, |this| visit::walk_anon_const(this, constant));
+                return;
+            }
             _ => self.parent_def,
         };
 

compiler/rustc_resolve/src/late.rs

@@ -4535,10 +4535,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 self.visit_expr(elem);
                 self.resolve_anon_const(ct, AnonConstKind::ConstArg(IsRepeatExpr::Yes));
             }
-            ExprKind::ConstBlock(ref expr) => {
+            ExprKind::ConstBlock(ref ct) => {
-                self.resolve_anon_const_manual(false, AnonConstKind::InlineConst, |this| {
+                self.resolve_anon_const(ct, AnonConstKind::InlineConst);
-                    this.visit_expr(expr)
-                });
             }
             ExprKind::Index(ref elem, ref idx, _) => {
                 self.resolve_expr(elem, Some(expr));

src/tools/clippy/clippy_utils/src/consts.rs

@@ -6,7 +6,7 @@ use crate::{clip, is_direct_expn_of, sext, unsext};
 use rustc_ast::ast::{self, LitFloatType, LitKind};
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, Item, ItemKind, Node, QPath, UnOp};
+use rustc_hir::{BinOp, BinOpKind, Block, ConstBlock, Expr, ExprKind, HirId, Item, ItemKind, Node, QPath, UnOp};
 use rustc_lexer::tokenize;
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::{alloc_range, Scalar};
@@ -412,7 +412,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// Simple constant folding: Insert an expression, get a constant or none.
     pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant<'tcx>> {
         match e.kind {
-            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr(e),
+            ExprKind::ConstBlock(ConstBlock { body, .. }) => self.expr(self.lcx.tcx.hir().body(body).value), ExprKind::DropTemps(e) => self.expr(e),
             ExprKind::Path(ref qpath) => {
                 self.fetch_path_and_apply(qpath, e.hir_id, self.typeck_results.expr_ty(e), |this, result| {
                     let result = mir_to_const(this.lcx, result)?;
@@ -490,7 +490,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// leaves the local crate.
     pub fn expr_is_empty(&mut self, e: &Expr<'_>) -> Option<bool> {
         match e.kind {
-            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr_is_empty(e),
+            ExprKind::ConstBlock(ConstBlock { body, .. }) => self.expr_is_empty(self.lcx.tcx.hir().body(body).value), ExprKind::DropTemps(e) => self.expr_is_empty(e),
             ExprKind::Path(ref qpath) => {
                 if !self
                     .typeck_results

src/tools/clippy/clippy_utils/src/hir_utils.rs

@@ -295,7 +295,7 @@ impl HirEqInterExpr<'_, '_, '_> {
                 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
             },
             (&ExprKind::Closure(_l), &ExprKind::Closure(_r)) => false,
-            (&ExprKind::ConstBlock(lb), &ExprKind::ConstBlock(rb)) => self.eq_expr(lb, rb),
+            (&ExprKind::ConstBlock(lb), &ExprKind::ConstBlock(rb)) => self.eq_body(lb.body, rb.body),
             (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
                 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
             },
@@ -769,8 +769,8 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                 // closures inherit TypeckResults
                 self.hash_expr(self.cx.tcx.hir().body(body).value);
             },
-            ExprKind::ConstBlock(l_id) => {
+            ExprKind::ConstBlock(ref l_id) => {
-                self.hash_expr(l_id);
+                self.hash_body(l_id.body);
             },
             ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
                 self.hash_expr(e);

src/tools/clippy/tests/ui/arithmetic_side_effects.stderr

@@ -1,35 +1,11 @@
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:188:36
-   |
-LL |     let _ = const { let mut n = 1; n += 1; n };
-   |                                    ^^^^^^
-   |
-   = note: `-D clippy::arithmetic-side-effects` implied by `-D warnings`
-   = help: to override `-D warnings` add `#[allow(clippy::arithmetic_side_effects)]`
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:191:40
-   |
-LL |     let _ = const { let mut n = 1; n = n + 1; n };
-   |                                        ^^^^^
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:194:40
-   |
-LL |     let _ = const { let mut n = 1; n = 1 + n; n };
-   |                                        ^^^^^
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:200:59
-   |
-LL |     let _ = const { let mut n = 1; n = -1; n = -(-1); n = -n; n };
-   |                                                           ^^
-
 error: arithmetic operation that can potentially result in unexpected side-effects
   --> tests/ui/arithmetic_side_effects.rs:304:5
    |
 LL |     _n += 1;
    |     ^^^^^^^
+   |
+   = note: `-D clippy::arithmetic-side-effects` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::arithmetic_side_effects)]`
 
 error: arithmetic operation that can potentially result in unexpected side-effects
   --> tests/ui/arithmetic_side_effects.rs:305:5
@@ -751,5 +727,5 @@ error: arithmetic operation that can potentially result in unexpected side-effec
 LL |     one.sub_assign(1);
    |     ^^^^^^^^^^^^^^^^^
 
-error: aborting due to 125 previous errors
+error: aborting due to 121 previous errors
 

tests/mir-opt/building/custom/consts.consts.built.after.mir

@@ -10,7 +10,7 @@ fn consts() -> () {
 
     bb0: {
         _1 = const 5_u8;
-        _2 = const consts::<C>::{constant#1};
+        _2 = const consts::<C>::{constant#0};
         _3 = const C;
         _4 = const D;
         _5 = consts::<10>;

tests/pretty/stmt_expr_attributes.rs

@@ -206,7 +206,12 @@ fn _11() {
             let _ = ();
             ()
         };
-    let const {} = #[rustc_dummy] const {};
+    let const {
+                    #![rustc_dummy]
+                } =
+        #[rustc_dummy] const {
+                #![rustc_dummy]
+            };
     let mut x = 0;
     let _ = (#[rustc_dummy] x) = 15;
     let _ = (#[rustc_dummy] x) += 15;

tests/ui/lint/non-local-defs/consts.stderr

@@ -67,13 +67,18 @@ LL |     impl Test {
 warning: non-local `impl` definition, `impl` blocks should be written at the same level as their item
   --> $DIR/consts.rs:50:9
    |
-LL | fn main() {
+LL |       const {
-   | --------- move the `impl` block outside of this function `main`
+   |  ___________-
-...
+LL | |         impl Test {
-LL |         impl Test {
+   | |         ^^^^^----
-   |         ^^^^^----
+   | |              |
-   |              |
+   | |              `Test` is not local
-   |              `Test` is not local
+LL | |
+LL | |             fn hoo() {}
+...  |
+LL | |         1
+LL | |     };
+   | |_____- move the `impl` block outside of this inline constant `<unnameable>` and up 2 bodies
    |
    = note: methods and associated constants are still usable outside the current expression, only `impl Local` and `impl dyn Local` can ever be private, and only if the type is nested in the same item as the `impl`
    = note: this lint may become deny-by-default in the edition 2024 and higher, see the tracking issue <https://github.com/rust-lang/rust/issues/120363>

tests/ui/unpretty/expanded-exhaustive.stdout

@@ -83,8 +83,7 @@ mod expressions {
     fn expr_const_block() {
         const {};
         const { 1 };
-        const
+        const {
-            {
                 struct S;
             };
     }