Create const block DefIds in typeck instead of ast lowering

compiler/rustc_ast/src/ast.rs

@@ -1393,7 +1393,7 @@ pub enum ExprKind {
     /// An array (e.g, `[a, b, c, d]`).
     Array(ThinVec<P<Expr>>),
     /// Allow anonymous constants from an inline `const` block
-    ConstBlock(AnonConst),
+    ConstBlock(P<Expr>),
     /// A function call
     ///
     /// The first field resolves to the function itself,

compiler/rustc_ast/src/mut_visit.rs

@@ -1411,7 +1411,7 @@ pub fn noop_visit_expr<T: MutVisitor>(
     match kind {
         ExprKind::Array(exprs) => visit_thin_exprs(exprs, vis),
         ExprKind::ConstBlock(anon_const) => {
-            vis.visit_anon_const(anon_const);
+            vis.visit_expr(anon_const);
         }
         ExprKind::Repeat(expr, count) => {
             vis.visit_expr(expr);

compiler/rustc_ast/src/visit.rs

@@ -951,7 +951,7 @@ 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_anon_const(anon_const)),
+        ExprKind::ConstBlock(anon_const) => try_visit!(visitor.visit_expr(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

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

@@ -236,14 +236,6 @@ 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

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

@@ -38,7 +38,6 @@ 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
         }

compiler/rustc_hir/src/hir.rs

@@ -1592,14 +1592,6 @@ 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> {
@@ -1886,7 +1878,7 @@ 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(ConstBlock),
+    ConstBlock(&'hir Expr<'hir>),
     /// An array (e.g., `[a, b, c, d]`).
     Array(&'hir [Expr<'hir>]),
     /// A function call.
@@ -3609,7 +3601,6 @@ 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>),
@@ -3670,7 +3661,6 @@ impl<'hir> Node<'hir> {
             Node::PreciseCapturingNonLifetimeArg(a) => Some(a.ident),
             Node::Param(..)
             | Node::AnonConst(..)
-            | Node::ConstBlock(..)
             | Node::Expr(..)
             | Node::Stmt(..)
             | Node::Block(..)
@@ -3768,7 +3758,6 @@ impl<'hir> Node<'hir> {
             }
 
             Node::AnonConst(constant) => Some((constant.def_id, constant.body)),
-            Node::ConstBlock(constant) => Some((constant.def_id, constant.body)),
 
             _ => None,
         }
@@ -3837,7 +3826,6 @@ 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

@@ -344,9 +344,6 @@ 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)
     }
@@ -716,22 +713,14 @@ 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 {
         ExprKind::Array(subexpressions) => {
             walk_list!(visitor, visit_expr, subexpressions);
         }
         ExprKind::ConstBlock(ref const_block) => {
-            try_visit!(visitor.visit_inline_const(const_block))
+            try_visit!(visitor.visit_expr(const_block))
         }
         ExprKind::Repeat(ref element, ref count) => {
             try_visit!(visitor.visit_expr(element));

compiler/rustc_hir_analysis/src/check/region.rs

@@ -407,11 +407,14 @@ 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::ConstBlock(hir::ConstBlock { body, .. }) => {
+        hir::ExprKind::Closure(&hir::Closure { 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 {}",
@@ -782,25 +785,8 @@ impl<'tcx> RegionResolutionVisitor<'tcx> {
         }
         self.enter_scope(Scope { id, data: ScopeData::Node });
     }
-}
-
-impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
-    fn visit_block(&mut self, b: &'tcx Block<'tcx>) {
-        resolve_block(self, b);
-    }
-
-    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
-        let body_id = body.id();
-        let owner_id = self.tcx.hir().body_owner_def_id(body_id);
-
-        debug!(
-            "visit_body(id={:?}, span={:?}, body.id={:?}, cx.parent={:?})",
-            owner_id,
-            self.tcx.sess.source_map().span_to_diagnostic_string(body.value.span),
-            body_id,
-            self.cx.parent
-        );
 
+    fn enter_body(&mut self, hir_id: hir::HirId, f: impl FnOnce(&mut Self)) {
         // Save all state that is specific to the outer function
         // body. These will be restored once down below, once we've
         // visited the body.
@@ -812,50 +798,73 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
         // control flow assumptions. This doesn't apply to nested
         // bodies within the `+=` statements. See #69307.
         let outer_pessimistic_yield = mem::replace(&mut self.pessimistic_yield, false);
-        self.terminating_scopes.insert(body.value.hir_id.local_id);
-
-        self.enter_scope(Scope { id: body.value.hir_id.local_id, data: ScopeData::CallSite });
-        self.enter_scope(Scope { id: body.value.hir_id.local_id, data: ScopeData::Arguments });
+        self.terminating_scopes.insert(hir_id.local_id);
 
-        // The arguments and `self` are parented to the fn.
-        self.cx.var_parent = self.cx.parent.take();
-        for param in body.params {
-            self.visit_pat(param.pat);
-        }
+        self.enter_scope(Scope { id: hir_id.local_id, data: ScopeData::CallSite });
+        self.enter_scope(Scope { id: hir_id.local_id, data: ScopeData::Arguments });
 
-        // The body of the every fn is a root scope.
-        self.cx.parent = self.cx.var_parent;
-        if self.tcx.hir().body_owner_kind(owner_id).is_fn_or_closure() {
-            self.visit_expr(body.value)
-        } else {
-            // Only functions have an outer terminating (drop) scope, while
-            // temporaries in constant initializers may be 'static, but only
-            // according to rvalue lifetime semantics, using the same
-            // syntactical rules used for let initializers.
-            //
-            // e.g., in `let x = &f();`, the temporary holding the result from
-            // the `f()` call lives for the entirety of the surrounding block.
-            //
-            // Similarly, `const X: ... = &f();` would have the result of `f()`
-            // live for `'static`, implying (if Drop restrictions on constants
-            // ever get lifted) that the value *could* have a destructor, but
-            // it'd get leaked instead of the destructor running during the
-            // evaluation of `X` (if at all allowed by CTFE).
-            //
-            // However, `const Y: ... = g(&f());`, like `let y = g(&f());`,
-            // would *not* let the `f()` temporary escape into an outer scope
-            // (i.e., `'static`), which means that after `g` returns, it drops,
-            // and all the associated destruction scope rules apply.
-            self.cx.var_parent = None;
-            resolve_local(self, None, Some(body.value));
-        }
+        f(self);
 
         // Restore context we had at the start.
         self.expr_and_pat_count = outer_ec;
         self.cx = outer_cx;
         self.terminating_scopes = outer_ts;
         self.pessimistic_yield = outer_pessimistic_yield;
     }
+}
+
+impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
+    fn visit_block(&mut self, b: &'tcx Block<'tcx>) {
+        resolve_block(self, b);
+    }
+
+    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
+        let body_id = body.id();
+        let owner_id = self.tcx.hir().body_owner_def_id(body_id);
+
+        debug!(
+            "visit_body(id={:?}, span={:?}, body.id={:?}, cx.parent={:?})",
+            owner_id,
+            self.tcx.sess.source_map().span_to_diagnostic_string(body.value.span),
+            body_id,
+            self.cx.parent
+        );
+
+        self.enter_body(body.value.hir_id, |this| {
+            if this.tcx.hir().body_owner_kind(owner_id).is_fn_or_closure() {
+                // The arguments and `self` are parented to the fn.
+                this.cx.var_parent = this.cx.parent.take();
+                for param in body.params {
+                    this.visit_pat(param.pat);
+                }
+
+                // The body of the every fn is a root scope.
+                this.cx.parent = this.cx.var_parent;
+                this.visit_expr(body.value)
+            } else {
+                // Only functions have an outer terminating (drop) scope, while
+                // temporaries in constant initializers may be 'static, but only
+                // according to rvalue lifetime semantics, using the same
+                // syntactical rules used for let initializers.
+                //
+                // e.g., in `let x = &f();`, the temporary holding the result from
+                // the `f()` call lives for the entirety of the surrounding block.
+                //
+                // Similarly, `const X: ... = &f();` would have the result of `f()`
+                // live for `'static`, implying (if Drop restrictions on constants
+                // ever get lifted) that the value *could* have a destructor, but
+                // it'd get leaked instead of the destructor running during the
+                // evaluation of `X` (if at all allowed by CTFE).
+                //
+                // However, `const Y: ... = g(&f());`, like `let y = g(&f());`,
+                // would *not* let the `f()` temporary escape into an outer scope
+                // (i.e., `'static`), which means that after `g` returns, it drops,
+                // and all the associated destruction scope rules apply.
+                this.cx.var_parent = None;
+                resolve_local(this, None, Some(body.value));
+            }
+        })
+    }
 
     fn visit_arm(&mut self, a: &'tcx Arm<'tcx>) {
         resolve_arm(self, a);

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::ConstBlock(_)
-        | Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => {
-            Some(tcx.typeck_root_def_id(def_id.to_def_id()))
-        }
+        Node::Expr(&hir::Expr {
+            kind: hir::ExprKind::Closure { .. } | hir::ExprKind::ConstBlock { .. },
+            ..
+        }) => Some(tcx.typeck_root_def_id(def_id.to_def_id())),
         Node::Item(item) => match item.kind {
             ItemKind::OpaqueTy(&hir::OpaqueTy {
                 origin:
@@ -414,7 +414,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
     }
 
     // provide junk type parameter defs for const blocks.
-    if let Node::ConstBlock(_) = node {
+    if let Node::Expr(Expr { kind: ExprKind::ConstBlock(..), .. }) = node {
         own_params.push(ty::GenericParamDef {
             index: next_index(),
             name: Symbol::intern("<const_ty>"),

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -484,8 +484,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<Ty
         }
 
         Node::AnonConst(_) => anon_const_type_of(tcx, def_id),
-
-        Node::ConstBlock(_) => {
+        Node::Expr(&Expr { kind: ExprKind::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

@@ -191,10 +191,6 @@ 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();
-
     // 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
@@ -206,6 +202,10 @@ 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();
+
     tcx.ensure().check_unused_traits(());
 }
 

compiler/rustc_hir_pretty/src/lib.rs

@@ -84,7 +84,6 @@ 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 +1048,10 @@ impl<'a> State<'a> {
         self.end()
     }
 
-    fn print_inline_const(&mut self, constant: &hir::ConstBlock) {
+    fn print_inline_const(&mut self, constant: &hir::Expr<'_>) {
         self.ibox(INDENT_UNIT);
         self.word_space("const");
-        self.ann.nested(self, Nested::Body(constant.body));
+        self.print_expr(constant);
         self.end()
     }