Merge from rustc

Author: The Miri Cronjob Bot

.github/workflows/ci.yml

@@ -154,9 +154,12 @@ jobs:
 
       - name: checkout submodules
         run: src/ci/scripts/checkout-submodules.sh
-
-      - name: install MSYS2
-        run: src/ci/scripts/install-msys2.sh
+      
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+        if: runner.environment == 'github-hosted'
 
       - name: install MinGW
         run: src/ci/scripts/install-mingw.sh

Cargo.lock

@@ -4082,6 +4082,7 @@ dependencies = [
  "rustc_feature",
  "rustc_fluent_macro",
  "rustc_hir",
+ "rustc_hir_pretty",
  "rustc_index",
  "rustc_infer",
  "rustc_macros",

compiler/rustc_abi/src/layout.rs

@@ -970,7 +970,7 @@ fn univariant<
     let mut align = if pack.is_some() { dl.i8_align } else { dl.aggregate_align };
     let mut max_repr_align = repr.align;
     let mut inverse_memory_index: IndexVec<u32, FieldIdx> = fields.indices().collect();
-    let optimize = !repr.inhibit_struct_field_reordering_opt();
+    let optimize = !repr.inhibit_struct_field_reordering();
     if optimize && fields.len() > 1 {
         let end = if let StructKind::MaybeUnsized = kind { fields.len() - 1 } else { fields.len() };
         let optimizing = &mut inverse_memory_index.raw[..end];
@@ -1007,13 +1007,15 @@ fn univariant<
             // Calculates a sort key to group fields by their alignment or possibly some
             // size-derived pseudo-alignment.
             let alignment_group_key = |layout: &F| {
+                // The two branches here return values that cannot be meaningfully compared with
+                // each other. However, we know that consistently for all executions of
+                // `alignment_group_key`, one or the other branch will be taken, so this is okay.
                 if let Some(pack) = pack {
                     // Return the packed alignment in bytes.
                     layout.align.abi.min(pack).bytes()
                 } else {
-                    // Returns `log2(effective-align)`. This is ok since `pack` applies to all
-                    // fields equally. The calculation assumes that size is an integer multiple of
-                    // align, except for ZSTs.
+                    // Returns `log2(effective-align)`. The calculation assumes that size is an
+                    // integer multiple of align, except for ZSTs.
                     let align = layout.align.abi.bytes();
                     let size = layout.size.bytes();
                     let niche_size = layout.largest_niche.map(|n| n.available(dl)).unwrap_or(0);

compiler/rustc_abi/src/lib.rs

@@ -137,23 +137,16 @@ impl ReprOptions {
         self.c() || self.int.is_some()
     }
 
-    /// Returns `true` if this `#[repr()]` should inhibit struct field reordering
-    /// optimizations, such as with `repr(C)`, `repr(packed(1))`, or `repr(<int>)`.
-    pub fn inhibit_struct_field_reordering_opt(&self) -> bool {
-        if let Some(pack) = self.pack {
-            if pack.bytes() == 1 {
-                return true;
-            }
-        }
-
+    /// Returns `true` if this `#[repr()]` guarantees a fixed field order,
+    /// e.g. `repr(C)` or `repr(<int>)`.
+    pub fn inhibit_struct_field_reordering(&self) -> bool {
         self.flags.intersects(ReprFlags::IS_UNOPTIMISABLE) || self.int.is_some()
     }
 
     /// Returns `true` if this type is valid for reordering and `-Z randomize-layout`
     /// was enabled for its declaration crate.
     pub fn can_randomize_type_layout(&self) -> bool {
-        !self.inhibit_struct_field_reordering_opt()
-            && self.flags.contains(ReprFlags::RANDOMIZE_LAYOUT)
+        !self.inhibit_struct_field_reordering() && self.flags.contains(ReprFlags::RANDOMIZE_LAYOUT)
     }
 
     /// Returns `true` if this `#[repr()]` should inhibit union ABI optimisations.

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

@@ -852,10 +852,10 @@ pub fn walk_assoc_item<'a, V: Visitor<'a>>(
     ctxt: AssocCtxt,
 ) -> V::Result {
     let &Item { id: _, span: _, ident, ref vis, ref attrs, ref kind, tokens: _ } = item;
-    walk_list!(visitor, visit_attribute, attrs);
     try_visit!(visitor.visit_vis(vis));
     try_visit!(visitor.visit_ident(ident));
     try_visit!(kind.walk(item, ctxt, visitor));
+    walk_list!(visitor, visit_attribute, attrs);
     V::Result::output()
 }
 
@@ -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

@@ -75,12 +75,8 @@ 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)
+                    self.has_inline_consts = true;
+                    hir::ExprKind::ConstBlock(self.lower_expr(c))
                 }
                 ExprKind::Repeat(expr, count) => {
                     let expr = self.lower_expr(expr);

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_lowering/src/lib.rs

@@ -96,6 +96,8 @@ struct LoweringContext<'a, 'hir> {
 
     /// Bodies inside the owner being lowered.
     bodies: Vec<(hir::ItemLocalId, &'hir hir::Body<'hir>)>,
+    /// Whether there were inline consts that typeck will split out into bodies
+    has_inline_consts: bool,
     /// Attributes inside the owner being lowered.
     attrs: SortedMap<hir::ItemLocalId, &'hir [Attribute]>,
     /// Collect items that were created by lowering the current owner.
@@ -158,6 +160,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             item_local_id_counter: hir::ItemLocalId::ZERO,
             node_id_to_local_id: Default::default(),
             trait_map: Default::default(),
+            has_inline_consts: false,
 
             // Lowering state.
             catch_scope: None,
@@ -567,6 +570,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         let current_attrs = std::mem::take(&mut self.attrs);
         let current_bodies = std::mem::take(&mut self.bodies);
+        let current_has_inline_consts = std::mem::take(&mut self.has_inline_consts);
         let current_node_ids = std::mem::take(&mut self.node_id_to_local_id);
         let current_trait_map = std::mem::take(&mut self.trait_map);
         let current_owner =
@@ -593,6 +597,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         self.attrs = current_attrs;
         self.bodies = current_bodies;
+        self.has_inline_consts = current_has_inline_consts;
         self.node_id_to_local_id = current_node_ids;
         self.trait_map = current_trait_map;
         self.current_hir_id_owner = current_owner;
@@ -629,6 +634,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let attrs = std::mem::take(&mut self.attrs);
         let mut bodies = std::mem::take(&mut self.bodies);
         let trait_map = std::mem::take(&mut self.trait_map);
+        let has_inline_consts = std::mem::take(&mut self.has_inline_consts);
 
         #[cfg(debug_assertions)]
         for (id, attrs) in attrs.iter() {
@@ -646,7 +652,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             self.tcx.hash_owner_nodes(node, &bodies, &attrs);
         let num_nodes = self.item_local_id_counter.as_usize();
         let (nodes, parenting) = index::index_hir(self.tcx, node, &bodies, num_nodes);
-        let nodes = hir::OwnerNodes { opt_hash_including_bodies, nodes, bodies };
+        let nodes = hir::OwnerNodes { opt_hash_including_bodies, nodes, bodies, has_inline_consts };
         let attrs = hir::AttributeMap { map: attrs, opt_hash: attrs_hash };
 
         self.arena.alloc(hir::OwnerInfo { nodes, parenting, attrs, trait_map })