Rollup of 6 pull requests

compiler/rustc_ast/src/ast.rs

@@ -1902,10 +1902,6 @@ pub enum TyKind {
     Never,
     /// A tuple (`(A, B, C, D,...)`).
     Tup(Vec<P<Ty>>),
-    /// An anonymous struct type i.e. `struct { foo: Type }`
-    AnonymousStruct(Vec<FieldDef>, bool),
-    /// An anonymous union type i.e. `union { bar: Type }`
-    AnonymousUnion(Vec<FieldDef>, bool),
     /// A path (`module::module::...::Type`), optionally
     /// "qualified", e.g., `<Vec<T> as SomeTrait>::SomeType`.
     ///

compiler/rustc_ast/src/mut_visit.rs

@@ -484,9 +484,6 @@ pub fn noop_visit_ty<T: MutVisitor>(ty: &mut P<Ty>, vis: &mut T) {
             visit_vec(bounds, |bound| vis.visit_param_bound(bound));
         }
         TyKind::MacCall(mac) => vis.visit_mac_call(mac),
-        TyKind::AnonymousStruct(fields, ..) | TyKind::AnonymousUnion(fields, ..) => {
-            fields.flat_map_in_place(|field| vis.flat_map_field_def(field));
-        }
     }
     vis.visit_span(span);
     visit_lazy_tts(tokens, vis);

compiler/rustc_ast/src/visit.rs

@@ -407,9 +407,6 @@ pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
         TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
         TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
         TyKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
-        TyKind::AnonymousStruct(ref fields, ..) | TyKind::AnonymousUnion(ref fields, ..) => {
-            walk_list!(visitor, visit_field_def, fields)
-        }
         TyKind::Never | TyKind::CVarArgs => {}
     }
 }

compiler/rustc_ast_lowering/src/item.rs

@@ -748,10 +748,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
-    pub(super) fn lower_field_def(
-        &mut self,
-        (index, f): (usize, &FieldDef),
-    ) -> hir::FieldDef<'hir> {
+    fn lower_field_def(&mut self, (index, f): (usize, &FieldDef)) -> hir::FieldDef<'hir> {
         let ty = if let TyKind::Path(ref qself, ref path) = f.ty.kind {
             let t = self.lower_path_ty(
                 &f.ty,

compiler/rustc_ast_lowering/src/lib.rs

@@ -1301,15 +1301,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let kind = match t.kind {
             TyKind::Infer => hir::TyKind::Infer,
             TyKind::Err => hir::TyKind::Err,
-            // FIXME(unnamed_fields): IMPLEMENTATION IN PROGRESS
-            TyKind::AnonymousStruct(ref _fields, _recovered) => {
-                self.sess.struct_span_err(t.span, "anonymous structs are unimplemented").emit();
-                hir::TyKind::Err
-            }
-            TyKind::AnonymousUnion(ref _fields, _recovered) => {
-                self.sess.struct_span_err(t.span, "anonymous unions are unimplemented").emit();
-                hir::TyKind::Err
-            }
             TyKind::Slice(ref ty) => hir::TyKind::Slice(self.lower_ty(ty, itctx)),
             TyKind::Ptr(ref mt) => hir::TyKind::Ptr(self.lower_mt(mt, itctx)),
             TyKind::Rptr(ref region, ref mt) => {

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -193,19 +193,13 @@ impl<'a> AstValidator<'a> {
                     }
                 }
             }
-            TyKind::AnonymousStruct(ref fields, ..) | TyKind::AnonymousUnion(ref fields, ..) => {
-                self.with_banned_assoc_ty_bound(|this| {
-                    walk_list!(this, visit_struct_field_def, fields)
-                });
-            }
             _ => visit::walk_ty(self, t),
         }
     }
 
     fn visit_struct_field_def(&mut self, field: &'a FieldDef) {
         if let Some(ident) = field.ident {
             if ident.name == kw::Underscore {
-                self.check_anonymous_field(field);
                 self.visit_vis(&field.vis);
                 self.visit_ident(ident);
                 self.visit_ty_common(&field.ty);
@@ -251,66 +245,6 @@ impl<'a> AstValidator<'a> {
         err.emit();
     }
 
-    fn check_anonymous_field(&self, field: &FieldDef) {
-        let FieldDef { ty, .. } = field;
-        match &ty.kind {
-            TyKind::AnonymousStruct(..) | TyKind::AnonymousUnion(..) => {
-                // We already checked for `kw::Underscore` before calling this function,
-                // so skip the check
-            }
-            TyKind::Path(..) => {
-                // If the anonymous field contains a Path as type, we can't determine
-                // if the path is a valid struct or union, so skip the check
-            }
-            _ => {
-                let msg = "unnamed fields can only have struct or union types";
-                let label = "not a struct or union";
-                self.err_handler()
-                    .struct_span_err(field.span, msg)
-                    .span_label(ty.span, label)
-                    .emit();
-            }
-        }
-    }
-
-    fn deny_anonymous_struct(&self, ty: &Ty) {
-        match &ty.kind {
-            TyKind::AnonymousStruct(..) => {
-                self.err_handler()
-                    .struct_span_err(
-                        ty.span,
-                        "anonymous structs are not allowed outside of unnamed struct or union fields",
-                    )
-                    .span_label(ty.span, "anonymous struct declared here")
-                    .emit();
-            }
-            TyKind::AnonymousUnion(..) => {
-                self.err_handler()
-                    .struct_span_err(
-                        ty.span,
-                        "anonymous unions are not allowed outside of unnamed struct or union fields",
-                    )
-                    .span_label(ty.span, "anonymous union declared here")
-                    .emit();
-            }
-            _ => {}
-        }
-    }
-
-    fn deny_anonymous_field(&self, field: &FieldDef) {
-        if let Some(ident) = field.ident {
-            if ident.name == kw::Underscore {
-                self.err_handler()
-                    .struct_span_err(
-                        field.span,
-                        "anonymous fields are not allowed outside of structs or unions",
-                    )
-                    .span_label(ident.span, "anonymous field declared here")
-                    .emit()
-            }
-        }
-    }
-
     fn check_decl_no_pat(decl: &FnDecl, mut report_err: impl FnMut(Span, Option<Ident>, bool)) {
         for Param { pat, .. } in &decl.inputs {
             match pat.kind {
@@ -1081,7 +1015,6 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
 
     fn visit_ty(&mut self, ty: &'a Ty) {
         self.visit_ty_common(ty);
-        self.deny_anonymous_struct(ty);
         self.walk_ty(ty)
     }
 
@@ -1096,7 +1029,6 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
     }
 
     fn visit_field_def(&mut self, s: &'a FieldDef) {
-        self.deny_anonymous_field(s);
         visit::walk_field_def(self, s)
     }
 

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -668,7 +668,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session) {
         // involved, so we only emit errors where there are no other parsing errors.
         gate_all!(destructuring_assignment, "destructuring assignments are unstable");
     }
-    gate_all!(unnamed_fields, "unnamed fields are not yet fully implemented");
 
     // All uses of `gate_all!` below this point were added in #65742,
     // and subsequently disabled (with the non-early gating readded).

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -985,14 +985,6 @@ impl<'a> State<'a> {
                 }
                 self.pclose();
             }
-            ast::TyKind::AnonymousStruct(ref fields, ..) => {
-                self.head("struct");
-                self.print_record_struct_body(&fields, ty.span);
-            }
-            ast::TyKind::AnonymousUnion(ref fields, ..) => {
-                self.head("union");
-                self.print_record_struct_body(&fields, ty.span);
-            }
             ast::TyKind::Paren(ref typ) => {
                 self.popen();
                 self.print_type(typ);
@@ -1413,7 +1405,12 @@ impl<'a> State<'a> {
         }
     }
 
-    crate fn print_record_struct_body(&mut self, fields: &[ast::FieldDef], span: rustc_span::Span) {
+    crate fn print_record_struct_body(
+        &mut self,
+        fields: &Vec<ast::FieldDef>,
+        span: rustc_span::Span,
+    ) {
+        self.nbsp();
         self.bopen();
         self.hardbreak_if_not_bol();
 
@@ -1462,7 +1459,6 @@ impl<'a> State<'a> {
             }
             ast::VariantData::Struct(ref fields, ..) => {
                 self.print_where_clause(&generics.where_clause);
-                self.nbsp();
                 self.print_record_struct_body(fields, span);
             }
         }

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -3,9 +3,11 @@ use rustc_index::vec::IndexVec;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir;
 use rustc_middle::ty;
+use rustc_middle::ty::layout::LayoutOf;
 use rustc_session::config::DebugInfo;
 use rustc_span::symbol::{kw, Symbol};
 use rustc_span::{BytePos, Span};
+use rustc_target::abi::Abi;
 use rustc_target::abi::Size;
 
 use super::operand::{OperandRef, OperandValue};
@@ -368,21 +370,14 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         {
                             let arg_index = place.local.index() - 1;
                             if target_is_msvc {
-                                // Rust compiler decomposes every &str or slice argument into two components:
-                                // a pointer to the memory address where the data is stored and a usize representing
-                                // the length of the str (or slice). These components will later be used to reconstruct
-                                // the original argument inside the body of the function that owns it (see the
-                                // definition of debug_introduce_local for more details).
-                                //
-                                // Since the original argument is declared inside a function rather than being passed
-                                // in as an argument, it must be marked as a LocalVariable for MSVC debuggers to visualize
-                                // its data correctly. (See issue #81894 for an in-depth description of the problem).
-                                match *var_ty.kind() {
-                                    ty::Ref(_, inner_type, _) => match *inner_type.kind() {
-                                        ty::Slice(_) | ty::Str => VariableKind::LocalVariable,
-                                        _ => VariableKind::ArgumentVariable(arg_index + 1),
-                                    },
-                                    _ => VariableKind::ArgumentVariable(arg_index + 1),
+                                // ScalarPair parameters are spilled to the stack so they need to
+                                // be marked as a `LocalVariable` for MSVC debuggers to visualize
+                                // their data correctly. (See #81894 & #88625)
+                                let var_ty_layout = self.cx.layout_of(var_ty);
+                                if let Abi::ScalarPair(_, _) = var_ty_layout.abi {
+                                    VariableKind::LocalVariable
+                                } else {
+                                    VariableKind::ArgumentVariable(arg_index + 1)
                                 }
                             } else {
                                 // FIXME(eddyb) shouldn't `ArgumentVariable` indices be

compiler/rustc_codegen_ssa/src/mir/mod.rs

@@ -129,6 +129,7 @@ impl<'a, 'tcx, V: CodegenObject> LocalRef<'tcx, V> {
 
 ///////////////////////////////////////////////////////////////////////////
 
+#[instrument(level = "debug", skip(cx))]
 pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     cx: &'a Bx::CodegenCx,
     instance: Instance<'tcx>,

compiler/rustc_data_structures/src/graph/iterate/mod.rs

@@ -83,8 +83,58 @@ impl<G> DepthFirstSearch<'graph, G>
 where
     G: ?Sized + DirectedGraph + WithNumNodes + WithSuccessors,
 {
-    pub fn new(graph: &'graph G, start_node: G::Node) -> Self {
-        Self { graph, stack: vec![start_node], visited: BitSet::new_empty(graph.num_nodes()) }
+    pub fn new(graph: &'graph G) -> Self {
+        Self { graph, stack: vec![], visited: BitSet::new_empty(graph.num_nodes()) }
+    }
+
+    /// Version of `push_start_node` that is convenient for chained
+    /// use.
+    pub fn with_start_node(mut self, start_node: G::Node) -> Self {
+        self.push_start_node(start_node);
+        self
+    }
+
+    /// Pushes another start node onto the stack. If the node
+    /// has not already been visited, then you will be able to
+    /// walk its successors (and so forth) after the current
+    /// contents of the stack are drained. If multiple start nodes
+    /// are added into the walk, then their mutual successors
+    /// will all be walked. You can use this method once the
+    /// iterator has been completely drained to add additional
+    /// start nodes.
+    pub fn push_start_node(&mut self, start_node: G::Node) {
+        if self.visited.insert(start_node) {
+            self.stack.push(start_node);
+        }
+    }
+
+    /// Searches all nodes reachable from the current start nodes.
+    /// This is equivalent to just invoke `next` repeatedly until
+    /// you get a `None` result.
+    pub fn complete_search(&mut self) {
+        while let Some(_) = self.next() {}
+    }
+
+    /// Returns true if node has been visited thus far.
+    /// A node is considered "visited" once it is pushed
+    /// onto the internal stack; it may not yet have been yielded
+    /// from the iterator. This method is best used after
+    /// the iterator is completely drained.
+    pub fn visited(&self, node: G::Node) -> bool {
+        self.visited.contains(node)
+    }
+}
+
+impl<G> std::fmt::Debug for DepthFirstSearch<'_, G>
+where
+    G: ?Sized + DirectedGraph + WithNumNodes + WithSuccessors,
+{
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut f = fmt.debug_set();
+        for n in self.visited.iter() {
+            f.entry(&n);
+        }
+        f.finish()
     }
 }
 

compiler/rustc_data_structures/src/graph/iterate/tests.rs

@@ -20,3 +20,19 @@ fn is_cyclic() {
     assert!(!is_cyclic(&diamond_acyclic));
     assert!(is_cyclic(&diamond_cyclic));
 }
+
+#[test]
+fn dfs() {
+    let graph = TestGraph::new(0, &[(0, 1), (0, 2), (1, 3), (2, 3), (3, 0)]);
+
+    let result: Vec<usize> = DepthFirstSearch::new(&graph).with_start_node(0).collect();
+    assert_eq!(result, vec![0, 2, 3, 1]);
+}
+
+#[test]
+fn dfs_debug() {
+    let graph = TestGraph::new(0, &[(0, 1), (0, 2), (1, 3), (2, 3), (3, 0)]);
+    let mut dfs = DepthFirstSearch::new(&graph).with_start_node(0);
+    dfs.complete_search();
+    assert_eq!(format!("{{0, 1, 2, 3}}"), format!("{:?}", dfs));
+}

compiler/rustc_data_structures/src/graph/mod.rs

@@ -32,7 +32,7 @@ where
     where
         Self: WithNumNodes,
     {
-        iterate::DepthFirstSearch::new(self, from)
+        iterate::DepthFirstSearch::new(self).with_start_node(from)
     }
 }
 

compiler/rustc_data_structures/src/lib.rs

@@ -21,6 +21,7 @@
 #![feature(iter_map_while)]
 #![feature(maybe_uninit_uninit_array)]
 #![feature(min_specialization)]
+#![feature(never_type)]
 #![feature(type_alias_impl_trait)]
 #![feature(new_uninit)]
 #![feature(nll)]

compiler/rustc_data_structures/src/stable_hasher.rs

@@ -209,6 +209,12 @@ impl_stable_hash_via_hash!(i128);
 impl_stable_hash_via_hash!(char);
 impl_stable_hash_via_hash!(());
 
+impl<CTX> HashStable<CTX> for ! {
+    fn hash_stable(&self, _ctx: &mut CTX, _hasher: &mut StableHasher) {
+        unreachable!()
+    }
+}
+
 impl<CTX> HashStable<CTX> for ::std::num::NonZeroU32 {
     fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
         self.get().hash_stable(ctx, hasher)

compiler/rustc_feature/src/active.rs

@@ -638,9 +638,6 @@ declare_features! (
     /// Allows specifying the as-needed link modifier
     (active, native_link_modifiers_as_needed, "1.53.0", Some(81490), None),
 
-    /// Allows unnamed fields of struct and union type
-    (incomplete, unnamed_fields, "1.53.0", Some(49804), None),
-
     /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns.
     (active, more_qualified_paths, "1.54.0", Some(86935), None),
 

compiler/rustc_hir/src/def.rs

@@ -598,6 +598,11 @@ impl<Id> Res<Id> {
         }
     }
 
+    #[track_caller]
+    pub fn expect_non_local<OtherId>(self) -> Res<OtherId> {
+        self.map_id(|_| panic!("unexpected `Res::Local`"))
+    }
+
     pub fn macro_kind(self) -> Option<MacroKind> {
         match self {
             Res::Def(DefKind::Macro(kind), _) => Some(kind),