Auto merge of rust-lang#88946 - cuviper:beta-next, r=Mark-Simulacrum

[beta] backports

- rustdoc: Fix ICE with `doc(hidden)` on tuple variant fields rust-lang#88639
- Fix 2021 `dyn` suggestion that used code as label rust-lang#88657
- Workaround blink/chromium grid layout limitation of 1000 rows rust-lang#88776
- Change scope of temporaries in match guards rust-lang#88678
- Add a regression test for rust-lang#88649 rust-lang#88691
- Revert anon union parsing rust-lang#88775
- Disable validate_maintainers. rust-lang#88977

Also drop stage0 rustfmt, because that's only supposed to be used on master.

r? `@Mark-Simulacrum`

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

@@ -749,10 +749,7 @@ 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

@@ -1290,15 +1290,6 @@ 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 {
@@ -1067,7 +1001,6 @@ 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)
     }
 
@@ -1082,7 +1015,6 @@ 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_feature/src/active.rs

@@ -639,9 +639,6 @@ 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_mir_build/src/build/expr/into.rs

@@ -68,7 +68,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                                     let then_blk = unpack!(this.then_else_break(
                                         block,
                                         &this.thir[cond],
-                                        condition_scope,
+                                        Some(condition_scope),
                                         condition_scope,
                                         then_expr.span,
                                     ));

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -39,7 +39,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         &mut self,
         mut block: BasicBlock,
         expr: &Expr<'tcx>,
-        temp_scope: region::Scope,
+        temp_scope_override: Option<region::Scope>,
         break_scope: region::Scope,
         variable_scope_span: Span,
     ) -> BlockAnd<()> {
@@ -53,7 +53,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     this.then_else_break(
                         block,
                         &this.thir[value],
-                        temp_scope,
+                        temp_scope_override,
                         break_scope,
                         variable_scope_span,
                     )
@@ -63,6 +63,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 this.lower_let_expr(block, &this.thir[expr], pat, break_scope, variable_scope_span)
             }
             _ => {
+                let temp_scope = temp_scope_override.unwrap_or_else(|| this.local_scope());
                 let mutability = Mutability::Mut;
                 let place =
                     unpack!(block = this.as_temp(block, Some(temp_scope), expr, mutability));
@@ -1948,7 +1949,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             }
 
             let arm_span = arm_span.unwrap();
-            let arm_scope = self.local_scope();
             let match_scope = match_scope.unwrap();
             let mut guard_span = rustc_span::DUMMY_SP;
 
@@ -1957,7 +1957,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     Guard::If(e) => {
                         let e = &this.thir[e];
                         guard_span = e.span;
-                        this.then_else_break(block, e, arm_scope, match_scope, arm_span)
+                        this.then_else_break(block, e, None, match_scope, arm_span)
                     }
                     Guard::IfLet(ref pat, scrutinee) => {
                         let s = &this.thir[scrutinee];

compiler/rustc_parse/src/parser/item.rs

@@ -1234,7 +1234,7 @@ impl<'a> Parser<'a> {
         Ok((class_name, ItemKind::Union(vdata, generics)))
     }
 
-    pub(super) fn parse_record_struct_body(
+    fn parse_record_struct_body(
         &mut self,
         adt_ty: &str,
     ) -> PResult<'a, (Vec<FieldDef>, /* recovered */ bool)> {
@@ -1468,28 +1468,22 @@ impl<'a> Parser<'a> {
     fn parse_field_ident(&mut self, adt_ty: &str, lo: Span) -> PResult<'a, Ident> {
         let (ident, is_raw) = self.ident_or_err()?;
         if !is_raw && ident.is_reserved() {
-            if ident.name == kw::Underscore {
-                self.sess.gated_spans.gate(sym::unnamed_fields, lo);
+            let err = if self.check_fn_front_matter(false) {
+                // We use `parse_fn` to get a span for the function
+                if let Err(mut db) = self.parse_fn(&mut Vec::new(), |_| true, lo) {
+                    db.delay_as_bug();
+                }
+                let mut err = self.struct_span_err(
+                    lo.to(self.prev_token.span),
+                    &format!("functions are not allowed in {} definitions", adt_ty),
+                );
+                err.help("unlike in C++, Java, and C#, functions are declared in `impl` blocks");
+                err.help("see https://doc.rust-lang.org/book/ch05-03-method-syntax.html for more information");
+                err
             } else {
-                let err = if self.check_fn_front_matter(false) {
-                    // We use `parse_fn` to get a span for the function
-                    if let Err(mut db) = self.parse_fn(&mut Vec::new(), |_| true, lo) {
-                        db.delay_as_bug();
-                    }
-                    let mut err = self.struct_span_err(
-                        lo.to(self.prev_token.span),
-                        &format!("functions are not allowed in {} definitions", adt_ty),
-                    );
-                    err.help(
-                        "unlike in C++, Java, and C#, functions are declared in `impl` blocks",
-                    );
-                    err.help("see https://doc.rust-lang.org/book/ch05-03-method-syntax.html for more information");
-                    err
-                } else {
-                    self.expected_ident_found()
-                };
-                return Err(err);
-            }
+                self.expected_ident_found()
+            };
+            return Err(err);
         }
         self.bump();
         Ok(ident)

compiler/rustc_parse/src/parser/ty.rs

@@ -226,19 +226,6 @@ impl<'a> Parser<'a> {
             }
         } else if self.eat_keyword(kw::Impl) {
             self.parse_impl_ty(&mut impl_dyn_multi)?
-        } else if self.token.is_keyword(kw::Union)
-            && self.look_ahead(1, |t| t == &token::OpenDelim(token::Brace))
-        {
-            self.bump();
-            let (fields, recovered) = self.parse_record_struct_body("union")?;
-            let span = lo.to(self.prev_token.span);
-            self.sess.gated_spans.gate(sym::unnamed_fields, span);
-            TyKind::AnonymousUnion(fields, recovered)
-        } else if self.eat_keyword(kw::Struct) {
-            let (fields, recovered) = self.parse_record_struct_body("struct")?;
-            let span = lo.to(self.prev_token.span);
-            self.sess.gated_spans.gate(sym::unnamed_fields, span);
-            TyKind::AnonymousStruct(fields, recovered)
         } else if self.is_explicit_dyn_type() {
             self.parse_dyn_ty(&mut impl_dyn_multi)?
         } else if self.eat_lt() {

compiler/rustc_span/src/symbol.rs

@@ -1358,7 +1358,6 @@ symbols! {
         unix,
         unlikely,
         unmarked_api,
-        unnamed_fields,
         unpin,
         unreachable,
         unreachable_code,

compiler/rustc_typeck/src/check/fn_ctxt/_impl.rs

@@ -945,7 +945,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     Ok(s) if s.starts_with('<') => sugg,
                     _ => format!("<{}>", sugg),
                 };
-                let replace = String::from("use `dyn`");
+                let sugg_label = "use `dyn`";
                 if self.sess().edition() >= Edition::Edition2021 {
                     let mut err = rustc_errors::struct_span_err!(
                         self.sess(),
@@ -956,8 +956,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     );
                     err.span_suggestion(
                         self_ty.span,
-                        &sugg,
-                        replace,
+                        sugg_label,
+                        sugg,
                         Applicability::MachineApplicable,
                     )
                     .emit();
@@ -968,7 +968,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         self_ty.span,
                         |lint| {
                             let mut db = lint.build(msg);
-                            db.span_suggestion(self_ty.span, &replace, sugg, app);
+                            db.span_suggestion(self_ty.span, sugg_label, sugg, app);
                             db.emit()
                         },
                     );