Rollup merge of #119145 - aDotInTheVoid:variantdata-struct-struct, r=compiler-errors

Give `VariantData::Struct`  named fields, to clairfy `recovered`.

Implements https://github.com/rust-lang/rust/pull/119121#discussion_r1431467066. Supersedes #119121

This way, it's clear what the bool fields means, instead of having to find where it's generated. Changes both ast and hir.

r? `@compiler-errors`

compiler/rustc_ast/src/ast.rs

@@ -2788,7 +2788,11 @@ pub enum VariantData {
     /// Struct variant.
     ///
     /// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
-    Struct(ThinVec<FieldDef>, bool),
+    Struct {
+        fields: ThinVec<FieldDef>,
+        // FIXME: investigate making this a `Option<ErrorGuaranteed>`
+        recovered: bool,
+    },
     /// Tuple variant.
     ///
     /// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
@@ -2803,7 +2807,7 @@ impl VariantData {
     /// Return the fields of this variant.
     pub fn fields(&self) -> &[FieldDef] {
         match self {
-            VariantData::Struct(fields, ..) | VariantData::Tuple(fields, _) => fields,
+            VariantData::Struct { fields, .. } | VariantData::Tuple(fields, _) => fields,
             _ => &[],
         }
     }
@@ -2811,7 +2815,7 @@ impl VariantData {
     /// Return the `NodeId` of this variant's constructor, if it has one.
     pub fn ctor_node_id(&self) -> Option<NodeId> {
         match *self {
-            VariantData::Struct(..) => None,
+            VariantData::Struct { .. } => None,
             VariantData::Tuple(_, id) | VariantData::Unit(id) => Some(id),
         }
     }

compiler/rustc_ast/src/mut_visit.rs

@@ -976,7 +976,7 @@ pub fn noop_visit_where_predicate<T: MutVisitor>(pred: &mut WherePredicate, vis:
 
 pub fn noop_visit_variant_data<T: MutVisitor>(vdata: &mut VariantData, vis: &mut T) {
     match vdata {
-        VariantData::Struct(fields, ..) => {
+        VariantData::Struct { fields, .. } => {
             fields.flat_map_in_place(|field| vis.flat_map_field_def(field));
         }
         VariantData::Tuple(fields, id) => {

compiler/rustc_ast_lowering/src/item.rs

@@ -661,11 +661,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
         vdata: &VariantData,
     ) -> hir::VariantData<'hir> {
         match vdata {
-            VariantData::Struct(fields, recovered) => hir::VariantData::Struct(
+            VariantData::Struct { fields, recovered } => hir::VariantData::Struct {
-                self.arena
+                fields: self
+                    .arena
                     .alloc_from_iter(fields.iter().enumerate().map(|f| self.lower_field_def(f))),
-                *recovered,
+                recovered: *recovered,
-            ),
+            },
             VariantData::Tuple(fields, id) => {
                 let ctor_id = self.lower_node_id(*id);
                 self.alias_attrs(ctor_id, parent_id);

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1000,7 +1000,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 }
             }
             ItemKind::Struct(vdata, generics) => match vdata {
-                VariantData::Struct(fields, ..) => {
+                VariantData::Struct { fields, .. } => {
                     self.visit_vis(&item.vis);
                     self.visit_ident(item.ident);
                     self.visit_generics(generics);
@@ -1016,7 +1016,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                     self.dcx().emit_err(errors::FieldlessUnion { span: item.span });
                 }
                 match vdata {
-                    VariantData::Struct(fields, ..) => {
+                    VariantData::Struct { fields, .. } => {
                         self.visit_vis(&item.vis);
                         self.visit_ident(item.ident);
                         self.visit_generics(generics);

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -500,7 +500,7 @@ impl<'a> State<'a> {
                 self.end();
                 self.end(); // Close the outer-box.
             }
-            ast::VariantData::Struct(fields, ..) => {
+            ast::VariantData::Struct { fields, .. } => {
                 self.print_where_clause(&generics.where_clause);
                 self.print_record_struct_body(fields, span);
             }

compiler/rustc_builtin_macros/src/deriving/clone.rs

@@ -188,7 +188,7 @@ fn cs_clone(
     }
 
     let expr = match *vdata {
-        VariantData::Struct(..) => {
+        VariantData::Struct { .. } => {
             let fields = all_fields
                 .iter()
                 .map(|field| {

compiler/rustc_builtin_macros/src/deriving/debug.rs

@@ -71,7 +71,7 @@ fn show_substructure(cx: &mut ExtCtxt<'_>, span: Span, substr: &Substructure<'_>
             (false, 0)
         }
         ast::VariantData::Tuple(..) => (false, 1),
-        ast::VariantData::Struct(..) => (true, 2),
+        ast::VariantData::Struct { .. } => (true, 2),
     };
 
     // The number of fields that can be handled without an array.
@@ -226,7 +226,7 @@ fn show_fieldless_enum(
                     debug_assert!(fields.is_empty());
                     cx.pat_tuple_struct(span, variant_path, ThinVec::new())
                 }
-                ast::VariantData::Struct(fields, _) => {
+                ast::VariantData::Struct { fields, .. } => {
                     debug_assert!(fields.is_empty());
                     cx.pat_struct(span, variant_path, ThinVec::new())
                 }

compiler/rustc_builtin_macros/src/deriving/generic/mod.rs

@@ -1485,7 +1485,7 @@ impl<'a> TraitDef<'a> {
 
                 let struct_path = struct_path.clone();
                 match *struct_def {
-                    VariantData::Struct(..) => {
+                    VariantData::Struct { .. } => {
                         let field_pats = pieces_iter
                             .map(|(sp, ident, pat)| {
                                 if ident.is_none() {

compiler/rustc_expand/src/placeholders.rs

@@ -174,7 +174,7 @@ pub fn placeholder(
         }]),
         AstFragmentKind::Variants => AstFragment::Variants(smallvec![ast::Variant {
             attrs: Default::default(),
-            data: ast::VariantData::Struct(Default::default(), false),
+            data: ast::VariantData::Struct { fields: Default::default(), recovered: false },
             disr_expr: None,
             id,
             ident,

compiler/rustc_hir/src/def.rs

@@ -603,7 +603,7 @@ impl CtorKind {
         match *vdata {
             ast::VariantData::Tuple(_, node_id) => Some((CtorKind::Fn, node_id)),
             ast::VariantData::Unit(node_id) => Some((CtorKind::Const, node_id)),
-            ast::VariantData::Struct(..) => None,
+            ast::VariantData::Struct { .. } => None,
         }
     }
 }

compiler/rustc_hir/src/hir.rs

@@ -2848,7 +2848,11 @@ pub enum VariantData<'hir> {
     /// A struct variant.
     ///
     /// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
-    Struct(&'hir [FieldDef<'hir>], /* recovered */ bool),
+    Struct {
+        fields: &'hir [FieldDef<'hir>],
+        // FIXME: investigate making this a `Option<ErrorGuaranteed>`
+        recovered: bool,
+    },
     /// A tuple variant.
     ///
     /// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
@@ -2863,7 +2867,7 @@ impl<'hir> VariantData<'hir> {
     /// Return the fields of this variant.
     pub fn fields(&self) -> &'hir [FieldDef<'hir>] {
         match *self {
-            VariantData::Struct(ref fields, ..) | VariantData::Tuple(ref fields, ..) => fields,
+            VariantData::Struct { fields, .. } | VariantData::Tuple(fields, ..) => fields,
             _ => &[],
         }
     }
@@ -2872,7 +2876,7 @@ impl<'hir> VariantData<'hir> {
         match *self {
             VariantData::Tuple(_, hir_id, def_id) => Some((CtorKind::Fn, hir_id, def_id)),
             VariantData::Unit(hir_id, def_id) => Some((CtorKind::Const, hir_id, def_id)),
-            VariantData::Struct(..) => None,
+            VariantData::Struct { .. } => None,
         }
     }
 

compiler/rustc_hir_analysis/src/collect.rs

@@ -814,7 +814,7 @@ fn convert_variant(
         })
         .collect();
     let recovered = match def {
-        hir::VariantData::Struct(_, r) => *r,
+        hir::VariantData::Struct { recovered, .. } => *recovered,
         _ => false,
     };
     ty::VariantDef::new(

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -481,7 +481,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<Ty
         },
 
         Node::Ctor(def) | Node::Variant(Variant { data: def, .. }) => match def {
-            VariantData::Unit(..) | VariantData::Struct(..) => {
+            VariantData::Unit(..) | VariantData::Struct { .. } => {
                 tcx.type_of(tcx.hir().get_parent_item(hir_id)).instantiate_identity()
             }
             VariantData::Tuple(..) => {

compiler/rustc_hir_pretty/src/lib.rs

@@ -741,7 +741,7 @@ impl<'a> State<'a> {
                 self.end();
                 self.end() // close the outer-box
             }
-            hir::VariantData::Struct(..) => {
+            hir::VariantData::Struct { .. } => {
                 self.print_where_clause(generics);
                 self.nbsp();
                 self.bopen();

compiler/rustc_parse/src/parser/item.rs

@@ -1484,7 +1484,7 @@ impl<'a> Parser<'a> {
                                 (thin_vec![], true)
                             }
                         };
-                    VariantData::Struct(fields, recovered)
+                    VariantData::Struct { fields, recovered }
                 } else if this.check(&token::OpenDelim(Delimiter::Parenthesis)) {
                     let body = match this.parse_tuple_struct_body() {
                         Ok(body) => body,
@@ -1569,7 +1569,7 @@ impl<'a> Parser<'a> {
                     class_name.span,
                     generics.where_clause.has_where_token,
                 )?;
-                VariantData::Struct(fields, recovered)
+                VariantData::Struct { fields, recovered }
             }
         // No `where` so: `struct Foo<T>;`
         } else if self.eat(&token::Semi) {
@@ -1581,7 +1581,7 @@ impl<'a> Parser<'a> {
                 class_name.span,
                 generics.where_clause.has_where_token,
             )?;
-            VariantData::Struct(fields, recovered)
+            VariantData::Struct { fields, recovered }
         // Tuple-style struct definition with optional where-clause.
         } else if self.token == token::OpenDelim(Delimiter::Parenthesis) {
             let body = VariantData::Tuple(self.parse_tuple_struct_body()?, DUMMY_NODE_ID);
@@ -1610,14 +1610,14 @@ impl<'a> Parser<'a> {
                 class_name.span,
                 generics.where_clause.has_where_token,
             )?;
-            VariantData::Struct(fields, recovered)
+            VariantData::Struct { fields, recovered }
         } else if self.token == token::OpenDelim(Delimiter::Brace) {
             let (fields, recovered) = self.parse_record_struct_body(
                 "union",
                 class_name.span,
                 generics.where_clause.has_where_token,
             )?;
-            VariantData::Struct(fields, recovered)
+            VariantData::Struct { fields, recovered }
         } else {
             let token_str = super::token_descr(&self.token);
             let msg = format!("expected `where` or `{{` after union name, found {token_str}");

src/librustdoc/clean/mod.rs

@@ -2479,8 +2479,8 @@ fn clean_variant_data<'tcx>(
         .map(|disr| Discriminant { expr: Some(disr.body), value: disr.def_id.to_def_id() });
 
     let kind = match variant {
-        hir::VariantData::Struct(..) => VariantKind::Struct(VariantStruct {
+        hir::VariantData::Struct { fields, .. } => VariantKind::Struct(VariantStruct {
-            fields: variant.fields().iter().map(|x| clean_field(x, cx)).collect(),
+            fields: fields.iter().map(|x| clean_field(x, cx)).collect(),
         }),
         hir::VariantData::Tuple(..) => {
             VariantKind::Tuple(variant.fields().iter().map(|x| clean_field(x, cx)).collect())

src/tools/clippy/clippy_lints/src/item_name_repetitions.rs

@@ -436,7 +436,7 @@ impl LateLintPass<'_> for ItemNameRepetitions {
         {
             match item.kind {
                 ItemKind::Enum(def, _) => check_variant(cx, self.enum_threshold, &def, item_name, item.span),
-                ItemKind::Struct(VariantData::Struct(fields, _), _) => {
+                ItemKind::Struct(VariantData::Struct { fields, .. }, _) => {
                     check_fields(cx, self.struct_threshold, item, fields);
                 },
                 _ => (),

src/tools/clippy/clippy_lints/src/manual_non_exhaustive.rs

@@ -103,7 +103,7 @@ impl EarlyLintPass for ManualNonExhaustiveStruct {
 
         if let ast::ItemKind::Struct(variant_data, _) = &item.kind {
             let (fields, delimiter) = match variant_data {
-                ast::VariantData::Struct(fields, _) => (&**fields, '{'),
+                ast::VariantData::Struct { fields, .. } => (&**fields, '{'),
                 ast::VariantData::Tuple(fields, _) => (&**fields, '('),
                 ast::VariantData::Unit(_) => return,
             };

src/tools/clippy/clippy_utils/src/ast_utils.rs

@@ -546,7 +546,9 @@ pub fn eq_variant_data(l: &VariantData, r: &VariantData) -> bool {
     use VariantData::*;
     match (l, r) {
         (Unit(_), Unit(_)) => true,
-        (Struct(l, _), Struct(r, _)) | (Tuple(l, _), Tuple(r, _)) => over(l, r, eq_struct_field),
+        (Struct { fields: l, .. }, Struct { fields: r, .. }) | (Tuple(l, _), Tuple(r, _)) => {
+            over(l, r, eq_struct_field)
+        },
         _ => false,
     }
 }

src/tools/clippy/clippy_utils/src/check_proc_macro.rs

@@ -200,7 +200,7 @@ fn item_search_pat(item: &Item<'_>) -> (Pat, Pat) {
         ItemKind::ForeignMod { .. } => (Pat::Str("extern"), Pat::Str("}")),
         ItemKind::TyAlias(..) | ItemKind::OpaqueTy(_) => (Pat::Str("type"), Pat::Str(";")),
         ItemKind::Enum(..) => (Pat::Str("enum"), Pat::Str("}")),
-        ItemKind::Struct(VariantData::Struct(..), _) => (Pat::Str("struct"), Pat::Str("}")),
+        ItemKind::Struct(VariantData::Struct { .. }, _) => (Pat::Str("struct"), Pat::Str("}")),
         ItemKind::Struct(..) => (Pat::Str("struct"), Pat::Str(";")),
         ItemKind::Union(..) => (Pat::Str("union"), Pat::Str("}")),
         ItemKind::Trait(_, Unsafety::Unsafe, ..)
@@ -255,7 +255,7 @@ fn field_def_search_pat(def: &FieldDef<'_>) -> (Pat, Pat) {
 
 fn variant_search_pat(v: &Variant<'_>) -> (Pat, Pat) {
     match v.data {
-        VariantData::Struct(..) => (Pat::Sym(v.ident.name), Pat::Str("}")),
+        VariantData::Struct { .. } => (Pat::Sym(v.ident.name), Pat::Str("}")),
         VariantData::Tuple(..) => (Pat::Sym(v.ident.name), Pat::Str("")),
         VariantData::Unit(..) => (Pat::Sym(v.ident.name), Pat::Sym(v.ident.name)),
     }

src/tools/rustfmt/src/items.rs

@@ -666,7 +666,7 @@ impl<'a> FmtVisitor<'a> {
         let span = mk_sp(lo, field.span.lo());
 
         let variant_body = match field.data {
-            ast::VariantData::Tuple(..) | ast::VariantData::Struct(..) => format_struct(
+            ast::VariantData::Tuple(..) | ast::VariantData::Struct { .. } => format_struct(
                 &context,
                 &StructParts::from_variant(field, &context),
                 self.block_indent,
@@ -1092,7 +1092,7 @@ fn enum_variant_span(variant: &ast::Variant, context: &RewriteContext<'_>) -> Sp
     if let Some(ref anon_const) = variant.disr_expr {
         let span_before_consts = variant.span.until(anon_const.value.span);
         let hi = match &variant.data {
-            Struct(..) => context
+            Struct { .. } => context
                 .snippet_provider
                 .span_after_last(span_before_consts, "}"),
             Tuple(..) => context
@@ -1112,12 +1112,12 @@ fn format_struct(
     offset: Indent,
     one_line_width: Option<usize>,
 ) -> Option<String> {
-    match *struct_parts.def {
+    match struct_parts.def {
         ast::VariantData::Unit(..) => format_unit_struct(context, struct_parts, offset),
-        ast::VariantData::Tuple(ref fields, _) => {
+        ast::VariantData::Tuple(fields, _) => {
             format_tuple_struct(context, struct_parts, fields, offset)
         }
-        ast::VariantData::Struct(ref fields, _) => {
+        ast::VariantData::Struct { fields, .. } => {
             format_struct_struct(context, struct_parts, fields, offset, one_line_width)
         }
     }