Pull some tuple variant fields out into their own struct

compiler/rustc_ast/src/ast.rs

@@ -2890,6 +2890,20 @@ pub struct Fn {
     pub body: Option<P<Block>>,
 }
 
+#[derive(Clone, Encodable, Decodable, Debug)]
+pub struct StaticItem {
+    pub ty: P<Ty>,
+    pub mutability: Mutability,
+    pub expr: Option<P<Expr>>,
+}
+
+#[derive(Clone, Encodable, Decodable, Debug)]
+pub struct ConstItem {
+    pub defaultness: Defaultness,
+    pub ty: P<Ty>,
+    pub expr: Option<P<Expr>>,
+}
+
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub enum ItemKind {
     /// An `extern crate` item, with the optional *original* crate name if the crate was renamed.
@@ -2903,11 +2917,11 @@ pub enum ItemKind {
     /// A static item (`static`).
     ///
     /// E.g., `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`.
-    Static(P<Ty>, Mutability, Option<P<Expr>>),
+    Static(Box<StaticItem>),
     /// A constant item (`const`).
     ///
     /// E.g., `const FOO: i32 = 42;`.
-    Const(Defaultness, P<Ty>, Option<P<Expr>>),
+    Const(Box<ConstItem>),
     /// A function declaration (`fn`).
     ///
     /// E.g., `fn foo(bar: usize) -> usize { .. }`.
@@ -3023,7 +3037,7 @@ pub type AssocItem = Item<AssocItemKind>;
 pub enum AssocItemKind {
     /// An associated constant, `const $ident: $ty $def?;` where `def ::= "=" $expr? ;`.
     /// If `def` is parsed, then the constant is provided, and otherwise required.
-    Const(Defaultness, P<Ty>, Option<P<Expr>>),
+    Const(Box<ConstItem>),
     /// An associated function.
     Fn(Box<Fn>),
     /// An associated type.
@@ -3035,7 +3049,7 @@ pub enum AssocItemKind {
 impl AssocItemKind {
     pub fn defaultness(&self) -> Defaultness {
         match *self {
-            Self::Const(defaultness, ..)
+            Self::Const(box ConstItem { defaultness, .. })
             | Self::Fn(box Fn { defaultness, .. })
             | Self::Type(box TyAlias { defaultness, .. }) => defaultness,
             Self::MacCall(..) => Defaultness::Final,
@@ -3046,7 +3060,7 @@ impl AssocItemKind {
 impl From<AssocItemKind> for ItemKind {
     fn from(assoc_item_kind: AssocItemKind) -> ItemKind {
         match assoc_item_kind {
-            AssocItemKind::Const(a, b, c) => ItemKind::Const(a, b, c),
+            AssocItemKind::Const(item) => ItemKind::Const(item),
             AssocItemKind::Fn(fn_kind) => ItemKind::Fn(fn_kind),
             AssocItemKind::Type(ty_alias_kind) => ItemKind::TyAlias(ty_alias_kind),
             AssocItemKind::MacCall(a) => ItemKind::MacCall(a),
@@ -3059,7 +3073,7 @@ impl TryFrom<ItemKind> for AssocItemKind {
 
     fn try_from(item_kind: ItemKind) -> Result<AssocItemKind, ItemKind> {
         Ok(match item_kind {
-            ItemKind::Const(a, b, c) => AssocItemKind::Const(a, b, c),
+            ItemKind::Const(item) => AssocItemKind::Const(item),
             ItemKind::Fn(fn_kind) => AssocItemKind::Fn(fn_kind),
             ItemKind::TyAlias(ty_kind) => AssocItemKind::Type(ty_kind),
             ItemKind::MacCall(a) => AssocItemKind::MacCall(a),
@@ -3084,7 +3098,9 @@ pub enum ForeignItemKind {
 impl From<ForeignItemKind> for ItemKind {
     fn from(foreign_item_kind: ForeignItemKind) -> ItemKind {
         match foreign_item_kind {
-            ForeignItemKind::Static(a, b, c) => ItemKind::Static(a, b, c),
+            ForeignItemKind::Static(a, b, c) => {
+                ItemKind::Static(StaticItem { ty: a, mutability: b, expr: c }.into())
+            }
             ForeignItemKind::Fn(fn_kind) => ItemKind::Fn(fn_kind),
             ForeignItemKind::TyAlias(ty_alias_kind) => ItemKind::TyAlias(ty_alias_kind),
             ForeignItemKind::MacCall(a) => ItemKind::MacCall(a),
@@ -3097,7 +3113,9 @@ impl TryFrom<ItemKind> for ForeignItemKind {
 
     fn try_from(item_kind: ItemKind) -> Result<ForeignItemKind, ItemKind> {
         Ok(match item_kind {
-            ItemKind::Static(a, b, c) => ForeignItemKind::Static(a, b, c),
+            ItemKind::Static(box StaticItem { ty: a, mutability: b, expr: c }) => {
+                ForeignItemKind::Static(a, b, c)
+            }
             ItemKind::Fn(fn_kind) => ForeignItemKind::Fn(fn_kind),
             ItemKind::TyAlias(ty_alias_kind) => ForeignItemKind::TyAlias(ty_alias_kind),
             ItemKind::MacCall(a) => ForeignItemKind::MacCall(a),
@@ -3114,8 +3132,8 @@ mod size_asserts {
     use super::*;
     use rustc_data_structures::static_assert_size;
     // tidy-alphabetical-start
-    static_assert_size!(AssocItem, 104);
-    static_assert_size!(AssocItemKind, 32);
+    static_assert_size!(AssocItem, 88);
+    static_assert_size!(AssocItemKind, 16);
     static_assert_size!(Attribute, 32);
     static_assert_size!(Block, 32);
     static_assert_size!(Expr, 72);

compiler/rustc_ast/src/mut_visit.rs

@@ -7,10 +7,10 @@
 //! a `MutVisitor` renaming item names in a module will miss all of those
 //! that are created by the expansion of a macro.
 
-use crate::ast::*;
 use crate::ptr::P;
 use crate::token::{self, Token};
 use crate::tokenstream::*;
+use crate::{ast::*, StaticItem};
 
 use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
 use rustc_data_structures::sync::Lrc;
@@ -1030,14 +1030,12 @@ pub fn noop_visit_item_kind<T: MutVisitor>(kind: &mut ItemKind, vis: &mut T) {
     match kind {
         ItemKind::ExternCrate(_orig_name) => {}
         ItemKind::Use(use_tree) => vis.visit_use_tree(use_tree),
-        ItemKind::Static(ty, _, expr) => {
+        ItemKind::Static(box StaticItem { ty, mutability: _, expr }) => {
             vis.visit_ty(ty);
             visit_opt(expr, |expr| vis.visit_expr(expr));
         }
-        ItemKind::Const(defaultness, ty, expr) => {
-            visit_defaultness(defaultness, vis);
-            vis.visit_ty(ty);
-            visit_opt(expr, |expr| vis.visit_expr(expr));
+        ItemKind::Const(item) => {
+            visit_const_item(item, vis);
         }
         ItemKind::Fn(box Fn { defaultness, generics, sig, body }) => {
             visit_defaultness(defaultness, vis);
@@ -1120,10 +1118,8 @@ pub fn noop_flat_map_assoc_item<T: MutVisitor>(
     visitor.visit_vis(vis);
     visit_attrs(attrs, visitor);
     match kind {
-        AssocItemKind::Const(defaultness, ty, expr) => {
-            visit_defaultness(defaultness, visitor);
-            visitor.visit_ty(ty);
-            visit_opt(expr, |expr| visitor.visit_expr(expr));
+        AssocItemKind::Const(item) => {
+            visit_const_item(item, visitor);
         }
         AssocItemKind::Fn(box Fn { defaultness, generics, sig, body }) => {
             visit_defaultness(defaultness, visitor);
@@ -1153,6 +1149,15 @@ pub fn noop_flat_map_assoc_item<T: MutVisitor>(
     smallvec![item]
 }
 
+fn visit_const_item<T: MutVisitor>(
+    ConstItem { defaultness, ty, expr }: &mut ConstItem,
+    visitor: &mut T,
+) {
+    visit_defaultness(defaultness, visitor);
+    visitor.visit_ty(ty);
+    visit_opt(expr, |expr| visitor.visit_expr(expr));
+}
+
 pub fn noop_visit_fn_header<T: MutVisitor>(header: &mut FnHeader, vis: &mut T) {
     let FnHeader { unsafety, asyncness, constness, ext: _ } = header;
     visit_constness(constness, vis);

compiler/rustc_ast/src/visit.rs

@@ -13,7 +13,7 @@
 //! instance, a walker looking for item names in a module will miss all of
 //! those that are created by the expansion of a macro.
 
-use crate::ast::*;
+use crate::{ast::*, StaticItem};
 
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
@@ -305,8 +305,9 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
     match &item.kind {
         ItemKind::ExternCrate(_) => {}
         ItemKind::Use(use_tree) => visitor.visit_use_tree(use_tree, item.id, false),
-        ItemKind::Static(typ, _, expr) | ItemKind::Const(_, typ, expr) => {
-            visitor.visit_ty(typ);
+        ItemKind::Static(box StaticItem { ty, mutability: _, expr })
+        | ItemKind::Const(box ConstItem { ty, expr, .. }) => {
+            visitor.visit_ty(ty);
             walk_list!(visitor, visit_expr, expr);
         }
         ItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => {
@@ -674,7 +675,7 @@ pub fn walk_assoc_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a AssocItem,
     visitor.visit_ident(ident);
     walk_list!(visitor, visit_attribute, attrs);
     match kind {
-        AssocItemKind::Const(_, ty, expr) => {
+        AssocItemKind::Const(box ConstItem { ty, expr, .. }) => {
             visitor.visit_ty(ty);
             walk_list!(visitor, visit_expr, expr);
         }

compiler/rustc_ast_lowering/src/item.rs

@@ -229,12 +229,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
                 self.lower_use_tree(use_tree, &prefix, id, vis_span, ident, attrs)
             }
-            ItemKind::Static(t, m, e) => {
+            ItemKind::Static(box ast::StaticItem { ty: t, mutability: m, expr: e }) => {
                 let (ty, body_id) = self.lower_const_item(t, span, e.as_deref());
                 hir::ItemKind::Static(ty, *m, body_id)
             }
-            ItemKind::Const(_, t, e) => {
-                let (ty, body_id) = self.lower_const_item(t, span, e.as_deref());
+            ItemKind::Const(box ast::ConstItem { ty, expr, .. }) => {
+                let (ty, body_id) = self.lower_const_item(ty, span, expr.as_deref());
                 hir::ItemKind::Const(ty, body_id)
             }
             ItemKind::Fn(box Fn {
@@ -708,10 +708,10 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let trait_item_def_id = hir_id.expect_owner();
 
         let (generics, kind, has_default) = match &i.kind {
-            AssocItemKind::Const(_, ty, default) => {
+            AssocItemKind::Const(box ConstItem { ty, expr, .. }) => {
                 let ty =
                     self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::ConstTy));
-                let body = default.as_ref().map(|x| self.lower_const_body(i.span, Some(x)));
+                let body = expr.as_ref().map(|x| self.lower_const_body(i.span, Some(x)));
                 (hir::Generics::empty(), hir::TraitItemKind::Const(ty, body), body.is_some())
             }
             AssocItemKind::Fn(box Fn { sig, generics, body: None, .. }) => {
@@ -809,7 +809,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.lower_attrs(hir_id, &i.attrs);
 
         let (generics, kind) = match &i.kind {
-            AssocItemKind::Const(_, ty, expr) => {
+            AssocItemKind::Const(box ConstItem { ty, expr, .. }) => {
                 let ty =
                     self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::ConstTy));
                 (

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -9,8 +9,8 @@
 use itertools::{Either, Itertools};
 use rustc_ast::ptr::P;
 use rustc_ast::visit::{self, AssocCtxt, BoundKind, FnCtxt, FnKind, Visitor};
-use rustc_ast::walk_list;
 use rustc_ast::*;
+use rustc_ast::{walk_list, StaticItem};
 use rustc_ast_pretty::pprust::{self, State};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_macros::Subdiagnostic;
@@ -983,14 +983,14 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                     self.err_handler().emit_err(errors::FieldlessUnion { span: item.span });
                 }
             }
-            ItemKind::Const(def, .., None) => {
-                self.check_defaultness(item.span, *def);
+            ItemKind::Const(box ConstItem { defaultness, expr: None, .. }) => {
+                self.check_defaultness(item.span, *defaultness);
                 self.session.emit_err(errors::ConstWithoutBody {
                     span: item.span,
                     replace_span: self.ending_semi_or_hi(item.span),
                 });
             }
-            ItemKind::Static(.., None) => {
+            ItemKind::Static(box StaticItem { expr: None, .. }) => {
                 self.session.emit_err(errors::StaticWithoutBody {
                     span: item.span,
                     replace_span: self.ending_semi_or_hi(item.span),
@@ -1259,13 +1259,11 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
 
         if ctxt == AssocCtxt::Impl {
             match &item.kind {
-                AssocItemKind::Const(_, _, body) => {
-                    if body.is_none() {
-                        self.session.emit_err(errors::AssocConstWithoutBody {
-                            span: item.span,
-                            replace_span: self.ending_semi_or_hi(item.span),
-                        });
-                    }
+                AssocItemKind::Const(box ConstItem { expr: None, .. }) => {
+                    self.session.emit_err(errors::AssocConstWithoutBody {
+                        span: item.span,
+                        replace_span: self.ending_semi_or_hi(item.span),
+                    });
                 }
                 AssocItemKind::Fn(box Fn { body, .. }) => {
                     if body.is_none() {

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

@@ -2,6 +2,7 @@ use crate::pp::Breaks::Inconsistent;
 use crate::pprust::state::delimited::IterDelimited;
 use crate::pprust::state::{AnnNode, PrintState, State, INDENT_UNIT};
 
+use ast::StaticItem;
 use rustc_ast as ast;
 use rustc_ast::GenericBound;
 use rustc_ast::ModKind;
@@ -156,7 +157,7 @@ impl<'a> State<'a> {
                 self.print_use_tree(tree);
                 self.word(";");
             }
-            ast::ItemKind::Static(ty, mutbl, body) => {
+            ast::ItemKind::Static(box StaticItem { ty, mutability: mutbl, expr: body }) => {
                 let def = ast::Defaultness::Final;
                 self.print_item_const(
                     item.ident,
@@ -167,8 +168,15 @@ impl<'a> State<'a> {
                     def,
                 );
             }
-            ast::ItemKind::Const(def, ty, body) => {
-                self.print_item_const(item.ident, None, ty, body.as_deref(), &item.vis, *def);
+            ast::ItemKind::Const(box ast::ConstItem { defaultness, ty, expr }) => {
+                self.print_item_const(
+                    item.ident,
+                    None,
+                    ty,
+                    expr.as_deref(),
+                    &item.vis,
+                    *defaultness,
+                );
             }
             ast::ItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
                 self.print_fn_full(
@@ -507,8 +515,8 @@ impl<'a> State<'a> {
             ast::AssocItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
                 self.print_fn_full(sig, ident, generics, vis, *defaultness, body.as_deref(), attrs);
             }
-            ast::AssocItemKind::Const(def, ty, body) => {
-                self.print_item_const(ident, None, ty, body.as_deref(), vis, *def);
+            ast::AssocItemKind::Const(box ast::ConstItem { defaultness, ty, expr }) => {
+                self.print_item_const(ident, None, ty, expr.as_deref(), vis, *defaultness);
             }
             ast::AssocItemKind::Type(box ast::TyAlias {
                 defaultness,

compiler/rustc_builtin_macros/src/global_allocator.rs

@@ -25,12 +25,12 @@ pub fn expand(
     // FIXME - if we get deref patterns, use them to reduce duplication here
     let (item, is_stmt, ty_span) =
         if let Annotatable::Item(item) = &item
-            && let ItemKind::Static(ty, ..) = &item.kind
+            && let ItemKind::Static(box ast::StaticItem { ty, ..}) = &item.kind
         {
             (item, false, ecx.with_def_site_ctxt(ty.span))
         } else if let Annotatable::Stmt(stmt) = &item
             && let StmtKind::Item(item) = &stmt.kind
-            && let ItemKind::Static(ty, ..) = &item.kind
+            && let ItemKind::Static(box ast::StaticItem { ty, ..}) = &item.kind
         {
             (item, true, ecx.with_def_site_ctxt(ty.span))
         } else {