Add constness field to hir::ItemKind::Impl

Author: ecstatic-morse

src/librustc_ast_lowering/item.rs

@@ -365,7 +365,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 unsafety,
                 polarity,
                 defaultness,
-                constness: _, // TODO
+                constness,
                 generics: ref ast_generics,
                 of_trait: ref trait_ref,
                 self_ty: ref ty,
@@ -422,6 +422,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     unsafety,
                     polarity,
                     defaultness: self.lower_defaultness(defaultness, true /* [1] */),
+                    constness,
                     generics,
                     of_trait: trait_ref,
                     self_ty: lowered_ty,

src/librustc_hir/hir.rs

@@ -2440,6 +2440,7 @@ pub enum ItemKind<'hir> {
         unsafety: Unsafety,
         polarity: ImplPolarity,
         defaultness: Defaultness,
+        constness: Constness,
         generics: Generics<'hir>,
 
         /// The trait being implemented, if any.

src/librustc_hir/intravisit.rs

@@ -570,6 +570,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
             unsafety: _,
             defaultness: _,
             polarity: _,
+            constness: _,
             ref generics,
             ref of_trait,
             ref self_ty,

src/librustc_hir/print.rs

@@ -631,6 +631,7 @@ impl<'a> State<'a> {
                 unsafety,
                 polarity,
                 defaultness,
+                constness,
                 ref generics,
                 ref of_trait,
                 ref self_ty,
@@ -647,6 +648,10 @@ impl<'a> State<'a> {
                     self.s.space();
                 }
 
+                if constness == ast::Constness::Const {
+                    self.word_nbsp("const");
+                }
+
                 if let hir::ImplPolarity::Negative = polarity {
                     self.s.word("!");
                 }

src/librustdoc/doctree.rs

@@ -203,6 +203,7 @@ pub struct Impl<'hir> {
     pub unsafety: hir::Unsafety,
     pub polarity: hir::ImplPolarity,
     pub defaultness: hir::Defaultness,
+    pub constness: ast::Constness,
     pub generics: &'hir hir::Generics<'hir>,
     pub trait_: &'hir Option<hir::TraitRef<'hir>>,
     pub for_: &'hir hir::Ty<'hir>,

src/librustdoc/visit_ast.rs

@@ -562,6 +562,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 unsafety,
                 polarity,
                 defaultness,
+                constness,
                 ref generics,
                 ref of_trait,
                 self_ty,
@@ -576,6 +577,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                         unsafety,
                         polarity,
                         defaultness,
+                        constness,
                         generics,
                         trait_: of_trait,
                         for_: self_ty,