From 2ec5eab368b3320950007b07b00600b9a981827a Mon Sep 17 00:00:00 2001
From: Oliver Schneider <github35764891676564198441@oli-obk.de>
Date: Fri, 22 Jun 2018 12:03:44 +0200
Subject: [PATCH] Also place method impl trait into the surrounding module

---
 src/librustc/hir/lowering.rs | 62 ++++++++++++++++++++++++++++--------
 1 file changed, 49 insertions(+), 13 deletions(-)

diff --git a/src/librustc/hir/lowering.rs b/src/librustc/hir/lowering.rs
index a21d2b691351..b7260dded920 100644
--- a/src/librustc/hir/lowering.rs
+++ b/src/librustc/hir/lowering.rs
@@ -3076,6 +3076,45 @@ impl<'a> LoweringContext<'a> {
         }
     }
 
+    /// Lowers `impl Trait` items and appends them to the list
+    fn lower_impl_trait_ids(
+        &mut self,
+        decl: &FnDecl,
+        ids: &mut SmallVector<hir::ItemId>,
+    ) {
+        struct IdVisitor<'a> { ids: &'a mut SmallVector<hir::ItemId> }
+        impl<'a, 'b> Visitor<'a> for IdVisitor<'b> {
+            fn visit_ty(&mut self, ty: &'a Ty) {
+                match ty.node {
+                    | TyKind::Typeof(_)
+                    | TyKind::BareFn(_)
+                    => return,
+
+                    TyKind::ImplTrait(id, _) => self.ids.push(hir::ItemId { id }),
+                    _ => {},
+                }
+                visit::walk_ty(self, ty);
+            }
+            fn visit_path_segment(
+                &mut self,
+                path_span: Span,
+                path_segment: &'v PathSegment,
+            ) {
+                if let Some(ref p) = path_segment.parameters {
+                    if let PathParameters::Parenthesized(..) = **p {
+                        return;
+                    }
+                }
+                visit::walk_path_segment(self, path_span, path_segment)
+            }
+        }
+        let mut visitor = IdVisitor { ids };
+        match decl.output {
+            FunctionRetTy::Default(_) => {},
+            FunctionRetTy::Ty(ref ty) => visitor.visit_ty(ty),
+        }
+    }
+
     fn lower_item_id(&mut self, i: &Item) -> SmallVector<hir::ItemId> {
         match i.node {
             ItemKind::Use(ref use_tree) => {
@@ -3085,21 +3124,18 @@ impl<'a> LoweringContext<'a> {
             }
             ItemKind::MacroDef(..) => SmallVector::new(),
             ItemKind::Fn(ref decl, ..) => {
-                struct IdVisitor { ids: SmallVector<hir::ItemId> }
-                impl<'a> Visitor<'a> for IdVisitor {
-                    fn visit_ty(&mut self, ty: &'a Ty) {
-                        if let TyKind::ImplTrait(id, _) = ty.node {
-                            self.ids.push(hir::ItemId { id });
-                        }
-                        visit::walk_ty(self, ty);
+                let mut ids = SmallVector::one(hir::ItemId { id: i.id });
+                self.lower_impl_trait_ids(decl, &mut ids);
+                ids
+            },
+            ItemKind::Impl(.., ref items) => {
+                let mut ids = SmallVector::one(hir::ItemId { id: i.id });
+                for item in items {
+                    if let ImplItemKind::Method(ref sig, _) = item.node {
+                        self.lower_impl_trait_ids(&sig.decl, &mut ids);
                     }
                 }
-                let mut visitor = IdVisitor { ids: SmallVector::one(hir::ItemId { id: i.id }) };
-                match decl.output {
-                    FunctionRetTy::Default(_) => {},
-                    FunctionRetTy::Ty(ref ty) => visitor.visit_ty(ty),
-                }
-                visitor.ids
+                ids
             },
             _ => SmallVector::one(hir::ItemId { id: i.id }),
         }