Rework the `IdVisitor` so that it only visits item contents (and doesn't

visit nested items). This is what all clients wanted anyhow.

src/librustc/lint/context.rs

@@ -555,7 +555,6 @@ fn visit_ids<F>(&mut self, f: F)
     {
         let mut v = ast_util::IdVisitor {
             operation: self,
-            pass_through_items: false,
             visited_outermost: false,
         };
         f(&mut v);
@@ -583,11 +582,7 @@ fn new(tcx: &'a ty::ctxt<'tcx>,
     fn visit_ids<F>(&mut self, f: F)
         where F: FnOnce(&mut util::IdVisitor<LateContext>)
     {
-        let mut v = util::IdVisitor {
-            operation: self,
-            pass_through_items: false,
-            visited_outermost: false,
-        };
+        let mut v = util::IdVisitor::new(self);
         f(&mut v);
     }
 }

src/librustc/metadata/inline.rs

@@ -48,11 +48,7 @@ pub fn visit<'ast,V>(&'ast self, visitor: &mut V)
     }
 
     pub fn visit_ids<O: IdVisitingOperation>(&self, operation: &mut O) {
-        let mut id_visitor = IdVisitor {
-            operation: operation,
-            pass_through_items: true,
-            visited_outermost: false,
-        };
+        let mut id_visitor = IdVisitor::new(operation);
         self.visit(&mut id_visitor);
     }
 

src/librustc/middle/check_match.rs

@@ -485,11 +485,7 @@ fn record_renamings(const_expr: &hir::Expr,
                 renaming_map: renaming_map,
             };
 
-            let mut id_visitor = front_util::IdVisitor {
-                operation: &mut renaming_recorder,
-                pass_through_items: true,
-                visited_outermost: false,
-            };
+            let mut id_visitor = front_util::IdVisitor::new(&mut renaming_recorder);
 
             id_visitor.visit_expr(const_expr);
         }

src/libsyntax/ast_util.rs

@@ -289,7 +289,6 @@ pub trait IdVisitingOperation {
 
 pub struct IdVisitor<'a, O:'a> {
     pub operation: &'a mut O,
-    pub pass_through_items: bool,
     pub visited_outermost: bool,
 }
 
@@ -319,12 +318,10 @@ fn visit_foreign_item(&mut self, foreign_item: &ForeignItem) {
     }
 
     fn visit_item(&mut self, item: &Item) {
-        if !self.pass_through_items {
-            if self.visited_outermost {
-                return
-            } else {
-                self.visited_outermost = true
-            }
+        if self.visited_outermost {
+            return
+        } else {
+            self.visited_outermost = true
         }
 
         self.operation.visit_id(item.id);
@@ -390,12 +387,10 @@ fn visit_fn(&mut self,
                 block: &'v Block,
                 span: Span,
                 node_id: NodeId) {
-        if !self.pass_through_items {
-            match function_kind {
-                FnKind::Method(..) if self.visited_outermost => return,
-                FnKind::Method(..) => self.visited_outermost = true,
-                _ => {}
-            }
+        match function_kind {
+            FnKind::Method(..) if self.visited_outermost => return,
+            FnKind::Method(..) => self.visited_outermost = true,
+            _ => {}
         }
 
         self.operation.visit_id(node_id);
@@ -420,10 +415,8 @@ fn visit_fn(&mut self,
                        block,
                        span);
 
-        if !self.pass_through_items {
-            if let FnKind::Method(..) = function_kind {
-                self.visited_outermost = false;
-            }
+        if let FnKind::Method(..) = function_kind {
+            self.visited_outermost = false;
         }
     }
 
@@ -497,7 +490,6 @@ pub fn compute_id_range_for_fn_body(fk: FnKind,
     let mut visitor = IdRangeComputingVisitor::new();
     let mut id_visitor = IdVisitor {
         operation: &mut visitor,
-        pass_through_items: false,
         visited_outermost: false,
     };
     id_visitor.visit_fn(fk, decl, body, sp, id);