do not access typeck_tables map directly

src/librustc_save_analysis/dump_visitor.rs

@@ -114,15 +114,11 @@ impl<'l, 'tcx: 'l, 'll, D: Dump + 'll> DumpVisitor<'l, 'tcx, 'll, D> {
         where F: FnOnce(&mut DumpVisitor<'l, 'tcx, 'll, D>)
     {
         let item_def_id = self.tcx.hir.local_def_id(item_id);
-        match self.tcx.maps.typeck_tables_of.borrow().get(&item_def_id) {
-            Some(tables) => {
-                let old_tables = self.save_ctxt.tables;
-                self.save_ctxt.tables = tables;
-                f(self);
-                self.save_ctxt.tables = old_tables;
-            }
-            None => f(self),
-        }
+        let tables = self.tcx.typeck_tables_of(item_def_id);
+        let old_tables = self.save_ctxt.tables;
+        self.save_ctxt.tables = tables;
+        f(self);
+        self.save_ctxt.tables = old_tables;
     }
 
     pub fn dump_crate_info(&mut self, name: &str, krate: &ast::Crate) {

src/librustc_typeck/check_unused.rs

@@ -66,14 +66,10 @@ pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
         let item_id = tcx.hir.body_owner(body_id);
         let item_def_id = tcx.hir.local_def_id(item_id);
 
-        // this will have been written by the main typeck pass
-        if let Some(tables) = tcx.maps.typeck_tables_of.borrow().get(&item_def_id) {
-            let imports = &tables.used_trait_imports;
-            debug!("GatherVisitor: item_def_id={:?} with imports {:#?}", item_def_id, imports);
-            used_trait_imports.extend(imports);
-        } else {
-            debug!("GatherVisitor: item_def_id={:?} with no imports", item_def_id);
-        }
+        let tables = tcx.typeck_tables_of(item_def_id);
+        let imports = &tables.used_trait_imports;
+        debug!("GatherVisitor: item_def_id={:?} with imports {:#?}", item_def_id, imports);
+        used_trait_imports.extend(imports);
     }
 
     let mut visitor = CheckVisitor { tcx, used_trait_imports };