Unify walk_path

Author: maxcabrajac

compiler/rustc_ast/src/visitors.rs

@@ -354,6 +354,7 @@ macro_rules! make_ast_visitor {
                 walk_use_tree(self, use_tree, id)
             }
 
+            /// Id should be visited by the caller
             fn visit_path(&mut self, path: ref_t!(Path), _id: NodeId) -> result!() {
                 walk_path(self, path)
             }
@@ -381,6 +382,18 @@ macro_rules! make_ast_visitor {
             }
         }
 
+        macro_rules! visit_lazy_tts {
+            ($vis: expr, $tokens: expr) => {
+                if_mut_expr!(
+                    visit_lazy_tts($vis, $tokens)
+                ,
+                    // assign to _ to prevent unused_variable warnings
+                    { let _ = (&$vis, &$tokens); }
+                );
+            }
+        }
+
+
         // FIXME: should only exist while Visitor::visit_ident
         // doesn't receives a reference
         macro_rules! visit_ident {
@@ -419,7 +432,12 @@ macro_rules! make_ast_visitor {
                         try_v!($visitor.$visit(elem));
                     }
                 )
-            }
+            };
+            ($visitor: expr, $visit: ident, $list: expr) => {
+                for elem in $list {
+                    try_v!($visitor.$visit(elem));
+                }
+            };
         }
 
         // TODO: temporary name
@@ -829,8 +847,7 @@ macro_rules! make_ast_visitor {
                     try_v!(vis.visit_block(els));
                 }
             }
-            // TODO: Weird
-            if_mut_expr!(visit_lazy_tts(vis, tokens), { let _ = tokens; });
+            visit_lazy_tts!(vis, tokens);
             visit_o!(colon_sp, |sp| try_v!(visit_span!(vis, sp)));
             try_v!(visit_span!(vis, span));
             return_result!(V)
@@ -861,6 +878,17 @@ macro_rules! make_ast_visitor {
             return_result!(V)
         }
 
+        pub fn walk_path<$($lt,)? V: $trait$(<$lt>)?>(
+            vis: &mut V,
+            path: ref_t!(Path)
+        ) -> result!(V) {
+            let Path { span, segments, tokens } = path;
+            visit_list!(vis, visit_path_segment, segments);
+            visit_lazy_tts!(vis, tokens);
+            try_v!(visit_span!(vis, span));
+            return_result!(V)
+        }
+
         make_walk_flat_map!{Arm, walk_flat_map_arm, visit_arm}
         make_walk_flat_map!{Attribute, walk_flat_map_attribute, visit_attribute}
         make_walk_flat_map!{ExprField, walk_flat_map_expr_field, visit_expr_field}
@@ -1175,12 +1203,6 @@ pub mod visit {
         V::Result::output()
     }
 
-    pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) -> V::Result {
-        let Path { span: _, segments, tokens: _ } = path;
-        walk_list!(visitor, visit_path_segment, segments);
-        V::Result::output()
-    }
-
     pub fn walk_generic_arg<'a, V>(visitor: &mut V, generic_arg: &'a GenericArg) -> V::Result
     where
         V: Visitor<'a>,
@@ -1932,14 +1954,6 @@ pub mod mut_visit {
         items.flat_map_in_place(|item| vis.flat_map_foreign_item(item));
     }
 
-    fn walk_path<T: MutVisitor>(vis: &mut T, Path { segments, span, tokens }: &mut Path) {
-        for segment in segments {
-            vis.visit_path_segment(segment);
-        }
-        visit_lazy_tts(vis, tokens);
-        vis.visit_span(span);
-    }
-
     fn walk_generic_arg<T: MutVisitor>(vis: &mut T, arg: &mut GenericArg) {
         match arg {
             GenericArg::Lifetime(lt) => vis.visit_lifetime(lt),