[parser] Refactor AstTraversalVisitor

src/parsing/parameter-initializer-rewriter.cc

Index: src/parsing/parameter-initializer-rewriter.cc
diff --git a/src/parsing/parameter-initializer-rewriter.cc b/src/parsing/parameter-initializer-rewriter.cc
index 4bb367d7d08ba91dae3ac67a42a4a3705455f179..dbf49157c0ec6d651e56da32da599800f7f82a31 100644
--- a/src/parsing/parameter-initializer-rewriter.cc
+++ b/src/parsing/parameter-initializer-rewriter.cc
@@ -8,9 +8,7 @@
 #include <utility>
 #include <vector>
 
-#include "src/ast/ast.h"
-#include "src/ast/ast-expression-visitor.h"
-#include "src/ast/scopes.h"
+#include "src/ast/ast-traversal-visitor.h"
 
 namespace v8 {
 namespace internal {
@@ -18,28 +16,29 @@ namespace internal {
 namespace {
 
 
-class Rewriter final : public AstExpressionVisitor {
+class Rewriter final : public AstTraversalVisitor<Rewriter> {
  public:
   Rewriter(uintptr_t stack_limit, Expression* initializer, Scope* old_scope,
            Scope* new_scope)
-      : AstExpressionVisitor(stack_limit, initializer),
+      : AstTraversalVisitor(stack_limit, initializer),
         old_scope_(old_scope),
         new_scope_(new_scope),
         old_scope_closure_(old_scope->ClosureScope()),
         new_scope_closure_(new_scope->ClosureScope()) {}
   ~Rewriter();
 
- private:
-  void VisitExpression(Expression* expr) override {}
+ protected:

[adamk, 2016/07/21 18:11:57]

"protected" + "final" doesn't make sense to me. Presumably these methods could
stay private; if you want to mark them in some way, a comment seems better than
this use of "protected"

[nickie, 2016/07/22 08:40:18]

You're right.  I'm making them private again.  These are the only ones that the
friend class needs to be able to call and I'm adding a comment explaining that.

+  friend class AstTraversalVisitor<Rewriter>;
 
-  void VisitFunctionLiteral(FunctionLiteral* expr) override;
-  void VisitClassLiteral(ClassLiteral* expr) override;
-  void VisitVariableProxy(VariableProxy* expr) override;
+  void VisitFunctionLiteral(FunctionLiteral* expr);
+  void VisitClassLiteral(ClassLiteral* expr);
+  void VisitVariableProxy(VariableProxy* expr);
 
-  void VisitBlock(Block* stmt) override;
-  void VisitTryCatchStatement(TryCatchStatement* stmt) override;
-  void VisitWithStatement(WithStatement* stmt) override;
+  void VisitBlock(Block* stmt);
+  void VisitTryCatchStatement(TryCatchStatement* stmt);
+  void VisitWithStatement(WithStatement* stmt);
 
+ private:
   Scope* old_scope_;
   Scope* new_scope_;
   Scope* old_scope_closure_;