For-of calls [Symbol.iterator]() on RHS to get iterator

src/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_AST_H_
 #define V8_AST_H_
 
 #include "src/v8.h"
 
 #include "src/assembler.h"
@@ skipping 938 matching lines @@
 };
 
 
 class ForOfStatement V8_FINAL : public ForEachStatement {
  public:
   DECLARE_NODE_TYPE(ForOfStatement)
 
   void Initialize(Expression* each,
                   Expression* subject,
                   Statement* body,
+                  Expression* assign_iterable,
                   Expression* assign_iterator,
                   Expression* next_result,
                   Expression* result_done,
                   Expression* assign_each) {
     ForEachStatement::Initialize(each, subject, body);
+    assign_iterable_ = assign_iterable;
     assign_iterator_ = assign_iterator;
     next_result_ = next_result;
     result_done_ = result_done;
     assign_each_ = assign_each;
   }
 
   Expression* iterable() const {
     return subject();
   }
 
-  // var iterator = iterable;
+  // var iterable = subject;
+  Expression* assign_iterable() const {
+    return assign_iterable_;
+  }
+
+  // var iterator = iterable[Symbol.iterator]();
   Expression* assign_iterator() const {
     return assign_iterator_;
   }
 
   // var result = iterator.next();
   Expression* next_result() const {
     return next_result_;
   }
 
   // result.done
@@ skipping 14 matching lines @@
  protected:
   ForOfStatement(Zone* zone, ZoneStringList* labels, int pos)
       : ForEachStatement(zone, labels, pos),
         assign_iterator_(NULL),
         next_result_(NULL),
         result_done_(NULL),
         assign_each_(NULL),
         back_edge_id_(GetNextId(zone)) {
   }
 
+  Expression* assign_iterable_;
   Expression* assign_iterator_;
   Expression* next_result_;
   Expression* result_done_;
   Expression* assign_each_;
   const BailoutId back_edge_id_;
 };
 
 
 class ExpressionStatement V8_FINAL : public Statement {
  public:
@@ skipping 2319 matching lines @@
 
  private:
   Zone* zone_;
   Visitor visitor_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_