[es6] More efficient way of marking AST call expressions in tail positions.

src/parsing/parser-base.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_PARSING_PARSER_BASE_H
 #define V8_PARSING_PARSER_BASE_H
 
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
 #include "src/hashmap.h"
@@ skipping 228 matching lines @@
 
     const List<DestructuringAssignment>& destructuring_assignments_to_rewrite()
         const {
       return destructuring_assignments_to_rewrite_;
     }
 
     void AddDestructuringAssignment(DestructuringAssignment pair) {
       destructuring_assignments_to_rewrite_.Add(pair);
     }
 
+    List<ExpressionT>& expressions_in_tail_position() {
+      return expressions_in_tail_position_;
+    }
+    void AddExpressionInTailPosition(ExpressionT expression) {
+      if (collect_expressions_in_tail_position_) {
+        expressions_in_tail_position_.Add(expression);
+      }
+    }
+
+    bool collect_expressions_in_tail_position() const {
+      return collect_expressions_in_tail_position_;
+    }
+    void set_collect_expressions_in_tail_position(bool collect) {
+      collect_expressions_in_tail_position_ = collect;
+    }
+
    private:
     // Used to assign an index to each literal that needs materialization in
     // the function.  Includes regexp literals, and boilerplate for object and
     // array literals.
     int next_materialized_literal_index_;
 
     // Properties count estimation.
     int expected_property_count_;
 
     // Location of most recent use of 'this' (invalid if none).
@@ skipping 10 matching lines @@
     // is used by yield expressions and return statements. It is not necessary
     // for generator functions to have this variable set.
     Variable* generator_object_variable_;
 
     FunctionState** function_state_stack_;
     FunctionState* outer_function_state_;
     Scope** scope_stack_;
     Scope* outer_scope_;
 
     List<DestructuringAssignment> destructuring_assignments_to_rewrite_;
+    List<ExpressionT> expressions_in_tail_position_;
+    bool collect_expressions_in_tail_position_;
 
     void RewriteDestructuringAssignments();
 
     typename Traits::Type::Factory* factory_;
 
     friend class ParserTraits;
     friend class Checkpoint;
   };
 
   // Annoyingly, arrow functions first parse as comma expressions, then when we
@@ skipping 637 matching lines @@
   bool allow_harmony_sloppy_let_;
   bool allow_harmony_default_parameters_;
   bool allow_harmony_destructuring_bind_;
   bool allow_harmony_destructuring_assignment_;
   bool allow_strong_mode_;
   bool allow_legacy_const_;
   bool allow_harmony_do_expressions_;
   bool allow_harmony_function_name_;
 };
 
-
 template <class Traits>
 ParserBase<Traits>::FunctionState::FunctionState(
     FunctionState** function_state_stack, Scope** scope_stack, Scope* scope,
     FunctionKind kind, typename Traits::Type::Factory* factory)
     : next_materialized_literal_index_(0),
       expected_property_count_(0),
       this_location_(Scanner::Location::invalid()),
       return_location_(Scanner::Location::invalid()),
       super_location_(Scanner::Location::invalid()),
       kind_(kind),
       generator_object_variable_(NULL),
       function_state_stack_(function_state_stack),
       outer_function_state_(*function_state_stack),
       scope_stack_(scope_stack),
       outer_scope_(*scope_stack),
+      collect_expressions_in_tail_position_(true),
       factory_(factory) {
   *scope_stack_ = scope;
   *function_state_stack = this;
 }
 
 
 template <class Traits>
 ParserBase<Traits>::FunctionState::~FunctionState() {
   *scope_stack_ = outer_scope_;
   *function_state_stack_ = outer_function_state_;
@@ skipping 2412 matching lines @@
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H