[Interpreter] Avoid dereferencing handles on BytecodeGenerator for AST operations.

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index ad02c960f840d66ff44ecaa1d5d89fdb40bdc284..ed345cacec2754e434f178970b41f5645e5f5539 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -318,7 +318,9 @@ class Expression : public AstNode {
   // Symbols that cannot be parsed as array indices are considered property
   // names.  We do not treat symbols that can be array indexes as property
   // names because [] for string objects is handled only by keyed ICs.
-  bool IsPropertyName() const;
+  bool IsPropertyName(

[marja, 2016/08/08 08:20:13]

For all calls, the guarantee you want to give is that the call w/ kAllowed
yields the same result as the call w/ kDisallowed + CanonicalHandleScope, right?
Can this be documented somewhere?

[rmcilroy, 2016/08/08 13:05:56]

For GetCallType yes this is the case. For IsPropertyName both should actually
give the same result (even without CanonicalHandleScope), it's just that
kDisallowed might be slower since it uses StringToArrayIndex() instead of
String::ToArrayIndex().

Added comments as such.

+      HandleDereferenceMode deref_mode =
+          HandleDereferenceMode::kHandleDereferenceAllowed) const;
 
   // True iff the expression is a class or function expression without
   // a syntactic name.
@@ -1241,10 +1243,14 @@ class Literal final : public Expression {
  public:
   DECLARE_NODE_TYPE(Literal)
 
-  bool IsPropertyName() const { return value_->IsPropertyName(); }
+  bool IsPropertyName(
+      HandleDereferenceMode deref_mode =
+          HandleDereferenceMode::kHandleDereferenceAllowed) const {
+    return value_->IsPropertyName(deref_mode);
+  }
 
   Handle<String> AsPropertyName() {
-    DCHECK(IsPropertyName());
+    DCHECK(IsPropertyName(HandleDereferenceMode::kHandleDereferenceDisallowed));
     return Handle<String>::cast(value());
   }
 
@@ -1253,8 +1259,8 @@ class Literal final : public Expression {
     return value_->AsString();
   }
 
-  bool ToBooleanIsTrue() const { return value()->BooleanValue(); }
-  bool ToBooleanIsFalse() const { return !value()->BooleanValue(); }
+  bool ToBooleanIsTrue() const { return raw_value()->BooleanValue(); }
+  bool ToBooleanIsFalse() const { return !raw_value()->BooleanValue(); }
 
   Handle<Object> value() const { return value_->value(); }
   const AstValue* raw_value() const { return value_; }
@@ -1411,7 +1417,7 @@ class ObjectLiteral final : public MaterializedLiteral {
   Handle<FixedArray> constant_properties() const {
     return constant_properties_;
   }
-  int properties_count() const { return constant_properties_->length() / 2; }
+  int properties_count() const { return boilerplate_properties_; }
   ZoneList<Property*>* properties() const { return properties_; }
   bool fast_elements() const { return fast_elements_; }
   bool may_store_doubles() const { return may_store_doubles_; }
@@ -1786,10 +1792,13 @@ class Property final : public Expression {
     return property_feedback_slot_;
   }
 
-  static LhsKind GetAssignType(Property* property) {
+  static LhsKind GetAssignType(
+      Property* property,
+      HandleDereferenceMode deref_mode =
+          HandleDereferenceMode::kHandleDereferenceAllowed) {
     if (property == NULL) return VARIABLE;
     bool super_access = property->IsSuperAccess();
-    return (property->key()->IsPropertyName())
+    return (property->key()->IsPropertyName(deref_mode))
                ? (super_access ? NAMED_SUPER_PROPERTY : NAMED_PROPERTY)
                : (super_access ? KEYED_SUPER_PROPERTY : KEYED_PROPERTY);
   }
@@ -1904,9 +1913,18 @@ class Call final : public Expression {
   };
 
   // Helpers to determine how to handle the call.
-  CallType GetCallType(Isolate* isolate) const;
-  bool IsUsingCallFeedbackSlot(Isolate* isolate) const;
-  bool IsUsingCallFeedbackICSlot(Isolate* isolate) const;
+  CallType GetCallType(
+      Isolate* isolate,
+      HandleDereferenceMode deref_mode =
+          HandleDereferenceMode::kHandleDereferenceAllowed) const;
+  bool IsUsingCallFeedbackSlot(
+      Isolate* isolate,
+      HandleDereferenceMode deref_mode =
+          HandleDereferenceMode::kHandleDereferenceAllowed) const;
+  bool IsUsingCallFeedbackICSlot(
+      Isolate* isolate,
+      HandleDereferenceMode deref_mode =
+          HandleDereferenceMode::kHandleDereferenceAllowed) const;
 
 #ifdef DEBUG
   // Used to assert that the FullCodeGenerator records the return site.