Chain ScopeInfos together

src/objects.h

 // Copyright 2015 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_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 4373 matching lines @@
   // must be an internalized string.
   int FunctionContextSlotIndex(String* name, VariableMode* mode);
 
   // Lookup support for serialized scope info.  Returns the receiver context
   // slot index if scope has a "this" binding, and the binding is
   // context-allocated.  Otherwise returns a value < 0.
   int ReceiverContextSlotIndex();
 
   FunctionKind function_kind();
 
+  // Returns true if this ScopeInfo is linked to a outer ScopeInfo.
+  bool HasOuterScopeInfo();
+
+  // Return the outer ScopeInfo if present.
+  ScopeInfo* OuterScopeInfo();
+
   static Handle<ScopeInfo> Create(Isolate* isolate, Zone* zone, Scope* scope);
   static Handle<ScopeInfo> CreateGlobalThisBinding(Isolate* isolate);
 
   // Serializes empty scope info.
   static ScopeInfo* Empty(Isolate* isolate);
 
 #ifdef DEBUG
   void Print();
 #endif
 
@@ skipping 53 matching lines @@
   //    context local, so in total this part occupies ContextLocalCount()
   //    slots in the array.
   // 6. RecieverEntryIndex:
   //    If the scope binds a "this" value, one slot is reserved to hold the
   //    context or stack slot index for the variable.
   // 7. FunctionNameEntryIndex:
   //    If the scope belongs to a named function expression this part contains
   //    information about the function variable. It always occupies two array
   //    slots:  a. The name of the function variable.
   //            b. The context or stack slot index for the variable.
+  // 8. OuterScopeInfoEntryIndex:
+  //    The outer scope's ScopeInfo or the hole if there's none.
   int ParameterEntriesIndex();
   int StackLocalFirstSlotIndex();
   int StackLocalEntriesIndex();
   int ContextLocalNameEntriesIndex();
   int ContextGlobalNameEntriesIndex();
   int ContextLocalInfoEntriesIndex();
   int ContextGlobalInfoEntriesIndex();
   int ReceiverEntryIndex();
   int FunctionNameEntryIndex();
+  int OuterScopeInfoEntryIndex();
 
   int Lookup(Handle<String> name, int start, int end, VariableMode* mode,
              VariableLocation* location, InitializationFlag* init_flag,
              MaybeAssignedFlag* maybe_assigned_flag);
 
   // Used for the function name variable for named function expressions, and for
   // the receiver.
   enum VariableAllocationInfo { NONE, STACK, CONTEXT, UNUSED };
 
   // Properties of scopes.
@@ skipping 13 matching lines @@
       : public BitField<VariableAllocationInfo, HasNewTargetField::kNext, 2> {};
   class FunctionVariableMode
       : public BitField<VariableMode, FunctionVariableField::kNext, 3> {};
   class AsmModuleField : public BitField<bool, FunctionVariableMode::kNext, 1> {
   };
   class AsmFunctionField : public BitField<bool, AsmModuleField::kNext, 1> {};
   class HasSimpleParametersField
       : public BitField<bool, AsmFunctionField::kNext, 1> {};
   class FunctionKindField
       : public BitField<FunctionKind, HasSimpleParametersField::kNext, 9> {};
+  class HasOuterScopeInfoField
+      : public BitField<bool, FunctionKindField::kNext, 1> {};
 
   // Properties of variables.
   class VariableModeField : public BitField<VariableMode, 0, 3> {};
   class InitFlagField : public BitField<InitializationFlag, 3, 1> {};
   class MaybeAssignedFlagField : public BitField<MaybeAssignedFlag, 4, 1> {};
 
   friend class ScopeIterator;
 };
 
 
@@ skipping 6659 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_