Introduce an API to force the deletion of a property ignoring...

src/objects.h

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1257 matching lines @@
 
   bool HasProperty(String* name) {
     return GetPropertyAttribute(name) != ABSENT;
   }
 
   // Can cause a GC if it hits an interceptor.
   bool HasLocalProperty(String* name) {
     return GetLocalPropertyAttribute(name) != ABSENT;
   }
 
-  Object* DeleteProperty(String* name);
-  Object* DeleteElement(uint32_t index);
-  Object* DeleteLazyProperty(LookupResult* result, String* name);
+  enum DeleteMode { NORMAL_DELETION, FORCE_DELETION };
+  Object* DeleteProperty(String* name, DeleteMode mode);
+  Object* DeleteElement(uint32_t index, DeleteMode mode);
+  Object* DeleteLazyProperty(LookupResult* result,
+                             String* name,
+                             DeleteMode mode);
 
   // Tests for the fast common case for property enumeration.
   bool IsSimpleEnum();
 
   // Do we want to keep the elements in fast case when increasing the
   // capacity?
   bool ShouldConvertToSlowElements(int new_capacity);
   // Returns true if the backing storage for the slow-case elements of
   // this object takes up nearly as much space as a fast-case backing
   // storage would.  In that case the JSObject should have fast
@@ skipping 221 matching lines @@
   static const int kHeaderSize = kElementsOffset + kPointerSize;
 
   Object* GetElementWithInterceptor(JSObject* receiver, uint32_t index);
 
  private:
   Object* SetElementWithInterceptor(uint32_t index, Object* value);
   Object* SetElementPostInterceptor(uint32_t index, Object* value);
 
   Object* GetElementPostInterceptor(JSObject* receiver, uint32_t index);
 
-  Object* DeletePropertyPostInterceptor(String* name);
+  Object* DeletePropertyPostInterceptor(String* name, DeleteMode mode);
   Object* DeletePropertyWithInterceptor(String* name);
 
-  Object* DeleteElementPostInterceptor(uint32_t index);
+  Object* DeleteElementPostInterceptor(uint32_t index, DeleteMode mode);
   Object* DeleteElementWithInterceptor(uint32_t index);
 
   PropertyAttributes GetPropertyAttributePostInterceptor(JSObject* receiver,
                                                          String* name,
                                                          bool continue_search);
   PropertyAttributes GetPropertyAttributeWithInterceptor(JSObject* receiver,
                                                          String* name,
                                                          bool continue_search);
   PropertyAttributes GetPropertyAttributeWithFailedAccessCheck(
       Object* receiver,
@@ skipping 514 matching lines @@
   // Casting.
   static inline Dictionary* cast(Object* obj);
 
   // Find entry for string key otherwise return -1.
   int FindStringEntry(String* key);
 
   // Find entry for number key otherwise return -1.
   int FindNumberEntry(uint32_t index);
 
   // Delete a property from the dictionary.
-  Object* DeleteProperty(int entry);
+  Object* DeleteProperty(int entry, JSObject::DeleteMode mode);
 
   // Type specific at put (default NONE attributes is used when adding).
   Object* AtStringPut(String* key, Object* value);
   Object* AtNumberPut(uint32_t key, Object* value);
 
   Object* AddStringEntry(String* key, Object* value, PropertyDetails details);
   Object* AddNumberEntry(uint32_t key, Object* value, PropertyDetails details);
 
   // Set an existing entry or add a new one if needed.
   Object* SetOrAddStringEntry(String* key,
@@ skipping 550 matching lines @@
   // Bit positions for bit field.
   static const int kUnused = 0;  // To be used for marking recently used maps.
   static const int kHasNonInstancePrototype = 1;
   static const int kIsHiddenPrototype = 2;
   static const int kHasNamedInterceptor = 3;
   static const int kHasIndexedInterceptor = 4;
   static const int kIsUndetectable = 5;
   static const int kHasInstanceCallHandler = 6;
   static const int kIsAccessCheckNeeded = 7;
 
-  // Bit positions for but field 2
+  // Bit positions for bit field 2
   static const int kNeedsLoading = 0;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
 };
 
 
 // An abstract superclass, a marker class really, for simple structure classes.
 // It doesn't carry much functionality but allows struct classes to me
 // identified in the type system.
@@ skipping 1782 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_