Remove the LookupResult IsValid method because it is confusing....

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 3900)
+++ src/objects.cc	(working copy)
@@ -219,7 +219,7 @@
     LookupResult* result,
     String* name,
     PropertyAttributes* attributes) {
-  if (result->IsValid()) {
+  if (result->IsProperty()) {
     switch (result->type()) {
       case CALLBACKS: {
         // Only allow API accessors.
@@ -242,7 +242,7 @@
         // Search ALL_CAN_READ accessors in prototype chain.
         LookupResult r;
         result->holder()->LookupRealNamedPropertyInPrototypes(name, &r);
-        if (r.IsValid()) {
+        if (r.IsProperty()) {
           return GetPropertyWithFailedAccessCheck(receiver,
                                                   &r,
                                                   name,
@@ -255,16 +255,15 @@
         // No access check in GetPropertyAttributeWithInterceptor.
         LookupResult r;
         result->holder()->LookupRealNamedProperty(name, &r);
-        if (r.IsValid()) {
+        if (r.IsProperty()) {
           return GetPropertyWithFailedAccessCheck(receiver,
                                                   &r,
                                                   name,
                                                   attributes);
         }
       }
-      default: {
-        break;
-      }
+      default:
+        UNREACHABLE();
     }
   }
 
@@ -280,7 +279,7 @@
     LookupResult* result,
     String* name,
     bool continue_search) {
-  if (result->IsValid()) {
+  if (result->IsProperty()) {
     switch (result->type()) {
       case CALLBACKS: {
         // Only allow API accessors.
@@ -301,7 +300,7 @@
         // Search ALL_CAN_READ accessors in prototype chain.
         LookupResult r;
         result->holder()->LookupRealNamedPropertyInPrototypes(name, &r);
-        if (r.IsValid()) {
+        if (r.IsProperty()) {
           return GetPropertyAttributeWithFailedAccessCheck(receiver,
                                                            &r,
                                                            name,
@@ -319,7 +318,7 @@
         } else {
           result->holder()->LocalLookupRealNamedProperty(name, &r);
         }
-        if (r.IsValid()) {
+        if (r.IsProperty()) {
           return GetPropertyAttributeWithFailedAccessCheck(receiver,
                                                            &r,
                                                            name,
@@ -328,9 +327,8 @@
         break;
       }
 
-      default: {
-        break;
-      }
+      default:
+        UNREACHABLE();
     }
   }
 
@@ -505,7 +503,7 @@
   // holder will always be the interceptor holder and the search may
   // only continue with a current object just after the interceptor
   // holder in the prototype chain.
-  Object* last = result->IsValid() ? result->holder() : Heap::null_value();
+  Object* last = result->IsProperty() ? result->holder() : Heap::null_value();
   for (Object* current = this; true; current = current->GetPrototype()) {
     if (current->IsAccessCheckNeeded()) {
       // Check if we're allowed to read from the current object. Note
@@ -1463,8 +1461,12 @@
   // Check local property, ignore interceptor.
   LookupResult result;
   LocalLookupRealNamedProperty(name, &result);
-  if (result.IsValid()) return SetProperty(&result, name, value, attributes);
-  // Add real property.
+  if (result.IsFound()) {
+    // An existing property, a map transition or a null descriptor was
+    // found.  Use set property to handle all these cases.
+    return SetProperty(&result, name, value, attributes);
+  }
+  // Add a new real property.
   return AddProperty(name, value, attributes);
 }
 
@@ -1696,8 +1698,8 @@
        pt != Heap::null_value();
        pt = pt->GetPrototype()) {
     JSObject::cast(pt)->LocalLookupRealNamedProperty(name, result);
-    if (result->IsValid()) {
-      if (!result->IsTransitionType() && result->IsReadOnly()) {
+    if (result->IsProperty()) {
+      if (result->IsReadOnly()) {
         result->NotFound();
         return;
       }
@@ -1758,7 +1760,11 @@
 
   if (HasFastProperties()) {
     LookupInDescriptor(name, result);
-    if (result->IsValid()) {
+    if (result->IsFound()) {
+      // A property, a map transition or a null descriptor was found.
+      // We return all of these result types because
+      // LocalLookupRealNamedProperty is used when setting properties
+      // where map transitions and null descriptors are handled.
       ASSERT(result->holder() == this && result->type() != NORMAL);
       // Disallow caching for uninitialized constants. These can only
       // occur as fields.
@@ -1808,16 +1814,7 @@
        pt != Heap::null_value();
        pt = JSObject::cast(pt)->GetPrototype()) {
     JSObject::cast(pt)->LocalLookupRealNamedProperty(name, result);
-    if (result->IsValid()) {
-      switch (result->type()) {
-        case NORMAL:
-        case FIELD:
-        case CONSTANT_FUNCTION:
-        case CALLBACKS:
-          return;
-        default: break;
-      }
-    }
+    if (result->IsProperty() && (result->type() != INTERCEPTOR)) return;
   }
   result->NotFound();
 }
@@ -1903,14 +1900,15 @@
     // accessor that wants to handle the property.
     LookupResult accessor_result;
     LookupCallbackSetterInPrototypes(name, &accessor_result);
-    if (accessor_result.IsValid()) {
+    if (accessor_result.IsProperty()) {
       return SetPropertyWithCallback(accessor_result.GetCallbackObject(),
                                      name,
                                      value,
                                      accessor_result.holder());
     }
   }
-  if (result->IsNotFound()) {
+  if (!result->IsFound()) {
+    // Neither properties nor transitions found.
     return AddProperty(name, value, attributes);
   }
   if (!result->IsLoaded()) {
@@ -1972,15 +1970,12 @@
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc;
-  // ADDED TO CLONE
-  LookupResult result_struct;
-  LocalLookup(name, &result_struct);
-  LookupResult* result = &result_struct;
-  // END ADDED TO CLONE
+  LookupResult result;
+  LocalLookup(name, &result);
   // Check access rights if needed.
   if (IsAccessCheckNeeded()
-    && !Top::MayNamedAccess(this, name, v8::ACCESS_SET)) {
-    return SetPropertyWithFailedAccessCheck(result, name, value);
+      && !Top::MayNamedAccess(this, name, v8::ACCESS_SET)) {
+    return SetPropertyWithFailedAccessCheck(&result, name, value);
   }
 
   if (IsJSGlobalProxy()) {
@@ -1994,33 +1989,34 @@
   }
 
   // Check for accessor in prototype chain removed here in clone.
-  if (result->IsNotFound()) {
+  if (!result.IsFound()) {
+    // Neither properties nor transitions found.
     return AddProperty(name, value, attributes);
   }
-  if (!result->IsLoaded()) {
-    return SetLazyProperty(result, name, value, attributes);
+  if (!result.IsLoaded()) {
+    return SetLazyProperty(&result, name, value, attributes);
   }
   PropertyDetails details = PropertyDetails(attributes, NORMAL);
 
   // Check of IsReadOnly removed from here in clone.
-  switch (result->type()) {
+  switch (result.type()) {
     case NORMAL:
       return SetNormalizedProperty(name, value, details);
     case FIELD:
-      return FastPropertyAtPut(result->GetFieldIndex(), value);
+      return FastPropertyAtPut(result.GetFieldIndex(), value);
     case MAP_TRANSITION:
-      if (attributes == result->GetAttributes()) {
+      if (attributes == result.GetAttributes()) {
         // Only use map transition if the attributes match.
-        return AddFastPropertyUsingMap(result->GetTransitionMap(),
+        return AddFastPropertyUsingMap(result.GetTransitionMap(),
                                        name,
                                        value);
       }
       return ConvertDescriptorToField(name, value, attributes);
     case CONSTANT_FUNCTION:
       // Only replace the function if necessary.
-      if (value == result->GetConstantFunction()) return value;
+      if (value == result.GetConstantFunction()) return value;
       // Preserve the attributes of this existing property.
-      attributes = result->GetAttributes();
+      attributes = result.GetAttributes();
       return ConvertDescriptorToField(name, value, attributes);
     case CALLBACKS:
     case INTERCEPTOR:
@@ -2136,7 +2132,7 @@
                                                      name,
                                                      continue_search);
   }
-  if (result->IsValid()) {
+  if (result->IsProperty()) {
     switch (result->type()) {
       case NORMAL:  // fall through
       case FIELD:
@@ -2146,13 +2142,8 @@
       case INTERCEPTOR:
         return result->holder()->
           GetPropertyAttributeWithInterceptor(receiver, name, continue_search);
-      case MAP_TRANSITION:
-      case CONSTANT_TRANSITION:
-      case NULL_DESCRIPTOR:
-        return ABSENT;
       default:
         UNREACHABLE();
-        break;
     }
   }
   return ABSENT;
@@ -2325,7 +2316,7 @@
   // Check local property, ignore interceptor.
   LookupResult result;
   LocalLookupRealNamedProperty(name, &result);
-  if (!result.IsValid()) return Heap::true_value();
+  if (!result.IsProperty()) return Heap::true_value();
 
   // Normalize object if needed.
   Object* obj = NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0);
@@ -2509,7 +2500,7 @@
   } else {
     LookupResult result;
     LocalLookup(name, &result);
-    if (!result.IsValid()) return Heap::true_value();
+    if (!result.IsProperty()) return Heap::true_value();
     // Ignore attributes if forcing a deletion.
     if (result.IsDontDelete() && mode != FORCE_DELETION) {
       return Heap::false_value();
@@ -2744,7 +2735,7 @@
        current != Heap::null_value();
        current = JSObject::cast(current)->GetPrototype()) {
     JSObject::cast(current)->LocalLookup(name, result);
-    if (result->IsValid() && !result->IsTransitionType()) return;
+    if (result->IsProperty()) return;
   }
   result->NotFound();
 }
@@ -2756,7 +2747,7 @@
        current != Heap::null_value();
        current = JSObject::cast(current)->GetPrototype()) {
     JSObject::cast(current)->LocalLookupRealNamedProperty(name, result);
-    if (result->IsValid() && result->type() == CALLBACKS) return;
+    if (result->IsProperty() && result->type() == CALLBACKS) return;
   }
   result->NotFound();
 }
@@ -2786,7 +2777,7 @@
   // cause security problems.
   LookupResult callback_result;
   LookupCallback(name, &callback_result);
-  if (callback_result.IsValid()) {
+  if (callback_result.IsFound()) {
     Object* obj = callback_result.GetCallbackObject();
     if (obj->IsAccessorInfo() &&
         AccessorInfo::cast(obj)->prohibits_overwriting()) {
@@ -2837,7 +2828,7 @@
     // Lookup the name.
     LookupResult result;
     LocalLookup(name, &result);
-    if (result.IsValid()) {
+    if (result.IsProperty()) {
       if (result.IsReadOnly()) return Heap::undefined_value();
       if (result.type() == CALLBACKS) {
         Object* obj = result.GetCallbackObject();
@@ -2959,7 +2950,7 @@
          obj = JSObject::cast(obj)->GetPrototype()) {
       LookupResult result;
       JSObject::cast(obj)->LocalLookup(name, &result);
-      if (result.IsValid()) {
+      if (result.IsProperty()) {
         if (result.IsReadOnly()) return Heap::undefined_value();
         if (result.type() == CALLBACKS) {
           Object* obj = result.GetCallbackObject();
@@ -4851,7 +4842,7 @@
       LookupResult result;
       String* name = GetThisPropertyAssignmentName(i);
       js_object->LocalLookupRealNamedProperty(name, &result);
-      if (result.IsValid() && result.type() == CALLBACKS) {
+      if (result.IsProperty() && result.type() == CALLBACKS) {
         return false;
       }
     }
@@ -6252,7 +6243,9 @@
   // Check local property in holder, ignore interceptor.
   LookupResult result;
   LocalLookupRealNamedProperty(name, &result);
-  if (result.IsValid()) return GetProperty(receiver, &result, name, attributes);
+  if (result.IsProperty()) {
+    return GetProperty(receiver, &result, name, attributes);
+  }
   // Continue searching via the prototype chain.
   Object* pt = GetPrototype();
   *attributes = ABSENT;
@@ -6268,8 +6261,10 @@
   // Check local property in holder, ignore interceptor.
   LookupResult result;
   LocalLookupRealNamedProperty(name, &result);
-  if (!result.IsValid()) return Heap::undefined_value();
-  return GetProperty(receiver, &result, name, attributes);
+  if (result.IsProperty()) {
+    return GetProperty(receiver, &result, name, attributes);
+  }
+  return Heap::undefined_value();
 }
 
 
@@ -6321,24 +6316,7 @@
 
   LookupResult result;
   LocalLookupRealNamedProperty(key, &result);
-  if (result.IsValid()) {
-    switch (result.type()) {
-      case NORMAL:    // fall through.
-      case FIELD:     // fall through.
-      case CALLBACKS:  // fall through.
-      case CONSTANT_FUNCTION:
-        return true;
-      case INTERCEPTOR:
-      case MAP_TRANSITION:
-      case CONSTANT_TRANSITION:
-      case NULL_DESCRIPTOR:
-        return false;
-      default:
-        UNREACHABLE();
-    }
-  }
-
-  return false;
+  return result.IsProperty() && (result.type() != INTERCEPTOR);
 }
 
 
@@ -6400,7 +6378,7 @@
 
   LookupResult result;
   LocalLookupRealNamedProperty(key, &result);
-  return result.IsValid() && (result.type() == CALLBACKS);
+  return result.IsProperty() && (result.type() == CALLBACKS);
 }