Refactorings only: More uses of "To" template and comment fixes.

Review URL: https://chromiumcodereview.appspot.com/9594018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10932 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -5764,9 +5764,8 @@ MaybeObject* DescriptorArray::CopyInsert(Descriptor* descriptor,
   ASSERT(descriptor->GetDetails().type() != NULL_DESCRIPTOR);
 
   // Ensure the key is a symbol.
-  Object* result;
   { MaybeObject* maybe_result = descriptor->KeyToSymbol();
-    if (!maybe_result->ToObject(&result)) return maybe_result;
+    if (maybe_result->IsFailure()) return maybe_result;
   }
 
   int new_size = 0;
@@ -5801,9 +5800,7 @@ MaybeObject* DescriptorArray::CopyInsert(Descriptor* descriptor,
 
   DescriptorArray* new_descriptors;
   { MaybeObject* maybe_result = Allocate(new_size);
-    if (!maybe_result->To<DescriptorArray>(&new_descriptors)) {
-      return maybe_result;
-    }
+    if (!maybe_result->To(&new_descriptors)) return maybe_result;
   }
 
   DescriptorArray::WhitenessWitness witness(new_descriptors);
@@ -5853,27 +5850,18 @@ MaybeObject* DescriptorArray::CopyInsert(Descriptor* descriptor,
 
 
 MaybeObject* DescriptorArray::RemoveTransitions() {
-  // Remove all transitions and null descriptors. Return a copy of the array
-  // with all transitions removed, or a Failure object if the new array could
-  // not be allocated.
-
-  // Compute the size of the map transition entries to be removed.
+  // Allocate the new descriptor array.
   int new_number_of_descriptors = 0;
   for (int i = 0; i < number_of_descriptors(); i++) {
     if (IsProperty(i)) new_number_of_descriptors++;
   }
-
-  // Allocate the new descriptor array.
   DescriptorArray* new_descriptors;
   { MaybeObject* maybe_result = Allocate(new_number_of_descriptors);
-    if (!maybe_result->To<DescriptorArray>(&new_descriptors)) {
-      return maybe_result;
-    }
+    if (!maybe_result->To(&new_descriptors)) return maybe_result;
   }
 
-  DescriptorArray::WhitenessWitness witness(new_descriptors);
-
   // Copy the content.
+  DescriptorArray::WhitenessWitness witness(new_descriptors);
   int next_descriptor = 0;
   for (int i = 0; i < number_of_descriptors(); i++) {
     if (IsProperty(i)) {
@@ -7574,11 +7562,10 @@ MaybeObject* JSFunction::SetPrototype(Object* value) {
     // Copy the map so this does not affect unrelated functions.
     // Remove map transitions because they point to maps with a
     // different prototype.
-    Object* new_object;
+    Map* new_map;
     { MaybeObject* maybe_new_map = map()->CopyDropTransitions();
-      if (!maybe_new_map->ToObject(&new_object)) return maybe_new_map;
+      if (!maybe_new_map->To(&new_map)) return maybe_new_map;
     }
-    Map* new_map = Map::cast(new_object);
     Heap* heap = new_map->GetHeap();
     set_map(new_map);
     new_map->set_constructor(value);
@@ -7635,12 +7622,12 @@ Context* JSFunction::GlobalContextFromLiterals(FixedArray* literals) {
 MaybeObject* Oddball::Initialize(const char* to_string,
                                  Object* to_number,
                                  byte kind) {
-  Object* symbol;
+  String* symbol;
   { MaybeObject* maybe_symbol =
         Isolate::Current()->heap()->LookupAsciiSymbol(to_string);
-    if (!maybe_symbol->ToObject(&symbol)) return maybe_symbol;
+    if (!maybe_symbol->To(&symbol)) return maybe_symbol;
   }
-  set_to_string(String::cast(symbol));
+  set_to_string(symbol);
   set_to_number(to_number);
   set_kind(kind);
   return this;
@@ -8552,17 +8539,14 @@ MaybeObject* JSObject::SetFastElementsCapacityAndLength(
   ASSERT(!HasExternalArrayElements());
 
   // Allocate a new fast elements backing store.
-  FixedArray* new_elements = NULL;
-  { Object* object;
-    MaybeObject* maybe = heap->AllocateFixedArrayWithHoles(capacity);
-    if (!maybe->ToObject(&object)) return maybe;
-    new_elements = FixedArray::cast(object);
+  FixedArray* new_elements;
+  { MaybeObject* maybe = heap->AllocateFixedArrayWithHoles(capacity);
+    if (!maybe->To(&new_elements)) return maybe;
   }
 
   // Find the new map to use for this object if there is a map change.
   Map* new_map = NULL;
   if (elements()->map() != heap->non_strict_arguments_elements_map()) {
-    Object* object;
     // The resized array has FAST_SMI_ONLY_ELEMENTS if the capacity mode forces
     // it, or if it's allowed and the old elements array contained only SMIs.
     bool has_fast_smi_only_elements =
@@ -8574,8 +8558,7 @@ MaybeObject* JSObject::SetFastElementsCapacityAndLength(
         ? FAST_SMI_ONLY_ELEMENTS
         : FAST_ELEMENTS;
     MaybeObject* maybe = GetElementsTransitionMap(GetIsolate(), elements_kind);
-    if (!maybe->ToObject(&object)) return maybe;
-    new_map = Map::cast(object);
+    if (!maybe->To(&new_map)) return maybe;
   }
 
   FixedArrayBase* old_elements_raw = elements();
@@ -8630,7 +8613,7 @@ MaybeObject* JSObject::SetFastElementsCapacityAndLength(
           MaybeObject* maybe_value_object =
               GetHeap()->AllocateHeapNumber(old_elements->get_scalar(i),
                                             TENURED);
-          if (!maybe_value_object->ToObject(&obj)) return maybe_value_object;
+          if (!maybe_value_object->To(&obj)) return maybe_value_object;
           // Force write barrier. It's not worth trying to exploit
           // elems->GetWriteBarrierMode(), since it requires an
           // AssertNoAllocation stack object that would have to be positioned
@@ -8676,18 +8659,17 @@ MaybeObject* JSObject::SetFastDoubleElementsCapacityAndLength(
   // We should never end in here with a pixel or external array.
   ASSERT(!HasExternalArrayElements());
 
-  Object* obj;
+  FixedDoubleArray* elems;
   { MaybeObject* maybe_obj =
         heap->AllocateUninitializedFixedDoubleArray(capacity);
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
+    if (!maybe_obj->To(&elems)) return maybe_obj;
   }
-  FixedDoubleArray* elems = FixedDoubleArray::cast(obj);
 
+  Map* new_map;
   { MaybeObject* maybe_obj =
         GetElementsTransitionMap(heap->isolate(), FAST_DOUBLE_ELEMENTS);
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
+    if (!maybe_obj->To(&new_map)) return maybe_obj;
   }
-  Map* new_map = Map::cast(obj);
 
   FixedArrayBase* old_elements = elements();
   ElementsKind elements_kind(GetElementsKind());
@@ -8739,11 +8721,8 @@ MaybeObject* JSArray::Initialize(int capacity) {
   if (capacity == 0) {
     new_elements = heap->empty_fixed_array();
   } else {
-    Object* obj;
-    { MaybeObject* maybe_obj = heap->AllocateFixedArrayWithHoles(capacity);
-      if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-    }
-    new_elements = FixedArray::cast(obj);
+    MaybeObject* maybe_obj = heap->AllocateFixedArrayWithHoles(capacity);
+    if (!maybe_obj->To(&new_elements)) return maybe_obj;
   }
   set_elements(new_elements);
   return this;
@@ -8803,7 +8782,7 @@ MaybeObject* Map::PutPrototypeTransition(Object* prototype, Map* map) {
     // Grow array by factor 2 over and above what we need.
     { MaybeObject* maybe_cache =
           GetHeap()->AllocateFixedArray(transitions * 2 * step + header);
-      if (!maybe_cache->To<FixedArray>(&new_cache)) return maybe_cache;
+      if (!maybe_cache->To(&new_cache)) return maybe_cache;
     }
 
     for (int i = 0; i < capacity * step; i++) {
@@ -9306,10 +9285,8 @@ MaybeObject* JSObject::SetFastElement(uint32_t index,
   if (backing_store->map() == GetHeap()->non_strict_arguments_elements_map()) {
     backing_store = FixedArray::cast(backing_store->get(1));
   } else {
-    Object* writable;
     MaybeObject* maybe = EnsureWritableFastElements();
-    if (!maybe->ToObject(&writable)) return maybe;
-    backing_store = FixedArray::cast(writable);
+    if (!maybe->To(&backing_store)) return maybe;
   }
   uint32_t capacity = static_cast<uint32_t>(backing_store->length());
 
@@ -9362,10 +9339,11 @@ MaybeObject* JSObject::SetFastElement(uint32_t index,
   }
   // Change elements kind from SMI_ONLY to generic FAST if necessary.
   if (HasFastSmiOnlyElements() && !value->IsSmi()) {
-    MaybeObject* maybe_new_map = GetElementsTransitionMap(GetIsolate(),
-                                                          FAST_ELEMENTS);
     Map* new_map;
-    if (!maybe_new_map->To<Map>(&new_map)) return maybe_new_map;
+    { MaybeObject* maybe_new_map = GetElementsTransitionMap(GetIsolate(),
+                                                            FAST_ELEMENTS);
+      if (!maybe_new_map->To(&new_map)) return maybe_new_map;
+    }
     set_map(new_map);
     if (FLAG_trace_elements_transitions) {
       PrintElementsTransition(stdout, FAST_SMI_ONLY_ELEMENTS, elements(),
@@ -9374,17 +9352,18 @@ MaybeObject* JSObject::SetFastElement(uint32_t index,
   }
   // Increase backing store capacity if that's been decided previously.
   if (new_capacity != capacity) {
-    Object* new_elements;
+    FixedArray* new_elements;
     SetFastElementsCapacityMode set_capacity_mode =
         value->IsSmi() && HasFastSmiOnlyElements()
             ? kAllowSmiOnlyElements
             : kDontAllowSmiOnlyElements;
-    MaybeObject* maybe =
-        SetFastElementsCapacityAndLength(new_capacity,
-                                         array_length,
-                                         set_capacity_mode);
-    if (!maybe->ToObject(&new_elements)) return maybe;
-    FixedArray::cast(new_elements)->set(index, value);
+    { MaybeObject* maybe =
+          SetFastElementsCapacityAndLength(new_capacity,
+                                           array_length,
+                                           set_capacity_mode);
+      if (!maybe->To(&new_elements)) return maybe;
+    }
+    new_elements->set(index, value);
     return value;
   }
   // Finally, set the new element and length.
@@ -9484,7 +9463,7 @@ MaybeObject* JSObject::SetDictionaryElement(uint32_t index,
     FixedArrayBase* new_dictionary;
     PropertyDetails details = PropertyDetails(attributes, NORMAL);
     MaybeObject* maybe = dictionary->AddNumberEntry(index, value, details);
-    if (!maybe->To<FixedArrayBase>(&new_dictionary)) return maybe;
+    if (!maybe->To(&new_dictionary)) return maybe;
     if (dictionary != SeededNumberDictionary::cast(new_dictionary)) {
       if (is_arguments) {
         elements->set(1, new_dictionary);

src/objects.h

@@ -2506,8 +2506,8 @@ class DescriptorArray: public FixedArray {
   MUST_USE_RESULT MaybeObject* CopyInsert(Descriptor* descriptor,
                                           TransitionFlag transition_flag);
 
-  // Remove all transitions.  Return  a copy of the array with all transitions
-  // removed, or a Failure object if the new array could not be allocated.
+  // Return a copy of the array with all transitions and null descriptors
+  // removed. Return a Failure object in case of an allocation failure.
   MUST_USE_RESULT MaybeObject* RemoveTransitions();
 
   // Sort the instance descriptors by the hash codes of their keys.

src/property.h

@@ -49,11 +49,8 @@ class Descriptor BASE_EMBEDDED {
 
   MUST_USE_RESULT MaybeObject* KeyToSymbol() {
     if (!StringShape(key_).IsSymbol()) {
-      Object* result;
-      { MaybeObject* maybe_result = HEAP->LookupSymbol(key_);
-        if (!maybe_result->ToObject(&result)) return maybe_result;
-      }
-      key_ = String::cast(result);
+      MaybeObject* maybe_result = HEAP->LookupSymbol(key_);
+      if (!maybe_result->To(&key_)) return maybe_result;
     }
     return key_;
   }