AIX: Fix 'may be used uninitialized' compiler errors

src/heap/heap.cc

 // Copyright 2012 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.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 1050 matching lines @@
         for (auto& chunk : *reservation) {
           AllocationResult allocation;
           int size = chunk.size;
           DCHECK_LE(size, MemoryAllocator::PageAreaSize(
                               static_cast<AllocationSpace>(space)));
           if (space == NEW_SPACE) {
             allocation = new_space()->AllocateRawUnaligned(size);
           } else {
             allocation = paged_space(space)->AllocateRawUnaligned(size);
           }
-          HeapObject* free_space;
+          HeapObject* free_space = nullptr;
           if (allocation.To(&free_space)) {
             // Mark with a free list node, in case we have a GC before
             // deserializing.
             Address free_space_address = free_space->address();
             CreateFillerObjectAt(free_space_address, size);
             DCHECK(space < Serializer::kNumberOfPreallocatedSpaces);
             chunk.start = free_space_address;
             chunk.end = free_space_address + size;
           } else {
             perform_gc = true;
@@ skipping 1494 matching lines @@
                    Map::Counter::encode(Map::kRetainingCounterStart);
   reinterpret_cast<Map*>(result)->set_bit_field3(bit_field3);
   reinterpret_cast<Map*>(result)->set_weak_cell_cache(Smi::FromInt(0));
   return result;
 }
 
 
 AllocationResult Heap::AllocateMap(InstanceType instance_type,
                                    int instance_size,
                                    ElementsKind elements_kind) {
-  HeapObject* result;
+  HeapObject* result = nullptr;
   AllocationResult allocation = AllocateRaw(Map::kSize, MAP_SPACE, MAP_SPACE);
   if (!allocation.To(&result)) return allocation;
 
   result->set_map_no_write_barrier(meta_map());
   Map* map = Map::cast(result);
   map->set_instance_type(instance_type);
   map->set_prototype(null_value(), SKIP_WRITE_BARRIER);
   map->set_constructor_or_backpointer(null_value(), SKIP_WRITE_BARRIER);
   map->set_instance_size(instance_size);
   map->clear_unused();
@@ skipping 18 matching lines @@
                    Map::Counter::encode(Map::kRetainingCounterStart);
   map->set_bit_field3(bit_field3);
   map->set_elements_kind(elements_kind);
 
   return map;
 }
 
 
 AllocationResult Heap::AllocateFillerObject(int size, bool double_align,
                                             AllocationSpace space) {
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   {
     AllocationAlignment align = double_align ? kDoubleAligned : kWordAligned;
     AllocationResult allocation = AllocateRaw(size, space, space, align);
     if (!allocation.To(&obj)) return allocation;
   }
 #ifdef DEBUG
   MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
   DCHECK(chunk->owner()->identity() == space);
 #endif
   CreateFillerObjectAt(obj->address(), size);
@@ skipping 23 matching lines @@
 const Heap::StructTable Heap::struct_table[] = {
 #define STRUCT_TABLE_ELEMENT(NAME, Name, name)        \
   { NAME##_TYPE, Name::kSize, k##Name##MapRootIndex } \
   ,
     STRUCT_LIST(STRUCT_TABLE_ELEMENT)
 #undef STRUCT_TABLE_ELEMENT
 };
 
 
 bool Heap::CreateInitialMaps() {
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   {
     AllocationResult allocation = AllocatePartialMap(MAP_TYPE, Map::kSize);
     if (!allocation.To(&obj)) return false;
   }
   // Map::cast cannot be used due to uninitialized map field.
   Map* new_meta_map = reinterpret_cast<Map*>(obj);
   set_meta_map(new_meta_map);
   new_meta_map->set_map(new_meta_map);
 
   {  // Partial map allocation
@@ skipping 215 matching lines @@
 #undef ALLOCATE_VARSIZE_MAP
 #undef ALLOCATE_MAP
   }
 
   {  // Empty arrays
     {
       ByteArray* byte_array;
       if (!AllocateByteArray(0, TENURED).To(&byte_array)) return false;
       set_empty_byte_array(byte_array);
 
-      BytecodeArray* bytecode_array;
+      BytecodeArray* bytecode_array = nullptr;
       AllocationResult allocation =
           AllocateBytecodeArray(0, nullptr, 0, 0, empty_fixed_array());
       if (!allocation.To(&bytecode_array)) {
         return false;
       }
       set_empty_bytecode_array(bytecode_array);
     }
 
 #define ALLOCATE_EMPTY_FIXED_TYPED_ARRAY(Type, type, TYPE, ctype, size) \
   {                                                                     \
@@ skipping 13 matching lines @@
 
 AllocationResult Heap::AllocateHeapNumber(double value, MutableMode mode,
                                           PretenureFlag pretenure) {
   // Statically ensure that it is safe to allocate heap numbers in paged
   // spaces.
   int size = HeapNumber::kSize;
   STATIC_ASSERT(HeapNumber::kSize <= Page::kMaxRegularHeapObjectSize);
 
   AllocationSpace space = SelectSpace(size, pretenure);
 
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation =
         AllocateRaw(size, space, OLD_SPACE, kDoubleUnaligned);
     if (!allocation.To(&result)) return allocation;
   }
 
   Map* map = mode == MUTABLE ? mutable_heap_number_map() : heap_number_map();
   HeapObject::cast(result)->set_map_no_write_barrier(map);
   HeapNumber::cast(result)->set_value(value);
   return result;
 }
 
 #define SIMD_ALLOCATE_DEFINITION(TYPE, Type, type, lane_count, lane_type) \
   AllocationResult Heap::Allocate##Type(lane_type lanes[lane_count],      \
                                         PretenureFlag pretenure) {        \
     int size = Type::kSize;                                               \
     STATIC_ASSERT(Type::kSize <= Page::kMaxRegularHeapObjectSize);        \
                                                                           \
     AllocationSpace space = SelectSpace(size, pretenure);                 \
                                                                           \
-    HeapObject* result;                                                   \
+    HeapObject* result = nullptr;                                         \
     {                                                                     \
       AllocationResult allocation =                                       \
           AllocateRaw(size, space, OLD_SPACE, kSimd128Unaligned);         \
       if (!allocation.To(&result)) return allocation;                     \
     }                                                                     \
                                                                           \
     result->set_map_no_write_barrier(type##_map());                       \
     Type* instance = Type::cast(result);                                  \
     for (int i = 0; i < lane_count; i++) {                                \
       instance->set_lane(i, lanes[i]);                                    \
     }                                                                     \
     return result;                                                        \
   }
 SIMD128_TYPES(SIMD_ALLOCATE_DEFINITION)
 #undef SIMD_ALLOCATE_DEFINITION
 
 
 AllocationResult Heap::AllocateCell(Object* value) {
   int size = Cell::kSize;
   STATIC_ASSERT(Cell::kSize <= Page::kMaxRegularHeapObjectSize);
 
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, OLD_SPACE, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
   result->set_map_no_write_barrier(cell_map());
   Cell::cast(result)->set_value(value);
   return result;
 }
 
 
 AllocationResult Heap::AllocatePropertyCell() {
   int size = PropertyCell::kSize;
   STATIC_ASSERT(PropertyCell::kSize <= Page::kMaxRegularHeapObjectSize);
 
-  HeapObject* result;
+  HeapObject* result = nullptr;
   AllocationResult allocation = AllocateRaw(size, OLD_SPACE, OLD_SPACE);
   if (!allocation.To(&result)) return allocation;
 
   result->set_map_no_write_barrier(global_property_cell_map());
   PropertyCell* cell = PropertyCell::cast(result);
   cell->set_dependent_code(DependentCode::cast(empty_fixed_array()),
                            SKIP_WRITE_BARRIER);
   cell->set_property_details(PropertyDetails(Smi::FromInt(0)));
   cell->set_value(the_hole_value());
   return result;
 }
 
 
 AllocationResult Heap::AllocateWeakCell(HeapObject* value) {
   int size = WeakCell::kSize;
   STATIC_ASSERT(WeakCell::kSize <= Page::kMaxRegularHeapObjectSize);
-  HeapObject* result = NULL;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, OLD_SPACE, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
   result->set_map_no_write_barrier(weak_cell_map());
   WeakCell::cast(result)->initialize(value);
   WeakCell::cast(result)->clear_next(this);
   return result;
 }
 
@@ skipping 448 matching lines @@
   return FixedTypedArrayBase::cast(
       roots_[RootIndexForEmptyFixedTypedArray(map->elements_kind())]);
 }
 
 
 AllocationResult Heap::AllocateForeign(Address address,
                                        PretenureFlag pretenure) {
   // Statically ensure that it is safe to allocate foreigns in paged spaces.
   STATIC_ASSERT(Foreign::kSize <= Page::kMaxRegularHeapObjectSize);
   AllocationSpace space = (pretenure == TENURED) ? OLD_SPACE : NEW_SPACE;
-  Foreign* result;
+  Foreign* result = nullptr;
   AllocationResult allocation = Allocate(foreign_map(), space);
   if (!allocation.To(&result)) return allocation;
   result->set_foreign_address(address);
   return result;
 }
 
 
 AllocationResult Heap::AllocateByteArray(int length, PretenureFlag pretenure) {
   if (length < 0 || length > ByteArray::kMaxLength) {
     v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true);
   }
   int size = ByteArray::SizeFor(length);
   AllocationSpace space = SelectSpace(size, pretenure);
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   result->set_map_no_write_barrier(byte_array_map());
   ByteArray::cast(result)->set_length(length);
   return result;
 }
 
 
 AllocationResult Heap::AllocateBytecodeArray(int length,
                                              const byte* const raw_bytecodes,
                                              int frame_size,
                                              int parameter_count,
                                              FixedArray* constant_pool) {
   if (length < 0 || length > BytecodeArray::kMaxLength) {
     v8::internal::Heap::FatalProcessOutOfMemory("invalid array length", true);
   }
   // Bytecode array is pretenured, so constant pool array should be to.
   DCHECK(!InNewSpace(constant_pool));
 
   int size = BytecodeArray::SizeFor(length);
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, OLD_SPACE, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   result->set_map_no_write_barrier(bytecode_array_map());
   BytecodeArray* instance = BytecodeArray::cast(result);
   instance->set_length(length);
   instance->set_frame_size(frame_size);
   instance->set_parameter_count(parameter_count);
@@ skipping 166 matching lines @@
     profiler->UpdateObjectSizeEvent(object->address(), object->Size());
   }
 }
 
 
 AllocationResult Heap::AllocateFixedTypedArrayWithExternalPointer(
     int length, ExternalArrayType array_type, void* external_pointer,
     PretenureFlag pretenure) {
   int size = FixedTypedArrayBase::kHeaderSize;
   AllocationSpace space = SelectSpace(size, pretenure);
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   result->set_map_no_write_barrier(MapForFixedTypedArray(array_type));
   FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(result);
   elements->set_base_pointer(Smi::FromInt(0), SKIP_WRITE_BARRIER);
   elements->set_external_pointer(external_pointer, SKIP_WRITE_BARRIER);
   elements->set_length(length);
@@ skipping 24 matching lines @@
                                                ExternalArrayType array_type,
                                                bool initialize,
                                                PretenureFlag pretenure) {
   int element_size;
   ElementsKind elements_kind;
   ForFixedTypedArray(array_type, &element_size, &elements_kind);
   int size = OBJECT_POINTER_ALIGN(length * element_size +
                                   FixedTypedArrayBase::kDataOffset);
   AllocationSpace space = SelectSpace(size, pretenure);
 
-  HeapObject* object;
+  HeapObject* object = nullptr;
   AllocationResult allocation = AllocateRaw(
       size, space, OLD_SPACE,
       array_type == kExternalFloat64Array ? kDoubleAligned : kWordAligned);
   if (!allocation.To(&object)) return allocation;
 
   object->set_map_no_write_barrier(MapForFixedTypedArray(array_type));
   FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(object);
   elements->set_base_pointer(elements, SKIP_WRITE_BARRIER);
   elements->set_external_pointer(
       ExternalReference::fixed_typed_array_base_data_offset().address(),
       SKIP_WRITE_BARRIER);
   elements->set_length(length);
   if (initialize) memset(elements->DataPtr(), 0, elements->DataSize());
   return elements;
 }
 
 
 AllocationResult Heap::AllocateCode(int object_size, bool immovable) {
   DCHECK(IsAligned(static_cast<intptr_t>(object_size), kCodeAlignment));
   AllocationResult allocation =
       AllocateRaw(object_size, CODE_SPACE, CODE_SPACE);
 
-  HeapObject* result;
+  HeapObject* result = nullptr;
   if (!allocation.To(&result)) return allocation;
 
   if (immovable) {
     Address address = result->address();
     // Code objects which should stay at a fixed address are allocated either
     // in the first page of code space (objects on the first page of each space
     // are never moved) or in large object space.
     if (!code_space_->FirstPage()->Contains(address) &&
         MemoryChunk::FromAddress(address)->owner()->identity() != LO_SPACE) {
       // Discard the first code allocation, which was on a page where it could
@@ skipping 13 matching lines @@
          object_size <= code_space()->AreaSize());
   code->set_gc_metadata(Smi::FromInt(0));
   code->set_ic_age(global_ic_age_);
   return code;
 }
 
 
 AllocationResult Heap::CopyCode(Code* code) {
   AllocationResult allocation;
 
-  HeapObject* result = NULL;
+  HeapObject* result = nullptr;
   // Allocate an object the same size as the code object.
   int obj_size = code->Size();
   allocation = AllocateRaw(obj_size, CODE_SPACE, CODE_SPACE);
   if (!allocation.To(&result)) return allocation;
 
   // Copy code object.
   Address old_addr = code->address();
   Address new_addr = result->address();
   CopyBlock(new_addr, old_addr, obj_size);
   Code* new_code = Code::cast(result);
 
   // Relocate the copy.
   DCHECK(IsAligned(bit_cast<intptr_t>(new_code->address()), kCodeAlignment));
   DCHECK(isolate_->code_range() == NULL || !isolate_->code_range()->valid() ||
          isolate_->code_range()->contains(code->address()) ||
          obj_size <= code_space()->AreaSize());
   new_code->Relocate(new_addr - old_addr);
   return new_code;
 }
 
 
 AllocationResult Heap::CopyCode(Code* code, Vector<byte> reloc_info) {
   // Allocate ByteArray before the Code object, so that we do not risk
   // leaving uninitialized Code object (and breaking the heap).
-  ByteArray* reloc_info_array;
+  ByteArray* reloc_info_array = nullptr;
   {
     AllocationResult allocation =
         AllocateByteArray(reloc_info.length(), TENURED);
     if (!allocation.To(&reloc_info_array)) return allocation;
   }
 
   int new_body_size = RoundUp(code->instruction_size(), kObjectAlignment);
 
   int new_obj_size = Code::SizeFor(new_body_size);
 
   Address old_addr = code->address();
 
   size_t relocation_offset =
       static_cast<size_t>(code->instruction_end() - old_addr);
 
-  HeapObject* result;
+  HeapObject* result = nullptr;
   AllocationResult allocation =
       AllocateRaw(new_obj_size, CODE_SPACE, CODE_SPACE);
   if (!allocation.To(&result)) return allocation;
 
   // Copy code object.
   Address new_addr = result->address();
 
   // Copy header and instructions.
   CopyBytes(new_addr, old_addr, relocation_offset);
 
@@ skipping 34 matching lines @@
                                 AllocationSite* allocation_site) {
   DCHECK(gc_state_ == NOT_IN_GC);
   DCHECK(map->instance_type() != MAP_TYPE);
   // If allocation failures are disallowed, we may allocate in a different
   // space when new space is full and the object is not a large object.
   AllocationSpace retry_space = (space != NEW_SPACE) ? space : OLD_SPACE;
   int size = map->instance_size();
   if (allocation_site != NULL) {
     size += AllocationMemento::kSize;
   }
-  HeapObject* result;
+  HeapObject* result = nullptr;
   AllocationResult allocation = AllocateRaw(size, space, retry_space);
   if (!allocation.To(&result)) return allocation;
   // No need for write barrier since object is white and map is in old space.
   result->set_map_no_write_barrier(map);
   if (allocation_site != NULL) {
     AllocationMemento* alloc_memento = reinterpret_cast<AllocationMemento*>(
         reinterpret_cast<Address>(result) + map->instance_size());
     InitializeAllocationMemento(alloc_memento, allocation_site);
   }
   return result;
@@ skipping 41 matching lines @@
   // AllocateGlobalObject to be properly initialized.
   DCHECK(map->instance_type() != JS_GLOBAL_OBJECT_TYPE);
   DCHECK(map->instance_type() != JS_BUILTINS_OBJECT_TYPE);
 
   // Allocate the backing storage for the properties.
   FixedArray* properties = empty_fixed_array();
 
   // Allocate the JSObject.
   int size = map->instance_size();
   AllocationSpace space = SelectSpace(size, pretenure);
-  JSObject* js_obj;
+  JSObject* js_obj = nullptr;
   AllocationResult allocation = Allocate(map, space, allocation_site);
   if (!allocation.To(&js_obj)) return allocation;
 
   // Initialize the JSObject.
   InitializeJSObjectFromMap(js_obj, properties, map);
   DCHECK(js_obj->HasFastElements() || js_obj->HasFixedTypedArrayElements());
   return js_obj;
 }
 
 
 AllocationResult Heap::AllocateJSObject(JSFunction* constructor,
                                         PretenureFlag pretenure,
                                         AllocationSite* allocation_site) {
   DCHECK(constructor->has_initial_map());
 
   // Allocate the object based on the constructors initial map.
   AllocationResult allocation = AllocateJSObjectFromMap(
       constructor->initial_map(), pretenure, allocation_site);
 #ifdef DEBUG
   // Make sure result is NOT a global object if valid.
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   DCHECK(!allocation.To(&obj) || !obj->IsGlobalObject());
 #endif
   return allocation;
 }
 
 
 AllocationResult Heap::CopyJSObject(JSObject* source, AllocationSite* site) {
   // Make the clone.
   Map* map = source->map();
 
   // We can only clone normal objects or arrays. Copying anything else
   // will break invariants.
   CHECK(map->instance_type() == JS_OBJECT_TYPE ||
         map->instance_type() == JS_ARRAY_TYPE);
 
   int object_size = map->instance_size();
-  HeapObject* clone;
+  HeapObject* clone = nullptr;
 
   DCHECK(site == NULL || AllocationSite::CanTrack(map->instance_type()));
 
   WriteBarrierMode wb_mode = UPDATE_WRITE_BARRIER;
 
   // If we're forced to always allocate, we use the general allocation
   // functions which may leave us with an object in old space.
   if (always_allocate()) {
     {
       AllocationResult allocation =
@@ skipping 50 matching lines @@
       InitializeAllocationMemento(alloc_memento, site);
     }
   }
 
   SLOW_DCHECK(JSObject::cast(clone)->GetElementsKind() ==
               source->GetElementsKind());
   FixedArrayBase* elements = FixedArrayBase::cast(source->elements());
   FixedArray* properties = FixedArray::cast(source->properties());
   // Update elements if necessary.
   if (elements->length() > 0) {
-    FixedArrayBase* elem;
+    FixedArrayBase* elem = nullptr;
     {
       AllocationResult allocation;
       if (elements->map() == fixed_cow_array_map()) {
         allocation = FixedArray::cast(elements);
       } else if (source->HasFastDoubleElements()) {
         allocation = CopyFixedDoubleArray(FixedDoubleArray::cast(elements));
       } else {
         allocation = CopyFixedArray(FixedArray::cast(elements));
       }
       if (!allocation.To(&elem)) return allocation;
     }
     JSObject::cast(clone)->set_elements(elem, wb_mode);
   }
   // Update properties if necessary.
   if (properties->length() > 0) {
-    FixedArray* prop;
+    FixedArray* prop = nullptr;
     {
       AllocationResult allocation = CopyFixedArray(properties);
       if (!allocation.To(&prop)) return allocation;
     }
     JSObject::cast(clone)->set_properties(prop, wb_mode);
   }
   // Return the new clone.
   return clone;
 }
 
@@ skipping 57 matching lines @@
   if (is_one_byte) {
     map = one_byte_internalized_string_map();
     size = SeqOneByteString::SizeFor(chars);
   } else {
     map = internalized_string_map();
     size = SeqTwoByteString::SizeFor(chars);
   }
   AllocationSpace space = SelectSpace(size, TENURED);
 
   // Allocate string.
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   result->set_map_no_write_barrier(map);
   // Set length and hash fields of the allocated string.
   String* answer = String::cast(result);
   answer->set_length(chars);
   answer->set_hash_field(hash_field);
@@ skipping 21 matching lines @@
 
 
 AllocationResult Heap::AllocateRawOneByteString(int length,
                                                 PretenureFlag pretenure) {
   DCHECK_LE(0, length);
   DCHECK_GE(String::kMaxLength, length);
   int size = SeqOneByteString::SizeFor(length);
   DCHECK(size <= SeqOneByteString::kMaxSize);
   AllocationSpace space = SelectSpace(size, pretenure);
 
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   // Partially initialize the object.
   result->set_map_no_write_barrier(one_byte_string_map());
   String::cast(result)->set_length(length);
   String::cast(result)->set_hash_field(String::kEmptyHashField);
   DCHECK_EQ(size, HeapObject::cast(result)->Size());
 
   return result;
 }
 
 
 AllocationResult Heap::AllocateRawTwoByteString(int length,
                                                 PretenureFlag pretenure) {
   DCHECK_LE(0, length);
   DCHECK_GE(String::kMaxLength, length);
   int size = SeqTwoByteString::SizeFor(length);
   DCHECK(size <= SeqTwoByteString::kMaxSize);
   AllocationSpace space = SelectSpace(size, pretenure);
 
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
   // Partially initialize the object.
   result->set_map_no_write_barrier(string_map());
   String::cast(result)->set_length(length);
   String::cast(result)->set_hash_field(String::kEmptyHashField);
   DCHECK_EQ(size, HeapObject::cast(result)->Size());
   return result;
 }
 
 
 AllocationResult Heap::AllocateEmptyFixedArray() {
   int size = FixedArray::SizeFor(0);
-  HeapObject* result;
+  HeapObject* result = nullptr;
   {
     AllocationResult allocation = AllocateRaw(size, OLD_SPACE, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
   // Initialize the object.
   result->set_map_no_write_barrier(fixed_array_map());
   FixedArray::cast(result)->set_length(0);
   return result;
 }
 
 
 AllocationResult Heap::CopyAndTenureFixedCOWArray(FixedArray* src) {
   if (!InNewSpace(src)) {
     return src;
   }
 
   int len = src->length();
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   {
     AllocationResult allocation = AllocateRawFixedArray(len, TENURED);
     if (!allocation.To(&obj)) return allocation;
   }
   obj->set_map_no_write_barrier(fixed_array_map());
   FixedArray* result = FixedArray::cast(obj);
   result->set_length(len);
 
   // Copy the content.
   DisallowHeapAllocation no_gc;
@@ skipping 12 matching lines @@
     ExternalArrayType array_type) {
   return AllocateFixedTypedArray(0, array_type, false, TENURED);
 }
 
 
 AllocationResult Heap::CopyFixedArrayAndGrow(FixedArray* src, int grow_by,
                                              PretenureFlag pretenure) {
   int old_len = src->length();
   int new_len = old_len + grow_by;
   DCHECK(new_len >= old_len);
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   {
     AllocationResult allocation = AllocateRawFixedArray(new_len, pretenure);
     if (!allocation.To(&obj)) return allocation;
   }
   obj->set_map_no_write_barrier(fixed_array_map());
   FixedArray* result = FixedArray::cast(obj);
   result->set_length(new_len);
 
   // Copy the content.
   DisallowHeapAllocation no_gc;
   WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
   for (int i = 0; i < old_len; i++) result->set(i, src->get(i), mode);
   MemsetPointer(result->data_start() + old_len, undefined_value(), grow_by);
   return result;
 }
 
 
 AllocationResult Heap::CopyFixedArrayWithMap(FixedArray* src, Map* map) {
   int len = src->length();
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   {
     AllocationResult allocation = AllocateRawFixedArray(len, NOT_TENURED);
     if (!allocation.To(&obj)) return allocation;
   }
   if (InNewSpace(obj)) {
     obj->set_map_no_write_barrier(map);
     CopyBlock(obj->address() + kPointerSize, src->address() + kPointerSize,
               FixedArray::SizeFor(len) - kPointerSize);
     return obj;
   }
   obj->set_map_no_write_barrier(map);
   FixedArray* result = FixedArray::cast(obj);
   result->set_length(len);
 
   // Copy the content.
   DisallowHeapAllocation no_gc;
   WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
   for (int i = 0; i < len; i++) result->set(i, src->get(i), mode);
   return result;
 }
 
 
 AllocationResult Heap::CopyFixedDoubleArrayWithMap(FixedDoubleArray* src,
                                                    Map* map) {
   int len = src->length();
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   {
     AllocationResult allocation = AllocateRawFixedDoubleArray(len, NOT_TENURED);
     if (!allocation.To(&obj)) return allocation;
   }
   obj->set_map_no_write_barrier(map);
   CopyBlock(obj->address() + FixedDoubleArray::kLengthOffset,
             src->address() + FixedDoubleArray::kLengthOffset,
             FixedDoubleArray::SizeFor(len) - FixedDoubleArray::kLengthOffset);
   return obj;
 }
@@ skipping 34 matching lines @@
 
 
 AllocationResult Heap::AllocateFixedArray(int length, PretenureFlag pretenure) {
   return AllocateFixedArrayWithFiller(length, pretenure, undefined_value());
 }
 
 
 AllocationResult Heap::AllocateUninitializedFixedArray(int length) {
   if (length == 0) return empty_fixed_array();
 
-  HeapObject* obj;
+  HeapObject* obj = nullptr;
   {
     AllocationResult allocation = AllocateRawFixedArray(length, NOT_TENURED);
     if (!allocation.To(&obj)) return allocation;
   }
 
   obj->set_map_no_write_barrier(fixed_array_map());
   FixedArray::cast(obj)->set_length(length);
   return obj;
 }
 
 
 AllocationResult Heap::AllocateUninitializedFixedDoubleArray(
     int length, PretenureFlag pretenure) {
   if (length == 0) return empty_fixed_array();
 
-  HeapObject* elements;
+  HeapObject* elements = nullptr;
   AllocationResult allocation = AllocateRawFixedDoubleArray(length, pretenure);
   if (!allocation.To(&elements)) return allocation;
 
   elements->set_map_no_write_barrier(fixed_double_array_map());
   FixedDoubleArray::cast(elements)->set_length(length);
   return elements;
 }
 
 
 AllocationResult Heap::AllocateRawFixedDoubleArray(int length,
                                                    PretenureFlag pretenure) {
   if (length < 0 || length > FixedDoubleArray::kMaxLength) {
     v8::internal::Heap::FatalProcessOutOfMemory("invalid array length",
                                                 kDoubleAligned);
   }
   int size = FixedDoubleArray::SizeFor(length);
   AllocationSpace space = SelectSpace(size, pretenure);
 
-  HeapObject* object;
+  HeapObject* object = nullptr;
   {
     AllocationResult allocation =
         AllocateRaw(size, space, OLD_SPACE, kDoubleAligned);
     if (!allocation.To(&object)) return allocation;
   }
 
   return object;
 }
 
 
 AllocationResult Heap::AllocateSymbol() {
   // Statically ensure that it is safe to allocate symbols in paged spaces.
   STATIC_ASSERT(Symbol::kSize <= Page::kMaxRegularHeapObjectSize);
 
-  HeapObject* result = NULL;
+  HeapObject* result = nullptr;
   AllocationResult allocation =
       AllocateRaw(Symbol::kSize, OLD_SPACE, OLD_SPACE);
   if (!allocation.To(&result)) return allocation;
 
   result->set_map_no_write_barrier(symbol_map());
 
   // Generate a random hash value.
   int hash;
   int attempts = 0;
   do {
@@ skipping 20 matching lines @@
     map = name##_map();             \
     break;
     STRUCT_LIST(MAKE_CASE)
 #undef MAKE_CASE
     default:
       UNREACHABLE();
       return exception();
   }
   int size = map->instance_size();
   AllocationSpace space = SelectSpace(size, TENURED);
-  Struct* result;
+  Struct* result = nullptr;
   {
     AllocationResult allocation = Allocate(map, space);
     if (!allocation.To(&result)) return allocation;
   }
   result->InitializeBody(size);
   return result;
 }
 
 
 bool Heap::IsHeapIterable() {
@@ skipping 2163 matching lines @@
     *object_sub_type = "CODE_AGE/" #name;                              \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8