Revert of Serializer: clear string hash for code serializer.

src/snapshot/serialize.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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
@@ skipping 696 matching lines @@
     return handle(string_, isolate);
   }
 
   String* string_;
   uint32_t hash_;
 };
 
 
 HeapObject* Deserializer::PostProcessNewObject(HeapObject* obj, int space) {
   if (deserializing_user_code()) {
-    if (obj->IsInternalizedString()) {
-      // Canonicalize the internalized string. If it already exists in the
-      // string table, set it to forward to the existing one.
-      DisallowHeapAllocation no_gc;
+    if (obj->IsString()) {
       String* string = String::cast(obj);
-      HandleScope scope(isolate_);
-      StringTableInsertionKey key(string);
-      String* canonical = *StringTable::LookupKey(isolate_, &key);
-      string->SetForwardedInternalizedString(canonical);
-      return canonical;
+      // Uninitialize hash field as the hash seed may have changed.
+      string->set_hash_field(String::kEmptyHashField);
+      if (string->IsInternalizedString()) {
+        // Canonicalize the internalized string. If it already exists in the
+        // string table, set it to forward to the existing one.
+        DisallowHeapAllocation no_gc;
+        HandleScope scope(isolate_);
+        StringTableInsertionKey key(string);
+        String* canonical = *StringTable::LookupKey(isolate_, &key);
+        string->SetForwardedInternalizedString(canonical);
+        return canonical;
+      }
     } else if (obj->IsScript()) {
       // Assign a new script id to avoid collision.
       Script::cast(obj)->set_id(isolate_->heap()->NextScriptId());
     } else {
       DCHECK(CanBeDeferred(obj));
     }
   }
   if (obj->IsAllocationSite()) {
     DCHECK(obj->IsAllocationSite());
     // Allocation sites are present in the snapshot, and must be linked into
@@ skipping 1556 matching lines @@
   // We expect no instantiated function objects or contexts.
   CHECK(!obj->IsJSFunction() && !obj->IsContext());
 
   SerializeGeneric(obj, how_to_code, where_to_point);
 }
 
 
 void CodeSerializer::SerializeGeneric(HeapObject* heap_object,
                                       HowToCode how_to_code,
                                       WhereToPoint where_to_point) {
-  int string_hash = String::kEmptyHashField;
-  if (heap_object->IsString()) {
-    String* string = String::cast(heap_object);
-    if (string->IsInternalizedString()) num_internalized_strings_++;
-    // Temporarily clear string hash.
-    string_hash = string->hash_field();
-    string->set_hash_field(String::kEmptyHashField);
-  }
+  if (heap_object->IsInternalizedString()) num_internalized_strings_++;
 
   // Object has not yet been serialized.  Serialize it here.
   ObjectSerializer serializer(this, heap_object, sink_, how_to_code,
                               where_to_point);
   serializer.Serialize();
-
-  if (string_hash != String::kEmptyHashField) {
-    // Restore string hash.
-    String::cast(heap_object)->set_hash_field(String::kEmptyHashField);
-  }
 }
 
 
 void CodeSerializer::SerializeBuiltin(int builtin_index, HowToCode how_to_code,
                                       WhereToPoint where_to_point) {
   DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) ||
          (how_to_code == kPlain && where_to_point == kInnerPointer) ||
          (how_to_code == kFromCode && where_to_point == kInnerPointer));
   DCHECK_LT(builtin_index, Builtins::builtin_count);
   DCHECK_LE(0, builtin_index);
@@ skipping 367 matching lines @@
   SerializedCodeData* scd = new SerializedCodeData(cached_data);
   SanityCheckResult r = scd->SanityCheck(isolate, source);
   if (r == CHECK_SUCCESS) return scd;
   cached_data->Reject();
   source->GetIsolate()->counters()->code_cache_reject_reason()->AddSample(r);
   delete scd;
   return NULL;
 }
 }  // namespace internal
 }  // namespace v8