Allow externalizing strings in old pointer space.

src/api.cc

 // Copyright 2012 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 5408 matching lines @@
 }
 
 
 static i::Handle<i::String> NewExternalAsciiStringHandle(
     i::Isolate* isolate,
     v8::String::ExternalAsciiStringResource* resource) {
   return isolate->factory()->NewExternalStringFromAscii(resource);
 }
 
 
-static bool RedirectToExternalString(i::Isolate* isolate,
-                                     i::Handle<i::String> parent,
-                                     i::Handle<i::String> external) {
-  if (parent->IsConsString()) {
-    i::Handle<i::ConsString> cons = i::Handle<i::ConsString>::cast(parent);
-    cons->set_first(*external);
-    cons->set_second(isolate->heap()->empty_string());
-  } else {
-    ASSERT(parent->IsSlicedString());
-    i::Handle<i::SlicedString> slice = i::Handle<i::SlicedString>::cast(parent);
-    slice->set_parent(*external);
-    slice->set_offset(0);
-  }
-  return true;
-}
-
-
 Local<String> v8::String::NewExternal(
     Isolate* isolate,
     v8::String::ExternalStringResource* resource) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   EnsureInitializedForIsolate(i_isolate, "v8::String::NewExternal()");
   LOG_API(i_isolate, "String::NewExternal");
   ENTER_V8(i_isolate);
   CHECK(resource && resource->data());
   i::Handle<i::String> result = NewExternalStringHandle(i_isolate, resource);
   i_isolate->heap()->external_string_table()->AddString(*result);
   return Utils::ToLocal(result);
 }
 
 
 bool v8::String::MakeExternal(v8::String::ExternalStringResource* resource) {
   i::Handle<i::String> obj = Utils::OpenHandle(this);
   i::Isolate* isolate = obj->GetIsolate();
   if (i::StringShape(*obj).IsExternalTwoByte()) {
     return false;  // Already an external string.
   }
   ENTER_V8(isolate);
   if (isolate->string_tracker()->IsFreshUnusedString(obj)) {
     return false;
   }
   if (isolate->heap()->IsInGCPostProcessing()) {
     return false;
   }
   CHECK(resource && resource->data());
 
-  bool result;
-  i::Handle<i::String> external;
-  if (isolate->heap()->old_pointer_space()->Contains(*obj)) {
-    // We do not allow external strings in the old pointer space.  Instead of
-    // converting the string in-place, we keep the cons/sliced string and
-    // point it to a newly-allocated external string.
-    external = NewExternalStringHandle(isolate, resource);
-    result = RedirectToExternalString(isolate, obj, external);
-  } else {
-    result = obj->MakeExternal(resource);
-    external = obj;
-  }
-
+  bool result = obj->MakeExternal(resource);
   if (result) {
-    ASSERT(external->IsExternalString());
-    isolate->heap()->external_string_table()->AddString(*external);
+    ASSERT(obj->IsExternalString());
+    isolate->heap()->external_string_table()->AddString(*obj);
   }
   return result;
 }
 
 
 Local<String> v8::String::NewExternal(
     Isolate* isolate,
     v8::String::ExternalAsciiStringResource* resource) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   EnsureInitializedForIsolate(i_isolate, "v8::String::NewExternal()");
@@ skipping 16 matching lines @@
   }
   ENTER_V8(isolate);
   if (isolate->string_tracker()->IsFreshUnusedString(obj)) {
     return false;
   }
   if (isolate->heap()->IsInGCPostProcessing()) {
     return false;
   }
   CHECK(resource && resource->data());
 
-  bool result;
-  i::Handle<i::String> external;
-  if (isolate->heap()->old_pointer_space()->Contains(*obj)) {
-    // We do not allow external strings in the old pointer space.  Instead of
-    // converting the string in-place, we keep the cons/sliced string and
-    // point it to a newly-allocated external string.
-    external = NewExternalAsciiStringHandle(isolate, resource);
-    result = RedirectToExternalString(isolate, obj, external);
-  } else {
-    result = obj->MakeExternal(resource);
-    external = obj;
-  }
-
+  bool result = obj->MakeExternal(resource);
   if (result) {
-    ASSERT(external->IsExternalString());
-    isolate->heap()->external_string_table()->AddString(*external);
+    ASSERT(obj->IsExternalString());
+    isolate->heap()->external_string_table()->AddString(*obj);
   }
   return result;
 }
 
 
 bool v8::String::CanMakeExternal() {
   if (!internal::FLAG_clever_optimizations) return false;
   i::Handle<i::String> obj = Utils::OpenHandle(this);
   i::Isolate* isolate = obj->GetIsolate();
 
@@ skipping 1839 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal