Serialize external strings in the code serializer.

test/cctest/test-serialize.cc

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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
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@@ skipping 883 matching lines @@
       Execution::Call(isolate, copy_fun, global, 0, NULL).ToHandleChecked();
 
   CHECK_EQ(6 * 1000000, Handle<String>::cast(copy_result)->length());
   CHECK(isolate->heap()->InSpace(HeapObject::cast(*copy_result), LO_SPACE));
 
   delete cache;
   source.Dispose();
 }
 
 
+class OneByteResource : public v8::String::ExternalOneByteStringResource {
+ public:
+  OneByteResource(const char* data, size_t length)
+      : data_(data), length_(length) {}
+  virtual const char* data() const { return data_; }
+  virtual size_t length() const { return length_; }
+
+ private:
+  const char* data_;
+  size_t length_;
+};
+
+
+class TwoByteResource : public v8::String::ExternalStringResource {
+ public:
+  TwoByteResource(const char* data, size_t length)
+      : data_(AsciiToTwoByteString(data)), length_(length) {}
+  ~TwoByteResource() { DeleteArray<const uint16_t>(data_); }
+
+  virtual const uint16_t* data() const { return data_; }
+  virtual size_t length() const { return length_; }
+
+ private:
+  const uint16_t* data_;
+  size_t length_;
+};
+
+
+TEST(SerializeToplevelExternalString) {
+  FLAG_serialize_toplevel = true;
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  isolate->compilation_cache()->Disable();  // Disable same-isolate code cache.
+
+  v8::HandleScope scope(CcTest::isolate());
+
+  // Obtain external internalized one-byte string.
+  OneByteResource one_byte_resource("one_byte", 8);
+  Handle<String> one_byte_string =
+      isolate->factory()->NewStringFromAsciiChecked("one_byte");
+  one_byte_string = isolate->factory()->InternalizeString(one_byte_string);
+  one_byte_string->MakeExternal(&one_byte_resource);
+  CHECK(one_byte_string->IsExternalOneByteString());
+  CHECK(one_byte_string->IsInternalizedString());
+
+  // Obtain external internalized two-byte string.
+  TwoByteResource two_byte_resource("two_byte", 8);
+  Handle<String> two_byte_string =
+      isolate->factory()->NewStringFromAsciiChecked("two_byte");
+  two_byte_string = isolate->factory()->InternalizeString(two_byte_string);
+  two_byte_string->MakeExternal(&two_byte_resource);

[mvstanton, 2014/10/01 14:26:21]

I like these tests. Nit: Is it possible to check that the external string for
"one_byte" and "two_byte" do not exist in the context that you deserialize into?
That would verify that you don't create an external string, but just an
internalized string. I guess you'd have to make a new handle scope for that?

+  CHECK(two_byte_string->IsExternalTwoByteString());
+  CHECK(two_byte_string->IsInternalizedString());
+
+  const char* source =
+      "var o = {}               \n"
+      "o.one_byte = 7;          \n"
+      "o.two_byte = 8;          \n"
+      "o.one_byte + o.two_byte; \n";
+  Handle<String> source_string = isolate->factory()
+                                     ->NewStringFromUtf8(CStrVector(source))
+                                     .ToHandleChecked();
+
+  Handle<JSObject> global(isolate->context()->global_object());
+  ScriptData* cache = NULL;
+
+  Handle<SharedFunctionInfo> orig = Compiler::CompileScript(
+      source_string, Handle<String>(), 0, 0, false,
+      Handle<Context>(isolate->native_context()), NULL, &cache,
+      v8::ScriptCompiler::kProduceCodeCache, NOT_NATIVES_CODE);
+
+  Handle<SharedFunctionInfo> copy;
+  {
+    DisallowCompilation no_compile_expected(isolate);
+    copy = Compiler::CompileScript(
+        source_string, Handle<String>(), 0, 0, false,
+        Handle<Context>(isolate->native_context()), NULL, &cache,
+        v8::ScriptCompiler::kConsumeCodeCache, NOT_NATIVES_CODE);
+  }
+  CHECK_NE(*orig, *copy);
+
+  Handle<JSFunction> copy_fun =
+      isolate->factory()->NewFunctionFromSharedFunctionInfo(
+          copy, isolate->native_context());
+
+  Handle<Object> copy_result =
+      Execution::Call(isolate, copy_fun, global, 0, NULL).ToHandleChecked();
+
+  CHECK_EQ(15.0f, copy_result->Number());
+
+  delete cache;
+}
+
+
+TEST(SerializeToplevelLargeExternalString) {
+  FLAG_serialize_toplevel = true;
+  LocalContext context;
+  Isolate* isolate = CcTest::i_isolate();
+  isolate->compilation_cache()->Disable();  // Disable same-isolate code cache.
+
+  Factory* f = isolate->factory();
+
+  v8::HandleScope scope(CcTest::isolate());
+
+  // Create a huge external internalized string to use as variable name.
+  Vector<const uint8_t> string =
+      ConstructSource(STATIC_CHAR_VECTOR(""), STATIC_CHAR_VECTOR("abcdef"),
+                      STATIC_CHAR_VECTOR(""), 1000000);
+  Handle<String> name = f->NewStringFromOneByte(string).ToHandleChecked();
+  OneByteResource one_byte_resource(
+      reinterpret_cast<const char*>(string.start()), string.length());
+  name = f->InternalizeString(name);
+  name->MakeExternal(&one_byte_resource);
+  CHECK(name->IsExternalOneByteString());
+  CHECK(name->IsInternalizedString());
+  CHECK(isolate->heap()->InSpace(*name, LO_SPACE));
+
+  // Create the source, which is "var <literal> = 42; <literal>".
+  Handle<String> source_str =
+      f->NewConsString(
+             f->NewConsString(f->NewStringFromAsciiChecked("var "), name)
+                 .ToHandleChecked(),
+             f->NewConsString(f->NewStringFromAsciiChecked(" = 42; "), name)
+                 .ToHandleChecked()).ToHandleChecked();
+
+  Handle<JSObject> global(isolate->context()->global_object());
+  ScriptData* cache = NULL;
+
+  Handle<SharedFunctionInfo> orig = Compiler::CompileScript(
+      source_str, Handle<String>(), 0, 0, false,
+      Handle<Context>(isolate->native_context()), NULL, &cache,
+      v8::ScriptCompiler::kProduceCodeCache, NOT_NATIVES_CODE);
+
+  Handle<SharedFunctionInfo> copy;
+  {
+    DisallowCompilation no_compile_expected(isolate);
+    copy = Compiler::CompileScript(
+        source_str, Handle<String>(), 0, 0, false,
+        Handle<Context>(isolate->native_context()), NULL, &cache,
+        v8::ScriptCompiler::kConsumeCodeCache, NOT_NATIVES_CODE);
+  }
+  CHECK_NE(*orig, *copy);
+
+  Handle<JSFunction> copy_fun =
+      isolate->factory()->NewFunctionFromSharedFunctionInfo(
+          copy, isolate->native_context());
+
+  Handle<Object> copy_result =
+      Execution::Call(isolate, copy_fun, global, 0, NULL).ToHandleChecked();
+
+  CHECK_EQ(42.0f, copy_result->Number());
+
+  delete cache;
+  string.Dispose();
+}
+
+
 TEST(SerializeToplevelIsolates) {
   FLAG_serialize_toplevel = true;
 
   const char* source = "function f() { return 'abc'; }; f() + 'def'";
   v8::ScriptCompiler::CachedData* cache;
 
   v8::Isolate* isolate1 = v8::Isolate::New();
   {
     v8::Isolate::Scope iscope(isolate1);
     v8::HandleScope scope(isolate1);
@@ skipping 31 matching lines @@
     {
       DisallowCompilation no_compile(reinterpret_cast<Isolate*>(isolate2));
       script = v8::ScriptCompiler::CompileUnbound(
           isolate2, &source, v8::ScriptCompiler::kConsumeCodeCache);
     }
     v8::Local<v8::Value> result = script->BindToCurrentContext()->Run();
     CHECK(result->ToString()->Equals(v8_str("abcdef")));
   }
   isolate2->Dispose();
 }