Update ObjectToString to Harmony-draft algorithm

test/cctest/test-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 2003 matching lines @@
 
 void SymbolAccessorSetter(Local<Name> name, Local<Value> value,
                           const v8::PropertyCallbackInfo<void>& info) {
   CHECK(name->IsSymbol());
   Local<Symbol> sym = Local<Symbol>::Cast(name);
   if (sym->Name()->IsUndefined())
     return;
   SimpleAccessorSetter(Local<String>::Cast(sym->Name()), value, info);
 }
 
+void SymbolAccessorGetterReturnsDefault(Local<Name> name,
+                          const v8::PropertyCallbackInfo<v8::Value>& info) {
+  CHECK(name->IsSymbol());
+  Local<Symbol> sym = Local<Symbol>::Cast(name);
+  if (sym->Name()->IsUndefined())
+    return;
+  info.GetReturnValue().Set(info.Data());
+}
+
+static void ThrowingSymbolAccessorGetter(
+    Local<Name> name,
+    const v8::PropertyCallbackInfo<v8::Value>& info) {
+  ApiTestFuzzer::Fuzz();

[Dmitry Lomov (no reviews), 2014/10/18 21:24:19]

Why this line?

+  info.GetReturnValue().Set(info.GetIsolate()->ThrowException(name));
+}
+
 void EmptyInterceptorGetter(Local<String> name,
                             const v8::PropertyCallbackInfo<v8::Value>& info) {
 }
 
 void EmptyInterceptorSetter(Local<String> name,
                             Local<Value> value,
                             const v8::PropertyCallbackInfo<v8::Value>& info) {
 }
 
 void InterceptorGetter(Local<String> name,
@@ skipping 11448 matching lines @@
   CHECK(value->IsString() && value->Equals(v8_str("[object MyClass]")));
 
   // Check global
   value = context->Global()->ObjectProtoToString();
   CHECK(value->IsString() && value->Equals(v8_str("[object global]")));
 
   // Check ordinary object
   Local<Value> object = v8_compile("new Object()")->Run();
   value = object.As<v8::Object>()->ObjectProtoToString();
   CHECK(value->IsString() && value->Equals(v8_str("[object Object]")));
+
+  // Check that ES6 semantics using @@toStringTag work
+  i::FLAG_harmony_tostring = true;
+  Local<v8::Symbol> toStringTag = v8::Symbol::GetToStringTag(isolate);
+
+#define TEST_TOSTRINGTAG(type, tag, expected) \
+  do { \
+    object = v8_compile("new " #type "()")->Run(); \

[Dmitry Lomov (no reviews), 2014/10/18 21:24:19]

Nit: use CompileRun here

+    object.As<v8::Object>()->Set(toStringTag, v8_str(#tag)); \
+    value = object.As<v8::Object>()->ObjectProtoToString(); \
+    CHECK(value->IsString() && value->Equals( \
+        v8_str("[object " #expected "]"))); \
+  } while (0)
+
+  TEST_TOSTRINGTAG(Array, Object, Object);
+  TEST_TOSTRINGTAG(Object, Arguments, ~Arguments);
+  TEST_TOSTRINGTAG(Object, Array, ~Array);
+  TEST_TOSTRINGTAG(Object, Boolean, ~Boolean);
+  TEST_TOSTRINGTAG(Object, Date, ~Date);
+  TEST_TOSTRINGTAG(Object, Error, ~Error);
+  TEST_TOSTRINGTAG(Object, Function, ~Function);
+  TEST_TOSTRINGTAG(Object, Number, ~Number);
+  TEST_TOSTRINGTAG(Object, RegExp, ~RegExp);
+  TEST_TOSTRINGTAG(Object, String, ~String);
+  TEST_TOSTRINGTAG(Object, Foo, Foo);
+
+#undef TEST_TOSTRINGTAG
+
+  // @@toStringTag getter throws
+  Local<v8::Object> obj = v8::Object::New(isolate);

[Dmitry Lomov (no reviews), 2014/10/18 21:24:19]

Great test, add one more where the getter is actually written in Javascript:

Local<v8::Value> obj = CompileRun(
          "o = {};"
          "Object.defineProperty(o, Symbol.toStringTag, { ... };"
          " o");

so that ObjectProtoToString actually executes some Javascript code.

[caitp (gmail), 2014/10/18 21:27:40]

There's a problem with that --- the bootstrapper didn't load harmony-tostring,
flipping the flag won't make it use the right function. I'm not sure if there's
a way to re-bootstrap mid-test or something.

[caitp (gmail), 2014/10/18 21:35:01]

Er, I mean `Symbol.toStringTag` is not exposed --- I could expose that easily,
but it still wouldn't use the right function --- I guess that doesn't matter for
the runtime tests though

[Dmitry Lomov (no reviews), 2014/10/18 21:45:00]

Ah, I see. Extract the tests for toStringTag into a separate test.
Use UNINITIALIZED_TEST macro for it instead of THREADED_TEST.
 Add 
    FLAG_harmony_tostring = true; 
    CcTest::InitializeVM();
at the beginning of your test.

+  obj->SetAccessor(toStringTag, ThrowingSymbolAccessorGetter);
+  { TryCatch try_catch;
+    value = obj->ObjectProtoToString();
+    CHECK(value.IsEmpty());
+    CHECK(try_catch.HasCaught());
+  }
+
+  // @@toStringTag getter does not throw
+  obj = v8::Object::New(isolate);
+  obj->SetAccessor(toStringTag, SymbolAccessorGetterReturnsDefault,
+                   0, v8_str("Test"));
+  { TryCatch try_catch;
+    value = obj->ObjectProtoToString();
+    CHECK(value->IsString() && value->Equals(v8_str("[object Test]")));
+    CHECK(!try_catch.HasCaught());
+  }
 }
 
 
 THREADED_TEST(ObjectGetConstructorName) {
   LocalContext context;
   v8::HandleScope scope(context->GetIsolate());
   v8_compile("function Parent() {};"
              "function Child() {};"
              "Child.prototype = new Parent();"
              "var outer = { inner: function() { } };"
@@ skipping 10332 matching lines @@
   char chunk2[] =
       "XXr = 13;\n"
       "  return foob\xeb\x91\x80\xeb\x91\x80r;\n"
       "}\n";
   chunk1[strlen(chunk1) - 1] = reference[0];
   chunk2[0] = reference[1];
   chunk2[1] = reference[2];
   const char* chunks[] = {chunk1, chunk2, "foo();", NULL};
   RunStreamingTest(chunks, v8::ScriptCompiler::StreamedSource::UTF8);
 }