[runtime] Unify and fix the strict equality comparison.

src/api.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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 3387 matching lines @@
   if (self->IsJSObject() && other->IsJSObject()) {
     return *self == *other;
   }
   auto heap_object = self->IsSmi() ? other : self;
   auto context = ContextFromHeapObject(heap_object);
   return Equals(context, that).FromMaybe(false);
 }
 
 
 bool Value::StrictEquals(Local<Value> that) const {
-  i::Handle<i::Object> obj = Utils::OpenHandle(this);
-  i::Handle<i::Object> other = Utils::OpenHandle(*that);
-  if (obj->IsSmi()) {
-    return other->IsNumber() && obj->Number() == other->Number();
-  }
-  i::Isolate* isolate = i::HeapObject::cast(*obj)->GetIsolate();
-  LOG_API(isolate, "StrictEquals");
-  // Must check HeapNumber first, since NaN !== NaN.
-  if (obj->IsHeapNumber()) {
-    if (!other->IsNumber()) return false;
-    double x = obj->Number();
-    double y = other->Number();
-    // Must check explicitly for NaN:s on Windows, but -0 works fine.
-    return x == y && !std::isnan(x) && !std::isnan(y);
-  } else if (*obj == *other) {  // Also covers Booleans.
-    return true;
-  } else if (obj->IsSmi()) {
-    return other->IsNumber() && obj->Number() == other->Number();
-  } else if (obj->IsString()) {
-    return other->IsString() &&
-        i::String::Equals(i::Handle<i::String>::cast(obj),
-                          i::Handle<i::String>::cast(other));
-  } else if (obj->IsUndefined() || obj->IsUndetectableObject()) {
-    return other->IsUndefined() || other->IsUndetectableObject();

[Yang, 2015/08/17 07:13:32]

This undetectable check is lost. I guess this is intentional?

[Benedikt Meurer, 2015/08/17 07:59:49]

Yes. The code stub has an explicit comment that strict equality doesn't care
about undetectable (otherwise it wouldn't be strict). So the API implementation
was wrong.

-  } else {
-    return false;
-  }
+  auto self = Utils::OpenHandle(this);
+  auto other = Utils::OpenHandle(*that);
+  return self->StrictEquals(*other);
 }
 
 
 bool Value::SameValue(Local<Value> that) const {
   auto self = Utils::OpenHandle(this);
   auto other = Utils::OpenHandle(*that);
   return self->SameValue(*other);
 }
 
 
@@ skipping 4993 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8