[strong] Implement strong mode restrictions on property access

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index fe1a4336eea973a777f270b17cc292a9aad65821..86fcb9ae2410d064e3e8f258925aee005b9efa95 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -127,7 +127,7 @@ bool Object::IsPromise(Handle<Object> object) {
 }
 
 
-MaybeHandle<Object> Object::GetProperty(LookupIterator* it) {
+MaybeHandle<Object> Object::GetProperty(LookupIterator* it, Strength strength) {

[Toon Verwaest, 2015/06/09 11:58:04]

It would be nicer if GetProperty etc would also get a LanguageMode. Both
DeleteProperty and SetProperty already get that. And if we do that, we could
encapsulate it in the LookupIterator. I see how this is a bit annoying since you
are saving bits though ... not sure.

[conradw, 2015/06/09 13:09:27]

Yeah, this is kind of annoying. Putting more than a bit in the minor key means
that sloppy and strict versions of the stub would get cached separately though,
so it's hard to have these functions taking LanguageMode instead of Strength
without either lying or causing a regression.

[Toon Verwaest, 2015/06/09 13:38:43]

Since type feedback vectors, aren't there only 2 stubs per language mode? That
seems manageable...

   for (; it->IsFound(); it->Next()) {
     switch (it->state()) {
       case LookupIterator::NOT_FOUND:
@@ -145,15 +145,27 @@ MaybeHandle<Object> Object::GetProperty(LookupIterator* it) {
       }
       case LookupIterator::ACCESS_CHECK:
         if (it->HasAccess()) break;
-        return JSObject::GetPropertyWithFailedAccessCheck(it);
+        return JSObject::GetPropertyWithFailedAccessCheck(it, strength);
       case LookupIterator::ACCESSOR:
-        return GetPropertyWithAccessor(it);
+        return GetPropertyWithAccessor(it, strength);
       case LookupIterator::INTEGER_INDEXED_EXOTIC:
+        if (is_strong(strength)) {

[Toon Verwaest, 2015/06/09 11:58:04]

What about extracting this in a helper method. See WriteToReadOnlyProperty for
an example.

[conradw, 2015/06/09 13:09:27]

Done.

+          THROW_NEW_ERROR(it->isolate(),
+                          NewTypeError(MessageTemplate::kStrongPropertyAccess,
+                                       it->GetReceiver(), it->GetName()),
+                          Object);
+        }
         return it->factory()->undefined_value();
       case LookupIterator::DATA:
         return it->GetDataValue();
     }
   }
+  if (is_strong(strength)) {
+    THROW_NEW_ERROR(it->isolate(),
+                    NewTypeError(MessageTemplate::kStrongPropertyAccess,
+                                 it->GetReceiver(), it->GetName()),
+                    Object);
+  }
   return it->factory()->undefined_value();
 }
 
@@ -302,7 +314,8 @@ MaybeHandle<Object> JSProxy::GetPropertyWithHandler(Handle<JSProxy> proxy,
 }
 
 
-MaybeHandle<Object> Object::GetPropertyWithAccessor(LookupIterator* it) {
+MaybeHandle<Object> Object::GetPropertyWithAccessor(LookupIterator* it,
+                                                    Strength strength) {
   Isolate* isolate = it->isolate();
   Handle<Object> structure = it->GetAccessors();
   Handle<Object> receiver = it->GetReceiver();
@@ -332,6 +345,12 @@ MaybeHandle<Object> Object::GetPropertyWithAccessor(LookupIterator* it) {
         args.Call(call_fun, v8::Utils::ToLocal(name));
     RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
     if (result.IsEmpty()) {
+      if (is_strong(strength)) {
+        THROW_NEW_ERROR(isolate,
+                        NewTypeError(MessageTemplate::kStrongPropertyAccess,
+                                     receiver, name),
+                        Object);
+      }
       return isolate->factory()->undefined_value();
     }
     Handle<Object> return_value = v8::Utils::OpenHandle(*result);
@@ -349,6 +368,12 @@ MaybeHandle<Object> Object::GetPropertyWithAccessor(LookupIterator* it) {
         receiver, Handle<JSReceiver>::cast(getter));
   }
   // Getter is not a function.
+  if (is_strong(strength)) {
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kStrongPropertyAccess,
+                                 receiver, it->GetName()),
+                    Object);
+  }
   return isolate->factory()->undefined_value();
 }
 
@@ -487,11 +512,11 @@ static bool FindAllCanReadHolder(LookupIterator* it) {
 
 
 MaybeHandle<Object> JSObject::GetPropertyWithFailedAccessCheck(
-    LookupIterator* it) {
+    LookupIterator* it, Strength strength) {
   Handle<JSObject> checked = it->GetHolder<JSObject>();
   while (FindAllCanReadHolder(it)) {
     if (it->state() == LookupIterator::ACCESSOR) {
-      return GetPropertyWithAccessor(it);
+      return GetPropertyWithAccessor(it, strength);
     }
     DCHECK_EQ(LookupIterator::INTERCEPTOR, it->state());
     auto result = GetPropertyWithInterceptor(it);