Make Object.observe on the global object functional

src/runtime.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 13140 matching lines @@
   ASSERT(args.length() == 2);
   CONVERT_ARG_CHECKED(JSObject, obj1, 0);
   CONVERT_ARG_CHECKED(JSObject, obj2, 1);
   return isolate->heap()->ToBoolean(obj1->map() == obj2->map());
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_IsObserved) {
   ASSERT(args.length() == 1);
   CONVERT_ARG_CHECKED(JSReceiver, obj, 0);
+  if (obj->IsJSGlobalProxy()) {
+    Object* proto = obj->GetPrototype();
+    if (obj->IsNull()) return isolate->heap()->undefined_value();

[rossberg, 2012/11/21 12:43:17]

Perhaps you should return false here.

[adamk, 2012/11/21 17:02:57]

Ah, that's probably a better plan, yes.

+    ASSERT(proto->IsJSGlobalObject());
+    obj = JSReceiver::cast(proto);
+  }
   return isolate->heap()->ToBoolean(obj->map()->is_observed());
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SetIsObserved) {
   ASSERT(args.length() == 2);
   CONVERT_ARG_CHECKED(JSReceiver, obj, 0);
   CONVERT_BOOLEAN_ARG_CHECKED(is_observed, 1);
+  JSGlobalProxy* global_proxy = NULL;

[rossberg, 2012/11/21 12:43:17]

What do you need this for?

[adamk, 2012/11/21 17:02:57]

Cruft from a previous version before I discovered global_receiver(). Removed.

+  if (obj->IsJSGlobalProxy()) {
+    Object* proto = obj->GetPrototype();
+    if (obj->IsNull()) return isolate->heap()->undefined_value();
+    ASSERT(proto->IsJSGlobalObject());
+    global_proxy = JSGlobalProxy::cast(obj);
+    obj = JSReceiver::cast(proto);
+  }
   if (obj->map()->is_observed() != is_observed) {
     MaybeObject* maybe = obj->map()->Copy();
     Map* map;
     if (!maybe->To(&map)) return maybe;
     map->set_is_observed(is_observed);
     obj->set_map(map);
   }
   return isolate->heap()->undefined_value();
 }
 
@@ skipping 15 matching lines @@
   ASSERT(args.length() == 0);
   return ObjectHashTable::Allocate(0);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ObjectHashTableGet) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
   CONVERT_ARG_CHECKED(ObjectHashTable, table, 0);
   Object* key = args[1];
+  if (key->IsJSGlobalProxy()) {
+    key = key->GetPrototype();
+    if (key->IsNull()) return isolate->heap()->undefined_value();
+  }
   Object* lookup = table->Lookup(key);
   return lookup->IsTheHole() ? isolate->heap()->undefined_value() : lookup;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ObjectHashTableSet) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(ObjectHashTable, table, 0);
   Handle<Object> key = args.at<Object>(1);
+  if (key->IsJSGlobalProxy()) {
+    key = handle(key->GetPrototype(), isolate);
+    if (key->IsNull()) return isolate->heap()->undefined_value();

[rossberg, 2012/11/21 12:43:17]

Return this.

[adamk, 2012/11/21 17:02:57]

Woops, fixed. This is one that will be covered by the API test.

+  }
   Handle<Object> value = args.at<Object>(2);
   return *PutIntoObjectHashTable(table, key, value);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ObjectHashTableHas) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
   CONVERT_ARG_CHECKED(ObjectHashTable, table, 0);
   Object* key = args[1];
+  if (key->IsJSGlobalProxy()) {
+    key = key->GetPrototype();
+    if (key->IsNull()) return isolate->heap()->undefined_value();

[rossberg, 2012/11/21 12:43:17]

False here, too.

[adamk, 2012/11/21 17:02:57]

This function wasn't carrying its weight, just removed and implemented in JS.

[rossberg, 2012/11/22 12:17:05]

I'm fine with that. But note that there no longer is a way to differentiate
between an absent key and a key mapping to 'undefined'. Not that anybody should
ever need that...

+  }
   Object* lookup = table->Lookup(key);
   return isolate->heap()->ToBoolean(!lookup->IsTheHole());
 }
 
 
 // ----------------------------------------------------------------------------
 // Implementation of Runtime
 
 #define F(name, number_of_args, result_size)                             \
   { Runtime::k##name, Runtime::RUNTIME, #name,   \
@@ skipping 71 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal