Object.observe support for Function 'prototype' property

src/objects.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
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "v8.h"
 
+#include "accessors.h"
 #include "api.h"
 #include "arguments.h"
 #include "bootstrapper.h"
 #include "codegen.h"
 #include "debug.h"
 #include "deoptimizer.h"
 #include "date.h"
 #include "elements.h"
 #include "execution.h"
 #include "full-codegen.h"
@@ skipping 3060 matching lines @@
   }
 
   // From this point on everything needs to be handlified.
   HandleScope scope(isolate);
   Handle<JSObject> self(this);
   Handle<String> name(name_raw);
   Handle<Object> value(value_raw, isolate);
 
   Handle<Object> old_value(isolate->heap()->the_hole_value(), isolate);
   PropertyAttributes old_attributes = ABSENT;
-  if (FLAG_harmony_observation && map()->is_observed()) {
-    old_value = handle(lookup.GetLazyValue(), isolate);
+  bool is_observed = FLAG_harmony_observation && self->map()->is_observed();
+  if (is_observed) {
+    // Function prototypes are stored specially
+    if (self->IsJSFunction() &&
+        JSFunction::cast(*self)->should_have_prototype() &&
+        name->Equals(isolate->heap()->prototype_symbol())) {
+      MaybeObject* maybe = Accessors::FunctionGetPrototype(*self, NULL);
+      if (!maybe->ToHandle(&old_value, isolate)) return maybe;
+    } else {
+      old_value = handle(lookup.GetLazyValue(), isolate);
+    }
     old_attributes = lookup.GetAttributes();
   }
 
   // Check of IsReadOnly removed from here in clone.
   MaybeObject* result = *value;
   switch (lookup.type()) {
     case NORMAL: {
       PropertyDetails details = PropertyDetails(attributes, NORMAL);
       result = self->SetNormalizedProperty(*name, *value, details);
       break;
@@ skipping 43 matching lines @@
       break;
     }
     case HANDLER:
     case NONEXISTENT:
       UNREACHABLE();
   }
 
   Handle<Object> hresult;
   if (!result->ToHandle(&hresult, isolate)) return result;
 
-  if (FLAG_harmony_observation && map()->is_observed()) {
+  if (is_observed) {
     if (lookup.IsTransition()) {
       EnqueueChangeRecord(self, "new", name, old_value);
     } else {
       LookupResult new_lookup(isolate);
       self->LocalLookup(*name, &new_lookup, true);
       ASSERT(!new_lookup.GetLazyValue()->IsTheHole());
       if (old_value->IsTheHole() ||
           new_lookup.GetAttributes() != old_attributes) {
         EnqueueChangeRecord(self, "reconfigured", name, old_value);
       } else if (!new_lookup.GetLazyValue()->SameValue(*old_value)) {
@@ skipping 10845 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal