Phantom references support internal fields

src/debug.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/v8.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 677 matching lines @@
       reinterpret_cast<ScriptCache*>(data.GetParameter());
   HashMap::Entry* entry = script_cache->Lookup(key, hash, false);
   Object** location = reinterpret_cast<Object**>(entry->value);
   script_cache->Remove(key, hash);
 
   // Clear the weak handle.
   GlobalHandles::Destroy(location);
 }
 
 
-void Debug::HandleWeakDebugInfo(
-    const v8::WeakCallbackData<v8::Value, void>& data) {
+void Debug::HandlePhantomDebugInfo(
+    const v8::PhantomCallbackData<DebugInfoListNode>& data) {
   Debug* debug = reinterpret_cast<Isolate*>(data.GetIsolate())->debug();
-  DebugInfoListNode* node =
-      reinterpret_cast<DebugInfoListNode*>(data.GetParameter());
-  debug->RemoveDebugInfo(node->debug_info().location());
+  DebugInfoListNode* node = data.GetParameter();
+  debug->RemoveDebugInfo(node);
 #ifdef DEBUG
   for (DebugInfoListNode* n = debug->debug_info_list_;
        n != NULL;
        n = n->next()) {
     DCHECK(n != node);
   }
 #endif
 }
 
 
 DebugInfoListNode::DebugInfoListNode(DebugInfo* debug_info): next_(NULL) {
   // Globalize the request debug info object and make it weak.
   GlobalHandles* global_handles = debug_info->GetIsolate()->global_handles();
   debug_info_ = Handle<DebugInfo>::cast(global_handles->Create(debug_info));
-  GlobalHandles::MakeWeak(reinterpret_cast<Object**>(debug_info_.location()),
-                          this, Debug::HandleWeakDebugInfo,
-                          GlobalHandles::Phantom);
+  typedef PhantomCallbackData<void>::Callback Callback;
+  GlobalHandles::MakePhantom(
+      reinterpret_cast<Object**>(debug_info_.location()), this,
+      reinterpret_cast<Callback>(Debug::HandlePhantomDebugInfo));
 }
 
 
 DebugInfoListNode::~DebugInfoListNode() {
   GlobalHandles::Destroy(reinterpret_cast<Object**>(debug_info_.location()));
 }
 
 
 bool Debug::CompileDebuggerScript(Isolate* isolate, int index) {
   Factory* factory = isolate->factory();
@@ skipping 1502 matching lines @@
 
   // Add debug info to the list.
   DebugInfoListNode* node = new DebugInfoListNode(*debug_info);
   node->set_next(debug_info_list_);
   debug_info_list_ = node;
 
   return true;
 }
 
 
-// This uses the location of a handle to look up the debug info in the debug
-// info list, but it doesn't use the actual debug info for anything.  Therefore
-// if the debug info has been collected by the GC, we can be sure that this
-// method will not attempt to resurrect it.
+void Debug::RemoveDebugInfo(DebugInfoListNode* prev, DebugInfoListNode* node) {
+  // Unlink from list. If prev is NULL we are looking at the first element.
+  if (prev == NULL) {
+    debug_info_list_ = node->next();
+  } else {
+    prev->set_next(node->next());
+  }
+  delete node;
+
+  // If there are no more debug info objects there are not more break
+  // points.
+  has_break_points_ = debug_info_list_ != NULL;
+}
+
+
 void Debug::RemoveDebugInfo(DebugInfo** debug_info) {
   DCHECK(debug_info_list_ != NULL);
   // Run through the debug info objects to find this one and remove it.
   DebugInfoListNode* prev = NULL;
   DebugInfoListNode* current = debug_info_list_;
   while (current != NULL) {
     if (current->debug_info().location() == debug_info) {
-      // Unlink from list. If prev is NULL we are looking at the first element.
-      if (prev == NULL) {
-        debug_info_list_ = current->next();
-      } else {
-        prev->set_next(current->next());
-      }
-      delete current;
-
-      // If there are no more debug info objects there are not more break
-      // points.
-      has_break_points_ = debug_info_list_ != NULL;
-
+      RemoveDebugInfo(prev, current);
       return;
     }
     // Move to next in list.
+    prev = current;
+    current = current->next();
+  }
+  UNREACHABLE();
+}
+
+
+void Debug::RemoveDebugInfo(DebugInfoListNode* node) {
+  DCHECK(debug_info_list_ != NULL);
+  // Run through the debug info objects to find this one and remove it.
+  DebugInfoListNode* prev = NULL;
+  DebugInfoListNode* current = debug_info_list_;
+  while (current != NULL) {
+    if (current == node) {
+      RemoveDebugInfo(prev, node);
+      return;
+    }
+    // Move to next in list.
     prev = current;
     current = current->next();
   }
   UNREACHABLE();
 }
 
 
 void Debug::RemoveDebugInfoAndClearFromShared(Handle<DebugInfo> debug_info) {
   HandleScope scope(isolate_);
   Handle<SharedFunctionInfo> shared(debug_info->shared());
@@ skipping 1195 matching lines @@
   logger_->DebugEvent("Put", message.text());
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 } }  // namespace v8::internal