Restructure/fix thread pointer visiting; added some asserts.

runtime/vm/thread.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/thread.h"
 
 #include "vm/dart_api_state.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
@@ skipping 341 matching lines @@
 
 
 void Thread::ClearReusableHandles() {
 #define CLEAR_REUSABLE_HANDLE(object)                                          \
   *object##_handle_ = object::null();
   REUSABLE_HANDLE_LIST(CLEAR_REUSABLE_HANDLE)
 #undef CLEAR_REUSABLE_HANDLE
 }
 
 
-void Thread::VisitObjectPointers(ObjectPointerVisitor* visitor) {
+void Thread::VisitObjectPointers(ObjectPointerVisitor* visitor,
+                                 bool validate_frames) {
   ASSERT(visitor != NULL);
 
+  if (zone_ != NULL) {
+    zone_->VisitObjectPointers(visitor);
+  }
+
   // Visit objects in thread specific handles area.
   reusable_handles_.VisitObjectPointers(visitor);
 
   visitor->VisitPointer(
       reinterpret_cast<RawObject**>(&pending_functions_));
   visitor->VisitPointer(
       reinterpret_cast<RawObject**>(&sticky_error_));
 
   // Visit the api local scope as it has all the api local handles.
   ApiLocalScope* scope = api_top_scope_;
   while (scope != NULL) {
     scope->local_handles()->VisitObjectPointers(visitor);
     scope = scope->previous();
   }
+
+  // Iterate over all the stack frames and visit objects on the stack.
+  StackFrameIterator frames_iterator(top_exit_frame_info(),
+                                     validate_frames);
+  StackFrame* frame = frames_iterator.NextFrame();
+  while (frame != NULL) {
+    frame->VisitObjectPointers(visitor);
+    frame = frames_iterator.NextFrame();
+  }
 }
 
 
 bool Thread::CanLoadFromThread(const Object& object) {
 #define CHECK_OBJECT(type_name, member_name, expr, default_init_value)         \
   if (object.raw() == expr) return true;
 CACHED_VM_OBJECTS_LIST(CHECK_OBJECT)
 #undef CHECK_OBJECT
   return false;
 }
@@ skipping 117 matching lines @@
 
 DisableThreadInterruptsScope::~DisableThreadInterruptsScope() {
   if (thread() != NULL) {
     OSThread* os_thread = thread()->os_thread();
     ASSERT(os_thread != NULL);
     os_thread->EnableThreadInterrupts();
   }
 }
 
 }  // namespace dart