Fix stub frame walking: when materializing the frame content during deoptimization, the stack is no…

runtime/vm/object.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 4307 matching lines @@
  private:
   static void UnpackInto(const Array& table,
                          const TypedData& packed,
                          GrowableArray<DeoptInstr*>* instructions,
                          intptr_t length);
 };
 
 
 class Code : public Object {
  public:
-  uword active_entry_point() const { return raw_ptr()->entry_point_; }
+  RawInstructions* active_instructions() const {
+    return raw_ptr()->active_instructions_;
+  }
 
   RawInstructions* instructions() const { return raw_ptr()->instructions_; }
 
   static intptr_t saved_instructions_offset() {
     return OFFSET_OF(RawCode, instructions_);
   }
 
   static intptr_t entry_point_offset() {
     return OFFSET_OF(RawCode, entry_point_);
   }
@@ skipping 261 matching lines @@
   bool IsStubCode() const;
   bool IsFunctionCode() const;
 
   void DisableDartCode() const;
 
   void DisableStubCode() const;
 
   void Enable() const {
     if (!IsDisabled()) return;
     ASSERT(Thread::Current()->IsMutatorThread());
+    ASSERT(instructions() != active_instructions());
     SetActiveInstructions(instructions());
   }
 
   bool IsDisabled() const {
-    return active_entry_point() != EntryPoint();
+    return instructions() != active_instructions();
   }
 
  private:
   void set_state_bits(intptr_t bits) const;
 
   void set_object_pool(RawObjectPool* object_pool) const {
     StorePointer(&raw_ptr()->object_pool_, object_pool);
   }
 
   friend class RawObject;  // For RawObject::SizeFromClass().
@@ skipping 3792 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_