Fix PcDescriptor iteratot to never return a pointer to a memory location since the data can move wi…

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 <limits>
 #include "include/dart_api.h"
 #include "platform/assert.h"
@@ skipping 3024 matching lines @@
 
   // Verify (assert) assumptions about pc descriptors in debug mode.
   void Verify(const Function& function) const;
 
   static void PrintHeaderString();
 
   void PrintToJSONObject(JSONObject* jsobj) const;
 
   // We would have a VisitPointers function here to traverse the
   // pc descriptors table to visit objects if any in the table.
-
+  // Note: never return a reference to a RawPcDescriptors::PcDescriptorRec
+  // as the object can move.
   class Iterator : ValueObject {
    public:
     Iterator(const PcDescriptors& descriptors, intptr_t kind_mask)
         : descriptors_(descriptors), kind_mask_(kind_mask), current_ix_(0) {
       MoveToMatching();
     }
 
     bool HasNext() const { return current_ix_ < descriptors_.Length(); }
 
-    const RawPcDescriptors::PcDescriptorRec& Next() {
+    intptr_t NextDeoptId() {
       ASSERT(HasNext());
-      const RawPcDescriptors::PcDescriptorRec* res =
-         descriptors_.recAt(current_ix_++);
+      const intptr_t res = descriptors_.recAt(current_ix_++)->deopt_id();
       MoveToMatching();
-      return *res;
+      return res;
+    }
+
+    uword NextPc() {
+      ASSERT(HasNext());
+      const uword res = descriptors_.recAt(current_ix_++)->pc();
+      MoveToMatching();
+      return res;
+    }
+
+    void NextRec(RawPcDescriptors::PcDescriptorRec* result) {
+      ASSERT(HasNext());
+      const RawPcDescriptors::PcDescriptorRec* r =
+          descriptors_.recAt(current_ix_++);
+      r->CopyTo(result);
+      MoveToMatching();
     }
 
    private:
     friend class PcDescriptors;
 
     // For nested iterations, starting at element after.
     explicit Iterator(const Iterator& iter)
         : ValueObject(),
           descriptors_(iter.descriptors_),
           kind_mask_(iter.kind_mask_),
@@ skipping 4123 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_