Allow creating DartFrameIterator using explicit last_fp value (instead of always expecting it from …

runtime/vm/stack_frame.cc

 // Copyright (c) 2011, 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/stack_frame.h"
 
 #include "vm/assembler_macros.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
@@ skipping 152 matching lines @@
   }
   return (LookupDartCode() != Code::null());
 }
 
 
 StackFrameIterator::StackFrameIterator(bool validate)
     : validate_(validate), entry_(), exit_(), current_frame_(NULL) {
   SetupLastExitFrameData();  // Setup data for last exit frame.
 }
 
+StackFrameIterator::StackFrameIterator(uword last_fp, bool validate)
+    : validate_(validate), entry_(), exit_(), current_frame_(NULL) {
+  frames_.fp_ = last_fp;
+}
+
 
 StackFrame* StackFrameIterator::NextFrame() {
   // When we are at the start of iteration after having created an
   // iterator object current_frame_ will be NULL as we haven't seen
   // any frames yet. At this point if NextFrame is called it tries
   // to set up the next exit frame by reading the top_exit_frame_info
   // from the isolate. If we do not have any dart invocations yet
   // top_exit_frame_info will be 0 and so we would return NULL.
 
   // current_frame_ will also be NULL, when we are at the end of having
@@ skipping 55 matching lines @@
 EntryFrame* StackFrameIterator::NextEntryFrame() {
   ASSERT(!frames_.HasNext());
   entry_.sp_ = frames_.sp_;
   entry_.fp_ = frames_.fp_;
   SetupNextExitFrameData();  // Setup data for next exit frame in chain.
   ASSERT(entry_.IsValid());
   return &entry_;
 }
 
 }  // namespace dart