Use clustered serialization for full snapshots.

runtime/lib/stacktrace.cc

 // Copyright (c) 2013, 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 "lib/stacktrace.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
@@ skipping 43 matching lines @@
 // An utility method for convenient printing of dart stack traces when
 // inside 'gdb'. Note: This function will only work when there is a
 // valid exit frame information. It will not work when a breakpoint is
 // set in dart code and control is got inside 'gdb' without going through
 // the runtime or native transition stub.
 void _printCurrentStacktrace() {
   const Stacktrace& stacktrace = GetCurrentStacktrace(0);
   OS::PrintErr("=== Current Trace:\n%s===\n", stacktrace.ToCString());
 }
 
+// Like _printCurrentStacktrace, but works in a NoSafepointScope.
+void _printCurrentStacktraceNoSafepoint() {
+  StackFrameIterator frames(StackFrameIterator::kDontValidateFrames);
+  StackFrame* frame = frames.NextFrame();
+  while (frame != NULL) {
+    OS::Print("%s\n", frame->ToCString());
+    frame = frames.NextFrame();
+  }
+}

[siva, 2016/06/30 00:06:07]

Do we need the other version, why not make your version
_printCurrentStacktrace() and get rid of the existing version.

[rmacnak, 2016/06/30 01:39:21]

The existing version is often preferable when it works because you get line
numbers. The new version is helpful for lower-level bugs.

+
 DEFINE_NATIVE_ENTRY(StackTrace_current, 0) {
   const Stacktrace& stacktrace = GetCurrentStacktrace(1);
   return stacktrace.raw();
 }
 
 }  // namespace dart