Track the 'awaiter return' call stack use it to detect uncaught exceptions in async functions

runtime/vm/scopes.cc

 // 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.
 
 #include "vm/scopes.h"
 
 #include "vm/object.h"
 #include "vm/stack_frame.h"
 #include "vm/symbols.h"
 
@@ skipping 246 matching lines @@
 }
 
 
 // The parser creates internal variables that start with ":"
 static bool IsFilteredIdentifier(const String& str) {
   ASSERT(str.Length() > 0);
   if (str.raw() == Symbols::AsyncOperation().raw()) {
     // Keep :async_op for asynchronous debugging.
     return false;
   }
+  if (str.raw() == Symbols::AsyncCompleter().raw()) {
+    // Keep :async_completer for asynchronous debugging.
+    return false;
+  }
+  if (str.raw() == Symbols::ControllerStream().raw()) {
+    // Keep :controller_stream for asynchronous debugging.
+    return false;
+  }
+  if (str.raw() == Symbols::AwaitJumpVar().raw()) {
+    // Keep :await_jump_var for asynchronous debugging.
+    return false;
+  }
   return str.CharAt(0) == ':';
 }
 
 
 RawLocalVarDescriptors* LocalScope::GetVarDescriptors(const Function& func) {
   GrowableArray<VarDesc> vars(8);
   // First enter all variables from scopes of outer functions.
   const ContextScope& context_scope =
       ContextScope::Handle(func.context_scope());
   if (!context_scope.IsNull()) {
@@ skipping 409 matching lines @@
     return fixed_parameter_count - (index() - kParamEndSlotFromFp);
   } else {
     // Shift negative indexes so that the lowest one is 0 (they are still
     // non-positive).
     return fixed_parameter_count - (index() - kFirstLocalSlotFromFp);
   }
 }
 
 
 }  // namespace dart