Fix evaluation in frames with _private variable names.

runtime/vm/debugger.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/debugger.h"
 
 #include "include/dart_api.h"
 
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 1010 matching lines @@
     intptr_t ignore;
     VariableAt(i, &var_name, &ignore, &ignore, &value);
     if (var_name.Equals(Symbols::This())) {
       return value.raw();
     }
   }
   return Object::null();
 }
 
 
+bool IsPrivateVariableName(const String& var_name) {

[rmacnak, 2015/10/07 18:06:21]

Library::IsPrivate already exists and handles more edge cases

+  return (var_name.Length() >= 1) && (var_name.CharAt(0) == '_');
+}
+
+
 RawObject* ActivationFrame::Evaluate(const String& expr) {
   GetDescIndices();
   const GrowableObjectArray& param_names =
       GrowableObjectArray::Handle(GrowableObjectArray::New());
   const GrowableObjectArray& param_values =
       GrowableObjectArray::Handle(GrowableObjectArray::New());
   String& name = String::Handle();
   Object& value = Instance::Handle();
   intptr_t num_variables = desc_indices_.length();
   for (intptr_t i = 0; i < num_variables; i++) {
     intptr_t ignore;
     VariableAt(i, &name, &ignore, &ignore, &value);
     if (!name.Equals(Symbols::This())) {
+      if (IsPrivateVariableName(name)) {
+        name = String::IdentifierPrettyName(name);
+      }
       param_names.Add(name);
       param_values.Add(value);
     }
   }
 
   if (function().is_static()) {
     const Class& cls = Class::Handle(function().Owner());
     return cls.Evaluate(expr,
                         Array::Handle(Array::MakeArray(param_names)),
                         Array::Handle(Array::MakeArray(param_values)));
@@ skipping 2172 matching lines @@
 }
 
 
 void Debugger::RegisterCodeBreakpoint(CodeBreakpoint* bpt) {
   ASSERT(bpt->next() == NULL);
   bpt->set_next(code_breakpoints_);
   code_breakpoints_ = bpt;
 }
 
 }  // namespace dart