Fix asserts in StackFrameIterator which were effectively disabled

runtime/lib/errors.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/bootstrap_natives.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
 #include "vm/symbols.h"
@@ skipping 57 matching lines @@
   // No need to type check the arguments. This function can only be called
   // internally from the VM.
   const TokenPosition assertion_start =
       TokenPosition(Smi::CheckedHandle(arguments->NativeArgAt(0)).Value());
   const TokenPosition assertion_end =
       TokenPosition(Smi::CheckedHandle(arguments->NativeArgAt(1)).Value());
 
   const Instance& message = Instance::CheckedHandle(arguments->NativeArgAt(2));
   const Array& args = Array::Handle(Array::New(5));
 
-  DartFrameIterator iterator;
+  DartFrameIterator iterator(thread, false);

[Vyacheslav Egorov (Google), 2017/05/01 15:54:38]

I suggest that this false needs a name. 

thread, kNoCrossThreadIteration
thread, kAllowCrossThreadIteration

reads better than

thread, false
thread, true

[kustermann, 2017/05/02 07:11:18]

Made both bools an enum

   iterator.NextFrame();  // Skip native call.
   const Script& script = Script::Handle(FindScript(&iterator));
 
   // Initialize argument 'failed_assertion' with source snippet.
   intptr_t from_line, from_column;
   script.GetTokenLocation(assertion_start, &from_line, &from_column);
   intptr_t to_line, to_column;
   script.GetTokenLocation(assertion_end, &to_line, &to_column);
   // The snippet will extract the correct assertion code even if the source
   // is generated.
@@ skipping 43 matching lines @@
 // Allocate and throw a new FallThroughError.
 // Arg0: index of the case clause token into which we fall through.
 // Return value: none, throws an exception.
 DEFINE_NATIVE_ENTRY(FallThroughError_throwNew, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, smi_pos, arguments->NativeArgAt(0));
   TokenPosition fallthrough_pos = TokenPosition(smi_pos.Value());
 
   const Array& args = Array::Handle(Array::New(2));
 
   // Initialize 'url' and 'line' arguments.
-  DartFrameIterator iterator;
+  DartFrameIterator iterator(thread, false);
   iterator.NextFrame();  // Skip native call.
   const Script& script = Script::Handle(Exceptions::GetCallerScript(&iterator));
   args.SetAt(0, String::Handle(script.url()));
   intptr_t line;
   script.GetTokenLocation(fallthrough_pos, &line, NULL);
   args.SetAt(1, Smi::Handle(Smi::New(line)));
 
   Exceptions::ThrowByType(Exceptions::kFallThrough, args);
   UNREACHABLE();
   return Object::null();
 }
 
 
 // Allocate and throw a new AbstractClassInstantiationError.
 // Arg0: Token position of allocation statement.
 // Arg1: class name of the abstract class that cannot be instantiated.
 // Return value: none, throws an exception.
 DEFINE_NATIVE_ENTRY(AbstractClassInstantiationError_throwNew, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, smi_pos, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(String, class_name, arguments->NativeArgAt(1));
   TokenPosition error_pos = TokenPosition(smi_pos.Value());
 
   const Array& args = Array::Handle(Array::New(3));
 
   // Initialize 'className', 'url' and 'line' arguments.
-  DartFrameIterator iterator;
+  DartFrameIterator iterator(thread, false);
   iterator.NextFrame();  // Skip native call.
   const Script& script = Script::Handle(Exceptions::GetCallerScript(&iterator));
   args.SetAt(0, class_name);
   args.SetAt(1, String::Handle(script.url()));
   intptr_t line;
   script.GetTokenLocation(error_pos, &line, NULL);
   args.SetAt(2, Smi::Handle(Smi::New(line)));
 
   Exceptions::ThrowByType(Exceptions::kAbstractClassInstantiation, args);
   UNREACHABLE();
   return Object::null();
 }
 
 // Rethrow an error with a stacktrace.
 DEFINE_NATIVE_ENTRY(Async_rethrow, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, error, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, stacktrace, arguments->NativeArgAt(1));
   Exceptions::ReThrow(thread, error, stacktrace);
   return Object::null();
 }
 
 }  // namespace dart