Add StackTrace.current getter.

runtime/lib/stacktrace.cc

Index: runtime/lib/stacktrace.cc
diff --git a/runtime/lib/stacktrace.cc b/runtime/lib/stacktrace.cc
index 6175b24b4d18d841ce132233347e27e3053439a3..4df36428856f07c9ae5f2a6d702aae90bfec9bd8 100644
--- a/runtime/lib/stacktrace.cc
+++ b/runtime/lib/stacktrace.cc
@@ -48,4 +48,20 @@ void _printCurrentStacktrace() {
   OS::PrintErr("=== Current Trace:\n%s===\n", stacktrace.ToCString());
 }
 
+DEFINE_NATIVE_ENTRY(StackTrace_current, 0) {
+  const GrowableObjectArray& code_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  const GrowableObjectArray& pc_offset_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  // Skip the StackFrame.current frame.
+  IterateFrames(code_list, pc_offset_list);
+  const Array& code_array = Array::Handle(Array::MakeArray(code_list));
+  const Array& pc_offset_array =
+      Array::Handle(Array::MakeArray(pc_offset_list));
+  const Stacktrace& stacktrace = Stacktrace::Handle(
+      Stacktrace::New(code_array, pc_offset_array));
+  return stacktrace.raw();
+}

[Lasse Reichstein Nielsen, 2015/11/18 10:11:38]

The VM even has the option of dropping the first stack frame, so
`StackTrace.current` itself won't show up in the captured trace. I think we
should do that. It's not as easy in JS, but that shouldn't prevent us from doing
the right thing here.

+
+
 }  // namespace dart