Prevent clang from doing tail-call elimination in DartEntry::InvokeClosure.

runtime/vm/dart_entry.cc

Index: runtime/vm/dart_entry.cc
diff --git a/runtime/vm/dart_entry.cc b/runtime/vm/dart_entry.cc
index abb3e5db371e4c8dd5b4433b7c0aff9c9f6e7fab..3a53dcc641ba59fc60df6f3b45f19d76a8f7887f 100644
--- a/runtime/vm/dart_entry.cc
+++ b/runtime/vm/dart_entry.cc
@@ -192,7 +192,12 @@ RawObject* DartEntry::InvokeClosure(const Array& arguments,
         ASSERT(getter_result.IsNull() || getter_result.IsInstance());
 
         arguments.SetAt(0, getter_result);
-        return InvokeClosure(arguments, arguments_descriptor);
+        // This otherwise unnecessary handle is used to prevent clang from

[Florian Schneider, 2016/01/15 00:46:46]

Should we only do this in simulator builds? i.e. #ifdef USING_SIMULATOR

[rmacnak, 2016/01/15 01:00:07]

We need a stack overflow check for all configuration with --no-lazy-dispatchers,
not just the simulators.

+        // doing tail call elimination, which would make the stack overflow
+        // check above ineffective.
+        Object& result = Object::Handle(InvokeClosure(arguments,
+                                                      arguments_descriptor));
+        return result.raw();
       }
       cls = cls.SuperClass();
     }