Add type check tracing (--trace_type_checks). Inline type checks with class types that have only ...

runtime/lib/error.cc

Index: runtime/lib/error.cc
===================================================================
--- runtime/lib/error.cc	(revision 1367)
+++ runtime/lib/error.cc	(working copy)
@@ -12,6 +12,7 @@
 
 namespace dart {
 
+DEFINE_FLAG(bool, trace_type_checks, false, "Trace runtime type checks.");
 DECLARE_FLAG(bool, print_stack_trace_at_throw);
 
 
@@ -213,6 +214,17 @@
     ThrowTypeError(location, src_type_name, dst_type_name, dst_name);
     UNREACHABLE();
   }
+
+  if (FLAG_trace_type_checks) {
+    Class& cls = Class::Handle(src_instance.clazz());
+    // TODO(regis): Remove once all classes finalized.
+    if (cls.is_finalized())  {
+      OS::Print("TypeCheck '%s' vs '%s'\n",
+          String::Handle(Type::Handle(src_instance.GetType()).Name()).
+              ToCString(),
+          String::Handle(dst_type.Name()).ToCString());
+    }
+  }
   arguments.SetReturn(src_instance);
 }