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

runtime/lib/error.cc

 // Copyright (c) 2011, 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 "lib/error.h"
 
 #include "vm/bootstrap_natives.h"
 #include "vm/exceptions.h"
 #include "vm/object_store.h"
 #include "vm/runtime_entry.h"
 #include "vm/stack_frame.h"
 
 namespace dart {
 
+DEFINE_FLAG(bool, trace_type_checks, false, "Trace runtime type checks.");
 DECLARE_FLAG(bool, print_stack_trace_at_throw);
 
 
 // Static helpers for allocating, initializing, and throwing an error instance.
 
 // Return the script of the Dart function that called the native entry or the
 // runtime entry. The frame iterator points to the callee.
 static RawScript* GetCallerScript(DartFrameIterator* iterator) {
   DartFrame* caller_frame = iterator->NextFrame();
   ASSERT(caller_frame != NULL);
@@ skipping 181 matching lines @@
       // Instantiate dst_type before reporting the error.
       const Type& instantiated_dst_type = Type::Handle(
           dst_type.InstantiateFrom(dst_type_instantiator, 0));
       dst_type_name = instantiated_dst_type.Name();
     } else {
       dst_type_name = dst_type.Name();
     }
     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);
 }
 
 
 // Report that the type of the given object is not bool in conditional context.
 // Arg0: index of the token of the assignment (source location).
 // Arg1: bad object.
 // Return value: none, throws a TypeError.
 DEFINE_RUNTIME_ENTRY(ConditionTypeError, 2) {
   ASSERT(arguments.Count() ==
@@ skipping 53 matching lines @@
         dst_type_name = element_type.Name();
       }
       const String& dst_name = String::Handle(String::New(buf));
       ThrowTypeError(location, src_type_name, dst_type_name, dst_name);
       UNREACHABLE();
     }
   }
 }
 
 }  // namespace dart