Reified metadata in the VM

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, 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 "include/dart_api.h"
 
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
@@ skipping 4330 matching lines @@
   if (!ret_obj.IsNull() && !ret_obj.IsInstance()) {
     FATAL1("Return value check failed: saw '%s' expected a dart Instance.",
            ret_obj.ToCString());
   }
   NoGCScope no_gc_scope;
   NativeArguments* arguments = reinterpret_cast<NativeArguments*>(args);
   arguments->SetReturn(ret_obj);
 }
 
 
+// --- Metadata ----
+
+DART_EXPORT Dart_Handle Dart_GetMetadata(Dart_Handle object) {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  DARTSCOPE(isolate);
+  Object& obj = Object::Handle(isolate, Api::UnwrapHandle(object));
+  Class& cls = Class::Handle(isolate);
+  if (obj.IsClass()) {
+    cls ^= obj.raw();
+  } else if (obj.IsFunction()) {
+    cls = Function::Cast(obj).origin();
+  } else if (obj.IsField()) {
+    cls = Field::Cast(obj).origin();
+  } else {
+    return Api::NewHandle(isolate, Array::New(0));

[siva, 2013/06/12 00:16:52]

return Api::NewHandle(isolate, Object::empty_array().raw());

[hausner, 2013/06/12 01:10:05]

Done.

+  }
+  const Library& lib = Library::Handle(cls.library());
+  obj = lib.GetMetadata(obj);
+  return Api::NewHandle(isolate, obj.raw());

[siva, 2013/06/12 00:16:52]

why not:

return Api::NewHandle(isolate, lib.GetMetadata(obj));

would avoid an unnecessary call to SetRaw().

[hausner, 2013/06/12 01:10:05]

Done.

+}
+
+
 // --- Scripts and Libraries ---
 
 
 DART_EXPORT Dart_Handle Dart_SetLibraryTagHandler(
     Dart_LibraryTagHandler handler) {
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   isolate->set_library_tag_handler(handler);
   return Api::Success();
 }
@@ skipping 476 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success();
 }
 
 }  // namespace dart