Implement metadata as an internal native. Be honest about which mirrors don't yet support metadata …

runtime/lib/mirrors.cc

 // Copyright (c) 2012, 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 "include/dart_debugger_api.h"
 #include "include/dart_mirrors_api.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"  // TODO(11742): Remove with CreateMirrorRef.
 #include "vm/bootstrap_natives.h"
@@ skipping 613 matching lines @@
     Dart_False(),
   };
   Dart_Handle mirror =
       Dart_New(mirror_type, Dart_Null(), ARRAY_SIZE(args), args);
   return mirror;
 }
 
 
 static Dart_Handle CreateVariableMirror(Dart_Handle var,
                                         Dart_Handle var_name,
-                                        Dart_Handle lib_mirror) {
+                                        Dart_Handle owner_mirror) {
   ASSERT(Dart_IsVariable(var));
   Dart_Handle cls_name = NewString("_LocalVariableMirrorImpl");
   Dart_Handle type = Dart_GetType(MirrorLib(), cls_name, 0, NULL);
   if (Dart_IsError(type)) {
     return type;
   }
 
   bool is_static = false;
   bool is_final = false;
 
   Dart_Handle result = Dart_VariableIsStatic(var, &is_static);
   if (Dart_IsError(result)) {
     return result;
   }
   result = Dart_VariableIsFinal(var, &is_final);
   if (Dart_IsError(result)) {
     return result;
   }
 
   Dart_Handle var_type = Dart_VariableType(var);
   if (Dart_IsError(var_type)) {
     return var_type;
   }
 
   Dart_Handle args[] = {
+    CreateMirrorReference(var),
     var_name,
-    lib_mirror,
+    owner_mirror,
     CreateLazyMirror(var_type),
     Dart_NewBoolean(is_static),
     Dart_NewBoolean(is_final),
   };
   Dart_Handle mirror = Dart_New(type, Dart_Null(), ARRAY_SIZE(args), args);
   return mirror;
 }
 
 
 static Dart_Handle AddMemberClasses(Dart_Handle map,
@@ skipping 433 matching lines @@
                                          name_handle,
                                          lib_handle,
                                          lib_mirror);
   if (Dart_IsError(result)) {
     Dart_PropagateError(result);
   }
   Dart_SetReturnValue(args, result);
   Dart_ExitScope();
 }
 
-void NATIVE_ENTRY_FUNCTION(Mirrors_metadata)(Dart_NativeArguments args) {
-  Dart_EnterScope();
-  Dart_Handle mirror = Dart_GetNativeArgument(args, 0);
-
-  Dart_Handle reflectee = UnwrapMirror(mirror);
-  Dart_Handle result = Dart_GetMetadata(reflectee);
-  if (Dart_IsError(result)) {
-    Dart_PropagateError(result);
-  }
-  ASSERT(Dart_IsList(result));
-  Dart_SetReturnValue(args, result);
-  Dart_ExitScope();
-}
-
 
+DEFINE_NATIVE_ENTRY(DeclarationMirror_metadata, 1) {
+  const MirrorReference& decl_ref =
+      MirrorReference::CheckedHandle(arguments->NativeArgAt(0));
+  const Object& decl = Object::Handle(decl_ref.referent());
+
+  Class& klass = Class::Handle();
+  if (decl.IsClass()) {
+    klass ^= decl.raw();
+  } else if (decl.IsFunction()) {
+    klass = Function::Cast(decl).origin();
+  } else if (decl.IsField()) {
+    klass = Field::Cast(decl).origin();
+  } else {
+    return Object::empty_array().raw();
+  }
+
+  const Library& library = Library::Handle(klass.library());
+  return library.GetMetadata(decl);
+}
+
+
 void HandleMirrorsMessage(Isolate* isolate,
                           Dart_Port reply_port,
                           const Instance& message) {
   UNIMPLEMENTED();
 }
 
 
 // TODO(11742): This is transitional.
 static RawInstance* Reflect(const Instance& reflectee) {
   Isolate* isolate = Isolate::Current();
@@ skipping 677 matching lines @@
 
 DEFINE_NATIVE_ENTRY(MethodMirror_name, 1) {
   const MirrorReference& func_ref =
       MirrorReference::CheckedHandle(arguments->NativeArgAt(0));
   Function& func = Function::Handle();
   func ^= func_ref.referent();
   return func.UserVisibleName();
 }
 
 }  // namespace dart