From 670a0345ca722c2c56c4aceda5a70c74ea9f6ffd Mon Sep 17 00:00:00 2001
From: "rmacnak@google.com" <rmacnak@google.com>
Date: Thu, 25 Jul 2013 20:49:59 +0000
Subject: [PATCH] Wrap lazy compilation errors when parsing metadata. Addresses
 the poor error reporting in issue 12027.

R=asiva@google.com

Review URL: https://codereview.chromium.org//20458002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@25498 260f80e4-7a28-3924-810f-c04153c831b5
---
 runtime/lib/mirrors.cc                        | 60 ++++++++++---------
 .../vm/dart/isolate_mirror_local_test.dart    |  2 +
 2 files changed, 34 insertions(+), 28 deletions(-)

diff --git a/runtime/lib/mirrors.cc b/runtime/lib/mirrors.cc
index 0d1a4aff997..c9c6817889a 100644
--- a/runtime/lib/mirrors.cc
+++ b/runtime/lib/mirrors.cc
@@ -981,34 +981,6 @@ void NATIVE_ENTRY_FUNCTION(Mirrors_makeLocalClassMirror)(
 }
 
 
-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();
-}
-
-
 static void ThrowMirroredCompilationError(const String& message) {
   Array& args = Array::Handle(Array::New(1));
   args.SetAt(0, message);
@@ -1031,6 +1003,38 @@ static void ThrowInvokeError(const Error& error) {
 }
 
 
+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());
+  const Object& metadata = Object::Handle(library.GetMetadata(decl));
+  if (metadata.IsError()) {
+    ThrowInvokeError(Error::Cast(metadata));
+  }
+  return metadata.raw();
+}
+
+
+void HandleMirrorsMessage(Isolate* isolate,
+                          Dart_Port reply_port,
+                          const Instance& message) {
+  UNIMPLEMENTED();
+}
+
+
 static bool FieldIsUninitialized(const Field& field) {
   ASSERT(!field.IsNull());
 
diff --git a/runtime/tests/vm/dart/isolate_mirror_local_test.dart b/runtime/tests/vm/dart/isolate_mirror_local_test.dart
index cc7d3e6f783..54241c4ca17 100644
--- a/runtime/tests/vm/dart/isolate_mirror_local_test.dart
+++ b/runtime/tests/vm/dart/isolate_mirror_local_test.dart
@@ -407,6 +407,7 @@ class MySuperClass {
 class MyInterface {
 }
 
+@notDefined
 class MyClass extends MySuperClass implements MyInterface {
   MyClass(this.value) {}
   MyClass.named() {}
@@ -445,6 +446,7 @@ void testCustomInstanceMirror(InstanceMirror mirror) {
   Expect.equals(const Symbol('isolate_mirror_local_test'), cls.owner.simpleName);
   Expect.isTrue(cls.isClass);
   Expect.equals(const Symbol('MyInterface'), cls.superinterfaces[0].simpleName);
+  Expect.throws(() => cls.metadata, (e) => e is MirroredCompilationError, 'Bad metadata');
   // TODO(ahe): toString() test disabled for now as Symbols are 100% opaque.
   // Expect.equals("ClassMirror on 'MyClass'", cls.toString());