Include field reference with implicit getter / setter functions

- When printing implicit getter or setter functions, include the field that the implicit functions were generated for.
- Display field on function view in Observatory.
- Service unit test.

R=rmacnak@google.com

Review URL: https://codereview.chromium.org/1440753002 .

runtime/observatory/lib/src/elements/function_view.html

@@ -46,6 +46,14 @@
             <any-service-ref ref="{{ function.dartOwner }}"></any-service-ref>
           </div>
         </div>
+        <template if="{{ function.field != null }}">
+          <div class="memberItem">
+            <div class="memberName">field</div>
+            <div class="memberValue">
+              <any-service-ref ref="{{ function.field }}"></any-service-ref>
+            </div>
+          </div>
+        </template>
         <div class="memberItem">
           <div class="memberName">script</div>
           <div class="memberValue">

runtime/observatory/lib/src/service/object.dart

@@ -2575,6 +2575,7 @@ class ServiceFunction extends HeapObject with Coverage {
   @observable bool isDart;
   @observable ProfileFunction profile;
   @observable Instance icDataArray;
+  @observable Field field;
 
   bool get canCache => true;
   bool get immutable => false;
@@ -2622,6 +2623,7 @@ class ServiceFunction extends HeapObject with Coverage {
     deoptimizations = map['_deoptimizations'];
     usageCounter = map['_usageCounter'];
     icDataArray = map['_icDataArray'];
+    field = map['_field'];
   }
 }
 

runtime/observatory/tests/service/implicit_getter_setter_test.dart

@@ -0,0 +1,69 @@
+// Copyright (c) 2015, 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.
+
+library implicit_getter_setter_test;
+
+import 'package:observatory/service_io.dart';
+import 'package:unittest/unittest.dart';
+import 'test_helper.dart';
+
+class A {
+  double field = 0.0;
+}
+
+script() {
+  for (int i = 0; i < 10; i++) {
+    new A();
+  }
+}
+
+testGetter(Isolate isolate) async {
+  Library rootLibrary = await isolate.rootLibrary.load();
+  expect(rootLibrary.classes.length, equals(1));
+  Class classA = await rootLibrary.classes[0].load();
+  expect(classA.name, equals('A'));
+  // Find getter.
+  ServiceFunction getterFunc;
+  for (ServiceFunction function in classA.functions) {
+    if (function.name == 'field') {
+      getterFunc = function;
+      break;
+    }
+  }
+  expect(getterFunc, isNotNull);
+  await getterFunc.load();
+  Field field = await getterFunc.field.load();
+  expect(field, isNotNull);
+  expect(field.name, equals('field'));
+  Class classDouble = await field.guardClass.load();
+  expect(classDouble.name, equals('_Double'));
+}
+
+
+testSetter(Isolate isolate) async {
+  Library rootLibrary = await isolate.rootLibrary.load();
+  expect(rootLibrary.classes.length, equals(1));
+  Class classA = await rootLibrary.classes[0].load();
+  expect(classA.name, equals('A'));
+  // Find setter.
+  ServiceFunction setterFunc;
+  for (ServiceFunction function in classA.functions) {
+    if (function.name == 'field=') {
+      setterFunc = function;
+      break;
+    }
+  }
+  expect(setterFunc, isNotNull);
+  await setterFunc.load();
+  Field field = await setterFunc.field.load();
+  expect(field, isNotNull);
+  expect(field.name, equals('field'));
+  Class classDouble = await field.guardClass.load();
+  expect(classDouble.name, equals('_Double'));
+}
+
+
+var tests = [testGetter, testSetter];
+
+main(args) => runIsolateTests(args, tests, testeeBefore: script);

runtime/vm/object.cc

@@ -5516,6 +5516,27 @@ void Function::set_saved_args_desc(const Array& value) const {
 }
 
 
+RawField* Function::LookupImplicitGetterSetterField() const {
+  ASSERT((kind() == RawFunction::kImplicitGetter) ||
+         (kind() == RawFunction::kImplicitSetter) ||
+         (kind() == RawFunction::kImplicitStaticFinalGetter));
+  const Class& owner = Class::Handle(Owner());
+  ASSERT(!owner.IsNull());
+  const Array& fields = Array::Handle(owner.fields());
+  ASSERT(!fields.IsNull());
+  Field& field = Field::Handle();
+  for (intptr_t i = 0; i < fields.Length(); i++) {
+    field ^= fields.At(i);
+    ASSERT(!field.IsNull());
+    if (field.token_pos() == token_pos()) {
+      return field.raw();
+    }
+  }
+  return Field::null();
+}
+
+
+
 RawFunction* Function::parent_function() const {
   if (IsClosureFunction()) {
     const Object& obj = Object::Handle(raw_ptr()->data_);
@@ -7272,6 +7293,14 @@ void Function::PrintJSONImpl(JSONStream* stream, bool ref) const {
   jsobj.AddProperty("_optimizedCallSiteCount", optimized_call_site_count());
   jsobj.AddProperty("_deoptimizations",
                     static_cast<intptr_t>(deoptimization_counter()));
+  if ((kind() == RawFunction::kImplicitGetter) ||
+      (kind() == RawFunction::kImplicitSetter) ||
+      (kind() == RawFunction::kImplicitStaticFinalGetter)) {
+    const Field& field = Field::Handle(LookupImplicitGetterSetterField());
+    if (!field.IsNull()) {
+      jsobj.AddProperty("_field", field);
+    }
+  }
 
   const Script& script = Script::Handle(this->script());
   if (!script.IsNull()) {

runtime/vm/object.h

@@ -2197,6 +2197,8 @@ class Function : public Object {
   RawContextScope* context_scope() const;
   void set_context_scope(const ContextScope& value) const;
 
+  RawField* LookupImplicitGetterSetterField() const;
+
   // Enclosing function of this local function.
   RawFunction* parent_function() const;