Adding index accessor counter

Change-Id: I7e833c3b06cfb3ff9eda663c2bee4981013744b0

Adding index accessor counter

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ic353c11fa0f430537819387d17eedeec5466d9cc
Bug: 
Reviewed-on: https://chromium-review.googlesource.com/741169Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Natalie Silvanovich <natashenka@google.com>
Cr-Commit-Position: refs/heads/master@{#49061}

include/v8.h

@@ -7053,6 +7053,7 @@ class V8_EXPORT Isolate {
     kConstructorNonUndefinedPrimitiveReturn = 39,
     kLabeledExpressionStatement = 40,
     kLineOrParagraphSeparatorAsLineTerminator = 41,
+    kIndexAccessor = 42,
 
     // If you add new values here, you'll also need to update Chromium's:
     // UseCounter.h, V8PerIsolateData.cpp, histograms.xml

src/lookup.cc

@@ -630,6 +630,7 @@ void LookupIterator::TransitionToAccessorPair(Handle<Object> pair,
 
   if (IsElement()) {
     // TODO(verwaest): Move code into the element accessor.
+    isolate_->CountUsage(v8::Isolate::kIndexAccessor);
     Handle<SeededNumberDictionary> dictionary =
         JSObject::NormalizeElements(receiver);
 

src/objects.cc

@@ -6775,7 +6775,6 @@ MaybeHandle<Object> JSReceiver::DefineProperties(Isolate* isolate,
   return object;
 }
 
-
 // static
 Maybe<bool> JSReceiver::DefineOwnProperty(Isolate* isolate,
                                           Handle<JSReceiver> object,

test/cctest/test-usecounters.cc

@@ -142,6 +142,55 @@ TEST(LabeledExpressionStatement) {
   CHECK_EQ(2, use_counts[v8::Isolate::kLabeledExpressionStatement]);
 }
 
+TEST(IndexAccessorUseCount) {
+  i::FLAG_harmony_strict_legacy_accessor_builtins = false;
+  v8::Isolate* isolate = CcTest::isolate();
+  v8::HandleScope scope(isolate);
+  LocalContext env;
+  int use_counts[v8::Isolate::kUseCounterFeatureCount] = {};
+  global_use_counts = use_counts;
+  CcTest::isolate()->SetUseCounterCallback(MockUseCounterCallback);
+
+  // Adding accessor to named property does not increment kIndexAccessor
+  CompileRun(
+      "var a = {};"
+      "function dummy(){}"
+      "Object.defineProperty(a, 'test', { get: dummy, set: dummy });");
+  CHECK_EQ(0, use_counts[v8::Isolate::kIndexAccessor]);
+
+  // Setting index to value does not increment kIndexAccessor
+  CompileRun(
+      "var a = {};"
+      "Object.defineProperty(a, '0', { value: 0 });");
+  CHECK_EQ(0, use_counts[v8::Isolate::kIndexAccessor]);
+
+  // Non-integer number index not increment kIndexAccessor
+  CompileRun(
+      "var a = {};"
+      "Object.defineProperty(a, '2.5', { value: 0 });");
+  CHECK_EQ(0, use_counts[v8::Isolate::kIndexAccessor]);
+
+  // Setting index accessor increments count
+  CompileRun(
+      "var a = {};"
+      "function dummy(){}"
+      "Object.defineProperty(a, '0', { get : dummy, set : dummy });");
+  CHECK_EQ(1, use_counts[v8::Isolate::kIndexAccessor]);
+
+  // Setting index accessor on array increments count
+  CompileRun(
+      "var a = [];"
+      "function dummy(){}"
+      "Object.defineProperty(a, '0', { get : dummy, set : dummy });");
+  CHECK_EQ(2, use_counts[v8::Isolate::kIndexAccessor]);
+
+  // __defineGetter__ increments count
+  CompileRun(
+      "var a = [];"
+      "function dummy(){}"
+      "a.__defineGetter__('0', dummy);");
+  CHECK_EQ(3, use_counts[v8::Isolate::kIndexAccessor]);
+}
 }  // namespace test_usecounters
 }  // namespace internal
 }  // namespace v8