From 68c91ea30164e6a3dbc1dc45f68a5c9896a84aa9 Mon Sep 17 00:00:00 2001
From: "ishell@chromium.org"
 <ishell@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Thu, 20 Mar 2014 13:16:19 +0000
Subject: [PATCH] ArrayShift builtin handlified.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/206423002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20124 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/builtins.cc | 41 ++++++++++++++++++++---------------------
 src/elements.cc | 13 +++++++++++++
 src/elements.h  |  7 +++++++
 3 files changed, 40 insertions(+), 21 deletions(-)

diff --git a/src/builtins.cc b/src/builtins.cc
index 6afd442..be9051c 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -367,6 +367,7 @@ static inline Handle<Object> EnsureJSArrayWithWritableFastElementsWrapper(
 }
 
 
+// TODO(ishell): Handlify when all Array* builtins are handlified.
 static inline bool IsJSArrayFastElementMovingAllowed(Heap* heap,
                                                      JSArray* receiver) {
   if (!FLAG_clever_optimizations) return false;
@@ -575,19 +576,19 @@ BUILTIN(ArrayPop) {
 
 
 BUILTIN(ArrayShift) {
+  HandleScope scope(isolate);
   Heap* heap = isolate->heap();
-  Object* receiver = *args.receiver();
-  FixedArrayBase* elms_obj;
-  MaybeObject* maybe_elms_obj =
-      EnsureJSArrayWithWritableFastElements(heap, receiver, NULL, 0);
-  if (maybe_elms_obj == NULL)
-      return CallJsBuiltin(isolate, "ArrayShift", args);
-  if (!maybe_elms_obj->To(&elms_obj)) return maybe_elms_obj;
-
-  if (!IsJSArrayFastElementMovingAllowed(heap, JSArray::cast(receiver))) {
+  Handle<Object> receiver = args.receiver();
+  Handle<Object> elms_or_null =
+      EnsureJSArrayWithWritableFastElementsWrapper(isolate, receiver, NULL, 0);
+  RETURN_IF_EMPTY_HANDLE(isolate, elms_or_null);
+  if ((*elms_or_null == NULL) ||
+      !IsJSArrayFastElementMovingAllowed(heap,
+                                         *Handle<JSArray>::cast(receiver))) {
     return CallJsBuiltin(isolate, "ArrayShift", args);
   }
-  JSArray* array = JSArray::cast(receiver);
+  Handle<FixedArrayBase> elms_obj = Handle<FixedArrayBase>::cast(elms_or_null);
+  Handle<JSArray> array = Handle<JSArray>::cast(receiver);
   ASSERT(!array->map()->is_observed());
 
   int len = Smi::cast(array->length())->value();
@@ -595,25 +596,23 @@ BUILTIN(ArrayShift) {
 
   // Get first element
   ElementsAccessor* accessor = array->GetElementsAccessor();
-  Object* first;
-  MaybeObject* maybe_first = accessor->Get(receiver, array, 0, elms_obj);
-  if (!maybe_first->To(&first)) return maybe_first;
+  Handle<Object> first = accessor->Get(receiver, array, 0, elms_obj);
   if (first->IsTheHole()) {
-    first = heap->undefined_value();
+    first = isolate->factory()->undefined_value();
   }
 
-  if (!heap->lo_space()->Contains(elms_obj)) {
-    array->set_elements(LeftTrimFixedArray(heap, elms_obj, 1));
+  if (!heap->lo_space()->Contains(*elms_obj)) {
+    array->set_elements(LeftTrimFixedArray(heap, *elms_obj, 1));
   } else {
     // Shift the elements.
     if (elms_obj->IsFixedArray()) {
-      FixedArray* elms = FixedArray::cast(elms_obj);
+      Handle<FixedArray> elms = Handle<FixedArray>::cast(elms_obj);
       DisallowHeapAllocation no_gc;
-      heap->MoveElements(elms, 0, 1, len - 1);
+      heap->MoveElements(*elms, 0, 1, len - 1);
       elms->set(len - 1, heap->the_hole_value());
     } else {
-      FixedDoubleArray* elms = FixedDoubleArray::cast(elms_obj);
-      MoveDoubleElements(elms, 0, elms, 1, len - 1);
+      Handle<FixedDoubleArray> elms = Handle<FixedDoubleArray>::cast(elms_obj);
+      MoveDoubleElements(*elms, 0, *elms, 1, len - 1);
       elms->set_the_hole(len - 1);
     }
   }
@@ -621,7 +620,7 @@ BUILTIN(ArrayShift) {
   // Set the length.
   array->set_length(Smi::FromInt(len - 1));
 
-  return first;
+  return *first;
 }
 
 
diff --git a/src/elements.cc b/src/elements.cc
index 5833e4c..5d3ef13 100644
--- a/src/elements.cc
+++ b/src/elements.cc
@@ -639,6 +639,19 @@ class ElementsAccessorBase : public ElementsAccessor {
         receiver, holder, key, backing_store);
   }
 
+  // TODO(ishell): Temporary wrapper until handlified.
+  MUST_USE_RESULT virtual Handle<Object> Get(
+      Handle<Object> receiver,
+      Handle<JSObject> holder,
+      uint32_t key,
+      Handle<FixedArrayBase> backing_store) {
+    CALL_HEAP_FUNCTION(holder->GetIsolate(),
+                       Get(*receiver, *holder, key,
+                           backing_store.is_null()
+                           ? NULL : *backing_store),
+                       Object);
+  }
+
   MUST_USE_RESULT virtual MaybeObject* Get(Object* receiver,
                                            JSObject* holder,
                                            uint32_t key,
diff --git a/src/elements.h b/src/elements.h
index d9376b2..bd5e722 100644
--- a/src/elements.h
+++ b/src/elements.h
@@ -65,6 +65,13 @@ class ElementsAccessor {
   // can optionally pass in the backing store to use for the check, which must
   // be compatible with the ElementsKind of the ElementsAccessor. If
   // backing_store is NULL, the holder->elements() is used as the backing store.
+  MUST_USE_RESULT virtual Handle<Object> Get(
+      Handle<Object> receiver,
+      Handle<JSObject> holder,
+      uint32_t key,
+      Handle<FixedArrayBase> backing_store =
+          Handle<FixedArrayBase>::null()) = 0;
+
   MUST_USE_RESULT virtual MaybeObject* Get(
       Object* receiver,
       JSObject* holder,
-- 
2.7.4