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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef vm_ArrayObject_inl_h
#define vm_ArrayObject_inl_h
#include "vm/ArrayObject.h"
#include "gc/GCTrace.h"
#include "vm/String.h"
#include "jsgcinlines.h"
#include "jsobjinlines.h"
#include "vm/TypeInference-inl.h"
namespace js {
inline void
ArrayObject::setLength(ExclusiveContext* cx, uint32_t length)
{
MOZ_ASSERT(lengthIsWritable());
MOZ_ASSERT_IF(length != getElementsHeader()->length, !denseElementsAreFrozen());
if (length > INT32_MAX) {
/* Track objects with overflowing lengths in type information. */
MarkObjectGroupFlags(cx, this, OBJECT_FLAG_LENGTH_OVERFLOW);
}
getElementsHeader()->length = length;
}
/* static */ inline ArrayObject*
ArrayObject::createArrayInternal(ExclusiveContext* cx, gc::AllocKind kind, gc::InitialHeap heap,
HandleShape shape, HandleObjectGroup group,
AutoSetNewObjectMetadata&)
{
// Create a new array and initialize everything except for its elements.
MOZ_ASSERT(shape && group);
MOZ_ASSERT(group->clasp() == shape->getObjectClass());
MOZ_ASSERT(group->clasp() == &ArrayObject::class_);
MOZ_ASSERT_IF(group->clasp()->hasFinalize(), heap == gc::TenuredHeap);
MOZ_ASSERT_IF(group->hasUnanalyzedPreliminaryObjects(),
heap == js::gc::TenuredHeap);
MOZ_ASSERT(group->clasp()->shouldDelayMetadataBuilder());
// Arrays can use their fixed slots to store elements, so can't have shapes
// which allow named properties to be stored in the fixed slots.
MOZ_ASSERT(shape->numFixedSlots() == 0);
size_t nDynamicSlots = dynamicSlotsCount(0, shape->slotSpan(), group->clasp());
JSObject* obj = Allocate<JSObject>(cx, kind, nDynamicSlots, heap, group->clasp());
if (!obj)
return nullptr;
static_cast<ArrayObject*>(obj)->shape_.init(shape);
static_cast<ArrayObject*>(obj)->group_.init(group);
cx->compartment()->setObjectPendingMetadata(cx, obj);
return &obj->as<ArrayObject>();
}
/* static */ inline ArrayObject*
ArrayObject::finishCreateArray(ArrayObject* obj, HandleShape shape, AutoSetNewObjectMetadata& metadata)
{
size_t span = shape->slotSpan();
if (span)
obj->initializeSlotRange(0, span);
gc::TraceCreateObject(obj);
return obj;
}
/* static */ inline ArrayObject*
ArrayObject::createArray(ExclusiveContext* cx, gc::AllocKind kind, gc::InitialHeap heap,
HandleShape shape, HandleObjectGroup group,
uint32_t length, AutoSetNewObjectMetadata& metadata)
{
ArrayObject* obj = createArrayInternal(cx, kind, heap, shape, group, metadata);
if (!obj)
return nullptr;
uint32_t capacity = gc::GetGCKindSlots(kind) - ObjectElements::VALUES_PER_HEADER;
obj->setFixedElements();
new (obj->getElementsHeader()) ObjectElements(capacity, length);
return finishCreateArray(obj, shape, metadata);
}
/* static */ inline ArrayObject*
ArrayObject::createCopyOnWriteArray(ExclusiveContext* cx, gc::InitialHeap heap,
HandleArrayObject sharedElementsOwner)
{
MOZ_ASSERT(sharedElementsOwner->getElementsHeader()->isCopyOnWrite());
MOZ_ASSERT(sharedElementsOwner->getElementsHeader()->ownerObject() == sharedElementsOwner);
// Use the smallest allocation kind for the array, as it can't have any
// fixed slots (see the assert in createArrayInternal) and will not be using
// its fixed elements.
gc::AllocKind kind = gc::AllocKind::OBJECT0_BACKGROUND;
AutoSetNewObjectMetadata metadata(cx);
RootedShape shape(cx, sharedElementsOwner->lastProperty());
RootedObjectGroup group(cx, sharedElementsOwner->group());
ArrayObject* obj = createArrayInternal(cx, kind, heap, shape, group, metadata);
if (!obj)
return nullptr;
obj->elements_ = sharedElementsOwner->getDenseElementsAllowCopyOnWrite();
return finishCreateArray(obj, shape, metadata);
}
} // namespace js
#endif // vm_ArrayObject_inl_h
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