/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- * vim: set ts=8 sts=2 et sw=2 tw=80: * 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_NativeObject_inl_h #define vm_NativeObject_inl_h #include "vm/NativeObject.h" #include "mozilla/Maybe.h" #include #include "gc/Allocator.h" #include "gc/GCProbes.h" #include "gc/MaybeRooted.h" #include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_* #include "vm/Compartment.h" #include "vm/Iteration.h" #include "vm/JSContext.h" #include "vm/PlainObject.h" #include "vm/PropertyResult.h" #include "vm/TypedArrayObject.h" #include "gc/Heap-inl.h" #include "gc/Marking-inl.h" #include "gc/ObjectKind-inl.h" #include "vm/Compartment-inl.h" #include "vm/JSObject-inl.h" #include "vm/Realm-inl.h" #include "vm/Shape-inl.h" #ifdef ENABLE_RECORD_TUPLE // Defined in vm/RecordTupleShared.{h,cpp}. We cannot include that file // because it causes circular dependencies. extern bool js::IsExtendedPrimitive(const JSObject& obj); #endif namespace js { inline uint32_t NativeObject::numFixedSlotsMaybeForwarded() const { return gc::MaybeForwarded(JSObject::shape())->asNative().numFixedSlots(); } inline uint8_t* NativeObject::fixedData(size_t nslots) const { MOZ_ASSERT(ClassCanHaveFixedData(gc::MaybeForwardedObjectClass(this))); MOZ_ASSERT(nslots == numFixedSlotsMaybeForwarded()); return reinterpret_cast(&fixedSlots()[nslots]); } inline void NativeObject::initDenseElementHole(uint32_t index) { markDenseElementsNotPacked(); initDenseElementUnchecked(index, MagicValue(JS_ELEMENTS_HOLE)); } inline void NativeObject::setDenseElementHole(uint32_t index) { markDenseElementsNotPacked(); setDenseElementUnchecked(index, MagicValue(JS_ELEMENTS_HOLE)); } inline void NativeObject::removeDenseElementForSparseIndex(uint32_t index) { MOZ_ASSERT(containsPure(PropertyKey::Int(index))); if (containsDenseElement(index)) { setDenseElementHole(index); } } inline void NativeObject::markDenseElementsNotPacked() { MOZ_ASSERT(is()); getElementsHeader()->markNonPacked(); } inline void NativeObject::elementsRangePostWriteBarrier(uint32_t start, uint32_t count) { if (!isTenured()) { return; } for (size_t i = 0; i < count; i++) { const Value& v = elements_[start + i]; if (v.isGCThing()) { if (gc::StoreBuffer* sb = v.toGCThing()->storeBuffer()) { sb->putSlot(this, HeapSlot::Element, unshiftedIndex(start + i), count - i); return; } } } } inline void NativeObject::copyDenseElements(uint32_t dstStart, const Value* src, uint32_t count) { MOZ_ASSERT(dstStart + count <= getDenseCapacity()); MOZ_ASSERT(isExtensible()); MOZ_ASSERT_IF(count > 0, src != nullptr); #ifdef DEBUG for (uint32_t i = 0; i < count; ++i) { checkStoredValue(src[i]); } #endif if (count == 0) { return; } if (zone()->needsIncrementalBarrier()) { uint32_t numShifted = getElementsHeader()->numShiftedElements(); for (uint32_t i = 0; i < count; ++i) { elements_[dstStart + i].set(this, HeapSlot::Element, dstStart + i + numShifted, src[i]); } } else { memcpy(reinterpret_cast(&elements_[dstStart]), src, count * sizeof(Value)); elementsRangePostWriteBarrier(dstStart, count); } } inline void NativeObject::initDenseElements(NativeObject* src, uint32_t srcStart, uint32_t count) { MOZ_ASSERT(src->getDenseInitializedLength() >= srcStart + count); const Value* vp = src->getDenseElements() + srcStart; if (!src->denseElementsArePacked()) { // Mark non-packed if we're copying holes or if there are too many elements // to check this efficiently. static constexpr uint32_t MaxCountForPackedCheck = 30; if (count > MaxCountForPackedCheck) { markDenseElementsNotPacked(); } else { for (uint32_t i = 0; i < count; i++) { if (vp[i].isMagic(JS_ELEMENTS_HOLE)) { markDenseElementsNotPacked(); break; } } } } initDenseElements(vp, count); } inline void NativeObject::initDenseElements(const Value* src, uint32_t count) { MOZ_ASSERT(getDenseInitializedLength() == 0); MOZ_ASSERT(count <= getDenseCapacity()); MOZ_ASSERT(src); MOZ_ASSERT(isExtensible()); setDenseInitializedLength(count); #ifdef DEBUG for (uint32_t i = 0; i < count; ++i) { checkStoredValue(src[i]); } #endif memcpy(reinterpret_cast(elements_), src, count * sizeof(Value)); elementsRangePostWriteBarrier(0, count); } template inline bool NativeObject::initDenseElementsFromRange(JSContext* cx, Iter begin, Iter end) { // This method populates the elements of a particular Array that's an // internal implementation detail of GeneratorObject. Failing any of the // following means the Array has escaped and/or been mistreated. MOZ_ASSERT(isExtensible()); MOZ_ASSERT(!isIndexed()); MOZ_ASSERT(is()); MOZ_ASSERT(as().lengthIsWritable()); MOZ_ASSERT(!denseElementsAreFrozen()); MOZ_ASSERT(getElementsHeader()->numShiftedElements() == 0); MOZ_ASSERT(getDenseInitializedLength() == 0); auto size = end - begin; uint32_t count = uint32_t(size); MOZ_ASSERT(count <= uint32_t(INT32_MAX)); if (count > getDenseCapacity()) { if (!growElements(cx, count)) { return false; } } HeapSlot* sp = elements_; size_t slot = 0; for (; begin != end; sp++, begin++) { Value v = *begin; #ifdef DEBUG checkStoredValue(v); #endif sp->init(this, HeapSlot::Element, slot++, v); } MOZ_ASSERT(slot == count); getElementsHeader()->initializedLength = count; as().setLength(count); return true; } inline bool NativeObject::tryShiftDenseElements(uint32_t count) { MOZ_ASSERT(isExtensible()); ObjectElements* header = getElementsHeader(); if (header->initializedLength == count || count > ObjectElements::MaxShiftedElements || header->hasNonwritableArrayLength()) { return false; } shiftDenseElementsUnchecked(count); return true; } inline void NativeObject::shiftDenseElementsUnchecked(uint32_t count) { MOZ_ASSERT(isExtensible()); ObjectElements* header = getElementsHeader(); MOZ_ASSERT(count > 0); MOZ_ASSERT(count < header->initializedLength); if (MOZ_UNLIKELY(header->numShiftedElements() + count > ObjectElements::MaxShiftedElements)) { moveShiftedElements(); header = getElementsHeader(); } prepareElementRangeForOverwrite(0, count); header->addShiftedElements(count); elements_ += count; ObjectElements* newHeader = getElementsHeader(); memmove(newHeader, header, sizeof(ObjectElements)); } inline void NativeObject::moveDenseElements(uint32_t dstStart, uint32_t srcStart, uint32_t count) { MOZ_ASSERT(dstStart + count <= getDenseCapacity()); MOZ_ASSERT(srcStart + count <= getDenseInitializedLength()); MOZ_ASSERT(isExtensible()); /* * Using memmove here would skip write barriers. Also, we need to consider * an array containing [A, B, C], in the following situation: * * 1. Incremental GC marks slot 0 of array (i.e., A), then returns to JS code. * 2. JS code moves slots 1..2 into slots 0..1, so it contains [B, C, C]. * 3. Incremental GC finishes by marking slots 1 and 2 (i.e., C). * * Since normal marking never happens on B, it is very important that the * write barrier is invoked here on B, despite the fact that it exists in * the array before and after the move. */ if (zone()->needsIncrementalBarrier()) { uint32_t numShifted = getElementsHeader()->numShiftedElements(); if (dstStart < srcStart) { HeapSlot* dst = elements_ + dstStart; HeapSlot* src = elements_ + srcStart; for (uint32_t i = 0; i < count; i++, dst++, src++) { dst->set(this, HeapSlot::Element, dst - elements_ + numShifted, *src); } } else { HeapSlot* dst = elements_ + dstStart + count - 1; HeapSlot* src = elements_ + srcStart + count - 1; for (uint32_t i = 0; i < count; i++, dst--, src--) { dst->set(this, HeapSlot::Element, dst - elements_ + numShifted, *src); } } } else { memmove(elements_ + dstStart, elements_ + srcStart, count * sizeof(HeapSlot)); elementsRangePostWriteBarrier(dstStart, count); } } inline void NativeObject::reverseDenseElementsNoPreBarrier(uint32_t length) { MOZ_ASSERT(!zone()->needsIncrementalBarrier()); MOZ_ASSERT(isExtensible()); MOZ_ASSERT(length > 1); MOZ_ASSERT(length <= getDenseInitializedLength()); Value* valLo = reinterpret_cast(elements_); Value* valHi = valLo + (length - 1); MOZ_ASSERT(valLo < valHi); do { Value origLo = *valLo; *valLo = *valHi; *valHi = origLo; ++valLo; --valHi; } while (valLo < valHi); elementsRangePostWriteBarrier(0, length); } inline void NativeObject::ensureDenseInitializedLength(uint32_t index, uint32_t extra) { // Ensure that the array's contents have been initialized up to index, and // mark the elements through 'index + extra' as initialized in preparation // for a write. MOZ_ASSERT(!denseElementsAreFrozen()); MOZ_ASSERT(isExtensible() || (containsDenseElement(index) && extra == 1)); MOZ_ASSERT(index + extra <= getDenseCapacity()); uint32_t initlen = getDenseInitializedLength(); if (index + extra <= initlen) { return; } MOZ_ASSERT(isExtensible()); if (index > initlen) { markDenseElementsNotPacked(); } uint32_t numShifted = getElementsHeader()->numShiftedElements(); size_t offset = initlen; for (HeapSlot* sp = elements_ + initlen; sp != elements_ + (index + extra); sp++, offset++) { sp->init(this, HeapSlot::Element, offset + numShifted, MagicValue(JS_ELEMENTS_HOLE)); } getElementsHeader()->initializedLength = index + extra; } DenseElementResult NativeObject::extendDenseElements(JSContext* cx, uint32_t requiredCapacity, uint32_t extra) { MOZ_ASSERT(isExtensible()); /* * Don't grow elements for objects which already have sparse indexes. * This avoids needing to count non-hole elements in willBeSparseElements * every time a new index is added. */ if (isIndexed()) { return DenseElementResult::Incomplete; } /* * We use the extra argument also as a hint about number of non-hole * elements to be inserted. */ if (requiredCapacity > MIN_SPARSE_INDEX && willBeSparseElements(requiredCapacity, extra)) { return DenseElementResult::Incomplete; } if (!growElements(cx, requiredCapacity)) { return DenseElementResult::Failure; } return DenseElementResult::Success; } inline DenseElementResult NativeObject::ensureDenseElements(JSContext* cx, uint32_t index, uint32_t extra) { MOZ_ASSERT(is()); MOZ_ASSERT(isExtensible() || (containsDenseElement(index) && extra == 1)); uint32_t requiredCapacity; if (extra == 1) { /* Optimize for the common case. */ if (index < getDenseCapacity()) { ensureDenseInitializedLength(index, 1); return DenseElementResult::Success; } requiredCapacity = index + 1; if (requiredCapacity == 0) { /* Overflow. */ return DenseElementResult::Incomplete; } } else { requiredCapacity = index + extra; if (requiredCapacity < index) { /* Overflow. */ return DenseElementResult::Incomplete; } if (requiredCapacity <= getDenseCapacity()) { ensureDenseInitializedLength(index, extra); return DenseElementResult::Success; } } DenseElementResult result = extendDenseElements(cx, requiredCapacity, extra); if (result != DenseElementResult::Success) { return result; } ensureDenseInitializedLength(index, extra); return DenseElementResult::Success; } inline DenseElementResult NativeObject::setOrExtendDenseElements( JSContext* cx, uint32_t start, const Value* vp, uint32_t count) { if (!isExtensible()) { return DenseElementResult::Incomplete; } if (is() && !as().lengthIsWritable() && start + count >= as().length()) { return DenseElementResult::Incomplete; } DenseElementResult result = ensureDenseElements(cx, start, count); if (result != DenseElementResult::Success) { return result; } if (is() && start + count >= as().length()) { as().setLength(start + count); } copyDenseElements(start, vp, count); return DenseElementResult::Success; } inline bool NativeObject::isInWholeCellBuffer() const { const gc::TenuredCell* cell = &asTenured(); gc::ArenaCellSet* cells = cell->arena()->bufferedCells(); return cells && cells->hasCell(cell); } /* static */ inline NativeObject* NativeObject::create( JSContext* cx, js::gc::AllocKind kind, js::gc::InitialHeap heap, js::Handle shape, js::gc::AllocSite* site /* = nullptr */) { debugCheckNewObject(shape, kind, heap); const JSClass* clasp = shape->getObjectClass(); MOZ_ASSERT(clasp->isNativeObject()); MOZ_ASSERT(!clasp->isJSFunction(), "should use JSFunction::create"); MOZ_ASSERT(clasp != &ArrayObject::class_, "should use ArrayObject::create"); const uint32_t nfixed = shape->numFixedSlots(); const uint32_t slotSpan = shape->slotSpan(); const size_t nDynamicSlots = calculateDynamicSlots(nfixed, slotSpan, clasp); NativeObject* nobj = cx->newCell(kind, nDynamicSlots, heap, clasp, site); if (!nobj) { return nullptr; } nobj->initShape(shape); // NOTE: Dynamic slots are created internally by Allocate. if (!nDynamicSlots) { nobj->initEmptyDynamicSlots(); } nobj->setEmptyElements(); if (slotSpan > 0) { nobj->initSlots(nfixed, slotSpan); } if (clasp->shouldDelayMetadataBuilder()) { cx->realm()->setObjectPendingMetadata(cx, nobj); } else { nobj = SetNewObjectMetadata(cx, nobj); } js::gc::gcprobes::CreateObject(nobj); return nobj; } MOZ_ALWAYS_INLINE void NativeObject::initEmptyDynamicSlots() { setEmptyDynamicSlots(0); } MOZ_ALWAYS_INLINE void NativeObject::setDictionaryModeSlotSpan(uint32_t span) { MOZ_ASSERT(inDictionaryMode()); if (!hasDynamicSlots()) { setEmptyDynamicSlots(span); return; } getSlotsHeader()->setDictionarySlotSpan(span); } MOZ_ALWAYS_INLINE void NativeObject::setEmptyDynamicSlots( uint32_t dictionarySlotSpan) { MOZ_ASSERT_IF(!inDictionaryMode(), dictionarySlotSpan == 0); MOZ_ASSERT(dictionarySlotSpan <= MAX_FIXED_SLOTS); slots_ = emptyObjectSlotsForDictionaryObject[dictionarySlotSpan]; MOZ_ASSERT(getSlotsHeader()->capacity() == 0); MOZ_ASSERT(getSlotsHeader()->dictionarySlotSpan() == dictionarySlotSpan); } MOZ_ALWAYS_INLINE bool NativeObject::setShapeAndAddNewSlots( JSContext* cx, SharedShape* newShape, uint32_t oldSpan, uint32_t newSpan) { MOZ_ASSERT(!inDictionaryMode()); MOZ_ASSERT(newShape->isShared()); MOZ_ASSERT(newShape->zone() == zone()); MOZ_ASSERT(newShape->numFixedSlots() == numFixedSlots()); MOZ_ASSERT(newShape->getObjectClass() == getClass()); MOZ_ASSERT(oldSpan < newSpan); MOZ_ASSERT(sharedShape()->slotSpan() == oldSpan); MOZ_ASSERT(newShape->slotSpan() == newSpan); uint32_t numFixed = newShape->numFixedSlots(); if (newSpan > numFixed) { uint32_t oldCapacity = numDynamicSlots(); uint32_t newCapacity = calculateDynamicSlots(numFixed, newSpan, newShape->getObjectClass()); MOZ_ASSERT(oldCapacity <= newCapacity); if (oldCapacity < newCapacity) { if (MOZ_UNLIKELY(!growSlots(cx, oldCapacity, newCapacity))) { return false; } } } // Initialize slots [oldSpan, newSpan). Use the *Unchecked version because // the shape's slot span does not reflect the allocated slots at this // point. auto initRange = [](HeapSlot* start, HeapSlot* end) { for (HeapSlot* slot = start; slot < end; slot++) { slot->initAsUndefined(); } }; forEachSlotRangeUnchecked(oldSpan, newSpan, initRange); setShape(newShape); return true; } MOZ_ALWAYS_INLINE bool NativeObject::setShapeAndAddNewSlot( JSContext* cx, SharedShape* newShape, uint32_t slot) { MOZ_ASSERT(!inDictionaryMode()); MOZ_ASSERT(newShape->isShared()); MOZ_ASSERT(newShape->zone() == zone()); MOZ_ASSERT(newShape->numFixedSlots() == numFixedSlots()); MOZ_ASSERT(newShape->base() == shape()->base()); MOZ_ASSERT(newShape->slotSpan() == sharedShape()->slotSpan() + 1); MOZ_ASSERT(newShape->slotSpan() == slot + 1); uint32_t numFixed = newShape->numFixedSlots(); if (slot < numFixed) { initFixedSlot(slot, UndefinedValue()); } else { uint32_t dynamicSlotIndex = slot - numFixed; if (dynamicSlotIndex >= numDynamicSlots()) { if (MOZ_UNLIKELY(!growSlotsForNewSlot(cx, numFixed, slot))) { return false; } } initDynamicSlot(numFixed, slot, UndefinedValue()); } setShape(newShape); return true; } inline js::gc::AllocKind NativeObject::allocKindForTenure() const { using namespace js::gc; AllocKind kind = GetGCObjectFixedSlotsKind(numFixedSlots()); MOZ_ASSERT(!IsBackgroundFinalized(kind)); if (!CanChangeToBackgroundAllocKind(kind, getClass())) { return kind; } return ForegroundToBackgroundAllocKind(kind); } inline js::GlobalObject& NativeObject::global() const { return nonCCWGlobal(); } inline bool NativeObject::denseElementsHaveMaybeInIterationFlag() { if (!getElementsHeader()->maybeInIteration()) { AssertDenseElementsNotIterated(this); return false; } return true; } inline bool NativeObject::denseElementsMaybeInIteration() { if (!denseElementsHaveMaybeInIterationFlag()) { return false; } return compartment()->objectMaybeInIteration(this); } /* * Call obj's resolve hook. * * cx and id are the parameters initially passed to the ongoing lookup; * propp and recursedp are its out parameters. * * There are four possible outcomes: * * - On failure, report an error or exception and return false. * * - If we are already resolving a property of obj, call setRecursiveResolve on * propp and return true. * * - If the resolve hook finds or defines the sought property, set propp * appropriately, and return true. * * - Otherwise no property was resolved. Set propp to NotFound and return true. */ static MOZ_ALWAYS_INLINE bool CallResolveOp(JSContext* cx, Handle obj, HandleId id, PropertyResult* propp) { MOZ_ASSERT(!cx->isHelperThreadContext()); // Avoid recursion on (obj, id) already being resolved on cx. AutoResolving resolving(cx, obj, id); if (resolving.alreadyStarted()) { // Already resolving id in obj, suppress recursion. propp->setRecursiveResolve(); return true; } bool resolved = false; AutoRealm ar(cx, obj); if (!obj->getClass()->getResolve()(cx, obj, id, &resolved)) { return false; } if (!resolved) { propp->setNotFound(); return true; } // Assert the mayResolve hook, if there is one, returns true for this // property. MOZ_ASSERT_IF(obj->getClass()->getMayResolve(), obj->getClass()->getMayResolve()(cx->names(), id, obj)); if (id.isInt()) { uint32_t index = id.toInt(); if (obj->containsDenseElement(index)) { propp->setDenseElement(index); return true; } } MOZ_ASSERT(!obj->is()); mozilla::Maybe prop = obj->lookup(cx, id); if (prop.isSome()) { propp->setNativeProperty(*prop); } else { propp->setNotFound(); } return true; } enum class LookupResolveMode { IgnoreResolve, CheckResolve, CheckMayResolve, }; template static MOZ_ALWAYS_INLINE bool NativeLookupOwnPropertyInline( JSContext* cx, typename MaybeRooted::HandleType obj, typename MaybeRooted::HandleType id, PropertyResult* propp) { // Native objects should should avoid `lookupProperty` hooks, and those that // use them should avoid recursively triggering lookup, and those that still // violate this guidance are the ModuleEnvironmentObject. MOZ_ASSERT_IF(obj->getOpsLookupProperty(), obj->template is()); #ifdef ENABLE_RECORD_TUPLE MOZ_ASSERT(!js::IsExtendedPrimitive(*obj)); #endif // Check for a native dense element. if (id.isInt()) { uint32_t index = id.toInt(); if (obj->containsDenseElement(index)) { propp->setDenseElement(index); return true; } } // Check for a typed array element. Integer lookups always finish here // so that integer properties on the prototype are ignored even for out // of bounds accesses. if (obj->template is()) { if (mozilla::Maybe index = ToTypedArrayIndex(id)) { uint64_t idx = index.value(); if (idx < obj->template as().length()) { propp->setTypedArrayElement(idx); } else { propp->setTypedArrayOutOfRange(); } return true; } } MOZ_ASSERT(cx->compartment() == obj->compartment()); // Check for a native property. Call Shape::lookup directly (instead of // NativeObject::lookup) because it's inlined. uint32_t index; if (PropMap* map = obj->shape()->lookup(cx, id, &index)) { propp->setNativeProperty(map->getPropertyInfo(index)); return true; } // Some callers explicitily want us to ignore the resolve hook entirely. In // that case, we report the property as NotFound. if constexpr (resolveMode == LookupResolveMode::IgnoreResolve) { propp->setNotFound(); return true; } // JITs in particular use the `mayResolve` hook to determine a JSClass can // never resolve this property name (for all instances of the class). if constexpr (resolveMode == LookupResolveMode::CheckMayResolve) { static_assert(allowGC == false, "CheckMayResolve can only be used with NoGC"); MOZ_ASSERT(propp->isNotFound()); return !ClassMayResolveId(cx->names(), obj->getClass(), id, obj); } MOZ_ASSERT(resolveMode == LookupResolveMode::CheckResolve); // If there is no resolve hook, the property definitely does not exist. if (obj->getClass()->getResolve()) { if constexpr (!allowGC) { return false; } else { return CallResolveOp(cx, obj, id, propp); } } propp->setNotFound(); return true; } /* * Simplified version of NativeLookupOwnPropertyInline that doesn't call * resolve hooks. */ [[nodiscard]] static inline bool NativeLookupOwnPropertyNoResolve( JSContext* cx, NativeObject* obj, jsid id, PropertyResult* result) { return NativeLookupOwnPropertyInline( cx, obj, id, result); } template static MOZ_ALWAYS_INLINE bool NativeLookupPropertyInline( JSContext* cx, typename MaybeRooted::HandleType obj, typename MaybeRooted::HandleType id, typename MaybeRooted< std::conditional_t, allowGC>::MutableHandleType objp, PropertyResult* propp) { /* Search scopes starting with obj and following the prototype link. */ typename MaybeRooted::RootType current(cx, obj); while (true) { if (!NativeLookupOwnPropertyInline(cx, current, id, propp)) { return false; } if (propp->isFound()) { objp.set(current); return true; } if (propp->shouldIgnoreProtoChain()) { break; } JSObject* proto = current->staticPrototype(); if (!proto) { break; } // If a `lookupProperty` hook exists, recurse into LookupProperty, otherwise // we can simply loop within this call frame. if (proto->getOpsLookupProperty()) { if constexpr (allowGC) { MOZ_ASSERT(!cx->isHelperThreadContext()); RootedObject protoRoot(cx, proto); return LookupProperty(cx, protoRoot, id, objp, propp); } else { return false; } } current = &proto->as(); } MOZ_ASSERT(propp->isNotFound()); objp.set(nullptr); return true; } inline bool ThrowIfNotConstructing(JSContext* cx, const CallArgs& args, const char* builtinName) { if (args.isConstructing()) { return true; } JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BUILTIN_CTOR_NO_NEW, builtinName); return false; } inline bool IsPackedArray(JSObject* obj) { if (!obj->is()) { return false; } ArrayObject* arr = &obj->as(); if (arr->getDenseInitializedLength() != arr->length()) { return false; } if (!arr->denseElementsArePacked()) { return false; } #ifdef DEBUG // Assert correctness of the NON_PACKED flag by checking the first few // elements don't contain holes. uint32_t numToCheck = std::min(5, arr->getDenseInitializedLength()); for (uint32_t i = 0; i < numToCheck; i++) { MOZ_ASSERT(!arr->getDenseElement(i).isMagic(JS_ELEMENTS_HOLE)); } #endif return true; } // Like AddDataProperty but optimized for plain objects. Plain objects don't // have an addProperty hook. MOZ_ALWAYS_INLINE bool AddDataPropertyToPlainObject(JSContext* cx, Handle obj, HandleId id, HandleValue v) { MOZ_ASSERT(!id.isInt()); uint32_t slot; if (!NativeObject::addProperty(cx, obj, id, PropertyFlags::defaultDataPropFlags, &slot)) { return false; } obj->initSlot(slot, v); MOZ_ASSERT(!obj->getClass()->getAddProperty()); return true; } } // namespace js #endif /* vm_NativeObject_inl_h */