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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /js/src/vm/UnboxedObject.cpp
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'js/src/vm/UnboxedObject.cpp')
-rw-r--r--js/src/vm/UnboxedObject.cpp2152
1 files changed, 2152 insertions, 0 deletions
diff --git a/js/src/vm/UnboxedObject.cpp b/js/src/vm/UnboxedObject.cpp
new file mode 100644
index 000000000..3018ace67
--- /dev/null
+++ b/js/src/vm/UnboxedObject.cpp
@@ -0,0 +1,2152 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+#include "vm/UnboxedObject-inl.h"
+
+#include "jit/BaselineIC.h"
+#include "jit/ExecutableAllocator.h"
+#include "jit/JitCommon.h"
+#include "jit/Linker.h"
+
+#include "jsobjinlines.h"
+
+#include "gc/Nursery-inl.h"
+#include "jit/MacroAssembler-inl.h"
+#include "vm/Shape-inl.h"
+
+using mozilla::ArrayLength;
+using mozilla::DebugOnly;
+using mozilla::PodCopy;
+
+using namespace js;
+
+/////////////////////////////////////////////////////////////////////
+// UnboxedLayout
+/////////////////////////////////////////////////////////////////////
+
+void
+UnboxedLayout::trace(JSTracer* trc)
+{
+ for (size_t i = 0; i < properties_.length(); i++)
+ TraceManuallyBarrieredEdge(trc, &properties_[i].name, "unboxed_layout_name");
+
+ if (newScript())
+ newScript()->trace(trc);
+
+ TraceNullableEdge(trc, &nativeGroup_, "unboxed_layout_nativeGroup");
+ TraceNullableEdge(trc, &nativeShape_, "unboxed_layout_nativeShape");
+ TraceNullableEdge(trc, &allocationScript_, "unboxed_layout_allocationScript");
+ TraceNullableEdge(trc, &replacementGroup_, "unboxed_layout_replacementGroup");
+ TraceNullableEdge(trc, &constructorCode_, "unboxed_layout_constructorCode");
+}
+
+size_t
+UnboxedLayout::sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+ return mallocSizeOf(this)
+ + properties_.sizeOfExcludingThis(mallocSizeOf)
+ + (newScript() ? newScript()->sizeOfIncludingThis(mallocSizeOf) : 0)
+ + mallocSizeOf(traceList());
+}
+
+void
+UnboxedLayout::setNewScript(TypeNewScript* newScript, bool writeBarrier /* = true */)
+{
+ if (newScript_ && writeBarrier)
+ TypeNewScript::writeBarrierPre(newScript_);
+ newScript_ = newScript;
+}
+
+// Constructor code returns a 0x1 value to indicate the constructor code should
+// be cleared.
+static const uintptr_t CLEAR_CONSTRUCTOR_CODE_TOKEN = 0x1;
+
+/* static */ bool
+UnboxedLayout::makeConstructorCode(JSContext* cx, HandleObjectGroup group)
+{
+ gc::AutoSuppressGC suppress(cx);
+
+ using namespace jit;
+
+ if (!cx->compartment()->ensureJitCompartmentExists(cx))
+ return false;
+
+ UnboxedLayout& layout = group->unboxedLayout();
+ MOZ_ASSERT(!layout.constructorCode());
+
+ UnboxedPlainObject* templateObject = UnboxedPlainObject::create(cx, group, TenuredObject);
+ if (!templateObject)
+ return false;
+
+ JitContext jitContext(cx, nullptr);
+
+ MacroAssembler masm;
+
+ Register propertiesReg, newKindReg;
+#ifdef JS_CODEGEN_X86
+ propertiesReg = eax;
+ newKindReg = ecx;
+ masm.loadPtr(Address(masm.getStackPointer(), sizeof(void*)), propertiesReg);
+ masm.loadPtr(Address(masm.getStackPointer(), 2 * sizeof(void*)), newKindReg);
+#else
+ propertiesReg = IntArgReg0;
+ newKindReg = IntArgReg1;
+#endif
+
+#ifdef JS_CODEGEN_ARM64
+ // ARM64 communicates stack address via sp, but uses a pseudo-sp for addressing.
+ masm.initStackPtr();
+#endif
+
+ MOZ_ASSERT(propertiesReg.volatile_());
+ MOZ_ASSERT(newKindReg.volatile_());
+
+ AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+ regs.take(propertiesReg);
+ regs.take(newKindReg);
+ Register object = regs.takeAny(), scratch1 = regs.takeAny(), scratch2 = regs.takeAny();
+
+ LiveGeneralRegisterSet savedNonVolatileRegisters = SavedNonVolatileRegisters(regs);
+ masm.PushRegsInMask(savedNonVolatileRegisters);
+
+ // The scratch double register might be used by MacroAssembler methods.
+ if (ScratchDoubleReg.volatile_())
+ masm.push(ScratchDoubleReg);
+
+ Label failure, tenuredObject, allocated;
+ masm.branch32(Assembler::NotEqual, newKindReg, Imm32(GenericObject), &tenuredObject);
+ masm.branchTest32(Assembler::NonZero, AbsoluteAddress(group->addressOfFlags()),
+ Imm32(OBJECT_FLAG_PRE_TENURE), &tenuredObject);
+
+ // Allocate an object in the nursery
+ masm.createGCObject(object, scratch1, templateObject, gc::DefaultHeap, &failure,
+ /* initFixedSlots = */ false);
+
+ masm.jump(&allocated);
+ masm.bind(&tenuredObject);
+
+ // Allocate an object in the tenured heap.
+ masm.createGCObject(object, scratch1, templateObject, gc::TenuredHeap, &failure,
+ /* initFixedSlots = */ false);
+
+ // If any of the properties being stored are in the nursery, add a store
+ // buffer entry for the new object.
+ Label postBarrier;
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ if (property.type == JSVAL_TYPE_OBJECT) {
+ Address valueAddress(propertiesReg, i * sizeof(IdValuePair) + offsetof(IdValuePair, value));
+ Label notObject;
+ masm.branchTestObject(Assembler::NotEqual, valueAddress, &notObject);
+ Register valueObject = masm.extractObject(valueAddress, scratch1);
+ masm.branchPtrInNurseryChunk(Assembler::Equal, valueObject, scratch2, &postBarrier);
+ masm.bind(&notObject);
+ }
+ }
+
+ masm.jump(&allocated);
+ masm.bind(&postBarrier);
+
+ LiveGeneralRegisterSet liveVolatileRegisters;
+ liveVolatileRegisters.add(propertiesReg);
+ if (object.volatile_())
+ liveVolatileRegisters.add(object);
+ masm.PushRegsInMask(liveVolatileRegisters);
+
+ masm.mov(ImmPtr(cx->runtime()), scratch1);
+ masm.setupUnalignedABICall(scratch2);
+ masm.passABIArg(scratch1);
+ masm.passABIArg(object);
+ masm.callWithABI(JS_FUNC_TO_DATA_PTR(void*, PostWriteBarrier));
+
+ masm.PopRegsInMask(liveVolatileRegisters);
+
+ masm.bind(&allocated);
+
+ ValueOperand valueOperand;
+#ifdef JS_NUNBOX32
+ valueOperand = ValueOperand(scratch1, scratch2);
+#else
+ valueOperand = ValueOperand(scratch1);
+#endif
+
+ Label failureStoreOther, failureStoreObject;
+
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ Address valueAddress(propertiesReg, i * sizeof(IdValuePair) + offsetof(IdValuePair, value));
+ Address targetAddress(object, UnboxedPlainObject::offsetOfData() + property.offset);
+
+ masm.loadValue(valueAddress, valueOperand);
+
+ if (property.type == JSVAL_TYPE_OBJECT) {
+ HeapTypeSet* types = group->maybeGetProperty(IdToTypeId(NameToId(property.name)));
+
+ Label notObject;
+ masm.branchTestObject(Assembler::NotEqual, valueOperand,
+ types->mightBeMIRType(MIRType::Null) ? &notObject : &failureStoreObject);
+
+ Register payloadReg = masm.extractObject(valueOperand, scratch1);
+
+ if (!types->hasType(TypeSet::AnyObjectType())) {
+ Register scratch = (payloadReg == scratch1) ? scratch2 : scratch1;
+ masm.guardObjectType(payloadReg, types, scratch, &failureStoreObject);
+ }
+
+ masm.storeUnboxedProperty(targetAddress, JSVAL_TYPE_OBJECT,
+ TypedOrValueRegister(MIRType::Object,
+ AnyRegister(payloadReg)), nullptr);
+
+ if (notObject.used()) {
+ Label done;
+ masm.jump(&done);
+ masm.bind(&notObject);
+ masm.branchTestNull(Assembler::NotEqual, valueOperand, &failureStoreOther);
+ masm.storeUnboxedProperty(targetAddress, JSVAL_TYPE_OBJECT, NullValue(), nullptr);
+ masm.bind(&done);
+ }
+ } else {
+ masm.storeUnboxedProperty(targetAddress, property.type,
+ ConstantOrRegister(valueOperand), &failureStoreOther);
+ }
+ }
+
+ Label done;
+ masm.bind(&done);
+
+ if (object != ReturnReg)
+ masm.movePtr(object, ReturnReg);
+
+ // Restore non-volatile registers which were saved on entry.
+ if (ScratchDoubleReg.volatile_())
+ masm.pop(ScratchDoubleReg);
+ masm.PopRegsInMask(savedNonVolatileRegisters);
+
+ masm.abiret();
+
+ masm.bind(&failureStoreOther);
+
+ // There was a failure while storing a value which cannot be stored at all
+ // in the unboxed object. Initialize the object so it is safe for GC and
+ // return null.
+ masm.initUnboxedObjectContents(object, templateObject);
+
+ masm.bind(&failure);
+
+ masm.movePtr(ImmWord(0), object);
+ masm.jump(&done);
+
+ masm.bind(&failureStoreObject);
+
+ // There was a failure while storing a value to an object slot of the
+ // unboxed object. If the value is storable, the failure occurred due to
+ // incomplete type information in the object, so return a token to trigger
+ // regeneration of the jitcode after a new object is created in the VM.
+ {
+ Label isObject;
+ masm.branchTestObject(Assembler::Equal, valueOperand, &isObject);
+ masm.branchTestNull(Assembler::NotEqual, valueOperand, &failureStoreOther);
+ masm.bind(&isObject);
+ }
+
+ // Initialize the object so it is safe for GC.
+ masm.initUnboxedObjectContents(object, templateObject);
+
+ masm.movePtr(ImmWord(CLEAR_CONSTRUCTOR_CODE_TOKEN), object);
+ masm.jump(&done);
+
+ Linker linker(masm);
+ AutoFlushICache afc("UnboxedObject");
+ JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
+ if (!code)
+ return false;
+
+ layout.setConstructorCode(code);
+ return true;
+}
+
+void
+UnboxedLayout::detachFromCompartment()
+{
+ if (isInList())
+ remove();
+}
+
+/////////////////////////////////////////////////////////////////////
+// UnboxedPlainObject
+/////////////////////////////////////////////////////////////////////
+
+bool
+UnboxedPlainObject::setValue(ExclusiveContext* cx, const UnboxedLayout::Property& property,
+ const Value& v)
+{
+ uint8_t* p = &data_[property.offset];
+ return SetUnboxedValue(cx, this, NameToId(property.name), p, property.type, v,
+ /* preBarrier = */ true);
+}
+
+Value
+UnboxedPlainObject::getValue(const UnboxedLayout::Property& property,
+ bool maybeUninitialized /* = false */)
+{
+ uint8_t* p = &data_[property.offset];
+ return GetUnboxedValue(p, property.type, maybeUninitialized);
+}
+
+void
+UnboxedPlainObject::trace(JSTracer* trc, JSObject* obj)
+{
+ if (obj->as<UnboxedPlainObject>().expando_) {
+ TraceManuallyBarrieredEdge(trc,
+ reinterpret_cast<NativeObject**>(&obj->as<UnboxedPlainObject>().expando_),
+ "unboxed_expando");
+ }
+
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layoutDontCheckGeneration();
+ const int32_t* list = layout.traceList();
+ if (!list)
+ return;
+
+ uint8_t* data = obj->as<UnboxedPlainObject>().data();
+ while (*list != -1) {
+ GCPtrString* heap = reinterpret_cast<GCPtrString*>(data + *list);
+ TraceEdge(trc, heap, "unboxed_string");
+ list++;
+ }
+ list++;
+ while (*list != -1) {
+ GCPtrObject* heap = reinterpret_cast<GCPtrObject*>(data + *list);
+ TraceNullableEdge(trc, heap, "unboxed_object");
+ list++;
+ }
+
+ // Unboxed objects don't have Values to trace.
+ MOZ_ASSERT(*(list + 1) == -1);
+}
+
+/* static */ UnboxedExpandoObject*
+UnboxedPlainObject::ensureExpando(JSContext* cx, Handle<UnboxedPlainObject*> obj)
+{
+ if (obj->expando_)
+ return obj->expando_;
+
+ UnboxedExpandoObject* expando =
+ NewObjectWithGivenProto<UnboxedExpandoObject>(cx, nullptr, gc::AllocKind::OBJECT4);
+ if (!expando)
+ return nullptr;
+
+ // Don't track property types for expando objects. This allows Baseline
+ // and Ion AddSlot ICs to guard on the unboxed group without guarding on
+ // the expando group.
+ MarkObjectGroupUnknownProperties(cx, expando->group());
+
+ // If the expando is tenured then the original object must also be tenured.
+ // Otherwise barriers triggered on the original object for writes to the
+ // expando (as can happen in the JIT) won't see the tenured->nursery edge.
+ // See WholeCellEdges::mark.
+ MOZ_ASSERT_IF(!IsInsideNursery(expando), !IsInsideNursery(obj));
+
+ // As with setValue(), we need to manually trigger post barriers on the
+ // whole object. If we treat the field as a GCPtrObject and later
+ // convert the object to its native representation, we will end up with a
+ // corrupted store buffer entry.
+ if (IsInsideNursery(expando) && !IsInsideNursery(obj))
+ cx->runtime()->gc.storeBuffer.putWholeCell(obj);
+
+ obj->expando_ = expando;
+ return expando;
+}
+
+bool
+UnboxedPlainObject::containsUnboxedOrExpandoProperty(ExclusiveContext* cx, jsid id) const
+{
+ if (layout().lookup(id))
+ return true;
+
+ if (maybeExpando() && maybeExpando()->containsShapeOrElement(cx, id))
+ return true;
+
+ return false;
+}
+
+static bool
+PropagatePropertyTypes(JSContext* cx, jsid id, ObjectGroup* oldGroup, ObjectGroup* newGroup)
+{
+ HeapTypeSet* typeProperty = oldGroup->maybeGetProperty(id);
+ TypeSet::TypeList types;
+ if (!typeProperty->enumerateTypes(&types)) {
+ ReportOutOfMemory(cx);
+ return false;
+ }
+ for (size_t j = 0; j < types.length(); j++)
+ AddTypePropertyId(cx, newGroup, nullptr, id, types[j]);
+ return true;
+}
+
+static PlainObject*
+MakeReplacementTemplateObject(JSContext* cx, HandleObjectGroup group, const UnboxedLayout &layout)
+{
+ PlainObject* obj = NewObjectWithGroup<PlainObject>(cx, group, layout.getAllocKind(),
+ TenuredObject);
+ if (!obj)
+ return nullptr;
+
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ if (!obj->addDataProperty(cx, NameToId(property.name), i, JSPROP_ENUMERATE))
+ return nullptr;
+ MOZ_ASSERT(obj->slotSpan() == i + 1);
+ MOZ_ASSERT(!obj->inDictionaryMode());
+ }
+
+ return obj;
+}
+
+/* static */ bool
+UnboxedLayout::makeNativeGroup(JSContext* cx, ObjectGroup* group)
+{
+ AutoEnterAnalysis enter(cx);
+
+ UnboxedLayout& layout = group->unboxedLayout();
+ Rooted<TaggedProto> proto(cx, group->proto());
+
+ MOZ_ASSERT(!layout.nativeGroup());
+
+ RootedObjectGroup replacementGroup(cx);
+
+ const Class* clasp = layout.isArray() ? &ArrayObject::class_ : &PlainObject::class_;
+
+ // Immediately clear any new script on the group. This is done by replacing
+ // the existing new script with one for a replacement default new group.
+ // This is done so that the size of the replacment group's objects is the
+ // same as that for the unboxed group, so that we do not see polymorphic
+ // slot accesses later on for sites that see converted objects from this
+ // group and objects that were allocated using the replacement new group.
+ if (layout.newScript()) {
+ MOZ_ASSERT(!layout.isArray());
+
+ replacementGroup = ObjectGroupCompartment::makeGroup(cx, &PlainObject::class_, proto);
+ if (!replacementGroup)
+ return false;
+
+ PlainObject* templateObject = MakeReplacementTemplateObject(cx, replacementGroup, layout);
+ if (!templateObject)
+ return false;
+
+ TypeNewScript* replacementNewScript =
+ TypeNewScript::makeNativeVersion(cx, layout.newScript(), templateObject);
+ if (!replacementNewScript)
+ return false;
+
+ replacementGroup->setNewScript(replacementNewScript);
+ gc::TraceTypeNewScript(replacementGroup);
+
+ group->clearNewScript(cx, replacementGroup);
+ }
+
+ // Similarly, if this group is keyed to an allocation site, replace its
+ // entry with a new group that has no unboxed layout.
+ if (layout.allocationScript()) {
+ RootedScript script(cx, layout.allocationScript());
+ jsbytecode* pc = layout.allocationPc();
+
+ replacementGroup = ObjectGroupCompartment::makeGroup(cx, clasp, proto);
+ if (!replacementGroup)
+ return false;
+
+ PlainObject* templateObject = &script->getObject(pc)->as<PlainObject>();
+ replacementGroup->addDefiniteProperties(cx, templateObject->lastProperty());
+
+ JSProtoKey key = layout.isArray() ? JSProto_Array : JSProto_Object;
+ cx->compartment()->objectGroups.replaceAllocationSiteGroup(script, pc, key,
+ replacementGroup);
+
+ // Clear any baseline information at this opcode which might use the old group.
+ if (script->hasBaselineScript()) {
+ jit::ICEntry& entry = script->baselineScript()->icEntryFromPCOffset(script->pcToOffset(pc));
+ jit::ICFallbackStub* fallback = entry.fallbackStub();
+ for (jit::ICStubIterator iter = fallback->beginChain(); !iter.atEnd(); iter++)
+ iter.unlink(cx);
+ if (fallback->isNewObject_Fallback())
+ fallback->toNewObject_Fallback()->setTemplateObject(nullptr);
+ else if (fallback->isNewArray_Fallback())
+ fallback->toNewArray_Fallback()->setTemplateGroup(replacementGroup);
+ }
+ }
+
+ size_t nfixed = layout.isArray() ? 0 : gc::GetGCKindSlots(layout.getAllocKind());
+
+ if (layout.isArray()) {
+ // The length shape to use for arrays is cached via a modified initial
+ // shape for array objects. Create an array now to make sure this entry
+ // is instantiated.
+ if (!NewDenseEmptyArray(cx))
+ return false;
+ }
+
+ RootedShape shape(cx, EmptyShape::getInitialShape(cx, clasp, proto, nfixed, 0));
+ if (!shape)
+ return false;
+
+ MOZ_ASSERT_IF(layout.isArray(), !shape->isEmptyShape() && shape->slotSpan() == 0);
+
+ // Add shapes for each property, if this is for a plain object.
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+
+ Rooted<StackShape> child(cx, StackShape(shape->base()->unowned(), NameToId(property.name),
+ i, JSPROP_ENUMERATE, 0));
+ shape = cx->zone()->propertyTree.getChild(cx, shape, child);
+ if (!shape)
+ return false;
+ }
+
+ ObjectGroup* nativeGroup =
+ ObjectGroupCompartment::makeGroup(cx, clasp, proto,
+ group->flags() & OBJECT_FLAG_DYNAMIC_MASK);
+ if (!nativeGroup)
+ return false;
+
+ // No sense propagating if we don't know what we started with.
+ if (!group->unknownProperties()) {
+ // Propagate all property types from the old group to the new group.
+ if (layout.isArray()) {
+ if (!PropagatePropertyTypes(cx, JSID_VOID, group, nativeGroup))
+ return false;
+ } else {
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ jsid id = NameToId(property.name);
+ if (!PropagatePropertyTypes(cx, id, group, nativeGroup))
+ return false;
+
+ // If we are OOM we may not be able to propagate properties.
+ if (nativeGroup->unknownProperties())
+ break;
+
+ HeapTypeSet* nativeProperty = nativeGroup->maybeGetProperty(id);
+ if (nativeProperty && nativeProperty->canSetDefinite(i))
+ nativeProperty->setDefinite(i);
+ }
+ }
+ } else {
+ // If we skip, though, the new group had better agree.
+ MOZ_ASSERT(nativeGroup->unknownProperties());
+ }
+
+ layout.nativeGroup_ = nativeGroup;
+ layout.nativeShape_ = shape;
+ layout.replacementGroup_ = replacementGroup;
+
+ nativeGroup->setOriginalUnboxedGroup(group);
+
+ group->markStateChange(cx);
+
+ return true;
+}
+
+/* static */ bool
+UnboxedPlainObject::convertToNative(JSContext* cx, JSObject* obj)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+ UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando();
+
+ if (!layout.nativeGroup()) {
+ if (!UnboxedLayout::makeNativeGroup(cx, obj->group()))
+ return false;
+
+ // makeNativeGroup can reentrantly invoke this method.
+ if (obj->is<PlainObject>())
+ return true;
+ }
+
+ AutoValueVector values(cx);
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ // We might be reading properties off the object which have not been
+ // initialized yet. Make sure any double values we read here are
+ // canonicalized.
+ if (!values.append(obj->as<UnboxedPlainObject>().getValue(layout.properties()[i], true)))
+ return false;
+ }
+
+ // We are eliminating the expando edge with the conversion, so trigger a
+ // pre barrier.
+ JSObject::writeBarrierPre(expando);
+
+ // Additionally trigger a post barrier on the expando itself. Whole cell
+ // store buffer entries can be added on the original unboxed object for
+ // writes to the expando (see WholeCellEdges::trace), so after conversion
+ // we need to make sure the expando itself will still be traced.
+ if (expando && !IsInsideNursery(expando))
+ cx->runtime()->gc.storeBuffer.putWholeCell(expando);
+
+ obj->setGroup(layout.nativeGroup());
+ obj->as<PlainObject>().setLastPropertyMakeNative(cx, layout.nativeShape());
+
+ for (size_t i = 0; i < values.length(); i++)
+ obj->as<PlainObject>().initSlotUnchecked(i, values[i]);
+
+ if (expando) {
+ // Add properties from the expando object to the object, in order.
+ // Suppress GC here, so that callers don't need to worry about this
+ // method collecting. The stuff below can only fail due to OOM, in
+ // which case the object will not have been completely filled back in.
+ gc::AutoSuppressGC suppress(cx);
+
+ Vector<jsid> ids(cx);
+ for (Shape::Range<NoGC> r(expando->lastProperty()); !r.empty(); r.popFront()) {
+ if (!ids.append(r.front().propid()))
+ return false;
+ }
+ for (size_t i = 0; i < expando->getDenseInitializedLength(); i++) {
+ if (!expando->getDenseElement(i).isMagic(JS_ELEMENTS_HOLE)) {
+ if (!ids.append(INT_TO_JSID(i)))
+ return false;
+ }
+ }
+ ::Reverse(ids.begin(), ids.end());
+
+ RootedPlainObject nobj(cx, &obj->as<PlainObject>());
+ Rooted<UnboxedExpandoObject*> nexpando(cx, expando);
+ RootedId id(cx);
+ Rooted<PropertyDescriptor> desc(cx);
+ for (size_t i = 0; i < ids.length(); i++) {
+ id = ids[i];
+ if (!GetOwnPropertyDescriptor(cx, nexpando, id, &desc))
+ return false;
+ ObjectOpResult result;
+ if (!DefineProperty(cx, nobj, id, desc, result))
+ return false;
+ MOZ_ASSERT(result.ok());
+ }
+ }
+
+ return true;
+}
+
+/* static */
+UnboxedPlainObject*
+UnboxedPlainObject::create(ExclusiveContext* cx, HandleObjectGroup group, NewObjectKind newKind)
+{
+ AutoSetNewObjectMetadata metadata(cx);
+
+ MOZ_ASSERT(group->clasp() == &class_);
+ gc::AllocKind allocKind = group->unboxedLayout().getAllocKind();
+
+ UnboxedPlainObject* res =
+ NewObjectWithGroup<UnboxedPlainObject>(cx, group, allocKind, newKind);
+ if (!res)
+ return nullptr;
+
+ // Overwrite the dummy shape which was written to the object's expando field.
+ res->initExpando();
+
+ // Initialize reference fields of the object. All fields in the object will
+ // be overwritten shortly, but references need to be safe for the GC.
+ const int32_t* list = res->layout().traceList();
+ if (list) {
+ uint8_t* data = res->data();
+ while (*list != -1) {
+ GCPtrString* heap = reinterpret_cast<GCPtrString*>(data + *list);
+ heap->init(cx->names().empty);
+ list++;
+ }
+ list++;
+ while (*list != -1) {
+ GCPtrObject* heap = reinterpret_cast<GCPtrObject*>(data + *list);
+ heap->init(nullptr);
+ list++;
+ }
+ // Unboxed objects don't have Values to initialize.
+ MOZ_ASSERT(*(list + 1) == -1);
+ }
+
+ return res;
+}
+
+/* static */ JSObject*
+UnboxedPlainObject::createWithProperties(ExclusiveContext* cx, HandleObjectGroup group,
+ NewObjectKind newKind, IdValuePair* properties)
+{
+ MOZ_ASSERT(newKind == GenericObject || newKind == TenuredObject);
+
+ UnboxedLayout& layout = group->unboxedLayout();
+
+ if (layout.constructorCode()) {
+ MOZ_ASSERT(cx->isJSContext());
+
+ typedef JSObject* (*ConstructorCodeSignature)(IdValuePair*, NewObjectKind);
+ ConstructorCodeSignature function =
+ reinterpret_cast<ConstructorCodeSignature>(layout.constructorCode()->raw());
+
+ JSObject* obj;
+ {
+ JS::AutoSuppressGCAnalysis nogc;
+ obj = reinterpret_cast<JSObject*>(CALL_GENERATED_2(function, properties, newKind));
+ }
+ if (obj > reinterpret_cast<JSObject*>(CLEAR_CONSTRUCTOR_CODE_TOKEN))
+ return obj;
+
+ if (obj == reinterpret_cast<JSObject*>(CLEAR_CONSTRUCTOR_CODE_TOKEN))
+ layout.setConstructorCode(nullptr);
+ }
+
+ UnboxedPlainObject* obj = UnboxedPlainObject::create(cx, group, newKind);
+ if (!obj)
+ return nullptr;
+
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ if (!obj->setValue(cx, layout.properties()[i], properties[i].value))
+ return NewPlainObjectWithProperties(cx, properties, layout.properties().length(), newKind);
+ }
+
+#ifndef JS_CODEGEN_NONE
+ if (cx->isJSContext() &&
+ !group->unknownProperties() &&
+ !layout.constructorCode() &&
+ cx->asJSContext()->runtime()->jitSupportsFloatingPoint &&
+ jit::CanLikelyAllocateMoreExecutableMemory())
+ {
+ if (!UnboxedLayout::makeConstructorCode(cx->asJSContext(), group))
+ return nullptr;
+ }
+#endif
+
+ return obj;
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_lookupProperty(JSContext* cx, HandleObject obj,
+ HandleId id, MutableHandleObject objp,
+ MutableHandleShape propp)
+{
+ if (obj->as<UnboxedPlainObject>().containsUnboxedOrExpandoProperty(cx, id)) {
+ MarkNonNativePropertyFound<CanGC>(propp);
+ objp.set(obj);
+ return true;
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ objp.set(nullptr);
+ propp.set(nullptr);
+ return true;
+ }
+
+ return LookupProperty(cx, proto, id, objp, propp);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_defineProperty(JSContext* cx, HandleObject obj, HandleId id,
+ Handle<PropertyDescriptor> desc,
+ ObjectOpResult& result)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ if (!desc.getter() && !desc.setter() && desc.attributes() == JSPROP_ENUMERATE) {
+ // This define is equivalent to setting an existing property.
+ if (obj->as<UnboxedPlainObject>().setValue(cx, *property, desc.value()))
+ return result.succeed();
+ }
+
+ // Trying to incompatibly redefine an existing property requires the
+ // object to be converted to a native object.
+ if (!convertToNative(cx, obj))
+ return false;
+
+ return DefineProperty(cx, obj, id, desc, result);
+ }
+
+ // Define the property on the expando object.
+ Rooted<UnboxedExpandoObject*> expando(cx, ensureExpando(cx, obj.as<UnboxedPlainObject>()));
+ if (!expando)
+ return false;
+
+ // Update property types on the unboxed object as well.
+ AddTypePropertyId(cx, obj, id, desc.value());
+
+ return DefineProperty(cx, expando, id, desc, result);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_hasProperty(JSContext* cx, HandleObject obj, HandleId id, bool* foundp)
+{
+ if (obj->as<UnboxedPlainObject>().containsUnboxedOrExpandoProperty(cx, id)) {
+ *foundp = true;
+ return true;
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ *foundp = false;
+ return true;
+ }
+
+ return HasProperty(cx, proto, id, foundp);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_getProperty(JSContext* cx, HandleObject obj, HandleValue receiver,
+ HandleId id, MutableHandleValue vp)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ vp.set(obj->as<UnboxedPlainObject>().getValue(*property));
+ return true;
+ }
+
+ if (UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando()) {
+ if (expando->containsShapeOrElement(cx, id)) {
+ RootedObject nexpando(cx, expando);
+ return GetProperty(cx, nexpando, receiver, id, vp);
+ }
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ vp.setUndefined();
+ return true;
+ }
+
+ return GetProperty(cx, proto, receiver, id, vp);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_setProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v,
+ HandleValue receiver, ObjectOpResult& result)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ if (receiver.isObject() && obj == &receiver.toObject()) {
+ if (obj->as<UnboxedPlainObject>().setValue(cx, *property, v))
+ return result.succeed();
+
+ if (!convertToNative(cx, obj))
+ return false;
+ return SetProperty(cx, obj, id, v, receiver, result);
+ }
+
+ return SetPropertyByDefining(cx, id, v, receiver, result);
+ }
+
+ if (UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando()) {
+ if (expando->containsShapeOrElement(cx, id)) {
+ // Update property types on the unboxed object as well.
+ AddTypePropertyId(cx, obj, id, v);
+
+ RootedObject nexpando(cx, expando);
+ return SetProperty(cx, nexpando, id, v, receiver, result);
+ }
+ }
+
+ return SetPropertyOnProto(cx, obj, id, v, receiver, result);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_getOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id,
+ MutableHandle<PropertyDescriptor> desc)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ desc.value().set(obj->as<UnboxedPlainObject>().getValue(*property));
+ desc.setAttributes(JSPROP_ENUMERATE);
+ desc.object().set(obj);
+ return true;
+ }
+
+ if (UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando()) {
+ if (expando->containsShapeOrElement(cx, id)) {
+ RootedObject nexpando(cx, expando);
+ if (!GetOwnPropertyDescriptor(cx, nexpando, id, desc))
+ return false;
+ if (desc.object() == nexpando)
+ desc.object().set(obj);
+ return true;
+ }
+ }
+
+ desc.object().set(nullptr);
+ return true;
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_deleteProperty(JSContext* cx, HandleObject obj, HandleId id,
+ ObjectOpResult& result)
+{
+ if (!convertToNative(cx, obj))
+ return false;
+ return DeleteProperty(cx, obj, id, result);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_watch(JSContext* cx, HandleObject obj, HandleId id, HandleObject callable)
+{
+ if (!convertToNative(cx, obj))
+ return false;
+ return WatchProperty(cx, obj, id, callable);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_enumerate(JSContext* cx, HandleObject obj, AutoIdVector& properties,
+ bool enumerableOnly)
+{
+ // Ignore expando properties here, they are special-cased by the property
+ // enumeration code.
+
+ const UnboxedLayout::PropertyVector& unboxed = obj->as<UnboxedPlainObject>().layout().properties();
+ for (size_t i = 0; i < unboxed.length(); i++) {
+ if (!properties.append(NameToId(unboxed[i].name)))
+ return false;
+ }
+
+ return true;
+}
+
+const Class UnboxedExpandoObject::class_ = {
+ "UnboxedExpandoObject",
+ 0
+};
+
+static const ClassOps UnboxedPlainObjectClassOps = {
+ nullptr, /* addProperty */
+ nullptr, /* delProperty */
+ nullptr, /* getProperty */
+ nullptr, /* setProperty */
+ nullptr, /* enumerate */
+ nullptr, /* resolve */
+ nullptr, /* mayResolve */
+ nullptr, /* finalize */
+ nullptr, /* call */
+ nullptr, /* hasInstance */
+ nullptr, /* construct */
+ UnboxedPlainObject::trace,
+};
+
+static const ObjectOps UnboxedPlainObjectObjectOps = {
+ UnboxedPlainObject::obj_lookupProperty,
+ UnboxedPlainObject::obj_defineProperty,
+ UnboxedPlainObject::obj_hasProperty,
+ UnboxedPlainObject::obj_getProperty,
+ UnboxedPlainObject::obj_setProperty,
+ UnboxedPlainObject::obj_getOwnPropertyDescriptor,
+ UnboxedPlainObject::obj_deleteProperty,
+ UnboxedPlainObject::obj_watch,
+ nullptr, /* No unwatch needed, as watch() converts the object to native */
+ nullptr, /* getElements */
+ UnboxedPlainObject::obj_enumerate,
+ nullptr /* funToString */
+};
+
+const Class UnboxedPlainObject::class_ = {
+ js_Object_str,
+ Class::NON_NATIVE |
+ JSCLASS_HAS_CACHED_PROTO(JSProto_Object) |
+ JSCLASS_DELAY_METADATA_BUILDER,
+ &UnboxedPlainObjectClassOps,
+ JS_NULL_CLASS_SPEC,
+ JS_NULL_CLASS_EXT,
+ &UnboxedPlainObjectObjectOps
+};
+
+/////////////////////////////////////////////////////////////////////
+// UnboxedArrayObject
+/////////////////////////////////////////////////////////////////////
+
+template <JSValueType Type>
+DenseElementResult
+AppendUnboxedDenseElements(UnboxedArrayObject* obj, uint32_t initlen,
+ MutableHandle<GCVector<Value>> values)
+{
+ for (size_t i = 0; i < initlen; i++)
+ values.infallibleAppend(obj->getElementSpecific<Type>(i));
+ return DenseElementResult::Success;
+}
+
+DefineBoxedOrUnboxedFunctor3(AppendUnboxedDenseElements,
+ UnboxedArrayObject*, uint32_t, MutableHandle<GCVector<Value>>);
+
+/* static */ bool
+UnboxedArrayObject::convertToNativeWithGroup(ExclusiveContext* cx, JSObject* obj,
+ ObjectGroup* group, Shape* shape)
+{
+ size_t length = obj->as<UnboxedArrayObject>().length();
+ size_t initlen = obj->as<UnboxedArrayObject>().initializedLength();
+
+ Rooted<GCVector<Value>> values(cx, GCVector<Value>(cx));
+ if (!values.reserve(initlen))
+ return false;
+
+ AppendUnboxedDenseElementsFunctor functor(&obj->as<UnboxedArrayObject>(), initlen, &values);
+ DebugOnly<DenseElementResult> result = CallBoxedOrUnboxedSpecialization(functor, obj);
+ MOZ_ASSERT(result.value == DenseElementResult::Success);
+
+ obj->setGroup(group);
+
+ ArrayObject* aobj = &obj->as<ArrayObject>();
+ aobj->setLastPropertyMakeNative(cx, shape);
+
+ // Make sure there is at least one element, so that this array does not
+ // use emptyObjectElements / emptyObjectElementsShared.
+ if (!aobj->ensureElements(cx, Max<size_t>(initlen, 1)))
+ return false;
+
+ MOZ_ASSERT(!aobj->getDenseInitializedLength());
+ aobj->setDenseInitializedLength(initlen);
+ aobj->initDenseElements(0, values.begin(), initlen);
+ aobj->setLengthInt32(length);
+
+ return true;
+}
+
+/* static */ bool
+UnboxedArrayObject::convertToNative(JSContext* cx, JSObject* obj)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedArrayObject>().layout();
+
+ if (!layout.nativeGroup()) {
+ if (!UnboxedLayout::makeNativeGroup(cx, obj->group()))
+ return false;
+ }
+
+ return convertToNativeWithGroup(cx, obj, layout.nativeGroup(), layout.nativeShape());
+}
+
+bool
+UnboxedArrayObject::convertInt32ToDouble(ExclusiveContext* cx, ObjectGroup* group)
+{
+ MOZ_ASSERT(elementType() == JSVAL_TYPE_INT32);
+ MOZ_ASSERT(group->unboxedLayout().elementType() == JSVAL_TYPE_DOUBLE);
+
+ Vector<int32_t> values(cx);
+ if (!values.reserve(initializedLength()))
+ return false;
+ for (size_t i = 0; i < initializedLength(); i++)
+ values.infallibleAppend(getElementSpecific<JSVAL_TYPE_INT32>(i).toInt32());
+
+ uint8_t* newElements;
+ if (hasInlineElements()) {
+ newElements = AllocateObjectBuffer<uint8_t>(cx, this, capacity() * sizeof(double));
+ } else {
+ newElements = ReallocateObjectBuffer<uint8_t>(cx, this, elements(),
+ capacity() * sizeof(int32_t),
+ capacity() * sizeof(double));
+ }
+ if (!newElements)
+ return false;
+
+ setGroup(group);
+ elements_ = newElements;
+
+ for (size_t i = 0; i < initializedLength(); i++)
+ setElementNoTypeChangeSpecific<JSVAL_TYPE_DOUBLE>(i, DoubleValue(values[i]));
+
+ return true;
+}
+
+/* static */ UnboxedArrayObject*
+UnboxedArrayObject::create(ExclusiveContext* cx, HandleObjectGroup group, uint32_t length,
+ NewObjectKind newKind, uint32_t maxLength)
+{
+ MOZ_ASSERT(length <= MaximumCapacity);
+
+ MOZ_ASSERT(group->clasp() == &class_);
+ uint32_t elementSize = UnboxedTypeSize(group->unboxedLayout().elementType());
+ uint32_t capacity = Min(length, maxLength);
+ uint32_t nbytes = offsetOfInlineElements() + elementSize * capacity;
+
+ UnboxedArrayObject* res;
+ if (nbytes <= JSObject::MAX_BYTE_SIZE) {
+ gc::AllocKind allocKind = gc::GetGCObjectKindForBytes(nbytes);
+
+ // If there was no provided length information, pick an allocation kind
+ // to accommodate small arrays (as is done for normal native arrays).
+ if (capacity == 0)
+ allocKind = gc::AllocKind::OBJECT8;
+
+ res = NewObjectWithGroup<UnboxedArrayObject>(cx, group, allocKind, newKind);
+ if (!res)
+ return nullptr;
+ res->setInitializedLengthNoBarrier(0);
+ res->setInlineElements();
+
+ size_t actualCapacity = (GetGCKindBytes(allocKind) - offsetOfInlineElements()) / elementSize;
+ MOZ_ASSERT(actualCapacity >= capacity);
+ res->setCapacityIndex(exactCapacityIndex(actualCapacity));
+ } else {
+ res = NewObjectWithGroup<UnboxedArrayObject>(cx, group, gc::AllocKind::OBJECT0, newKind);
+ if (!res)
+ return nullptr;
+ res->setInitializedLengthNoBarrier(0);
+
+ uint32_t capacityIndex = (capacity == length)
+ ? CapacityMatchesLengthIndex
+ : chooseCapacityIndex(capacity, length);
+ uint32_t actualCapacity = computeCapacity(capacityIndex, length);
+
+ res->elements_ = AllocateObjectBuffer<uint8_t>(cx, res, actualCapacity * elementSize);
+ if (!res->elements_) {
+ // Make the object safe for GC.
+ res->setInlineElements();
+ return nullptr;
+ }
+
+ res->setCapacityIndex(capacityIndex);
+ }
+
+ res->setLength(cx, length);
+ return res;
+}
+
+bool
+UnboxedArrayObject::setElement(ExclusiveContext* cx, size_t index, const Value& v)
+{
+ MOZ_ASSERT(index < initializedLength());
+ uint8_t* p = elements() + index * elementSize();
+ return SetUnboxedValue(cx, this, JSID_VOID, p, elementType(), v, /* preBarrier = */ true);
+}
+
+bool
+UnboxedArrayObject::initElement(ExclusiveContext* cx, size_t index, const Value& v)
+{
+ MOZ_ASSERT(index < initializedLength());
+ uint8_t* p = elements() + index * elementSize();
+ return SetUnboxedValue(cx, this, JSID_VOID, p, elementType(), v, /* preBarrier = */ false);
+}
+
+void
+UnboxedArrayObject::initElementNoTypeChange(size_t index, const Value& v)
+{
+ MOZ_ASSERT(index < initializedLength());
+ uint8_t* p = elements() + index * elementSize();
+ if (UnboxedTypeNeedsPreBarrier(elementType()))
+ *reinterpret_cast<void**>(p) = nullptr;
+ SetUnboxedValueNoTypeChange(this, p, elementType(), v, /* preBarrier = */ false);
+}
+
+Value
+UnboxedArrayObject::getElement(size_t index)
+{
+ MOZ_ASSERT(index < initializedLength());
+ uint8_t* p = elements() + index * elementSize();
+ return GetUnboxedValue(p, elementType(), /* maybeUninitialized = */ false);
+}
+
+/* static */ void
+UnboxedArrayObject::trace(JSTracer* trc, JSObject* obj)
+{
+ JSValueType type = obj->as<UnboxedArrayObject>().elementType();
+ if (!UnboxedTypeNeedsPreBarrier(type))
+ return;
+
+ MOZ_ASSERT(obj->as<UnboxedArrayObject>().elementSize() == sizeof(uintptr_t));
+ size_t initlen = obj->as<UnboxedArrayObject>().initializedLength();
+ void** elements = reinterpret_cast<void**>(obj->as<UnboxedArrayObject>().elements());
+
+ switch (type) {
+ case JSVAL_TYPE_OBJECT:
+ for (size_t i = 0; i < initlen; i++) {
+ GCPtrObject* heap = reinterpret_cast<GCPtrObject*>(elements + i);
+ TraceNullableEdge(trc, heap, "unboxed_object");
+ }
+ break;
+
+ case JSVAL_TYPE_STRING:
+ for (size_t i = 0; i < initlen; i++) {
+ GCPtrString* heap = reinterpret_cast<GCPtrString*>(elements + i);
+ TraceEdge(trc, heap, "unboxed_string");
+ }
+ break;
+
+ default:
+ MOZ_CRASH();
+ }
+}
+
+/* static */ void
+UnboxedArrayObject::objectMoved(JSObject* obj, const JSObject* old)
+{
+ UnboxedArrayObject& dst = obj->as<UnboxedArrayObject>();
+ const UnboxedArrayObject& src = old->as<UnboxedArrayObject>();
+
+ // Fix up possible inline data pointer.
+ if (src.hasInlineElements())
+ dst.setInlineElements();
+}
+
+/* static */ void
+UnboxedArrayObject::finalize(FreeOp* fop, JSObject* obj)
+{
+ MOZ_ASSERT(!IsInsideNursery(obj));
+ if (!obj->as<UnboxedArrayObject>().hasInlineElements())
+ js_free(obj->as<UnboxedArrayObject>().elements());
+}
+
+/* static */ size_t
+UnboxedArrayObject::objectMovedDuringMinorGC(JSTracer* trc, JSObject* dst, JSObject* src,
+ gc::AllocKind allocKind)
+{
+ UnboxedArrayObject* ndst = &dst->as<UnboxedArrayObject>();
+ UnboxedArrayObject* nsrc = &src->as<UnboxedArrayObject>();
+ MOZ_ASSERT(ndst->elements() == nsrc->elements());
+
+ Nursery& nursery = trc->runtime()->gc.nursery;
+
+ if (!nursery.isInside(nsrc->elements())) {
+ nursery.removeMallocedBuffer(nsrc->elements());
+ return 0;
+ }
+
+ // Determine if we can use inline data for the target array. If this is
+ // possible, the nursery will have picked an allocation size that is large
+ // enough.
+ size_t nbytes = nsrc->capacity() * nsrc->elementSize();
+ if (offsetOfInlineElements() + nbytes <= GetGCKindBytes(allocKind)) {
+ ndst->setInlineElements();
+ } else {
+ MOZ_ASSERT(allocKind == gc::AllocKind::OBJECT0);
+
+ AutoEnterOOMUnsafeRegion oomUnsafe;
+ uint8_t* data = nsrc->zone()->pod_malloc<uint8_t>(nbytes);
+ if (!data)
+ oomUnsafe.crash("Failed to allocate unboxed array elements while tenuring.");
+ ndst->elements_ = data;
+ }
+
+ PodCopy(ndst->elements(), nsrc->elements(), nsrc->initializedLength() * nsrc->elementSize());
+
+ // Set a forwarding pointer for the element buffers in case they were
+ // preserved on the stack by Ion.
+ bool direct = nsrc->capacity() * nsrc->elementSize() >= sizeof(uintptr_t);
+ nursery.maybeSetForwardingPointer(trc, nsrc->elements(), ndst->elements(), direct);
+
+ return ndst->hasInlineElements() ? 0 : nbytes;
+}
+
+// Possible capacities for unboxed arrays. Some of these capacities might seem
+// a little weird, but were chosen to allow the inline data of objects of each
+// size to be fully utilized for arrays of the various types on both 32 bit and
+// 64 bit platforms.
+//
+// To find the possible inline capacities, the following script was used:
+//
+// var fixedSlotCapacities = [0, 2, 4, 8, 12, 16];
+// var dataSizes = [1, 4, 8];
+// var header32 = 4 * 2 + 4 * 2;
+// var header64 = 8 * 2 + 4 * 2;
+//
+// for (var i = 0; i < fixedSlotCapacities.length; i++) {
+// var nfixed = fixedSlotCapacities[i];
+// var size32 = 4 * 4 + 8 * nfixed - header32;
+// var size64 = 8 * 4 + 8 * nfixed - header64;
+// for (var j = 0; j < dataSizes.length; j++) {
+// print(size32 / dataSizes[j]);
+// print(size64 / dataSizes[j]);
+// }
+// }
+//
+/* static */ const uint32_t
+UnboxedArrayObject::CapacityArray[] = {
+ UINT32_MAX, // For CapacityMatchesLengthIndex.
+ 0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 13, 16, 17, 18, 24, 26, 32, 34, 40, 64, 72, 96, 104, 128, 136,
+ 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288,
+ 1048576, 2097152, 3145728, 4194304, 5242880, 6291456, 7340032, 8388608, 9437184, 11534336,
+ 13631488, 15728640, 17825792, 20971520, 24117248, 27262976, 31457280, 35651584, 40894464,
+ 46137344, 52428800, 59768832, MaximumCapacity
+};
+
+static const uint32_t
+Pow2CapacityIndexes[] = {
+ 2, // 1
+ 3, // 2
+ 5, // 4
+ 8, // 8
+ 13, // 16
+ 18, // 32
+ 21, // 64
+ 25, // 128
+ 27, // 256
+ 28, // 512
+ 29, // 1024
+ 30, // 2048
+ 31, // 4096
+ 32, // 8192
+ 33, // 16384
+ 34, // 32768
+ 35, // 65536
+ 36, // 131072
+ 37, // 262144
+ 38, // 524288
+ 39 // 1048576
+};
+
+static const uint32_t MebiCapacityIndex = 39;
+
+/* static */ uint32_t
+UnboxedArrayObject::chooseCapacityIndex(uint32_t capacity, uint32_t length)
+{
+ // Note: the structure and behavior of this method follow along with
+ // NativeObject::goodAllocated. Changes to the allocation strategy in one
+ // should generally be matched by the other.
+
+ // Make sure we have enough space to store all possible values for the capacity index.
+ // This ought to be a static_assert, but MSVC doesn't like that.
+ MOZ_ASSERT(mozilla::ArrayLength(CapacityArray) - 1 <= (CapacityMask >> CapacityShift));
+
+ // The caller should have ensured the capacity is possible for an unboxed array.
+ MOZ_ASSERT(capacity <= MaximumCapacity);
+
+ static const uint32_t Mebi = 1024 * 1024;
+
+ if (capacity <= Mebi) {
+ capacity = mozilla::RoundUpPow2(capacity);
+
+ // When the required capacity is close to the array length, then round
+ // up to the array length itself, as for NativeObject.
+ if (length >= capacity && capacity > (length / 3) * 2)
+ return CapacityMatchesLengthIndex;
+
+ if (capacity < MinimumDynamicCapacity)
+ capacity = MinimumDynamicCapacity;
+
+ uint32_t bit = mozilla::FloorLog2Size(capacity);
+ MOZ_ASSERT(capacity == uint32_t(1 << bit));
+ MOZ_ASSERT(bit <= 20);
+ MOZ_ASSERT(mozilla::ArrayLength(Pow2CapacityIndexes) == 21);
+
+ uint32_t index = Pow2CapacityIndexes[bit];
+ MOZ_ASSERT(CapacityArray[index] == capacity);
+
+ return index;
+ }
+
+ MOZ_ASSERT(CapacityArray[MebiCapacityIndex] == Mebi);
+
+ for (uint32_t i = MebiCapacityIndex + 1;; i++) {
+ if (CapacityArray[i] >= capacity)
+ return i;
+ }
+
+ MOZ_CRASH("Invalid capacity");
+}
+
+/* static */ uint32_t
+UnboxedArrayObject::exactCapacityIndex(uint32_t capacity)
+{
+ for (size_t i = CapacityMatchesLengthIndex + 1; i < ArrayLength(CapacityArray); i++) {
+ if (CapacityArray[i] == capacity)
+ return i;
+ }
+ MOZ_CRASH();
+}
+
+bool
+UnboxedArrayObject::growElements(ExclusiveContext* cx, size_t cap)
+{
+ // The caller should have checked if this capacity is possible for an
+ // unboxed array, so the only way this call can fail is from OOM.
+ MOZ_ASSERT(cap <= MaximumCapacity);
+
+ uint32_t oldCapacity = capacity();
+ uint32_t newCapacityIndex = chooseCapacityIndex(cap, length());
+ uint32_t newCapacity = computeCapacity(newCapacityIndex, length());
+
+ MOZ_ASSERT(oldCapacity < cap);
+ MOZ_ASSERT(cap <= newCapacity);
+
+ // The allocation size computation below cannot have integer overflows.
+ JS_STATIC_ASSERT(MaximumCapacity < UINT32_MAX / sizeof(double));
+
+ uint8_t* newElements;
+ if (hasInlineElements()) {
+ newElements = AllocateObjectBuffer<uint8_t>(cx, this, newCapacity * elementSize());
+ if (!newElements)
+ return false;
+ js_memcpy(newElements, elements(), initializedLength() * elementSize());
+ } else {
+ newElements = ReallocateObjectBuffer<uint8_t>(cx, this, elements(),
+ oldCapacity * elementSize(),
+ newCapacity * elementSize());
+ if (!newElements)
+ return false;
+ }
+
+ elements_ = newElements;
+ setCapacityIndex(newCapacityIndex);
+
+ return true;
+}
+
+void
+UnboxedArrayObject::shrinkElements(ExclusiveContext* cx, size_t cap)
+{
+ if (hasInlineElements())
+ return;
+
+ uint32_t oldCapacity = capacity();
+ uint32_t newCapacityIndex = chooseCapacityIndex(cap, 0);
+ uint32_t newCapacity = computeCapacity(newCapacityIndex, 0);
+
+ MOZ_ASSERT(cap < oldCapacity);
+ MOZ_ASSERT(cap <= newCapacity);
+
+ if (newCapacity >= oldCapacity)
+ return;
+
+ uint8_t* newElements = ReallocateObjectBuffer<uint8_t>(cx, this, elements(),
+ oldCapacity * elementSize(),
+ newCapacity * elementSize());
+ if (!newElements)
+ return;
+
+ elements_ = newElements;
+ setCapacityIndex(newCapacityIndex);
+}
+
+bool
+UnboxedArrayObject::containsProperty(ExclusiveContext* cx, jsid id)
+{
+ if (JSID_IS_INT(id) && uint32_t(JSID_TO_INT(id)) < initializedLength())
+ return true;
+ if (JSID_IS_ATOM(id) && JSID_TO_ATOM(id) == cx->names().length)
+ return true;
+ return false;
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_lookupProperty(JSContext* cx, HandleObject obj,
+ HandleId id, MutableHandleObject objp,
+ MutableHandleShape propp)
+{
+ if (obj->as<UnboxedArrayObject>().containsProperty(cx, id)) {
+ MarkNonNativePropertyFound<CanGC>(propp);
+ objp.set(obj);
+ return true;
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ objp.set(nullptr);
+ propp.set(nullptr);
+ return true;
+ }
+
+ return LookupProperty(cx, proto, id, objp, propp);
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_defineProperty(JSContext* cx, HandleObject obj, HandleId id,
+ Handle<PropertyDescriptor> desc,
+ ObjectOpResult& result)
+{
+ if (JSID_IS_INT(id) && !desc.getter() && !desc.setter() && desc.attributes() == JSPROP_ENUMERATE) {
+ UnboxedArrayObject* nobj = &obj->as<UnboxedArrayObject>();
+
+ uint32_t index = JSID_TO_INT(id);
+ if (index < nobj->initializedLength()) {
+ if (nobj->setElement(cx, index, desc.value()))
+ return result.succeed();
+ } else if (index == nobj->initializedLength() && index < MaximumCapacity) {
+ if (nobj->initializedLength() == nobj->capacity()) {
+ if (!nobj->growElements(cx, index + 1))
+ return false;
+ }
+ nobj->setInitializedLength(index + 1);
+ if (nobj->initElement(cx, index, desc.value())) {
+ if (nobj->length() <= index)
+ nobj->setLengthInt32(index + 1);
+ return result.succeed();
+ }
+ nobj->setInitializedLengthNoBarrier(index);
+ }
+ }
+
+ if (!convertToNative(cx, obj))
+ return false;
+
+ return DefineProperty(cx, obj, id, desc, result);
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_hasProperty(JSContext* cx, HandleObject obj, HandleId id, bool* foundp)
+{
+ if (obj->as<UnboxedArrayObject>().containsProperty(cx, id)) {
+ *foundp = true;
+ return true;
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ *foundp = false;
+ return true;
+ }
+
+ return HasProperty(cx, proto, id, foundp);
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_getProperty(JSContext* cx, HandleObject obj, HandleValue receiver,
+ HandleId id, MutableHandleValue vp)
+{
+ if (obj->as<UnboxedArrayObject>().containsProperty(cx, id)) {
+ if (JSID_IS_INT(id))
+ vp.set(obj->as<UnboxedArrayObject>().getElement(JSID_TO_INT(id)));
+ else
+ vp.set(Int32Value(obj->as<UnboxedArrayObject>().length()));
+ return true;
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ vp.setUndefined();
+ return true;
+ }
+
+ return GetProperty(cx, proto, receiver, id, vp);
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_setProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v,
+ HandleValue receiver, ObjectOpResult& result)
+{
+ if (obj->as<UnboxedArrayObject>().containsProperty(cx, id)) {
+ if (receiver.isObject() && obj == &receiver.toObject()) {
+ if (JSID_IS_INT(id)) {
+ if (obj->as<UnboxedArrayObject>().setElement(cx, JSID_TO_INT(id), v))
+ return result.succeed();
+ } else {
+ uint32_t len;
+ if (!CanonicalizeArrayLengthValue(cx, v, &len))
+ return false;
+ UnboxedArrayObject* nobj = &obj->as<UnboxedArrayObject>();
+ if (len < nobj->initializedLength()) {
+ nobj->setInitializedLength(len);
+ nobj->shrinkElements(cx, len);
+ }
+ nobj->setLength(cx, len);
+ return result.succeed();
+ }
+
+ if (!convertToNative(cx, obj))
+ return false;
+ return SetProperty(cx, obj, id, v, receiver, result);
+ }
+
+ return SetPropertyByDefining(cx, id, v, receiver, result);
+ }
+
+ return SetPropertyOnProto(cx, obj, id, v, receiver, result);
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_getOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id,
+ MutableHandle<PropertyDescriptor> desc)
+{
+ if (obj->as<UnboxedArrayObject>().containsProperty(cx, id)) {
+ if (JSID_IS_INT(id)) {
+ desc.value().set(obj->as<UnboxedArrayObject>().getElement(JSID_TO_INT(id)));
+ desc.setAttributes(JSPROP_ENUMERATE);
+ } else {
+ desc.value().set(Int32Value(obj->as<UnboxedArrayObject>().length()));
+ desc.setAttributes(JSPROP_PERMANENT);
+ }
+ desc.object().set(obj);
+ return true;
+ }
+
+ desc.object().set(nullptr);
+ return true;
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_deleteProperty(JSContext* cx, HandleObject obj, HandleId id,
+ ObjectOpResult& result)
+{
+ if (obj->as<UnboxedArrayObject>().containsProperty(cx, id)) {
+ size_t initlen = obj->as<UnboxedArrayObject>().initializedLength();
+ if (JSID_IS_INT(id) && JSID_TO_INT(id) == int32_t(initlen - 1)) {
+ obj->as<UnboxedArrayObject>().setInitializedLength(initlen - 1);
+ obj->as<UnboxedArrayObject>().shrinkElements(cx, initlen - 1);
+ return result.succeed();
+ }
+ }
+
+ if (!convertToNative(cx, obj))
+ return false;
+ return DeleteProperty(cx, obj, id, result);
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_watch(JSContext* cx, HandleObject obj, HandleId id, HandleObject callable)
+{
+ if (!convertToNative(cx, obj))
+ return false;
+ return WatchProperty(cx, obj, id, callable);
+}
+
+/* static */ bool
+UnboxedArrayObject::obj_enumerate(JSContext* cx, HandleObject obj, AutoIdVector& properties,
+ bool enumerableOnly)
+{
+ for (size_t i = 0; i < obj->as<UnboxedArrayObject>().initializedLength(); i++) {
+ if (!properties.append(INT_TO_JSID(i)))
+ return false;
+ }
+
+ if (!enumerableOnly && !properties.append(NameToId(cx->names().length)))
+ return false;
+
+ return true;
+}
+
+static const ClassOps UnboxedArrayObjectClassOps = {
+ nullptr, /* addProperty */
+ nullptr, /* delProperty */
+ nullptr, /* getProperty */
+ nullptr, /* setProperty */
+ nullptr, /* enumerate */
+ nullptr, /* resolve */
+ nullptr, /* mayResolve */
+ UnboxedArrayObject::finalize,
+ nullptr, /* call */
+ nullptr, /* hasInstance */
+ nullptr, /* construct */
+ UnboxedArrayObject::trace,
+};
+
+static const ClassExtension UnboxedArrayObjectClassExtension = {
+ nullptr, /* weakmapKeyDelegateOp */
+ UnboxedArrayObject::objectMoved
+};
+
+static const ObjectOps UnboxedArrayObjectObjectOps = {
+ UnboxedArrayObject::obj_lookupProperty,
+ UnboxedArrayObject::obj_defineProperty,
+ UnboxedArrayObject::obj_hasProperty,
+ UnboxedArrayObject::obj_getProperty,
+ UnboxedArrayObject::obj_setProperty,
+ UnboxedArrayObject::obj_getOwnPropertyDescriptor,
+ UnboxedArrayObject::obj_deleteProperty,
+ UnboxedArrayObject::obj_watch,
+ nullptr, /* No unwatch needed, as watch() converts the object to native */
+ nullptr, /* getElements */
+ UnboxedArrayObject::obj_enumerate,
+ nullptr /* funToString */
+};
+
+const Class UnboxedArrayObject::class_ = {
+ "Array",
+ Class::NON_NATIVE |
+ JSCLASS_SKIP_NURSERY_FINALIZE |
+ JSCLASS_BACKGROUND_FINALIZE,
+ &UnboxedArrayObjectClassOps,
+ JS_NULL_CLASS_SPEC,
+ &UnboxedArrayObjectClassExtension,
+ &UnboxedArrayObjectObjectOps
+};
+
+/////////////////////////////////////////////////////////////////////
+// API
+/////////////////////////////////////////////////////////////////////
+
+static bool
+UnboxedTypeIncludes(JSValueType supertype, JSValueType subtype)
+{
+ if (supertype == JSVAL_TYPE_DOUBLE && subtype == JSVAL_TYPE_INT32)
+ return true;
+ if (supertype == JSVAL_TYPE_OBJECT && subtype == JSVAL_TYPE_NULL)
+ return true;
+ return false;
+}
+
+static bool
+CombineUnboxedTypes(const Value& value, JSValueType* existing)
+{
+ JSValueType type = value.isDouble() ? JSVAL_TYPE_DOUBLE : value.extractNonDoubleType();
+
+ if (*existing == JSVAL_TYPE_MAGIC || *existing == type || UnboxedTypeIncludes(type, *existing)) {
+ *existing = type;
+ return true;
+ }
+ if (UnboxedTypeIncludes(*existing, type))
+ return true;
+ return false;
+}
+
+// Return whether the property names and types in layout are a subset of the
+// specified vector.
+static bool
+PropertiesAreSuperset(const UnboxedLayout::PropertyVector& properties, UnboxedLayout* layout)
+{
+ for (size_t i = 0; i < layout->properties().length(); i++) {
+ const UnboxedLayout::Property& layoutProperty = layout->properties()[i];
+ bool found = false;
+ for (size_t j = 0; j < properties.length(); j++) {
+ if (layoutProperty.name == properties[j].name) {
+ found = (layoutProperty.type == properties[j].type);
+ break;
+ }
+ }
+ if (!found)
+ return false;
+ }
+ return true;
+}
+
+static bool
+CombinePlainObjectProperties(PlainObject* obj, Shape* templateShape,
+ UnboxedLayout::PropertyVector& properties)
+{
+ // All preliminary objects must have been created with enough space to
+ // fill in their unboxed data inline. This is ensured either by using
+ // the largest allocation kind (which limits the maximum size of an
+ // unboxed object), or by using an allocation kind that covers all
+ // properties in the template, as the space used by unboxed properties
+ // is less than or equal to that used by boxed properties.
+ MOZ_ASSERT(gc::GetGCKindSlots(obj->asTenured().getAllocKind()) >=
+ Min(NativeObject::MAX_FIXED_SLOTS, templateShape->slotSpan()));
+
+ if (obj->lastProperty() != templateShape || obj->hasDynamicElements()) {
+ // Only use an unboxed representation if all created objects match
+ // the template shape exactly.
+ return false;
+ }
+
+ for (size_t i = 0; i < templateShape->slotSpan(); i++) {
+ Value val = obj->getSlot(i);
+
+ JSValueType& existing = properties[i].type;
+ if (!CombineUnboxedTypes(val, &existing))
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+CombineArrayObjectElements(ExclusiveContext* cx, ArrayObject* obj, JSValueType* elementType)
+{
+ if (obj->inDictionaryMode() ||
+ obj->lastProperty()->propid() != AtomToId(cx->names().length) ||
+ !obj->lastProperty()->previous()->isEmptyShape())
+ {
+ // Only use an unboxed representation if the object has no properties.
+ return false;
+ }
+
+ for (size_t i = 0; i < obj->getDenseInitializedLength(); i++) {
+ Value val = obj->getDenseElement(i);
+
+ // For now, unboxed arrays cannot have holes.
+ if (val.isMagic(JS_ELEMENTS_HOLE))
+ return false;
+
+ if (!CombineUnboxedTypes(val, elementType))
+ return false;
+ }
+
+ return true;
+}
+
+static size_t
+ComputePlainObjectLayout(ExclusiveContext* cx, Shape* templateShape,
+ UnboxedLayout::PropertyVector& properties)
+{
+ // Fill in the names for all the object's properties.
+ for (Shape::Range<NoGC> r(templateShape); !r.empty(); r.popFront()) {
+ size_t slot = r.front().slot();
+ MOZ_ASSERT(!properties[slot].name);
+ properties[slot].name = JSID_TO_ATOM(r.front().propid())->asPropertyName();
+ }
+
+ // Fill in all the unboxed object's property offsets.
+ uint32_t offset = 0;
+
+ // Search for an existing unboxed layout which is a subset of this one.
+ // If there are multiple such layouts, use the largest one. If we're able
+ // to find such a layout, use the same property offsets for the shared
+ // properties, which will allow us to generate better code if the objects
+ // have a subtype/supertype relation and are accessed at common sites.
+ UnboxedLayout* bestExisting = nullptr;
+ for (UnboxedLayout* existing : cx->compartment()->unboxedLayouts) {
+ if (PropertiesAreSuperset(properties, existing)) {
+ if (!bestExisting ||
+ existing->properties().length() > bestExisting->properties().length())
+ {
+ bestExisting = existing;
+ }
+ }
+ }
+ if (bestExisting) {
+ for (size_t i = 0; i < bestExisting->properties().length(); i++) {
+ const UnboxedLayout::Property& existingProperty = bestExisting->properties()[i];
+ for (size_t j = 0; j < templateShape->slotSpan(); j++) {
+ if (existingProperty.name == properties[j].name) {
+ MOZ_ASSERT(existingProperty.type == properties[j].type);
+ properties[j].offset = existingProperty.offset;
+ }
+ }
+ }
+ offset = bestExisting->size();
+ }
+
+ // Order remaining properties from the largest down for the best space
+ // utilization.
+ static const size_t typeSizes[] = { 8, 4, 1 };
+
+ for (size_t i = 0; i < ArrayLength(typeSizes); i++) {
+ size_t size = typeSizes[i];
+ for (size_t j = 0; j < templateShape->slotSpan(); j++) {
+ if (properties[j].offset != UINT32_MAX)
+ continue;
+ JSValueType type = properties[j].type;
+ if (UnboxedTypeSize(type) == size) {
+ offset = JS_ROUNDUP(offset, size);
+ properties[j].offset = offset;
+ offset += size;
+ }
+ }
+ }
+
+ // The final offset is the amount of data needed by the object.
+ return offset;
+}
+
+static bool
+SetLayoutTraceList(ExclusiveContext* cx, UnboxedLayout* layout)
+{
+ // Figure out the offsets of any objects or string properties.
+ Vector<int32_t, 8, SystemAllocPolicy> objectOffsets, stringOffsets;
+ for (size_t i = 0; i < layout->properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout->properties()[i];
+ MOZ_ASSERT(property.offset != UINT32_MAX);
+ if (property.type == JSVAL_TYPE_OBJECT) {
+ if (!objectOffsets.append(property.offset))
+ return false;
+ } else if (property.type == JSVAL_TYPE_STRING) {
+ if (!stringOffsets.append(property.offset))
+ return false;
+ }
+ }
+
+ // Construct the layout's trace list.
+ if (!objectOffsets.empty() || !stringOffsets.empty()) {
+ Vector<int32_t, 8, SystemAllocPolicy> entries;
+ if (!entries.appendAll(stringOffsets) ||
+ !entries.append(-1) ||
+ !entries.appendAll(objectOffsets) ||
+ !entries.append(-1) ||
+ !entries.append(-1))
+ {
+ return false;
+ }
+ int32_t* traceList = cx->zone()->pod_malloc<int32_t>(entries.length());
+ if (!traceList)
+ return false;
+ PodCopy(traceList, entries.begin(), entries.length());
+ layout->setTraceList(traceList);
+ }
+
+ return true;
+}
+
+static inline Value
+NextValue(Handle<GCVector<Value>> values, size_t* valueCursor)
+{
+ return values[(*valueCursor)++];
+}
+
+static bool
+GetValuesFromPreliminaryArrayObject(ArrayObject* obj, MutableHandle<GCVector<Value>> values)
+{
+ if (!values.append(Int32Value(obj->length())))
+ return false;
+ if (!values.append(Int32Value(obj->getDenseInitializedLength())))
+ return false;
+ for (size_t i = 0; i < obj->getDenseInitializedLength(); i++) {
+ if (!values.append(obj->getDenseElement(i)))
+ return false;
+ }
+ return true;
+}
+
+void
+UnboxedArrayObject::fillAfterConvert(ExclusiveContext* cx,
+ Handle<GCVector<Value>> values, size_t* valueCursor)
+{
+ MOZ_ASSERT(CapacityArray[1] == 0);
+ setCapacityIndex(1);
+ setInitializedLengthNoBarrier(0);
+ setInlineElements();
+
+ setLength(cx, NextValue(values, valueCursor).toInt32());
+
+ int32_t initlen = NextValue(values, valueCursor).toInt32();
+ if (!initlen)
+ return;
+
+ AutoEnterOOMUnsafeRegion oomUnsafe;
+ if (!growElements(cx, initlen))
+ oomUnsafe.crash("UnboxedArrayObject::fillAfterConvert");
+
+ setInitializedLength(initlen);
+
+ for (size_t i = 0; i < size_t(initlen); i++)
+ JS_ALWAYS_TRUE(initElement(cx, i, NextValue(values, valueCursor)));
+}
+
+static bool
+GetValuesFromPreliminaryPlainObject(PlainObject* obj, MutableHandle<GCVector<Value>> values)
+{
+ for (size_t i = 0; i < obj->slotSpan(); i++) {
+ if (!values.append(obj->getSlot(i)))
+ return false;
+ }
+ return true;
+}
+
+void
+UnboxedPlainObject::fillAfterConvert(ExclusiveContext* cx,
+ Handle<GCVector<Value>> values, size_t* valueCursor)
+{
+ initExpando();
+ memset(data(), 0, layout().size());
+ for (size_t i = 0; i < layout().properties().length(); i++)
+ JS_ALWAYS_TRUE(setValue(cx, layout().properties()[i], NextValue(values, valueCursor)));
+}
+
+bool
+js::TryConvertToUnboxedLayout(ExclusiveContext* cx, AutoEnterAnalysis& enter, Shape* templateShape,
+ ObjectGroup* group, PreliminaryObjectArray* objects)
+{
+ bool isArray = !templateShape;
+
+ // Unboxed arrays are nightly only for now. The getenv() call will be
+ // removed when they are on by default. See bug 1153266.
+ if (isArray) {
+#ifdef NIGHTLY_BUILD
+ if (!getenv("JS_OPTION_USE_UNBOXED_ARRAYS")) {
+ if (!cx->options().unboxedArrays())
+ return true;
+ }
+#else
+ return true;
+#endif
+ } else {
+ if (jit::JitOptions.disableUnboxedObjects)
+ return true;
+ }
+
+ MOZ_ASSERT_IF(templateShape, !templateShape->getObjectFlags());
+
+ if (group->runtimeFromAnyThread()->isSelfHostingGlobal(cx->global()))
+ return true;
+
+ if (!isArray && templateShape->slotSpan() == 0)
+ return true;
+
+ UnboxedLayout::PropertyVector properties;
+ if (!isArray) {
+ if (!properties.appendN(UnboxedLayout::Property(), templateShape->slotSpan()))
+ return false;
+ }
+ JSValueType elementType = JSVAL_TYPE_MAGIC;
+
+ size_t objectCount = 0;
+ for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) {
+ JSObject* obj = objects->get(i);
+ if (!obj)
+ continue;
+
+ if (obj->isSingleton() || obj->group() != group)
+ return true;
+
+ objectCount++;
+
+ if (isArray) {
+ if (!CombineArrayObjectElements(cx, &obj->as<ArrayObject>(), &elementType))
+ return true;
+ } else {
+ if (!CombinePlainObjectProperties(&obj->as<PlainObject>(), templateShape, properties))
+ return true;
+ }
+ }
+
+ size_t layoutSize = 0;
+ if (isArray) {
+ // Don't use an unboxed representation if we couldn't determine an
+ // element type for the objects.
+ if (UnboxedTypeSize(elementType) == 0)
+ return true;
+ } else {
+ if (objectCount <= 1) {
+ // If only one of the objects has been created, it is more likely
+ // to have new properties added later. This heuristic is not used
+ // for array objects, where we might want an unboxed representation
+ // even if there is only one large array.
+ return true;
+ }
+
+ for (size_t i = 0; i < templateShape->slotSpan(); i++) {
+ // We can't use an unboxed representation if e.g. all the objects have
+ // a null value for one of the properties, as we can't decide what type
+ // it is supposed to have.
+ if (UnboxedTypeSize(properties[i].type) == 0)
+ return true;
+ }
+
+ // Make sure that all properties on the template shape are property
+ // names, and not indexes.
+ for (Shape::Range<NoGC> r(templateShape); !r.empty(); r.popFront()) {
+ jsid id = r.front().propid();
+ uint32_t dummy;
+ if (!JSID_IS_ATOM(id) || JSID_TO_ATOM(id)->isIndex(&dummy))
+ return true;
+ }
+
+ layoutSize = ComputePlainObjectLayout(cx, templateShape, properties);
+
+ // The entire object must be allocatable inline.
+ if (UnboxedPlainObject::offsetOfData() + layoutSize > JSObject::MAX_BYTE_SIZE)
+ return true;
+ }
+
+ UniquePtr<UnboxedLayout>& layout = enter.unboxedLayoutToCleanUp;
+ MOZ_ASSERT(!layout);
+ layout = group->zone()->make_unique<UnboxedLayout>();
+ if (!layout)
+ return false;
+
+ if (isArray) {
+ layout->initArray(elementType);
+ } else {
+ if (!layout->initProperties(properties, layoutSize))
+ return false;
+
+ // The unboxedLayouts list only tracks layouts for plain objects.
+ cx->compartment()->unboxedLayouts.insertFront(layout.get());
+
+ if (!SetLayoutTraceList(cx, layout.get()))
+ return false;
+ }
+
+ // We've determined that all the preliminary objects can use the new layout
+ // just constructed, so convert the existing group to use the unboxed class,
+ // and update the preliminary objects to use the new layout. Do the
+ // fallible stuff first before modifying any objects.
+
+ // Get an empty shape which we can use for the preliminary objects.
+ const Class* clasp = isArray ? &UnboxedArrayObject::class_ : &UnboxedPlainObject::class_;
+ Shape* newShape = EmptyShape::getInitialShape(cx, clasp, group->proto(), 0);
+ if (!newShape) {
+ cx->recoverFromOutOfMemory();
+ return false;
+ }
+
+ // Accumulate a list of all the values in each preliminary object, and
+ // update their shapes.
+ Rooted<GCVector<Value>> values(cx, GCVector<Value>(cx));
+ for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) {
+ JSObject* obj = objects->get(i);
+ if (!obj)
+ continue;
+
+ bool ok;
+ if (isArray)
+ ok = GetValuesFromPreliminaryArrayObject(&obj->as<ArrayObject>(), &values);
+ else
+ ok = GetValuesFromPreliminaryPlainObject(&obj->as<PlainObject>(), &values);
+
+ if (!ok) {
+ cx->recoverFromOutOfMemory();
+ return false;
+ }
+ }
+
+ if (TypeNewScript* newScript = group->newScript())
+ layout->setNewScript(newScript);
+
+ for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) {
+ if (JSObject* obj = objects->get(i))
+ obj->as<NativeObject>().setLastPropertyMakeNonNative(newShape);
+ }
+
+ group->setClasp(clasp);
+ group->setUnboxedLayout(layout.release());
+
+ size_t valueCursor = 0;
+ for (size_t i = 0; i < PreliminaryObjectArray::COUNT; i++) {
+ JSObject* obj = objects->get(i);
+ if (!obj)
+ continue;
+
+ if (isArray)
+ obj->as<UnboxedArrayObject>().fillAfterConvert(cx, values, &valueCursor);
+ else
+ obj->as<UnboxedPlainObject>().fillAfterConvert(cx, values, &valueCursor);
+ }
+
+ MOZ_ASSERT(valueCursor == values.length());
+ return true;
+}
+
+DefineBoxedOrUnboxedFunctor6(SetOrExtendBoxedOrUnboxedDenseElements,
+ ExclusiveContext*, JSObject*, uint32_t, const Value*, uint32_t,
+ ShouldUpdateTypes);
+
+DenseElementResult
+js::SetOrExtendAnyBoxedOrUnboxedDenseElements(ExclusiveContext* cx, JSObject* obj,
+ uint32_t start, const Value* vp, uint32_t count,
+ ShouldUpdateTypes updateTypes)
+{
+ SetOrExtendBoxedOrUnboxedDenseElementsFunctor functor(cx, obj, start, vp, count, updateTypes);
+ return CallBoxedOrUnboxedSpecialization(functor, obj);
+};
+
+DefineBoxedOrUnboxedFunctor5(MoveBoxedOrUnboxedDenseElements,
+ JSContext*, JSObject*, uint32_t, uint32_t, uint32_t);
+
+DenseElementResult
+js::MoveAnyBoxedOrUnboxedDenseElements(JSContext* cx, JSObject* obj,
+ uint32_t dstStart, uint32_t srcStart, uint32_t length)
+{
+ MoveBoxedOrUnboxedDenseElementsFunctor functor(cx, obj, dstStart, srcStart, length);
+ return CallBoxedOrUnboxedSpecialization(functor, obj);
+}
+
+DefineBoxedOrUnboxedFunctorPair6(CopyBoxedOrUnboxedDenseElements,
+ JSContext*, JSObject*, JSObject*, uint32_t, uint32_t, uint32_t);
+
+DenseElementResult
+js::CopyAnyBoxedOrUnboxedDenseElements(JSContext* cx, JSObject* dst, JSObject* src,
+ uint32_t dstStart, uint32_t srcStart, uint32_t length)
+{
+ CopyBoxedOrUnboxedDenseElementsFunctor functor(cx, dst, src, dstStart, srcStart, length);
+ return CallBoxedOrUnboxedSpecialization(functor, dst, src);
+}
+
+DefineBoxedOrUnboxedFunctor3(SetBoxedOrUnboxedInitializedLength,
+ JSContext*, JSObject*, size_t);
+
+void
+js::SetAnyBoxedOrUnboxedInitializedLength(JSContext* cx, JSObject* obj, size_t initlen)
+{
+ SetBoxedOrUnboxedInitializedLengthFunctor functor(cx, obj, initlen);
+ JS_ALWAYS_TRUE(CallBoxedOrUnboxedSpecialization(functor, obj) == DenseElementResult::Success);
+}
+
+DefineBoxedOrUnboxedFunctor3(EnsureBoxedOrUnboxedDenseElements,
+ JSContext*, JSObject*, size_t);
+
+DenseElementResult
+js::EnsureAnyBoxedOrUnboxedDenseElements(JSContext* cx, JSObject* obj, size_t initlen)
+{
+ EnsureBoxedOrUnboxedDenseElementsFunctor functor(cx, obj, initlen);
+ return CallBoxedOrUnboxedSpecialization(functor, obj);
+}