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/* -*- 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/. */
/*
* JS object implementation.
*/
#include "jsobjinlines.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/SizePrintfMacros.h"
#include "mozilla/TemplateLib.h"
#include "mozilla/UniquePtr.h"
#include <string.h>
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsfriendapi.h"
#include "jsfun.h"
#include "jsgc.h"
#include "jsiter.h"
#include "jsnum.h"
#include "jsopcode.h"
#include "jsprf.h"
#include "jsscript.h"
#include "jsstr.h"
#include "jstypes.h"
#include "jsutil.h"
#include "jswatchpoint.h"
#include "jswin.h"
#include "jswrapper.h"
#include "asmjs/AsmJSModule.h"
#include "builtin/Eval.h"
#include "builtin/Object.h"
#include "builtin/SymbolObject.h"
#include "frontend/BytecodeCompiler.h"
#include "gc/Marking.h"
#include "jit/BaselineJIT.h"
#include "js/MemoryMetrics.h"
#include "js/Proxy.h"
#include "js/UbiNode.h"
#include "vm/ArgumentsObject.h"
#include "vm/Interpreter.h"
#include "vm/ProxyObject.h"
#include "vm/RegExpStaticsObject.h"
#include "vm/Shape.h"
#include "vm/TypedArrayCommon.h"
#include "jsatominlines.h"
#include "jsboolinlines.h"
#include "jscntxtinlines.h"
#include "jscompartmentinlines.h"
#include "vm/ArrayObject-inl.h"
#include "vm/BooleanObject-inl.h"
#include "vm/Interpreter-inl.h"
#include "vm/NativeObject-inl.h"
#include "vm/NumberObject-inl.h"
#include "vm/Runtime-inl.h"
#include "vm/Shape-inl.h"
#include "vm/StringObject-inl.h"
using namespace js;
using namespace js::gc;
using mozilla::DebugOnly;
using mozilla::Maybe;
using mozilla::UniquePtr;
void
js::ReportNotObject(JSContext* cx, const Value& v)
{
MOZ_ASSERT(!v.isObject());
RootedValue value(cx, v);
UniquePtr<char[], JS::FreePolicy> bytes =
DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, value, nullptr);
if (bytes)
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT, bytes.get());
}
const char*
js::InformalValueTypeName(const Value& v)
{
if (v.isObject())
return v.toObject().getClass()->name;
if (v.isString())
return "string";
if (v.isSymbol())
return "symbol";
if (v.isNumber())
return "number";
if (v.isBoolean())
return "boolean";
if (v.isNull())
return "null";
if (v.isUndefined())
return "undefined";
return "value";
}
// ES6 draft rev37 6.2.4.4 FromPropertyDescriptor
bool
js::FromPropertyDescriptor(JSContext* cx, Handle<PropertyDescriptor> desc, MutableHandleValue vp)
{
// Step 1.
if (!desc.object()) {
vp.setUndefined();
return true;
}
return FromPropertyDescriptorToObject(cx, desc, vp);
}
bool
js::FromPropertyDescriptorToObject(JSContext* cx, Handle<PropertyDescriptor> desc,
MutableHandleValue vp)
{
// Step 2-3.
RootedObject obj(cx, NewBuiltinClassInstance<PlainObject>(cx));
if (!obj)
return false;
const JSAtomState& names = cx->names();
// Step 4.
if (desc.hasValue()) {
if (!DefineProperty(cx, obj, names.value, desc.value()))
return false;
}
// Step 5.
RootedValue v(cx);
if (desc.hasWritable()) {
v.setBoolean(desc.writable());
if (!DefineProperty(cx, obj, names.writable, v))
return false;
}
// Step 6.
if (desc.hasGetterObject()) {
if (JSObject* get = desc.getterObject())
v.setObject(*get);
else
v.setUndefined();
if (!DefineProperty(cx, obj, names.get, v))
return false;
}
// Step 7.
if (desc.hasSetterObject()) {
if (JSObject* set = desc.setterObject())
v.setObject(*set);
else
v.setUndefined();
if (!DefineProperty(cx, obj, names.set, v))
return false;
}
// Step 8.
if (desc.hasEnumerable()) {
v.setBoolean(desc.enumerable());
if (!DefineProperty(cx, obj, names.enumerable, v))
return false;
}
// Step 9.
if (desc.hasConfigurable()) {
v.setBoolean(desc.configurable());
if (!DefineProperty(cx, obj, names.configurable, v))
return false;
}
vp.setObject(*obj);
return true;
}
bool
js::GetFirstArgumentAsObject(JSContext* cx, const CallArgs& args, const char* method,
MutableHandleObject objp)
{
if (args.length() == 0) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
method, "0", "s");
return false;
}
HandleValue v = args[0];
if (!v.isObject()) {
UniquePtr<char[], JS::FreePolicy> bytes =
DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, v, nullptr);
if (!bytes)
return false;
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_UNEXPECTED_TYPE,
bytes.get(), "not an object");
return false;
}
objp.set(&v.toObject());
return true;
}
static bool
GetPropertyIfPresent(JSContext* cx, HandleObject obj, HandleId id, MutableHandleValue vp,
bool* foundp)
{
if (!HasProperty(cx, obj, id, foundp))
return false;
if (!*foundp) {
vp.setUndefined();
return true;
}
return GetProperty(cx, obj, obj, id, vp);
}
bool
js::Throw(JSContext* cx, jsid id, unsigned errorNumber)
{
MOZ_ASSERT(js_ErrorFormatString[errorNumber].argCount == 1);
RootedValue idVal(cx, IdToValue(id));
JSString* idstr = ValueToSource(cx, idVal);
if (!idstr)
return false;
JSAutoByteString bytes(cx, idstr);
if (!bytes)
return false;
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, errorNumber, bytes.ptr());
return false;
}
bool
js::Throw(JSContext* cx, JSObject* obj, unsigned errorNumber)
{
if (js_ErrorFormatString[errorNumber].argCount == 1) {
RootedValue val(cx, ObjectValue(*obj));
ReportValueErrorFlags(cx, JSREPORT_ERROR, errorNumber,
JSDVG_IGNORE_STACK, val, nullptr,
nullptr, nullptr);
} else {
MOZ_ASSERT(js_ErrorFormatString[errorNumber].argCount == 0);
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, errorNumber);
}
return false;
}
/*** PropertyDescriptor operations and DefineProperties ******************************************/
bool
CheckCallable(JSContext* cx, JSObject* obj, const char* fieldName)
{
if (obj && !obj->isCallable()) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_BAD_GET_SET_FIELD,
fieldName);
return false;
}
return true;
}
bool
js::ToPropertyDescriptor(JSContext* cx, HandleValue descval, bool checkAccessors,
MutableHandle<PropertyDescriptor> desc)
{
// step 2
RootedObject obj(cx, NonNullObject(cx, descval));
if (!obj)
return false;
// step 3
desc.clear();
bool found = false;
RootedId id(cx);
RootedValue v(cx);
unsigned attrs = 0;
// step 4
id = NameToId(cx->names().enumerable);
if (!GetPropertyIfPresent(cx, obj, id, &v, &found))
return false;
if (found) {
if (ToBoolean(v))
attrs |= JSPROP_ENUMERATE;
} else {
attrs |= JSPROP_IGNORE_ENUMERATE;
}
// step 5
id = NameToId(cx->names().configurable);
if (!GetPropertyIfPresent(cx, obj, id, &v, &found))
return false;
if (found) {
if (!ToBoolean(v))
attrs |= JSPROP_PERMANENT;
} else {
attrs |= JSPROP_IGNORE_PERMANENT;
}
// step 6
id = NameToId(cx->names().value);
if (!GetPropertyIfPresent(cx, obj, id, &v, &found))
return false;
if (found)
desc.value().set(v);
else
attrs |= JSPROP_IGNORE_VALUE;
// step 7
id = NameToId(cx->names().writable);
if (!GetPropertyIfPresent(cx, obj, id, &v, &found))
return false;
if (found) {
if (!ToBoolean(v))
attrs |= JSPROP_READONLY;
} else {
attrs |= JSPROP_IGNORE_READONLY;
}
// step 8
bool hasGetOrSet;
id = NameToId(cx->names().get);
if (!GetPropertyIfPresent(cx, obj, id, &v, &found))
return false;
hasGetOrSet = found;
if (found) {
if (v.isObject()) {
if (checkAccessors && !CheckCallable(cx, &v.toObject(), js_getter_str))
return false;
desc.setGetterObject(&v.toObject());
} else if (!v.isUndefined()) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_BAD_GET_SET_FIELD,
js_getter_str);
return false;
}
attrs |= JSPROP_GETTER | JSPROP_SHARED;
}
// step 9
id = NameToId(cx->names().set);
if (!GetPropertyIfPresent(cx, obj, id, &v, &found))
return false;
hasGetOrSet |= found;
if (found) {
if (v.isObject()) {
if (checkAccessors && !CheckCallable(cx, &v.toObject(), js_setter_str))
return false;
desc.setSetterObject(&v.toObject());
} else if (!v.isUndefined()) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_BAD_GET_SET_FIELD,
js_setter_str);
return false;
}
attrs |= JSPROP_SETTER | JSPROP_SHARED;
}
// step 10
if (hasGetOrSet) {
if (!(attrs & JSPROP_IGNORE_READONLY) || !(attrs & JSPROP_IGNORE_VALUE)) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_INVALID_DESCRIPTOR);
return false;
}
// By convention, these bits are not used on accessor descriptors.
attrs &= ~(JSPROP_IGNORE_READONLY | JSPROP_IGNORE_VALUE);
}
desc.setAttributes(attrs);
MOZ_ASSERT_IF(attrs & JSPROP_READONLY, !(attrs & (JSPROP_GETTER | JSPROP_SETTER)));
MOZ_ASSERT_IF(attrs & (JSPROP_GETTER | JSPROP_SETTER), attrs & JSPROP_SHARED);
return true;
}
bool
js::CheckPropertyDescriptorAccessors(JSContext* cx, Handle<PropertyDescriptor> desc)
{
if (desc.hasGetterObject()) {
if (!CheckCallable(cx, desc.getterObject(), js_getter_str))
return false;
}
if (desc.hasSetterObject()) {
if (!CheckCallable(cx, desc.setterObject(), js_setter_str))
return false;
}
return true;
}
void
js::CompletePropertyDescriptor(MutableHandle<PropertyDescriptor> desc)
{
desc.assertValid();
if (desc.isGenericDescriptor() || desc.isDataDescriptor()) {
if (!desc.hasWritable())
desc.attributesRef() |= JSPROP_READONLY;
desc.attributesRef() &= ~(JSPROP_IGNORE_READONLY | JSPROP_IGNORE_VALUE);
} else {
if (!desc.hasGetterObject())
desc.setGetterObject(nullptr);
if (!desc.hasSetterObject())
desc.setSetterObject(nullptr);
desc.attributesRef() |= JSPROP_GETTER | JSPROP_SETTER | JSPROP_SHARED;
}
if (!desc.hasConfigurable())
desc.attributesRef() |= JSPROP_PERMANENT;
desc.attributesRef() &= ~(JSPROP_IGNORE_PERMANENT | JSPROP_IGNORE_ENUMERATE);
desc.assertComplete();
}
bool
js::ReadPropertyDescriptors(JSContext* cx, HandleObject props, bool checkAccessors,
AutoIdVector* ids, MutableHandle<PropertyDescriptorVector> descs)
{
if (!GetPropertyKeys(cx, props, JSITER_OWNONLY | JSITER_SYMBOLS, ids))
return false;
RootedId id(cx);
for (size_t i = 0, len = ids->length(); i < len; i++) {
id = (*ids)[i];
Rooted<PropertyDescriptor> desc(cx);
RootedValue v(cx);
if (!GetProperty(cx, props, props, id, &v) ||
!ToPropertyDescriptor(cx, v, checkAccessors, &desc) ||
!descs.append(desc))
{
return false;
}
}
return true;
}
bool
js::DefineProperties(JSContext* cx, HandleObject obj, HandleObject props)
{
AutoIdVector ids(cx);
Rooted<PropertyDescriptorVector> descs(cx, PropertyDescriptorVector(cx));
if (!ReadPropertyDescriptors(cx, props, true, &ids, &descs))
return false;
for (size_t i = 0, len = ids.length(); i < len; i++) {
if (!DefineProperty(cx, obj, ids[i], descs[i]))
return false;
}
return true;
}
/*** Seal and freeze *****************************************************************************/
static unsigned
GetSealedOrFrozenAttributes(unsigned attrs, IntegrityLevel level)
{
/* Make all attributes permanent; if freezing, make data attributes read-only. */
if (level == IntegrityLevel::Frozen && !(attrs & (JSPROP_GETTER | JSPROP_SETTER)))
return JSPROP_PERMANENT | JSPROP_READONLY;
return JSPROP_PERMANENT;
}
/* ES6 draft rev 29 (6 Dec 2014) 7.3.13. */
bool
js::SetIntegrityLevel(JSContext* cx, HandleObject obj, IntegrityLevel level)
{
assertSameCompartment(cx, obj);
// Steps 3-5. (Steps 1-2 are redundant assertions.)
if (!PreventExtensions(cx, obj))
return false;
// Steps 6-7.
AutoIdVector keys(cx);
if (!GetPropertyKeys(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY | JSITER_SYMBOLS, &keys))
return false;
// PreventExtensions must sparsify dense objects, so we can assign to holes
// without checks.
MOZ_ASSERT_IF(obj->isNative(), obj->as<NativeObject>().getDenseCapacity() == 0);
// Steps 8-9, loosely interpreted.
if (obj->isNative() && !obj->as<NativeObject>().inDictionaryMode() && !IsAnyTypedArray(obj)) {
HandleNativeObject nobj = obj.as<NativeObject>();
// Seal/freeze non-dictionary objects by constructing a new shape
// hierarchy mirroring the original one, which can be shared if many
// objects with the same structure are sealed/frozen. If we use the
// generic path below then any non-empty object will be converted to
// dictionary mode.
RootedShape last(cx, EmptyShape::getInitialShape(cx, nobj->getClass(),
nobj->getTaggedProto(),
nobj->numFixedSlots(),
nobj->lastProperty()->getObjectFlags()));
if (!last)
return false;
// Get an in-order list of the shapes in this object.
Rooted<ShapeVector> shapes(cx, ShapeVector(cx));
for (Shape::Range<NoGC> r(nobj->lastProperty()); !r.empty(); r.popFront()) {
if (!shapes.append(&r.front()))
return false;
}
Reverse(shapes.begin(), shapes.end());
for (Shape* shape : shapes) {
Rooted<StackShape> child(cx, StackShape(shape));
child.setAttrs(child.attrs() | GetSealedOrFrozenAttributes(child.attrs(), level));
if (!JSID_IS_EMPTY(child.get().propid) && level == IntegrityLevel::Frozen)
MarkTypePropertyNonWritable(cx, nobj, child.get().propid);
last = cx->compartment()->propertyTree.getChild(cx, last, child);
if (!last)
return false;
}
MOZ_ASSERT(nobj->lastProperty()->slotSpan() == last->slotSpan());
JS_ALWAYS_TRUE(nobj->setLastProperty(cx, last));
// Ordinarily ArraySetLength handles this, but we're going behind its back
// right now, so we must do this manually.
//
// ArraySetLength also implements the capacity <= length invariant for
// arrays with non-writable length. We don't need to do anything special
// for that, because capacity was zeroed out by preventExtensions. (See
// the assertion about getDenseCapacity above.)
if (level == IntegrityLevel::Frozen && obj->is<ArrayObject>()) {
if (!obj->as<ArrayObject>().maybeCopyElementsForWrite(cx))
return false;
obj->as<ArrayObject>().getElementsHeader()->setNonwritableArrayLength();
}
} else {
RootedId id(cx);
Rooted<PropertyDescriptor> desc(cx);
const unsigned AllowConfigure = JSPROP_IGNORE_ENUMERATE | JSPROP_IGNORE_READONLY |
JSPROP_IGNORE_VALUE;
const unsigned AllowConfigureAndWritable = AllowConfigure & ~JSPROP_IGNORE_READONLY;
// 8.a/9.a. The two different loops are merged here.
for (size_t i = 0; i < keys.length(); i++) {
id = keys[i];
if (level == IntegrityLevel::Sealed) {
// 8.a.i.
desc.setAttributes(AllowConfigure | JSPROP_PERMANENT);
} else {
// 9.a.i-ii.
Rooted<PropertyDescriptor> currentDesc(cx);
if (!GetOwnPropertyDescriptor(cx, obj, id, &currentDesc))
return false;
// 9.a.iii.
if (!currentDesc.object())
continue;
// 9.a.iii.1-2
if (currentDesc.isAccessorDescriptor())
desc.setAttributes(AllowConfigure | JSPROP_PERMANENT);
else
desc.setAttributes(AllowConfigureAndWritable | JSPROP_PERMANENT | JSPROP_READONLY);
}
// 8.a.i-ii. / 9.a.iii.3-4
if (!DefineProperty(cx, obj, id, desc))
return false;
}
}
return true;
}
// ES6 draft rev33 (12 Feb 2015) 7.3.15
bool
js::TestIntegrityLevel(JSContext* cx, HandleObject obj, IntegrityLevel level, bool* result)
{
// Steps 3-6. (Steps 1-2 are redundant assertions.)
bool status;
if (!IsExtensible(cx, obj, &status))
return false;
if (status) {
*result = false;
return true;
}
// Steps 7-8.
AutoIdVector props(cx);
if (!GetPropertyKeys(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY | JSITER_SYMBOLS, &props))
return false;
// Step 9.
RootedId id(cx);
Rooted<PropertyDescriptor> desc(cx);
for (size_t i = 0, len = props.length(); i < len; i++) {
id = props[i];
// Steps 9.a-b.
if (!GetOwnPropertyDescriptor(cx, obj, id, &desc))
return false;
// Step 9.c.
if (!desc.object())
continue;
// Steps 9.c.i-ii.
if (desc.configurable() ||
(level == IntegrityLevel::Frozen && desc.isDataDescriptor() && desc.writable()))
{
*result = false;
return true;
}
}
// Step 10.
*result = true;
return true;
}
/* * */
/*
* Get the GC kind to use for scripted 'new' on the given class.
* FIXME bug 547327: estimate the size from the allocation site.
*/
static inline gc::AllocKind
NewObjectGCKind(const js::Class* clasp)
{
if (clasp == &ArrayObject::class_)
return gc::AllocKind::OBJECT8;
if (clasp == &JSFunction::class_)
return gc::AllocKind::OBJECT2;
return gc::AllocKind::OBJECT4;
}
static inline JSObject*
NewObject(ExclusiveContext* cx, HandleObjectGroup group, gc::AllocKind kind,
NewObjectKind newKind, uint32_t initialShapeFlags = 0)
{
const Class* clasp = group->clasp();
MOZ_ASSERT(clasp != &ArrayObject::class_);
MOZ_ASSERT_IF(clasp == &JSFunction::class_,
kind == AllocKind::FUNCTION || kind == AllocKind::FUNCTION_EXTENDED);
// For objects which can have fixed data following the object, only use
// enough fixed slots to cover the number of reserved slots in the object,
// regardless of the allocation kind specified.
size_t nfixed = ClassCanHaveFixedData(clasp)
? GetGCKindSlots(gc::GetGCObjectKind(clasp), clasp)
: GetGCKindSlots(kind, clasp);
RootedShape shape(cx, EmptyShape::getInitialShape(cx, clasp, group->proto(), nfixed,
initialShapeFlags));
if (!shape)
return nullptr;
gc::InitialHeap heap = GetInitialHeap(newKind, clasp);
JSObject* obj = JSObject::create(cx, kind, heap, shape, group);
if (!obj)
return nullptr;
if (newKind == SingletonObject) {
RootedObject nobj(cx, obj);
if (!JSObject::setSingleton(cx, nobj))
return nullptr;
obj = nobj;
}
probes::CreateObject(cx, obj);
return obj;
}
void
NewObjectCache::fillProto(EntryIndex entry, const Class* clasp, js::TaggedProto proto,
gc::AllocKind kind, NativeObject* obj)
{
MOZ_ASSERT_IF(proto.isObject(), !proto.toObject()->is<GlobalObject>());
MOZ_ASSERT(obj->getTaggedProto() == proto);
return fill(entry, clasp, proto.raw(), kind, obj);
}
bool
js::NewObjectWithTaggedProtoIsCachable(ExclusiveContext* cxArg, Handle<TaggedProto> proto,
NewObjectKind newKind, const Class* clasp)
{
return cxArg->isJSContext() &&
proto.isObject() &&
newKind == GenericObject &&
clasp->isNative() &&
!proto.toObject()->is<GlobalObject>();
}
JSObject*
js::NewObjectWithGivenTaggedProto(ExclusiveContext* cxArg, const Class* clasp,
Handle<TaggedProto> proto,
gc::AllocKind allocKind, NewObjectKind newKind,
uint32_t initialShapeFlags)
{
if (CanBeFinalizedInBackground(allocKind, clasp))
allocKind = GetBackgroundAllocKind(allocKind);
bool isCachable = NewObjectWithTaggedProtoIsCachable(cxArg, proto, newKind, clasp);
if (isCachable) {
JSContext* cx = cxArg->asJSContext();
JSRuntime* rt = cx->runtime();
NewObjectCache& cache = rt->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
if (cache.lookupProto(clasp, proto.toObject(), allocKind, &entry)) {
JSObject* obj = cache.newObjectFromHit(cx, entry, GetInitialHeap(newKind, clasp));
if (obj)
return obj;
}
}
RootedObjectGroup group(cxArg, ObjectGroup::defaultNewGroup(cxArg, clasp, proto, nullptr));
if (!group)
return nullptr;
RootedObject obj(cxArg, NewObject(cxArg, group, allocKind, newKind, initialShapeFlags));
if (!obj)
return nullptr;
if (isCachable && !obj->as<NativeObject>().hasDynamicSlots()) {
NewObjectCache& cache = cxArg->asJSContext()->runtime()->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
cache.lookupProto(clasp, proto.toObject(), allocKind, &entry);
cache.fillProto(entry, clasp, proto, allocKind, &obj->as<NativeObject>());
}
return obj;
}
static bool
NewObjectIsCachable(ExclusiveContext* cxArg, NewObjectKind newKind, const Class* clasp)
{
return cxArg->isJSContext() &&
newKind == GenericObject &&
clasp->isNative();
}
JSObject*
js::NewObjectWithClassProtoCommon(ExclusiveContext* cxArg, const Class* clasp,
HandleObject protoArg,
gc::AllocKind allocKind, NewObjectKind newKind)
{
if (protoArg) {
return NewObjectWithGivenTaggedProto(cxArg, clasp, AsTaggedProto(protoArg),
allocKind, newKind);
}
if (CanBeFinalizedInBackground(allocKind, clasp))
allocKind = GetBackgroundAllocKind(allocKind);
Handle<GlobalObject*> global = cxArg->global();
bool isCachable = NewObjectIsCachable(cxArg, newKind, clasp);
if (isCachable) {
JSContext* cx = cxArg->asJSContext();
JSRuntime* rt = cx->runtime();
NewObjectCache& cache = rt->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
if (cache.lookupGlobal(clasp, global, allocKind, &entry)) {
JSObject* obj = cache.newObjectFromHit(cx, entry, GetInitialHeap(newKind, clasp));
if (obj)
return obj;
}
}
/*
* Find the appropriate proto for clasp. Built-in classes have a cached
* proto on cx->global(); all others get %ObjectPrototype%.
*/
JSProtoKey protoKey = JSCLASS_CACHED_PROTO_KEY(clasp);
if (protoKey == JSProto_Null)
protoKey = JSProto_Object;
RootedObject proto(cxArg, protoArg);
if (!GetBuiltinPrototype(cxArg, protoKey, &proto))
return nullptr;
Rooted<TaggedProto> taggedProto(cxArg, TaggedProto(proto));
RootedObjectGroup group(cxArg, ObjectGroup::defaultNewGroup(cxArg, clasp, taggedProto));
if (!group)
return nullptr;
JSObject* obj = NewObject(cxArg, group, allocKind, newKind);
if (!obj)
return nullptr;
if (isCachable && !obj->as<NativeObject>().hasDynamicSlots()) {
NewObjectCache& cache = cxArg->asJSContext()->runtime()->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
cache.lookupGlobal(clasp, global, allocKind, &entry);
cache.fillGlobal(entry, clasp, global, allocKind,
&obj->as<NativeObject>());
}
return obj;
}
static bool
NewObjectWithGroupIsCachable(ExclusiveContext* cx, HandleObjectGroup group,
NewObjectKind newKind)
{
return group->proto().isObject() &&
newKind == GenericObject &&
group->clasp()->isNative() &&
(!group->newScript() || group->newScript()->analyzed()) &&
cx->isJSContext();
}
/*
* Create a plain object with the specified group. This bypasses getNewGroup to
* avoid losing creation site information for objects made by scripted 'new'.
*/
JSObject*
js::NewObjectWithGroupCommon(ExclusiveContext* cx, HandleObjectGroup group,
gc::AllocKind allocKind, NewObjectKind newKind)
{
MOZ_ASSERT(gc::IsObjectAllocKind(allocKind));
if (CanBeFinalizedInBackground(allocKind, group->clasp()))
allocKind = GetBackgroundAllocKind(allocKind);
bool isCachable = NewObjectWithGroupIsCachable(cx, group, newKind);
if (isCachable) {
NewObjectCache& cache = cx->asJSContext()->runtime()->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
if (cache.lookupGroup(group, allocKind, &entry)) {
JSObject* obj = cache.newObjectFromHit(cx->asJSContext(), entry,
GetInitialHeap(newKind, group->clasp()));
if (obj)
return obj;
}
}
JSObject* obj = NewObject(cx, group, allocKind, newKind);
if (!obj)
return nullptr;
if (isCachable && !obj->as<NativeObject>().hasDynamicSlots()) {
NewObjectCache& cache = cx->asJSContext()->runtime()->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
cache.lookupGroup(group, allocKind, &entry);
cache.fillGroup(entry, group, allocKind, &obj->as<NativeObject>());
}
return obj;
}
bool
js::NewObjectScriptedCall(JSContext* cx, MutableHandleObject pobj)
{
jsbytecode* pc;
RootedScript script(cx, cx->currentScript(&pc));
gc::AllocKind allocKind = NewObjectGCKind(&PlainObject::class_);
NewObjectKind newKind = GenericObject;
if (script && ObjectGroup::useSingletonForAllocationSite(script, pc, &PlainObject::class_))
newKind = SingletonObject;
RootedObject obj(cx, NewBuiltinClassInstance<PlainObject>(cx, allocKind, newKind));
if (!obj)
return false;
if (script) {
/* Try to specialize the group of the object to the scripted call site. */
if (!ObjectGroup::setAllocationSiteObjectGroup(cx, script, pc, obj, newKind == SingletonObject))
return false;
}
pobj.set(obj);
return true;
}
JSObject*
js::CreateThis(JSContext* cx, const Class* newclasp, HandleObject callee)
{
RootedObject proto(cx);
if (!GetPrototypeFromConstructor(cx, callee, &proto))
return nullptr;
gc::AllocKind kind = NewObjectGCKind(newclasp);
return NewObjectWithClassProto(cx, newclasp, proto, kind);
}
static inline JSObject*
CreateThisForFunctionWithGroup(JSContext* cx, HandleObjectGroup group,
NewObjectKind newKind)
{
if (group->maybeUnboxedLayout() && newKind != SingletonObject)
return UnboxedPlainObject::create(cx, group, newKind);
if (TypeNewScript* newScript = group->newScript()) {
if (newScript->analyzed()) {
// The definite properties analysis has been performed for this
// group, so get the shape and alloc kind to use from the
// TypeNewScript's template.
RootedPlainObject templateObject(cx, newScript->templateObject());
MOZ_ASSERT(templateObject->group() == group);
RootedPlainObject res(cx, CopyInitializerObject(cx, templateObject, newKind));
if (!res)
return nullptr;
if (newKind == SingletonObject) {
Rooted<TaggedProto> proto(cx, TaggedProto(templateObject->getProto()));
if (!res->splicePrototype(cx, &PlainObject::class_, proto))
return nullptr;
} else {
res->setGroup(group);
}
return res;
}
// The initial objects registered with a TypeNewScript can't be in the
// nursery.
if (newKind == GenericObject)
newKind = TenuredObject;
// Not enough objects with this group have been created yet, so make a
// plain object and register it with the group. Use the maximum number
// of fixed slots, as is also required by the TypeNewScript.
gc::AllocKind allocKind = GuessObjectGCKind(NativeObject::MAX_FIXED_SLOTS);
PlainObject* res = NewObjectWithGroup<PlainObject>(cx, group, allocKind, newKind);
if (!res)
return nullptr;
// Make sure group->newScript is still there.
if (newKind != SingletonObject && group->newScript())
group->newScript()->registerNewObject(res);
return res;
}
gc::AllocKind allocKind = NewObjectGCKind(&PlainObject::class_);
if (newKind == SingletonObject) {
Rooted<TaggedProto> protoRoot(cx, group->proto());
return NewObjectWithGivenTaggedProto(cx, &PlainObject::class_, protoRoot, allocKind, newKind);
}
return NewObjectWithGroup<PlainObject>(cx, group, allocKind, newKind);
}
JSObject*
js::CreateThisForFunctionWithProto(JSContext* cx, HandleObject callee, HandleObject newTarget,
HandleObject proto, NewObjectKind newKind /* = GenericObject */)
{
RootedObject res(cx);
if (proto) {
RootedObjectGroup group(cx, ObjectGroup::defaultNewGroup(cx, nullptr, TaggedProto(proto),
newTarget));
if (!group)
return nullptr;
if (group->newScript() && !group->newScript()->analyzed()) {
bool regenerate;
if (!group->newScript()->maybeAnalyze(cx, group, &regenerate))
return nullptr;
if (regenerate) {
// The script was analyzed successfully and may have changed
// the new type table, so refetch the group.
group = ObjectGroup::defaultNewGroup(cx, nullptr, TaggedProto(proto),
newTarget);
MOZ_ASSERT(group && group->newScript());
}
}
res = CreateThisForFunctionWithGroup(cx, group, newKind);
} else {
res = NewBuiltinClassInstance<PlainObject>(cx, newKind);
}
if (res) {
JSScript* script = callee->as<JSFunction>().getOrCreateScript(cx);
if (!script)
return nullptr;
TypeScript::SetThis(cx, script, TypeSet::ObjectType(res));
}
return res;
}
bool
js::GetPrototypeFromConstructor(JSContext* cx, HandleObject newTarget, MutableHandleObject proto)
{
RootedValue protov(cx);
if (!GetProperty(cx, newTarget, newTarget, cx->names().prototype, &protov))
return false;
proto.set(protov.isObject() ? &protov.toObject() : nullptr);
return true;
}
bool
js::GetPrototypeFromCallableConstructor(JSContext* cx, const CallArgs& args, MutableHandleObject proto)
{
RootedObject newTarget(cx);
if (args.isConstructing())
newTarget = &args.newTarget().toObject();
else
newTarget = &args.callee();
return GetPrototypeFromConstructor(cx, newTarget, proto);
}
JSObject*
js::CreateThisForFunction(JSContext* cx, HandleObject callee, HandleObject newTarget,
NewObjectKind newKind)
{
RootedObject proto(cx);
if (!GetPrototypeFromConstructor(cx, newTarget, &proto))
return nullptr;
JSObject* obj = CreateThisForFunctionWithProto(cx, callee, newTarget, proto, newKind);
if (obj && newKind == SingletonObject) {
RootedPlainObject nobj(cx, &obj->as<PlainObject>());
/* Reshape the singleton before passing it as the 'this' value. */
NativeObject::clear(cx, nobj);
JSScript* calleeScript = callee->as<JSFunction>().nonLazyScript();
TypeScript::SetThis(cx, calleeScript, TypeSet::ObjectType(nobj));
return nobj;
}
return obj;
}
/* static */ bool
JSObject::nonNativeSetProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v,
HandleValue receiver, ObjectOpResult& result)
{
RootedValue value(cx, v);
if (MOZ_UNLIKELY(obj->watched())) {
WatchpointMap* wpmap = cx->compartment()->watchpointMap;
if (wpmap && !wpmap->triggerWatchpoint(cx, obj, id, &value))
return false;
}
return obj->getOps()->setProperty(cx, obj, id, value, receiver, result);
}
/* static */ bool
JSObject::nonNativeSetElement(JSContext* cx, HandleObject obj, uint32_t index, HandleValue v,
HandleValue receiver, ObjectOpResult& result)
{
RootedId id(cx);
if (!IndexToId(cx, index, &id))
return false;
return nonNativeSetProperty(cx, obj, id, v, receiver, result);
}
JS_FRIEND_API(bool)
JS_CopyPropertyFrom(JSContext* cx, HandleId id, HandleObject target,
HandleObject obj, PropertyCopyBehavior copyBehavior)
{
// |obj| and |cx| are generally not same-compartment with |target| here.
assertSameCompartment(cx, obj, id);
Rooted<JSPropertyDescriptor> desc(cx);
if (!GetOwnPropertyDescriptor(cx, obj, id, &desc))
return false;
MOZ_ASSERT(desc.object());
// Silently skip JSGetterOp/JSSetterOp-implemented accessors.
if (desc.getter() && !desc.hasGetterObject())
return true;
if (desc.setter() && !desc.hasSetterObject())
return true;
if (copyBehavior == MakeNonConfigurableIntoConfigurable) {
// Mask off the JSPROP_PERMANENT bit.
desc.attributesRef() &= ~JSPROP_PERMANENT;
}
JSAutoCompartment ac(cx, target);
RootedId wrappedId(cx, id);
if (!cx->compartment()->wrap(cx, &desc))
return false;
return DefineProperty(cx, target, wrappedId, desc);
}
JS_FRIEND_API(bool)
JS_CopyPropertiesFrom(JSContext* cx, HandleObject target, HandleObject obj)
{
JSAutoCompartment ac(cx, obj);
AutoIdVector props(cx);
if (!GetPropertyKeys(cx, obj, JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS, &props))
return false;
for (size_t i = 0; i < props.length(); ++i) {
if (!JS_CopyPropertyFrom(cx, props[i], target, obj))
return false;
}
return true;
}
static bool
CopyProxyObject(JSContext* cx, Handle<ProxyObject*> from, Handle<ProxyObject*> to)
{
MOZ_ASSERT(from->getClass() == to->getClass());
if (from->is<WrapperObject>() &&
(Wrapper::wrapperHandler(from)->flags() &
Wrapper::CROSS_COMPARTMENT))
{
to->setCrossCompartmentPrivate(GetProxyPrivate(from));
} else {
RootedValue v(cx, GetProxyPrivate(from));
if (!cx->compartment()->wrap(cx, &v))
return false;
to->setSameCompartmentPrivate(v);
}
RootedValue v(cx);
for (size_t n = 0; n < PROXY_EXTRA_SLOTS; n++) {
v = GetProxyExtra(from, n);
if (!cx->compartment()->wrap(cx, &v))
return false;
SetProxyExtra(to, n, v);
}
return true;
}
JSObject*
js::CloneObject(JSContext* cx, HandleObject obj, Handle<js::TaggedProto> proto)
{
if (!obj->isNative() && !obj->is<ProxyObject>()) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr,
JSMSG_CANT_CLONE_OBJECT);
return nullptr;
}
RootedObject clone(cx);
if (obj->isNative()) {
clone = NewObjectWithGivenTaggedProto(cx, obj->getClass(), proto);
if (!clone)
return nullptr;
if (clone->is<JSFunction>() && (obj->compartment() != clone->compartment())) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr,
JSMSG_CANT_CLONE_OBJECT);
return nullptr;
}
if (obj->as<NativeObject>().hasPrivate())
clone->as<NativeObject>().setPrivate(obj->as<NativeObject>().getPrivate());
} else {
ProxyOptions options;
options.setClass(obj->getClass());
clone = ProxyObject::New(cx, GetProxyHandler(obj), JS::NullHandleValue, proto, options);
if (!clone)
return nullptr;
if (!CopyProxyObject(cx, obj.as<ProxyObject>(), clone.as<ProxyObject>()))
return nullptr;
}
return clone;
}
static bool
GetScriptArrayObjectElements(JSContext* cx, HandleObject obj, AutoValueVector& values)
{
MOZ_ASSERT(!obj->isSingleton());
MOZ_ASSERT(obj->is<ArrayObject>() || obj->is<UnboxedArrayObject>());
size_t length = GetAnyBoxedOrUnboxedArrayLength(obj);
if (!values.appendN(MagicValue(JS_ELEMENTS_HOLE), length))
return false;
if (obj->nonProxyIsExtensible()) {
MOZ_ASSERT_IF(obj->is<ArrayObject>(), obj->as<ArrayObject>().slotSpan() == 0);
size_t initlen = GetAnyBoxedOrUnboxedInitializedLength(obj);
for (size_t i = 0; i < initlen; i++)
values[i].set(GetAnyBoxedOrUnboxedDenseElement(obj, i));
} else {
// Call site objects are frozen before they escape to script, which
// converts their dense elements into data properties.
ArrayObject* aobj = &obj->as<ArrayObject>();
for (Shape::Range<NoGC> r(aobj->lastProperty()); !r.empty(); r.popFront()) {
Shape& shape = r.front();
if (shape.propid() == NameToId(cx->names().length))
continue;
MOZ_ASSERT(shape.isDataDescriptor());
// The 'raw' property is added before freezing call site objects.
// After an XDR or deep clone the script object will no longer be
// frozen, and the two objects will be connected again the first
// time the JSOP_CALLSITEOBJ executes.
if (shape.propid() == NameToId(cx->names().raw))
continue;
uint32_t index = JSID_TO_INT(shape.propid());
values[index].set(aobj->getSlot(shape.slot()));
}
}
return true;
}
static bool
GetScriptPlainObjectProperties(JSContext* cx, HandleObject obj,
MutableHandle<IdValueVector> properties)
{
if (obj->is<PlainObject>()) {
PlainObject* nobj = &obj->as<PlainObject>();
if (!properties.appendN(IdValuePair(), nobj->slotSpan()))
return false;
for (Shape::Range<NoGC> r(nobj->lastProperty()); !r.empty(); r.popFront()) {
Shape& shape = r.front();
MOZ_ASSERT(shape.isDataDescriptor());
uint32_t slot = shape.slot();
properties[slot].get().id = shape.propid();
properties[slot].get().value = nobj->getSlot(slot);
}
for (size_t i = 0; i < nobj->getDenseInitializedLength(); i++) {
Value v = nobj->getDenseElement(i);
if (!v.isMagic(JS_ELEMENTS_HOLE) && !properties.append(IdValuePair(INT_TO_JSID(i), v)))
return false;
}
return true;
}
if (obj->is<UnboxedPlainObject>()) {
UnboxedPlainObject* nobj = &obj->as<UnboxedPlainObject>();
const UnboxedLayout& layout = nobj->layout();
if (!properties.appendN(IdValuePair(), layout.properties().length()))
return false;
for (size_t i = 0; i < layout.properties().length(); i++) {
const UnboxedLayout::Property& property = layout.properties()[i];
properties[i].get().id = NameToId(property.name);
properties[i].get().value = nobj->getValue(property);
}
return true;
}
MOZ_CRASH("Bad object kind");
}
static bool
DeepCloneValue(JSContext* cx, Value* vp, NewObjectKind newKind)
{
if (vp->isObject()) {
RootedObject obj(cx, &vp->toObject());
obj = DeepCloneObjectLiteral(cx, obj, newKind);
if (!obj)
return false;
vp->setObject(*obj);
}
return true;
}
JSObject*
js::DeepCloneObjectLiteral(JSContext* cx, HandleObject obj, NewObjectKind newKind)
{
/* NB: Keep this in sync with XDRObjectLiteral. */
MOZ_ASSERT_IF(obj->isSingleton(),
JS::CompartmentOptionsRef(cx).getSingletonsAsTemplates());
MOZ_ASSERT(obj->is<PlainObject>() || obj->is<UnboxedPlainObject>() ||
obj->is<ArrayObject>() || obj->is<UnboxedArrayObject>());
MOZ_ASSERT(newKind != SingletonObject);
if (obj->is<ArrayObject>() || obj->is<UnboxedArrayObject>()) {
AutoValueVector values(cx);
if (!GetScriptArrayObjectElements(cx, obj, values))
return nullptr;
// Deep clone any elements.
for (uint32_t i = 0; i < values.length(); ++i) {
if (!DeepCloneValue(cx, values[i].address(), newKind))
return nullptr;
}
ObjectGroup::NewArrayKind arrayKind = ObjectGroup::NewArrayKind::Normal;
if (obj->is<ArrayObject>() && obj->as<ArrayObject>().denseElementsAreCopyOnWrite())
arrayKind = ObjectGroup::NewArrayKind::CopyOnWrite;
return ObjectGroup::newArrayObject(cx, values.begin(), values.length(), newKind,
arrayKind);
}
Rooted<IdValueVector> properties(cx, IdValueVector(cx));
if (!GetScriptPlainObjectProperties(cx, obj, &properties))
return nullptr;
for (size_t i = 0; i < properties.length(); i++) {
if (!DeepCloneValue(cx, &properties[i].get().value, newKind))
return nullptr;
}
if (obj->isSingleton())
newKind = SingletonObject;
return ObjectGroup::newPlainObject(cx, properties.begin(), properties.length(), newKind);
}
static bool
InitializePropertiesFromCompatibleNativeObject(JSContext* cx,
HandleNativeObject dst,
HandleNativeObject src)
{
assertSameCompartment(cx, src, dst);
MOZ_ASSERT(src->getClass() == dst->getClass());
MOZ_ASSERT(dst->lastProperty()->getObjectFlags() == 0);
MOZ_ASSERT(!src->isSingleton());
MOZ_ASSERT(src->numFixedSlots() == dst->numFixedSlots());
if (!dst->ensureElements(cx, src->getDenseInitializedLength()))
return false;
uint32_t initialized = src->getDenseInitializedLength();
for (uint32_t i = 0; i < initialized; ++i) {
dst->setDenseInitializedLength(i + 1);
dst->initDenseElement(i, src->getDenseElement(i));
}
MOZ_ASSERT(!src->hasPrivate());
RootedShape shape(cx);
if (src->getProto() == dst->getProto()) {
shape = src->lastProperty();
} else {
// We need to generate a new shape for dst that has dst's proto but all
// the property information from src. Note that we asserted above that
// dst's object flags are 0.
shape = EmptyShape::getInitialShape(cx, dst->getClass(), dst->getTaggedProto(),
dst->numFixedSlots(), 0);
if (!shape)
return false;
// Get an in-order list of the shapes in the src object.
Rooted<ShapeVector> shapes(cx, ShapeVector(cx));
for (Shape::Range<NoGC> r(src->lastProperty()); !r.empty(); r.popFront()) {
if (!shapes.append(&r.front()))
return false;
}
Reverse(shapes.begin(), shapes.end());
for (Shape* shape : shapes) {
Rooted<StackShape> child(cx, StackShape(shape));
shape = cx->compartment()->propertyTree.getChild(cx, shape, child);
if (!shape)
return false;
}
}
size_t span = shape->slotSpan();
if (!dst->setLastProperty(cx, shape))
return false;
for (size_t i = JSCLASS_RESERVED_SLOTS(src->getClass()); i < span; i++)
dst->setSlot(i, src->getSlot(i));
return true;
}
JS_FRIEND_API(bool)
JS_InitializePropertiesFromCompatibleNativeObject(JSContext* cx,
HandleObject dst,
HandleObject src)
{
return InitializePropertiesFromCompatibleNativeObject(cx,
dst.as<NativeObject>(),
src.as<NativeObject>());
}
template<XDRMode mode>
bool
js::XDRObjectLiteral(XDRState<mode>* xdr, MutableHandleObject obj)
{
/* NB: Keep this in sync with DeepCloneObjectLiteral. */
JSContext* cx = xdr->cx();
MOZ_ASSERT_IF(mode == XDR_ENCODE && obj->isSingleton(),
JS::CompartmentOptionsRef(cx).getSingletonsAsTemplates());
// Distinguish between objects and array classes.
uint32_t isArray = 0;
{
if (mode == XDR_ENCODE) {
MOZ_ASSERT(obj->is<PlainObject>() ||
obj->is<UnboxedPlainObject>() ||
obj->is<ArrayObject>() ||
obj->is<UnboxedArrayObject>());
isArray = (obj->is<ArrayObject>() || obj->is<UnboxedArrayObject>()) ? 1 : 0;
}
if (!xdr->codeUint32(&isArray))
return false;
}
RootedValue tmpValue(cx), tmpIdValue(cx);
RootedId tmpId(cx);
if (isArray) {
AutoValueVector values(cx);
if (mode == XDR_ENCODE && !GetScriptArrayObjectElements(cx, obj, values))
return false;
uint32_t initialized;
if (mode == XDR_ENCODE)
initialized = values.length();
if (!xdr->codeUint32(&initialized))
return false;
if (mode == XDR_DECODE && !values.appendN(MagicValue(JS_ELEMENTS_HOLE), initialized))
return false;
// Recursively copy dense elements.
for (unsigned i = 0; i < initialized; i++) {
if (!xdr->codeConstValue(values[i]))
return false;
}
uint32_t copyOnWrite;
if (mode == XDR_ENCODE)
copyOnWrite = obj->is<ArrayObject>() &&
obj->as<ArrayObject>().denseElementsAreCopyOnWrite();
if (!xdr->codeUint32(&copyOnWrite))
return false;
if (mode == XDR_DECODE) {
ObjectGroup::NewArrayKind arrayKind = copyOnWrite
? ObjectGroup::NewArrayKind::CopyOnWrite
: ObjectGroup::NewArrayKind::Normal;
obj.set(ObjectGroup::newArrayObject(cx, values.begin(), values.length(),
TenuredObject, arrayKind));
if (!obj)
return false;
}
return true;
}
// Code the properties in the object.
Rooted<IdValueVector> properties(cx, IdValueVector(cx));
if (mode == XDR_ENCODE && !GetScriptPlainObjectProperties(cx, obj, &properties))
return false;
uint32_t nproperties = properties.length();
if (!xdr->codeUint32(&nproperties))
return false;
if (mode == XDR_DECODE && !properties.appendN(IdValuePair(), nproperties))
return false;
for (size_t i = 0; i < nproperties; i++) {
if (mode == XDR_ENCODE) {
tmpIdValue = IdToValue(properties[i].get().id);
tmpValue = properties[i].get().value;
}
if (!xdr->codeConstValue(&tmpIdValue) || !xdr->codeConstValue(&tmpValue))
return false;
if (mode == XDR_DECODE) {
if (!ValueToId<CanGC>(cx, tmpIdValue, &tmpId))
return false;
properties[i].get().id = tmpId;
properties[i].get().value = tmpValue;
}
}
// Code whether the object is a singleton.
uint32_t isSingleton;
if (mode == XDR_ENCODE)
isSingleton = obj->isSingleton() ? 1 : 0;
if (!xdr->codeUint32(&isSingleton))
return false;
if (mode == XDR_DECODE) {
NewObjectKind newKind = isSingleton ? SingletonObject : TenuredObject;
obj.set(ObjectGroup::newPlainObject(cx, properties.begin(), properties.length(), newKind));
if (!obj)
return false;
}
return true;
}
template bool
js::XDRObjectLiteral(XDRState<XDR_ENCODE>* xdr, MutableHandleObject obj);
template bool
js::XDRObjectLiteral(XDRState<XDR_DECODE>* xdr, MutableHandleObject obj);
bool
NativeObject::fillInAfterSwap(JSContext* cx, const Vector<Value>& values, void* priv)
{
// This object has just been swapped with some other object, and its shape
// no longer reflects its allocated size. Correct this information and
// fill the slots in with the specified values.
MOZ_ASSERT(slotSpan() == values.length());
// Make sure the shape's numFixedSlots() is correct.
size_t nfixed = gc::GetGCKindSlots(asTenured().getAllocKind(), getClass());
if (nfixed != shape_->numFixedSlots()) {
if (!generateOwnShape(cx))
return false;
shape_->setNumFixedSlots(nfixed);
}
if (hasPrivate())
setPrivate(priv);
else
MOZ_ASSERT(!priv);
if (slots_) {
js_free(slots_);
slots_ = nullptr;
}
if (size_t ndynamic = dynamicSlotsCount(nfixed, values.length(), getClass())) {
slots_ = cx->zone()->pod_malloc<HeapSlot>(ndynamic);
if (!slots_)
return false;
Debug_SetSlotRangeToCrashOnTouch(slots_, ndynamic);
}
initSlotRange(0, values.begin(), values.length());
return true;
}
void
JSObject::fixDictionaryShapeAfterSwap()
{
// Dictionary shapes can point back to their containing objects, so after
// swapping the guts of those objects fix the pointers up.
if (isNative() && as<NativeObject>().inDictionaryMode())
as<NativeObject>().shape_->listp = &as<NativeObject>().shape_;
}
/* Use this method with extreme caution. It trades the guts of two objects. */
bool
JSObject::swap(JSContext* cx, HandleObject a, HandleObject b)
{
// Ensure swap doesn't cause a finalizer to not be run.
MOZ_ASSERT(IsBackgroundFinalized(a->asTenured().getAllocKind()) ==
IsBackgroundFinalized(b->asTenured().getAllocKind()));
MOZ_ASSERT(a->compartment() == b->compartment());
AutoEnterOOMUnsafeRegion oomUnsafe;
AutoCompartment ac(cx, a);
if (!a->getGroup(cx))
oomUnsafe.crash("JSObject::swap");
if (!b->getGroup(cx))
oomUnsafe.crash("JSObject::swap");
/*
* Neither object may be in the nursery, but ensure we update any embedded
* nursery pointers in either object.
*/
MOZ_ASSERT(!IsInsideNursery(a) && !IsInsideNursery(b));
cx->runtime()->gc.storeBuffer.putWholeCell(a);
cx->runtime()->gc.storeBuffer.putWholeCell(b);
unsigned r = NotifyGCPreSwap(a, b);
// Do the fundamental swapping of the contents of two objects.
MOZ_ASSERT(a->compartment() == b->compartment());
MOZ_ASSERT(a->is<JSFunction>() == b->is<JSFunction>());
// Don't try to swap functions with different sizes.
MOZ_ASSERT_IF(a->is<JSFunction>(), a->tenuredSizeOfThis() == b->tenuredSizeOfThis());
// Watch for oddball objects that have special organizational issues and
// can't be swapped.
MOZ_ASSERT(!a->is<RegExpObject>() && !b->is<RegExpObject>());
MOZ_ASSERT(!a->is<ArrayObject>() && !b->is<ArrayObject>());
MOZ_ASSERT(!a->is<ArrayBufferObject>() && !b->is<ArrayBufferObject>());
MOZ_ASSERT(!a->is<TypedArrayObject>() && !b->is<TypedArrayObject>());
MOZ_ASSERT(!a->is<TypedObject>() && !b->is<TypedObject>());
if (a->tenuredSizeOfThis() == b->tenuredSizeOfThis()) {
// When both objects are the same size, just do a plain swap of their
// contents.
size_t size = a->tenuredSizeOfThis();
char tmp[mozilla::tl::Max<sizeof(JSFunction), sizeof(JSObject_Slots16)>::value];
MOZ_ASSERT(size <= sizeof(tmp));
js_memcpy(tmp, a, size);
js_memcpy(a, b, size);
js_memcpy(b, tmp, size);
a->fixDictionaryShapeAfterSwap();
b->fixDictionaryShapeAfterSwap();
} else {
// Avoid GC in here to avoid confusing the tracing code with our
// intermediate state.
AutoSuppressGC suppress(cx);
// When the objects have different sizes, they will have different
// numbers of fixed slots before and after the swap, so the slots for
// native objects will need to be rearranged.
NativeObject* na = a->isNative() ? &a->as<NativeObject>() : nullptr;
NativeObject* nb = b->isNative() ? &b->as<NativeObject>() : nullptr;
// Remember the original values from the objects.
Vector<Value> avals(cx);
void* apriv = nullptr;
if (na) {
apriv = na->hasPrivate() ? na->getPrivate() : nullptr;
for (size_t i = 0; i < na->slotSpan(); i++) {
if (!avals.append(na->getSlot(i)))
oomUnsafe.crash("JSObject::swap");
}
}
Vector<Value> bvals(cx);
void* bpriv = nullptr;
if (nb) {
bpriv = nb->hasPrivate() ? nb->getPrivate() : nullptr;
for (size_t i = 0; i < nb->slotSpan(); i++) {
if (!bvals.append(nb->getSlot(i)))
oomUnsafe.crash("JSObject::swap");
}
}
// Swap the main fields of the objects, whether they are native objects or proxies.
char tmp[sizeof(JSObject_Slots0)];
js_memcpy(&tmp, a, sizeof tmp);
js_memcpy(a, b, sizeof tmp);
js_memcpy(b, &tmp, sizeof tmp);
a->fixDictionaryShapeAfterSwap();
b->fixDictionaryShapeAfterSwap();
if (na && !b->as<NativeObject>().fillInAfterSwap(cx, avals, apriv))
oomUnsafe.crash("fillInAfterSwap");
if (nb && !a->as<NativeObject>().fillInAfterSwap(cx, bvals, bpriv))
oomUnsafe.crash("fillInAfterSwap");
}
// Swapping the contents of two objects invalidates type sets which contain
// either of the objects, so mark all such sets as unknown.
MarkObjectGroupUnknownProperties(cx, a->group());
MarkObjectGroupUnknownProperties(cx, b->group());
/*
* We need a write barrier here. If |a| was marked and |b| was not, then
* after the swap, |b|'s guts would never be marked. The write barrier
* solves this.
*
* Normally write barriers happen before the write. However, that's not
* necessary here because nothing is being destroyed. We're just swapping.
*/
JS::Zone* zone = a->zone();
if (zone->needsIncrementalBarrier()) {
a->traceChildren(zone->barrierTracer());
b->traceChildren(zone->barrierTracer());
}
NotifyGCPostSwap(a, b, r);
return true;
}
static bool
DefineStandardSlot(JSContext* cx, HandleObject obj, JSProtoKey key, JSAtom* atom,
HandleValue v, uint32_t attrs, bool& named)
{
RootedId id(cx, AtomToId(atom));
if (key != JSProto_Null) {
/*
* Initializing an actual standard class on a global object. If the
* property is not yet present, force it into a new one bound to a
* reserved slot. Otherwise, go through the normal property path.
*/
Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
if (!global->lookup(cx, id)) {
global->setConstructorPropertySlot(key, v);
uint32_t slot = GlobalObject::constructorPropertySlot(key);
if (!NativeObject::addProperty(cx, global, id, nullptr, nullptr, slot, attrs, 0))
return false;
named = true;
return true;
}
}
named = DefineProperty(cx, obj, id, v, nullptr, nullptr, attrs);
return named;
}
static void
SetClassObject(JSObject* obj, JSProtoKey key, JSObject* cobj, JSObject* proto)
{
if (!obj->is<GlobalObject>())
return;
obj->as<GlobalObject>().setConstructor(key, ObjectOrNullValue(cobj));
obj->as<GlobalObject>().setPrototype(key, ObjectOrNullValue(proto));
}
static void
ClearClassObject(JSObject* obj, JSProtoKey key)
{
if (!obj->is<GlobalObject>())
return;
obj->as<GlobalObject>().setConstructor(key, UndefinedValue());
obj->as<GlobalObject>().setPrototype(key, UndefinedValue());
}
static NativeObject*
DefineConstructorAndPrototype(JSContext* cx, HandleObject obj, JSProtoKey key, HandleAtom atom,
HandleObject protoProto, const Class* clasp,
Native constructor, unsigned nargs,
const JSPropertySpec* ps, const JSFunctionSpec* fs,
const JSPropertySpec* static_ps, const JSFunctionSpec* static_fs,
NativeObject** ctorp, AllocKind ctorKind)
{
/*
* Create a prototype object for this class.
*
* FIXME: lazy standard (built-in) class initialization and even older
* eager boostrapping code rely on all of these properties:
*
* 1. NewObject attempting to compute a default prototype object when
* passed null for proto; and
*
* 2. NewObject tolerating no default prototype (null proto slot value)
* due to this js::InitClass call coming from js::InitFunctionClass on an
* otherwise-uninitialized global.
*
* 3. NewObject allocating a JSFunction-sized GC-thing when clasp is
* &JSFunction::class_, not a JSObject-sized (smaller) GC-thing.
*
* The JS_NewObjectForGivenProto and JS_NewObject APIs also allow clasp to
* be &JSFunction::class_ (we could break compatibility easily). But
* fixing (3) is not enough without addressing the bootstrapping dependency
* on (1) and (2).
*/
/*
* Create the prototype object. (GlobalObject::createBlankPrototype isn't
* used because it won't let us use protoProto as the proto.
*/
RootedNativeObject proto(cx, NewNativeObjectWithClassProto(cx, clasp, protoProto, SingletonObject));
if (!proto)
return nullptr;
/* After this point, control must exit via label bad or out. */
RootedNativeObject ctor(cx);
bool named = false;
bool cached = false;
if (!constructor) {
/*
* Lacking a constructor, name the prototype (e.g., Math) unless this
* class (a) is anonymous, i.e. for internal use only; (b) the class
* of obj (the global object) is has a reserved slot indexed by key;
* and (c) key is not the null key.
*/
if (!(clasp->flags & JSCLASS_IS_ANONYMOUS) || !obj->is<GlobalObject>() ||
key == JSProto_Null)
{
uint32_t attrs = (clasp->flags & JSCLASS_IS_ANONYMOUS)
? JSPROP_READONLY | JSPROP_PERMANENT
: 0;
RootedValue value(cx, ObjectValue(*proto));
if (!DefineStandardSlot(cx, obj, key, atom, value, attrs, named))
goto bad;
}
ctor = proto;
} else {
RootedFunction fun(cx, NewNativeConstructor(cx, constructor, nargs, atom, ctorKind));
if (!fun)
goto bad;
/*
* Set the class object early for standard class constructors. Type
* inference may need to access these, and js::GetBuiltinPrototype will
* fail if it tries to do a reentrant reconstruction of the class.
*/
if (key != JSProto_Null) {
SetClassObject(obj, key, fun, proto);
cached = true;
}
RootedValue value(cx, ObjectValue(*fun));
if (!DefineStandardSlot(cx, obj, key, atom, value, 0, named))
goto bad;
/*
* Optionally construct the prototype object, before the class has
* been fully initialized. Allow the ctor to replace proto with a
* different object, as is done for operator new.
*/
ctor = fun;
if (!LinkConstructorAndPrototype(cx, ctor, proto))
goto bad;
/* Bootstrap Function.prototype (see also JS_InitStandardClasses). */
Rooted<TaggedProto> tagged(cx, TaggedProto(proto));
if (ctor->getClass() == clasp && !ctor->splicePrototype(cx, clasp, tagged))
goto bad;
}
if (!DefinePropertiesAndFunctions(cx, proto, ps, fs) ||
(ctor != proto && !DefinePropertiesAndFunctions(cx, ctor, static_ps, static_fs)))
{
goto bad;
}
/* If this is a standard class, cache its prototype. */
if (!cached && key != JSProto_Null)
SetClassObject(obj, key, ctor, proto);
if (ctorp)
*ctorp = ctor;
return proto;
bad:
if (named) {
ObjectOpResult ignored;
RootedId id(cx, AtomToId(atom));
// XXX FIXME - absurd to call this here; instead define the property last.
DeleteProperty(cx, obj, id, ignored);
}
if (cached)
ClearClassObject(obj, key);
return nullptr;
}
NativeObject*
js::InitClass(JSContext* cx, HandleObject obj, HandleObject protoProto_,
const Class* clasp, Native constructor, unsigned nargs,
const JSPropertySpec* ps, const JSFunctionSpec* fs,
const JSPropertySpec* static_ps, const JSFunctionSpec* static_fs,
NativeObject** ctorp, AllocKind ctorKind)
{
RootedObject protoProto(cx, protoProto_);
/* Check function pointer members. */
MOZ_ASSERT(clasp->getProperty != JS_PropertyStub);
MOZ_ASSERT(clasp->setProperty != JS_StrictPropertyStub);
RootedAtom atom(cx, Atomize(cx, clasp->name, strlen(clasp->name)));
if (!atom)
return nullptr;
/*
* All instances of the class will inherit properties from the prototype
* object we are about to create (in DefineConstructorAndPrototype), which
* in turn will inherit from protoProto.
*
* When initializing a standard class (other than Object), if protoProto is
* null, default to Object.prototype. The engine's internal uses of
* js::InitClass depend on this nicety.
*/
JSProtoKey key = JSCLASS_CACHED_PROTO_KEY(clasp);
if (key != JSProto_Null &&
!protoProto &&
!GetBuiltinPrototype(cx, JSProto_Object, &protoProto))
{
return nullptr;
}
return DefineConstructorAndPrototype(cx, obj, key, atom, protoProto, clasp, constructor, nargs,
ps, fs, static_ps, static_fs, ctorp, ctorKind);
}
void
JSObject::fixupAfterMovingGC()
{
// For copy-on-write objects that don't own their elements, fix up the
// elements pointer if it points to inline elements in the owning object.
if (is<NativeObject>()) {
NativeObject& obj = as<NativeObject>();
if (obj.denseElementsAreCopyOnWrite()) {
NativeObject* owner = MaybeForwarded(obj.getElementsHeader()->ownerObject().get());
if (owner != &obj && owner->hasFixedElements())
obj.elements_ = owner->getElementsHeader()->elements();
MOZ_ASSERT(!IsForwarded(obj.getElementsHeader()->ownerObject().get()));
}
}
}
bool
js::SetClassAndProto(JSContext* cx, HandleObject obj,
const Class* clasp, Handle<js::TaggedProto> proto)
{
// Regenerate the object's shape. If the object is a proto (isDelegate()),
// we also need to regenerate shapes for all of the objects along the old
// prototype chain, in case any entries were filled by looking up through
// obj. Stop when a non-native object is found, prototype lookups will not
// be cached across these.
//
// How this shape change is done is very delicate; the change can be made
// either by marking the object's prototype as uncacheable (such that the
// JIT'ed ICs cannot assume the shape determines the prototype) or by just
// generating a new shape for the object. Choosing the former is bad if the
// object is on the prototype chain of other objects, as the uncacheable
// prototype can inhibit iterator caches on those objects and slow down
// prototype accesses. Choosing the latter is bad if there are many similar
// objects to this one which will have their prototype mutated, as the
// generateOwnShape forces the object into dictionary mode and similar
// property lineages will be repeatedly cloned.
//
// :XXX: bug 707717 make this code less brittle.
RootedObject oldproto(cx, obj);
while (oldproto && oldproto->isNative()) {
if (oldproto->isSingleton()) {
if (!oldproto->as<NativeObject>().generateOwnShape(cx))
return false;
} else {
if (!oldproto->setUncacheableProto(cx))
return false;
}
if (!obj->isDelegate()) {
// If |obj| is not a proto of another object, we don't need to
// reshape the whole proto chain.
MOZ_ASSERT(obj == oldproto);
break;
}
oldproto = oldproto->getProto();
}
if (proto.isObject() && !proto.toObject()->setDelegate(cx))
return false;
if (obj->isSingleton()) {
/*
* Just splice the prototype, but mark the properties as unknown for
* consistent behavior.
*/
if (!obj->splicePrototype(cx, clasp, proto))
return false;
MarkObjectGroupUnknownProperties(cx, obj->group());
return true;
}
if (proto.isObject()) {
RootedObject protoObj(cx, proto.toObject());
if (!JSObject::setNewGroupUnknown(cx, clasp, protoObj))
return false;
}
ObjectGroup* group = ObjectGroup::defaultNewGroup(cx, clasp, proto);
if (!group)
return false;
/*
* Setting __proto__ on an object that has escaped and may be referenced by
* other heap objects can only be done if the properties of both objects
* are unknown. Type sets containing this object will contain the original
* type but not the new type of the object, so we need to treat all such
* type sets as unknown.
*/
MarkObjectGroupUnknownProperties(cx, obj->group());
MarkObjectGroupUnknownProperties(cx, group);
obj->setGroup(group);
return true;
}
/* static */ bool
JSObject::changeToSingleton(JSContext* cx, HandleObject obj)
{
MOZ_ASSERT(!obj->isSingleton());
MarkObjectGroupUnknownProperties(cx, obj->group());
ObjectGroup* group = ObjectGroup::lazySingletonGroup(cx, obj->getClass(),
obj->getTaggedProto());
if (!group)
return false;
obj->group_ = group;
return true;
}
static bool
MaybeResolveConstructor(ExclusiveContext* cxArg, Handle<GlobalObject*> global, JSProtoKey key)
{
if (global->isStandardClassResolved(key))
return true;
if (!cxArg->shouldBeJSContext())
return false;
JSContext* cx = cxArg->asJSContext();
return GlobalObject::resolveConstructor(cx, global, key);
}
bool
js::GetBuiltinConstructor(ExclusiveContext* cx, JSProtoKey key, MutableHandleObject objp)
{
MOZ_ASSERT(key != JSProto_Null);
Rooted<GlobalObject*> global(cx, cx->global());
if (!MaybeResolveConstructor(cx, global, key))
return false;
objp.set(&global->getConstructor(key).toObject());
return true;
}
bool
js::GetBuiltinPrototype(ExclusiveContext* cx, JSProtoKey key, MutableHandleObject protop)
{
MOZ_ASSERT(key != JSProto_Null);
Rooted<GlobalObject*> global(cx, cx->global());
if (!MaybeResolveConstructor(cx, global, key))
return false;
protop.set(&global->getPrototype(key).toObject());
return true;
}
bool
js::IsStandardPrototype(JSObject* obj, JSProtoKey key)
{
GlobalObject& global = obj->global();
Value v = global.getPrototype(key);
return v.isObject() && obj == &v.toObject();
}
JSProtoKey
JS::IdentifyStandardInstance(JSObject* obj)
{
// Note: The prototype shares its JSClass with instances.
MOZ_ASSERT(!obj->is<CrossCompartmentWrapperObject>());
JSProtoKey key = StandardProtoKeyOrNull(obj);
if (key != JSProto_Null && !IsStandardPrototype(obj, key))
return key;
return JSProto_Null;
}
JSProtoKey
JS::IdentifyStandardPrototype(JSObject* obj)
{
// Note: The prototype shares its JSClass with instances.
MOZ_ASSERT(!obj->is<CrossCompartmentWrapperObject>());
JSProtoKey key = StandardProtoKeyOrNull(obj);
if (key != JSProto_Null && IsStandardPrototype(obj, key))
return key;
return JSProto_Null;
}
JSProtoKey
JS::IdentifyStandardInstanceOrPrototype(JSObject* obj)
{
return StandardProtoKeyOrNull(obj);
}
JSProtoKey
JS::IdentifyStandardConstructor(JSObject* obj)
{
// Note that NATIVE_CTOR does not imply that we are a standard constructor,
// but the converse is true (at least until we start having self-hosted
// constructors for standard classes). This lets us avoid a costly loop for
// many functions (which, depending on the call site, may be the common case).
if (!obj->is<JSFunction>() || !(obj->as<JSFunction>().flags() & JSFunction::NATIVE_CTOR))
return JSProto_Null;
GlobalObject& global = obj->global();
for (size_t k = 0; k < JSProto_LIMIT; ++k) {
JSProtoKey key = static_cast<JSProtoKey>(k);
if (global.getConstructor(key) == ObjectValue(*obj))
return key;
}
return JSProto_Null;
}
bool
JSObject::isCallable() const
{
if (is<JSFunction>())
return true;
return callHook() != nullptr;
}
bool
JSObject::isConstructor() const
{
if (is<JSFunction>()) {
const JSFunction& fun = as<JSFunction>();
return fun.isConstructor();
}
return constructHook() != nullptr;
}
JSNative
JSObject::callHook() const
{
const js::Class* clasp = getClass();
if (clasp->call)
return clasp->call;
if (is<js::ProxyObject>()) {
const js::ProxyObject& p = as<js::ProxyObject>();
if (p.handler()->isCallable(const_cast<JSObject*>(this)))
return js::proxy_Call;
}
return nullptr;
}
JSNative
JSObject::constructHook() const
{
const js::Class* clasp = getClass();
if (clasp->construct)
return clasp->construct;
if (is<js::ProxyObject>()) {
const js::ProxyObject& p = as<js::ProxyObject>();
if (p.handler()->isConstructor(const_cast<JSObject*>(this)))
return js::proxy_Construct;
}
return nullptr;
}
bool
js::LookupProperty(JSContext* cx, HandleObject obj, js::HandleId id,
MutableHandleObject objp, MutableHandleShape propp)
{
/* NB: The logic of lookupProperty is implicitly reflected in
* BaselineIC.cpp's |EffectlesslyLookupProperty| logic.
* If this changes, please remember to update the logic there as well.
*/
if (LookupPropertyOp op = obj->getOps()->lookupProperty)
return op(cx, obj, id, objp, propp);
return LookupPropertyInline<CanGC>(cx, obj.as<NativeObject>(), id, objp, propp);
}
bool
js::LookupName(JSContext* cx, HandlePropertyName name, HandleObject scopeChain,
MutableHandleObject objp, MutableHandleObject pobjp, MutableHandleShape propp)
{
RootedId id(cx, NameToId(name));
for (RootedObject scope(cx, scopeChain); scope; scope = scope->enclosingScope()) {
if (!LookupProperty(cx, scope, id, pobjp, propp))
return false;
if (propp) {
objp.set(scope);
return true;
}
}
objp.set(nullptr);
pobjp.set(nullptr);
propp.set(nullptr);
return true;
}
bool
js::LookupNameNoGC(JSContext* cx, PropertyName* name, JSObject* scopeChain,
JSObject** objp, JSObject** pobjp, Shape** propp)
{
AutoAssertNoException nogc(cx);
MOZ_ASSERT(!*objp && !*pobjp && !*propp);
for (JSObject* scope = scopeChain; scope; scope = scope->enclosingScope()) {
if (scope->getOps()->lookupProperty)
return false;
if (!LookupPropertyInline<NoGC>(cx, &scope->as<NativeObject>(), NameToId(name), pobjp, propp))
return false;
if (*propp) {
*objp = scope;
return true;
}
}
return true;
}
bool
js::LookupNameWithGlobalDefault(JSContext* cx, HandlePropertyName name, HandleObject scopeChain,
MutableHandleObject objp)
{
RootedId id(cx, NameToId(name));
RootedObject pobj(cx);
RootedShape shape(cx);
RootedObject scope(cx, scopeChain);
for (; !scope->is<GlobalObject>(); scope = scope->enclosingScope()) {
if (!LookupProperty(cx, scope, id, &pobj, &shape))
return false;
if (shape)
break;
}
objp.set(scope);
return true;
}
bool
js::LookupNameUnqualified(JSContext* cx, HandlePropertyName name, HandleObject scopeChain,
MutableHandleObject objp)
{
RootedId id(cx, NameToId(name));
RootedObject pobj(cx);
RootedShape shape(cx);
RootedObject scope(cx, scopeChain);
for (; !scope->isUnqualifiedVarObj(); scope = scope->enclosingScope()) {
if (!LookupProperty(cx, scope, id, &pobj, &shape))
return false;
if (shape)
break;
}
// See note above RuntimeLexicalErrorObject.
if (pobj == scope) {
if (name != cx->names().dotThis && IsUninitializedLexicalSlot(scope, shape)) {
scope = RuntimeLexicalErrorObject::create(cx, scope, JSMSG_UNINITIALIZED_LEXICAL);
if (!scope)
return false;
} else if (scope->is<ScopeObject>() && !scope->is<DeclEnvObject>() && !shape->writable()) {
MOZ_ASSERT(name != cx->names().dotThis);
scope = RuntimeLexicalErrorObject::create(cx, scope, JSMSG_BAD_CONST_ASSIGN);
if (!scope)
return false;
}
}
objp.set(scope);
return true;
}
bool
js::HasOwnProperty(JSContext* cx, HandleObject obj, HandleId id, bool* result)
{
if (obj->is<ProxyObject>())
return Proxy::hasOwn(cx, obj, id, result);
if (GetOwnPropertyOp op = obj->getOps()->getOwnPropertyDescriptor) {
Rooted<PropertyDescriptor> desc(cx);
if (!op(cx, obj, id, &desc))
return false;
*result = !!desc.object();
return true;
}
RootedShape shape(cx);
if (!NativeLookupOwnProperty<CanGC>(cx, obj.as<NativeObject>(), id, &shape))
return false;
*result = (shape != nullptr);
return true;
}
bool
js::LookupPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, JSObject** objp,
Shape** propp)
{
do {
if (obj->isNative()) {
/* Search for a native dense element, typed array element, or property. */
if (JSID_IS_INT(id) && obj->as<NativeObject>().containsDenseElement(JSID_TO_INT(id))) {
*objp = obj;
MarkDenseOrTypedArrayElementFound<NoGC>(propp);
return true;
}
if (IsAnyTypedArray(obj)) {
uint64_t index;
if (IsTypedArrayIndex(id, &index)) {
if (index < AnyTypedArrayLength(obj)) {
*objp = obj;
MarkDenseOrTypedArrayElementFound<NoGC>(propp);
} else {
*objp = nullptr;
*propp = nullptr;
}
return true;
}
}
if (Shape* shape = obj->as<NativeObject>().lookupPure(id)) {
*objp = obj;
*propp = shape;
return true;
}
// Fail if there's a resolve hook, unless the mayResolve hook tells
// us the resolve hook won't define a property with this id.
if (ClassMayResolveId(cx->names(), obj->getClass(), id, obj))
return false;
} else if (obj->is<UnboxedPlainObject>()) {
if (obj->as<UnboxedPlainObject>().containsUnboxedOrExpandoProperty(cx, id)) {
*objp = obj;
MarkNonNativePropertyFound<NoGC>(propp);
return true;
}
} else if (obj->is<UnboxedArrayObject>()) {
if (obj->as<UnboxedArrayObject>().containsProperty(cx, id)) {
*objp = obj;
MarkNonNativePropertyFound<NoGC>(propp);
return true;
}
} else if (obj->is<TypedObject>()) {
if (obj->as<TypedObject>().typeDescr().hasProperty(cx->names(), id)) {
*objp = obj;
MarkNonNativePropertyFound<NoGC>(propp);
return true;
}
} else {
return false;
}
obj = obj->getProto();
} while (obj);
*objp = nullptr;
*propp = nullptr;
return true;
}
static inline bool
NativeGetPureInline(NativeObject* pobj, Shape* shape, Value* vp)
{
/* Fail if we have a custom getter. */
if (!shape->hasDefaultGetter())
return false;
if (shape->hasSlot()) {
*vp = pobj->getSlot(shape->slot());
MOZ_ASSERT(!vp->isMagic());
} else {
vp->setUndefined();
}
return true;
}
bool
js::GetPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, Value* vp)
{
JSObject* pobj;
Shape* shape;
if (!LookupPropertyPure(cx, obj, id, &pobj, &shape))
return false;
if (!shape) {
vp->setUndefined();
return true;
}
return pobj->isNative() && NativeGetPureInline(&pobj->as<NativeObject>(), shape, vp);
}
bool
JSObject::reportReadOnly(JSContext* cx, jsid id, unsigned report)
{
RootedValue val(cx, IdToValue(id));
return ReportValueErrorFlags(cx, report, JSMSG_READ_ONLY,
JSDVG_IGNORE_STACK, val, nullptr,
nullptr, nullptr);
}
bool
JSObject::reportNotConfigurable(JSContext* cx, jsid id, unsigned report)
{
RootedValue val(cx, IdToValue(id));
return ReportValueErrorFlags(cx, report, JSMSG_CANT_DELETE,
JSDVG_IGNORE_STACK, val, nullptr,
nullptr, nullptr);
}
bool
JSObject::reportNotExtensible(JSContext* cx, unsigned report)
{
RootedValue val(cx, ObjectValue(*this));
return ReportValueErrorFlags(cx, report, JSMSG_OBJECT_NOT_EXTENSIBLE,
JSDVG_IGNORE_STACK, val, nullptr,
nullptr, nullptr);
}
// Our immutable-prototype behavior is non-standard, and it's unclear whether
// it's shippable. (Or at least it's unclear whether it's shippable with any
// provided-by-default uses exposed to script.) If this bool is true,
// immutable-prototype behavior is enforced; if it's false, behavior is not
// enforced, and immutable-prototype bits stored on objects are completely
// ignored.
static const bool ImmutablePrototypesEnabled = true;
JS_FRIEND_API(bool)
JS_ImmutablePrototypesEnabled()
{
return ImmutablePrototypesEnabled;
}
/*** ES6 standard internal methods ***************************************************************/
bool
js::SetPrototype(JSContext* cx, HandleObject obj, HandleObject proto, JS::ObjectOpResult& result)
{
/*
* If |obj| has a "lazy" [[Prototype]], it is 1) a proxy 2) whose handler's
* {get,set}Prototype and setImmutablePrototype methods mediate access to
* |obj.[[Prototype]]|. The Proxy subsystem is responsible for responding
* to such attempts.
*/
if (obj->hasLazyPrototype()) {
MOZ_ASSERT(obj->is<ProxyObject>());
return Proxy::setPrototype(cx, obj, proto, result);
}
/* Disallow mutation of immutable [[Prototype]]s. */
if (obj->nonLazyPrototypeIsImmutable() && ImmutablePrototypesEnabled)
return result.fail(JSMSG_CANT_SET_PROTO);
/*
* Disallow mutating the [[Prototype]] on ArrayBuffer objects, which
* due to their complicated delegate-object shenanigans can't easily
* have a mutable [[Prototype]].
*/
if (obj->is<ArrayBufferObject>()) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_CANT_SET_PROTO_OF,
"incompatible ArrayBuffer");
return false;
}
/*
* Disallow mutating the [[Prototype]] on Typed Objects, per the spec.
*/
if (obj->is<TypedObject>()) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_CANT_SET_PROTO_OF,
"incompatible TypedObject");
return false;
}
/*
* Explicitly disallow mutating the [[Prototype]] of Location objects
* for flash-related security reasons.
*/
if (!strcmp(obj->getClass()->name, "Location")) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_CANT_SET_PROTO_OF,
"incompatible Location object");
return false;
}
/*
* ES6 9.1.2 step 3-4 if |obj.[[Prototype]]| has SameValue as |proto| return true.
* Since the values in question are objects, we can just compare pointers.
*/
if (proto == obj->getProto())
return result.succeed();
/* ES6 9.1.2 step 5 forbids changing [[Prototype]] if not [[Extensible]]. */
bool extensible;
if (!IsExtensible(cx, obj, &extensible))
return false;
if (!extensible)
return result.fail(JSMSG_CANT_SET_PROTO);
// If this is a global object, resolve the Object class so that its
// [[Prototype]] chain is always properly immutable, even in the presence
// of lazy standard classes.
if (obj->is<GlobalObject>()) {
Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
if (!GlobalObject::ensureConstructor(cx, global, JSProto_Object))
return false;
}
/*
* ES6 9.1.2 step 6 forbids generating cyclical prototype chains. But we
* have to do this comparison on the observable WindowProxy, not on the
* possibly-Window object we're setting the proto on.
*/
RootedObject objMaybeWindowProxy(cx, ToWindowProxyIfWindow(obj));
RootedObject obj2(cx);
for (obj2 = proto; obj2; ) {
MOZ_ASSERT(!IsWindow(obj2));
if (obj2 == objMaybeWindowProxy)
return result.fail(JSMSG_CANT_SET_PROTO_CYCLE);
if (!GetPrototype(cx, obj2, &obj2))
return false;
}
// Convert unboxed objects to their native representations before changing
// their prototype/group, as they depend on the group for their layout.
if (!MaybeConvertUnboxedObjectToNative(cx, obj))
return false;
Rooted<TaggedProto> taggedProto(cx, TaggedProto(proto));
if (!SetClassAndProto(cx, obj, obj->getClass(), taggedProto))
return false;
return result.succeed();
}
bool
js::SetPrototype(JSContext* cx, HandleObject obj, HandleObject proto)
{
ObjectOpResult result;
return SetPrototype(cx, obj, proto, result) && result.checkStrict(cx, obj);
}
bool
js::PreventExtensions(JSContext* cx, HandleObject obj, ObjectOpResult& result)
{
if (obj->is<ProxyObject>())
return js::Proxy::preventExtensions(cx, obj, result);
if (!obj->nonProxyIsExtensible())
return result.succeed();
if (!MaybeConvertUnboxedObjectToNative(cx, obj))
return false;
// Force lazy properties to be resolved.
AutoIdVector props(cx);
if (!js::GetPropertyKeys(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY, &props))
return false;
// Convert all dense elements to sparse properties. This will shrink the
// initialized length and capacity of the object to zero and ensure that no
// new dense elements can be added without calling growElements(), which
// checks isExtensible().
if (obj->isNative()) {
if (!NativeObject::sparsifyDenseElements(cx, obj.as<NativeObject>()))
return false;
}