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cobalt / cobalt / ab2460b8a1a35a81b67dbaef0fa773657fed11e5 / . / src / third_party / mozjs / js / src / jsobj.cpp
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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 <string.h>
#include "mozilla/Util.h"
#include "jstypes.h"
#include "jsutil.h"
#include "jsprf.h"
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsfun.h"
#include "jsgc.h"
#include "jsiter.h"
#include "jsnum.h"
#include "jsopcode.h"
#include "jsproxy.h"
#include "jsscript.h"
#include "jsstr.h"
#include "jsdbgapi.h"
#include "jswatchpoint.h"
#include "jswrapper.h"
#include "frontend/BytecodeCompiler.h"
#include "gc/Marking.h"
#include "jit/BaselineJIT.h"
#include "js/MemoryMetrics.h"
#include "vm/Interpreter.h"
#include "vm/Shape.h"
#include "jsatominlines.h"
#include "jsboolinlines.h"
#include "jscntxtinlines.h"
#include "jscompartmentinlines.h"
#include "jstypedarrayinlines.h"
#include "builtin/Iterator-inl.h"
#include "vm/BooleanObject-inl.h"
#include "vm/NumberObject-inl.h"
#include "vm/RegExpStatics-inl.h"
#include "vm/Shape-inl.h"
#include "vm/StringObject-inl.h"
using namespace js;
using namespace js::gc;
using namespace js::types;
using js::frontend::IsIdentifier;
using mozilla::ArrayLength;
using mozilla::DebugOnly;
JS_STATIC_ASSERT(int32_t((JSObject::NELEMENTS_LIMIT - 1) * sizeof(Value)) == int64_t((JSObject::NELEMENTS_LIMIT - 1) * sizeof(Value)));
Class js::ObjectClass = {
js_Object_str,
JSCLASS_HAS_CACHED_PROTO(JSProto_Object),
JS_PropertyStub, /* addProperty */
JS_DeletePropertyStub, /* delProperty */
JS_PropertyStub, /* getProperty */
JS_StrictPropertyStub, /* setProperty */
JS_EnumerateStub,
JS_ResolveStub,
JS_ConvertStub
};
JS_FRIEND_API(JSObject *)
JS_ObjectToInnerObject(JSContext *cx, JSObject *objArg)
{
RootedObject obj(cx, objArg);
if (!obj) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_INACTIVE);
return NULL;
}
return GetInnerObject(cx, obj);
}
JS_FRIEND_API(JSObject *)
JS_ObjectToOuterObject(JSContext *cx, JSObject *obj_)
{
Rooted<JSObject*> obj(cx, obj_);
assertSameCompartment(cx, obj);
return GetOuterObject(cx, obj);
}
JSObject *
js::NonNullObject(JSContext *cx, const Value &v)
{
if (v.isPrimitive()) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_NOT_NONNULL_OBJECT);
return NULL;
}
return &v.toObject();
}
const char *
js::InformalValueTypeName(const Value &v)
{
if (v.isObject())
return v.toObject().getClass()->name;
if (v.isString())
return "string";
if (v.isNumber())
return "number";
if (v.isBoolean())
return "boolean";
if (v.isNull())
return "null";
if (v.isUndefined())
return "undefined";
return "value";
}
template <AllowGC allowGC>
JSBool
js::HasOwnProperty(JSContext *cx, LookupGenericOp lookup,
typename MaybeRooted<JSObject*, allowGC>::HandleType obj,
typename MaybeRooted<jsid, allowGC>::HandleType id,
typename MaybeRooted<JSObject*, allowGC>::MutableHandleType objp,
typename MaybeRooted<Shape*, allowGC>::MutableHandleType propp)
{
JSAutoResolveFlags rf(cx, 0);
if (lookup) {
if (!allowGC)
return false;
if (!lookup(cx,
MaybeRooted<JSObject*, allowGC>::toHandle(obj),
MaybeRooted<jsid, allowGC>::toHandle(id),
MaybeRooted<JSObject*, allowGC>::toMutableHandle(objp),
MaybeRooted<Shape*, allowGC>::toMutableHandle(propp)))
{
return false;
}
} else {
if (!baseops::LookupProperty<allowGC>(cx, obj, id, objp, propp))
return false;
}
if (!propp)
return true;
if (objp == obj)
return true;
JSObject *outer = NULL;
if (JSObjectOp op = objp->getClass()->ext.outerObject) {
if (!allowGC)
return false;
RootedObject inner(cx, objp);
outer = op(cx, inner);
if (!outer)
return false;
}
if (outer != objp)
propp.set(NULL);
return true;
}
template JSBool
js::HasOwnProperty<CanGC>(JSContext *cx, LookupGenericOp lookup,
HandleObject obj, HandleId id,
MutableHandleObject objp, MutableHandleShape propp);
template JSBool
js::HasOwnProperty<NoGC>(JSContext *cx, LookupGenericOp lookup,
JSObject *obj, jsid id,
FakeMutableHandle<JSObject*> objp, FakeMutableHandle<Shape*> propp);
bool
js::NewPropertyDescriptorObject(JSContext *cx, const PropertyDescriptor *desc,
MutableHandleValue vp)
{
if (!desc->obj) {
vp.setUndefined();
return true;
}
/* We have our own property, so start creating the descriptor. */
AutoPropDescRooter d(cx);
d.initFromPropertyDescriptor(*desc);
if (!d.makeObject(cx))
return false;
vp.set(d.pd());
return true;
}
void
PropDesc::initFromPropertyDescriptor(const PropertyDescriptor &desc)
{
isUndefined_ = false;
pd_.setUndefined();
attrs = uint8_t(desc.attrs);
JS_ASSERT_IF(attrs & JSPROP_READONLY, !(attrs & (JSPROP_GETTER | JSPROP_SETTER)));
if (desc.attrs & (JSPROP_GETTER | JSPROP_SETTER)) {
hasGet_ = true;
get_ = ((desc.attrs & JSPROP_GETTER) && desc.getter)
? CastAsObjectJsval(desc.getter)
: UndefinedValue();
hasSet_ = true;
set_ = ((desc.attrs & JSPROP_SETTER) && desc.setter)
? CastAsObjectJsval(desc.setter)
: UndefinedValue();
hasValue_ = false;
value_.setUndefined();
hasWritable_ = false;
} else {
hasGet_ = false;
get_.setUndefined();
hasSet_ = false;
set_.setUndefined();
hasValue_ = true;
value_ = desc.value;
hasWritable_ = true;
}
hasEnumerable_ = true;
hasConfigurable_ = true;
}
bool
PropDesc::makeObject(JSContext *cx)
{
MOZ_ASSERT(!isUndefined());
RootedObject obj(cx, NewBuiltinClassInstance(cx, &ObjectClass));
if (!obj)
return false;
const JSAtomState &names = cx->names();
RootedValue configurableVal(cx, BooleanValue((attrs & JSPROP_PERMANENT) == 0));
RootedValue enumerableVal(cx, BooleanValue((attrs & JSPROP_ENUMERATE) != 0));
RootedValue writableVal(cx, BooleanValue((attrs & JSPROP_READONLY) == 0));
if ((hasConfigurable() &&
!JSObject::defineProperty(cx, obj, names.configurable, configurableVal)) ||
(hasEnumerable() &&
!JSObject::defineProperty(cx, obj, names.enumerable, enumerableVal)) ||
(hasGet() &&
!JSObject::defineProperty(cx, obj, names.get, getterValue())) ||
(hasSet() &&
!JSObject::defineProperty(cx, obj, names.set, setterValue())) ||
(hasValue() &&
!JSObject::defineProperty(cx, obj, names.value, value())) ||
(hasWritable() &&
!JSObject::defineProperty(cx, obj, names.writable, writableVal)))
{
return false;
}
pd_.setObject(*obj);
return true;
}
bool
js::GetOwnPropertyDescriptor(JSContext *cx, HandleObject obj, HandleId id,
PropertyDescriptor *desc)
{
// FIXME: Call TrapGetOwnProperty directly once ScriptedIndirectProxies is removed
if (obj->isProxy())
return Proxy::getOwnPropertyDescriptor(cx, obj, id, desc, 0);
RootedObject pobj(cx);
RootedShape shape(cx);
if (!HasOwnProperty<CanGC>(cx, obj->getOps()->lookupGeneric, obj, id, &pobj, &shape))
return false;
if (!shape) {
desc->obj = NULL;
return true;
}
bool doGet = true;
if (pobj->isNative()) {
desc->attrs = GetShapeAttributes(shape);
if (desc->attrs & (JSPROP_GETTER | JSPROP_SETTER)) {
MOZ_ASSERT(desc.isShared());
doGet = false;
if (desc->attrs & JSPROP_GETTER)
desc->getter = CastAsPropertyOp(shape->getterObject());
if (desc->attrs & JSPROP_SETTER)
desc->setter = CastAsStrictPropertyOp(shape->setterObject());
} else {
// This is either a straight-up data property or (rarely) a
// property with a JSPropertyOp getter/setter. The latter must be
// reported to the caller as a plain data property, so don't
// populate desc.getter/setter, and mask away the SHARED bit.
desc->attrs &= ~JSPROP_SHARED;
}
} else {
if (!JSObject::getGenericAttributes(cx, pobj, id, &desc->attrs))
return false;
}
RootedValue value(cx);
if (doGet && !JSObject::getGeneric(cx, obj, obj, id, &value))
return false;
desc->value = value;
desc->obj = obj;
return true;
}
bool
js::GetOwnPropertyDescriptor(JSContext *cx, HandleObject obj, HandleId id, MutableHandleValue vp)
{
AutoPropertyDescriptorRooter desc(cx);
return GetOwnPropertyDescriptor(cx, obj, id, &desc) &&
NewPropertyDescriptorObject(cx, &desc, vp);
}
bool
js::GetFirstArgumentAsObject(JSContext *cx, const CallArgs &args, const char *method,
MutableHandleObject objp)
{
if (args.length() == 0) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_MORE_ARGS_NEEDED,
method, "0", "s");
return false;
}
HandleValue v = args.handleAt(0);
if (!v.isObject()) {
char *bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, v, NullPtr());
if (!bytes)
return false;
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_UNEXPECTED_TYPE,
bytes, "not an object");
js_free(bytes);
return false;
}
objp.set(&v.toObject());
return true;
}
static bool
HasProperty(JSContext *cx, HandleObject obj, HandleId id, MutableHandleValue vp, bool *foundp)
{
if (!JSObject::hasProperty(cx, obj, id, foundp, 0))
return false;
if (!*foundp) {
vp.setUndefined();
return true;
}
/*
* We must go through the method read barrier in case id is 'get' or 'set'.
* There is no obvious way to defer cloning a joined function object whose
* identity will be used by DefinePropertyOnObject, e.g., or reflected via
* js::GetOwnPropertyDescriptor, as the getter or setter callable object.
*/
return !!JSObject::getGeneric(cx, obj, obj, id, vp);
}
bool
PropDesc::initialize(JSContext *cx, const Value &origval, bool checkAccessors)
{
RootedValue v(cx, origval);
/* 8.10.5 step 1 */
if (v.isPrimitive()) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_NOT_NONNULL_OBJECT);
return false;
}
RootedObject desc(cx, &v.toObject());
/* Make a copy of the descriptor. We might need it later. */
pd_ = v;
isUndefined_ = false;
/*
* Start with the proper defaults. XXX shouldn't be necessary when we get
* rid of PropDesc::attributes()
*/
attrs = JSPROP_PERMANENT | JSPROP_READONLY;
bool found = false;
RootedId id(cx);
/* 8.10.5 step 3 */
id = NameToId(cx->names().enumerable);
if (!HasProperty(cx, desc, id, &v, &found))
return false;
if (found) {
hasEnumerable_ = true;
if (ToBoolean(v))
attrs |= JSPROP_ENUMERATE;
}
/* 8.10.5 step 4 */
id = NameToId(cx->names().configurable);
if (!HasProperty(cx, desc, id, &v, &found))
return false;
if (found) {
hasConfigurable_ = true;
if (ToBoolean(v))
attrs &= ~JSPROP_PERMANENT;
}
/* 8.10.5 step 5 */
id = NameToId(cx->names().value);
if (!HasProperty(cx, desc, id, &v, &found))
return false;
if (found) {
hasValue_ = true;
value_ = v;
}
/* 8.10.6 step 6 */
id = NameToId(cx->names().writable);
if (!HasProperty(cx, desc, id, &v, &found))
return false;
if (found) {
hasWritable_ = true;
if (ToBoolean(v))
attrs &= ~JSPROP_READONLY;
}
/* 8.10.7 step 7 */
id = NameToId(cx->names().get);
if (!HasProperty(cx, desc, id, &v, &found))
return false;
if (found) {
hasGet_ = true;
get_ = v;
attrs |= JSPROP_GETTER | JSPROP_SHARED;
attrs &= ~JSPROP_READONLY;
if (checkAccessors && !checkGetter(cx))
return false;
}
/* 8.10.7 step 8 */
id = NameToId(cx->names().set);
if (!HasProperty(cx, desc, id, &v, &found))
return false;
if (found) {
hasSet_ = true;
set_ = v;
attrs |= JSPROP_SETTER | JSPROP_SHARED;
attrs &= ~JSPROP_READONLY;
if (checkAccessors && !checkSetter(cx))
return false;
}
/* 8.10.7 step 9 */
if ((hasGet() || hasSet()) && (hasValue() || hasWritable())) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_INVALID_DESCRIPTOR);
return false;
}
JS_ASSERT_IF(attrs & JSPROP_READONLY, !(attrs & (JSPROP_GETTER | JSPROP_SETTER)));
return true;
}
void
PropDesc::complete()
{
if (isGenericDescriptor() || isDataDescriptor()) {
if (!hasValue_) {
hasValue_ = true;
value_.setUndefined();
}
if (!hasWritable_) {
hasWritable_ = true;
attrs |= JSPROP_READONLY;
}
} else {
if (!hasGet_) {
hasGet_ = true;
get_.setUndefined();
}
if (!hasSet_) {
hasSet_ = true;
set_.setUndefined();
}
}
if (!hasEnumerable_) {
hasEnumerable_ = true;
attrs &= ~JSPROP_ENUMERATE;
}
if (!hasConfigurable_) {
hasConfigurable_ = true;
attrs |= JSPROP_PERMANENT;
}
}
bool
js::Throw(JSContext *cx, jsid id, unsigned errorNumber)
{
JS_ASSERT(js_ErrorFormatString[errorNumber].argCount == 1);
JSString *idstr = IdToString(cx, id);
if (!idstr)
return false;
JSAutoByteString bytes(cx, idstr);
if (!bytes)
return false;
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, 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));
js_ReportValueErrorFlags(cx, JSREPORT_ERROR, errorNumber,
JSDVG_IGNORE_STACK, val, NullPtr(),
NULL, NULL);
} else {
JS_ASSERT(js_ErrorFormatString[errorNumber].argCount == 0);
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, errorNumber);
}
return false;
}
static JSBool
Reject(JSContext *cx, unsigned errorNumber, bool throwError, jsid id, bool *rval)
{
if (throwError)
return Throw(cx, id, errorNumber);
*rval = false;
return true;
}
static JSBool
Reject(JSContext *cx, JSObject *obj, unsigned errorNumber, bool throwError, bool *rval)
{
if (throwError)
return Throw(cx, obj, errorNumber);
*rval = false;
return JS_TRUE;
}
static bool
Reject(JSContext *cx, HandleId id, unsigned errorNumber, bool throwError, bool *rval)
{
if (throwError)
return Throw(cx, id, errorNumber);
*rval = false;
return true;
}
// See comments on CheckDefineProperty in jsobj.h.
//
// DefinePropertyOnObject has its own implementation of these checks.
//
bool
js::CheckDefineProperty(JSContext *cx, HandleObject obj, HandleId id, HandleValue value,
PropertyOp getter, StrictPropertyOp setter, unsigned attrs)
{
if (!obj->isNative())
return true;
// ES5 8.12.9 Step 1. Even though we know obj is native, we use generic
// APIs for shorter, more readable code.
AutoPropertyDescriptorRooter desc(cx);
if (!GetOwnPropertyDescriptor(cx, obj, id, &desc))
return false;
// This does not have to check obj->isExtensible() when !desc.obj (steps
// 2-3) because the low-level methods JSObject::{add,put}Property check
// for that.
if (desc.obj && (desc.attrs & JSPROP_PERMANENT)) {
// Steps 6-11, skipping step 10.a.ii. Prohibit redefining a permanent
// property with different metadata, except to make a writable property
// non-writable.
if (getter != desc.getter ||
setter != desc.setter ||
(attrs != desc.attrs && attrs != (desc.attrs | JSPROP_READONLY)))
{
return Throw(cx, id, JSMSG_CANT_REDEFINE_PROP);
}
// Step 10.a.ii. Prohibit changing the value of a non-configurable,
// non-writable data property.
if ((desc.attrs & (JSPROP_GETTER | JSPROP_SETTER | JSPROP_READONLY)) == JSPROP_READONLY) {
bool same;
if (!SameValue(cx, value, desc.value, &same))
return false;
if (!same)
return JSObject::reportReadOnly(cx, id);
}
}
return true;
}
static JSBool
DefinePropertyOnObject(JSContext *cx, HandleObject obj, HandleId id, const PropDesc &desc,
bool throwError, bool *rval)
{
/* 8.12.9 step 1. */
RootedShape shape(cx);
RootedObject obj2(cx);
JS_ASSERT(!obj->getOps()->lookupGeneric);
if (!HasOwnProperty<CanGC>(cx, NULL, obj, id, &obj2, &shape))
return JS_FALSE;
JS_ASSERT(!obj->getOps()->defineProperty);
/* 8.12.9 steps 2-4. */
if (!shape) {
if (!obj->isExtensible())
return Reject(cx, obj, JSMSG_OBJECT_NOT_EXTENSIBLE, throwError, rval);
*rval = true;
if (desc.isGenericDescriptor() || desc.isDataDescriptor()) {
JS_ASSERT(!obj->getOps()->defineProperty);
RootedValue v(cx, desc.hasValue() ? desc.value() : UndefinedValue());
return baseops::DefineGeneric(cx, obj, id, v,
JS_PropertyStub, JS_StrictPropertyStub,
desc.attributes());
}
JS_ASSERT(desc.isAccessorDescriptor());
/*
* Getters and setters are just like watchpoints from an access
* control point of view.
*/
RootedValue dummy(cx);
unsigned dummyAttrs;
if (!CheckAccess(cx, obj, id, JSACC_WATCH, &dummy, &dummyAttrs))
return JS_FALSE;
RootedValue tmp(cx, UndefinedValue());
return baseops::DefineGeneric(cx, obj, id, tmp,
desc.getter(), desc.setter(), desc.attributes());
}
/* 8.12.9 steps 5-6 (note 5 is merely a special case of 6). */
RootedValue v(cx, UndefinedValue());
JS_ASSERT(obj == obj2);
bool shapeDataDescriptor = true,
shapeAccessorDescriptor = false,
shapeWritable = true,
shapeConfigurable = true,
shapeEnumerable = true,
shapeHasDefaultGetter = true,
shapeHasDefaultSetter = true,
shapeHasGetterValue = false,
shapeHasSetterValue = false;
uint8_t shapeAttributes = JSPROP_ENUMERATE;
if (!IsImplicitDenseElement(shape)) {
shapeDataDescriptor = shape->isDataDescriptor();
shapeAccessorDescriptor = shape->isAccessorDescriptor();
shapeWritable = shape->writable();
shapeConfigurable = shape->configurable();
shapeEnumerable = shape->enumerable();
shapeHasDefaultGetter = shape->hasDefaultGetter();
shapeHasDefaultSetter = shape->hasDefaultSetter();
shapeHasGetterValue = shape->hasGetterValue();
shapeHasSetterValue = shape->hasSetterValue();
shapeAttributes = shape->attributes();
}
do {
if (desc.isAccessorDescriptor()) {
if (!shapeAccessorDescriptor)
break;
if (desc.hasGet()) {
bool same;
if (!SameValue(cx, desc.getterValue(), shape->getterOrUndefined(), &same))
return false;
if (!same)
break;
}
if (desc.hasSet()) {
bool same;
if (!SameValue(cx, desc.setterValue(), shape->setterOrUndefined(), &same))
return false;
if (!same)
break;
}
} else {
/*
* Determine the current value of the property once, if the current
* value might actually need to be used or preserved later. NB: we
* guard on whether the current property is a data descriptor to
* avoid calling a getter; we won't need the value if it's not a
* data descriptor.
*/
if (IsImplicitDenseElement(shape)) {
v = obj->getDenseElement(JSID_TO_INT(id));
} else if (shape->isDataDescriptor()) {
/*
* We must rule out a non-configurable js::PropertyOp-guarded
* property becoming a writable unguarded data property, since
* such a property can have its value changed to one the getter
* and setter preclude.
*
* A desc lacking writable but with value is a data descriptor
* and we must reject it as if it had writable: true if current
* is writable.
*/
if (!shape->configurable() &&
(!shape->hasDefaultGetter() || !shape->hasDefaultSetter()) &&
desc.isDataDescriptor() &&
(desc.hasWritable() ? desc.writable() : shape->writable()))
{
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
}
if (!js_NativeGet(cx, obj, obj2, shape, 0, &v))
return JS_FALSE;
}
if (desc.isDataDescriptor()) {
if (!shapeDataDescriptor)
break;
bool same;
if (desc.hasValue()) {
if (!SameValue(cx, desc.value(), v, &same))
return false;
if (!same) {
/*
* Insist that a non-configurable js::PropertyOp data
* property is frozen at exactly the last-got value.
*
* Duplicate the first part of the big conjunction that
* we tested above, rather than add a local bool flag.
* Likewise, don't try to keep shape->writable() in a
* flag we veto from true to false for non-configurable
* PropertyOp-based data properties and test before the
* SameValue check later on in order to re-use that "if
* (!SameValue) Reject" logic.
*
* This function is large and complex enough that it
* seems best to repeat a small bit of code and return
* Reject(...) ASAP, instead of being clever.
*/
if (!shapeConfigurable &&
(!shape->hasDefaultGetter() || !shape->hasDefaultSetter()))
{
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
}
break;
}
}
if (desc.hasWritable() && desc.writable() != shapeWritable)
break;
} else {
/* The only fields in desc will be handled below. */
JS_ASSERT(desc.isGenericDescriptor());
}
}
if (desc.hasConfigurable() && desc.configurable() != shapeConfigurable)
break;
if (desc.hasEnumerable() && desc.enumerable() != shapeEnumerable)
break;
/* The conditions imposed by step 5 or step 6 apply. */
*rval = true;
return true;
} while (0);
/* 8.12.9 step 7. */
if (!shapeConfigurable) {
if ((desc.hasConfigurable() && desc.configurable()) ||
(desc.hasEnumerable() && desc.enumerable() != shape->enumerable())) {
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
}
}
bool callDelProperty = false;
if (desc.isGenericDescriptor()) {
/* 8.12.9 step 8, no validation required */
} else if (desc.isDataDescriptor() != shapeDataDescriptor) {
/* 8.12.9 step 9. */
if (!shapeConfigurable)
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
} else if (desc.isDataDescriptor()) {
/* 8.12.9 step 10. */
JS_ASSERT(shapeDataDescriptor);
if (!shapeConfigurable && !shape->writable()) {
if (desc.hasWritable() && desc.writable())
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
if (desc.hasValue()) {
bool same;
if (!SameValue(cx, desc.value(), v, &same))
return false;
if (!same)
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
}
}
callDelProperty = !shapeHasDefaultGetter || !shapeHasDefaultSetter;
} else {
/* 8.12.9 step 11. */
JS_ASSERT(desc.isAccessorDescriptor() && shape->isAccessorDescriptor());
if (!shape->configurable()) {
if (desc.hasSet()) {
bool same;
if (!SameValue(cx, desc.setterValue(), shape->setterOrUndefined(), &same))
return false;
if (!same)
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
}
if (desc.hasGet()) {
bool same;
if (!SameValue(cx, desc.getterValue(), shape->getterOrUndefined(), &same))
return false;
if (!same)
return Reject(cx, JSMSG_CANT_REDEFINE_PROP, throwError, id, rval);
}
}
}
/* 8.12.9 step 12. */
unsigned attrs;
PropertyOp getter;
StrictPropertyOp setter;
if (desc.isGenericDescriptor()) {
unsigned changed = 0;
if (desc.hasConfigurable())
changed |= JSPROP_PERMANENT;
if (desc.hasEnumerable())
changed |= JSPROP_ENUMERATE;
attrs = (shapeAttributes & ~changed) | (desc.attributes() & changed);
getter = IsImplicitDenseElement(shape) ? JS_PropertyStub : shape->getter();
setter = IsImplicitDenseElement(shape) ? JS_StrictPropertyStub : shape->setter();
} else if (desc.isDataDescriptor()) {
unsigned unchanged = 0;
if (!desc.hasConfigurable())
unchanged |= JSPROP_PERMANENT;
if (!desc.hasEnumerable())
unchanged |= JSPROP_ENUMERATE;
/* Watch out for accessor -> data transformations here. */
if (!desc.hasWritable() && shapeDataDescriptor)
unchanged |= JSPROP_READONLY;
if (desc.hasValue())
v = desc.value();
attrs = (desc.attributes() & ~unchanged) | (shapeAttributes & unchanged);
getter = JS_PropertyStub;
setter = JS_StrictPropertyStub;
} else {
JS_ASSERT(desc.isAccessorDescriptor());
/*
* Getters and setters are just like watchpoints from an access
* control point of view.
*/
RootedValue dummy(cx);
if (!CheckAccess(cx, obj2, id, JSACC_WATCH, &dummy, &attrs))
return JS_FALSE;
/* 8.12.9 step 12. */
unsigned changed = 0;
if (desc.hasConfigurable())
changed |= JSPROP_PERMANENT;
if (desc.hasEnumerable())
changed |= JSPROP_ENUMERATE;
if (desc.hasGet())
changed |= JSPROP_GETTER | JSPROP_SHARED | JSPROP_READONLY;
if (desc.hasSet())
changed |= JSPROP_SETTER | JSPROP_SHARED | JSPROP_READONLY;
attrs = (desc.attributes() & changed) | (shapeAttributes & ~changed);
if (desc.hasGet()) {
getter = desc.getter();
} else {
getter = (shapeHasDefaultGetter && !shapeHasGetterValue)
? JS_PropertyStub
: shape->getter();
}
if (desc.hasSet()) {
setter = desc.setter();
} else {
setter = (shapeHasDefaultSetter && !shapeHasSetterValue)
? JS_StrictPropertyStub
: shape->setter();
}
}
*rval = true;
/*
* Since "data" properties implemented using native C functions may rely on
* side effects during setting, we must make them aware that they have been
* "assigned"; deleting the property before redefining it does the trick.
* See bug 539766, where we ran into problems when we redefined
* arguments.length without making the property aware that its value had
* been changed (which would have happened if we had deleted it before
* redefining it or we had invoked its setter to change its value).
*/
if (callDelProperty) {
JSBool succeeded;
if (!CallJSDeletePropertyOp(cx, obj2->getClass()->delProperty, obj2, id, &succeeded))
return false;
}
return baseops::DefineGeneric(cx, obj, id, v, getter, setter, attrs);
}
/* ES6 20130308 draft 8.4.2.1 [[DefineOwnProperty]] */
static JSBool
DefinePropertyOnArray(JSContext *cx, HandleObject obj, HandleId id, const PropDesc &desc,
bool throwError, bool *rval)
{
JS_ASSERT(obj->isArray());
/* Step 2. */
if (id == NameToId(cx->names().length)) {
// Canonicalize value, if necessary, before proceeding any further. It
// would be better if this were always/only done by ArraySetLength.
// But canonicalization may throw a RangeError (or other exception, if
// the value is an object with user-defined conversion semantics)
// before other attributes are checked. So as long as our internal
// defineProperty hook doesn't match the ECMA one, this duplicate
// checking can't be helped.
RootedValue v(cx);
if (desc.hasValue()) {
uint32_t newLen;
if (!CanonicalizeArrayLengthValue(cx, desc.value(), &newLen))
return false;
v.setNumber(newLen);
} else {
v.setNumber(obj->getArrayLength());
}
if (desc.hasConfigurable() && desc.configurable())
return Reject(cx, id, JSMSG_CANT_REDEFINE_PROP, throwError, rval);
if (desc.hasEnumerable() && desc.enumerable())
return Reject(cx, id, JSMSG_CANT_REDEFINE_PROP, throwError, rval);
if (desc.isAccessorDescriptor())
return Reject(cx, id, JSMSG_CANT_REDEFINE_PROP, throwError, rval);
unsigned attrs = obj->nativeLookup(cx, id)->attributes();
if (!obj->arrayLengthIsWritable()) {
if (desc.hasWritable() && desc.writable())
return Reject(cx, id, JSMSG_CANT_REDEFINE_PROP, throwError, rval);
} else {
if (desc.hasWritable() && !desc.writable())
attrs = attrs | JSPROP_READONLY;
}
return ArraySetLength(cx, obj, id, attrs, v, throwError);
}
/* Step 3. */
uint32_t index;
if (js_IdIsIndex(id, &index)) {
/* Step 3b. */
uint32_t oldLen = obj->getArrayLength();
/* Steps 3a, 3e. */
if (index >= oldLen && !obj->arrayLengthIsWritable())
return Reject(cx, obj, JSMSG_CANT_APPEND_TO_ARRAY, throwError, rval);
/* Steps 3f-j. */
return DefinePropertyOnObject(cx, obj, id, desc, throwError, rval);
}
/* Step 4. */
return DefinePropertyOnObject(cx, obj, id, desc, throwError, rval);
}
bool
js::DefineProperty(JSContext *cx, HandleObject obj, HandleId id, const PropDesc &desc,
bool throwError, bool *rval)
{
if (obj->isArray())
return DefinePropertyOnArray(cx, obj, id, desc, throwError, rval);
if (obj->getOps()->lookupGeneric) {
/*
* FIXME: Once ScriptedIndirectProxies are removed, this code should call
* TrapDefineOwnProperty directly
*/
if (obj->isProxy()) {
RootedValue pd(cx, desc.pd());
return Proxy::defineProperty(cx, obj, id, pd);
}
return Reject(cx, obj, JSMSG_OBJECT_NOT_EXTENSIBLE, throwError, rval);
}
return DefinePropertyOnObject(cx, obj, id, desc, throwError, rval);
}
JSBool
js::DefineOwnProperty(JSContext *cx, HandleObject obj, HandleId id, HandleValue descriptor,
JSBool *bp)
{
AutoPropDescArrayRooter descs(cx);
PropDesc *desc = descs.append();
if (!desc || !desc->initialize(cx, descriptor))
return false;
bool rval;
if (!DefineProperty(cx, obj, id, *desc, true, &rval))
return false;
*bp = !!rval;
return true;
}
JSBool
js::DefineOwnProperty(JSContext *cx, HandleObject obj, HandleId id,
const PropertyDescriptor &descriptor, JSBool *bp)
{
AutoPropDescArrayRooter descs(cx);
PropDesc *desc = descs.append();
if (!desc)
return false;
desc->initFromPropertyDescriptor(descriptor);
bool rval;
if (!DefineProperty(cx, obj, id, *desc, true, &rval))
return false;
*bp = !!rval;
return true;
}
bool
js::ReadPropertyDescriptors(JSContext *cx, HandleObject props, bool checkAccessors,
AutoIdVector *ids, AutoPropDescArrayRooter *descs)
{
if (!GetPropertyNames(cx, props, JSITER_OWNONLY, ids))
return false;
RootedId id(cx);
for (size_t i = 0, len = ids->length(); i < len; i++) {
id = (*ids)[i];
PropDesc* desc = descs->append();
RootedValue v(cx);
if (!desc ||
!JSObject::getGeneric(cx, props, props, id, &v) ||
!desc->initialize(cx, v, checkAccessors))
{
return false;
}
}
return true;
}
// Duplicated in Object.cpp
static bool
DefineProperties(JSContext *cx, HandleObject obj, HandleObject props)
{
AutoIdVector ids(cx);
AutoPropDescArrayRooter descs(cx);
if (!ReadPropertyDescriptors(cx, props, true, &ids, &descs))
return false;
bool dummy;
for (size_t i = 0, len = ids.length(); i < len; i++) {
if (!DefineProperty(cx, obj, ids.handleAt(i), descs[i], true, &dummy))
return false;
}
return true;
}
extern JSBool
js_PopulateObject(JSContext *cx, HandleObject newborn, HandleObject props)
{
return DefineProperties(cx, newborn, props);
}
/* static */ inline unsigned
JSObject::getSealedOrFrozenAttributes(unsigned attrs, ImmutabilityType it)
{
/* Make all attributes permanent; if freezing, make data attributes read-only. */
if (it == FREEZE && !(attrs & (JSPROP_GETTER | JSPROP_SETTER)))
return JSPROP_PERMANENT | JSPROP_READONLY;
return JSPROP_PERMANENT;
}
/* static */ bool
JSObject::sealOrFreeze(JSContext *cx, HandleObject obj, ImmutabilityType it)
{
assertSameCompartment(cx, obj);
JS_ASSERT(it == SEAL || it == FREEZE);
if (obj->isExtensible() && !JSObject::preventExtensions(cx, obj))
return false;
AutoIdVector props(cx);
if (!GetPropertyNames(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY, &props))
return false;
/* preventExtensions must sparsify dense objects, so we can assign to holes without checks. */
JS_ASSERT_IF(obj->isNative(), obj->getDenseCapacity() == 0);
if (obj->isNative() && !obj->inDictionaryMode()) {
/*
* 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, obj->getClass(),
obj->getTaggedProto(),
obj->getParent(),
obj->getMetadata(),
obj->numFixedSlots(),
obj->lastProperty()->getObjectFlags()));
if (!last)
return false;
/* Get an in order list of the shapes in this object. */
AutoShapeVector shapes(cx);
for (Shape::Range<NoGC> r(obj->lastProperty()); !r.empty(); r.popFront()) {
if (!shapes.append(&r.front()))
return false;
}
Reverse(shapes.begin(), shapes.end());
for (size_t i = 0; i < shapes.length(); i++) {
StackShape child(shapes[i]);
StackShape::AutoRooter rooter(cx, &child);
child.attrs |= getSealedOrFrozenAttributes(child.attrs, it);
if (!JSID_IS_EMPTY(child.propid))
MarkTypePropertyConfigured(cx, obj, child.propid);
last = cx->propertyTree().getChild(cx, last, obj->numFixedSlots(), child);
if (!last)
return false;
}
JS_ASSERT(obj->lastProperty()->slotSpan() == last->slotSpan());
JS_ALWAYS_TRUE(setLastProperty(cx, obj, last));
} else {
RootedId id(cx);
for (size_t i = 0; i < props.length(); i++) {
id = props[i];
unsigned attrs;
if (!getGenericAttributes(cx, obj, id, &attrs))
return false;
unsigned new_attrs = getSealedOrFrozenAttributes(attrs, it);
/* If we already have the attributes we need, skip the setAttributes call. */
if ((attrs | new_attrs) == attrs)
continue;
attrs |= new_attrs;
if (!setGenericAttributes(cx, obj, id, &attrs))
return false;
}
}
// Ordinarily ArraySetLength handles this, but we're going behind its back
// right now, so we must do this manually. Neither the custom property
// tree mutations nor the setGenericAttributes call in the above code will
// do this for us.
//
// 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 before the if-else above.)
if (it == FREEZE && obj->isArray())
obj->getElementsHeader()->setNonwritableArrayLength();
return true;
}
/* static */ bool
JSObject::isSealedOrFrozen(JSContext *cx, HandleObject obj, ImmutabilityType it, bool *resultp)
{
if (obj->isExtensible()) {
*resultp = false;
return true;
}
AutoIdVector props(cx);
if (!GetPropertyNames(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY, &props))
return false;
RootedId id(cx);
for (size_t i = 0, len = props.length(); i < len; i++) {
id = props[i];
unsigned attrs;
if (!getGenericAttributes(cx, obj, id, &attrs))
return false;
/*
* If the property is configurable, this object is neither sealed nor
* frozen. If the property is a writable data property, this object is
* not frozen.
*/
if (!(attrs & JSPROP_PERMANENT) ||
(it == FREEZE && !(attrs & (JSPROP_READONLY | JSPROP_GETTER | JSPROP_SETTER))))
{
*resultp = false;
return true;
}
}
/* All properties checked out. This object is sealed/frozen. */
*resultp = true;
return true;
}
/* static */
const char *
JSObject::className(JSContext *cx, HandleObject obj)
{
assertSameCompartment(cx, obj);
if (obj->isProxy())
return Proxy::className(cx, obj);
return obj->getClass()->name;
}
/*
* 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(js::Class *clasp)
{
if (clasp == &ArrayClass)
return gc::FINALIZE_OBJECT8;
if (clasp == &JSFunction::class_)
return gc::FINALIZE_OBJECT2;
return gc::FINALIZE_OBJECT4;
}
static inline JSObject *
NewObject(JSContext *cx, Class *clasp, types::TypeObject *type_, JSObject *parent,
gc::AllocKind kind, NewObjectKind newKind)
{
JS_ASSERT(clasp != &ArrayClass);
JS_ASSERT_IF(clasp == &JSFunction::class_,
kind == JSFunction::FinalizeKind || kind == JSFunction::ExtendedFinalizeKind);
JS_ASSERT_IF(parent, &parent->global() == cx->compartment()->maybeGlobal());
RootedTypeObject type(cx, type_);
RootedShape shape(cx, EmptyShape::getInitialShape(cx, clasp, TaggedProto(type->proto),
parent, NewObjectMetadata(cx), kind));
if (!shape)
return NULL;
gc::InitialHeap heap = GetInitialHeap(newKind, clasp);
JSObject *obj = JSObject::create(cx, kind, heap, shape, type);
if (!obj)
return NULL;
if (newKind == SingletonObject) {
RootedObject nobj(cx, obj);
if (!JSObject::setSingletonType(cx, nobj))
return NULL;
obj = nobj;
}
/*
* This will cancel an already-running incremental GC from doing any more
* slices, and it will prevent any future incremental GCs.
*/
if (clasp->trace && !(clasp->flags & JSCLASS_IMPLEMENTS_BARRIERS))
cx->runtime()->gcIncrementalEnabled = false;
Probes::createObject(cx, obj);
return obj;
}
void
NewObjectCache::fillProto(EntryIndex entry, Class *clasp, js::TaggedProto proto,
gc::AllocKind kind, JSObject *obj)
{
JS_ASSERT_IF(proto.isObject(), !proto.toObject()->is<GlobalObject>());
JS_ASSERT(obj->getTaggedProto() == proto);
return fill(entry, clasp, proto.raw(), kind, obj);
}
JSObject *
js::NewObjectWithGivenProto(JSContext *cx, js::Class *clasp,
js::TaggedProto proto_, JSObject *parent_,
gc::AllocKind allocKind, NewObjectKind newKind)
{
Rooted<TaggedProto> proto(cx, proto_);
RootedObject parent(cx, parent_);
if (CanBeFinalizedInBackground(allocKind, clasp))
allocKind = GetBackgroundAllocKind(allocKind);
NewObjectCache &cache = cx->runtime()->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
if (proto.isObject() &&
newKind == GenericObject &&
!cx->compartment()->objectMetadataCallback &&
(!parent || parent == proto.toObject()->getParent()) &&
!proto.toObject()->is<GlobalObject>())
{
if (cache.lookupProto(clasp, proto.toObject(), allocKind, &entry)) {
JSObject *obj = cache.newObjectFromHit(cx, entry, GetInitialHeap(newKind, clasp));
if (obj)
return obj;
}
}
types::TypeObject *type = cx->compartment()->getNewType(cx, clasp, proto, NULL);
if (!type)
return NULL;
/*
* Default parent to the parent of the prototype, which was set from
* the parent of the prototype's constructor.
*/
if (!parent && proto.isObject())
parent = proto.toObject()->getParent();
RootedObject obj(cx, NewObject(cx, clasp, type, parent, allocKind, newKind));
if (!obj)
return NULL;
if (entry != -1 && !obj->hasDynamicSlots())
cache.fillProto(entry, clasp, proto, allocKind, obj);
return obj;
}
JSObject *
js::NewObjectWithClassProtoCommon(JSContext *cx, js::Class *clasp, JSObject *protoArg, JSObject *parentArg,
gc::AllocKind allocKind, NewObjectKind newKind)
{
if (protoArg)
return NewObjectWithGivenProto(cx, clasp, protoArg, parentArg, allocKind, newKind);
if (CanBeFinalizedInBackground(allocKind, clasp))
allocKind = GetBackgroundAllocKind(allocKind);
if (!parentArg)
parentArg = cx->global();
/*
* Use the object cache, except for classes without a cached proto key.
* On these objects, FindProto will do a dynamic property lookup to get
* global[className].prototype, where changes to either the className or
* prototype property would render the cached lookup incorrect. For classes
* with a proto key, the prototype created during class initialization is
* stored in an immutable slot on the global (except for ClearScope, which
* will flush the new object cache).
*/
JSProtoKey protoKey = GetClassProtoKey(clasp);
NewObjectCache &cache = cx->runtime()->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
if (parentArg->is<GlobalObject>() &&
protoKey != JSProto_Null &&
newKind == GenericObject &&
!cx->compartment()->objectMetadataCallback)
{
if (cache.lookupGlobal(clasp, &parentArg->as<GlobalObject>(), allocKind, &entry)) {
JSObject *obj = cache.newObjectFromHit(cx, entry, GetInitialHeap(newKind, clasp));
if (obj)
return obj;
}
}
RootedObject parent(cx, parentArg);
RootedObject proto(cx, protoArg);
if (!FindProto(cx, clasp, &proto))
return NULL;
types::TypeObject *type = proto->getNewType(cx, clasp);
if (!type)
return NULL;
JSObject *obj = NewObject(cx, clasp, type, parent, allocKind, newKind);
if (!obj)
return NULL;
if (entry != -1 && !obj->hasDynamicSlots())
cache.fillGlobal(entry, clasp, &parent->as<GlobalObject>(), allocKind, obj);
return obj;
}
JSObject *
js::NewObjectWithType(JSContext *cx, HandleTypeObject type, JSObject *parent, gc::AllocKind allocKind,
NewObjectKind newKind /* = GenericObject */)
{
JS_ASSERT(type->proto->hasNewType(&ObjectClass, type));
JS_ASSERT(parent);
JS_ASSERT(allocKind <= gc::FINALIZE_OBJECT_LAST);
if (CanBeFinalizedInBackground(allocKind, &ObjectClass))
allocKind = GetBackgroundAllocKind(allocKind);
NewObjectCache &cache = cx->runtime()->newObjectCache;
NewObjectCache::EntryIndex entry = -1;
if (parent == type->proto->getParent() &&
newKind == GenericObject &&
!cx->compartment()->objectMetadataCallback)
{
if (cache.lookupType(&ObjectClass, type, allocKind, &entry)) {
JSObject *obj = cache.newObjectFromHit(cx, entry, GetInitialHeap(newKind, &ObjectClass));
if (obj)
return obj;
}
}
JSObject *obj = NewObject(cx, &ObjectClass, type, parent, allocKind, newKind);
if (!obj)
return NULL;
if (entry != -1 && !obj->hasDynamicSlots())
cache.fillType(entry, &ObjectClass, type, allocKind, obj);
return obj;
}
bool
js::NewObjectScriptedCall(JSContext *cx, MutableHandleObject pobj)
{
jsbytecode *pc;
RootedScript script(cx, cx->currentScript(&pc));
gc::AllocKind allocKind = NewObjectGCKind(&ObjectClass);
NewObjectKind newKind = script
? UseNewTypeForInitializer(cx, script, pc, &ObjectClass)
: GenericObject;
RootedObject obj(cx, NewBuiltinClassInstance(cx, &ObjectClass, allocKind, newKind));
if (!obj)
return false;
if (script) {
/* Try to specialize the type of the object to the scripted call site. */
if (!types::SetInitializerObjectType(cx, script, pc, obj, newKind))
return false;
}
pobj.set(obj);
return true;
}
JSObject *
js::NewReshapedObject(JSContext *cx, HandleTypeObject type, JSObject *parent,
gc::AllocKind kind, HandleShape shape)
{
RootedObject res(cx, NewObjectWithType(cx, type, parent, kind));
if (!res)
return NULL;
if (shape->isEmptyShape())
return res;
/* Get all the ids in the object, in order. */
js::AutoIdVector ids(cx);
{
for (unsigned i = 0; i <= shape->slot(); i++) {
if (!ids.append(JSID_VOID))
return NULL;
}
Shape *nshape = shape;
while (!nshape->isEmptyShape()) {
ids[nshape->slot()] = nshape->propid();
nshape = nshape->previous();
}
}
/* Construct the new shape. */
RootedId id(cx);
RootedValue undefinedValue(cx, UndefinedValue());
for (unsigned i = 0; i < ids.length(); i++) {
id = ids[i];
if (!DefineNativeProperty(cx, res, id, undefinedValue, NULL, NULL,
JSPROP_ENUMERATE, 0, 0, DNP_SKIP_TYPE)) {
return NULL;
}
}
JS_ASSERT(!res->inDictionaryMode());
return res;
}
JSObject*
js::CreateThis(JSContext *cx, Class *newclasp, HandleObject callee)
{
RootedValue protov(cx);
if (!JSObject::getProperty(cx, callee, callee, cx->names().classPrototype, &protov))
return NULL;
JSObject *proto = protov.isObjectOrNull() ? protov.toObjectOrNull() : NULL;
JSObject *parent = callee->getParent();
gc::AllocKind kind = NewObjectGCKind(newclasp);
return NewObjectWithClassProto(cx, newclasp, proto, parent, kind);
}
static inline JSObject *
CreateThisForFunctionWithType(JSContext *cx, HandleTypeObject type, JSObject *parent,
NewObjectKind newKind)
{
if (type->newScript) {
/*
* Make an object with the type's associated finalize kind and shape,
* which reflects any properties that will definitely be added to the
* object before it is read from.
*/
gc::AllocKind kind = type->newScript->allocKind;
RootedObject res(cx, NewObjectWithType(cx, type, parent, kind, newKind));
if (!res)
return NULL;
RootedObject metadata(cx, res->getMetadata());
RootedShape shape(cx, type->newScript->shape);
JS_ALWAYS_TRUE(JSObject::setLastProperty(cx, res, shape));
if (metadata && !JSObject::setMetadata(cx, res, metadata))
return NULL;
return res;
}
gc::AllocKind allocKind = NewObjectGCKind(&ObjectClass);
return NewObjectWithType(cx, type, parent, allocKind, newKind);
}
JSObject *
js::CreateThisForFunctionWithProto(JSContext *cx, HandleObject callee, JSObject *proto,
NewObjectKind newKind /* = GenericObject */)
{
JSObject *res;
if (proto) {
RootedTypeObject type(cx, proto->getNewType(cx, &ObjectClass, &callee->as<JSFunction>()));
if (!type)
return NULL;
res = CreateThisForFunctionWithType(cx, type, callee->getParent(), newKind);
} else {
gc::AllocKind allocKind = NewObjectGCKind(&ObjectClass);
res = NewObjectWithClassProto(cx, &ObjectClass, proto, callee->getParent(), allocKind, newKind);
}
if (res && cx->typeInferenceEnabled()) {
JSScript *script = callee->as<JSFunction>().nonLazyScript();
TypeScript::SetThis(cx, script, types::Type::ObjectType(res));
}
return res;
}
JSObject *
js::CreateThisForFunction(JSContext *cx, HandleObject callee, bool newType)
{
RootedValue protov(cx);
if (!JSObject::getProperty(cx, callee, callee, cx->names().classPrototype, &protov))
return NULL;
JSObject *proto;
if (protov.isObject())
proto = &protov.toObject();
else
proto = NULL;
NewObjectKind newKind = newType ? SingletonObject : GenericObject;
JSObject *obj = CreateThisForFunctionWithProto(cx, callee, proto, newKind);
if (obj && newType) {
RootedObject nobj(cx, obj);
/* Reshape the singleton before passing it as the 'this' value. */
JSObject::clear(cx, nobj);
JSScript *calleeScript = callee->as<JSFunction>().nonLazyScript();
TypeScript::SetThis(cx, calleeScript, types::Type::ObjectType(nobj));
return nobj;
}
return obj;
}
/*
* Given pc pointing after a property accessing bytecode, return true if the
* access is "object-detecting" in the sense used by web scripts, e.g., when
* checking whether document.all is defined.
*/
static bool
Detecting(JSContext *cx, JSScript *script, jsbytecode *pc)
{
/* General case: a branch or equality op follows the access. */
JSOp op = JSOp(*pc);
if (js_CodeSpec[op].format & JOF_DETECTING)
return true;
jsbytecode *endpc = script->code + script->length;
JS_ASSERT(script->code <= pc && pc < endpc);
if (op == JSOP_NULL) {
/*
* Special case #1: handle (document.all == null). Don't sweat
* about JS1.2's revision of the equality operators here.
*/
if (++pc < endpc) {
op = JSOp(*pc);
return op == JSOP_EQ || op == JSOP_NE;
}
return false;
}
if (op == JSOP_GETGNAME || op == JSOP_NAME) {
/*
* Special case #2: handle (document.all == undefined). Don't worry
* about a local variable named |undefined| shadowing the immutable
* global binding...because, really?
*/
JSAtom *atom = script->getAtom(GET_UINT32_INDEX(pc));
if (atom == cx->names().undefined &&
(pc += js_CodeSpec[op].length) < endpc) {
op = JSOp(*pc);
return op == JSOP_EQ || op == JSOP_NE || op == JSOP_STRICTEQ || op == JSOP_STRICTNE;
}
}
return false;
}
/*
* Infer lookup flags from the currently executing bytecode, returning
* defaultFlags if a currently executing bytecode cannot be determined.
*/
unsigned
js_InferFlags(JSContext *cx, unsigned defaultFlags)
{
/*
* We intentionally want to look across compartment boundaries to correctly
* handle the case of cross-compartment property access.
*/
jsbytecode *pc;
JSScript *script = cx->currentScript(&pc, JSContext::ALLOW_CROSS_COMPARTMENT);
if (!script)
return defaultFlags;
uint32_t format = js_CodeSpec[*pc].format;
unsigned flags = 0;
if (format & JOF_SET)
flags |= JSRESOLVE_ASSIGNING;
return flags;
}
/* static */ JSBool
JSObject::nonNativeSetProperty(JSContext *cx, HandleObject obj,
HandleId id, MutableHandleValue vp, JSBool strict)
{
if (JS_UNLIKELY(obj->watched())) {
WatchpointMap *wpmap = cx->compartment()->watchpointMap;
if (wpmap && !wpmap->triggerWatchpoint(cx, obj, id, vp))
return false;
}
return obj->getOps()->setGeneric(cx, obj, id, vp, strict);
}
/* static */ JSBool
JSObject::nonNativeSetElement(JSContext *cx, HandleObject obj,
uint32_t index, MutableHandleValue vp, JSBool strict)
{
if (JS_UNLIKELY(obj->watched())) {
RootedId id(cx);
if (!IndexToId(cx, index, &id))
return false;
WatchpointMap *wpmap = cx->compartment()->watchpointMap;
if (wpmap && !wpmap->triggerWatchpoint(cx, obj, id, vp))
return false;
}
return obj->getOps()->setElement(cx, obj, index, vp, strict);
}
/* static */ bool
JSObject::deleteByValue(JSContext *cx, HandleObject obj, const Value &property, JSBool *succeeded)
{
uint32_t index;
if (IsDefinitelyIndex(property, &index))
return deleteElement(cx, obj, index, succeeded);
RootedValue propval(cx, property);
Rooted<SpecialId> sid(cx);
if (ValueIsSpecial(obj, &propval, &sid, cx))
return deleteSpecial(cx, obj, sid, succeeded);
JSAtom *name = ToAtom<CanGC>(cx, propval);
if (!name)
return false;
if (name->isIndex(&index))
return deleteElement(cx, obj, index, succeeded);
Rooted<PropertyName*> propname(cx, name->asPropertyName());
return deleteProperty(cx, obj, propname, succeeded);
}
JS_FRIEND_API(bool)
JS_CopyPropertiesFrom(JSContext *cx, JSObject *targetArg, JSObject *objArg)
{
RootedObject target(cx, targetArg);
RootedObject obj(cx, objArg);
// If we're not native, then we cannot copy properties.
JS_ASSERT(target->isNative() == obj->isNative());
if (!target->isNative())
return true;
AutoShapeVector shapes(cx);
for (Shape::Range<NoGC> r(obj->lastProperty()); !r.empty(); r.popFront()) {
if (!shapes.append(&r.front()))
return false;
}
RootedShape shape(cx);
RootedValue v(cx);
RootedId id(cx);
size_t n = shapes.length();
while (n > 0) {
shape = shapes[--n];
unsigned attrs = shape->attributes();
PropertyOp getter = shape->getter();
StrictPropertyOp setter = shape->setter();
AutoRooterGetterSetter gsRoot(cx, attrs, &getter, &setter);
if ((attrs & JSPROP_GETTER) && !cx->compartment()->wrap(cx, &getter))
return false;
if ((attrs & JSPROP_SETTER) && !cx->compartment()->wrap(cx, &setter))
return false;
v = shape->hasSlot() ? obj->getSlot(shape->slot()) : UndefinedValue();
if (!cx->compartment()->wrap(cx, &v))
return false;
id = shape->propid();
if (!JSObject::defineGeneric(cx, target, id, v, getter, setter, attrs))
return false;
}
return true;
}
static bool
CopySlots(JSContext *cx, HandleObject from, HandleObject to)
{
JS_ASSERT(!from->isNative() && !to->isNative());
JS_ASSERT(from->getClass() == to->getClass());
size_t n = 0;
if (from->isWrapper() &&
(Wrapper::wrapperHandler(from)->flags() &
Wrapper::CROSS_COMPARTMENT)) {
to->setSlot(0, from->getSlot(0));
to->setSlot(1, from->getSlot(1));
n = 2;
}
size_t span = JSCLASS_RESERVED_SLOTS(from->getClass());
RootedValue v(cx);
for (; n < span; ++n) {
v = from->getSlot(n);
if (!cx->compartment()->wrap(cx, &v))
return false;
to->setSlot(n, v);
}
return true;
}
JSObject *
js::CloneObject(JSContext *cx, HandleObject obj, Handle<js::TaggedProto> proto, HandleObject parent)
{
if (!obj->isNative() && !obj->isProxy()) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_CANT_CLONE_OBJECT);
return NULL;
}
RootedObject clone(cx, NewObjectWithGivenProto(cx, obj->getClass(), proto, parent));
if (!clone)
return NULL;
if (obj->isNative()) {
if (clone->is<JSFunction>() && (obj->compartment() != clone->compartment())) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_CANT_CLONE_OBJECT);
return NULL;
}
if (obj->hasPrivate())
clone->setPrivate(obj->getPrivate());
} else {
JS_ASSERT(obj->isProxy());
if (!CopySlots(cx, obj, clone))
return NULL;
}
return clone;
}
JSObject *
js::CloneObjectLiteral(JSContext *cx, HandleObject parent, HandleObject srcObj)
{
Rooted<TypeObject*> typeObj(cx);
typeObj = cx->global()->getOrCreateObjectPrototype(cx)->getNewType(cx, &ObjectClass);
JS_ASSERT(srcObj->getClass() == &ObjectClass);
AllocKind kind = GetBackgroundAllocKind(GuessObjectGCKind(srcObj->numFixedSlots()));
JS_ASSERT_IF(srcObj->isTenured(), kind == srcObj->tenuredGetAllocKind());
RootedShape shape(cx, srcObj->lastProperty());
return NewReshapedObject(cx, typeObj, parent, kind, shape);
}
struct JSObject::TradeGutsReserved {
Vector<Value> avals;
Vector<Value> bvals;
int newafixed;
int newbfixed;
RootedShape newashape;
RootedShape newbshape;
HeapSlot *newaslots;
HeapSlot *newbslots;
TradeGutsReserved(JSContext *cx)
: avals(cx), bvals(cx),
newafixed(0), newbfixed(0),
newashape(cx), newbshape(cx),
newaslots(NULL), newbslots(NULL)
{}
~TradeGutsReserved()
{
if (newaslots)
js_free(newaslots);
if (newbslots)
js_free(newbslots);
}
};
bool
JSObject::ReserveForTradeGuts(JSContext *cx, JSObject *aArg, JSObject *bArg,
TradeGutsReserved &reserved)
{
/*
* Avoid GC in here to avoid confusing the tracing code with our
* intermediate state.
*/
AutoSuppressGC suppress(cx);
RootedObject a(cx, aArg);
RootedObject b(cx, bArg);
JS_ASSERT(a->compartment() == b->compartment());
AutoCompartment ac(cx, a);
/*
* When performing multiple swaps between objects which may have different
* numbers of fixed slots, we reserve all space ahead of time so that the
* swaps can be performed infallibly.
*/
/*
* Swap prototypes and classes on the two objects, so that TradeGuts can
* preserve the types of the two objects.
*/
Class *aClass = a->getClass();
Class *bClass = b->getClass();
Rooted<TaggedProto> aProto(cx, a->getTaggedProto());
Rooted<TaggedProto> bProto(cx, b->getTaggedProto());
if (!SetClassAndProto(cx, a, bClass, bProto, false))
return false;
if (!SetClassAndProto(cx, b, aClass, aProto, false))
return false;
if (a->tenuredSizeOfThis() == b->tenuredSizeOfThis())
return true;
/*
* If either object is native, it needs a new shape to preserve the
* invariant that objects with the same shape have the same number of
* inline slots. The fixed slots will be updated in place during TradeGuts.
* Non-native objects need to be reshaped according to the new count.
*/
if (a->isNative()) {
if (!a->generateOwnShape(cx))
return false;
} else {
reserved.newbshape = EmptyShape::getInitialShape(cx, aClass, aProto, a->getParent(), a->getMetadata(),
b->tenuredGetAllocKind());
if (!reserved.newbshape)
return false;
}
if (b->isNative()) {
if (!b->generateOwnShape(cx))
return false;
} else {
reserved.newashape = EmptyShape::getInitialShape(cx, bClass, bProto, b->getParent(), b->getMetadata(),
a->tenuredGetAllocKind());
if (!reserved.newashape)
return false;
}
/* The avals/bvals vectors hold all original values from the objects. */
if (!reserved.avals.reserve(a->slotSpan()))
return false;
if (!reserved.bvals.reserve(b->slotSpan()))
return false;
/*
* The newafixed/newbfixed hold the number of fixed slots in the objects
* after the swap. Adjust these counts according to whether the objects
* use their last fixed slot for storing private data.
*/
reserved.newafixed = a->numFixedSlots();
reserved.newbfixed = b->numFixedSlots();
if (aClass->hasPrivate()) {
reserved.newafixed++;
reserved.newbfixed--;
}
if (bClass->hasPrivate()) {
reserved.newbfixed++;
reserved.newafixed--;
}
JS_ASSERT(reserved.newafixed >= 0);
JS_ASSERT(reserved.newbfixed >= 0);
/*
* The newaslots/newbslots arrays hold any dynamic slots for the objects
* if they do not have enough fixed slots to accomodate the slots in the
* other object.
*/
unsigned adynamic = dynamicSlotsCount(reserved.newafixed, b->slotSpan());
unsigned bdynamic = dynamicSlotsCount(reserved.newbfixed, a->slotSpan());
if (adynamic) {
reserved.newaslots = cx->pod_malloc<HeapSlot>(adynamic);
if (!reserved.newaslots)
return false;
Debug_SetSlotRangeToCrashOnTouch(reserved.newaslots, adynamic);
}
if (bdynamic) {
reserved.newbslots = cx->pod_malloc<HeapSlot>(bdynamic);
if (!reserved.newbslots)
return false;
Debug_SetSlotRangeToCrashOnTouch(reserved.newbslots, bdynamic);
}
return true;
}
void
JSObject::TradeGuts(JSContext *cx, JSObject *a, JSObject *b, TradeGutsReserved &reserved)
{
JS_ASSERT(a->compartment() == b->compartment());
JS_ASSERT(a->is<JSFunction>() == b->is<JSFunction>());
/*
* Swap the object's types, to restore their initial type information.
* The prototypes and classes of the objects were swapped in ReserveForTradeGuts.
*/
TypeObject *tmp = a->type_;
a->type_ = b->type_;
b->type_ = tmp;
/* Don't try to swap a JSFunction for a plain function JSObject. */
JS_ASSERT_IF(a->is<JSFunction>(), a->tenuredSizeOfThis() == b->tenuredSizeOfThis());
/*
* Regexp guts are more complicated -- we would need to migrate the
* refcounted JIT code blob for them across compartments instead of just
* swapping guts.
*/
JS_ASSERT(!a->is<RegExpObject>() && !b->is<RegExpObject>());
/* Arrays can use their fixed storage for elements. */
JS_ASSERT(!a->isArray() && !b->isArray());
/*
* Callers should not try to swap ArrayBuffer objects,
* these use a different slot representation from other objects.
*/
JS_ASSERT(!a->is<ArrayBufferObject>() && !b->is<ArrayBufferObject>());
/* Trade the guts of the objects. */
const size_t size = a->tenuredSizeOfThis();
if (size == b->tenuredSizeOfThis()) {
/*
* If the objects are the same size, then we make no assumptions about
* whether they have dynamically allocated slots and instead just copy
* them over wholesale.
*/
char tmp[tl::Max<sizeof(JSFunction), sizeof(JSObject_Slots16)>::result];
JS_ASSERT(size <= sizeof(tmp));
js_memcpy(tmp, a, size);
js_memcpy(a, b, size);
js_memcpy(b, tmp, size);
#ifdef JSGC_GENERATIONAL
/*
* Trigger post barriers for fixed slots. JSObject bits are barriered
* below, in common with the other case.
*/
for (size_t i = 0; i < a->numFixedSlots(); ++i) {
HeapSlot::writeBarrierPost(cx->runtime(), a, HeapSlot::Slot, i);
HeapSlot::writeBarrierPost(cx->runtime(), b, HeapSlot::Slot, i);
}
#endif
} else {
/*
* If the objects are of differing sizes, use the space we reserved
* earlier to save the slots from each object and then copy them into
* the new layout for the other object.
*/
uint32_t acap = a->slotSpan();
uint32_t bcap = b->slotSpan();
for (size_t i = 0; i < acap; i++)
reserved.avals.infallibleAppend(a->getSlot(i));
for (size_t i = 0; i < bcap; i++)
reserved.bvals.infallibleAppend(b->getSlot(i));
/* Done with the dynamic slots. */
if (a->hasDynamicSlots())
js_free(a->slots);
if (b->hasDynamicSlots())
js_free(b->slots);
void *apriv = a->hasPrivate() ? a->getPrivate() : NULL;
void *bpriv = b->hasPrivate() ? b->getPrivate() : NULL;
char tmp[sizeof(JSObject)];
js_memcpy(&tmp, a, sizeof tmp);
js_memcpy(a, b, sizeof tmp);
js_memcpy(b, &tmp, sizeof tmp);
if (a->isNative())
a->shape_->setNumFixedSlots(reserved.newafixed);
else
a->shape_ = reserved.newashape;
a->slots = reserved.newaslots;
a->initSlotRange(0, reserved.bvals.begin(), bcap);
if (a->hasPrivate())
a->initPrivate(bpriv);
if (b->isNative())
b->shape_->setNumFixedSlots(reserved.newbfixed);
else
b->shape_ = reserved.newbshape;
b->slots = reserved.newbslots;
b->initSlotRange(0, reserved.avals.begin(), acap);
if (b->hasPrivate())
b->initPrivate(apriv);
/* Make sure the destructor for reserved doesn't free the slots. */
reserved.newaslots = NULL;
reserved.newbslots = NULL;
}
#ifdef JSGC_GENERATIONAL
Shape::writeBarrierPost(a->shape_, &a->shape_);
Shape::writeBarrierPost(b->shape_, &b->shape_);
types::TypeObject::writeBarrierPost(a->type_, &a->type_);
types::TypeObject::writeBarrierPost(b->type_, &b->type_);
#endif
if (a->inDictionaryMode())
a->lastProperty()->listp = &a->shape_;
if (b->inDictionaryMode())
b->lastProperty()->listp = &b->shape_;
#ifdef JSGC_INCREMENTAL
/*
* 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.
* We don't do the barrier before TradeGuts because ReserveForTradeGuts
* makes changes to the objects that might confuse the tracing code.
*/
JS::Zone *zone = a->zone();
if (zone->needsBarrier()) {
MarkChildren(zone->barrierTracer(), a);
MarkChildren(zone->barrierTracer(), b);
}
#endif
}
/* Use this method with extreme caution. It trades the guts of two objects. */
bool
JSObject::swap(JSContext *cx, HandleObject a, HandleObject b)
{
AutoMarkInDeadZone adc1(a->zone());
AutoMarkInDeadZone adc2(b->zone());
// Ensure swap doesn't cause a finalizer to not be run.
JS_ASSERT(IsBackgroundFinalized(a->tenuredGetAllocKind()) ==
IsBackgroundFinalized(b->tenuredGetAllocKind()));
JS_ASSERT(a->compartment() == b->compartment());
unsigned r = NotifyGCPreSwap(a, b);
TradeGutsReserved reserved(cx);
if (!ReserveForTradeGuts(cx, a, b, reserved)) {
NotifyGCPostSwap(b, a, r);
return false;
}
TradeGuts(cx, a, b, reserved);
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.
*/
JS_ASSERT(obj->is<GlobalObject>());
JS_ASSERT(obj->isNative());
if (!obj->nativeLookup(cx, id)) {
uint32_t slot = 2 * JSProto_LIMIT + key;
obj->setReservedSlot(slot, v);
if (!JSObject::addProperty(cx, obj, id, JS_PropertyStub, JS_StrictPropertyStub, slot, attrs, 0, 0))
return false;
AddTypePropertyId(cx, obj, id, v);
named = true;
return true;
}
}
named = JSObject::defineGeneric(cx, obj, id,
v, JS_PropertyStub, JS_StrictPropertyStub, attrs);
return named;
}
static void
SetClassObject(JSObject *obj, JSProtoKey key, JSObject *cobj, JSObject *proto)
{
JS_ASSERT(!obj->getParent());
if (!obj->is<GlobalObject>())
return;
obj->setReservedSlot(key, ObjectOrNullValue(cobj));
obj->setReservedSlot(JSProto_LIMIT + key, ObjectOrNullValue(proto));
}
static void
ClearClassObject(JSObject *obj, JSProtoKey key)
{
JS_ASSERT(!obj->getParent());
if (!obj->is<GlobalObject>())
return;
obj->setSlot(key, UndefinedValue());
obj->setSlot(JSProto_LIMIT + key, UndefinedValue());
}
JSObject *
js::DefineConstructorAndPrototype(JSContext *cx, HandleObject obj, JSProtoKey key, HandleAtom atom,
JSObject *protoProto, Class *clasp,
Native constructor, unsigned nargs,
const JSPropertySpec *ps, const JSFunctionSpec *fs,
const JSPropertySpec *static_ps, const JSFunctionSpec *static_fs,
JSObject **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 parents the prototype object to the global and because
* it uses WithProto::Given. FIXME: Undo dependencies on this parentage
* [which already needs to happen for bug 638316], figure out nicer
* semantics for null-protoProto, and use createBlankPrototype.)
*/
RootedObject proto(cx, NewObjectWithClassProto(cx, clasp, protoProto, obj, SingletonObject));
if (!proto)
return NULL;
/* After this point, control must exit via label bad or out. */
RootedObject 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 {
/*
* Create the constructor, not using GlobalObject::createConstructor
* because the constructor currently must have |obj| as its parent.
* (FIXME: remove this dependency on the exact identity of the parent,
* perhaps as part of bug 638316.)
*/
RootedFunction fun(cx, NewFunction(cx, NullPtr(), constructor, nargs,
JSFunction::NATIVE_CTOR, obj, atom, ctorKind));
if (!fun)
goto bad;
/*
* Set the class object early for standard class constructors. Type
* inference may need to access these, and js_GetClassPrototype 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 (!DefinePropertiesAndBrand(cx, proto, ps, fs) ||
(ctor != proto && !DefinePropertiesAndBrand(cx, ctor, static_ps, static_fs)))
{
goto bad;
}
if (clasp->flags & (JSCLASS_FREEZE_PROTO|JSCLASS_FREEZE_CTOR)) {
JS_ASSERT_IF(ctor == proto, !(clasp->flags & JSCLASS_FREEZE_CTOR));
if (proto && (clasp->flags & JSCLASS_FREEZE_PROTO) && !JSObject::freeze(cx, proto))
goto bad;
if (ctor && (clasp->flags & JSCLASS_FREEZE_CTOR) && !JSObject::freeze(cx, ctor))
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) {
JSBool succeeded;
JSObject::deleteByValue(cx, obj, StringValue(atom), &succeeded);
}
if (cached)
ClearClassObject(obj, key);
return NULL;
}
/*
* Lazy standard classes need a way to indicate if they have been initialized.
* Otherwise, when we delete them, we might accidentally recreate them via a
* lazy initialization. We use the presence of a ctor or proto in the
* global object's slot to indicate that they've been constructed, but this only
* works for classes which have a proto and ctor. Classes which don't have one
* can call MarkStandardClassInitializedNoProto(), and we can always check
* whether a class is initialized by calling IsStandardClassResolved().
*/
bool
js::IsStandardClassResolved(JSObject *obj, js::Class *clasp)
{
JSProtoKey key = JSCLASS_CACHED_PROTO_KEY(clasp);
/* If the constructor is undefined, then it hasn't been initialized. */
return (obj->getReservedSlot(key) != UndefinedValue());
}
void
js::MarkStandardClassInitializedNoProto(JSObject *obj, js::Class *clasp)
{
JSProtoKey key = JSCLASS_CACHED_PROTO_KEY(clasp);
/*
* We use True so that it's obvious what we're doing (instead of, say,
* Null, which might be miscontrued as an error in setting Undefined).
*/
if (obj->getReservedSlot(key) == UndefinedValue())
obj->setSlot(key, BooleanValue(true));
}
JSObject *
js_InitClass(JSContext *cx, HandleObject obj, JSObject *protoProto_,
Class *clasp, Native constructor, unsigned nargs,
const JSPropertySpec *ps, const JSFunctionSpec *fs,
const JSPropertySpec *static_ps, const JSFunctionSpec *static_fs,
JSObject **ctorp, AllocKind ctorKind)
{
RootedObject protoProto(cx, protoProto_);
RootedAtom atom(cx, Atomize(cx, clasp->name, strlen(clasp->name)));
if (!atom)
return NULL;
/*
* 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 the Object prototype object. The engine's internal uses
* of js_InitClass depend on this nicety. Note that in
* js_InitFunctionAndObjectClasses, we specially hack the resolving table
* and then depend on js_GetClassPrototype here leaving protoProto NULL and
* returning true.
*/
JSProtoKey key = JSCLASS_CACHED_PROTO_KEY(clasp);
if (key != JSProto_Null &&
!protoProto &&
!js_GetClassPrototype(cx, JSProto_Object, &protoProto)) {
return NULL;
}
return DefineConstructorAndPrototype(cx, obj, key, atom, protoProto, clasp, constructor, nargs,
ps, fs, static_ps, static_fs, ctorp, ctorKind);
}
/* static */ inline bool
JSObject::updateSlotsForSpan(JSContext *cx, HandleObject obj, size_t oldSpan, size_t newSpan)
{
JS_ASSERT(oldSpan != newSpan);
size_t oldCount = dynamicSlotsCount(obj->numFixedSlots(), oldSpan);
size_t newCount = dynamicSlotsCount(obj->numFixedSlots(), newSpan);
if (oldSpan < newSpan) {
if (oldCount < newCount && !JSObject::growSlots(cx, obj, oldCount, newCount))
return false;
if (newSpan == oldSpan + 1)
obj->initSlotUnchecked(oldSpan, UndefinedValue());
else
obj->initializeSlotRange(oldSpan, newSpan - oldSpan);
} else {
/* Trigger write barriers on the old slots before reallocating. */
obj->prepareSlotRangeForOverwrite(newSpan, oldSpan);
obj->invalidateSlotRange(newSpan, oldSpan - newSpan);
if (oldCount > newCount)
JSObject::shrinkSlots(cx, obj, oldCount, newCount);
}
return true;
}
/* static */ bool
JSObject::setLastProperty(JSContext *cx, HandleObject obj, HandleShape shape)
{
JS_ASSERT(!obj->inDictionaryMode());
JS_ASSERT(!shape->inDictionary());
JS_ASSERT(shape->compartment() == obj->compartment());
JS_ASSERT(shape->numFixedSlots() == obj->numFixedSlots());
size_t oldSpan = obj->lastProperty()->slotSpan();
size_t newSpan = shape->slotSpan();
if (oldSpan == newSpan) {
obj->shape_ = shape;
return true;
}
if (!updateSlotsForSpan(cx, obj, oldSpan, newSpan))
return false;
obj->shape_ = shape;
return true;
}
/* static */ bool
JSObject::setSlotSpan(JSContext *cx, HandleObject obj, uint32_t span)
{
JS_ASSERT(obj->inDictionaryMode());
size_t oldSpan = obj->lastProperty()->base()->slotSpan();
if (oldSpan == span)
return true;
if (!JSObject::updateSlotsForSpan(cx, obj, oldSpan, span))
return false;
obj->lastProperty()->base()->setSlotSpan(span);
return true;
}
static HeapSlot *
AllocateSlots(JSContext *cx, JSObject *obj, uint32_t nslots)
{
#ifdef JSGC_GENERATIONAL
return cx->runtime()->gcNursery.allocateSlots(cx, obj, nslots);
#else
return cx->pod_malloc<HeapSlot>(nslots);
#endif
}
static HeapSlot *
ReallocateSlots(JSContext *cx, JSObject *obj, HeapSlot *oldSlots,
uint32_t oldCount, uint32_t newCount)
{
#ifdef JSGC_GENERATIONAL
return cx->runtime()->gcNursery.reallocateSlots(cx, obj, oldSlots, oldCount, newCount);
#else
return (HeapSlot *)cx->realloc_(oldSlots, oldCount * sizeof(HeapSlot),
newCount * sizeof(HeapSlot));
#endif
}
/* static */ bool
JSObject::growSlots(JSContext *cx, HandleObject obj, uint32_t oldCount, uint32_t newCount)
{
JS_ASSERT(newCount > oldCount);
JS_ASSERT(newCount >= SLOT_CAPACITY_MIN);
/*
* Slot capacities are determined by the span of allocated objects. Due to
* the limited number of bits to store shape slots, object growth is
* throttled well before the slot capacity can overflow.
*/
JS_ASSERT(newCount < NELEMENTS_LIMIT);
/*
* If we are allocating slots for an object whose type is always created
* by calling 'new' on a particular script, bump the GC kind for that
* type to give these objects a larger number of fixed slots when future
* objects are constructed.
*/
if (!obj->hasLazyType() && !oldCount && obj->type()->newScript) {
gc::AllocKind kind = obj->type()->newScript->allocKind;
uint32_t newScriptSlots = gc::GetGCKindSlots(kind);
if (newScriptSlots == obj->numFixedSlots() && gc::TryIncrementAllocKind(&kind)) {
AutoEnterAnalysis enter(cx);
Rooted<TypeObject*> typeObj(cx, obj->type());
RootedShape shape(cx, typeObj->newScript->shape);
JSObject *reshapedObj = NewReshapedObject(cx, typeObj, obj->getParent(), kind, shape);
if (!reshapedObj)
return false;
typeObj->newScript->allocKind = kind;
typeObj->newScript->shape = reshapedObj->lastProperty();
typeObj->markStateChange(cx);
}
}
if (!oldCount) {
obj->slots = AllocateSlots(cx, obj, newCount);
if (!obj->slots)
return false;
Debug_SetSlotRangeToCrashOnTouch(obj->slots, newCount);
return true;
}
HeapSlot *newslots = ReallocateSlots(cx, obj, obj->slots, oldCount, newCount);
if (!newslots)
return false; /* Leave slots at its old size. */
bool changed = obj->slots != newslots;
obj->slots = newslots;
Debug_SetSlotRangeToCrashOnTouch(obj->slots + oldCount, newCount - oldCount);
/* Changes in the slots of global objects can trigger recompilation. */
if (changed && obj->is<GlobalObject>())
types::MarkObjectStateChange(cx, obj);
return true;
}
static void
FreeSlots(JSContext *cx, HeapSlot *slots)
{
#ifdef JSGC_GENERATIONAL
if (!cx->runtime()->gcNursery.isInside(slots))
#endif
js_free(slots);
}
/* static */ void
JSObject::shrinkSlots(JSContext *cx, HandleObject obj, uint32_t oldCount, uint32_t newCount)
{
JS_ASSERT(newCount < oldCount);
/*
* Refuse to shrink slots for call objects. This only happens in a very
* obscure situation (deleting names introduced by a direct 'eval') and
* allowing the slots pointer to change may require updating pointers in
* the function's active args/vars information.
*/
if (obj->is<CallObject>())
return;
if (newCount == 0) {
FreeSlots(cx, obj->slots);
obj->slots = NULL;
return;
}
JS_ASSERT(newCount >= SLOT_CAPACITY_MIN);
HeapSlot *newslots = ReallocateSlots(cx, obj, obj->slots, oldCount, newCount);
if (!newslots)
return; /* Leave slots at its old size. */
bool changed = obj->slots != newslots;
obj->slots = newslots;
/* Watch for changes in global object slots, as for growSlots. */
if (changed && obj->is<GlobalObject>())
types::MarkObjectStateChange(cx, obj);
}
/* static */ bool
JSObject::sparsifyDenseElement(JSContext *cx, HandleObject obj, uint32_t index)
{
RootedValue value(cx, obj->getDenseElement(index));
JS_ASSERT(!value.isMagic(JS_ELEMENTS_HOLE));
JSObject::removeDenseElementForSparseIndex(cx, obj, index);
uint32_t slot = obj->slotSpan();
if (!obj->addDataProperty(cx, INT_TO_JSID(index), slot, JSPROP_ENUMERATE)) {
obj->setDenseElement(index, value);
return false;
}
JS_ASSERT(slot == obj->slotSpan() - 1);
obj->initSlot(slot, value);
return true;
}
/* static */ bool
JSObject::sparsifyDenseElements(JSContext *cx, HandleObject obj)
{
uint32_t initialized = obj->getDenseInitializedLength();
/* Create new properties with the value of non-hole dense elements. */
for (uint32_t i = 0; i < initialized; i++) {
if (obj->getDenseElement(i).isMagic(JS_ELEMENTS_HOLE))
continue;
if (!sparsifyDenseElement(cx, obj, i))
return false;
}
if (initialized)
obj->setDenseInitializedLength(0);
/*
* Reduce storage for dense elements which are now holes. Explicitly mark
* the elements capacity as zero, so that any attempts to add dense
* elements will be caught in ensureDenseElements.
*/
if (obj->getDenseCapacity()) {
obj->shrinkElements(cx, 0);
obj->getElementsHeader()->capacity = 0;
}
return true;
}
bool
JSObject::willBeSparseElements(uint32_t requiredCapacity, uint32_t newElementsHint)
{
JS_ASSERT(isNative());
JS_ASSERT(requiredCapacity > MIN_SPARSE_INDEX);
uint32_t cap = getDenseCapacity();
JS_ASSERT(requiredCapacity >= cap);
if (requiredCapacity >= NELEMENTS_LIMIT)
return true;
uint32_t minimalDenseCount = requiredCapacity / SPARSE_DENSITY_RATIO;
if (newElementsHint >= minimalDenseCount)
return false;
minimalDenseCount -= newElementsHint;
if (minimalDenseCount > cap)
return true;
uint32_t len = getDenseInitializedLength();
const Value *elems = getDenseElements();
for (uint32_t i = 0; i < len; i++) {
if (!elems[i].isMagic(JS_ELEMENTS_HOLE) && !--minimalDenseCount)
return false;
}
return true;
}
/* static */ JSObject::EnsureDenseResult
JSObject::maybeDensifySparseElements(JSContext *cx, HandleObject obj)
{
/*
* Wait until after the object goes into dictionary mode, which must happen
* when sparsely packing any array with more than MIN_SPARSE_INDEX elements
* (see PropertyTree::MAX_HEIGHT).
*/
if (!obj->inDictionaryMode())
return ED_SPARSE;
/*
* Only measure the number of indexed properties every log(n) times when
* populating the object.
*/
uint32_t slotSpan = obj->slotSpan();
if (slotSpan != RoundUpPow2(slotSpan))
return ED_SPARSE;
/* Watch for conditions under which an object's elements cannot be dense. */
if (!obj->isExtensible() || obj->watched())
return ED_SPARSE;
/*
* The indexes in the object need to be sufficiently dense before they can
* be converted to dense mode.
*/
uint32_t numDenseElements = 0;
uint32_t newInitializedLength = 0;
RootedShape shape(cx, obj->lastProperty());
while (!shape->isEmptyShape()) {
uint32_t index;
if (js_IdIsIndex(shape->propid(), &index)) {
if (shape->attributes() == JSPROP_ENUMERATE &&
shape->hasDefaultGetter() &&
shape->hasDefaultSetter())
{
numDenseElements++;
newInitializedLength = Max(newInitializedLength, index + 1);
} else {
/*
* For simplicity, only densify the object if all indexed
* properties can be converted to dense elements.
*/
return ED_SPARSE;
}
}
shape = shape->previous();
}
if (numDenseElements * SPARSE_DENSITY_RATIO < newInitializedLength)
return ED_SPARSE;
if (newInitializedLength >= NELEMENTS_LIMIT)
return ED_SPARSE;
/*
* This object meets all necessary restrictions, convert all indexed
* properties into dense elements.
*/
if (newInitializedLength > obj->getDenseCapacity()) {
if (!obj->growElements(cx, newInitializedLength))
return ED_FAILED;
}
obj->ensureDenseInitializedLength(cx, newInitializedLength, 0);
RootedValue value(cx);
shape = obj->lastProperty();
while (!shape->isEmptyShape()) {
jsid id = shape->propid();
uint32_t index;
if (js_IdIsIndex(id, &index)) {
value = obj->getSlot(shape->slot());
/*
* When removing a property from a dictionary, the specified
* property will be removed from the dictionary list and the
* last property will then be changed due to reshaping the object.
* Compute the next shape in the traverse, watching for such
* removals from the list.
*/
if (shape != obj->lastProperty()) {
shape = shape->previous();
if (!obj->removeProperty(cx, id))
return ED_FAILED;
} else {
if (!obj->removeProperty(cx, id))
return ED_FAILED;
shape = obj->lastProperty();
}
obj->setDenseElement(index, value);
} else {
shape = shape->previous();
}
}
/*
* All indexed properties on the object are now dense, clear the indexed
* flag so that we will not start using sparse indexes again if we need
* to grow the object.
*/
if (!obj->clearFlag(cx, BaseShape::INDEXED))
return ED_FAILED;
return ED_OK;
}
ObjectElements *
AllocateElements(ThreadSafeContext *tcx, JSObject *obj, uint32_t nelems)
{
#ifdef JSGC_GENERATIONAL
if (tcx->isJSContext()) {
JSContext *cx = tcx->asJSContext();
return cx->runtime()->gcNursery.allocateElements(cx, obj, nelems);
}
#endif
return static_cast<js::ObjectElements *>(tcx->malloc_(nelems * sizeof(HeapValue)));
}
ObjectElements *
ReallocateElements(ThreadSafeContext *tcx, JSObject *obj, ObjectElements *oldHeader,
uint32_t oldCount, uint32_t newCount)
{
#ifdef JSGC_GENERATIONAL
if (tcx->isJSContext()) {
JSContext *cx = tcx->asJSContext();
return cx->runtime()->gcNursery.reallocateElements(cx, obj, oldHeader, oldCount, newCount);
}
#endif
return static_cast<js::ObjectElements *>(tcx->realloc_(oldHeader, oldCount * sizeof(HeapSlot),
newCount * sizeof(HeapSlot)));
}
bool
JSObject::growElements(ThreadSafeContext *tcx, uint32_t newcap)
{
JS_ASSERT(isExtensible());
JS_ASSERT_IF(isArray() && !arrayLengthIsWritable(),
newcap <= getArrayLength());
/*
* When an object with CAPACITY_DOUBLING_MAX or fewer elements needs to
* grow, double its capacity, to add N elements in amortized O(N) time.
*
* Above this limit, grow by 12.5% each time. Speed is still amortized
* O(N), with a higher constant factor, and we waste less space.
*/
static const size_t CAPACITY_DOUBLING_MAX = 1024 * 1024;
static const size_t CAPACITY_CHUNK = CAPACITY_DOUBLING_MAX / sizeof(Value);
uint32_t oldcap = getDenseCapacity();
JS_ASSERT(oldcap <= newcap);
uint32_t nextsize = (oldcap <= CAPACITY_DOUBLING_MAX)
? oldcap * 2
: oldcap + (oldcap >> 3);
uint32_t actualCapacity;
if (isArray() && !arrayLengthIsWritable()) {
// Preserve the |capacity <= length| invariant for arrays with
// non-writable length. See also js::ArraySetLength which initially
// enforces this requirement.
actualCapacity = newcap;
} else {
actualCapacity = Max(newcap, nextsize);
if (actualCapacity >= CAPACITY_CHUNK)
actualCapacity = JS_ROUNDUP(actualCapacity, CAPACITY_CHUNK);
else if (actualCapacity < SLOT_CAPACITY_MIN)
actualCapacity = SLOT_CAPACITY_MIN;
/* Don't let nelements get close to wrapping around uint32_t. */
if (actualCapacity >= NELEMENTS_LIMIT || actualCapacity < oldcap || actualCapacity < newcap)
return false;
}