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jsiter.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/. */
/* JavaScript iterators. */
#include "jsiter.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/PodOperations.h"
#include "mozilla/Util.h"
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsgc.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsproxy.h"
#include "jsscript.h"
#include "jstypes.h"
#include "jsutil.h"
#include "ds/Sort.h"
#include "gc/Marking.h"
#include "vm/GeneratorObject.h"
#include "vm/GlobalObject.h"
#include "vm/Interpreter.h"
#include "vm/Shape.h"
#include "vm/StopIterationObject.h"
#include "jsinferinlines.h"
#include "jsobjinlines.h"
#include "builtin/Iterator-inl.h"
#include "vm/Stack-inl.h"
#include "vm/String-inl.h"
using namespace js;
using namespace js::gc;
using mozilla::ArrayLength;
#ifdef JS_MORE_DETERMINISTIC
using mozilla::PodCopy;
#endif
using mozilla::PodZero;
typedef Rooted<PropertyIteratorObject*> RootedPropertyIteratorObject;
static const gc::AllocKind ITERATOR_FINALIZE_KIND = gc::FINALIZE_OBJECT2_BACKGROUND;
void
NativeIterator::mark(JSTracer *trc)
{
for (HeapPtr<JSFlatString> *str = begin(); str < end(); str++)
MarkString(trc, str, "prop");
if (obj)
MarkObject(trc, &obj, "obj");
// The SuppressDeletedPropertyHelper loop can GC, so make sure that if the
// GC removes any elements from the list, it won't remove this one.
if (iterObj_)
MarkObjectUnbarriered(trc, &iterObj_, "iterObj");
}
struct IdHashPolicy {
typedef jsid Lookup;
static HashNumber hash(jsid id) {
return JSID_BITS(id);
}
static bool match(jsid id1, jsid id2) {
return id1 == id2;
}
};
typedef HashSet<jsid, IdHashPolicy> IdSet;
static inline bool
NewKeyValuePair(JSContext *cx, jsid id, const Value &val, MutableHandleValue rval)
{
Value vec[2] = { IdToValue(id), val };
AutoArrayRooter tvr(cx, ArrayLength(vec), vec);
JSObject *aobj = NewDenseCopiedArray(cx, 2, vec);
if (!aobj)
return false;
rval.setObject(*aobj);
return true;
}
static inline bool
Enumerate(JSContext *cx, HandleObject pobj, jsid id,
bool enumerable, unsigned flags, IdSet& ht, AutoIdVector *props)
{
/*
* We implement __proto__ using a property on |Object.prototype|, but
* because __proto__ is highly deserving of removal, we don't want it to
* show up in property enumeration, even if only for |Object.prototype|
* (think introspection by Prototype-like frameworks that add methods to
* the built-in prototypes). So exclude __proto__ if the object where the
* property was found has no [[Prototype]] and might be |Object.prototype|.
*/
if (JS_UNLIKELY(!pobj->getTaggedProto().isObject() && JSID_IS_ATOM(id, cx->names().proto)))
return true;
if (!(flags & JSITER_OWNONLY) || pobj->is<ProxyObject>() || pobj->getOps()->enumerate) {
/* If we've already seen this, we definitely won't add it. */
IdSet::AddPtr p = ht.lookupForAdd(id);
if (JS_UNLIKELY(!!p))
return true;
/*
* It's not necessary to add properties to the hash table at the end of
* the prototype chain, but custom enumeration behaviors might return
* duplicated properties, so always add in such cases.
*/
if ((pobj->is<ProxyObject>() || pobj->getProto() || pobj->getOps()->enumerate) && !ht.add(p, id))
return false;
}
if (enumerable || (flags & JSITER_HIDDEN))
return props->append(id);
return true;
}
static bool
EnumerateNativeProperties(JSContext *cx, HandleObject pobj, unsigned flags, IdSet &ht,
AutoIdVector *props)
{
/* Collect any elements from this object. */
size_t initlen = pobj->getDenseInitializedLength();
const Value *vp = pobj->getDenseElements();
for (size_t i = 0; i < initlen; ++i, ++vp) {
if (!vp->isMagic(JS_ELEMENTS_HOLE)) {
/* Dense arrays never get so large that i would not fit into an integer id. */
if (!Enumerate(cx, pobj, INT_TO_JSID(i), true, flags, ht, props))
return false;
}
}
size_t initialLength = props->length();
/* Collect all unique properties from this object's scope. */
Shape::Range<NoGC> r(pobj->lastProperty());
for (; !r.empty(); r.popFront()) {
Shape &shape = r.front();
if (!Enumerate(cx, pobj, shape.propid(), shape.enumerable(), flags, ht, props))
return false;
}
::Reverse(props->begin() + initialLength, props->end());
return true;
}
#ifdef JS_MORE_DETERMINISTIC
struct SortComparatorIds
{
JSContext *const cx;
SortComparatorIds(JSContext *cx)
: cx(cx) {}
bool operator()(jsid a, jsid b, bool *lessOrEqualp)
{
/* Pick an arbitrary total order on jsids that is stable across executions. */
RootedString astr(cx, IdToString(cx, a));
if (!astr)
return false;
RootedString bstr(cx, IdToString(cx, b));
if (!bstr)
return false;
int32_t result;
if (!CompareStrings(cx, astr, bstr, &result))
return false;
*lessOrEqualp = (result <= 0);
return true;
}
};
#endif /* JS_MORE_DETERMINISTIC */
static bool
Snapshot(JSContext *cx, JSObject *pobj_, unsigned flags, AutoIdVector *props)
{
IdSet ht(cx);
if (!ht.init(32))
return false;
RootedObject pobj(cx, pobj_);
do {
Class *clasp = pobj->getClass();
if (pobj->isNative() &&
!pobj->getOps()->enumerate &&
!(clasp->flags & JSCLASS_NEW_ENUMERATE)) {
if (!clasp->enumerate(cx, pobj))
return false;
if (!EnumerateNativeProperties(cx, pobj, flags, ht, props))
return false;
} else {
if (pobj->is<ProxyObject>()) {
AutoIdVector proxyProps(cx);
if (flags & JSITER_OWNONLY) {
if (flags & JSITER_HIDDEN) {
if (!Proxy::getOwnPropertyNames(cx, pobj, proxyProps))
return false;
} else {
if (!Proxy::keys(cx, pobj, proxyProps))
return false;
}
} else {
if (!Proxy::enumerate(cx, pobj, proxyProps))
return false;
}
for (size_t n = 0, len = proxyProps.length(); n < len; n++) {
if (!Enumerate(cx, pobj, proxyProps[n], true, flags, ht, props))
return false;
}
/* Proxy objects enumerate the prototype on their own, so we are done here. */
break;
}
RootedValue state(cx);
RootedId id(cx);
JSIterateOp op = (flags & JSITER_HIDDEN) ? JSENUMERATE_INIT_ALL : JSENUMERATE_INIT;
if (!JSObject::enumerate(cx, pobj, op, &state, &id))
return false;
if (state.isMagic(JS_NATIVE_ENUMERATE)) {
if (!EnumerateNativeProperties(cx, pobj, flags, ht, props))
return false;
} else {
while (true) {
RootedId id(cx);
if (!JSObject::enumerate(cx, pobj, JSENUMERATE_NEXT, &state, &id))
return false;
if (state.isNull())
break;
if (!Enumerate(cx, pobj, id, true, flags, ht, props))
return false;
}
}
}
if (flags & JSITER_OWNONLY)
break;
} while ((pobj = pobj->getProto()) != NULL);
#ifdef JS_MORE_DETERMINISTIC
/*
* In some cases the enumeration order for an object depends on the
* execution mode (interpreter vs. JIT), especially for native objects
* with a class enumerate hook (where resolving a property changes the
* resulting enumeration order). These aren't really bugs, but the
* differences can change the generated output and confuse correctness
* fuzzers, so we sort the ids if such a fuzzer is running.
*
* We don't do this in the general case because (a) doing so is slow,
* and (b) it also breaks the web, which expects enumeration order to
* follow the order in which properties are added, in certain cases.
* Since ECMA does not specify an enumeration order for objects, both
* behaviors are technically correct to do.
*/
jsid *ids = props->begin();
size_t n = props->length();
AutoIdVector tmp(cx);
if (!tmp.resize(n))
return false;
PodCopy(tmp.begin(), ids, n);
if (!MergeSort(ids, n, tmp.begin(), SortComparatorIds(cx)))
return false;
#endif /* JS_MORE_DETERMINISTIC */
return true;
}
bool
js::VectorToIdArray(JSContext *cx, AutoIdVector &props, JSIdArray **idap)
{
JS_STATIC_ASSERT(sizeof(JSIdArray) > sizeof(jsid));
size_t len = props.length();
size_t idsz = len * sizeof(jsid);
size_t sz = (sizeof(JSIdArray) - sizeof(jsid)) + idsz;
JSIdArray *ida = static_cast<JSIdArray *>(cx->malloc_(sz));
if (!ida)
return false;
ida->length = static_cast<int>(len);
jsid *v = props.begin();
for (int i = 0; i < ida->length; i++)
ida->vector[i].init(v[i]);
*idap = ida;
return true;
}
JS_FRIEND_API(bool)
js::GetPropertyNames(JSContext *cx, JSObject *obj, unsigned flags, AutoIdVector *props)
{
return Snapshot(cx, obj, flags & (JSITER_OWNONLY | JSITER_HIDDEN), props);
}
size_t sCustomIteratorCount = 0;
static inline bool
GetCustomIterator(JSContext *cx, HandleObject obj, unsigned flags, MutableHandleValue vp)
{
JS_CHECK_RECURSION(cx, return false);
/* Check whether we have a valid __iterator__ method. */
HandlePropertyName name = cx->names().iteratorIntrinsic;
if (!JSObject::getProperty(cx, obj, obj, name, vp))
return false;
/* If there is no custom __iterator__ method, we are done here. */
if (!vp.isObject()) {
vp.setUndefined();
return true;
}
if (!cx->runningWithTrustedPrincipals())
++sCustomIteratorCount;
/* Otherwise call it and return that object. */
Value arg = BooleanValue((flags & JSITER_FOREACH) == 0);
if (!Invoke(cx, ObjectValue(*obj), vp, 1, &arg, vp))
return false;
if (vp.isPrimitive()) {
/*
* We are always coming from js::ValueToIterator, and we are no longer on
* trace, so the object we are iterating over is on top of the stack (-1).
*/
JSAutoByteString bytes;
if (!AtomToPrintableString(cx, name, &bytes))
return false;
RootedValue val(cx, ObjectValue(*obj));
js_ReportValueError2(cx, JSMSG_BAD_TRAP_RETURN_VALUE,
-1, val, NullPtr(), bytes.ptr());
return false;
}
return true;
}
template <typename T>
static inline bool
Compare(T *a, T *b, size_t c)
{
size_t n = (c + size_t(7)) / size_t(8);
switch (c % 8) {
case 0: do { if (*a++ != *b++) return false;
case 7: if (*a++ != *b++) return false;
case 6: if (*a++ != *b++) return false;
case 5: if (*a++ != *b++) return false;
case 4: if (*a++ != *b++) return false;
case 3: if (*a++ != *b++) return false;
case 2: if (*a++ != *b++) return false;
case 1: if (*a++ != *b++) return false;
} while (--n > 0);
}
return true;
}
static inline PropertyIteratorObject *
NewPropertyIteratorObject(JSContext *cx, unsigned flags)
{
if (flags & JSITER_ENUMERATE) {
RootedTypeObject type(cx, cx->getNewType(&PropertyIteratorObject::class_, NULL));
if (!type)
return NULL;
JSObject *metadata = NULL;
if (!NewObjectMetadata(cx, &metadata))
return NULL;
Class *clasp = &PropertyIteratorObject::class_;
RootedShape shape(cx, EmptyShape::getInitialShape(cx, clasp, NULL, NULL, metadata,
ITERATOR_FINALIZE_KIND));
if (!shape)
return NULL;
JSObject *obj = JSObject::create(cx, ITERATOR_FINALIZE_KIND,
GetInitialHeap(GenericObject, clasp), shape, type);
if (!obj)
return NULL;
JS_ASSERT(obj->numFixedSlots() == JSObject::ITER_CLASS_NFIXED_SLOTS);
return &obj->as<PropertyIteratorObject>();
}
return &NewBuiltinClassInstance(cx, &PropertyIteratorObject::class_)->as<PropertyIteratorObject>();
}
NativeIterator *
NativeIterator::allocateIterator(JSContext *cx, uint32_t slength, const AutoIdVector &props)
{
size_t plength = props.length();
NativeIterator *ni = (NativeIterator *)
cx->malloc_(sizeof(NativeIterator)
+ plength * sizeof(JSString *)
+ slength * sizeof(Shape *));
if (!ni)
return NULL;
AutoValueVector strings(cx);
ni->props_array = ni->props_cursor = (HeapPtr<JSFlatString> *) (ni + 1);
ni->props_end = ni->props_array + plength;
if (plength) {
for (size_t i = 0; i < plength; i++) {
JSFlatString *str = IdToString(cx, props[i]);
if (!str || !strings.append(StringValue(str)))
return NULL;
ni->props_array[i].init(str);
}
}
ni->next_ = NULL;
ni->prev_ = NULL;
return ni;
}
NativeIterator *
NativeIterator::allocateSentinel(JSContext *cx)
{
NativeIterator *ni = (NativeIterator *)js_malloc(sizeof(NativeIterator));
if (!ni)
return NULL;
PodZero(ni);
ni->next_ = ni;
ni->prev_ = ni;
return ni;
}
inline void
NativeIterator::init(JSObject *obj, JSObject *iterObj, unsigned flags, uint32_t slength, uint32_t key)
{
this->obj.init(obj);
this->iterObj_ = iterObj;
this->flags = flags;
this->shapes_array = (Shape **) this->props_end;
this->shapes_length = slength;
this->shapes_key = key;
}
static inline void
RegisterEnumerator(JSContext *cx, PropertyIteratorObject *iterobj, NativeIterator *ni)
{
/* Register non-escaping native enumerators (for-in) with the current context. */
if (ni->flags & JSITER_ENUMERATE) {
ni->link(cx->compartment()->enumerators);
JS_ASSERT(!(ni->flags & JSITER_ACTIVE));
ni->flags |= JSITER_ACTIVE;
}
}
static inline bool
VectorToKeyIterator(JSContext *cx, HandleObject obj, unsigned flags, AutoIdVector &keys,
uint32_t slength, uint32_t key, MutableHandleValue vp)
{
JS_ASSERT(!(flags & JSITER_FOREACH));
if (obj) {
if (obj->hasSingletonType() && !obj->setIteratedSingleton(cx))
return false;
types::MarkTypeObjectFlags(cx, obj, types::OBJECT_FLAG_ITERATED);
}
Rooted<PropertyIteratorObject *> iterobj(cx, NewPropertyIteratorObject(cx, flags));
if (!iterobj)
return false;
NativeIterator *ni = NativeIterator::allocateIterator(cx, slength, keys);
if (!ni)
return false;
ni->init(obj, iterobj, flags, slength, key);
if (slength) {
/*
* Fill in the shape array from scratch. We can't use the array that was
* computed for the cache lookup earlier, as constructing iterobj could
* have triggered a shape-regenerating GC. Don't bother with regenerating
* the shape key; if such a GC *does* occur, we can only get hits through
* the one-slot lastNativeIterator cache.
*/
JSObject *pobj = obj;
size_t ind = 0;
do {
ni->shapes_array[ind++] = pobj->lastProperty();
pobj = pobj->getProto();
} while (pobj);
JS_ASSERT(ind == slength);
}
iterobj->setNativeIterator(ni);
vp.setObject(*iterobj);
RegisterEnumerator(cx, iterobj, ni);
return true;
}
bool
js::VectorToKeyIterator(JSContext *cx, HandleObject obj, unsigned flags, AutoIdVector &props,
MutableHandleValue vp)
{
return VectorToKeyIterator(cx, obj, flags, props, 0, 0, vp);
}
bool
js::VectorToValueIterator(JSContext *cx, HandleObject obj, unsigned flags, AutoIdVector &keys,
MutableHandleValue vp)
{
JS_ASSERT(flags & JSITER_FOREACH);
if (obj) {
if (obj->hasSingletonType() && !obj->setIteratedSingleton(cx))
return false;
types::MarkTypeObjectFlags(cx, obj, types::OBJECT_FLAG_ITERATED);
}
Rooted<PropertyIteratorObject*> iterobj(cx, NewPropertyIteratorObject(cx, flags));
if (!iterobj)
return false;
NativeIterator *ni = NativeIterator::allocateIterator(cx, 0, keys);
if (!ni)
return false;
ni->init(obj, iterobj, flags, 0, 0);
iterobj->setNativeIterator(ni);
vp.setObject(*iterobj);
RegisterEnumerator(cx, iterobj, ni);
return true;
}
bool
js::EnumeratedIdVectorToIterator(JSContext *cx, HandleObject obj, unsigned flags,
AutoIdVector &props, MutableHandleValue vp)
{
if (!(flags & JSITER_FOREACH))
return VectorToKeyIterator(cx, obj, flags, props, vp);
return VectorToValueIterator(cx, obj, flags, props, vp);
}
static inline void
UpdateNativeIterator(NativeIterator *ni, JSObject *obj)
{
// Update the object for which the native iterator is associated, so
// SuppressDeletedPropertyHelper will recognize the iterator as a match.
ni->obj = obj;
}
bool
js::GetIterator(JSContext *cx, HandleObject obj, unsigned flags, MutableHandleValue vp)
{
if (flags == JSITER_FOR_OF) {
// for-of loop. The iterator is simply |obj.iterator()|.
RootedValue method(cx);
if (!JSObject::getProperty(cx, obj, obj, cx->names().iterator, &method))
return false;
// Throw if obj.iterator isn't callable. js::Invoke is about to check
// for this kind of error anyway, but it would throw an inscrutable
// error message about |method| rather than this nice one about |obj|.
if (!method.isObject() || !method.toObject().isCallable()) {
RootedValue val(cx, ObjectOrNullValue(obj));
char *bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, val, NullPtr());
if (!bytes)
return false;
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_NOT_ITERABLE, bytes);
js_free(bytes);
return false;
}
if (!Invoke(cx, ObjectOrNullValue(obj), method, 0, NULL, vp))
return false;
JSObject *resultObj = ToObject(cx, vp);
if (!resultObj)
return false;
vp.setObject(*resultObj);
return true;
}
Vector<Shape *, 8> shapes(cx);
uint32_t key = 0;
bool keysOnly = (flags == JSITER_ENUMERATE);
if (obj) {
if (JSIteratorOp op = obj->getClass()->ext.iteratorObject) {
JSObject *iterobj = op(cx, obj, !(flags & JSITER_FOREACH));
if (!iterobj)
return false;
vp.setObject(*iterobj);
types::MarkIteratorUnknown(cx);
return true;
}
if (keysOnly) {
/*
* Check to see if this is the same as the most recent object which
* was iterated over. We don't explicitly check for shapeless
* objects here, as they are not inserted into the cache and
* will result in a miss.
*/
PropertyIteratorObject *last = cx->runtime()->nativeIterCache.last;
if (last) {
NativeIterator *lastni = last->getNativeIterator();
if (!(lastni->flags & (JSITER_ACTIVE|JSITER_UNREUSABLE)) &&
obj->isNative() &&
obj->hasEmptyElements() &&
obj->lastProperty() == lastni->shapes_array[0])
{
JSObject *proto = obj->getProto();
if (proto->isNative() &&
proto->hasEmptyElements() &&
proto->lastProperty() == lastni->shapes_array[1] &&
!proto->getProto())
{
vp.setObject(*last);
UpdateNativeIterator(lastni, obj);
RegisterEnumerator(cx, last, lastni);
return true;
}
}
}
/*
* The iterator object for JSITER_ENUMERATE never escapes, so we
* don't care for the proper parent/proto to be set. This also
* allows us to re-use a previous iterator object that is not
* currently active.
*/
{
JSObject *pobj = obj;
do {
if (!pobj->isNative() ||
!pobj->hasEmptyElements() ||
pobj->hasUncacheableProto() ||
obj->getOps()->enumerate ||
pobj->getClass()->enumerate != JS_EnumerateStub) {
shapes.clear();
goto miss;
}
Shape *shape = pobj->lastProperty();
key = (key + (key << 16)) ^ (uintptr_t(shape) >> 3);
if (!shapes.append(shape))
return false;
pobj = pobj->getProto();
} while (pobj);
}
PropertyIteratorObject *iterobj = cx->runtime()->nativeIterCache.get(key);
if (iterobj) {
NativeIterator *ni = iterobj->getNativeIterator();
if (!(ni->flags & (JSITER_ACTIVE|JSITER_UNREUSABLE)) &&
ni->shapes_key == key &&
ni->shapes_length == shapes.length() &&
Compare(ni->shapes_array, shapes.begin(), ni->shapes_length)) {
vp.setObject(*iterobj);
UpdateNativeIterator(ni, obj);
RegisterEnumerator(cx, iterobj, ni);
if (shapes.length() == 2)
cx->runtime()->nativeIterCache.last = iterobj;
return true;
}
}
}
miss:
if (obj->is<ProxyObject>()) {
types::MarkIteratorUnknown(cx);
return Proxy::iterate(cx, obj, flags, vp);
}
if (!GetCustomIterator(cx, obj, flags, vp))
return false;
if (!vp.isUndefined()) {
types::MarkIteratorUnknown(cx);
return true;
}
}
/* NB: for (var p in null) succeeds by iterating over no properties. */
AutoIdVector keys(cx);
if (flags & JSITER_FOREACH) {
if (JS_LIKELY(obj != NULL) && !Snapshot(cx, obj, flags, &keys))
return false;
JS_ASSERT(shapes.empty());
if (!VectorToValueIterator(cx, obj, flags, keys, vp))
return false;
} else {
if (JS_LIKELY(obj != NULL) && !Snapshot(cx, obj, flags, &keys))
return false;
if (!VectorToKeyIterator(cx, obj, flags, keys, shapes.length(), key, vp))
return false;
}
PropertyIteratorObject *iterobj = &vp.toObject().as<PropertyIteratorObject>();
/* Cache the iterator object if possible. */
if (shapes.length())
cx->runtime()->nativeIterCache.set(key, iterobj);
if (shapes.length() == 2)
cx->runtime()->nativeIterCache.last = iterobj;
return true;
}
JSObject *
js::GetIteratorObject(JSContext *cx, HandleObject obj, uint32_t flags)
{
RootedValue value(cx);
if (!GetIterator(cx, obj, flags, &value))
return NULL;
return &value.toObject();
}
bool
js_ThrowStopIteration(JSContext *cx)
{
JS_ASSERT(!JS_IsExceptionPending(cx));
RootedValue v(cx);
if (js_FindClassObject(cx, JSProto_StopIteration, &v))
cx->setPendingException(v);
return false;
}
/*** Iterator objects ****************************************************************************/
bool
js::IteratorConstructor(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
if (args.length() == 0) {
js_ReportMissingArg(cx, args.calleev(), 0);
return false;
}
bool keyonly = false;
if (args.length() >= 2)
keyonly = ToBoolean(args[1]);
unsigned flags = JSITER_OWNONLY | (keyonly ? 0 : (JSITER_FOREACH | JSITER_KEYVALUE));
if (!ValueToIterator(cx, flags, args[0]))
return false;
args.rval().set(args[0]);
return true;
}
JS_ALWAYS_INLINE bool
IsIterator(HandleValue v)
{
return v.isObject() && v.toObject().hasClass(&PropertyIteratorObject::class_);
}
JS_ALWAYS_INLINE bool
iterator_next_impl(JSContext *cx, CallArgs args)
{
JS_ASSERT(IsIterator(args.thisv()));
RootedObject thisObj(cx, &args.thisv().toObject());
if (!js_IteratorMore(cx, thisObj, args.rval()))
return false;
if (!args.rval().toBoolean()) {
js_ThrowStopIteration(cx);
return false;
}
return js_IteratorNext(cx, thisObj, args.rval());
}
static bool
iterator_iterator(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
args.rval().set(args.thisv());
return true;
}
bool
iterator_next(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
return CallNonGenericMethod<IsIterator, iterator_next_impl>(cx, args);
}
static const JSFunctionSpec iterator_methods[] = {
JS_FN("iterator", iterator_iterator, 0, 0),
JS_FN("next", iterator_next, 0, 0),
JS_FS_END
};
static JSObject *
iterator_iteratorObject(JSContext *cx, HandleObject obj, bool keysonly)
{
return obj;
}
size_t
PropertyIteratorObject::sizeOfMisc(mozilla::MallocSizeOf mallocSizeOf) const
{
return mallocSizeOf(getPrivate());
}
void
PropertyIteratorObject::trace(JSTracer *trc, JSObject *obj)
{
if (NativeIterator *ni = obj->as<PropertyIteratorObject>().getNativeIterator())
ni->mark(trc);
}
void
PropertyIteratorObject::finalize(FreeOp *fop, JSObject *obj)
{
if (NativeIterator *ni = obj->as<PropertyIteratorObject>().getNativeIterator())
fop->free_(ni);
}
Class PropertyIteratorObject::class_ = {
"Iterator",
JSCLASS_IMPLEMENTS_BARRIERS |
JSCLASS_HAS_CACHED_PROTO(JSProto_Iterator) |
JSCLASS_HAS_PRIVATE |
JSCLASS_BACKGROUND_FINALIZE,
JS_PropertyStub, /* addProperty */
JS_DeletePropertyStub, /* delProperty */
JS_PropertyStub, /* getProperty */
JS_StrictPropertyStub, /* setProperty */
JS_EnumerateStub,
JS_ResolveStub,
JS_ConvertStub,
finalize,
NULL, /* checkAccess */
NULL, /* call */
NULL, /* hasInstance */
NULL, /* construct */
trace,
{
NULL, /* outerObject */
NULL, /* innerObject */
iterator_iteratorObject,
}
};
const uint32_t CLOSED_INDEX = UINT32_MAX;
JSObject *
ElementIteratorObject::create(JSContext *cx, Handle<Value> target)
{
RootedObject proto(cx, cx->global()->getOrCreateElementIteratorPrototype(cx));
if (!proto)
return NULL;
RootedObject iterobj(cx, NewObjectWithGivenProto(cx, &class_, proto, cx->global()));
if (iterobj) {
iterobj->setReservedSlot(TargetSlot, target);
iterobj->setReservedSlot(IndexSlot, Int32Value(0));
}
return iterobj;
}
static bool
IsElementIterator(HandleValue v)
{
return v.isObject() && v.toObject().is<ElementIteratorObject>();
}
bool
ElementIteratorObject::next(JSContext *cx, unsigned argc, Value *vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
return CallNonGenericMethod(cx, IsElementIterator, next_impl, args);
}
bool
ElementIteratorObject::next_impl(JSContext *cx, CallArgs args)
{
RootedObject iterobj(cx, &args.thisv().toObject());
uint32_t i, length;
RootedValue target(cx, iterobj->getReservedSlot(TargetSlot));
RootedObject obj(cx);
// Get target.length.
if (target.isString()) {
length = uint32_t(target.toString()->length());
} else {
obj = ToObjectFromStack(cx, target);
if (!obj)
goto close;
if (!GetLengthProperty(cx, obj, &length))
goto close;
}
// Check target.length.
i = uint32_t(iterobj->getReservedSlot(IndexSlot).toInt32());
if (i >= length) {
js_ThrowStopIteration(cx);
goto close;
}
// Get target[i].
JS_ASSERT(i + 1 > i);
if (target.isString()) {
JSString *c = cx->runtime()->staticStrings.getUnitStringForElement(cx, target.toString(), i);
if (!c)
goto close;
args.rval().setString(c);
} else {
if (!JSObject::getElement(cx, obj, obj, i, args.rval()))
goto close;
}
// On success, bump the index.
iterobj->setReservedSlot(IndexSlot, Int32Value(int32_t(i + 1)));
return true;
close:
// Close the iterator. The TargetSlot will never be used again, so don't keep a
// reference to it.
iterobj->setReservedSlot(TargetSlot, UndefinedValue());
iterobj->setReservedSlot(IndexSlot, Int32Value(int32_t(CLOSED_INDEX)));
return false;
}
Class ElementIteratorObject::class_ = {
"Array Iterator",
JSCLASS_IMPLEMENTS_BARRIERS |
JSCLASS_HAS_RESERVED_SLOTS(ElementIteratorObject::NumSlots),
JS_PropertyStub, /* addProperty */
JS_DeletePropertyStub, /* delProperty */
JS_PropertyStub, /* getProperty */
JS_StrictPropertyStub, /* setProperty */
JS_EnumerateStub,
JS_ResolveStub,
JS_ConvertStub,
NULL /* finalize */
};
const JSFunctionSpec ElementIteratorObject::methods[] = {
JS_FN("next", next, 0, 0),
JS_FS_END
};
static bool
CloseLegacyGenerator(JSContext *cx, HandleObject genobj);
bool
js::ValueToIterator(JSContext *cx, unsigned flags, MutableHandleValue vp)
{
/* JSITER_KEYVALUE must always come with JSITER_FOREACH */
JS_ASSERT_IF(flags & JSITER_KEYVALUE, flags & JSITER_FOREACH);
/*
* Make sure the more/next state machine doesn't get stuck. A value might be
* left in iterValue when a trace is left due to an operation time-out after
* JSOP_MOREITER but before the value is picked up by FOR*.
*/
cx->iterValue.setMagic(JS_NO_ITER_VALUE);
RootedObject obj(cx);
if (vp.isObject()) {
/* Common case. */
obj = &vp.toObject();
} else {
/*
* Enumerating over null and undefined gives an empty enumerator.
* This is contrary to ECMA-262 9.9 ToObject, invoked from step 3 of
* the first production in 12.6.4 and step 4 of the second production,
* but it's "web JS" compatible. ES5 fixed for-in to match this de-facto
* standard.
*/
if (flags & JSITER_ENUMERATE) {
if (!js_ValueToObjectOrNull(cx, vp, &obj))
return false;
/* fall through */
} else {
obj = js_ValueToNonNullObject(cx, vp);
if (!obj)
return false;
}
}
return GetIterator(cx, obj, flags, vp);
}