Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
4540 lines (3880 sloc) 132 KB
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "builtin/Array-inl.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/Maybe.h"
#include "mozilla/TextUtils.h"
#include <algorithm>
#include "jsapi.h"
#include "jsfriendapi.h"
#include "jsnum.h"
#include "jstypes.h"
#include "jsutil.h"
#include "ds/Sort.h"
#include "gc/Heap.h"
#include "jit/InlinableNatives.h"
#include "js/Class.h"
#include "js/Conversions.h"
#include "js/PropertySpec.h"
#include "util/StringBuffer.h"
#include "util/Text.h"
#include "vm/ArgumentsObject.h"
#include "vm/Interpreter.h"
#include "vm/Iteration.h"
#include "vm/JSAtom.h"
#include "vm/JSContext.h"
#include "vm/JSFunction.h"
#include "vm/JSObject.h"
#include "vm/SelfHosting.h"
#include "vm/Shape.h"
#include "vm/TypedArrayObject.h"
#include "vm/WrapperObject.h"
#include "vm/ArgumentsObject-inl.h"
#include "vm/ArrayObject-inl.h"
#include "vm/Caches-inl.h"
#include "vm/GeckoProfiler-inl.h"
#include "vm/Interpreter-inl.h"
#include "vm/JSAtom-inl.h"
#include "vm/NativeObject-inl.h"
using namespace js;
using mozilla::Abs;
using mozilla::ArrayLength;
using mozilla::CeilingLog2;
using mozilla::CheckedInt;
using mozilla::DebugOnly;
using mozilla::IsAsciiDigit;
using mozilla::Maybe;
using JS::AutoCheckCannotGC;
using JS::IsArrayAnswer;
using JS::ToUint32;
bool JS::IsArray(JSContext* cx, HandleObject obj, IsArrayAnswer* answer) {
if (obj->is<ArrayObject>()) {
*answer = IsArrayAnswer::Array;
return true;
}
if (obj->is<ProxyObject>()) {
return Proxy::isArray(cx, obj, answer);
}
*answer = IsArrayAnswer::NotArray;
return true;
}
bool JS::IsArray(JSContext* cx, HandleObject obj, bool* isArray) {
IsArrayAnswer answer;
if (!IsArray(cx, obj, &answer)) {
return false;
}
if (answer == IsArrayAnswer::RevokedProxy) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_PROXY_REVOKED);
return false;
}
*isArray = answer == IsArrayAnswer::Array;
return true;
}
bool js::IsArrayFromJit(JSContext* cx, HandleObject obj, bool* isArray) {
return JS::IsArray(cx, obj, isArray);
}
// ES2017 7.1.15 ToLength, but clamped to the [0,2^32-2] range.
static bool ToLengthClamped(JSContext* cx, HandleValue v, uint32_t* out) {
if (v.isInt32()) {
int32_t i = v.toInt32();
*out = i < 0 ? 0 : i;
return true;
}
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumber(cx, v, &d)) {
return false;
}
}
d = JS::ToInteger(d);
if (d <= 0.0) {
*out = 0;
} else if (d < double(UINT32_MAX - 1)) {
*out = uint32_t(d);
} else {
*out = UINT32_MAX;
}
return true;
}
bool js::GetLengthProperty(JSContext* cx, HandleObject obj, uint32_t* lengthp) {
if (obj->is<ArrayObject>()) {
*lengthp = obj->as<ArrayObject>().length();
return true;
}
if (obj->is<ArgumentsObject>()) {
ArgumentsObject& argsobj = obj->as<ArgumentsObject>();
if (!argsobj.hasOverriddenLength()) {
*lengthp = argsobj.initialLength();
return true;
}
}
RootedValue value(cx);
if (!GetProperty(cx, obj, obj, cx->names().length, &value)) {
return false;
}
if (!ToLengthClamped(cx, value, lengthp)) {
return false;
}
return true;
}
// ES2017 7.1.15 ToLength.
static bool ToLength(JSContext* cx, HandleValue v, uint64_t* out) {
if (v.isInt32()) {
int32_t i = v.toInt32();
*out = i < 0 ? 0 : i;
return true;
}
double d;
if (v.isDouble()) {
d = v.toDouble();
} else {
if (!ToNumber(cx, v, &d)) {
return false;
}
}
d = JS::ToInteger(d);
if (d <= 0.0) {
*out = 0;
} else {
*out = uint64_t(Min(d, DOUBLE_INTEGRAL_PRECISION_LIMIT - 1));
}
return true;
}
static MOZ_ALWAYS_INLINE bool GetLengthProperty(JSContext* cx, HandleObject obj,
uint64_t* lengthp) {
if (obj->is<ArrayObject>()) {
*lengthp = obj->as<ArrayObject>().length();
return true;
}
if (obj->is<ArgumentsObject>()) {
ArgumentsObject& argsobj = obj->as<ArgumentsObject>();
if (!argsobj.hasOverriddenLength()) {
*lengthp = argsobj.initialLength();
return true;
}
}
RootedValue value(cx);
if (!GetProperty(cx, obj, obj, cx->names().length, &value)) {
return false;
}
return ToLength(cx, value, lengthp);
}
/*
* Determine if the id represents an array index.
*
* An id is an array index according to ECMA by (15.4):
*
* "Array objects give special treatment to a certain class of property names.
* A property name P (in the form of a string value) is an array index if and
* only if ToString(ToUint32(P)) is equal to P and ToUint32(P) is not equal
* to 2^32-1."
*
* This means the largest allowed index is actually 2^32-2 (4294967294).
*
* In our implementation, it would be sufficient to check for id.isInt32()
* except that by using signed 31-bit integers we miss the top half of the
* valid range. This function checks the string representation itself; note
* that calling a standard conversion routine might allow strings such as
* "08" or "4.0" as array indices, which they are not.
*
*/
template <typename CharT>
static bool StringIsArrayIndexHelper(const CharT* s, uint32_t length,
uint32_t* indexp) {
const CharT* end = s + length;
if (length == 0 || length > (sizeof("4294967294") - 1) || !IsAsciiDigit(*s)) {
return false;
}
uint32_t c = 0, previous = 0;
uint32_t index = AsciiDigitToNumber(*s++);
/* Don't allow leading zeros. */
if (index == 0 && s != end) {
return false;
}
for (; s < end; s++) {
if (!IsAsciiDigit(*s)) {
return false;
}
previous = index;
c = AsciiDigitToNumber(*s);
index = 10 * index + c;
}
/* Make sure we didn't overflow. */
if (previous < (MAX_ARRAY_INDEX / 10) ||
(previous == (MAX_ARRAY_INDEX / 10) && c <= (MAX_ARRAY_INDEX % 10))) {
MOZ_ASSERT(index <= MAX_ARRAY_INDEX);
*indexp = index;
return true;
}
return false;
}
JS_FRIEND_API bool js::StringIsArrayIndex(JSLinearString* str,
uint32_t* indexp) {
AutoCheckCannotGC nogc;
return str->hasLatin1Chars()
? StringIsArrayIndexHelper(str->latin1Chars(nogc), str->length(),
indexp)
: StringIsArrayIndexHelper(str->twoByteChars(nogc), str->length(),
indexp);
}
JS_FRIEND_API bool js::StringIsArrayIndex(const char16_t* str, uint32_t length,
uint32_t* indexp) {
return StringIsArrayIndexHelper(str, length, indexp);
}
JS_FRIEND_API bool js::StringIsArrayIndex(const char* str, uint32_t length,
uint32_t* indexp) {
return StringIsArrayIndexHelper(str, length, indexp);
}
template <typename T>
static bool ToId(JSContext* cx, T index, MutableHandleId id);
template <>
bool ToId(JSContext* cx, uint32_t index, MutableHandleId id) {
return IndexToId(cx, index, id);
}
template <>
bool ToId(JSContext* cx, uint64_t index, MutableHandleId id) {
MOZ_ASSERT(index < uint64_t(DOUBLE_INTEGRAL_PRECISION_LIMIT));
if (index == uint32_t(index)) {
return IndexToId(cx, uint32_t(index), id);
}
Value tmp = DoubleValue(index);
return ValueToId<CanGC>(cx, HandleValue::fromMarkedLocation(&tmp), id);
}
/*
* If the property at the given index exists, get its value into |vp| and set
* |*hole| to false. Otherwise set |*hole| to true and |vp| to Undefined.
*/
template <typename T>
static bool HasAndGetElement(JSContext* cx, HandleObject obj,
HandleObject receiver, T index, bool* hole,
MutableHandleValue vp) {
if (obj->isNative()) {
NativeObject* nobj = &obj->as<NativeObject>();
if (index < nobj->getDenseInitializedLength()) {
vp.set(nobj->getDenseElement(size_t(index)));
if (!vp.isMagic(JS_ELEMENTS_HOLE)) {
*hole = false;
return true;
}
}
if (nobj->is<ArgumentsObject>() && index <= UINT32_MAX) {
if (nobj->as<ArgumentsObject>().maybeGetElement(uint32_t(index), vp)) {
*hole = false;
return true;
}
}
}
RootedId id(cx);
if (!ToId(cx, index, &id)) {
return false;
}
bool found;
if (!HasProperty(cx, obj, id, &found)) {
return false;
}
if (found) {
if (!GetProperty(cx, obj, receiver, id, vp)) {
return false;
}
} else {
vp.setUndefined();
}
*hole = !found;
return true;
}
template <typename T>
static inline bool HasAndGetElement(JSContext* cx, HandleObject obj, T index,
bool* hole, MutableHandleValue vp) {
return HasAndGetElement(cx, obj, obj, index, hole, vp);
}
bool ElementAdder::append(JSContext* cx, HandleValue v) {
MOZ_ASSERT(index_ < length_);
if (resObj_) {
NativeObject* resObj = &resObj_->as<NativeObject>();
DenseElementResult result =
resObj->setOrExtendDenseElements(cx, index_, v.address(), 1);
if (result == DenseElementResult::Failure) {
return false;
}
if (result == DenseElementResult::Incomplete) {
if (!DefineDataElement(cx, resObj_, index_, v)) {
return false;
}
}
} else {
vp_[index_] = v;
}
index_++;
return true;
}
void ElementAdder::appendHole() {
MOZ_ASSERT(getBehavior_ == ElementAdder::CheckHasElemPreserveHoles);
MOZ_ASSERT(index_ < length_);
if (!resObj_) {
vp_[index_].setMagic(JS_ELEMENTS_HOLE);
}
index_++;
}
bool js::GetElementsWithAdder(JSContext* cx, HandleObject obj,
HandleObject receiver, uint32_t begin,
uint32_t end, ElementAdder* adder) {
MOZ_ASSERT(begin <= end);
RootedValue val(cx);
for (uint32_t i = begin; i < end; i++) {
if (adder->getBehavior() == ElementAdder::CheckHasElemPreserveHoles) {
bool hole;
if (!HasAndGetElement(cx, obj, receiver, i, &hole, &val)) {
return false;
}
if (hole) {
adder->appendHole();
continue;
}
} else {
MOZ_ASSERT(adder->getBehavior() == ElementAdder::GetElement);
if (!GetElement(cx, obj, receiver, i, &val)) {
return false;
}
}
if (!adder->append(cx, val)) {
return false;
}
}
return true;
}
static inline bool IsPackedArrayOrNoExtraIndexedProperties(JSObject* obj,
uint64_t length) {
return (IsPackedArray(obj) && obj->as<ArrayObject>().length() == length) ||
!ObjectMayHaveExtraIndexedProperties(obj);
}
static bool GetDenseElements(NativeObject* aobj, uint32_t length, Value* vp) {
MOZ_ASSERT(IsPackedArrayOrNoExtraIndexedProperties(aobj, length));
if (length > aobj->getDenseInitializedLength()) {
return false;
}
for (size_t i = 0; i < length; i++) {
vp[i] = aobj->getDenseElement(i);
// No other indexed properties so hole => undefined.
if (vp[i].isMagic(JS_ELEMENTS_HOLE)) {
vp[i] = UndefinedValue();
}
}
return true;
}
bool js::GetElements(JSContext* cx, HandleObject aobj, uint32_t length,
Value* vp) {
if (IsPackedArrayOrNoExtraIndexedProperties(aobj, length)) {
if (GetDenseElements(&aobj->as<NativeObject>(), length, vp)) {
return true;
}
}
if (aobj->is<ArgumentsObject>()) {
ArgumentsObject& argsobj = aobj->as<ArgumentsObject>();
if (!argsobj.hasOverriddenLength()) {
if (argsobj.maybeGetElements(0, length, vp)) {
return true;
}
}
}
if (aobj->is<TypedArrayObject>()) {
Handle<TypedArrayObject*> typedArray = aobj.as<TypedArrayObject>();
if (typedArray->length() == length) {
return TypedArrayObject::getElements(cx, typedArray, vp);
}
}
if (js::GetElementsOp op = aobj->getOpsGetElements()) {
ElementAdder adder(cx, vp, length, ElementAdder::GetElement);
return op(cx, aobj, 0, length, &adder);
}
for (uint32_t i = 0; i < length; i++) {
if (!GetElement(cx, aobj, aobj, i,
MutableHandleValue::fromMarkedLocation(&vp[i]))) {
return false;
}
}
return true;
}
static inline bool GetArrayElement(JSContext* cx, HandleObject obj,
uint64_t index, MutableHandleValue vp) {
if (obj->isNative()) {
NativeObject* nobj = &obj->as<NativeObject>();
if (index < nobj->getDenseInitializedLength()) {
vp.set(nobj->getDenseElement(size_t(index)));
if (!vp.isMagic(JS_ELEMENTS_HOLE)) {
return true;
}
}
if (nobj->is<ArgumentsObject>() && index <= UINT32_MAX) {
if (nobj->as<ArgumentsObject>().maybeGetElement(uint32_t(index), vp)) {
return true;
}
}
}
RootedId id(cx);
if (!ToId(cx, index, &id)) {
return false;
}
return GetProperty(cx, obj, obj, id, vp);
}
static inline bool DefineArrayElement(JSContext* cx, HandleObject obj,
uint64_t index, HandleValue value) {
RootedId id(cx);
if (!ToId(cx, index, &id)) {
return false;
}
return DefineDataProperty(cx, obj, id, value);
}
// Set the value of the property at the given index to v.
static inline bool SetArrayElement(JSContext* cx, HandleObject obj,
uint64_t index, HandleValue v) {
RootedId id(cx);
if (!ToId(cx, index, &id)) {
return false;
}
return SetProperty(cx, obj, id, v);
}
/*
* Attempt to delete the element |index| from |obj| as if by
* |obj.[[Delete]](index)|.
*
* If an error occurs while attempting to delete the element (that is, the call
* to [[Delete]] threw), return false.
*
* Otherwise call result.succeed() or result.fail() to indicate whether the
* deletion attempt succeeded (that is, whether the call to [[Delete]] returned
* true or false). (Deletes generally fail only when the property is
* non-configurable, but proxies may implement different semantics.)
*/
static bool DeleteArrayElement(JSContext* cx, HandleObject obj, uint64_t index,
ObjectOpResult& result) {
if (obj->is<ArrayObject>() && !obj->as<NativeObject>().isIndexed() &&
!obj->as<NativeObject>().denseElementsAreSealed()) {
ArrayObject* aobj = &obj->as<ArrayObject>();
if (index <= UINT32_MAX) {
uint32_t idx = uint32_t(index);
if (idx < aobj->getDenseInitializedLength()) {
if (!aobj->maybeCopyElementsForWrite(cx)) {
return false;
}
if (idx + 1 == aobj->getDenseInitializedLength()) {
aobj->setDenseInitializedLengthMaybeNonExtensible(cx, idx);
} else {
aobj->markDenseElementsNotPacked(cx);
aobj->setDenseElement(idx, MagicValue(JS_ELEMENTS_HOLE));
}
if (!SuppressDeletedElement(cx, obj, idx)) {
return false;
}
}
}
return result.succeed();
}
RootedId id(cx);
if (!ToId(cx, index, &id)) {
return false;
}
return DeleteProperty(cx, obj, id, result);
}
/* ES6 draft rev 32 (2 Febr 2015) 7.3.7 */
static bool DeletePropertyOrThrow(JSContext* cx, HandleObject obj,
uint64_t index) {
ObjectOpResult success;
if (!DeleteArrayElement(cx, obj, index, success)) {
return false;
}
if (!success) {
RootedId id(cx);
if (!ToId(cx, index, &id)) {
return false;
}
return success.reportError(cx, obj, id);
}
return true;
}
static bool DeletePropertiesOrThrow(JSContext* cx, HandleObject obj,
uint64_t len, uint64_t finalLength) {
if (obj->is<ArrayObject>() && !obj->as<NativeObject>().isIndexed() &&
!obj->as<NativeObject>().denseElementsAreSealed()) {
if (len <= UINT32_MAX) {
// Skip forward to the initialized elements of this array.
len = Min(uint32_t(len),
obj->as<ArrayObject>().getDenseInitializedLength());
}
}
for (uint64_t k = len; k > finalLength; k--) {
if (!CheckForInterrupt(cx)) {
return false;
}
if (!DeletePropertyOrThrow(cx, obj, k - 1)) {
return false;
}
}
return true;
}
static bool SetArrayLengthProperty(JSContext* cx, HandleArrayObject obj,
HandleValue value) {
RootedId id(cx, NameToId(cx->names().length));
ObjectOpResult result;
if (obj->lengthIsWritable()) {
if (!ArraySetLength(cx, obj, id, JSPROP_PERMANENT, value, result)) {
return false;
}
} else {
MOZ_ALWAYS_TRUE(result.fail(JSMSG_READ_ONLY));
}
return result.checkStrict(cx, obj, id);
}
static bool SetLengthProperty(JSContext* cx, HandleObject obj,
uint64_t length) {
MOZ_ASSERT(length < uint64_t(DOUBLE_INTEGRAL_PRECISION_LIMIT));
RootedValue v(cx, NumberValue(length));
if (obj->is<ArrayObject>()) {
return SetArrayLengthProperty(cx, obj.as<ArrayObject>(), v);
}
return SetProperty(cx, obj, cx->names().length, v);
}
bool js::SetLengthProperty(JSContext* cx, HandleObject obj, uint32_t length) {
RootedValue v(cx, NumberValue(length));
if (obj->is<ArrayObject>()) {
return SetArrayLengthProperty(cx, obj.as<ArrayObject>(), v);
}
return SetProperty(cx, obj, cx->names().length, v);
}
static bool array_length_getter(JSContext* cx, HandleObject obj, HandleId id,
MutableHandleValue vp) {
vp.setNumber(obj->as<ArrayObject>().length());
return true;
}
static bool array_length_setter(JSContext* cx, HandleObject obj, HandleId id,
HandleValue v, ObjectOpResult& result) {
MOZ_ASSERT(id == NameToId(cx->names().length));
if (!obj->is<ArrayObject>()) {
// This array .length property was found on the prototype
// chain. Ideally the setter should not have been called, but since
// we're here, do an impression of SetPropertyByDefining.
return DefineDataProperty(cx, obj, id, v, JSPROP_ENUMERATE, result);
}
HandleArrayObject arr = obj.as<ArrayObject>();
MOZ_ASSERT(arr->lengthIsWritable(),
"setter shouldn't be called if property is non-writable");
return ArraySetLength(cx, arr, id, JSPROP_PERMANENT, v, result);
}
struct ReverseIndexComparator {
bool operator()(const uint32_t& a, const uint32_t& b, bool* lessOrEqualp) {
MOZ_ASSERT(a != b, "how'd we get duplicate indexes?");
*lessOrEqualp = b <= a;
return true;
}
};
static bool MaybeInIteration(HandleObject obj, JSContext* cx) {
/*
* Don't optimize if the array might be in the midst of iteration. We
* rely on this to be able to safely move dense array elements around with
* just a memmove (see NativeObject::moveDenseArrayElements), without worrying
* about updating any in-progress enumerators for properties implicitly
* deleted if a hole is moved from one location to another location not yet
* visited. See bug 690622.
*
* Note that it's fine to optimize if |obj| is on the prototype of another
* object: SuppressDeletedProperty only suppresses properties deleted from
* the iterated object itself.
*/
if (MOZ_LIKELY(!ObjectRealm::get(obj).objectMaybeInIteration(obj))) {
return false;
}
ObjectGroup* group = JSObject::getGroup(cx, obj);
if (MOZ_UNLIKELY(!group)) {
cx->recoverFromOutOfMemory();
return true;
}
AutoSweepObjectGroup sweep(group);
if (MOZ_UNLIKELY(group->hasAllFlags(sweep, OBJECT_FLAG_ITERATED))) {
return true;
}
return false;
}
/* ES6 draft rev 34 (2015 Feb 20) 9.4.2.4 ArraySetLength */
bool js::ArraySetLength(JSContext* cx, Handle<ArrayObject*> arr, HandleId id,
unsigned attrs, HandleValue value,
ObjectOpResult& result) {
MOZ_ASSERT(id == NameToId(cx->names().length));
if (!arr->maybeCopyElementsForWrite(cx)) {
return false;
}
// Step 1.
uint32_t newLen;
if (attrs & JSPROP_IGNORE_VALUE) {
MOZ_ASSERT(value.isUndefined());
// The spec has us calling OrdinaryDefineOwnProperty if
// Desc.[[Value]] is absent, but our implementation is so different that
// this is impossible. Instead, set newLen to the current length and
// proceed to step 9.
newLen = arr->length();
} else {
// Step 2 is irrelevant in our implementation.
// Step 3.
if (!ToUint32(cx, value, &newLen)) {
return false;
}
// Step 4.
double d;
if (!ToNumber(cx, value, &d)) {
return false;
}
// Step 5.
if (d != newLen) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_BAD_ARRAY_LENGTH);
return false;
}
// Steps 6-8 are irrelevant in our implementation.
}
// Steps 9-11.
bool lengthIsWritable = arr->lengthIsWritable();
#ifdef DEBUG
{
RootedShape lengthShape(cx, arr->lookupPure(id));
MOZ_ASSERT(lengthShape);
MOZ_ASSERT(lengthShape->writable() == lengthIsWritable);
}
#endif
uint32_t oldLen = arr->length();
// Part of steps 1.a, 12.a, and 16: Fail if we're being asked to change
// enumerability or configurability, or otherwise break the object
// invariants. (ES6 checks these by calling OrdinaryDefineOwnProperty, but
// in SM, the array length property is hardly ordinary.)
if ((attrs & (JSPROP_PERMANENT | JSPROP_IGNORE_PERMANENT)) == 0 ||
(attrs & (JSPROP_ENUMERATE | JSPROP_IGNORE_ENUMERATE)) ==
JSPROP_ENUMERATE ||
(attrs & (JSPROP_GETTER | JSPROP_SETTER)) != 0 ||
(!lengthIsWritable &&
(attrs & (JSPROP_READONLY | JSPROP_IGNORE_READONLY)) == 0)) {
return result.fail(JSMSG_CANT_REDEFINE_PROP);
}
// Steps 12-13 for arrays with non-writable length.
if (!lengthIsWritable) {
if (newLen == oldLen) {
return result.succeed();
}
return result.fail(JSMSG_CANT_REDEFINE_ARRAY_LENGTH);
}
// Step 19.
bool succeeded = true;
do {
// The initialized length and capacity of an array only need updating
// when non-hole elements are added or removed, which doesn't happen
// when array length stays the same or increases.
if (newLen >= oldLen) {
break;
}
// Attempt to propagate dense-element optimization tricks, if possible,
// and avoid the generic (and accordingly slow) deletion code below.
// We can only do this if there are only densely-indexed elements.
// Once there's a sparse indexed element, there's no good way to know,
// save by enumerating all the properties to find it. But we *have* to
// know in case that sparse indexed element is non-configurable, as
// that element must prevent any deletions below it. Bug 586842 should
// fix this inefficiency by moving indexed storage to be entirely
// separate from non-indexed storage.
// A second reason for this optimization to be invalid is an active
// for..in iteration over the array. Keys deleted before being reached
// during the iteration must not be visited, and suppressing them here
// would be too costly.
// This optimization is also invalid when there are sealed
// (non-configurable) elements.
if (!arr->isIndexed() && !MaybeInIteration(arr, cx) &&
!arr->denseElementsAreSealed()) {
if (!arr->maybeCopyElementsForWrite(cx)) {
return false;
}
uint32_t oldCapacity = arr->getDenseCapacity();
uint32_t oldInitializedLength = arr->getDenseInitializedLength();
MOZ_ASSERT(oldCapacity >= oldInitializedLength);
if (oldInitializedLength > newLen) {
arr->setDenseInitializedLengthMaybeNonExtensible(cx, newLen);
}
if (oldCapacity > newLen) {
if (arr->isExtensible()) {
arr->shrinkElements(cx, newLen);
} else {
MOZ_ASSERT(arr->getDenseInitializedLength() ==
arr->getDenseCapacity());
}
}
// We've done the work of deleting any dense elements needing
// deletion, and there are no sparse elements. Thus we can skip
// straight to defining the length.
break;
}
// Step 15.
//
// Attempt to delete all elements above the new length, from greatest
// to least. If any of these deletions fails, we're supposed to define
// the length to one greater than the index that couldn't be deleted,
// *with the property attributes specified*. This might convert the
// length to be not the value specified, yet non-writable. (You may be
// forgiven for thinking these are interesting semantics.) Example:
//
// var arr =
// Object.defineProperty([0, 1, 2, 3], 1, { writable: false });
// Object.defineProperty(arr, "length",
// { value: 0, writable: false });
//
// will convert |arr| to an array of non-writable length two, then
// throw a TypeError.
//
// We implement this behavior, in the relevant lops below, by setting
// |succeeded| to false. Then we exit the loop, define the length
// appropriately, and only then throw a TypeError, if necessary.
uint32_t gap = oldLen - newLen;
const uint32_t RemoveElementsFastLimit = 1 << 24;
if (gap < RemoveElementsFastLimit) {
// If we're removing a relatively small number of elements, just do
// it exactly by the spec.
while (newLen < oldLen) {
// Step 15a.
oldLen--;
// Steps 15b-d.
ObjectOpResult deleteSucceeded;
if (!DeleteElement(cx, arr, oldLen, deleteSucceeded)) {
return false;
}
if (!deleteSucceeded) {
newLen = oldLen + 1;
succeeded = false;
break;
}
}
} else {
// If we're removing a large number of elements from an array
// that's probably sparse, try a different tack. Get all the own
// property names, sift out the indexes in the deletion range into
// a vector, sort the vector greatest to least, then delete the
// indexes greatest to least using that vector. See bug 322135.
//
// This heuristic's kind of a huge guess -- "large number of
// elements" and "probably sparse" are completely unprincipled
// predictions. In the long run, bug 586842 will support the right
// fix: store sparse elements in a sorted data structure that
// permits fast in-reverse-order traversal and concurrent removals.
Vector<uint32_t> indexes(cx);
{
RootedIdVector props(cx);
if (!GetPropertyKeys(cx, arr, JSITER_OWNONLY | JSITER_HIDDEN, &props)) {
return false;
}
for (size_t i = 0; i < props.length(); i++) {
if (!CheckForInterrupt(cx)) {
return false;
}
uint32_t index;
if (!IdIsIndex(props[i], &index)) {
continue;
}
if (index >= newLen && index < oldLen) {
if (!indexes.append(index)) {
return false;
}
}
}
}
uint32_t count = indexes.length();
{
// We should use radix sort to be O(n), but this is uncommon
// enough that we'll punt til someone complains.
Vector<uint32_t> scratch(cx);
if (!scratch.resize(count)) {
return false;
}
MOZ_ALWAYS_TRUE(MergeSort(indexes.begin(), count, scratch.begin(),
ReverseIndexComparator()));
}
uint32_t index = UINT32_MAX;
for (uint32_t i = 0; i < count; i++) {
MOZ_ASSERT(indexes[i] < index, "indexes should never repeat");
index = indexes[i];
// Steps 15b-d.
ObjectOpResult deleteSucceeded;
if (!DeleteElement(cx, arr, index, deleteSucceeded)) {
return false;
}
if (!deleteSucceeded) {
newLen = index + 1;
succeeded = false;
break;
}
}
}
} while (false);
// Update array length. Technically we should have been doing this
// throughout the loop, in step 19.d.iii.
arr->setLength(cx, newLen);
// Step 20.
if (attrs & JSPROP_READONLY) {
// Yes, we totally drop a non-stub getter/setter from a defineProperty
// API call on the floor here. Given that getter/setter will go away in
// the long run, with accessors replacing them both internally and at the
// API level, just run with this.
RootedShape lengthShape(cx, arr->lookup(cx, id));
if (!NativeObject::changeProperty(
cx, arr, lengthShape, lengthShape->attributes() | JSPROP_READONLY,
array_length_getter, array_length_setter)) {
return false;
}
}
// All operations past here until the |!succeeded| code must be infallible,
// so that all element fields remain properly synchronized.
// Trim the initialized length, if needed, to preserve the <= length
// invariant. (Capacity was already reduced during element deletion, if
// necessary.)
ObjectElements* header = arr->getElementsHeader();
header->initializedLength = Min(header->initializedLength, newLen);
if (!arr->isExtensible()) {
arr->shrinkCapacityToInitializedLength(cx);
}
if (attrs & JSPROP_READONLY) {
arr->setNonWritableLength(cx);
}
if (!succeeded) {
return result.fail(JSMSG_CANT_TRUNCATE_ARRAY);
}
return result.succeed();
}
static bool array_addProperty(JSContext* cx, HandleObject obj, HandleId id,
HandleValue v) {
ArrayObject* arr = &obj->as<ArrayObject>();
uint32_t index;
if (!IdIsIndex(id, &index)) {
return true;
}
uint32_t length = arr->length();
if (index >= length) {
MOZ_ASSERT(arr->lengthIsWritable(),
"how'd this element get added if length is non-writable?");
arr->setLength(cx, index + 1);
}
return true;
}
static inline bool ObjectMayHaveExtraIndexedOwnProperties(JSObject* obj) {
if (!obj->isNative()) {
return true;
}
if (obj->as<NativeObject>().isIndexed()) {
return true;
}
if (obj->is<TypedArrayObject>()) {
return true;
}
return ClassMayResolveId(*obj->runtimeFromAnyThread()->commonNames,
obj->getClass(), INT_TO_JSID(0), obj);
}
/*
* Whether obj may have indexed properties anywhere besides its dense
* elements. This includes other indexed properties in its shape hierarchy, and
* indexed properties or elements along its prototype chain.
*/
bool js::ObjectMayHaveExtraIndexedProperties(JSObject* obj) {
MOZ_ASSERT_IF(obj->hasDynamicPrototype(), !obj->isNative());
if (ObjectMayHaveExtraIndexedOwnProperties(obj)) {
return true;
}
do {
MOZ_ASSERT(obj->hasStaticPrototype(),
"dynamic-prototype objects must be non-native, ergo must "
"have failed ObjectMayHaveExtraIndexedOwnProperties");
obj = obj->staticPrototype();
if (!obj) {
return false; // no extra indexed properties found
}
if (ObjectMayHaveExtraIndexedOwnProperties(obj)) {
return true;
}
if (obj->as<NativeObject>().getDenseInitializedLength() != 0) {
return true;
}
} while (true);
}
static bool AddLengthProperty(JSContext* cx, HandleArrayObject obj) {
// Add the 'length' property for a newly created array. Shapes are shared
// across realms within a zone and because we update the initial shape with
// a Shape that contains the length-property (in NewArray), it's possible
// the length property has already been defined.
Shape* shape = obj->lastProperty();
if (!shape->isEmptyShape()) {
MOZ_ASSERT(JSID_IS_ATOM(shape->propidRaw(), cx->names().length));
MOZ_ASSERT(shape->previous()->isEmptyShape());
return true;
}
RootedId lengthId(cx, NameToId(cx->names().length));
return NativeObject::addAccessorProperty(
cx, obj, lengthId, array_length_getter, array_length_setter,
JSPROP_PERMANENT);
}
static bool IsArrayConstructor(const JSObject* obj) {
// Note: this also returns true for cross-realm Array constructors in the
// same compartment.
return IsNativeFunction(obj, ArrayConstructor);
}
static bool IsArrayConstructor(const Value& v) {
return v.isObject() && IsArrayConstructor(&v.toObject());
}
bool js::IsCrossRealmArrayConstructor(JSContext* cx, const Value& v,
bool* result) {
if (!v.isObject()) {
*result = false;
return true;
}
JSObject* obj = &v.toObject();
if (obj->is<WrapperObject>()) {
obj = CheckedUnwrapDynamic(obj, cx);
if (!obj) {
ReportAccessDenied(cx);
return false;
}
}
*result =
IsArrayConstructor(obj) && obj->as<JSFunction>().realm() != cx->realm();
return true;
}
static MOZ_ALWAYS_INLINE bool IsArraySpecies(JSContext* cx,
HandleObject origArray) {
if (MOZ_UNLIKELY(origArray->is<ProxyObject>())) {
if (origArray->getClass()->isDOMClass()) {
#ifdef DEBUG
// We assume DOM proxies never return true for IsArray.
IsArrayAnswer answer;
MOZ_ASSERT(Proxy::isArray(cx, origArray, &answer));
MOZ_ASSERT(answer == IsArrayAnswer::NotArray);
#endif
return true;
}
return false;
}
// 9.4.2.3 Step 4. Non-array objects always use the default constructor.
if (!origArray->is<ArrayObject>()) {
return true;
}
if (cx->realm()->arraySpeciesLookup.tryOptimizeArray(
cx, &origArray->as<ArrayObject>())) {
return true;
}
Value ctor;
if (!GetPropertyPure(cx, origArray, NameToId(cx->names().constructor),
&ctor)) {
return false;
}
if (!IsArrayConstructor(ctor)) {
return ctor.isUndefined();
}
// 9.4.2.3 Step 6.c. Use the current realm's constructor if |ctor| is a
// cross-realm Array constructor.
if (cx->realm() != ctor.toObject().as<JSFunction>().realm()) {
return true;
}
jsid speciesId = SYMBOL_TO_JSID(cx->wellKnownSymbols().species);
JSFunction* getter;
if (!GetGetterPure(cx, &ctor.toObject(), speciesId, &getter)) {
return false;
}
if (!getter) {
return false;
}
return IsSelfHostedFunctionWithName(getter, cx->names().ArraySpecies);
}
static bool ArraySpeciesCreate(JSContext* cx, HandleObject origArray,
uint64_t length, MutableHandleObject arr) {
MOZ_ASSERT(length < DOUBLE_INTEGRAL_PRECISION_LIMIT);
FixedInvokeArgs<2> args(cx);
args[0].setObject(*origArray);
args[1].set(NumberValue(length));
RootedValue rval(cx);
if (!CallSelfHostedFunction(cx, cx->names().ArraySpeciesCreate,
UndefinedHandleValue, args, &rval)) {
return false;
}
MOZ_ASSERT(rval.isObject());
arr.set(&rval.toObject());
return true;
}
static bool array_toSource(JSContext* cx, unsigned argc, Value* vp) {
if (!CheckRecursionLimit(cx)) {
return false;
}
CallArgs args = CallArgsFromVp(argc, vp);
if (!args.thisv().isObject()) {
ReportIncompatible(cx, args);
return false;
}
Rooted<JSObject*> obj(cx, &args.thisv().toObject());
RootedValue elt(cx);
AutoCycleDetector detector(cx, obj);
if (!detector.init()) {
return false;
}
JSStringBuilder sb(cx);
if (detector.foundCycle()) {
if (!sb.append("[]")) {
return false;
}
goto make_string;
}
if (!sb.append('[')) {
return false;
}
uint64_t length;
if (!GetLengthProperty(cx, obj, &length)) {
return false;
}
for (uint64_t index = 0; index < length; index++) {
bool hole;
if (!CheckForInterrupt(cx) ||
!HasAndGetElement(cx, obj, index, &hole, &elt)) {
return false;
}
/* Get element's character string. */
JSString* str;
if (hole) {
str = cx->runtime()->emptyString;
} else {
str = ValueToSource(cx, elt);
if (!str) {
return false;
}
}
/* Append element to buffer. */
if (!sb.append(str)) {
return false;
}
if (index + 1 != length) {
if (!sb.append(", ")) {
return false;
}
} else if (hole) {
if (!sb.append(',')) {
return false;
}
}
}
/* Finalize the buffer. */
if (!sb.append(']')) {
return false;
}
make_string:
JSString* str = sb.finishString();
if (!str) {
return false;
}
args.rval().setString(str);
return true;
}
struct EmptySeparatorOp {
bool operator()(JSContext*, StringBuffer& sb) { return true; }
};
template <typename CharT>
struct CharSeparatorOp {
const CharT sep;
explicit CharSeparatorOp(CharT sep) : sep(sep) {}
bool operator()(JSContext*, StringBuffer& sb) { return sb.append(sep); }
};
struct StringSeparatorOp {
HandleLinearString sep;
explicit StringSeparatorOp(HandleLinearString sep) : sep(sep) {}
bool operator()(JSContext* cx, StringBuffer& sb) { return sb.append(sep); }
};
template <typename SeparatorOp>
static bool ArrayJoinDenseKernel(JSContext* cx, SeparatorOp sepOp,
HandleNativeObject obj, uint64_t length,
StringBuffer& sb, uint32_t* numProcessed) {
// This loop handles all elements up to initializedLength. If
// length > initLength we rely on the second loop to add the
// other elements.
MOZ_ASSERT(*numProcessed == 0);
uint64_t initLength = Min<uint64_t>(obj->getDenseInitializedLength(), length);
MOZ_ASSERT(initLength <= UINT32_MAX,
"initialized length shouldn't exceed UINT32_MAX");
uint32_t initLengthClamped = uint32_t(initLength);
while (*numProcessed < initLengthClamped) {
if (!CheckForInterrupt(cx)) {
return false;
}
// Step 7.b.
Value elem = obj->getDenseElement(*numProcessed);
// Steps 7.c-d.
if (elem.isString()) {
if (!sb.append(elem.toString())) {
return false;
}
} else if (elem.isNumber()) {
if (!NumberValueToStringBuffer(cx, elem, sb)) {
return false;
}
} else if (elem.isBoolean()) {
if (!BooleanToStringBuffer(elem.toBoolean(), sb)) {
return false;
}
} else if (elem.isObject() || elem.isSymbol()) {
/*
* Object stringifying could modify the initialized length or make
* the array sparse. Delegate it to a separate loop to keep this
* one tight.
*
* Symbol stringifying is a TypeError, so into the slow path
* with those as well.
*/
break;
} else if (elem.isBigInt()) {
// ToString(bigint) doesn't access bigint.toString or
// anything like that, so it can't mutate the array we're
// walking through, so it *could* be handled here. We don't
// do so yet for reasons of initial-implementation economy.
break;
} else {
MOZ_ASSERT(elem.isMagic(JS_ELEMENTS_HOLE) || elem.isNullOrUndefined());
}
// Steps 7.a, 7.e.
if (++(*numProcessed) != length && !sepOp(cx, sb)) {
return false;
}
}
return true;
}
template <typename SeparatorOp>
static bool ArrayJoinKernel(JSContext* cx, SeparatorOp sepOp, HandleObject obj,
uint64_t length, StringBuffer& sb) {
// Step 6.
uint32_t numProcessed = 0;
if (IsPackedArrayOrNoExtraIndexedProperties(obj, length)) {
if (!ArrayJoinDenseKernel<SeparatorOp>(cx, sepOp, obj.as<NativeObject>(),
length, sb, &numProcessed)) {
return false;
}
}
// Step 7.
if (numProcessed != length) {
RootedValue v(cx);
for (uint64_t i = numProcessed; i < length;) {
if (!CheckForInterrupt(cx)) {
return false;
}
// Step 7.b.
if (!GetArrayElement(cx, obj, i, &v)) {
return false;
}
// Steps 7.c-d.
if (!v.isNullOrUndefined()) {
if (!ValueToStringBuffer(cx, v, sb)) {
return false;
}
}
// Steps 7.a, 7.e.
if (++i != length && !sepOp(cx, sb)) {
return false;
}
}
}
return true;
}
// ES2017 draft rev 1b0184bc17fc09a8ddcf4aeec9b6d9fcac4eafce
// 22.1.3.13 Array.prototype.join ( separator )
bool js::array_join(JSContext* cx, unsigned argc, Value* vp) {
if (!CheckRecursionLimit(cx)) {
return false;
}
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.join", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
AutoCycleDetector detector(cx, obj);
if (!detector.init()) {
return false;
}
if (detector.foundCycle()) {
args.rval().setString(cx->names().empty);
return true;
}
// Step 2.
uint64_t length;
if (!GetLengthProperty(cx, obj, &length)) {
return false;
}
// Steps 3-4.
RootedLinearString sepstr(cx);
if (args.hasDefined(0)) {
JSString* s = ToString<CanGC>(cx, args[0]);
if (!s) {
return false;
}
sepstr = s->ensureLinear(cx);
if (!sepstr) {
return false;
}
} else {
sepstr = cx->names().comma;
}
// Steps 5-8 (When the length is zero, directly return the empty string).
if (length == 0) {
args.rval().setString(cx->emptyString());
return true;
}
// An optimized version of a special case of steps 5-8: when length==1 and
// the 0th element is a string, ToString() of that element is a no-op and
// so it can be immediately returned as the result.
if (length == 1 && obj->isNative()) {
NativeObject* nobj = &obj->as<NativeObject>();
if (nobj->getDenseInitializedLength() == 1) {
Value elem0 = nobj->getDenseElement(0);
if (elem0.isString()) {
args.rval().set(elem0);
return true;
}
}
}
// Step 5.
JSStringBuilder sb(cx);
if (sepstr->hasTwoByteChars() && !sb.ensureTwoByteChars()) {
return false;
}
// The separator will be added |length - 1| times, reserve space for that
// so that we don't have to unnecessarily grow the buffer.
size_t seplen = sepstr->length();
if (seplen > 0) {
if (length > UINT32_MAX) {
ReportAllocationOverflow(cx);
return false;
}
CheckedInt<uint32_t> res =
CheckedInt<uint32_t>(seplen) * (uint32_t(length) - 1);
if (!res.isValid()) {
ReportAllocationOverflow(cx);
return false;
}
if (!sb.reserve(res.value())) {
return false;
}
}
// Various optimized versions of steps 6-7.
if (seplen == 0) {
EmptySeparatorOp op;
if (!ArrayJoinKernel(cx, op, obj, length, sb)) {
return false;
}
} else if (seplen == 1) {
char16_t c = sepstr->latin1OrTwoByteChar(0);
if (c <= JSString::MAX_LATIN1_CHAR) {
CharSeparatorOp<Latin1Char> op(c);
if (!ArrayJoinKernel(cx, op, obj, length, sb)) {
return false;
}
} else {
CharSeparatorOp<char16_t> op(c);
if (!ArrayJoinKernel(cx, op, obj, length, sb)) {
return false;
}
}
} else {
StringSeparatorOp op(sepstr);
if (!ArrayJoinKernel(cx, op, obj, length, sb)) {
return false;
}
}
// Step 8.
JSString* str = sb.finishString();
if (!str) {
return false;
}
args.rval().setString(str);
return true;
}
// ES2017 draft rev f8a9be8ea4bd97237d176907a1e3080dce20c68f
// 22.1.3.27 Array.prototype.toLocaleString ([ reserved1 [ , reserved2 ] ])
// ES2017 Intl draft rev 78bbe7d1095f5ff3760ac4017ed366026e4cb276
// 13.4.1 Array.prototype.toLocaleString ([ locales [ , options ]])
static bool array_toLocaleString(JSContext* cx, unsigned argc, Value* vp) {
if (!CheckRecursionLimit(cx)) {
return false;
}
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
// Avoid calling into self-hosted code if the array is empty.
if (obj->is<ArrayObject>() && obj->as<ArrayObject>().length() == 0) {
args.rval().setString(cx->names().empty);
return true;
}
AutoCycleDetector detector(cx, obj);
if (!detector.init()) {
return false;
}
if (detector.foundCycle()) {
args.rval().setString(cx->names().empty);
return true;
}
FixedInvokeArgs<2> args2(cx);
args2[0].set(args.get(0));
args2[1].set(args.get(1));
// Steps 2-10.
RootedValue thisv(cx, ObjectValue(*obj));
return CallSelfHostedFunction(cx, cx->names().ArrayToLocaleString, thisv,
args2, args.rval());
}
/* vector must point to rooted memory. */
static bool SetArrayElements(
JSContext* cx, HandleObject obj, uint64_t start, uint32_t count,
const Value* vector,
ShouldUpdateTypes updateTypes = ShouldUpdateTypes::Update) {
MOZ_ASSERT(count <= MAX_ARRAY_INDEX);
MOZ_ASSERT(start + count < uint64_t(DOUBLE_INTEGRAL_PRECISION_LIMIT));
if (count == 0) {
return true;
}
if (!ObjectMayHaveExtraIndexedProperties(obj) && start <= UINT32_MAX) {
NativeObject* nobj = &obj->as<NativeObject>();
DenseElementResult result = nobj->setOrExtendDenseElements(
cx, uint32_t(start), vector, count, updateTypes);
if (result != DenseElementResult::Incomplete) {
return result == DenseElementResult::Success;
}
}
RootedId id(cx);
const Value* end = vector + count;
while (vector < end) {
if (!CheckForInterrupt(cx)) {
return false;
}
if (!ToId(cx, start++, &id)) {
return false;
}
if (!SetProperty(cx, obj, id, HandleValue::fromMarkedLocation(vector++))) {
return false;
}
}
return true;
}
static DenseElementResult ArrayReverseDenseKernel(JSContext* cx,
HandleNativeObject obj,
uint32_t length) {
MOZ_ASSERT(length > 1);
// If there are no elements, we're done.
if (obj->getDenseInitializedLength() == 0) {
return DenseElementResult::Success;
}
if (!obj->isExtensible()) {
return DenseElementResult::Incomplete;
}
if (!IsPackedArray(obj)) {
/*
* It's actually surprisingly complicated to reverse an array due
* to the orthogonality of array length and array capacity while
* handling leading and trailing holes correctly. Reversing seems
* less likely to be a common operation than other array
* mass-mutation methods, so for now just take a probably-small
* memory hit (in the absence of too many holes in the array at
* its start) and ensure that the capacity is sufficient to hold
* all the elements in the array if it were full.
*/
DenseElementResult result = obj->ensureDenseElements(cx, length, 0);
if (result != DenseElementResult::Success) {
return result;
}
/* Fill out the array's initialized length to its proper length. */
obj->ensureDenseInitializedLength(cx, length, 0);
} else {
if (!obj->maybeCopyElementsForWrite(cx)) {
return DenseElementResult::Failure;
}
}
if (!MaybeInIteration(obj, cx) && !cx->zone()->needsIncrementalBarrier()) {
obj->reverseDenseElementsNoPreBarrier(length);
return DenseElementResult::Success;
}
RootedValue origlo(cx), orighi(cx);
uint32_t lo = 0, hi = length - 1;
for (; lo < hi; lo++, hi--) {
origlo = obj->getDenseElement(lo);
orighi = obj->getDenseElement(hi);
obj->setDenseElement(lo, orighi);
if (orighi.isMagic(JS_ELEMENTS_HOLE) &&
!SuppressDeletedProperty(cx, obj, INT_TO_JSID(lo))) {
return DenseElementResult::Failure;
}
obj->setDenseElement(hi, origlo);
if (origlo.isMagic(JS_ELEMENTS_HOLE) &&
!SuppressDeletedProperty(cx, obj, INT_TO_JSID(hi))) {
return DenseElementResult::Failure;
}
}
return DenseElementResult::Success;
}
// ES2017 draft rev 1b0184bc17fc09a8ddcf4aeec9b6d9fcac4eafce
// 22.1.3.21 Array.prototype.reverse ( )
bool js::array_reverse(JSContext* cx, unsigned argc, Value* vp) {
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.reverse", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
// Step 2.
uint64_t len;
if (!GetLengthProperty(cx, obj, &len)) {
return false;
}
// An empty array or an array with length 1 is already reversed.
if (len <= 1) {
args.rval().setObject(*obj);
return true;
}
if (IsPackedArrayOrNoExtraIndexedProperties(obj, len) && len <= UINT32_MAX) {
DenseElementResult result =
ArrayReverseDenseKernel(cx, obj.as<NativeObject>(), uint32_t(len));
if (result != DenseElementResult::Incomplete) {
/*
* Per ECMA-262, don't update the length of the array, even if the new
* array has trailing holes (and thus the original array began with
* holes).
*/
args.rval().setObject(*obj);
return result == DenseElementResult::Success;
}
}
// Steps 3-5.
RootedValue lowval(cx), hival(cx);
for (uint64_t i = 0, half = len / 2; i < half; i++) {
bool hole, hole2;
if (!CheckForInterrupt(cx) ||
!HasAndGetElement(cx, obj, i, &hole, &lowval) ||
!HasAndGetElement(cx, obj, len - i - 1, &hole2, &hival)) {
return false;
}
if (!hole && !hole2) {
if (!SetArrayElement(cx, obj, i, hival)) {
return false;
}
if (!SetArrayElement(cx, obj, len - i - 1, lowval)) {
return false;
}
} else if (hole && !hole2) {
if (!SetArrayElement(cx, obj, i, hival)) {
return false;
}
if (!DeletePropertyOrThrow(cx, obj, len - i - 1)) {
return false;
}
} else if (!hole && hole2) {
if (!DeletePropertyOrThrow(cx, obj, i)) {
return false;
}
if (!SetArrayElement(cx, obj, len - i - 1, lowval)) {
return false;
}
} else {
// No action required.
}
}
// Step 6.
args.rval().setObject(*obj);
return true;
}
static inline bool CompareStringValues(JSContext* cx, const Value& a,
const Value& b, bool* lessOrEqualp) {
if (!CheckForInterrupt(cx)) {
return false;
}
JSString* astr = a.toString();
JSString* bstr = b.toString();
int32_t result;
if (!CompareStrings(cx, astr, bstr, &result)) {
return false;
}
*lessOrEqualp = (result <= 0);
return true;
}
static const uint64_t powersOf10[] = {
1, 10, 100, 1000, 10000, 100000,
1000000, 10000000, 100000000, 1000000000, 1000000000000ULL};
static inline unsigned NumDigitsBase10(uint32_t n) {
/*
* This is just floor_log10(n) + 1
* Algorithm taken from
* http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog10
*/
uint32_t log2 = CeilingLog2(n);
uint32_t t = log2 * 1233 >> 12;
return t - (n < powersOf10[t]) + 1;
}
static inline bool CompareLexicographicInt32(const Value& a, const Value& b,
bool* lessOrEqualp) {
int32_t aint = a.toInt32();
int32_t bint = b.toInt32();
/*
* If both numbers are equal ... trivial
* If only one of both is negative --> arithmetic comparison as char code
* of '-' is always less than any other digit
* If both numbers are negative convert them to positive and continue
* handling ...
*/
if (aint == bint) {
*lessOrEqualp = true;
} else if ((aint < 0) && (bint >= 0)) {
*lessOrEqualp = true;
} else if ((aint >= 0) && (bint < 0)) {
*lessOrEqualp = false;
} else {
uint32_t auint = Abs(aint);
uint32_t buint = Abs(bint);
/*
* ... get number of digits of both integers.
* If they have the same number of digits --> arithmetic comparison.
* If digits_a > digits_b: a < b*10e(digits_a - digits_b).
* If digits_b > digits_a: a*10e(digits_b - digits_a) <= b.
*/
unsigned digitsa = NumDigitsBase10(auint);
unsigned digitsb = NumDigitsBase10(buint);
if (digitsa == digitsb) {
*lessOrEqualp = (auint <= buint);
} else if (digitsa > digitsb) {
MOZ_ASSERT((digitsa - digitsb) < ArrayLength(powersOf10));
*lessOrEqualp =
(uint64_t(auint) < uint64_t(buint) * powersOf10[digitsa - digitsb]);
} else { /* if (digitsb > digitsa) */
MOZ_ASSERT((digitsb - digitsa) < ArrayLength(powersOf10));
*lessOrEqualp =
(uint64_t(auint) * powersOf10[digitsb - digitsa] <= uint64_t(buint));
}
}
return true;
}
template <typename Char1, typename Char2>
static inline bool CompareSubStringValues(JSContext* cx, const Char1* s1,
size_t len1, const Char2* s2,
size_t len2, bool* lessOrEqualp) {
if (!CheckForInterrupt(cx)) {
return false;
}
if (!s1 || !s2) {
return false;
}
int32_t result = CompareChars(s1, len1, s2, len2);
*lessOrEqualp = (result <= 0);
return true;
}
namespace {
struct SortComparatorStrings {
JSContext* const cx;
explicit SortComparatorStrings(JSContext* cx) : cx(cx) {}
bool operator()(const Value& a, const Value& b, bool* lessOrEqualp) {
return CompareStringValues(cx, a, b, lessOrEqualp);
}
};
struct SortComparatorLexicographicInt32 {
bool operator()(const Value& a, const Value& b, bool* lessOrEqualp) {
return CompareLexicographicInt32(a, b, lessOrEqualp);
}
};
struct StringifiedElement {
size_t charsBegin;
size_t charsEnd;
size_t elementIndex;
};
struct SortComparatorStringifiedElements {
JSContext* const cx;
const StringBuffer& sb;
SortComparatorStringifiedElements(JSContext* cx, const StringBuffer& sb)
: cx(cx), sb(sb) {}
bool operator()(const StringifiedElement& a, const StringifiedElement& b,
bool* lessOrEqualp) {
size_t lenA = a.charsEnd - a.charsBegin;
size_t lenB = b.charsEnd - b.charsBegin;
if (sb.isUnderlyingBufferLatin1()) {
return CompareSubStringValues(cx, sb.rawLatin1Begin() + a.charsBegin,
lenA, sb.rawLatin1Begin() + b.charsBegin,
lenB, lessOrEqualp);
}
return CompareSubStringValues(cx, sb.rawTwoByteBegin() + a.charsBegin, lenA,
sb.rawTwoByteBegin() + b.charsBegin, lenB,
lessOrEqualp);
}
};
struct NumericElement {
double dv;
size_t elementIndex;
};
static bool ComparatorNumericLeftMinusRight(const NumericElement& a,
const NumericElement& b,
bool* lessOrEqualp) {
*lessOrEqualp = (a.dv <= b.dv);
return true;
}
static bool ComparatorNumericRightMinusLeft(const NumericElement& a,
const NumericElement& b,
bool* lessOrEqualp) {
*lessOrEqualp = (b.dv <= a.dv);
return true;
}
typedef bool (*ComparatorNumeric)(const NumericElement& a,
const NumericElement& b, bool* lessOrEqualp);
static const ComparatorNumeric SortComparatorNumerics[] = {
nullptr, nullptr, ComparatorNumericLeftMinusRight,
ComparatorNumericRightMinusLeft};
static bool ComparatorInt32LeftMinusRight(const Value& a, const Value& b,
bool* lessOrEqualp) {
*lessOrEqualp = (a.toInt32() <= b.toInt32());
return true;
}
static bool ComparatorInt32RightMinusLeft(const Value& a, const Value& b,
bool* lessOrEqualp) {
*lessOrEqualp = (b.toInt32() <= a.toInt32());
return true;
}
typedef bool (*ComparatorInt32)(const Value& a, const Value& b,
bool* lessOrEqualp);
static const ComparatorInt32 SortComparatorInt32s[] = {
nullptr, nullptr, ComparatorInt32LeftMinusRight,
ComparatorInt32RightMinusLeft};
// Note: Values for this enum must match up with SortComparatorNumerics
// and SortComparatorInt32s.
enum ComparatorMatchResult {
Match_Failure = 0,
Match_None,
Match_LeftMinusRight,
Match_RightMinusLeft
};
} // namespace
/*
* Specialize behavior for comparator functions with particular common bytecode
* patterns: namely, |return x - y| and |return y - x|.
*/
static ComparatorMatchResult MatchNumericComparator(JSContext* cx,
JSObject* obj) {
if (!obj->is<JSFunction>()) {
return Match_None;
}
RootedFunction fun(cx, &obj->as<JSFunction>());
if (!fun->isInterpreted() || fun->isClassConstructor()) {
return Match_None;
}
JSScript* script = JSFunction::getOrCreateScript(cx, fun);
if (!script) {
return Match_Failure;
}
jsbytecode* pc = script->code();
uint16_t arg0, arg1;
if (JSOp(*pc) != JSOP_GETARG) {
return Match_None;
}
arg0 = GET_ARGNO(pc);
pc += JSOP_GETARG_LENGTH;
if (JSOp(*pc) != JSOP_GETARG) {
return Match_None;
}
arg1 = GET_ARGNO(pc);
pc += JSOP_GETARG_LENGTH;
if (JSOp(*pc) != JSOP_SUB) {
return Match_None;
}
pc += JSOP_SUB_LENGTH;
if (JSOp(*pc) != JSOP_RETURN) {
return Match_None;
}
if (arg0 == 0 && arg1 == 1) {
return Match_LeftMinusRight;
}
if (arg0 == 1 && arg1 == 0) {
return Match_RightMinusLeft;
}
return Match_None;
}
template <typename K, typename C>
static inline bool MergeSortByKey(K keys, size_t len, K scratch, C comparator,
MutableHandle<GCVector<Value>> vec) {
MOZ_ASSERT(vec.length() >= len);
/* Sort keys. */
if (!MergeSort(keys, len, scratch, comparator)) {
return false;
}
/*
* Reorder vec by keys in-place, going element by element. When an out-of-
* place element is encountered, move that element to its proper position,
* displacing whatever element was at *that* point to its proper position,
* and so on until an element must be moved to the current position.
*
* At each outer iteration all elements up to |i| are sorted. If
* necessary each inner iteration moves some number of unsorted elements
* (including |i|) directly to sorted position. Thus on completion |*vec|
* is sorted, and out-of-position elements have moved once. Complexity is
* Θ(len) + O(len) == O(2*len), with each element visited at most twice.
*/
for (size_t i = 0; i < len; i++) {
size_t j = keys[i].elementIndex;
if (i == j) {
continue; // fixed point
}
MOZ_ASSERT(j > i, "Everything less than |i| should be in the right place!");
Value tv = vec[j];
do {
size_t k = keys[j].elementIndex;
keys[j].elementIndex = j;
vec[j].set(vec[k]);
j = k;
} while (j != i);
// We could assert the loop invariant that |i == keys[i].elementIndex|
// here if we synced |keys[i].elementIndex|. But doing so would render
// the assertion vacuous, so don't bother, even in debug builds.
vec[i].set(tv);
}
return true;
}
/*
* Sort Values as strings.
*
* To minimize #conversions, SortLexicographically() first converts all Values
* to strings at once, then sorts the elements by these cached strings.
*/
static bool SortLexicographically(JSContext* cx,
MutableHandle<GCVector<Value>> vec,
size_t len) {
MOZ_ASSERT(vec.length() >= len);
StringBuffer sb(cx);
Vector<StringifiedElement, 0, TempAllocPolicy> strElements(cx);
/* MergeSort uses the upper half as scratch space. */
if (!strElements.resize(2 * len)) {
return false;
}
/* Convert Values to strings. */
size_t cursor = 0;
for (size_t i = 0; i < len; i++) {
if (!CheckForInterrupt(cx)) {
return false;
}
if (!ValueToStringBuffer(cx, vec[i], sb)) {
return false;
}
strElements[i] = {cursor, sb.length(), i};
cursor = sb.length();
}
/* Sort Values in vec alphabetically. */
return MergeSortByKey(strElements.begin(), len, strElements.begin() + len,
SortComparatorStringifiedElements(cx, sb), vec);
}
/*
* Sort Values as numbers.
*
* To minimize #conversions, SortNumerically first converts all Values to
* numerics at once, then sorts the elements by these cached numerics.
*/
static bool SortNumerically(JSContext* cx, MutableHandle<GCVector<Value>> vec,
size_t len, ComparatorMatchResult comp) {
MOZ_ASSERT(vec.length() >= len);
Vector<NumericElement, 0, TempAllocPolicy> numElements(cx);
/* MergeSort uses the upper half as scratch space. */
if (!numElements.resize(2 * len)) {
return false;
}
/* Convert Values to numerics. */
for (size_t i = 0; i < len; i++) {
if (!CheckForInterrupt(cx)) {
return false;
}
double dv;
if (!ToNumber(cx, vec[i], &dv)) {
return false;
}
numElements[i] = {dv, i};
}
/* Sort Values in vec numerically. */
return MergeSortByKey(numElements.begin(), len, numElements.begin() + len,
SortComparatorNumerics[comp], vec);
}
static bool FillWithUndefined(JSContext* cx, HandleObject obj, uint32_t start,
uint32_t count) {
MOZ_ASSERT(start < start + count,
"count > 0 and start + count doesn't overflow");
do {
if (ObjectMayHaveExtraIndexedProperties(obj)) {
break;
}
NativeObject* nobj = &obj->as<NativeObject>();
if (!nobj->isExtensible()) {
break;
}
if (obj->is<ArrayObject>() && !obj->as<ArrayObject>().lengthIsWritable() &&
start + count >= obj->as<ArrayObject>().length()) {
break;
}
DenseElementResult result = nobj->ensureDenseElements(cx, start, count);
if (result != DenseElementResult::Success) {
if (result == DenseElementResult::Failure) {
return false;
}
MOZ_ASSERT(result == DenseElementResult::Incomplete);
break;
}
if (obj->is<ArrayObject>() &&
start + count >= obj->as<ArrayObject>().length()) {
obj->as<ArrayObject>().setLengthInt32(start + count);
}
for (uint32_t i = 0; i < count; i++) {
nobj->setDenseElementWithType(cx, start + i, UndefinedHandleValue);
}
return true;
} while (false);
for (uint32_t i = 0; i < count; i++) {
if (!CheckForInterrupt(cx) ||
!SetArrayElement(cx, obj, start + i, UndefinedHandleValue)) {
return false;
}
}
return true;
}
bool js::intrinsic_ArrayNativeSort(JSContext* cx, unsigned argc, Value* vp) {
// This function is called from the self-hosted Array.prototype.sort
// implementation. It returns |true| if the array was sorted, otherwise it
// returns |false| to notify the self-hosted code to perform the sorting.
CallArgs args = CallArgsFromVp(argc, vp);
MOZ_ASSERT(args.length() == 1);
HandleValue fval = args[0];
MOZ_ASSERT(fval.isUndefined() || IsCallable(fval));
ComparatorMatchResult comp;
if (fval.isObject()) {
comp = MatchNumericComparator(cx, &fval.toObject());
if (comp == Match_Failure) {
return false;
}
if (comp == Match_None) {
// Non-optimized user supplied comparators perform much better when
// called from within a self-hosted sorting function.
args.rval().setBoolean(false);
return true;
}
} else {
comp = Match_None;
}
RootedObject obj(cx, &args.thisv().toObject());
uint64_t length;
if (!GetLengthProperty(cx, obj, &length)) {
return false;
}
if (length < 2) {
/* [] and [a] remain unchanged when sorted. */
args.rval().setBoolean(true);
return true;
}
if (length > UINT32_MAX) {
ReportAllocationOverflow(cx);
return false;
}
uint32_t len = uint32_t(length);
/*
* We need a temporary array of 2 * len Value to hold the array elements
* and the scratch space for merge sort. Check that its size does not
* overflow size_t, which would allow for indexing beyond the end of the
* malloc'd vector.
*/
#if JS_BITS_PER_WORD == 32
if (size_t(len) > size_t(-1) / (2 * sizeof(Value))) {
ReportAllocationOverflow(cx);
return false;
}
#endif
size_t n, undefs;
{
Rooted<GCVector<Value>> vec(cx, GCVector<Value>(cx));
if (!vec.reserve(2 * size_t(len))) {
return false;
}
/*
* By ECMA 262, 15.4.4.11, a property that does not exist (which we
* call a "hole") is always greater than an existing property with
* value undefined and that is always greater than any other property.
* Thus to sort holes and undefs we simply count them, sort the rest
* of elements, append undefs after them and then make holes after
* undefs.
*/
undefs = 0;
bool allStrings = true;
bool allInts = true;
bool extraIndexed;
RootedValue v(cx);
if (IsPackedArray(obj)) {
HandleArrayObject array = obj.as<ArrayObject>();
extraIndexed = false;
for (uint32_t i = 0; i < len; i++) {
if (!CheckForInterrupt(cx)) {
return false;
}
v.set(array->getDenseElement(i));
MOZ_ASSERT(!v.isMagic(JS_ELEMENTS_HOLE));
if (v.isUndefined()) {
++undefs;
continue;
}
vec.infallibleAppend(v);
allStrings = allStrings && v.isString();
allInts = allInts && v.isInt32();
}
} else {
extraIndexed = ObjectMayHaveExtraIndexedProperties(obj);
for (uint32_t i = 0; i < len; i++) {
if (!CheckForInterrupt(cx)) {
return false;
}
bool hole;
if (!HasAndGetElement(cx, obj, i, &hole, &v)) {
return false;
}
if (hole) {
continue;
}
if (v.isUndefined()) {
++undefs;
continue;
}
vec.infallibleAppend(v);
allStrings = allStrings && v.isString();
allInts = allInts && v.isInt32();
}
}
/*
* If the array only contains holes, we're done. But if it contains
* undefs, those must be sorted to the front of the array.
*/
n = vec.length();
if (n == 0 && undefs == 0) {
args.rval().setBoolean(true);
return true;
}
/* Here len == n + undefs + number_of_holes. */
if (comp == Match_None) {
/*
* Sort using the default comparator converting all elements to
* strings.
*/
if (allStrings) {
MOZ_ALWAYS_TRUE(vec.resize(n * 2));
if (!MergeSort(vec.begin(), n, vec.begin() + n,
SortComparatorStrings(cx))) {
return false;
}
} else if (allInts) {
MOZ_ALWAYS_TRUE(vec.resize(n * 2));
if (!MergeSort(vec.begin(), n, vec.begin() + n,
SortComparatorLexicographicInt32())) {
return false;
}
} else {
if (!SortLexicographically(cx, &vec, n)) {
return false;
}
}
} else {
if (allInts) {
MOZ_ALWAYS_TRUE(vec.resize(n * 2));
if (!MergeSort(vec.begin(), n, vec.begin() + n,
SortComparatorInt32s[comp])) {
return false;
}
} else {
if (!SortNumerically(cx, &vec, n, comp)) {
return false;
}
}
}
// We can omit the type update when neither collecting the elements
// nor calling the default comparator can execute a (getter) function
// that might run user code.
ShouldUpdateTypes updateTypes = !extraIndexed && (allStrings || allInts)
? ShouldUpdateTypes::DontUpdate
: ShouldUpdateTypes::Update;
if (!SetArrayElements(cx, obj, 0, uint32_t(n), vec.begin(), updateTypes)) {
return false;
}
}
/* Set undefs that sorted after the rest of elements. */
if (undefs > 0) {
if (!FillWithUndefined(cx, obj, n, undefs)) {
return false;
}
n += undefs;
}
/* Re-create any holes that sorted to the end of the array. */
while (len > n) {
if (!CheckForInterrupt(cx) || !DeletePropertyOrThrow(cx, obj, --len)) {
return false;
}
}
args.rval().setBoolean(true);
return true;
}
bool js::NewbornArrayPush(JSContext* cx, HandleObject obj, const Value& v) {
HandleArrayObject arr = obj.as<ArrayObject>();
MOZ_ASSERT(!v.isMagic());
MOZ_ASSERT(arr->lengthIsWritable());
uint32_t length = arr->length();
MOZ_ASSERT(length <= arr->getDenseCapacity());
if (!arr->ensureElements(cx, length + 1)) {
return false;
}
arr->setDenseInitializedLength(length + 1);
arr->setLengthInt32(length + 1);
arr->initDenseElementWithType(cx, length, v);
return true;
}
// ES2017 draft rev 1b0184bc17fc09a8ddcf4aeec9b6d9fcac4eafce
// 22.1.3.18 Array.prototype.push ( ...items )
bool js::array_push(JSContext* cx, unsigned argc, Value* vp) {
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.push", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
// Step 2.
uint64_t length;
if (!GetLengthProperty(cx, obj, &length)) {
return false;
}
if (!ObjectMayHaveExtraIndexedProperties(obj) && length <= UINT32_MAX) {
DenseElementResult result =
obj->as<NativeObject>().setOrExtendDenseElements(
cx, uint32_t(length), args.array(), args.length());
if (result != DenseElementResult::Incomplete) {
if (result == DenseElementResult::Failure) {
return false;
}
uint32_t newlength = uint32_t(length) + args.length();
args.rval().setNumber(newlength);
// setOrExtendDenseElements takes care of updating the length for
// arrays. Handle updates to the length of non-arrays here.
if (!obj->is<ArrayObject>()) {
MOZ_ASSERT(obj->is<NativeObject>());
return SetLengthProperty(cx, obj, newlength);
}
return true;
}
}
// Step 5.
uint64_t newlength = length + args.length();
if (newlength >= uint64_t(DOUBLE_INTEGRAL_PRECISION_LIMIT)) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_TOO_LONG_ARRAY);
return false;
}
// Steps 3-6.
if (!SetArrayElements(cx, obj, length, args.length(), args.array())) {
return false;
}
// Steps 7-8.
args.rval().setNumber(double(newlength));
return SetLengthProperty(cx, obj, newlength);
}
// ES2017 draft rev 1b0184bc17fc09a8ddcf4aeec9b6d9fcac4eafce
// 22.1.3.17 Array.prototype.pop ( )
bool js::array_pop(JSContext* cx, unsigned argc, Value* vp) {
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.pop", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
// Step 2.
uint64_t index;
if (!GetLengthProperty(cx, obj, &index)) {
return false;
}
// Steps 3-4.
if (index == 0) {
// Step 3.b.
args.rval().setUndefined();
} else {
// Steps 4.a-b.
index--;
// Steps 4.c, 4.f.
if (!GetArrayElement(cx, obj, index, args.rval())) {
return false;
}
// Steps 4.d.
if (!DeletePropertyOrThrow(cx, obj, index)) {
return false;
}
}
// Steps 3.a, 4.e.
return SetLengthProperty(cx, obj, index);
}
void js::ArrayShiftMoveElements(NativeObject* obj) {
AutoUnsafeCallWithABI unsafe;
MOZ_ASSERT(obj->isExtensible());
MOZ_ASSERT_IF(obj->is<ArrayObject>(),
obj->as<ArrayObject>().lengthIsWritable());
size_t initlen = obj->getDenseInitializedLength();
MOZ_ASSERT(initlen > 0);
if (!obj->tryShiftDenseElements(1)) {
obj->moveDenseElementsNoPreBarrier(0, 1, initlen - 1);
}
}
static inline void SetInitializedLength(JSContext* cx, NativeObject* obj,
size_t initlen) {
MOZ_ASSERT(obj->isExtensible());
size_t oldInitlen = obj->getDenseInitializedLength();
obj->setDenseInitializedLength(initlen);
if (initlen < oldInitlen) {
obj->shrinkElements(cx, initlen);
}
}
static DenseElementResult MoveDenseElements(JSContext* cx, NativeObject* obj,
uint32_t dstStart,
uint32_t srcStart,
uint32_t length) {
MOZ_ASSERT(obj->isExtensible());
if (!obj->maybeCopyElementsForWrite(cx)) {
return DenseElementResult::Failure;
}
obj->moveDenseElements(dstStart, srcStart, length);
return DenseElementResult::Success;
}
static DenseElementResult ArrayShiftDenseKernel(JSContext* cx, HandleObject obj,
MutableHandleValue rval) {
if (!IsPackedArray(obj) && ObjectMayHaveExtraIndexedProperties(obj)) {
return DenseElementResult::Incomplete;
}
if (MaybeInIteration(obj, cx)) {
return DenseElementResult::Incomplete;
}
if (!obj->as<NativeObject>().isExtensible()) {
return DenseElementResult::Incomplete;
}
size_t initlen = obj->as<NativeObject>().getDenseInitializedLength();
if (initlen == 0) {
return DenseElementResult::Incomplete;
}
rval.set(obj->as<NativeObject>().getDenseElement(0));
if (rval.isMagic(JS_ELEMENTS_HOLE)) {
rval.setUndefined();
}
if (obj->as<NativeObject>().tryShiftDenseElements(1)) {
return DenseElementResult::Success;
}
DenseElementResult result =
MoveDenseElements(cx, &obj->as<NativeObject>(), 0, 1, initlen - 1);
if (result != DenseElementResult::Success) {
return result;
}
SetInitializedLength(cx, obj.as<NativeObject>(), initlen - 1);
return DenseElementResult::Success;
}
// ES2017 draft rev 1b0184bc17fc09a8ddcf4aeec9b6d9fcac4eafce
// 22.1.3.22 Array.prototype.shift ( )
bool js::array_shift(JSContext* cx, unsigned argc, Value* vp) {
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.shift", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
// Step 2.
uint64_t len;
if (!GetLengthProperty(cx, obj, &len)) {
return false;
}
// Step 3.
if (len == 0) {
// Step 3.a.
if (!SetLengthProperty(cx, obj, uint32_t(0))) {
return false;
}
// Step 3.b.
args.rval().setUndefined();
return true;
}
uint64_t newlen = len - 1;
/* Fast paths. */
uint64_t startIndex;
DenseElementResult result = ArrayShiftDenseKernel(cx, obj, args.rval());
if (result != DenseElementResult::Incomplete) {
if (result == DenseElementResult::Failure) {
return false;
}
if (len <= UINT32_MAX) {
return SetLengthProperty(cx, obj, newlen);
}
startIndex = UINT32_MAX - 1;
} else {
// Steps 4, 9.
if (!GetElement(cx, obj, 0, args.rval())) {
return false;
}
startIndex = 0;
}
// Steps 5-6.
RootedValue value(cx);
for (uint64_t i = startIndex; i < newlen; i++) {
if (!CheckForInterrupt(cx)) {
return false;
}
bool hole;
if (!HasAndGetElement(cx, obj, i + 1, &hole, &value)) {
return false;
}
if (hole) {
if (!DeletePropertyOrThrow(cx, obj, i)) {
return false;
}
} else {
if (!SetArrayElement(cx, obj, i, value)) {
return false;
}
}
}
// Step 7.
if (!DeletePropertyOrThrow(cx, obj, newlen)) {
return false;
}
// Step 8.
return SetLengthProperty(cx, obj, newlen);
}
// ES2017 draft rev 1b0184bc17fc09a8ddcf4aeec9b6d9fcac4eafce
// 22.1.3.29 Array.prototype.unshift ( ...items )
bool js::array_unshift(JSContext* cx, unsigned argc, Value* vp) {
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.unshift", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
// Step 1.
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
// Step 2.
uint64_t length;
if (!GetLengthProperty(cx, obj, &length)) {
return false;
}
// Steps 3-4.
if (args.length() > 0) {
bool optimized = false;
do {
if (length > UINT32_MAX) {
break;
}
if (ObjectMayHaveExtraIndexedProperties(obj)) {
break;
}
if (MaybeInIteration(obj, cx)) {
break;
}
NativeObject* nobj = &obj->as<NativeObject>();
if (!nobj->isExtensible()) {
break;
}
if (nobj->is<ArrayObject>() &&
!nobj->as<ArrayObject>().lengthIsWritable()) {
break;
}
if (!nobj->tryUnshiftDenseElements(args.length())) {
DenseElementResult result =
nobj->ensureDenseElements(cx, uint32_t(length), args.length());
if (result != DenseElementResult::Success) {
if (result == DenseElementResult::Failure) {
return false;
}
MOZ_ASSERT(result == DenseElementResult::Incomplete);
break;
}
if (length > 0) {
nobj->moveDenseElements(args.length(), 0, uint32_t(length));
}
}
for (uint32_t i = 0; i < args.length(); i++) {
nobj->setDenseElementWithType(cx, i, args[i]);
}
optimized = true;
} while (false);
if (!optimized) {
if (length > 0) {
uint64_t last = length;
uint64_t upperIndex = last + args.length();
// Step 4.a.
if (upperIndex >= uint64_t(DOUBLE_INTEGRAL_PRECISION_LIMIT)) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_TOO_LONG_ARRAY);
return false;
}
// Steps 4.b-c.
RootedValue value(cx);
do {
--last;
--upperIndex;
if (!CheckForInterrupt(cx)) {
return false;
}
bool hole;
if (!HasAndGetElement(cx, obj, last, &hole, &value)) {
return false;
}
if (hole) {
if (!DeletePropertyOrThrow(cx, obj, upperIndex)) {
return false;
}
} else {
if (!SetArrayElement(cx, obj, upperIndex, value)) {
return false;
}
}
} while (last != 0);
}
// Steps 4.d-f.
/* Copy from args to the bottom of the array. */
if (!SetArrayElements(cx, obj, 0, args.length(), args.array())) {
return false;
}
}
}
// Step 5.
uint64_t newlength = length + args.length();
if (!SetLengthProperty(cx, obj, newlength)) {
return false;
}
// Step 6.
/* Follow Perl by returning the new array length. */
args.rval().setNumber(double(newlength));
return true;
}
enum class ArrayAccess { Read, Write };
/*
* Returns true if this is a dense array whose properties ending at |endIndex|
* (exclusive) may be accessed (get, set, delete) directly through its
* contiguous vector of elements without fear of getters, setters, etc. along
* the prototype chain, or of enumerators requiring notification of
* modifications.
*/
template <ArrayAccess Access>
static bool CanOptimizeForDenseStorage(HandleObject arr, uint64_t endIndex,
JSContext* cx) {
/* If the desired properties overflow dense storage, we can't optimize. */
if (endIndex > UINT32_MAX) {
return false;
}
if (Access == ArrayAccess::Read) {
/*
* Dense storage read access is possible for any packed array as long
* as we only access properties within the initialized length. In all
* other cases we need to ensure there are no other indexed properties
* on this object or on the prototype chain. Callers are required to
* clamp the read length, so it doesn't exceed the initialized length.
*/
if (IsPackedArray(arr) &&
endIndex <= arr->as<ArrayObject>().getDenseInitializedLength()) {
return true;
}
return !ObjectMayHaveExtraIndexedProperties(arr);
}
/* There's no optimizing possible if it's not an array. */
if (!arr->is<ArrayObject>()) {
return false;
}
/* If the length is non-writable, always pick the slow path */
if (!arr->as<ArrayObject>().lengthIsWritable()) {
return false;
}
/* Also pick the slow path if the object is non-extensible. */
if (!arr->as<ArrayObject>().isExtensible()) {
return false;
}
/* Also pick the slow path if the object is being iterated over. */
if (MaybeInIteration(arr, cx)) {
return false;
}
/* Or we attempt to write to indices outside the initialized length. */
if (endIndex > arr->as<ArrayObject>().getDenseInitializedLength()) {
return false;
}
/*
* Now watch out for getters and setters along the prototype chain or in
* other indexed properties on the object. Packed arrays don't have any
* other indexed properties by definition.
*/
return IsPackedArray(arr) || !ObjectMayHaveExtraIndexedProperties(arr);
}
static ArrayObject* CopyDenseArrayElements(JSContext* cx,
HandleNativeObject obj,
uint32_t begin, uint32_t count) {
size_t initlen = obj->getDenseInitializedLength();
MOZ_ASSERT(initlen <= UINT32_MAX,
"initialized length shouldn't exceed UINT32_MAX");
uint32_t newlength = 0;
if (initlen > begin) {
newlength = Min<uint32_t>(initlen - begin, count);
}
ArrayObject* narr = NewFullyAllocatedArrayTryReuseGroup(cx, obj, newlength);
if (!narr) {
return nullptr;
}
MOZ_ASSERT(count >= narr->length());
narr->setLength(cx, count);
if (newlength > 0) {
narr->initDenseElements(obj, begin, newlength);
}
return narr;
}
static bool CopyArrayElements(JSContext* cx, HandleObject obj, uint64_t begin,
uint64_t count, HandleArrayObject result) {
MOZ_ASSERT(result->length() == count);
uint64_t startIndex = 0;
RootedValue value(cx);
// Use dense storage for new indexed properties where possible.
{
uint32_t index = 0;
uint32_t limit = Min<uint32_t>(count, JSID_INT_MAX);
for (; index < limit; index++) {
bool hole;
if (!CheckForInterrupt(cx) ||
!HasAndGetElement(cx, obj, begin + index, &hole, &value)) {
return false;
}
if (!hole) {
DenseElementResult edResult = result->ensureDenseElements(cx, index, 1);
if (edResult != DenseElementResult::Success) {
if (edResult == DenseElementResult::Failure) {
return false;
}
MOZ_ASSERT(edResult == DenseElementResult::Incomplete);
if (!DefineDataElement(cx, result, index, value)) {
return false;
}
break;
}
result->setDenseElementWithType(cx, index, value);
}
}
startIndex = index + 1;
}
// Copy any remaining elements.
for (uint64_t i = startIndex; i < count; i++) {
bool hole;
if (!CheckForInterrupt(cx) ||
!HasAndGetElement(cx, obj, begin + i, &hole, &value)) {
return false;
}
if (!hole && !DefineArrayElement(cx, result, i, value)) {
return false;
}
}
return true;
}
static bool array_splice_impl(JSContext* cx, unsigned argc, Value* vp,
bool returnValueIsUsed) {
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.splice", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
/* Step 1. */
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
/* Step 2. */
uint64_t len;
if (!GetLengthProperty(cx, obj, &len)) {
return false;
}
/* Step 3. */
double relativeStart;
if (!ToInteger(cx, args.get(0), &relativeStart)) {
return false;
}
/* Step 4. */
uint64_t actualStart;
if (relativeStart < 0) {
actualStart = Max(len + relativeStart, 0.0);
} else {
actualStart = Min(relativeStart, double(len));
}
/* Step 5. */
uint64_t actualDeleteCount;
if (args.length() == 0) {
/* Step 5.b. */
actualDeleteCount = 0;
} else if (args.length() == 1) {
/* Step 6.b. */
actualDeleteCount = len - actualStart;
} else {
/* Steps 7.b. */
double deleteCountDouble;
if (!ToInteger(cx, args[1], &deleteCountDouble)) {
return false;
}
/* Step 7.c. */
actualDeleteCount =
Min(Max(deleteCountDouble, 0.0), double(len - actualStart));
/* Step 8. */
uint32_t insertCount = args.length() - 2;
if (len + insertCount - actualDeleteCount >=
DOUBLE_INTEGRAL_PRECISION_LIMIT) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_TOO_LONG_ARRAY);
return false;
}
}
MOZ_ASSERT(actualStart + actualDeleteCount <= len);
RootedObject arr(cx);
if (IsArraySpecies(cx, obj)) {
if (actualDeleteCount > UINT32_MAX) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_BAD_ARRAY_LENGTH);
return false;
}
uint32_t count = uint32_t(actualDeleteCount);
if (CanOptimizeForDenseStorage<ArrayAccess::Read>(obj, actualStart + count,
cx)) {
MOZ_ASSERT(actualStart <= UINT32_MAX,
"if actualStart + count <= UINT32_MAX, then actualStart <= "
"UINT32_MAX");
if (returnValueIsUsed) {
/* Steps 9-12. */
arr = CopyDenseArrayElements(cx, obj.as<NativeObject>(),
uint32_t(actualStart), count);
if (!arr) {
return false;
}
}
} else {
/* Step 9. */
arr = NewFullyAllocatedArrayTryReuseGroup(cx, obj, count);
if (!arr) {
return false;
}
/* Steps 10-11. */
if (!CopyArrayElements(cx, obj, actualStart, count,
arr.as<ArrayObject>())) {
return false;
}
/* Step 12 (implicit). */
}
} else {
/* Steps 9. */
if (!ArraySpeciesCreate(cx, obj, actualDeleteCount, &arr)) {
return false;
}
/* Steps 10, 11, 11.d. */
RootedValue fromValue(cx);
for (uint64_t k = 0; k < actualDeleteCount; k++) {
/* Step 11.a (implicit). */
if (!CheckForInterrupt(cx)) {
return false;
}
/* Steps 11.b, 11.c.i. */
bool hole;
if (!HasAndGetElement(cx, obj, actualStart + k, &hole, &fromValue)) {
return false;
}
/* Step 11.c. */
if (!hole) {
/* Step 11.c.ii. */
if (!DefineArrayElement(cx, arr, k, fromValue)) {
return false;
}
}
}
/* Step 12. */
if (!SetLengthProperty(cx, arr, actualDeleteCount)) {
return false;
}
}
/* Step 14. */
uint32_t itemCount = (args.length() >= 2) ? (args.length() - 2) : 0;
uint64_t finalLength = len - actualDeleteCount + itemCount;
if (itemCount < actualDeleteCount) {
/* Step 15: the array is being shrunk. */
uint64_t sourceIndex = actualStart + actualDeleteCount;
uint64_t targetIndex = actualStart + itemCount;
if (CanOptimizeForDenseStorage<ArrayAccess::Write>(obj, len, cx)) {
MOZ_ASSERT(sourceIndex <= len && targetIndex <= len && len <= UINT32_MAX,
"sourceIndex and targetIndex are uint32 array indices");
MOZ_ASSERT(finalLength < len, "finalLength is strictly less than len");
MOZ_ASSERT(obj->isNative());
/* Steps 15.a-b. */
if (targetIndex != 0 ||
!obj->as<NativeObject>().tryShiftDenseElements(sourceIndex)) {
DenseElementResult result = MoveDenseElements(
cx, &obj->as<NativeObject>(), uint32_t(targetIndex),
uint32_t(sourceIndex), uint32_t(len - sourceIndex));
MOZ_ASSERT(result != DenseElementResult::Incomplete);
if (result == DenseElementResult::Failure) {
return false;
}
}
/* Steps 15.c-d. */
SetInitializedLength(cx, obj.as<NativeObject>(), finalLength);
} else {
/*
* This is all very slow if the length is very large. We don't yet
* have the ability to iterate in sorted order, so we just do the
* pessimistic thing and let CheckForInterrupt handle the
* fallout.
*/
/* Steps 15.a-b. */
RootedValue fromValue(cx);
for (uint64_t from = sourceIndex, to = targetIndex; from < len;
from++, to++) {
/* Steps 15.b.i-ii (implicit). */
if (!CheckForInterrupt(cx)) {
return false;
}
/* Steps 15.b.iii, 15.b.iv.1. */
bool hole;
if (!HasAndGetElement(cx, obj, from, &hole, &fromValue)) {
return false;
}
/* Steps 15.b.iv. */
if (hole) {
/* Steps 15.b.v.1. */
if (!DeletePropertyOrThrow(cx, obj, to)) {
return false;
}
} else {
/* Step 15.b.iv.2. */
if (!SetArrayElement(cx, obj, to, fromValue)) {
return false;
}
}
}
/* Steps 15.c-d. */
if (!DeletePropertiesOrThrow(cx, obj, len, finalLength)) {
return false;
}
}
} else if (itemCount > actualDeleteCount) {
MOZ_ASSERT(actualDeleteCount <= UINT32_MAX);
uint32_t deleteCount = uint32_t(actualDeleteCount);
/* Step 16. */
/*
* Optimize only if the array is already dense and we can extend it to
* its new length. It would be wrong to extend the elements here for a
* number of reasons.
*
* First, this could cause us to fall into the fast-path below. This
* would cause elements to be moved into places past the non-writable
* length. And when the dense initialized length is updated, that'll
* cause the |in| operator to think that those elements actually exist,
* even though, properly, setting them must fail.
*
* Second, extending the elements here will trigger assertions inside
* ensureDenseElements that the elements aren't being extended past the
* length of a non-writable array. This is because extending elements
* will extend capacity -- which might extend them past a non-writable
* length, violating the |capacity <= length| invariant for such
* arrays. And that would make the various JITted fast-path method
* implementations of [].push, [].unshift, and so on wrong.
*
* If the array length is non-writable, this method *will* throw. For
* simplicity, have the slow-path code do it. (Also note that the slow
* path may validly *not* throw -- if all the elements being moved are
* holes.)
*/
if (obj->is<ArrayObject>() && !ObjectMayHaveExtraIndexedProperties(obj) &&
len <= UINT32_MAX) {
HandleArrayObject arr = obj.as<ArrayObject>();
if (arr->lengthIsWritable() && arr->isExtensible()) {
DenseElementResult result = arr->ensureDenseElements(
cx, uint32_t(len), itemCount - deleteCount);
if (result == DenseElementResult::Failure) {
return false;
}
}
}
if (CanOptimizeForDenseStorage<ArrayAccess::Write>(obj, finalLength, cx)) {
MOZ_ASSERT((actualStart + actualDeleteCount) <= len && len <= UINT32_MAX,
"start and deleteCount are uint32 array indices");
MOZ_ASSERT(actualStart + itemCount <= UINT32_MAX,
"can't overflow because |len - actualDeleteCount + itemCount "
"<= UINT32_MAX| "
"and |actualStart <= len - actualDeleteCount| are both true");
uint32_t start = uint32_t(actualStart);
uint32_t length = uint32_t(len);
DenseElementResult result = MoveDenseElements(
cx, &obj->as<NativeObject>(), start + itemCount, start + deleteCount,
length - (start + deleteCount));
MOZ_ASSERT(result != DenseElementResult::Incomplete);
if (result == DenseElementResult::Failure) {
return false;
}
/* Steps 16.a-b. */
SetInitializedLength(cx, obj.as<NativeObject>(), finalLength);
} else {
RootedValue fromValue(cx);
for (uint64_t k = len - actualDeleteCount; k > actualStart; k--) {
if (!CheckForInterrupt(cx)) {
return false;
}
/* Step 16.b.i. */
uint64_t from = k + actualDeleteCount - 1;
/* Step 16.b.ii. */
uint64_t to = k + itemCount - 1;
/* Steps 16.b.iii, 16.b.iv.1. */
bool hole;
if (!HasAndGetElement(cx, obj, from, &hole, &fromValue)) {
return false;
}
/* Steps 16.b.iv. */
if (hole) {
/* Step 16.b.v.1. */
if (!DeletePropertyOrThrow(cx, obj, to)) {
return false;
}
} else {
/* Step 16.b.iv.2. */
if (!SetArrayElement(cx, obj, to, fromValue)) {
return false;
}
}
}
}
}
/* Step 13 (reordered). */
Value* items = args.array() + 2;
/* Steps 17-18. */
if (!SetArrayElements(cx, obj, actualStart, itemCount, items)) {
return false;
}
/* Step 19. */
if (!SetLengthProperty(cx, obj, finalLength)) {
return false;
}
/* Step 20. */
if (returnValueIsUsed) {
args.rval().setObject(*arr);
}
return true;
}
/* ES 2016 draft Mar 25, 2016 22.1.3.26. */
bool js::array_splice(JSContext* cx, unsigned argc, Value* vp) {
return array_splice_impl(cx, argc, vp, true);
}
static bool array_splice_noRetVal(JSContext* cx, unsigned argc, Value* vp) {
return array_splice_impl(cx, argc, vp, false);
}
struct SortComparatorIndexes {
bool operator()(uint32_t a, uint32_t b, bool* lessOrEqualp) {
*lessOrEqualp = (a <= b);
return true;
}
};
// Returns all indexed properties in the range [begin, end) found on |obj| or
// its proto chain. This function does not handle proxies, objects with
// resolve/lookupProperty hooks or indexed getters, as those can introduce
// new properties. In those cases, *success is set to |false|.
static bool GetIndexedPropertiesInRange(JSContext* cx, HandleObject obj,
uint64_t begin, uint64_t end,
Vector<uint32_t>& indexes,
bool* success) {
*success = false;
// TODO: Add IdIsIndex with support for large indices.
if (end > UINT32_MAX) {
return true;
}
MOZ_ASSERT(begin <= UINT32_MAX);
// First, look for proxies or class hooks that can introduce extra
// properties.
JSObject* pobj = obj;
do {
if (!pobj->isNative() || pobj->getClass()->getResolve() ||
pobj->getOpsLookupProperty()) {
return true;
}
} while ((pobj = pobj->staticPrototype()));
// Collect indexed property names.
pobj = obj;
do {
// Append dense elements.
NativeObject* nativeObj = &pobj->as<NativeObject>();
uint32_t initLen = nativeObj->getDenseInitializedLength();
for (uint32_t i = begin; i < initLen && i < end; i++) {
if (nativeObj->getDenseElement(i).isMagic(JS_ELEMENTS_HOLE)) {
continue;
}
if (!indexes.append(i)) {
return false;
}
}
// Append typed array elements.
if (nativeObj->is<TypedArrayObject>()) {
uint32_t len = nativeObj->as<TypedArrayObject>().length();
for (uint32_t i = begin; i < len && i < end; i++) {
if (!indexes.append(i)) {
return false;
}
}
}
// Append sparse elements.
if (nativeObj->isIndexed()) {
Shape::Range<NoGC> r(nativeObj->lastProperty());
for (; !r.empty(); r.popFront()) {
Shape& shape = r.front();
jsid id = shape.propid();
uint32_t i;
if (!IdIsIndex(id, &i)) {
continue;
}
if (!(begin <= i && i < end)) {
continue;
}
// Watch out for getters, they can add new properties.
if (!shape.hasDefaultGetter()) {
return true;
}
if (!indexes.append(i)) {
return false;
}
}
}
} while ((pobj = pobj->staticPrototype()));
// Sort the indexes.
Vector<uint32_t> tmp(cx);
size_t n = indexes.length();
if (!tmp.resize(n)) {
return false;
}
if (!MergeSort(indexes.begin(), n, tmp.begin(), SortComparatorIndexes())) {
return false;
}
// Remove duplicates.
if (!indexes.empty()) {
uint32_t last = 0;
for (size_t i = 1, len = indexes.length(); i < len; i++) {
uint32_t elem = indexes[i];
if (indexes[last] != elem) {
last++;
indexes[last] = elem;
}
}
if (!indexes.resize(last + 1)) {
return false;
}
}
*success = true;
return true;
}
static bool SliceSparse(JSContext* cx, HandleObject obj, uint64_t begin,
uint64_t end, HandleArrayObject result) {
MOZ_ASSERT(begin <= end);
Vector<uint32_t> indexes(cx);
bool success;
if (!GetIndexedPropertiesInRange(cx, obj, begin, end, indexes, &success)) {
return false;
}
if (!success) {
return CopyArrayElements(cx, obj, begin, end - begin, result);
}
MOZ_ASSERT(end <= UINT32_MAX,
"indices larger than UINT32_MAX should be rejected by "
"GetIndexedPropertiesInRange");
RootedValue value(cx);
for (uint32_t index : indexes) {
MOZ_ASSERT(begin <= index && index < end);
bool hole;
if (!HasAndGetElement(cx, obj, index, &hole, &value)) {
return false;
}
if (!hole &&
!DefineDataElement(cx, result, index - uint32_t(begin), value)) {
return false;
}
}
return true;
}
static JSObject* SliceArguments(JSContext* cx, Handle<ArgumentsObject*> argsobj,
uint32_t begin, uint32_t count) {
MOZ_ASSERT(!argsobj->hasOverriddenLength() &&
!argsobj->isAnyElementDeleted());
MOZ_ASSERT(begin + count <= argsobj->initialLength());
ArrayObject* result = NewDenseFullyAllocatedArray(cx, count);
if (!result) {
return nullptr;
}
result->setDenseInitializedLength(count);
MOZ_ASSERT(result->group()->unknownPropertiesDontCheckGeneration(),
"The default array group has unknown properties, so we can "
"directly initialize the"
"dense elements without needing to update the indexed type set.");
for (uint32_t index = 0; index < count; index++) {
const Value& v = argsobj->element(begin + index);
result->initDenseElement(index, v);
}
return result;
}
template <typename T, typename ArrayLength>
static inline ArrayLength NormalizeSliceTerm(T value, ArrayLength length) {
if (value < 0) {
value += length;
if (value < 0) {
return 0;
}
} else if (double(value) > double(length)) {
return length;
}
return ArrayLength(value);
}
static bool ArraySliceOrdinary(JSContext* cx, HandleObject obj, uint64_t begin,
uint64_t end, MutableHandleValue rval) {
if (begin > end) {
begin = end;
}
if ((end - begin) > UINT32_MAX) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_BAD_ARRAY_LENGTH);
return false;
}
uint32_t count = uint32_t(end - begin);
if (CanOptimizeForDenseStorage<ArrayAccess::Read>(obj, end, cx)) {
MOZ_ASSERT(begin <= UINT32_MAX,
"if end <= UINT32_MAX, then begin <= UINT32_MAX");
JSObject* narr = CopyDenseArrayElements(cx, obj.as<NativeObject>(),
uint32_t(begin), count);
if (!narr) {
return false;
}
rval.setObject(*narr);
return true;
}
if (obj->is<ArgumentsObject>()) {
Handle<ArgumentsObject*> argsobj = obj.as<ArgumentsObject>();
if (!argsobj->hasOverriddenLength() && !argsobj->isAnyElementDeleted()) {
MOZ_ASSERT(begin <= UINT32_MAX, "begin is limited by |argsobj|'s length");
JSObject* narr = SliceArguments(cx, argsobj, uint32_t(begin), count);
if (!narr) {
return false;
}
rval.setObject(*narr);
return true;
}
}
RootedArrayObject narr(cx,
NewPartlyAllocatedArrayTryReuseGroup(cx, obj, count));
if (!narr) {
return false;
}
if (end <= UINT32_MAX) {
if (js::GetElementsOp op = obj->getOpsGetElements()) {
ElementAdder adder(cx, narr, count,
ElementAdder::CheckHasElemPreserveHoles);
if (!op(cx, obj, uint32_t(begin), uint32_t(end), &adder)) {
return false;
}
rval.setObject(*narr);
return true;
}
}
if (obj->isNative() && obj->as<NativeObject>().isIndexed() && count > 1000) {
if (!SliceSparse(cx, obj, begin, end, narr)) {
return false;
}
} else {
if (!CopyArrayElements(cx, obj, begin, count, narr)) {
return false;
}
}
rval.setObject(*narr);
return true;
}
/* ES 2016 draft Mar 25, 2016 22.1.3.23. */
bool js::array_slice(JSContext* cx, unsigned argc, Value* vp) {
AutoGeckoProfilerEntry pseudoFrame(
cx, "Array.prototype.slice", JS::ProfilingCategoryPair::JS,
uint32_t(ProfilingStackFrame::Flags::RELEVANT_FOR_JS));
CallArgs args = CallArgsFromVp(argc, vp);
/* Step 1. */
RootedObject obj(cx, ToObject(cx, args.thisv()));
if (!obj) {
return false;
}
/* Step 2. */
uint64_t length;
if (!GetLengthProperty(cx, obj, &length)) {
return false;
}
uint64_t k = 0;
uint64_t final = length;
if (args.length() > 0) {
double d;
/* Step 3. */
if (!ToInteger(cx, args[0], &d)) {
return false;
}
/* Step 4. */
k = NormalizeSliceTerm(d, length);
if (args.hasDefined(1)) {
/* Step 5. */
if (!ToInteger(cx, args[1], &d)) {
return false;
}
/* Step 6. */
final = NormalizeSliceTerm(d, length);
}
}
if (IsArraySpecies(cx, obj)) {
/* Steps 7-12: Optimized for ordinary array. */
return ArraySliceOrdinary(cx, obj, k, final, args.rval());
}
/* Step 7. */
uint64_t count = final > k ? final - k : 0;
/* Step 8. */
RootedObject arr(cx);
if (!ArraySpeciesCreate(cx, obj, count, &arr)) {
return false;
}
/* Step 9. */
uint64_t n = 0;
/* Step 10. */
RootedValue kValue(cx);
while (k < final) {
if (!CheckForInterrupt(cx)) {
return false;
}
/* Steps 10.a-b, and 10.c.i. */
bool kNotPresent;
if (!HasAndGetElement(cx, obj, k, &kNotPresent, &kValue)) {
return false;
}
/* Step 10.c. */
if (!kNotPresent) {
/* Steps 10.c.ii. */
if (!DefineArrayElement(cx, arr, n, kValue)) {
return false;
}
}
/* Step 10.d. */
k++;
/* Step 10.e. */
n++;
}
/* Step 11. */
if (!SetLengthProperty(cx, arr, n)) {
return false;
}
/* Step 12. */
args.rval().setObject(*arr);
return true;
}
static bool ArraySliceDenseKernel(JSContext* cx, ArrayObject* arr,
int32_t beginArg, int32_t endArg,
ArrayObject* result) {
uint32_t length = arr->length();
uint32_t begin = NormalizeSliceTerm(beginArg, length);
uint32_t end = NormalizeSliceTerm(endArg, length);
if (begin > end) {
begin = end;
}
uint32_t count = end - begin;
size_t initlen = arr->getDenseInitializedLength();
if (initlen > begin) {
uint32_t newlength = Min<uint32_t>(initlen - begin, count);
if (newlength > 0) {
if (!result->ensureElements(cx, newlength)) {
return false;
}
result->initDenseElements(arr, begin, newlength);
}
}
MOZ_ASSERT(count >= result->length());
result->setLength(cx, count);
return true;
}
JSObject* js::ArraySliceDense(JSContext* cx, HandleObject obj, int32_t begin,
int32_t end, HandleObject result) {
if (result && IsArraySpecies(cx, obj)) {
if (!ArraySliceDenseKernel(cx, &obj->as<ArrayObject>(), begin, end,
&result->as<ArrayObject>())) {
return nullptr;
}
return result;
}
// Slower path if the JIT wasn't able to allocate an object inline.
JS::AutoValueArray<4> argv(cx);
argv[0].setUndefined();
argv[1].setObject(*obj);
argv[2].setInt32(begin);
argv[3].setInt32(end);
if (!array_slice(cx, 2, argv.begin())) {
return nullptr;
}
return &argv[0].toObject();
}
static bool array_isArray(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
bool isArray = false;
if (args.get(0).isObject()) {
RootedObject obj(cx, &args[0].toObject());
if (!IsArray(cx, obj, &isArray)) {
return false;
}
}
args.rval().setBoolean(isArray);
return true;
}
static bool ArrayFromCallArgs(JSContext* cx, CallArgs& args,
HandleObject proto = nullptr) {
ArrayObject* obj = NewCopiedArrayForCallingAllocationSite(
cx, args.array(), args.length(), proto);
if (!obj) {
return false;
}
args.rval().setObject(*obj);
return true;
}
static bool array_of(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
bool isArrayConstructor =
IsArrayConstructor(args.thisv()) &&
args.thisv().toObject().nonCCWRealm() == cx->realm();
if (isArrayConstructor || !IsConstructor(args.thisv())) {
// isArrayConstructor will usually be true in practice. This is the most
// common path.
return ArrayFromCallArgs(cx, args);
}
// Step 4.
RootedObject obj(cx);
{
FixedConstructArgs<1> cargs(cx);
cargs[0].setNumber(args.length());
if (!Construct(cx, args.thisv(), cargs, args.thisv(), &obj)) {
return false;
}
}
// Step 8.
for (unsigned k = 0; k < args.length(); k++) {
if (!DefineDataElement(cx, obj, k, args[k])) {
return false;
}
}
// Steps 9-10.
if (!SetLengthProperty(cx, obj, args.length())) {
return false;
}
// Step 11.
args.rval().setObject(*obj);
return true;
}
const JSJitInfo js::array_splice_info = {
{(JSJitGetterOp)array_splice_noRetVal},
{0}, /* unused */
{0}, /* unused */
JSJitInfo::IgnoresReturnValueNative,
JSJitInfo::AliasEverything,
JSVAL_TYPE_UNDEFINED,
};
static const JSFunctionSpec array_methods[] = {
JS_FN(js_toSource_str, array_toSource, 0, 0),
JS_SELF_HOSTED_FN(js_toString_str, "ArrayToString", 0, 0),
JS_FN(js_toLocaleString_str, array_toLocaleString, 0, 0),
/* Perl-ish methods. */
JS_INLINABLE_FN("join", array_join, 1, 0, ArrayJoin),
JS_FN("reverse", array_reverse, 0, 0),
JS_SELF_HOSTED_FN("sort", "ArraySort", 1, 0),
JS_INLINABLE_FN("push", array_push, 1, 0, ArrayPush),
JS_INLINABLE_FN("pop", array_pop, 0, 0, ArrayPop),
JS_INLINABLE_FN("shift", array_shift, 0, 0, ArrayShift),
JS_FN("unshift", array_unshift, 1, 0),
JS_FNINFO("splice", array_splice, &array_splice_info, 2, 0),
/* Pythonic sequence methods. */
JS_SELF_HOSTED_FN("concat", "ArrayConcat", 1, 0),
JS_INLINABLE_FN("slice", array_slice, 2, 0, ArraySlice),
JS_SELF_HOSTED_FN("lastIndexOf", "ArrayLastIndexOf", 1, 0),
JS_SELF_HOSTED_FN("indexOf", "ArrayIndexOf", 1, 0),
JS_SELF_HOSTED_FN("forEach", "ArrayForEach", 1, 0),
JS_SELF_HOSTED_FN("map", "ArrayMap", 1, 0),
JS_SELF_HOSTED_FN("filter", "ArrayFilter", 1, 0),
JS_SELF_HOSTED_FN("reduce", "ArrayReduce", 1, 0),
JS_SELF_HOSTED_FN("reduceRight", "ArrayReduceRight", 1, 0),
JS_SELF_HOSTED_FN("some", "ArraySome", 1, 0),
JS_SELF_HOSTED_FN("every", "ArrayEvery", 1, 0),
/* ES6 additions */
JS_SELF_HOSTED_FN("find", "ArrayFind", 1, 0),
JS_SELF_HOSTED_FN("findIndex", "ArrayFindIndex", 1, 0),
JS_SELF_HOSTED_FN("copyWithin", "ArrayCopyWithin", 3, 0),
JS_SELF_HOSTED_FN("fill", "ArrayFill", 3, 0),
JS_SELF_HOSTED_SYM_FN(iterator, "ArrayValues", 0, 0),
JS_SELF_HOSTED_FN("entries", "ArrayEntries", 0, 0),
JS_SELF_HOSTED_FN("keys", "ArrayKeys", 0, 0),
JS_SELF_HOSTED_FN("values", "ArrayValues", 0, 0),
/* ES7 additions */
JS_SELF_HOSTED_FN("includes", "ArrayIncludes", 2, 0),
/* Future additions */
JS_SELF_HOSTED_FN("flatMap", "ArrayFlatMap", 1, 0),
JS_SELF_HOSTED_FN("flat", "ArrayFlat", 0, 0),
JS_FS_END};
static const JSFunctionSpec array_static_methods[] = {
JS_INLINABLE_FN("isArray", array_isArray, 1, 0, ArrayIsArray),
JS_SELF_HOSTED_FN("concat", "ArrayStaticConcat", 2, 0),
JS_SELF_HOSTED_FN("lastIndexOf", "ArrayStaticLastIndexOf", 2, 0),
JS_SELF_HOSTED_FN("indexOf", "ArrayStaticIndexOf", 2, 0),
JS_SELF_HOSTED_FN("forEach", "ArrayStaticForEach", 2, 0),
JS_SELF_HOSTED_FN("map", "ArrayStaticMap", 2, 0),
JS_SELF_HOSTED_FN("filter", "ArrayStaticFilter", 2, 0),
JS_SELF_HOSTED_FN("every", "ArrayStaticEvery", 2, 0),
JS_SELF_HOSTED_FN("some", "ArrayStaticSome", 2, 0),
JS_SELF_HOSTED_FN("reduce", "ArrayStaticReduce", 2, 0),
JS_SELF_HOSTED_FN("reduceRight", "ArrayStaticReduceRight", 2, 0),
JS_SELF_HOSTED_FN("join", "ArrayStaticJoin", 2, 0),
JS_SELF_HOSTED_FN("reverse", "ArrayStaticReverse", 1, 0),
JS_SELF_HOSTED_FN("sort", "ArrayStaticSort", 2, 0),
JS_SELF_HOSTED_FN("push", "ArrayStaticPush", 2, 0),
JS_SELF_HOSTED_FN("pop", "ArrayStaticPop", 1, 0),
JS_SELF_HOSTED_FN("shift", "ArrayStaticShift", 1, 0),
JS_SELF_HOSTED_FN("unshift", "ArrayStaticUnshift", 2, 0),
JS_SELF_HOSTED_FN("splice", "ArrayStaticSplice", 3, 0),
JS_SELF_HOSTED_FN("slice", "ArrayStaticSlice", 3, 0),
JS_SELF_HOSTED_FN("from", "ArrayFrom", 3, 0),
JS_FN("of", array_of, 0, 0),
JS_FS_END};
const JSPropertySpec array_static_props[] = {
JS_SELF_HOSTED_SYM_GET(species, "ArraySpecies", 0), JS_PS_END};
static inline bool ArrayConstructorImpl(JSContext* cx, CallArgs& args,
bool isConstructor) {
RootedObject proto(cx);
if (isConstructor) {
if (!GetPrototypeFromBuiltinConstructor(cx, args, JSProto_Array, &proto)) {
return false;
}
} else {
// We're emulating |new Array(n)| with |std_Array(n)| in self-hosted JS,
// and the proto should be %ArrayPrototype% regardless of the callee.
proto = GlobalObject::getOrCreateArrayPrototype(cx, cx->global());
if (!proto) {
return false;
}
}
if (args.length() != 1 || !args[0].isNumber()) {
return ArrayFromCallArgs(cx, args, proto);
}
uint32_t length;
if (args[0].isInt32()) {
int32_t i = args[0].toInt32();
if (i < 0) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_BAD_ARRAY_LENGTH);
return false;
}
length = uint32_t(i);
} else {
double d = args[0].toDouble();
length = ToUint32(d);
if (d != double(length)) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_BAD_ARRAY_LENGTH);
return false;
}
}
ArrayObject* obj =
NewPartlyAllocatedArrayForCallingAllocationSite(cx, length, proto);
if (!obj) {
return false;
}
args.rval().setObject(*obj);
return true;
}
/* ES5 15.4.2 */
bool js::ArrayConstructor(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
return ArrayConstructorImpl(cx, args, /* isConstructor = */ true);
}
bool js::array_construct(JSContext* cx, unsigned argc, Value* vp) {
CallArgs args = CallArgsFromVp(argc, vp);
MOZ_ASSERT(!args.isConstructing());
MOZ_ASSERT(args.length() == 1);
MOZ_ASSERT(args[0].isNumber());
return ArrayConstructorImpl(cx, args, /* isConstructor = */ false);
}
ArrayObject* js::ArrayConstructorOneArg(JSContext* cx, HandleObjectGroup group,
int32_t lengthInt) {
// Ion can call this with a group from a different realm when calling
// another realm's Array constructor.
Maybe<AutoRealm> ar;
if (cx->realm() != group->realm()) {
MOZ_ASSERT(cx->compartment() == group->compartment());
ar.emplace(cx, group);
}
if (lengthInt < 0) {
JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr,
JSMSG_BAD_ARRAY_LENGTH);
return nullptr;
}
uint32_t length = uint32_t(lengthInt);
ArrayObject* res = NewPartlyAllocatedArrayTryUseGroup(cx, group, length);
MOZ_ASSERT_IF(res, res->realm() == group->realm());
return res;
}
static JSObject* CreateArrayPrototype(JSContext* cx, JSProtoKey key) {
MOZ_ASSERT(key == JSProto_Array);
RootedObject proto(
cx, GlobalObject::getOrCreateObjectPrototype(cx, cx->global()));
if (!proto) {
return nullptr;
}
RootedObjectGroup group(cx,
ObjectGroup::defaultNewGroup(cx, &ArrayObject::class_,
TaggedProto(proto)));
if (!group) {
return nullptr;
}
RootedShape shape(cx, EmptyShape::getInitialShape(cx, &ArrayObject::class_,
TaggedProto(proto),
gc::AllocKind::OBJECT0));
if (!shape) {
return nullptr;
}
AutoSetNewObjectMetadata metadata(cx);
RootedArrayObject arrayProto(
cx, ArrayObject::createArray(cx, gc::AllocKind::OBJECT4, gc::TenuredHeap,
shape, group, 0, metadata));
if (!arrayProto || !JSObject::setSingleton(cx, arrayProto) ||
!JSObject::setDelegate(cx, arrayProto) ||
!AddLengthProperty(cx, arrayProto)) {
return nullptr;
}
/*
* The default 'new' group of Array.prototype is required by type inference
* to have unknown properties, to simplify handling of e.g. heterogenous
* arrays in JSON and script literals and allows setDenseArrayElement to
* be used without updating the indexed type set for such default arrays.
*/
ObjectGroupRealm& realm = ObjectGroupRealm::getForNewObject(cx);
if (!JSObject::setNewGroupUnknown(cx, realm, &ArrayObject::class_,
arrayProto)) {
return nullptr;
}
return arrayProto;
}
static bool array_proto_finish(JSContext* cx, JS::HandleObject ctor,
JS::HandleObject proto) {
// Add Array.prototype[@@unscopables]. ECMA-262 draft (2016 Mar 19) 22.1.3.32.
RootedObject unscopables(
cx, NewObjectWithGivenProto<PlainObject>(cx, nullptr, SingletonObject));
if (!unscopables) {
return false;
}
RootedValue value(cx, BooleanValue(true));
if (!DefineDataProperty(cx, unscopables, cx->names().copyWithin, value) ||
!DefineDataProperty(cx, unscopables, cx->names().entries, value) ||
!DefineDataProperty(cx, unscopables, cx->names().fill, value) ||
!DefineDataProperty(cx, unscopables, cx->names().find, value) ||
!DefineDataProperty(cx, unscopables, cx->names().findIndex, value) ||
!DefineDataProperty(cx, unscopables, cx->names().flat, value) ||
!DefineDataProperty(cx, unscopables, cx->names().flatMap, value) ||
!DefineDataProperty(cx, unscopables, cx->names().includes, value) ||
!DefineDataProperty(cx, unscopables, cx->names().keys, value) ||
!DefineDataProperty(cx, unscopables, cx->names().values, value)) {
return false;