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/* -*- 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 "vm/ArgumentsObject-inl.h"
#include "mozilla/PodOperations.h"
#include <algorithm>
#include "gc/FreeOp.h"
#include "jit/CalleeToken.h"
#include "jit/JitFrames.h"
#include "util/BitArray.h"
#include "vm/AsyncFunction.h"
#include "vm/GlobalObject.h"
#include "vm/Stack.h"
#include "vm/WellKnownAtom.h" // js_*_str
#include "gc/Nursery-inl.h"
#include "vm/FrameIter-inl.h" // js::FrameIter::unaliasedForEachActual
#include "vm/JSObject-inl.h"
#include "vm/NativeObject-inl.h"
#include "vm/Stack-inl.h"
using namespace js;
/* static */
size_t RareArgumentsData::bytesRequired(size_t numActuals) {
size_t extraBytes = NumWordsForBitArrayOfLength(numActuals) * sizeof(size_t);
return offsetof(RareArgumentsData, deletedBits_) + extraBytes;
}
/* static */
RareArgumentsData* RareArgumentsData::create(JSContext* cx,
ArgumentsObject* obj) {
size_t bytes = RareArgumentsData::bytesRequired(obj->initialLength());
uint8_t* data = AllocateObjectBuffer<uint8_t>(cx, obj, bytes);
if (!data) {
return nullptr;
}
mozilla::PodZero(data, bytes);
AddCellMemory(obj, bytes, MemoryUse::RareArgumentsData);
return new (data) RareArgumentsData();
}
bool ArgumentsObject::createRareData(JSContext* cx) {
MOZ_ASSERT(!data()->rareData);
RareArgumentsData* rareData = RareArgumentsData::create(cx, this);
if (!rareData) {
return false;
}
data()->rareData = rareData;
markElementOverridden();
return true;
}
bool ArgumentsObject::markElementDeleted(JSContext* cx, uint32_t i) {
RareArgumentsData* data = getOrCreateRareData(cx);
if (!data) {
return false;
}
data->markElementDeleted(initialLength(), i);
return true;
}
static void CopyStackFrameArguments(const AbstractFramePtr frame,
GCPtrValue* dst, unsigned totalArgs) {
MOZ_ASSERT_IF(frame.isInterpreterFrame(),
!frame.asInterpreterFrame()->runningInJit());
MOZ_ASSERT(std::max(frame.numActualArgs(), frame.numFormalArgs()) ==
totalArgs);
/* Copy arguments. */
Value* src = frame.argv();
Value* end = src + totalArgs;
while (src != end) {
(dst++)->init(*src++);
}
}
/* static */
void ArgumentsObject::MaybeForwardToCallObject(AbstractFramePtr frame,
ArgumentsObject* obj,
ArgumentsData* data) {
JSScript* script = frame.script();
if (frame.callee()->needsCallObject() && script->argumentsAliasesFormals()) {
obj->initFixedSlot(MAYBE_CALL_SLOT, ObjectValue(frame.callObj()));
for (PositionalFormalParameterIter fi(script); fi; fi++) {
if (fi.closedOver()) {
data->args[fi.argumentSlot()] = MagicEnvSlotValue(fi.location().slot());
obj->markArgumentForwarded();
}
}
}
}
/* static */
void ArgumentsObject::MaybeForwardToCallObject(JSFunction* callee,
JSObject* callObj,
ArgumentsObject* obj,
ArgumentsData* data) {
JSScript* script = callee->nonLazyScript();
if (callee->needsCallObject() && script->argumentsAliasesFormals()) {
MOZ_ASSERT(callObj && callObj->is<CallObject>());
obj->initFixedSlot(MAYBE_CALL_SLOT, ObjectValue(*callObj));
for (PositionalFormalParameterIter fi(script); fi; fi++) {
if (fi.closedOver()) {
data->args[fi.argumentSlot()] = MagicEnvSlotValue(fi.location().slot());
obj->markArgumentForwarded();
}
}
}
}
struct CopyFrameArgs {
AbstractFramePtr frame_;
explicit CopyFrameArgs(AbstractFramePtr frame) : frame_(frame) {}
void copyArgs(JSContext*, GCPtrValue* dst, unsigned totalArgs) const {
CopyStackFrameArguments(frame_, dst, totalArgs);
}
/*
* If a call object exists and the arguments object aliases formals, the
* call object is the canonical location for formals.
*/
void maybeForwardToCallObject(ArgumentsObject* obj, ArgumentsData* data) {
ArgumentsObject::MaybeForwardToCallObject(frame_, obj, data);
}
};
struct CopyJitFrameArgs {
jit::JitFrameLayout* frame_;
HandleObject callObj_;
CopyJitFrameArgs(jit::JitFrameLayout* frame, HandleObject callObj)
: frame_(frame), callObj_(callObj) {}
void copyArgs(JSContext*, GCPtrValue* dstBase, unsigned totalArgs) const {
unsigned numActuals = frame_->numActualArgs();
unsigned numFormals =
jit::CalleeTokenToFunction(frame_->calleeToken())->nargs();
MOZ_ASSERT(numActuals <= totalArgs);
MOZ_ASSERT(numFormals <= totalArgs);
MOZ_ASSERT(std::max(numActuals, numFormals) == totalArgs);
/* Copy all arguments. */
Value* src = frame_->argv() + 1; /* +1 to skip this. */
Value* end = src + numActuals;
GCPtrValue* dst = dstBase;
while (src != end) {
(dst++)->init(*src++);
}
if (numActuals < numFormals) {
GCPtrValue* dstEnd = dstBase + totalArgs;
while (dst != dstEnd) {
(dst++)->init(UndefinedValue());
}
}
}
/*
* If a call object exists and the arguments object aliases formals, the
* call object is the canonical location for formals.
*/
void maybeForwardToCallObject(ArgumentsObject* obj, ArgumentsData* data) {
JSFunction* callee = jit::CalleeTokenToFunction(frame_->calleeToken());
ArgumentsObject::MaybeForwardToCallObject(callee, callObj_, obj, data);
}
};
struct CopyScriptFrameIterArgs {
ScriptFrameIter& iter_;
explicit CopyScriptFrameIterArgs(ScriptFrameIter& iter) : iter_(iter) {}
void copyArgs(JSContext* cx, GCPtrValue* dstBase, unsigned totalArgs) const {
/* Copy actual arguments. */
iter_.unaliasedForEachActual(cx, CopyToHeap(dstBase));
/* Define formals which are not part of the actuals. */
unsigned numActuals = iter_.numActualArgs();
unsigned numFormals = iter_.calleeTemplate()->nargs();
MOZ_ASSERT(numActuals <= totalArgs);
MOZ_ASSERT(numFormals <= totalArgs);
MOZ_ASSERT(std::max(numActuals, numFormals) == totalArgs);
if (numActuals < numFormals) {
GCPtrValue* dst = dstBase + numActuals;
GCPtrValue* dstEnd = dstBase + totalArgs;
while (dst != dstEnd) {
(dst++)->init(UndefinedValue());
}
}
}
/*
* Ion frames are copying every argument onto the stack, other locations are
* invalid.
*/
void maybeForwardToCallObject(ArgumentsObject* obj, ArgumentsData* data) {
if (!iter_.isIon()) {
ArgumentsObject::MaybeForwardToCallObject(iter_.abstractFramePtr(), obj,
data);
}
}
};
struct CopyInlinedArgs {
HandleValueArray args_;
HandleObject callObj_;
HandleFunction callee_;
uint32_t numActuals_;
CopyInlinedArgs(HandleValueArray args, HandleObject callObj,
HandleFunction callee, uint32_t numActuals)
: args_(args),
callObj_(callObj),
callee_(callee),
numActuals_(numActuals) {}
void copyArgs(JSContext*, GCPtrValue* dstBase, unsigned totalArgs) const {
uint32_t numFormals = callee_->nargs();
MOZ_ASSERT(std::max(numActuals_, numFormals) == totalArgs);
// Copy actual arguments.
GCPtrValue* dst = dstBase;
for (uint32_t i = 0; i < numActuals_; i++) {
(dst++)->init(args_[i]);
}
// Fill in missing arguments with |undefined|.
if (numActuals_ < numFormals) {
GCPtrValue* dstEnd = dstBase + totalArgs;
while (dst != dstEnd) {
(dst++)->init(UndefinedValue());
}
}
}
/*
* If a call object exists and the arguments object aliases formals, the
* call object is the canonical location for formals.
*/
void maybeForwardToCallObject(ArgumentsObject* obj, ArgumentsData* data) {
ArgumentsObject::MaybeForwardToCallObject(callee_, callObj_, obj, data);
}
};
ArgumentsObject* ArgumentsObject::createTemplateObject(JSContext* cx,
bool mapped) {
const JSClass* clasp = mapped ? &MappedArgumentsObject::class_
: &UnmappedArgumentsObject::class_;
RootedObject proto(
cx, GlobalObject::getOrCreateObjectPrototype(cx, cx->global()));
if (!proto) {
return nullptr;
}
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, clasp, TaggedProto(proto.get())));
if (!group) {
return nullptr;
}
constexpr ObjectFlags objectFlags = {ObjectFlag::Indexed};
RootedShape shape(cx,
EmptyShape::getInitialShape(cx, clasp, TaggedProto(proto),
FINALIZE_KIND, objectFlags));
if (!shape) {
return nullptr;
}
AutoSetNewObjectMetadata metadata(cx);
JSObject* base;
JS_TRY_VAR_OR_RETURN_NULL(
cx, base,
NativeObject::create(cx, FINALIZE_KIND, gc::TenuredHeap, shape, group));
ArgumentsObject* obj = &base->as<js::ArgumentsObject>();
obj->initFixedSlot(ArgumentsObject::DATA_SLOT, PrivateValue(nullptr));
return obj;
}
ArgumentsObject* Realm::maybeArgumentsTemplateObject(bool mapped) const {
return mapped ? mappedArgumentsTemplate_ : unmappedArgumentsTemplate_;
}
ArgumentsObject* Realm::getOrCreateArgumentsTemplateObject(JSContext* cx,
bool mapped) {
WeakHeapPtr<ArgumentsObject*>& obj =
mapped ? mappedArgumentsTemplate_ : unmappedArgumentsTemplate_;
ArgumentsObject* templateObj = obj;
if (templateObj) {
return templateObj;
}
templateObj = ArgumentsObject::createTemplateObject(cx, mapped);
if (!templateObj) {
return nullptr;
}
obj.set(templateObj);
return templateObj;
}
template <typename CopyArgs>
/* static */
ArgumentsObject* ArgumentsObject::create(JSContext* cx, HandleFunction callee,
unsigned numActuals, CopyArgs& copy) {
bool mapped = callee->baseScript()->hasMappedArgsObj();
ArgumentsObject* templateObj =
cx->realm()->getOrCreateArgumentsTemplateObject(cx, mapped);
if (!templateObj) {
return nullptr;
}
RootedShape shape(cx, templateObj->lastProperty());
RootedObjectGroup group(cx, templateObj->group());
unsigned numFormals = callee->nargs();
unsigned numArgs = std::max(numActuals, numFormals);
unsigned numBytes = ArgumentsData::bytesRequired(numArgs);
Rooted<ArgumentsObject*> obj(cx);
ArgumentsData* data = nullptr;
{
// The copyArgs call below can allocate objects, so add this block scope
// to make sure we set the metadata for this arguments object first.
AutoSetNewObjectMetadata metadata(cx);
JSObject* base;
JS_TRY_VAR_OR_RETURN_NULL(
cx, base,
NativeObject::create(cx, FINALIZE_KIND, gc::DefaultHeap, shape, group));
obj = &base->as<ArgumentsObject>();
data = reinterpret_cast<ArgumentsData*>(
AllocateObjectBuffer<uint8_t>(cx, obj, numBytes));
if (!data) {
// Make the object safe for GC.
obj->initFixedSlot(DATA_SLOT, PrivateValue(nullptr));
return nullptr;
}
data->numArgs = numArgs;
data->rareData = nullptr;
// Initialize |args| with a pattern that is safe for GC tracing.
for (unsigned i = 0; i < numArgs; i++) {
data->args[i].init(UndefinedValue());
}
InitReservedSlot(obj, DATA_SLOT, data, numBytes, MemoryUse::ArgumentsData);
obj->initFixedSlot(CALLEE_SLOT, ObjectValue(*callee));
}
MOZ_ASSERT(data != nullptr);
/* Copy [0, numArgs) into data->slots. */
copy.copyArgs(cx, data->args, numArgs);
obj->initFixedSlot(INITIAL_LENGTH_SLOT,
Int32Value(numActuals << PACKED_BITS_COUNT));
copy.maybeForwardToCallObject(obj, data);
MOZ_ASSERT(obj->initialLength() == numActuals);
MOZ_ASSERT(!obj->hasOverriddenLength());
return obj;
}
ArgumentsObject* ArgumentsObject::createExpected(JSContext* cx,
AbstractFramePtr frame) {
MOZ_ASSERT(frame.script()->needsArgsObj());
RootedFunction callee(cx, frame.callee());
CopyFrameArgs copy(frame);
ArgumentsObject* argsobj = create(cx, callee, frame.numActualArgs(), copy);
if (!argsobj) {
return nullptr;
}
frame.initArgsObj(*argsobj);
return argsobj;
}
ArgumentsObject* ArgumentsObject::createUnexpected(JSContext* cx,
ScriptFrameIter& iter) {
RootedFunction callee(cx, iter.callee(cx));
CopyScriptFrameIterArgs copy(iter);
return create(cx, callee, iter.numActualArgs(), copy);
}
ArgumentsObject* ArgumentsObject::createUnexpected(JSContext* cx,
AbstractFramePtr frame) {
RootedFunction callee(cx, frame.callee());
CopyFrameArgs copy(frame);
return create(cx, callee, frame.numActualArgs(), copy);
}
ArgumentsObject* ArgumentsObject::createForIon(JSContext* cx,
jit::JitFrameLayout* frame,
HandleObject scopeChain) {
jit::CalleeToken token = frame->calleeToken();
MOZ_ASSERT(jit::CalleeTokenIsFunction(token));
RootedFunction callee(cx, jit::CalleeTokenToFunction(token));
RootedObject callObj(
cx, scopeChain->is<CallObject>() ? scopeChain.get() : nullptr);
CopyJitFrameArgs copy(frame, callObj);
return create(cx, callee, frame->numActualArgs(), copy);
}
/* static */
ArgumentsObject* ArgumentsObject::createFromValueArray(
JSContext* cx, HandleValueArray argsArray, HandleFunction callee,
HandleObject scopeChain, uint32_t numActuals) {
MOZ_ASSERT(numActuals <= MaxInlinedArgs);
RootedObject callObj(
cx, scopeChain->is<CallObject>() ? scopeChain.get() : nullptr);
CopyInlinedArgs copy(argsArray, callObj, callee, numActuals);
return create(cx, callee, numActuals, copy);
}
/* static */
ArgumentsObject* ArgumentsObject::createForInlinedIon(JSContext* cx,
Value* args,
HandleFunction callee,
HandleObject scopeChain,
uint32_t numActuals) {
RootedExternalValueArray rootedArgs(cx, numActuals, args);
HandleValueArray argsArray =
HandleValueArray::fromMarkedLocation(numActuals, args);
return createFromValueArray(cx, argsArray, callee, scopeChain, numActuals);
}
/* static */
ArgumentsObject* ArgumentsObject::finishForIonPure(JSContext* cx,
jit::JitFrameLayout* frame,
JSObject* scopeChain,
ArgumentsObject* obj) {
// JIT code calls this directly (no callVM), because it's faster, so we're
// not allowed to GC in here.
AutoUnsafeCallWithABI unsafe;
JSFunction* callee = jit::CalleeTokenToFunction(frame->calleeToken());
RootedObject callObj(cx, scopeChain->is<CallObject>() ? scopeChain : nullptr);
CopyJitFrameArgs copy(frame, callObj);
unsigned numActuals = frame->numActualArgs();
unsigned numFormals = callee->nargs();
unsigned numArgs = std::max(numActuals, numFormals);
unsigned numBytes = ArgumentsData::bytesRequired(numArgs);
ArgumentsData* data = reinterpret_cast<ArgumentsData*>(
AllocateObjectBuffer<uint8_t>(cx, obj, numBytes));
if (!data) {
// Make the object safe for GC. Don't report OOM, the slow path will
// retry the allocation.
cx->recoverFromOutOfMemory();
obj->initFixedSlot(DATA_SLOT, PrivateValue(nullptr));
return nullptr;
}
data->numArgs = numArgs;
data->rareData = nullptr;
obj->initFixedSlot(INITIAL_LENGTH_SLOT,
Int32Value(numActuals << PACKED_BITS_COUNT));
obj->initFixedSlot(DATA_SLOT, PrivateValue(data));
AddCellMemory(obj, numBytes, MemoryUse::ArgumentsData);
obj->initFixedSlot(MAYBE_CALL_SLOT, UndefinedValue());
obj->initFixedSlot(CALLEE_SLOT, ObjectValue(*callee));
copy.copyArgs(cx, data->args, numArgs);
if (callObj && callee->needsCallObject()) {
copy.maybeForwardToCallObject(obj, data);
}
MOZ_ASSERT(obj->initialLength() == numActuals);
MOZ_ASSERT(!obj->hasOverriddenLength());
return obj;
}
/* static */
bool ArgumentsObject::obj_delProperty(JSContext* cx, HandleObject obj,
HandleId id, ObjectOpResult& result) {
ArgumentsObject& argsobj = obj->as<ArgumentsObject>();
if (JSID_IS_INT(id)) {
unsigned arg = unsigned(JSID_TO_INT(id));
if (arg < argsobj.initialLength() && !argsobj.isElementDeleted(arg)) {
if (!argsobj.markElementDeleted(cx, arg)) {
return false;
}
}
} else if (JSID_IS_ATOM(id, cx->names().length)) {
argsobj.markLengthOverridden();
} else if (JSID_IS_ATOM(id, cx->names().callee)) {
argsobj.as<MappedArgumentsObject>().markCalleeOverridden();
} else if (JSID_IS_SYMBOL(id) &&
JSID_TO_SYMBOL(id) == cx->wellKnownSymbols().iterator) {
argsobj.markIteratorOverridden();
}
return result.succeed();
}
/* static */
bool ArgumentsObject::obj_mayResolve(const JSAtomState& names, jsid id,
JSObject*) {
// Arguments might resolve indexes, Symbol.iterator, or length/callee.
if (JSID_IS_ATOM(id)) {
JSAtom* atom = JSID_TO_ATOM(id);
uint32_t index;
if (atom->isIndex(&index)) {
return true;
}
return atom == names.length || atom == names.callee;
}
return id.isInt() || id.isWellKnownSymbol(JS::SymbolCode::iterator);
}
static bool MappedArgGetter(JSContext* cx, HandleObject obj, HandleId id,
MutableHandleValue vp) {
MappedArgumentsObject& argsobj = obj->as<MappedArgumentsObject>();
if (JSID_IS_INT(id)) {
/*
* arg can exceed the number of arguments if a script changed the
* prototype to point to another Arguments object with a bigger argc.
*/
unsigned arg = unsigned(JSID_TO_INT(id));
if (arg < argsobj.initialLength() && !argsobj.isElementDeleted(arg)) {
vp.set(argsobj.element(arg));
}
} else if (JSID_IS_ATOM(id, cx->names().length)) {
if (!argsobj.hasOverriddenLength()) {
vp.setInt32(argsobj.initialLength());
}
} else {
MOZ_ASSERT(JSID_IS_ATOM(id, cx->names().callee));
if (!argsobj.hasOverriddenCallee()) {
vp.setObject(argsobj.callee());
}
}
return true;
}
static bool MappedArgSetter(JSContext* cx, HandleObject obj, HandleId id,
HandleValue v, ObjectOpResult& result) {
if (!obj->is<MappedArgumentsObject>()) {
return result.succeed();
}
Handle<MappedArgumentsObject*> argsobj = obj.as<MappedArgumentsObject>();
Rooted<PropertyDescriptor> desc(cx);
if (!GetOwnPropertyDescriptor(cx, argsobj, id, &desc)) {
return false;
}
MOZ_ASSERT(desc.object());
unsigned attrs = desc.attributes();
MOZ_ASSERT(!(attrs & JSPROP_READONLY));
attrs &= (JSPROP_ENUMERATE | JSPROP_PERMANENT); /* only valid attributes */
if (JSID_IS_INT(id)) {
unsigned arg = unsigned(JSID_TO_INT(id));
if (arg < argsobj->initialLength() && !argsobj->isElementDeleted(arg)) {
argsobj->setElement(arg, v);
return result.succeed();
}
} else {
MOZ_ASSERT(JSID_IS_ATOM(id, cx->names().length) ||
JSID_IS_ATOM(id, cx->names().callee));
}
/*
* For simplicity we use delete/define to replace the property with a
* simple data property. Note that we rely on ArgumentsObject::obj_delProperty
* to set the corresponding override-bit.
* Note also that we must define the property instead of setting it in case
* the user has changed the prototype to an object that has a setter for
* this id.
*/
ObjectOpResult ignored;
return NativeDeleteProperty(cx, argsobj, id, ignored) &&
NativeDefineDataProperty(cx, argsobj, id, v, attrs, result);
}
/* static */
bool ArgumentsObject::getArgumentsIterator(JSContext* cx,
MutableHandleValue val) {
HandlePropertyName shName = cx->names().ArrayValues;
RootedAtom name(cx, cx->names().values);
return GlobalObject::getSelfHostedFunction(cx, cx->global(), shName, name, 0,
val);
}
/* static */
bool ArgumentsObject::reifyLength(JSContext* cx, Handle<ArgumentsObject*> obj) {
if (obj->hasOverriddenLength()) {
return true;
}
RootedId id(cx, NameToId(cx->names().length));
RootedValue val(cx, Int32Value(obj->initialLength()));
if (!NativeDefineDataProperty(cx, obj, id, val, JSPROP_RESOLVING)) {
return false;
}
obj->markLengthOverridden();
return true;
}
/* static */
bool ArgumentsObject::reifyIterator(JSContext* cx,
Handle<ArgumentsObject*> obj) {
if (obj->hasOverriddenIterator()) {
return true;
}
RootedId iteratorId(cx, SYMBOL_TO_JSID(cx->wellKnownSymbols().iterator));
RootedValue val(cx);
if (!ArgumentsObject::getArgumentsIterator(cx, &val)) {
return false;
}
if (!NativeDefineDataProperty(cx, obj, iteratorId, val, JSPROP_RESOLVING)) {
return false;
}
obj->markIteratorOverridden();
return true;
}
/* static */
bool MappedArgumentsObject::obj_resolve(JSContext* cx, HandleObject obj,
HandleId id, bool* resolvedp) {
Rooted<MappedArgumentsObject*> argsobj(cx, &obj->as<MappedArgumentsObject>());
if (JSID_IS_SYMBOL(id) &&
JSID_TO_SYMBOL(id) == cx->wellKnownSymbols().iterator) {
if (argsobj->hasOverriddenIterator()) {
return true;
}
if (!reifyIterator(cx, argsobj)) {
return false;
}
*resolvedp = true;
return true;
}
unsigned attrs = JSPROP_RESOLVING;
if (JSID_IS_INT(id)) {
uint32_t arg = uint32_t(JSID_TO_INT(id));
if (arg >= argsobj->initialLength() || argsobj->isElementDeleted(arg)) {
return true;
}
attrs |= JSPROP_ENUMERATE;
} else if (JSID_IS_ATOM(id, cx->names().length)) {
if (argsobj->hasOverriddenLength()) {
return true;
}
} else {
if (!JSID_IS_ATOM(id, cx->names().callee)) {
return true;
}
if (argsobj->hasOverriddenCallee()) {
return true;
}
}
if (!NativeDefineAccessorProperty(cx, argsobj, id, MappedArgGetter,
MappedArgSetter, attrs)) {
return false;
}
*resolvedp = true;
return true;
}
/* static */
bool MappedArgumentsObject::obj_enumerate(JSContext* cx, HandleObject obj) {
Rooted<MappedArgumentsObject*> argsobj(cx, &obj->as<MappedArgumentsObject>());
RootedId id(cx);
bool found;
// Trigger reflection.
id = NameToId(cx->names().length);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
id = NameToId(cx->names().callee);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
id = SYMBOL_TO_JSID(cx->wellKnownSymbols().iterator);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
for (unsigned i = 0; i < argsobj->initialLength(); i++) {
id = INT_TO_JSID(i);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
}
return true;
}
// ES 2017 draft 9.4.4.2
/* static */
bool MappedArgumentsObject::obj_defineProperty(JSContext* cx, HandleObject obj,
HandleId id,
Handle<PropertyDescriptor> desc,
ObjectOpResult& result) {
// Step 1.
Rooted<MappedArgumentsObject*> argsobj(cx, &obj->as<MappedArgumentsObject>());
// Steps 2-3.
bool isMapped = false;
if (JSID_IS_INT(id)) {
unsigned arg = unsigned(JSID_TO_INT(id));
isMapped =
arg < argsobj->initialLength() && !argsobj->isElementDeleted(arg);
}
// Step 4.
Rooted<PropertyDescriptor> newArgDesc(cx, desc);
// Step 5.
if (!desc.isAccessorDescriptor() && isMapped) {
// Step 5.a.
if (desc.hasWritable() && !desc.writable()) {
if (!desc.hasValue()) {
RootedValue v(cx, argsobj->element(JSID_TO_INT(id)));
newArgDesc.setValue(v);
}
newArgDesc.setGetter(nullptr);
newArgDesc.setSetter(nullptr);
} else {
// In this case the live mapping is supposed to keep working,
// we have to pass along the Getter/Setter otherwise they are
// overwritten.
newArgDesc.setGetter(MappedArgGetter);
newArgDesc.setSetter(MappedArgSetter);
newArgDesc.value().setUndefined();
newArgDesc.attributesRef() |= JSPROP_IGNORE_VALUE;
}
}
// Step 6. NativeDefineProperty will lookup [[Value]] for us.
if (!NativeDefineProperty(cx, obj.as<NativeObject>(), id, newArgDesc,
result)) {
return false;
}
// Step 7.
if (!result.ok()) {
return true;
}
// Step 8.
if (isMapped) {
unsigned arg = unsigned(JSID_TO_INT(id));
if (desc.isAccessorDescriptor()) {
if (!argsobj->markElementDeleted(cx, arg)) {
return false;
}
} else {
if (desc.hasValue()) {
argsobj->setElement(arg, desc.value());
}
if (desc.hasWritable() && !desc.writable()) {
if (!argsobj->markElementDeleted(cx, arg)) {
return false;
}
}
}
}
// Step 9.
return result.succeed();
}
static bool UnmappedArgGetter(JSContext* cx, HandleObject obj, HandleId id,
MutableHandleValue vp) {
UnmappedArgumentsObject& argsobj = obj->as<UnmappedArgumentsObject>();
if (JSID_IS_INT(id)) {
/*
* arg can exceed the number of arguments if a script changed the
* prototype to point to another Arguments object with a bigger argc.
*/
unsigned arg = unsigned(JSID_TO_INT(id));
if (arg < argsobj.initialLength() && !argsobj.isElementDeleted(arg)) {
vp.set(argsobj.element(arg));
}
} else {
MOZ_ASSERT(JSID_IS_ATOM(id, cx->names().length));
if (!argsobj.hasOverriddenLength()) {
vp.setInt32(argsobj.initialLength());
}
}
return true;
}
static bool UnmappedArgSetter(JSContext* cx, HandleObject obj, HandleId id,
HandleValue v, ObjectOpResult& result) {
if (!obj->is<UnmappedArgumentsObject>()) {
return result.succeed();
}
Handle<UnmappedArgumentsObject*> argsobj = obj.as<UnmappedArgumentsObject>();
Rooted<PropertyDescriptor> desc(cx);
if (!GetOwnPropertyDescriptor(cx, argsobj, id, &desc)) {
return false;
}
MOZ_ASSERT(desc.object());
unsigned attrs = desc.attributes();
MOZ_ASSERT(!(attrs & JSPROP_READONLY));
attrs &= (JSPROP_ENUMERATE | JSPROP_PERMANENT); /* only valid attributes */
if (JSID_IS_INT(id)) {
unsigned arg = unsigned(JSID_TO_INT(id));
if (arg < argsobj->initialLength()) {
argsobj->setElement(arg, v);
return result.succeed();
}
} else {
MOZ_ASSERT(JSID_IS_ATOM(id, cx->names().length));
}
/*
* For simplicity we use delete/define to replace the property with a
* simple data property. Note that we rely on ArgumentsObject::obj_delProperty
* to set the corresponding override-bit.
*/
ObjectOpResult ignored;
return NativeDeleteProperty(cx, argsobj, id, ignored) &&
NativeDefineDataProperty(cx, argsobj, id, v, attrs, result);
}
/* static */
bool UnmappedArgumentsObject::obj_resolve(JSContext* cx, HandleObject obj,
HandleId id, bool* resolvedp) {
Rooted<UnmappedArgumentsObject*> argsobj(cx,
&obj->as<UnmappedArgumentsObject>());
if (JSID_IS_SYMBOL(id) &&
JSID_TO_SYMBOL(id) == cx->wellKnownSymbols().iterator) {
if (argsobj->hasOverriddenIterator()) {
return true;
}
if (!reifyIterator(cx, argsobj)) {
return false;
}
*resolvedp = true;
return true;
}
if (JSID_IS_ATOM(id, cx->names().callee)) {
RootedObject throwTypeError(
cx, GlobalObject::getOrCreateThrowTypeError(cx, cx->global()));
if (!throwTypeError) {
return false;
}
unsigned attrs =
JSPROP_RESOLVING | JSPROP_PERMANENT | JSPROP_GETTER | JSPROP_SETTER;
if (!NativeDefineAccessorProperty(cx, argsobj, id, throwTypeError,
throwTypeError, attrs)) {
return false;
}
*resolvedp = true;
return true;
}
unsigned attrs = JSPROP_RESOLVING;
if (JSID_IS_INT(id)) {
uint32_t arg = uint32_t(JSID_TO_INT(id));
if (arg >= argsobj->initialLength() || argsobj->isElementDeleted(arg)) {
return true;
}
attrs |= JSPROP_ENUMERATE;
} else if (JSID_IS_ATOM(id, cx->names().length)) {
if (argsobj->hasOverriddenLength()) {
return true;
}
} else {
return true;
}
if (!NativeDefineAccessorProperty(cx, argsobj, id, UnmappedArgGetter,
UnmappedArgSetter, attrs)) {
return false;
}
*resolvedp = true;
return true;
}
/* static */
bool UnmappedArgumentsObject::obj_enumerate(JSContext* cx, HandleObject obj) {
Rooted<UnmappedArgumentsObject*> argsobj(cx,
&obj->as<UnmappedArgumentsObject>());
RootedId id(cx);
bool found;
// Trigger reflection.
id = NameToId(cx->names().length);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
id = NameToId(cx->names().callee);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
id = SYMBOL_TO_JSID(cx->wellKnownSymbols().iterator);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
for (unsigned i = 0; i < argsobj->initialLength(); i++) {
id = INT_TO_JSID(i);
if (!HasOwnProperty(cx, argsobj, id, &found)) {
return false;
}
}
return true;
}
void ArgumentsObject::finalize(JSFreeOp* fop, JSObject* obj) {
MOZ_ASSERT(!IsInsideNursery(obj));
ArgumentsObject& argsobj = obj->as<ArgumentsObject>();
if (argsobj.data()) {
fop->free_(&argsobj, argsobj.maybeRareData(),
RareArgumentsData::bytesRequired(argsobj.initialLength()),
MemoryUse::RareArgumentsData);
fop->free_(&argsobj, argsobj.data(),
ArgumentsData::bytesRequired(argsobj.data()->numArgs),
MemoryUse::ArgumentsData);
}
}
void ArgumentsObject::trace(JSTracer* trc, JSObject* obj) {
ArgumentsObject& argsobj = obj->as<ArgumentsObject>();
if (ArgumentsData* data =
argsobj.data()) { // Template objects have no ArgumentsData.
TraceRange(trc, data->numArgs, data->begin(), js_arguments_str);
}
}
/* static */
size_t ArgumentsObject::objectMoved(JSObject* dst, JSObject* src) {
ArgumentsObject* ndst = &dst->as<ArgumentsObject>();
const ArgumentsObject* nsrc = &src->as<ArgumentsObject>();
MOZ_ASSERT(ndst->data() == nsrc->data());
if (!IsInsideNursery(src)) {
return 0;
}
Nursery& nursery = dst->runtimeFromMainThread()->gc.nursery();
size_t nbytesTotal = 0;
uint32_t nDataBytes = ArgumentsData::bytesRequired(nsrc->data()->numArgs);
if (!nursery.isInside(nsrc->data())) {
nursery.removeMallocedBufferDuringMinorGC(nsrc->data());
} else {
AutoEnterOOMUnsafeRegion oomUnsafe;
uint8_t* data = nsrc->zone()->pod_malloc<uint8_t>(nDataBytes);
if (!data) {
oomUnsafe.crash(
"Failed to allocate ArgumentsObject data while tenuring.");
}
ndst->initFixedSlot(DATA_SLOT, PrivateValue(data));
mozilla::PodCopy(data, reinterpret_cast<uint8_t*>(nsrc->data()),
nDataBytes);
nbytesTotal += nDataBytes;
}
AddCellMemory(ndst, nDataBytes, MemoryUse::ArgumentsData);
if (RareArgumentsData* srcRareData = nsrc->maybeRareData()) {
uint32_t nbytes = RareArgumentsData::bytesRequired(nsrc->initialLength());
if (!nursery.isInside(srcRareData)) {
nursery.removeMallocedBufferDuringMinorGC(srcRareData);
} else {
AutoEnterOOMUnsafeRegion oomUnsafe;
uint8_t* dstRareData = nsrc->zone()->pod_malloc<uint8_t>(nbytes);
if (!dstRareData) {
oomUnsafe.crash(
"Failed to allocate RareArgumentsData data while tenuring.");
}
ndst->data()->rareData = (RareArgumentsData*)dstRareData;
mozilla::PodCopy(dstRareData, reinterpret_cast<uint8_t*>(srcRareData),
nbytes);
nbytesTotal += nbytes;
}
AddCellMemory(ndst, nbytes, MemoryUse::RareArgumentsData);
}
return nbytesTotal;
}
/*
* The classes below collaborate to lazily reflect and synchronize actual
* argument values, argument count, and callee function object stored in a
* stack frame with their corresponding property values in the frame's
* arguments object.
*/
const JSClassOps MappedArgumentsObject::classOps_ = {
nullptr, // addProperty
ArgumentsObject::obj_delProperty, // delProperty
MappedArgumentsObject::obj_enumerate, // enumerate
nullptr, // newEnumerate
MappedArgumentsObject::obj_resolve, // resolve
ArgumentsObject::obj_mayResolve, // mayResolve
ArgumentsObject::finalize, // finalize
nullptr, // call
nullptr, // hasInstance
nullptr, // construct
ArgumentsObject::trace, // trace
};
const js::ClassExtension MappedArgumentsObject::classExt_ = {
ArgumentsObject::objectMoved, // objectMovedOp
};
const ObjectOps MappedArgumentsObject::objectOps_ = {
nullptr, // lookupProperty
MappedArgumentsObject::obj_defineProperty, // defineProperty
nullptr, // hasProperty
nullptr, // getProperty
nullptr, // setProperty
nullptr, // getOwnPropertyDescriptor
nullptr, // deleteProperty
nullptr, // getElements
nullptr, // funToString
};
const JSClass MappedArgumentsObject::class_ = {
"Arguments",
JSCLASS_DELAY_METADATA_BUILDER |
JSCLASS_HAS_RESERVED_SLOTS(MappedArgumentsObject::RESERVED_SLOTS) |
JSCLASS_HAS_CACHED_PROTO(JSProto_Object) |
JSCLASS_SKIP_NURSERY_FINALIZE | JSCLASS_BACKGROUND_FINALIZE,
&MappedArgumentsObject::classOps_,
nullptr,
&MappedArgumentsObject::classExt_,
&MappedArgumentsObject::objectOps_};
/*
* Unmapped arguments is significantly less magical than mapped arguments, so
* it is represented by a different class while sharing some functionality.
*/
const JSClassOps UnmappedArgumentsObject::classOps_ = {
nullptr, // addProperty
ArgumentsObject::obj_delProperty, // delProperty
UnmappedArgumentsObject::obj_enumerate, // enumerate
nullptr, // newEnumerate
UnmappedArgumentsObject::obj_resolve, // resolve
ArgumentsObject::obj_mayResolve, // mayResolve
ArgumentsObject::finalize, // finalize
nullptr, // call
nullptr, // hasInstance
nullptr, // construct
ArgumentsObject::trace, // trace
};
const js::ClassExtension UnmappedArgumentsObject::classExt_ = {
ArgumentsObject::objectMoved, // objectMovedOp
};
const JSClass UnmappedArgumentsObject::class_ = {
"Arguments",
JSCLASS_DELAY_METADATA_BUILDER |
JSCLASS_HAS_RESERVED_SLOTS(UnmappedArgumentsObject::RESERVED_SLOTS) |
JSCLASS_HAS_CACHED_PROTO(JSProto_Object) |
JSCLASS_SKIP_NURSERY_FINALIZE | JSCLASS_BACKGROUND_FINALIZE,
&UnmappedArgumentsObject::classOps_, nullptr,
&UnmappedArgumentsObject::classExt_};