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EnvironmentObject.cpp
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EnvironmentObject.cpp
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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/EnvironmentObject-inl.h"
#include "builtin/ModuleObject.h"
#include "gc/Policy.h"
#include "vm/ArgumentsObject.h"
#include "vm/AsyncFunction.h"
#include "vm/GlobalObject.h"
#include "vm/Iteration.h"
#include "vm/ProxyObject.h"
#include "vm/Realm.h"
#include "vm/Shape.h"
#include "vm/Xdr.h"
#include "wasm/WasmInstance.h"
#include "gc/Marking-inl.h"
#include "vm/JSAtom-inl.h"
#include "vm/JSScript-inl.h"
#include "vm/NativeObject-inl.h"
#include "vm/Stack-inl.h"
#include "vm/TypeInference-inl.h"
using namespace js;
typedef Rooted<ArgumentsObject*> RootedArgumentsObject;
typedef MutableHandle<ArgumentsObject*> MutableHandleArgumentsObject;
/*****************************************************************************/
Shape* js::EnvironmentCoordinateToEnvironmentShape(JSScript* script,
jsbytecode* pc) {
MOZ_ASSERT(JOF_OPTYPE(JSOp(*pc)) == JOF_ENVCOORD);
ScopeIter si(script->innermostScope(pc));
uint32_t hops = EnvironmentCoordinate(pc).hops();
while (true) {
MOZ_ASSERT(!si.done());
if (si.hasSyntacticEnvironment()) {
if (!hops) {
break;
}
hops--;
}
si++;
}
return si.environmentShape();
}
static const uint32_t ENV_COORDINATE_NAME_THRESHOLD = 20;
void EnvironmentCoordinateNameCache::purge() {
shape = nullptr;
map.clearAndCompact();
}
PropertyName* js::EnvironmentCoordinateName(
EnvironmentCoordinateNameCache& cache, JSScript* script, jsbytecode* pc) {
Shape* shape = EnvironmentCoordinateToEnvironmentShape(script, pc);
if (shape != cache.shape && shape->slot() >= ENV_COORDINATE_NAME_THRESHOLD) {
cache.purge();
if (cache.map.reserve(shape->slot())) {
cache.shape = shape;
Shape::Range<NoGC> r(shape);
while (!r.empty()) {
cache.map.putNewInfallible(r.front().slot(), r.front().propid());
r.popFront();
}
}
}
jsid id;
EnvironmentCoordinate ec(pc);
if (shape == cache.shape) {
EnvironmentCoordinateNameCache::Map::Ptr p = cache.map.lookup(ec.slot());
id = p->value();
} else {
Shape::Range<NoGC> r(shape);
while (r.front().slot() != ec.slot()) {
r.popFront();
}
id = r.front().propidRaw();
}
/* Beware nameless destructuring formal. */
if (!JSID_IS_ATOM(id)) {
return script->runtimeFromAnyThread()->commonNames->empty;
}
return JSID_TO_ATOM(id)->asPropertyName();
}
JSScript* js::EnvironmentCoordinateFunctionScript(JSScript* script,
jsbytecode* pc) {
MOZ_ASSERT(JOF_OPTYPE(JSOp(*pc)) == JOF_ENVCOORD);
ScopeIter si(script->innermostScope(pc));
uint32_t hops = EnvironmentCoordinate(pc).hops();
while (true) {
if (si.hasSyntacticEnvironment()) {
if (!hops) {
break;
}
hops--;
}
si++;
}
if (si.kind() != ScopeKind::Function) {
return nullptr;
}
return si.scope()->as<FunctionScope>().script();
}
/*****************************************************************************/
CallObject* CallObject::create(JSContext* cx, HandleShape shape,
HandleObjectGroup group) {
MOZ_ASSERT(!group->singleton(),
"passed a singleton group to create() (use createSingleton() "
"instead)");
gc::AllocKind kind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(CanBeFinalizedInBackground(kind, &CallObject::class_));
kind = gc::GetBackgroundAllocKind(kind);
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(
cx, obj, NativeObject::create(cx, kind, gc::DefaultHeap, shape, group));
return &obj->as<CallObject>();
}
CallObject* CallObject::createSingleton(JSContext* cx, HandleShape shape) {
gc::AllocKind kind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(CanBeFinalizedInBackground(kind, &CallObject::class_));
kind = gc::GetBackgroundAllocKind(kind);
RootedObjectGroup group(
cx, ObjectGroup::lazySingletonGroup(cx, /* oldGroup = */ nullptr, &class_,
TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(
cx, obj, NativeObject::create(cx, kind, gc::TenuredHeap, shape, group));
MOZ_ASSERT(obj->isSingleton(),
"group created inline above must be a singleton");
return &obj->as<CallObject>();
}
/*
* Create a CallObject for a JSScript that is not initialized to any particular
* callsite. This object can either be initialized (with an enclosing scope and
* callee) or used as a template for jit compilation.
*/
CallObject* CallObject::createTemplateObject(JSContext* cx, HandleScript script,
HandleObject enclosing,
gc::InitialHeap heap) {
Rooted<FunctionScope*> scope(cx, &script->bodyScope()->as<FunctionScope>());
RootedShape shape(cx, scope->environmentShape());
MOZ_ASSERT(shape->getObjectClass() == &class_);
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, &class_, TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
gc::AllocKind kind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(CanBeFinalizedInBackground(kind, &class_));
kind = gc::GetBackgroundAllocKind(kind);
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(cx, obj,
NativeObject::create(cx, kind, heap, shape, group));
CallObject* callObj = &obj->as<CallObject>();
callObj->initEnclosingEnvironment(enclosing);
if (scope->hasParameterExprs()) {
// If there are parameter expressions, all parameters are lexical and
// have TDZ.
for (BindingIter bi(script->bodyScope()); bi; bi++) {
BindingLocation loc = bi.location();
if (loc.kind() == BindingLocation::Kind::Environment &&
BindingKindIsLexical(bi.kind())) {
callObj->initSlot(loc.slot(), MagicValue(JS_UNINITIALIZED_LEXICAL));
}
}
}
return callObj;
}
/*
* Construct a call object for the given bindings. If this is a call object
* for a function invocation, callee should be the function being called.
* Otherwise it must be a call object for eval of strict mode code, and callee
* must be null.
*/
CallObject* CallObject::create(JSContext* cx, HandleFunction callee,
HandleObject enclosing) {
RootedScript script(cx, callee->nonLazyScript());
gc::InitialHeap heap =
script->treatAsRunOnce() ? gc::TenuredHeap : gc::DefaultHeap;
CallObject* callobj =
CallObject::createTemplateObject(cx, script, enclosing, heap);
if (!callobj) {
return nullptr;
}
callobj->initFixedSlot(CALLEE_SLOT, ObjectValue(*callee));
if (script->treatAsRunOnce()) {
Rooted<CallObject*> ncallobj(cx, callobj);
if (!JSObject::setSingleton(cx, ncallobj)) {
return nullptr;
}
return ncallobj;
}
return callobj;
}
CallObject* CallObject::create(JSContext* cx, AbstractFramePtr frame) {
MOZ_ASSERT(frame.isFunctionFrame());
cx->check(frame);
RootedObject envChain(cx, frame.environmentChain());
RootedFunction callee(cx, frame.callee());
CallObject* callobj = create(cx, callee, envChain);
if (!callobj) {
return nullptr;
}
if (!frame.script()->bodyScope()->as<FunctionScope>().hasParameterExprs()) {
// If there are no defaults, copy the aliased arguments into the call
// object manually. If there are defaults, bytecode is generated to do
// the copying.
for (PositionalFormalParameterIter fi(frame.script()); fi; fi++) {
if (!fi.closedOver()) {
continue;
}
callobj->setAliasedBinding(
cx, fi,
frame.unaliasedFormal(fi.argumentSlot(), DONT_CHECK_ALIASING));
}
}
return callobj;
}
CallObject* CallObject::createHollowForDebug(JSContext* cx,
HandleFunction callee) {
MOZ_ASSERT(!callee->needsCallObject());
RootedScript script(cx, callee->nonLazyScript());
Rooted<FunctionScope*> scope(cx, &script->bodyScope()->as<FunctionScope>());
RootedShape shape(cx, FunctionScope::getEmptyEnvironmentShape(
cx, scope->hasParameterExprs()));
if (!shape) {
return nullptr;
}
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, &class_, TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
Rooted<CallObject*> callobj(cx, create(cx, shape, group));
if (!callobj) {
return nullptr;
}
// This environment's enclosing link is never used: the
// DebugEnvironmentProxy that refers to this scope carries its own
// enclosing link, which is what Debugger uses to construct the tree of
// Debugger.Environment objects.
callobj->initEnclosingEnvironment(&cx->global()->lexicalEnvironment());
callobj->initFixedSlot(CALLEE_SLOT, ObjectValue(*callee));
RootedValue optimizedOut(cx, MagicValue(JS_OPTIMIZED_OUT));
RootedId id(cx);
for (Rooted<BindingIter> bi(cx, BindingIter(script)); bi; bi++) {
id = NameToId(bi.name()->asPropertyName());
if (!SetProperty(cx, callobj, id, optimizedOut)) {
return nullptr;
}
}
return callobj;
}
const Class CallObject::class_ = {
"Call", JSCLASS_IS_ANONYMOUS |
JSCLASS_HAS_RESERVED_SLOTS(CallObject::RESERVED_SLOTS)};
/*****************************************************************************/
/* static */ VarEnvironmentObject* VarEnvironmentObject::create(
JSContext* cx, HandleShape shape, HandleObject enclosing,
gc::InitialHeap heap) {
MOZ_ASSERT(shape->getObjectClass() == &class_);
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, &class_, TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
gc::AllocKind kind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(CanBeFinalizedInBackground(kind, &class_));
kind = gc::GetBackgroundAllocKind(kind);
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(cx, obj,
NativeObject::create(cx, kind, heap, shape, group));
VarEnvironmentObject* env = &obj->as<VarEnvironmentObject>();
MOZ_ASSERT(!env->inDictionaryMode());
MOZ_ASSERT(env->isDelegate());
env->initEnclosingEnvironment(enclosing);
return env;
}
/* static */ VarEnvironmentObject* VarEnvironmentObject::create(
JSContext* cx, HandleScope scope, AbstractFramePtr frame) {
#ifdef DEBUG
if (frame.isEvalFrame()) {
MOZ_ASSERT(scope->is<EvalScope>() && scope == frame.script()->bodyScope());
MOZ_ASSERT_IF(frame.isInterpreterFrame(),
cx->interpreterFrame() == frame.asInterpreterFrame());
MOZ_ASSERT_IF(frame.isInterpreterFrame(),
cx->interpreterRegs().pc == frame.script()->code());
} else {
MOZ_ASSERT(frame.environmentChain());
MOZ_ASSERT_IF(
frame.callee()->needsCallObject(),
&frame.environmentChain()->as<CallObject>().callee() == frame.callee());
}
#endif
RootedScript script(cx, frame.script());
RootedObject envChain(cx, frame.environmentChain());
gc::InitialHeap heap =
script->treatAsRunOnce() ? gc::TenuredHeap : gc::DefaultHeap;
RootedShape shape(cx, scope->environmentShape());
VarEnvironmentObject* env = create(cx, shape, envChain, heap);
if (!env) {
return nullptr;
}
env->initScope(scope);
return env;
}
/* static */ VarEnvironmentObject* VarEnvironmentObject::createHollowForDebug(
JSContext* cx, Handle<VarScope*> scope) {
MOZ_ASSERT(!scope->hasEnvironment());
RootedShape shape(cx, VarScope::getEmptyEnvironmentShape(cx));
if (!shape) {
return nullptr;
}
// This environment's enclosing link is never used: the
// DebugEnvironmentProxy that refers to this scope carries its own
// enclosing link, which is what Debugger uses to construct the tree of
// Debugger.Environment objects.
RootedObject enclosingEnv(cx, &cx->global()->lexicalEnvironment());
Rooted<VarEnvironmentObject*> env(
cx, create(cx, shape, enclosingEnv, gc::TenuredHeap));
if (!env) {
return nullptr;
}
RootedValue optimizedOut(cx, MagicValue(JS_OPTIMIZED_OUT));
RootedId id(cx);
for (Rooted<BindingIter> bi(cx, BindingIter(scope)); bi; bi++) {
id = NameToId(bi.name()->asPropertyName());
if (!SetProperty(cx, env, id, optimizedOut)) {
return nullptr;
}
}
env->initScope(scope);
return env;
}
const Class VarEnvironmentObject::class_ = {
"Var", JSCLASS_IS_ANONYMOUS | JSCLASS_HAS_RESERVED_SLOTS(
VarEnvironmentObject::RESERVED_SLOTS)};
/*****************************************************************************/
const ObjectOps ModuleEnvironmentObject::objectOps_ = {
ModuleEnvironmentObject::lookupProperty,
nullptr, /* defineProperty */
ModuleEnvironmentObject::hasProperty,
ModuleEnvironmentObject::getProperty,
ModuleEnvironmentObject::setProperty,
ModuleEnvironmentObject::getOwnPropertyDescriptor,
ModuleEnvironmentObject::deleteProperty,
nullptr, /* getElements */
nullptr};
const ClassOps ModuleEnvironmentObject::classOps_ = {
nullptr, /* addProperty */
nullptr, /* delProperty */
nullptr, /* enumerate */
ModuleEnvironmentObject::newEnumerate};
const Class ModuleEnvironmentObject::class_ = {
"ModuleEnvironmentObject",
JSCLASS_HAS_RESERVED_SLOTS(ModuleEnvironmentObject::RESERVED_SLOTS) |
JSCLASS_IS_ANONYMOUS,
&ModuleEnvironmentObject::classOps_,
JS_NULL_CLASS_SPEC,
JS_NULL_CLASS_EXT,
&ModuleEnvironmentObject::objectOps_};
/* static */ ModuleEnvironmentObject* ModuleEnvironmentObject::create(
JSContext* cx, HandleModuleObject module) {
RootedScript script(cx, module->script());
RootedShape shape(cx,
script->bodyScope()->as<ModuleScope>().environmentShape());
MOZ_ASSERT(shape->getObjectClass() == &class_);
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, &class_, TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
gc::AllocKind kind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(CanBeFinalizedInBackground(kind, &class_));
kind = gc::GetBackgroundAllocKind(kind);
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(
cx, obj, NativeObject::create(cx, kind, gc::TenuredHeap, shape, group));
RootedModuleEnvironmentObject env(cx, &obj->as<ModuleEnvironmentObject>());
env->initReservedSlot(MODULE_SLOT, ObjectValue(*module));
if (!JSObject::setSingleton(cx, env)) {
return nullptr;
}
// Initialize this early so that we can manipulate the env object without
// causing assertions.
env->initEnclosingEnvironment(&cx->global()->lexicalEnvironment());
// Initialize all lexical bindings and imports as uninitialized. Imports
// get uninitialized because they have a special TDZ for cyclic imports.
for (BindingIter bi(script); bi; bi++) {
BindingLocation loc = bi.location();
if (loc.kind() == BindingLocation::Kind::Environment &&
BindingKindIsLexical(bi.kind())) {
env->initSlot(loc.slot(), MagicValue(JS_UNINITIALIZED_LEXICAL));
}
}
// It is not be possible to add or remove bindings from a module environment
// after this point as module code is always strict.
#ifdef DEBUG
for (Shape::Range<NoGC> r(env->lastProperty()); !r.empty(); r.popFront()) {
MOZ_ASSERT(!r.front().configurable());
}
MOZ_ASSERT(env->lastProperty()->getObjectFlags() & BaseShape::NOT_EXTENSIBLE);
MOZ_ASSERT(!env->inDictionaryMode());
#endif
return env;
}
ModuleObject& ModuleEnvironmentObject::module() {
return getReservedSlot(MODULE_SLOT).toObject().as<ModuleObject>();
}
IndirectBindingMap& ModuleEnvironmentObject::importBindings() {
return module().importBindings();
}
bool ModuleEnvironmentObject::createImportBinding(JSContext* cx,
HandleAtom importName,
HandleModuleObject module,
HandleAtom localName) {
RootedId importNameId(cx, AtomToId(importName));
RootedId localNameId(cx, AtomToId(localName));
RootedModuleEnvironmentObject env(cx, &module->initialEnvironment());
if (!importBindings().put(cx, importNameId, env, localNameId)) {
return false;
}
return true;
}
bool ModuleEnvironmentObject::hasImportBinding(HandlePropertyName name) {
return importBindings().has(NameToId(name));
}
bool ModuleEnvironmentObject::lookupImport(jsid name,
ModuleEnvironmentObject** envOut,
Shape** shapeOut) {
return importBindings().lookup(name, envOut, shapeOut);
}
void ModuleEnvironmentObject::fixEnclosingEnvironmentAfterCompartmentMerge(
GlobalObject& global) {
setEnclosingEnvironment(&global.lexicalEnvironment());
}
/* static */ bool ModuleEnvironmentObject::lookupProperty(
JSContext* cx, HandleObject obj, HandleId id, MutableHandleObject objp,
MutableHandle<PropertyResult> propp) {
const IndirectBindingMap& bindings =
obj->as<ModuleEnvironmentObject>().importBindings();
Shape* shape;
ModuleEnvironmentObject* env;
if (bindings.lookup(id, &env, &shape)) {
objp.set(env);
propp.setNativeProperty(shape);
return true;
}
RootedNativeObject target(cx, &obj->as<NativeObject>());
if (!NativeLookupOwnProperty<CanGC>(cx, target, id, propp)) {
return false;
}
objp.set(obj);
return true;
}
/* static */ bool ModuleEnvironmentObject::hasProperty(JSContext* cx,
HandleObject obj,
HandleId id,
bool* foundp) {
if (obj->as<ModuleEnvironmentObject>().importBindings().has(id)) {
*foundp = true;
return true;
}
RootedNativeObject self(cx, &obj->as<NativeObject>());
return NativeHasProperty(cx, self, id, foundp);
}
/* static */ bool ModuleEnvironmentObject::getProperty(JSContext* cx,
HandleObject obj,
HandleValue receiver,
HandleId id,
MutableHandleValue vp) {
const IndirectBindingMap& bindings =
obj->as<ModuleEnvironmentObject>().importBindings();
Shape* shape;
ModuleEnvironmentObject* env;
if (bindings.lookup(id, &env, &shape)) {
vp.set(env->getSlot(shape->slot()));
return true;
}
RootedNativeObject self(cx, &obj->as<NativeObject>());
return NativeGetProperty(cx, self, receiver, id, vp);
}
/* static */ bool ModuleEnvironmentObject::setProperty(
JSContext* cx, HandleObject obj, HandleId id, HandleValue v,
HandleValue receiver, JS::ObjectOpResult& result) {
RootedModuleEnvironmentObject self(cx, &obj->as<ModuleEnvironmentObject>());
if (self->importBindings().has(id)) {
return result.failReadOnly();
}
return NativeSetProperty<Qualified>(cx, self, id, v, receiver, result);
}
/* static */ bool ModuleEnvironmentObject::getOwnPropertyDescriptor(
JSContext* cx, HandleObject obj, HandleId id,
MutableHandle<PropertyDescriptor> desc) {
const IndirectBindingMap& bindings =
obj->as<ModuleEnvironmentObject>().importBindings();
Shape* shape;
ModuleEnvironmentObject* env;
if (bindings.lookup(id, &env, &shape)) {
desc.setAttributes(JSPROP_ENUMERATE | JSPROP_PERMANENT);
desc.object().set(obj);
RootedValue value(cx, env->getSlot(shape->slot()));
desc.setValue(value);
desc.assertComplete();
return true;
}
RootedNativeObject self(cx, &obj->as<NativeObject>());
return NativeGetOwnPropertyDescriptor(cx, self, id, desc);
}
/* static */ bool ModuleEnvironmentObject::deleteProperty(
JSContext* cx, HandleObject obj, HandleId id, ObjectOpResult& result) {
return result.failCantDelete();
}
/* static */ bool ModuleEnvironmentObject::newEnumerate(
JSContext* cx, HandleObject obj, AutoIdVector& properties,
bool enumerableOnly) {
RootedModuleEnvironmentObject self(cx, &obj->as<ModuleEnvironmentObject>());
const IndirectBindingMap& bs(self->importBindings());
MOZ_ASSERT(properties.length() == 0);
size_t count = bs.count() + self->slotSpan() - RESERVED_SLOTS;
if (!properties.reserve(count)) {
ReportOutOfMemory(cx);
return false;
}
bs.forEachExportedName([&](jsid name) { properties.infallibleAppend(name); });
for (Shape::Range<NoGC> r(self->lastProperty()); !r.empty(); r.popFront()) {
properties.infallibleAppend(r.front().propid());
}
MOZ_ASSERT(properties.length() == count);
return true;
}
/*****************************************************************************/
const Class WasmInstanceEnvironmentObject::class_ = {
"WasmInstance",
JSCLASS_IS_ANONYMOUS | JSCLASS_HAS_RESERVED_SLOTS(
WasmInstanceEnvironmentObject::RESERVED_SLOTS)};
/* static */ WasmInstanceEnvironmentObject*
WasmInstanceEnvironmentObject::createHollowForDebug(
JSContext* cx, Handle<WasmInstanceScope*> scope) {
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, &class_, TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
RootedShape shape(cx, scope->getEmptyEnvironmentShape(cx));
if (!shape) {
return nullptr;
}
gc::AllocKind kind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(CanBeFinalizedInBackground(kind, &class_));
kind = gc::GetBackgroundAllocKind(kind);
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(
cx, obj, NativeObject::create(cx, kind, gc::DefaultHeap, shape, group));
Rooted<WasmInstanceEnvironmentObject*> callobj(
cx, &obj->as<WasmInstanceEnvironmentObject>());
callobj->initEnclosingEnvironment(&cx->global()->lexicalEnvironment());
callobj->initReservedSlot(SCOPE_SLOT, PrivateGCThingValue(scope));
return callobj;
}
/*****************************************************************************/
const Class WasmFunctionCallObject::class_ = {
"WasmCall",
JSCLASS_IS_ANONYMOUS |
JSCLASS_HAS_RESERVED_SLOTS(WasmFunctionCallObject::RESERVED_SLOTS)};
/* static */ WasmFunctionCallObject*
WasmFunctionCallObject::createHollowForDebug(JSContext* cx,
HandleObject enclosing,
Handle<WasmFunctionScope*> scope) {
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, &class_, TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
RootedShape shape(cx, scope->getEmptyEnvironmentShape(cx));
if (!shape) {
return nullptr;
}
gc::AllocKind kind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(CanBeFinalizedInBackground(kind, &class_));
kind = gc::GetBackgroundAllocKind(kind);
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(
cx, obj, NativeObject::create(cx, kind, gc::DefaultHeap, shape, group));
Rooted<WasmFunctionCallObject*> callobj(cx,
&obj->as<WasmFunctionCallObject>());
callobj->initEnclosingEnvironment(enclosing);
callobj->initReservedSlot(SCOPE_SLOT, PrivateGCThingValue(scope));
return callobj;
}
/*****************************************************************************/
WithEnvironmentObject* WithEnvironmentObject::create(JSContext* cx,
HandleObject object,
HandleObject enclosing,
Handle<WithScope*> scope) {
Rooted<WithEnvironmentObject*> obj(cx);
obj = NewObjectWithNullTaggedProto<WithEnvironmentObject>(
cx, GenericObject, BaseShape::DELEGATE);
if (!obj) {
return nullptr;
}
Value thisv = GetThisValue(object);
obj->initEnclosingEnvironment(enclosing);
obj->initReservedSlot(OBJECT_SLOT, ObjectValue(*object));
obj->initReservedSlot(THIS_SLOT, thisv);
if (scope) {
obj->initReservedSlot(SCOPE_SLOT, PrivateGCThingValue(scope));
} else {
obj->initReservedSlot(SCOPE_SLOT, NullValue());
}
return obj;
}
WithEnvironmentObject* WithEnvironmentObject::createNonSyntactic(
JSContext* cx, HandleObject object, HandleObject enclosing) {
return create(cx, object, enclosing, nullptr);
}
static inline bool IsUnscopableDotName(JSContext* cx, HandleId id) {
return JSID_IS_ATOM(id, cx->names().dotThis) ||
JSID_IS_ATOM(id, cx->names().dotGenerator);
}
/* Implements ES6 8.1.1.2.1 HasBinding steps 7-9. */
static bool CheckUnscopables(JSContext* cx, HandleObject obj, HandleId id,
bool* scopable) {
RootedId unscopablesId(
cx,
SYMBOL_TO_JSID(cx->wellKnownSymbols().get(JS::SymbolCode::unscopables)));
RootedValue v(cx);
if (!GetProperty(cx, obj, obj, unscopablesId, &v)) {
return false;
}
if (v.isObject()) {
RootedObject unscopablesObj(cx, &v.toObject());
if (!GetProperty(cx, unscopablesObj, unscopablesObj, id, &v)) {
return false;
}
*scopable = !ToBoolean(v);
} else {
*scopable = true;
}
return true;
}
static bool with_LookupProperty(JSContext* cx, HandleObject obj, HandleId id,
MutableHandleObject objp,
MutableHandle<PropertyResult> propp) {
// SpiderMonkey-specific: consider internal '.generator' and '.this' names
// to be unscopable.
if (IsUnscopableDotName(cx, id)) {
objp.set(nullptr);
propp.setNotFound();
return true;
}
RootedObject actual(cx, &obj->as<WithEnvironmentObject>().object());
if (!LookupProperty(cx, actual, id, objp, propp)) {
return false;
}
if (propp) {
bool scopable;
if (!CheckUnscopables(cx, actual, id, &scopable)) {
return false;
}
if (!scopable) {
objp.set(nullptr);
propp.setNotFound();
}
}
return true;
}
static bool with_DefineProperty(JSContext* cx, HandleObject obj, HandleId id,
Handle<PropertyDescriptor> desc,
ObjectOpResult& result) {
MOZ_ASSERT(!IsUnscopableDotName(cx, id));
RootedObject actual(cx, &obj->as<WithEnvironmentObject>().object());
return DefineProperty(cx, actual, id, desc, result);
}
static bool with_HasProperty(JSContext* cx, HandleObject obj, HandleId id,
bool* foundp) {
MOZ_ASSERT(!IsUnscopableDotName(cx, id));
RootedObject actual(cx, &obj->as<WithEnvironmentObject>().object());
// ES 8.1.1.2.1 step 3-5.
if (!HasProperty(cx, actual, id, foundp)) {
return false;
}
if (!*foundp) {
return true;
}
// Steps 7-10. (Step 6 is a no-op.)
return CheckUnscopables(cx, actual, id, foundp);
}
static bool with_GetProperty(JSContext* cx, HandleObject obj,
HandleValue receiver, HandleId id,
MutableHandleValue vp) {
MOZ_ASSERT(!IsUnscopableDotName(cx, id));
RootedObject actual(cx, &obj->as<WithEnvironmentObject>().object());
RootedValue actualReceiver(cx, receiver);
if (receiver.isObject() && &receiver.toObject() == obj) {
actualReceiver.setObject(*actual);
}
return GetProperty(cx, actual, actualReceiver, id, vp);
}
static bool with_SetProperty(JSContext* cx, HandleObject obj, HandleId id,
HandleValue v, HandleValue receiver,
ObjectOpResult& result) {
MOZ_ASSERT(!IsUnscopableDotName(cx, id));
RootedObject actual(cx, &obj->as<WithEnvironmentObject>().object());
RootedValue actualReceiver(cx, receiver);
if (receiver.isObject() && &receiver.toObject() == obj) {
actualReceiver.setObject(*actual);
}
return SetProperty(cx, actual, id, v, actualReceiver, result);
}
static bool with_GetOwnPropertyDescriptor(
JSContext* cx, HandleObject obj, HandleId id,
MutableHandle<PropertyDescriptor> desc) {
MOZ_ASSERT(!IsUnscopableDotName(cx, id));
RootedObject actual(cx, &obj->as<WithEnvironmentObject>().object());
return GetOwnPropertyDescriptor(cx, actual, id, desc);
}
static bool with_DeleteProperty(JSContext* cx, HandleObject obj, HandleId id,
ObjectOpResult& result) {
MOZ_ASSERT(!IsUnscopableDotName(cx, id));
RootedObject actual(cx, &obj->as<WithEnvironmentObject>().object());
return DeleteProperty(cx, actual, id, result);
}
static const ObjectOps WithEnvironmentObjectOps = {
with_LookupProperty,
with_DefineProperty,
with_HasProperty,
with_GetProperty,
with_SetProperty,
with_GetOwnPropertyDescriptor,
with_DeleteProperty,
nullptr, /* getElements */
nullptr,
};
const Class WithEnvironmentObject::class_ = {
"With",
JSCLASS_HAS_RESERVED_SLOTS(WithEnvironmentObject::RESERVED_SLOTS) |
JSCLASS_IS_ANONYMOUS,
JS_NULL_CLASS_OPS,
JS_NULL_CLASS_SPEC,
JS_NULL_CLASS_EXT,
&WithEnvironmentObjectOps};
/* static */ NonSyntacticVariablesObject* NonSyntacticVariablesObject::create(
JSContext* cx) {
Rooted<NonSyntacticVariablesObject*> obj(
cx, NewObjectWithNullTaggedProto<NonSyntacticVariablesObject>(
cx, TenuredObject, BaseShape::DELEGATE));
if (!obj) {
return nullptr;
}
MOZ_ASSERT(obj->isUnqualifiedVarObj());
if (!JSObject::setQualifiedVarObj(cx, obj)) {
return nullptr;
}
obj->initEnclosingEnvironment(&cx->global()->lexicalEnvironment());
return obj;
}
const Class NonSyntacticVariablesObject::class_ = {
"NonSyntacticVariablesObject",
JSCLASS_HAS_RESERVED_SLOTS(NonSyntacticVariablesObject::RESERVED_SLOTS) |
JSCLASS_IS_ANONYMOUS};
bool js::CreateNonSyntacticEnvironmentChain(JSContext* cx,
AutoObjectVector& envChain,
MutableHandleObject env,
MutableHandleScope scope) {
RootedObject globalLexical(cx, &cx->global()->lexicalEnvironment());
if (!CreateObjectsForEnvironmentChain(cx, envChain, globalLexical, env)) {
return false;
}
if (!envChain.empty()) {
scope.set(GlobalScope::createEmpty(cx, ScopeKind::NonSyntactic));
if (!scope) {
return false;
}
// The XPConnect subscript loader, which may pass in its own
// environments to load scripts in, expects the environment chain to
// be the holder of "var" declarations. In SpiderMonkey, such objects
// are called "qualified varobjs", the "qualified" part meaning the
// declaration was qualified by "var". There is only sadness.
//
// See JSObject::isQualifiedVarObj.
if (!JSObject::setQualifiedVarObj(cx, env)) {
return false;
}
// Also get a non-syntactic lexical environment to capture 'let' and
// 'const' bindings. To persist lexical bindings, we have a 1-1
// mapping with the final unwrapped environment object (the
// environment that stores the 'var' bindings) and the lexical
// environment.
//
// TODOshu: disallow the subscript loader from using non-distinguished
// objects as dynamic scopes.
env.set(ObjectRealm::get(env).getOrCreateNonSyntacticLexicalEnvironment(
cx, env));
if (!env) {
return false;
}
} else {
scope.set(&cx->global()->emptyGlobalScope());
}
return true;
}
/*****************************************************************************/
/* static */ LexicalEnvironmentObject*
LexicalEnvironmentObject::createTemplateObject(JSContext* cx, HandleShape shape,
HandleObject enclosing,
gc::InitialHeap heap) {
MOZ_ASSERT(shape->getObjectClass() == &LexicalEnvironmentObject::class_);
RootedObjectGroup group(
cx, ObjectGroup::defaultNewGroup(cx, &LexicalEnvironmentObject::class_,
TaggedProto(nullptr)));
if (!group) {
return nullptr;
}
gc::AllocKind allocKind = gc::GetGCObjectKind(shape->numFixedSlots());
MOZ_ASSERT(
CanBeFinalizedInBackground(allocKind, &LexicalEnvironmentObject::class_));
allocKind = GetBackgroundAllocKind(allocKind);
JSObject* obj;
JS_TRY_VAR_OR_RETURN_NULL(
cx, obj, NativeObject::create(cx, allocKind, heap, shape, group));
LexicalEnvironmentObject* env = &obj->as<LexicalEnvironmentObject>();
MOZ_ASSERT(!env->inDictionaryMode());
MOZ_ASSERT(env->isDelegate());
if (enclosing) {
env->initEnclosingEnvironment(enclosing);
}
return env;
}
/* static */ LexicalEnvironmentObject* LexicalEnvironmentObject::create(
JSContext* cx, Handle<LexicalScope*> scope, HandleObject enclosing,
gc::InitialHeap heap) {
cx->check(enclosing);
MOZ_ASSERT(scope->hasEnvironment());
RootedShape shape(cx, scope->environmentShape());
LexicalEnvironmentObject* env =
createTemplateObject(cx, shape, enclosing, heap);
if (!env) {
return nullptr;
}
// All lexical bindings start off uninitialized for TDZ.
uint32_t lastSlot = shape->slot();
MOZ_ASSERT(lastSlot == env->lastProperty()->slot());