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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
#include "frontend/PrivateOpEmitter.h"
#include "frontend/BytecodeEmitter.h"
#include "frontend/NameOpEmitter.h"
#include "vm/Opcodes.h"
#include "vm/ThrowMsgKind.h" // ThrowMsgKind
using namespace js;
using namespace js::frontend;
PrivateOpEmitter::PrivateOpEmitter(BytecodeEmitter* bce, Kind kind,
TaggedParserAtomIndex name)
: bce_(bce), kind_(kind), name_(name) {
MOZ_ASSERT(kind_ != Kind::Delete);
}
bool PrivateOpEmitter::init() {
// Static analysis needs us to initialise this to something, so use Dynamic()
NameLocation loc = NameLocation::Dynamic();
bce_->lookupPrivate(name_, loc, brandLoc_);
loc_ = mozilla::Some(loc);
return true;
}
bool PrivateOpEmitter::emitLoad(TaggedParserAtomIndex name,
const NameLocation& loc) {
NameOpEmitter noe(bce_, name, loc, NameOpEmitter::Kind::Get);
return noe.emitGet();
}
bool PrivateOpEmitter::emitLoadPrivateBrand() {
return emitLoad(TaggedParserAtomIndex::WellKnown::dot_privateBrand_(),
*brandLoc_);
}
bool PrivateOpEmitter::emitBrandCheck() {
MOZ_ASSERT(state_ == State::Reference);
if (isBrandCheck()) {
// Emit a CheckPrivateField CheckRhs; note: The message is irrelvant here,
// it will never be thrown, so DoubleInit was chosen arbitrarily.
if (!bce_->emitCheckPrivateField(ThrowCondition::OnlyCheckRhs,
ThrowMsgKind::PrivateDoubleInit)) {
// [stack] OBJ KEY BBOOL
return false;
}
return true;
}
// [stack] OBJ KEY
if (isFieldInit()) {
if (!bce_->emitCheckPrivateField(ThrowCondition::ThrowHas,
ThrowMsgKind::PrivateDoubleInit)) {
// [stack] OBJ KEY false
return false;
}
} else {
bool assigning =
isSimpleAssignment() || isCompoundAssignment() || isIncDec();
if (!bce_->emitCheckPrivateField(ThrowCondition::ThrowHasNot,
assigning
? ThrowMsgKind::MissingPrivateOnSet
: ThrowMsgKind::MissingPrivateOnGet)) {
// [stack] OBJ KEY true
return false;
}
}
return true;
}
bool PrivateOpEmitter::emitReference() {
MOZ_ASSERT(state_ == State::Start);
if (!init()) {
return false;
}
if (brandLoc_) {
if (!emitLoadPrivateBrand()) {
// [stack] OBJ BRAND
return false;
}
} else {
if (!emitLoad(name_, loc_.ref())) {
// [stack] OBJ NAME
return false;
}
}
#ifdef DEBUG
state_ = State::Reference;
#endif
return true;
}
bool PrivateOpEmitter::skipReference() {
MOZ_ASSERT(state_ == State::Start);
if (!init()) {
return false;
}
#ifdef DEBUG
state_ = State::Reference;
#endif
return true;
}
bool PrivateOpEmitter::emitGet() {
MOZ_ASSERT(state_ == State::Reference);
// [stack] OBJ NAME
if (brandLoc_) {
// Note that the decision of what we leave on the stack depends on kind_,
// not loc_->bindingKind(). We can't emit code for a call just because this
// private member is a method. `obj.#method` is allowed without a call,
// just fetching the function object (it's useful in code like
// `obj.#method.bind(...)`). Even if the user says `obj.#method += 7`, we
// emit honest bytecode for the brand check, method load, and addition, and
// throw the error later. This preserves stack nuses/ndefs balance.
if (!emitBrandCheck()) {
// [stack] OBJ BRAND true
return false;
}
if (isCompoundAssignment()) {
if (!bce_->emit1(JSOp::Pop)) {
// [stack] OBJ BRAND
return false;
}
} else if (isCall()) {
if (!bce_->emitPopN(2)) {
// [stack] OBJ
return false;
}
} else {
if (!bce_->emitPopN(3)) {
// [stack]
return false;
}
}
if (!emitLoad(name_, loc_.ref())) {
// [stack] OBJ BRAND METHOD # if isCompoundAssignment
// [stack] OBJ METHOD # if call
// [stack] METHOD # otherwise
return false;
}
} else {
if (isCall()) {
if (!bce_->emitDupAt(1)) {
// [stack] OBJ NAME OBJ
return false;
}
if (!bce_->emit1(JSOp::Swap)) {
// [stack] OBJ OBJ NAME
return false;
}
}
// [stack] OBJ? OBJ NAME
if (!emitBrandCheck()) {
// [stack] OBJ? OBJ NAME true
return false;
}
if (!bce_->emit1(JSOp::Pop)) {
// [stack] OBJ? OBJ NAME
return false;
}
if (isCompoundAssignment()) {
if (!bce_->emit1(JSOp::Dup2)) {
// [stack] OBJ NAME OBJ NAME
return false;
}
}
if (!bce_->emitElemOpBase(JSOp::GetElem)) {
// [stack] OBJ NAME VALUE # if isCompoundAssignment
// [stack] OBJ METHOD # if Call
// [stack] VALUE # otherwise
return false;
}
}
if (isCall()) {
if (!bce_->emit1(JSOp::Swap)) {
// [stack] METHOD OBJ
return false;
}
}
// [stack] OBJ NAME VALUE # if isCompoundAssignment
// [stack] METHOD OBJ # if call
// [stack] VALUE # otherwise
#ifdef DEBUG
state_ = State::Get;
#endif
return true;
}
bool PrivateOpEmitter::emitGetForCallOrNew() { return emitGet(); }
bool PrivateOpEmitter::emitAssignment() {
MOZ_ASSERT(isSimpleAssignment() || isFieldInit() || isCompoundAssignment());
MOZ_ASSERT_IF(!isCompoundAssignment(), state_ == State::Reference);
MOZ_ASSERT_IF(isCompoundAssignment(), state_ == State::Get);
// [stack] OBJ KEY RHS
if (brandLoc_) {
if (!bce_->emit2(JSOp::ThrowMsg,
uint8_t(ThrowMsgKind::AssignToPrivateMethod))) {
return false;
}
// Balance the expression stack.
if (!bce_->emitPopN(2)) {
// [stack] OBJ
return false;
}
} else {
// Emit a brand check. If this is compound assignment, emitGet() already
// emitted a check for this object and key. There's no point checking
// again--a private field can't be removed from an object.
if (!isCompoundAssignment()) {
if (!bce_->emitUnpickN(2)) {
// [stack] RHS OBJ KEY
return false;
}
if (!emitBrandCheck()) {
// [stack] RHS OBJ KEY BOOL
return false;
}
if (!bce_->emit1(JSOp::Pop)) {
// [stack] RHS OBJ KEY
return false;
}
if (!bce_->emitPickN(2)) {
// [stack] OBJ KEY RHS
return false;
}
}
JSOp setOp = isFieldInit() ? JSOp::InitElem : JSOp::StrictSetElem;
if (!bce_->emitElemOpBase(setOp)) {
// [stack] RHS
return false;
}
}
#ifdef DEBUG
state_ = State::Assignment;
#endif
return true;
}
bool PrivateOpEmitter::emitIncDec(ValueUsage valueUsage) {
MOZ_ASSERT(state_ == State::Reference);
MOZ_ASSERT(isIncDec());
// [stack] OBJ NAME
if (!bce_->emitDupAt(1, 2)) {
// [stack] OBJ NAME OBJ NAME
return false;
}
if (!emitGet()) {
// [stack] OBJ NAME VALUE
return false;
}
MOZ_ASSERT(state_ == State::Get);
JSOp incOp = isInc() ? JSOp::Inc : JSOp::Dec;
if (!bce_->emit1(JSOp::ToNumeric)) {
// [stack] OBJ NAME N
return false;
}
if (isPostIncDec() && valueUsage == ValueUsage::WantValue) {
// [stack] OBJ NAME N
if (!bce_->emit1(JSOp::Dup)) {
// [stack] OBJ NAME N N
return false;
}
if (!bce_->emit2(JSOp::Unpick, 3)) {
// [stack] N OBJ NAME N
return false;
}
}
if (!bce_->emit1(incOp)) {
// [stack] N? OBJ NAME N+1
return false;
}
if (brandLoc_) {
if (!bce_->emit2(JSOp::ThrowMsg,
uint8_t(ThrowMsgKind::AssignToPrivateMethod))) {
return false;
}
// Balance the expression stack.
if (!bce_->emitPopN(2)) {
// [stack] N? N+1
return false;
}
} else {
if (!bce_->emitElemOpBase(JSOp::StrictSetElem)) {
// [stack] N? N+1
return false;
}
}
if (isPostIncDec() && valueUsage == ValueUsage::WantValue) {
if (!bce_->emit1(JSOp::Pop)) {
// [stack] N
return false;
}
}
return true;
}