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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/DefaultEmitter.h"
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include "frontend/BytecodeEmitter.h" // BytecodeEmitter
#include "vm/Opcodes.h" // JSOp
using namespace js;
using namespace js::frontend;
using mozilla::Nothing;
DefaultEmitter::DefaultEmitter(BytecodeEmitter* bce) : bce_(bce) {}
bool DefaultEmitter::prepareForDefault() {
MOZ_ASSERT(state_ == State::Start);
// [stack] VALUE
ifUndefined_.emplace(bce_);
if (!ifUndefined_->emitIf(Nothing())) {
return false;
}
if (!bce_->emit1(JSOp::Dup)) {
// [stack] VALUE VALUE
return false;
}
if (!bce_->emit1(JSOp::Undefined)) {
// [stack] VALUE VALUE UNDEFINED
return false;
}
if (!bce_->emit1(JSOp::StrictEq)) {
// [stack] VALUE EQ?
return false;
}
if (!ifUndefined_->emitThen()) {
// [stack] VALUE
return false;
}
if (!bce_->emit1(JSOp::Pop)) {
// [stack]
return false;
}
#ifdef DEBUG
state_ = State::Default;
#endif
return true;
}
bool DefaultEmitter::emitEnd() {
MOZ_ASSERT(state_ == State::Default);
// [stack] DEFAULTVALUE
if (!ifUndefined_->emitEnd()) {
// [stack] VALUE/DEFAULTVALUE
return false;
}
ifUndefined_.reset();
#ifdef DEBUG
state_ = State::End;
#endif
return true;
}