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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
#ifndef frontend_DefaultEmitter_h
#define frontend_DefaultEmitter_h
#include "mozilla/Attributes.h" // MOZ_STACK_CLASS
#include "mozilla/Maybe.h" // Maybe
#include "frontend/IfEmitter.h" // IfEmitter
namespace js {
namespace frontend {
struct BytecodeEmitter;
// Class for emitting default parameter or default value.
//
// Usage: (check for the return value is omitted for simplicity)
//
// `x = 10` in `function (x = 10) {}`
// // the value of arguments[0] is on the stack
// DefaultEmitter de(this);
// de.prepareForDefault();
// emit(10);
// de.emitEnd();
//
class MOZ_STACK_CLASS DefaultEmitter {
BytecodeEmitter* bce_;
mozilla::Maybe<IfEmitter> ifUndefined_;
#ifdef DEBUG
// The state of this emitter.
//
// +-------+ prepareForDefault +---------+ emitEnd +-----+
// | Start |------------------>| Default |-------->| End |
// +-------+ +---------+ +-----+
enum class State {
// The initial state.
Start,
// After calling prepareForDefault.
Default,
// After calling emitEnd.
End
};
State state_ = State::Start;
#endif
public:
explicit DefaultEmitter(BytecodeEmitter* bce);
[[nodiscard]] bool prepareForDefault();
[[nodiscard]] bool emitEnd();
};
} /* namespace frontend */
} /* namespace js */
#endif /* frontend_LabelEmitter_h */