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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/. */
#ifndef frontend_LabelEmitter_h
#define frontend_LabelEmitter_h
#include "mozilla/Attributes.h" // MOZ_STACK_CLASS
#include "mozilla/Maybe.h" // Maybe
#include "frontend/BytecodeControlStructures.h" // LabelControl
namespace js {
namespace frontend {
struct BytecodeEmitter;
class TaggedParserAtomIndex;
// Class for emitting labeled statement.
//
// Usage: (check for the return value is omitted for simplicity)
//
// `label: expr;`
// LabelEmitter le(this);
// le.emitLabel(name_of_label);
// emit(expr);
// le.emitEnd();
//
class MOZ_STACK_CLASS LabelEmitter {
BytecodeEmitter* bce_;
mozilla::Maybe<LabelControl> controlInfo_;
#ifdef DEBUG
// The state of this emitter.
//
// +-------+ emitLabel +-------+ emitEnd +-----+
// | Start |---------->| Label |-------->| End |
// +-------+ +-------+ +-----+
enum class State {
// The initial state.
Start,
// After calling emitLabel.
Label,
// After calling emitEnd.
End
};
State state_ = State::Start;
#endif
public:
explicit LabelEmitter(BytecodeEmitter* bce) : bce_(bce) {}
void emitLabel(TaggedParserAtomIndex name);
[[nodiscard]] bool emitEnd();
};
} /* namespace frontend */
} /* namespace js */
#endif /* frontend_LabelEmitter_h */